Hippocrates first described endotracheal intubation in the 5th century BC. Mechanical ventilation progressed through the centuries with innovations like Paracelsus using bellows in 1530 and Vesalius recognizing artificial respiration through tracheostomy in dogs in the 16th century. The development of positive pressure ventilation in the 1950s helped greatly during polio epidemics. Key events included the iron lung in 1929 and intensive use of positive pressure ventilation in Scandinavia and the US in the 1950s. The document outlines the historical aspects and developments of mechanical ventilation from ancient times through the modern era.
Recruitment Maneuvers in ARDS Dr Chennamchetty Vijay KumarVizae Kumar Chennam
This document discusses recruitment maneuvers for mechanically ventilated patients. It begins with a case study of a patient presenting with respiratory failure. It then provides definitions and the physiological rationale for recruitment maneuvers, including how alveolar collapse occurs in ARDS. Different types of recruitment maneuvers are described, as well as factors that influence their effectiveness. Clinical trials on recruitment maneuvers are summarized, which found no significant reduction in mortality but some improvement in secondary outcomes. Limitations of recruitment maneuvers are discussed, such as potential hemodynamic effects. The document concludes with emphasizing the complexity of lung recruitment and ongoing controversies regarding recruitment maneuvers.
The document discusses the case of a 27-year-old postpartum woman presenting with worsening dyspnea and hypoxia. It then reviews the key considerations and management strategies for acute respiratory distress syndrome (ARDS), including low tidal volume ventilation, open lung strategies using recruitment maneuvers and high positive end-expiratory pressure, unconventional approaches like airway pressure release ventilation and high frequency oscillatory ventilation, and adjunctive therapies such as prone positioning. The optimal ventilator mode, settings, and adjunctive strategies depend on the individual patient's severity of lung injury and response to different interventions.
APRV is a ventilation mode that applies CPAP at a high pressure for a prolonged period of time to recruit and maintain lung volume, followed by brief releases to a lower pressure to allow for exhalation and CO2 removal. It aims to preserve spontaneous breathing. APRV is indicated for ARDS management and postoperative atelectasis and has benefits like improved oxygenation and reduced sedation needs but risks include increased work of breathing and worsening of air leaks. Studies comparing APRV to other modes in ARDS patients have found similar outcomes but more research is still needed to determine its full utility.
This document provides an overview of capnography including:
1) The objectives of describing ventilation, perfusion, and their relationship as assessed by capnography.
2) A description of the normal capnogram waveform and factors that can cause abnormal waveforms related to airway, breathing, and circulation problems.
3) Clinical applications of capnography including confirming endotracheal tube placement, assessing ventilation status, and predicting outcomes of cardiac arrest resuscitation.
This document discusses various aspects of mechanical ventilation including indications, types of breaths, modes, settings and principles. It begins by outlining the objectives and indications for mechanical ventilation. It then describes non-invasive positive pressure ventilation and invasive mechanical ventilation. The principles of mechanical ventilation are explained including types of breaths, triggering, cycling and basic mechanics. Finally, the document outlines various ventilator modes like assist-control, SIMV and pressure support as well as important settings like tidal volume, respiratory rate, PEEP, flow rate and FiO2.
Mechanical ventilation provides positive pressure to move gas into the lungs. There are two main types: volume-controlled ventilation which preselects tidal volume and pressure-controlled ventilation which preselects pressure. Modes include controlled mandatory ventilation (CMV), assisted control ventilation (AC), and synchronized intermittent mandatory ventilation (SIMV). Positive end-expiratory pressure (PEEP) is used to prevent alveolar collapse. Weaning involves gradually reducing ventilator support by shifting modes and rates until the patient can breathe independently. Complications include barotrauma, infection, and weakness.
Respiratory Physiology & Respiratory Function During AnesthesiaDang Thanh Tuan
This document summarizes respiratory physiology and function during anesthesia. It discusses factors related to respiratory function including gravity-determined distribution of perfusion and ventilation. It also covers non-gravitational determinants of pulmonary vascular resistance and blood flow distribution. Finally, it examines oxygen and carbon dioxide transport through the lungs.
Mechanical Ventilation Weaning From Mechanical VentilationDang Thanh Tuan
- The document discusses various parameters and criteria used to determine when a patient can be safely disconnected from mechanical ventilation, including respiratory muscle strength, gas exchange, respiratory rate and volume.
- Common methods for gradually weaning a patient from mechanical ventilation are described, such as a T-piece trial, pressure support ventilation, and gradually decreasing the rate of support on SIMV.
- Failure criteria are outlined, including rapid shallow breathing, increased heart rate or blood pressure, distress signs. Determining the cause of failure and correcting it is important before subsequent weaning trials.
Recruitment Maneuvers in ARDS Dr Chennamchetty Vijay KumarVizae Kumar Chennam
This document discusses recruitment maneuvers for mechanically ventilated patients. It begins with a case study of a patient presenting with respiratory failure. It then provides definitions and the physiological rationale for recruitment maneuvers, including how alveolar collapse occurs in ARDS. Different types of recruitment maneuvers are described, as well as factors that influence their effectiveness. Clinical trials on recruitment maneuvers are summarized, which found no significant reduction in mortality but some improvement in secondary outcomes. Limitations of recruitment maneuvers are discussed, such as potential hemodynamic effects. The document concludes with emphasizing the complexity of lung recruitment and ongoing controversies regarding recruitment maneuvers.
The document discusses the case of a 27-year-old postpartum woman presenting with worsening dyspnea and hypoxia. It then reviews the key considerations and management strategies for acute respiratory distress syndrome (ARDS), including low tidal volume ventilation, open lung strategies using recruitment maneuvers and high positive end-expiratory pressure, unconventional approaches like airway pressure release ventilation and high frequency oscillatory ventilation, and adjunctive therapies such as prone positioning. The optimal ventilator mode, settings, and adjunctive strategies depend on the individual patient's severity of lung injury and response to different interventions.
APRV is a ventilation mode that applies CPAP at a high pressure for a prolonged period of time to recruit and maintain lung volume, followed by brief releases to a lower pressure to allow for exhalation and CO2 removal. It aims to preserve spontaneous breathing. APRV is indicated for ARDS management and postoperative atelectasis and has benefits like improved oxygenation and reduced sedation needs but risks include increased work of breathing and worsening of air leaks. Studies comparing APRV to other modes in ARDS patients have found similar outcomes but more research is still needed to determine its full utility.
This document provides an overview of capnography including:
1) The objectives of describing ventilation, perfusion, and their relationship as assessed by capnography.
2) A description of the normal capnogram waveform and factors that can cause abnormal waveforms related to airway, breathing, and circulation problems.
3) Clinical applications of capnography including confirming endotracheal tube placement, assessing ventilation status, and predicting outcomes of cardiac arrest resuscitation.
This document discusses various aspects of mechanical ventilation including indications, types of breaths, modes, settings and principles. It begins by outlining the objectives and indications for mechanical ventilation. It then describes non-invasive positive pressure ventilation and invasive mechanical ventilation. The principles of mechanical ventilation are explained including types of breaths, triggering, cycling and basic mechanics. Finally, the document outlines various ventilator modes like assist-control, SIMV and pressure support as well as important settings like tidal volume, respiratory rate, PEEP, flow rate and FiO2.
Mechanical ventilation provides positive pressure to move gas into the lungs. There are two main types: volume-controlled ventilation which preselects tidal volume and pressure-controlled ventilation which preselects pressure. Modes include controlled mandatory ventilation (CMV), assisted control ventilation (AC), and synchronized intermittent mandatory ventilation (SIMV). Positive end-expiratory pressure (PEEP) is used to prevent alveolar collapse. Weaning involves gradually reducing ventilator support by shifting modes and rates until the patient can breathe independently. Complications include barotrauma, infection, and weakness.
Respiratory Physiology & Respiratory Function During AnesthesiaDang Thanh Tuan
This document summarizes respiratory physiology and function during anesthesia. It discusses factors related to respiratory function including gravity-determined distribution of perfusion and ventilation. It also covers non-gravitational determinants of pulmonary vascular resistance and blood flow distribution. Finally, it examines oxygen and carbon dioxide transport through the lungs.
Mechanical Ventilation Weaning From Mechanical VentilationDang Thanh Tuan
- The document discusses various parameters and criteria used to determine when a patient can be safely disconnected from mechanical ventilation, including respiratory muscle strength, gas exchange, respiratory rate and volume.
- Common methods for gradually weaning a patient from mechanical ventilation are described, such as a T-piece trial, pressure support ventilation, and gradually decreasing the rate of support on SIMV.
- Failure criteria are outlined, including rapid shallow breathing, increased heart rate or blood pressure, distress signs. Determining the cause of failure and correcting it is important before subsequent weaning trials.
The document discusses ventilation and different modes of noninvasive ventilation. It provides details on:
1) How ventilation works through pressure differences that cause air to flow into and out of the lungs. Different factors like resistance and Boyle's law impact this process.
2) The history and development of noninvasive ventilation, from early negative pressure devices to current use of positive pressure ventilation delivered noninvasively through masks.
3) Modes of noninvasive positive pressure ventilation including volume ventilation, pressure ventilation, bilevel PAP, and CPAP. The benefits and limitations of noninvasive ventilation are also summarized.
NIV, or non-invasive ventilation, is a form of ventilation therapy that is applied non-invasively through a mask rather than an endotracheal tube. It is commonly used to treat conditions like COPD exacerbations, pulmonary edema, and respiratory failure. Key settings that must be adjusted include IPAP, EPAP, Ti min/max, trigger sensitivity, and backup rate. Modes include spontaneous, timed, and bi-level positive airway pressure. Proper mask fitting and troubleshooting issues like leaks are important for ensuring effective ventilation. Regular monitoring of parameters like ABGs, SpO2, and ventilation is needed to optimize NIV therapy.
The document discusses various aspects of mechanical ventilation settings that impact patient-ventilator synchrony and work of breathing. These include:
1. Rise time, which is the rate of pressure rise during inspiration. Slower rise times can reduce work of breathing.
2. Expiratory sensitivity, which determines the point at which expiration is triggered. Adjusting this setting to account for leaks can improve synchrony.
3. Flow triggering, which detects very small amounts of inspiratory effort from the patient. This results in lower work of breathing compared to pressure triggering.
1) Recruitment maneuvers (RMs) aim to reopen collapsed alveoli in ARDS patients through temporarily increasing transpulmonary pressure. Common types include sighs, sustained inflations, and stepwise increases in pressure.
2) While RMs often improve short-term oxygenation, clinical trials have found no evidence of reduced mortality or improved outcomes. One large trial found RMs may actually increase mortality.
3) Not all ARDS patients respond equally to RMs due to factors like etiology, severity, and lung recruitability. RMs should only be considered for hypoxemic individuals based on an individual risk-benefit assessment.
Non-invasive ventilation (NIV) provides ventilatory support without intubation through a non-invasive interface like a mask. It is used initially to treat type 2 respiratory failure and prevent need for mechanical ventilation. Benefits include avoiding complications of intubation and improving outcomes by reducing mortality, morbidity, ICU/hospital stay, and costs. NIV is appropriate for patients with acute or acute on chronic respiratory failure who are cooperative, hemodynamically stable, and have an adequate cough reflex. Factors determining success include careful patient selection, skilled application and monitoring, and timely transition to invasive ventilation if needed.
Tissue oxygenation involves the cascade of oxygen from the atmosphere to the mitochondria in cells. Oxygen partial pressure progressively decreases from 150 mmHg in inspired air to 10-20 mmHg in cell mitochondria. Factors like ventilation, cardiac output, hemoglobin levels, and oxygen consumption can impact oxygen levels at different points in the cascade. Clinicians assess tissue oxygenation using variables derived from oxygen delivery and uptake, such as oxygen saturation, lactate levels, and base deficit. Monitoring these factors provides insight into a patient's oxygenation status.
1. The document discusses various modes of mechanical ventilation including volume control, pressure control, SIMV, and PSV. It describes the settings, parameters, and considerations for each mode.
2. Initial ventilator settings should aim for adequate oxygenation and ventilation while minimizing work of breathing. Settings like tidal volume, respiratory rate, and PEEP are adjusted based on factors like patient size and condition.
3. Weaning from mechanical ventilation involves gradually reducing support through methods like spontaneous breathing trials, decreasing SIMV frequency, and lowering pressure support levels to assess the patient's ability to breathe independently. Readiness criteria and a stepwise protocol are
The document provides an overview of mechanical ventilation, including its history and various modes. It begins with the origins of negative-pressure ventilators like iron lungs and the later development of positive-pressure ventilators. The main goals of ventilation are to facilitate carbon dioxide release and oxygen delivery. Various modes are described that can be used for invasive or non-invasive ventilation. Settings like PEEP, respiratory rate, tidal volume, and FiO2 are outlined that can be adjusted to optimize oxygenation and ventilation. Indications for intubation and criteria for safely extubating patients are also reviewed.
Ventilator Management In Different Disease EntitiesDang Thanh Tuan
The document discusses ventilator management in different disease entities. It covers indications for mechanical ventilation in conditions like respiratory failure, ARDS, COPD, chest trauma, and head injury. For ARDS specifically, it summarizes the key findings of the NIH ARDS Network trial which demonstrated that a lower tidal volume strategy of 6 ml/kg predicted body weight reduced mortality compared to the traditional higher tidal volume approach.
Non-invasive ventilation (NIV) is the use of breathing support administered through a face mask or nasal mask. Learn more about NIV in this presentation by Dr Somnath Longani, consultant Anaesthesiologist & Intensivist, Midland Healthcare & Research Center, lucknow
https://midlandhealthcare.org/
This document discusses strategies for liberating patients from mechanical ventilation. It outlines key factors that indicate readiness to wean, including improved respiratory function and organ system stability. Two common approaches to weaning are described: gradual weaning using methods like pressure support ventilation or spontaneous breathing trials followed by extubation if tolerated. Protocols using objective criteria can standardize and expedite the weaning process. Factors that may cause weaning failure include respiratory issues, cardiovascular problems, or infection. Readiness is assessed through measurements of ventilatory drive, muscle strength, and breathing patterns.
This document provides an overview of ventilator basics and parameters including:
1) It describes the basic components and parameters of ventilators such as modes, controls, triggers and adjunct therapies.
2) It explains some common ventilator modes like pressure control ventilation, BiPAP, and APRV and notes some safety considerations.
3) It outlines potential complications from mechanical ventilation and stresses the importance of monitoring patients and equipment.
Mechanical ventilation ppt including airway, ventilator, tubings and connections, nursing management, trouble shooting common problems and issues, suctioning etc.
This document discusses several advanced modes of mechanical ventilation. It begins by describing triggered modes like volume support (VS) and proportional assist ventilation (PAV) which provide pressure support that varies based on patient effort. It then covers hybrid modes like volume-assured pressure support and pressure regulated volume control (PRVC) which use dual controls. Newer dual-controlled modes are presented that regulate pressure and volume both within and between breaths. Modes like adaptive support ventilation (ASV) automatically adapt settings to patient changes. Pros, cons and indications are provided for some of the more complex modes.
1. Functional residual capacity (FRC) is the amount of air in the lungs after a normal expiration and is dependent on factors like sex, age, height, and weight. FRC increases with age and decreases with weight.
2. Positive end-expiratory pressure (PEEP) maintains a positive pressure during expiration to keep alveoli inflated, which increases functional residual capacity and improves oxygenation. PEEP is indicated for refractory hypoxemia, intrapulmonary shunts, and decreased FRC and lung compliance.
3. Complications of PEEP include decreased venous return, decreased cardiac output, barotrauma, increased intracranial pressure, and altered renal function
APRV (Airway Pressure Release Ventilation) is a ventilation mode that applies continuous positive airway pressure (CPAP) for a prolonged high-pressure phase (T high) to recruit and maintain lung volume. It then has a brief low-pressure release phase (T low) where most ventilation and CO2 removal occurs. Compared to conventional ventilation, APRV may cause less ventilator-induced lung injury due to maintaining higher end-expiratory lung volumes without repetitive opening/closing of alveoli. It also allows for spontaneous breathing which improves patient comfort and outcomes. While APRV does not reduce mortality, it can improve other outcomes such as shorter ventilation times and ICU stays.
Mechanical ventilation is a therapeutic method that uses physical devices to assist or replace spontaneous breathing. There are two main types: negative pressure ventilation which applies pressure lower than atmospheric to the chest, and positive pressure ventilation which applies pressure higher than atmospheric to the lungs. Positive pressure ventilation is more commonly used today. It is important to carefully monitor patients on mechanical ventilation to optimize ventilation and prevent lung injury, through monitoring pressures, volumes, oxygen levels and CO2 levels. The goals are to provide adequate gas exchange while applying the lowest possible pressures and volumes to the lungs.
Rapid sequence induction and intubation (RSII) is a technique used to minimize the risk of pulmonary aspiration by rapidly inducing unconsciousness and paralysis before intubating the trachea. Key elements of RSII include pre-oxygenating the patient, administering sedative and neuromuscular blocking agents to quickly induce unconsciousness and paralysis, applying cricoid pressure, and promptly intubating the trachea with minimal ventilation. Indications for RSII include patients with full stomachs or gastrointestinal pathology who are at higher risk of aspiration. Contraindications include total airway obstruction or loss of airway landmarks. Potential complications include difficult or failed airway, hypoxia, hypotension,
1) ARDS is characterized by hypoxemia, bilateral lung infiltrates, and respiratory failure not fully explained by cardiac failure. The Berlin definition classifies ARDS as mild, moderate, or severe based on oxygenation levels.
2) Management of ARDS focuses on treating underlying causes, preventing complications, and using ventilator strategies like low tidal volume ventilation to prevent ventilator-induced lung injury.
3) Other ventilator strategies discussed include prone positioning, neuromuscular blockade, recruitment maneuvers, and extracorporeal membrane oxygenation for severe cases, though evidence on benefits is mixed.
New modes of mechanical ventilation TRCchandra talur
The document discusses newer modes of mechanical ventilation that were introduced to address clinical issues like poor patient-ventilator synchrony, prolonged weaning times, and ventilator-induced lung injury. It classifies the newer modes as dual modes that combine volume and pressure control, modes that adapt to lung characteristics, and knowledge-based weaning modes. It provides more details on proportional assist ventilation (PAV+), airway pressure release ventilation (APRV/BIPAP), and Smartcare—modes that aim to improve synchrony, maintain high functional residual capacity, and reduce workload for clinicians respectively.
This document provides an overview of mechanical ventilation, including its history, types of ventilators, modes of ventilation, and indications for use. It begins with a definition of mechanical ventilation and descriptions of negative pressure and positive pressure machines. It then covers various modes of ventilation including volume-targeted modes, pressure-regulated modes, and modes based on breath initiation such as assist-control, SIMV, and pressure support. The document concludes with a section on indications for mechanical ventilation and complications that can arise.
The document discusses ventilation and different modes of noninvasive ventilation. It provides details on:
1) How ventilation works through pressure differences that cause air to flow into and out of the lungs. Different factors like resistance and Boyle's law impact this process.
2) The history and development of noninvasive ventilation, from early negative pressure devices to current use of positive pressure ventilation delivered noninvasively through masks.
3) Modes of noninvasive positive pressure ventilation including volume ventilation, pressure ventilation, bilevel PAP, and CPAP. The benefits and limitations of noninvasive ventilation are also summarized.
NIV, or non-invasive ventilation, is a form of ventilation therapy that is applied non-invasively through a mask rather than an endotracheal tube. It is commonly used to treat conditions like COPD exacerbations, pulmonary edema, and respiratory failure. Key settings that must be adjusted include IPAP, EPAP, Ti min/max, trigger sensitivity, and backup rate. Modes include spontaneous, timed, and bi-level positive airway pressure. Proper mask fitting and troubleshooting issues like leaks are important for ensuring effective ventilation. Regular monitoring of parameters like ABGs, SpO2, and ventilation is needed to optimize NIV therapy.
The document discusses various aspects of mechanical ventilation settings that impact patient-ventilator synchrony and work of breathing. These include:
1. Rise time, which is the rate of pressure rise during inspiration. Slower rise times can reduce work of breathing.
2. Expiratory sensitivity, which determines the point at which expiration is triggered. Adjusting this setting to account for leaks can improve synchrony.
3. Flow triggering, which detects very small amounts of inspiratory effort from the patient. This results in lower work of breathing compared to pressure triggering.
1) Recruitment maneuvers (RMs) aim to reopen collapsed alveoli in ARDS patients through temporarily increasing transpulmonary pressure. Common types include sighs, sustained inflations, and stepwise increases in pressure.
2) While RMs often improve short-term oxygenation, clinical trials have found no evidence of reduced mortality or improved outcomes. One large trial found RMs may actually increase mortality.
3) Not all ARDS patients respond equally to RMs due to factors like etiology, severity, and lung recruitability. RMs should only be considered for hypoxemic individuals based on an individual risk-benefit assessment.
Non-invasive ventilation (NIV) provides ventilatory support without intubation through a non-invasive interface like a mask. It is used initially to treat type 2 respiratory failure and prevent need for mechanical ventilation. Benefits include avoiding complications of intubation and improving outcomes by reducing mortality, morbidity, ICU/hospital stay, and costs. NIV is appropriate for patients with acute or acute on chronic respiratory failure who are cooperative, hemodynamically stable, and have an adequate cough reflex. Factors determining success include careful patient selection, skilled application and monitoring, and timely transition to invasive ventilation if needed.
Tissue oxygenation involves the cascade of oxygen from the atmosphere to the mitochondria in cells. Oxygen partial pressure progressively decreases from 150 mmHg in inspired air to 10-20 mmHg in cell mitochondria. Factors like ventilation, cardiac output, hemoglobin levels, and oxygen consumption can impact oxygen levels at different points in the cascade. Clinicians assess tissue oxygenation using variables derived from oxygen delivery and uptake, such as oxygen saturation, lactate levels, and base deficit. Monitoring these factors provides insight into a patient's oxygenation status.
1. The document discusses various modes of mechanical ventilation including volume control, pressure control, SIMV, and PSV. It describes the settings, parameters, and considerations for each mode.
2. Initial ventilator settings should aim for adequate oxygenation and ventilation while minimizing work of breathing. Settings like tidal volume, respiratory rate, and PEEP are adjusted based on factors like patient size and condition.
3. Weaning from mechanical ventilation involves gradually reducing support through methods like spontaneous breathing trials, decreasing SIMV frequency, and lowering pressure support levels to assess the patient's ability to breathe independently. Readiness criteria and a stepwise protocol are
The document provides an overview of mechanical ventilation, including its history and various modes. It begins with the origins of negative-pressure ventilators like iron lungs and the later development of positive-pressure ventilators. The main goals of ventilation are to facilitate carbon dioxide release and oxygen delivery. Various modes are described that can be used for invasive or non-invasive ventilation. Settings like PEEP, respiratory rate, tidal volume, and FiO2 are outlined that can be adjusted to optimize oxygenation and ventilation. Indications for intubation and criteria for safely extubating patients are also reviewed.
Ventilator Management In Different Disease EntitiesDang Thanh Tuan
The document discusses ventilator management in different disease entities. It covers indications for mechanical ventilation in conditions like respiratory failure, ARDS, COPD, chest trauma, and head injury. For ARDS specifically, it summarizes the key findings of the NIH ARDS Network trial which demonstrated that a lower tidal volume strategy of 6 ml/kg predicted body weight reduced mortality compared to the traditional higher tidal volume approach.
Non-invasive ventilation (NIV) is the use of breathing support administered through a face mask or nasal mask. Learn more about NIV in this presentation by Dr Somnath Longani, consultant Anaesthesiologist & Intensivist, Midland Healthcare & Research Center, lucknow
https://midlandhealthcare.org/
This document discusses strategies for liberating patients from mechanical ventilation. It outlines key factors that indicate readiness to wean, including improved respiratory function and organ system stability. Two common approaches to weaning are described: gradual weaning using methods like pressure support ventilation or spontaneous breathing trials followed by extubation if tolerated. Protocols using objective criteria can standardize and expedite the weaning process. Factors that may cause weaning failure include respiratory issues, cardiovascular problems, or infection. Readiness is assessed through measurements of ventilatory drive, muscle strength, and breathing patterns.
This document provides an overview of ventilator basics and parameters including:
1) It describes the basic components and parameters of ventilators such as modes, controls, triggers and adjunct therapies.
2) It explains some common ventilator modes like pressure control ventilation, BiPAP, and APRV and notes some safety considerations.
3) It outlines potential complications from mechanical ventilation and stresses the importance of monitoring patients and equipment.
Mechanical ventilation ppt including airway, ventilator, tubings and connections, nursing management, trouble shooting common problems and issues, suctioning etc.
This document discusses several advanced modes of mechanical ventilation. It begins by describing triggered modes like volume support (VS) and proportional assist ventilation (PAV) which provide pressure support that varies based on patient effort. It then covers hybrid modes like volume-assured pressure support and pressure regulated volume control (PRVC) which use dual controls. Newer dual-controlled modes are presented that regulate pressure and volume both within and between breaths. Modes like adaptive support ventilation (ASV) automatically adapt settings to patient changes. Pros, cons and indications are provided for some of the more complex modes.
1. Functional residual capacity (FRC) is the amount of air in the lungs after a normal expiration and is dependent on factors like sex, age, height, and weight. FRC increases with age and decreases with weight.
2. Positive end-expiratory pressure (PEEP) maintains a positive pressure during expiration to keep alveoli inflated, which increases functional residual capacity and improves oxygenation. PEEP is indicated for refractory hypoxemia, intrapulmonary shunts, and decreased FRC and lung compliance.
3. Complications of PEEP include decreased venous return, decreased cardiac output, barotrauma, increased intracranial pressure, and altered renal function
APRV (Airway Pressure Release Ventilation) is a ventilation mode that applies continuous positive airway pressure (CPAP) for a prolonged high-pressure phase (T high) to recruit and maintain lung volume. It then has a brief low-pressure release phase (T low) where most ventilation and CO2 removal occurs. Compared to conventional ventilation, APRV may cause less ventilator-induced lung injury due to maintaining higher end-expiratory lung volumes without repetitive opening/closing of alveoli. It also allows for spontaneous breathing which improves patient comfort and outcomes. While APRV does not reduce mortality, it can improve other outcomes such as shorter ventilation times and ICU stays.
Mechanical ventilation is a therapeutic method that uses physical devices to assist or replace spontaneous breathing. There are two main types: negative pressure ventilation which applies pressure lower than atmospheric to the chest, and positive pressure ventilation which applies pressure higher than atmospheric to the lungs. Positive pressure ventilation is more commonly used today. It is important to carefully monitor patients on mechanical ventilation to optimize ventilation and prevent lung injury, through monitoring pressures, volumes, oxygen levels and CO2 levels. The goals are to provide adequate gas exchange while applying the lowest possible pressures and volumes to the lungs.
Rapid sequence induction and intubation (RSII) is a technique used to minimize the risk of pulmonary aspiration by rapidly inducing unconsciousness and paralysis before intubating the trachea. Key elements of RSII include pre-oxygenating the patient, administering sedative and neuromuscular blocking agents to quickly induce unconsciousness and paralysis, applying cricoid pressure, and promptly intubating the trachea with minimal ventilation. Indications for RSII include patients with full stomachs or gastrointestinal pathology who are at higher risk of aspiration. Contraindications include total airway obstruction or loss of airway landmarks. Potential complications include difficult or failed airway, hypoxia, hypotension,
1) ARDS is characterized by hypoxemia, bilateral lung infiltrates, and respiratory failure not fully explained by cardiac failure. The Berlin definition classifies ARDS as mild, moderate, or severe based on oxygenation levels.
2) Management of ARDS focuses on treating underlying causes, preventing complications, and using ventilator strategies like low tidal volume ventilation to prevent ventilator-induced lung injury.
3) Other ventilator strategies discussed include prone positioning, neuromuscular blockade, recruitment maneuvers, and extracorporeal membrane oxygenation for severe cases, though evidence on benefits is mixed.
New modes of mechanical ventilation TRCchandra talur
The document discusses newer modes of mechanical ventilation that were introduced to address clinical issues like poor patient-ventilator synchrony, prolonged weaning times, and ventilator-induced lung injury. It classifies the newer modes as dual modes that combine volume and pressure control, modes that adapt to lung characteristics, and knowledge-based weaning modes. It provides more details on proportional assist ventilation (PAV+), airway pressure release ventilation (APRV/BIPAP), and Smartcare—modes that aim to improve synchrony, maintain high functional residual capacity, and reduce workload for clinicians respectively.
This document provides an overview of mechanical ventilation, including its history, types of ventilators, modes of ventilation, and indications for use. It begins with a definition of mechanical ventilation and descriptions of negative pressure and positive pressure machines. It then covers various modes of ventilation including volume-targeted modes, pressure-regulated modes, and modes based on breath initiation such as assist-control, SIMV, and pressure support. The document concludes with a section on indications for mechanical ventilation and complications that can arise.
Sam ppt on effect of anaesthesia on respiratory systemRanjana Meena
The document discusses how anaesthesia can impair the respiratory system by decreasing functional residual capacity and compliance, reducing the respiratory drive and increasing atelectasis and ventilation-perfusion mismatch. It outlines the effects of various anaesthetic agents on ventilation and gas exchange and provides strategies to manage these impacts, such as positioning, recruitment manoeuvres, positive end-expiratory pressure and postoperative oxygen therapy.
Evolutionary development and anatomy of the lungsmeducationdotnet
- Early fish developed swim bladders that evolved into primitive lungs, allowing amphibians to survive out of water.
- In human embryos, lung buds develop from the gut tube and form the inner and outer pleura, allowing lung expansion and contraction.
- The trachea connects the lungs to the initial gut tube and is supported by cartilage rings for flexibility and preventing collapse.
MECHANICAL VENTILATION-SOME OF THE BASICS.pptxAjilAntony10
This document discusses mechanical ventilation, including its history, uses, types, settings, modes, complications, and patient care goals. It provides an overview of mechanical ventilation, describing how it works to mechanically assist or replace spontaneous breathing. Various modes of ventilation are outlined, along with typical settings adjusted based on patient status. Potential complications are listed. Patient goals focus on effective breathing, gas exchange, nutrition, preventing infection or immobility issues. Care includes airway management and monitoring respiratory rate and depth.
Respiratory failure occurs when the lungs cannot effectively exchange oxygen and carbon dioxide, resulting in hypoxemia (low blood oxygen) and hypercapnia (high blood carbon dioxide). Acute respiratory failure develops suddenly in patients without preexisting lung disease, while chronic respiratory failure is caused by conditions like COPD. Treatment involves oxygen therapy, ventilation if needed, treating the underlying cause, and monitoring vital signs.
Noninvasive ventilation (NIV) refers to ventilatory support without an invasive artificial airway such as an endotracheal or tracheostomy tube. NIV can be delivered via nasal or oronasal masks connected to positive pressure ventilators. The document traces the history of ventilation from ancient times to modern NIV techniques. It describes various interfaces, modes of ventilation including CPAP, contraindications, and suitable clinical conditions for NIV support such as COPD exacerbations and cardiac pulmonary edema.
This document discusses pediatric ventilation basics including anatomy, physiology, pathophysiology, and terminology. Key points include: the pediatric airway is smaller and more anteriorly placed; children have higher oxygen needs and lower tolerance for hypoxia; compliance is lower in children; and ventilator settings like tidal volume, rate, inspiratory time, and PEEP must be adjusted for pediatric patients. Common pediatric lung conditions and how they impact pulmonary function tests and the ventilation/perfusion ratio are also reviewed.
Anatomically the respiratory system is divided into
Upper respiratory tract
From the nostril to the vocal cord
Lower respiratory tract
The lower respiratory tract is from bellow the vocal cord upto the alveoli
The document discusses mechanical ventilation in the ICU. It begins with an introduction covering the history and advancements of mechanical ventilation. It then discusses the main indications for mechanical ventilation, which include ventilatory failure and oxygenation failure. Ventilatory failure is defined as the inability to remove adequate carbon dioxide and can be caused by various mechanisms like hypoventilation. Oxygenation failure refers to hypoxemia not responsive to oxygen supplementation and is caused by more severe mechanisms. The document outlines some clinical conditions that warrant mechanical ventilation like respiratory failure, impending respiratory failure, and low output states. It also discusses the basics of mechanical ventilators including phase variables, control variables, and the main modes of volume control and pressure control ventilation.
This is the introduction to airway management for Advanced EMTs though some medics might find it useful too. Focuses mainly on supraglottic and periglottic airway devices as well as basic anatomy , physiology, etc. Talks about apniec defusion too.
MECHANICAL VENTILATION - A BRIEF DISCUSSION.pptxAjilAntony10
This document discusses mechanical ventilation, including its history, uses, types, settings, modes of ventilation, complications, and patient goals and care. It provides an overview of mechanical ventilation, from its use in acute and chronic illness to manage breathing, to different ventilator modes like CMV, ACV, SIMV and PSV. It also covers settings, interfaces, potential complications and how to monitor patients on ventilators.
The document provides information on ventilators including their history, parts, types, modes of operation, and physiotherapy management of ventilated patients. It describes how ventilators mechanically breathe for patients unable to do so themselves and discusses various types like transport, ICU, neonatal, and high frequency ventilators. Key points covered include indications for ventilation, settings, weaning process, complications, advantages, and physiotherapy techniques to prevent issues in ventilated patients like early mobilization and airway clearance.
The must to know facts about ventilator. Indeed a detailed information can be gathered from the presentation. This presentation includes definition, history, terminology, need of ventilation,indication, types, complications, etc.
This document discusses mechanical ventilation and provides guidelines on its use. It begins with definitions of hypoxemia and hypercarbia and their clinical indications. It then lists various indications for mechanical ventilation related to oxygen delivery and consumption imbalance, increased work of breathing, inspiratory muscle weakness, and heart failure. The document discusses the history of mechanical ventilation and some basic concepts including pressures, volumes, flows, compliance and resistance. It provides details on ventilator circuits, triggers, and phases of mechanical ventilation.
Mechanical ventilation involves using a machine to assist or replace spontaneous breathing. It is commonly used in ICUs for patients with acute respiratory failure or distress. Some key points:
- There are two main types - negative pressure ventilation uses suction to pull air into the lungs, while positive pressure ventilation pushes air into the lungs.
- Indications for use include respiratory acidosis, hypoxemia, increased work of breathing, and neurological/pulmonary conditions.
- Common modes include controlled mandatory ventilation (CMV), assisted-control (AC), and synchronized intermittent mandatory ventilation (SIMV).
- Settings are based on parameters like respiratory rate, tidal volume, oxygen concentration, and pressures.
Acute respiratory distress syndrome (ARDS) occurs when fluid leaks into the alveolar sacs, causing them to fill and collapse. This prevents proper gas exchange and leads to hypoxemia and potentially organ dysfunction. ARDS develops suddenly and commonly affects hospitalized patients with preexisting conditions due to direct lung injury or indirect systemic inflammation. It progresses through exudative, proliferative, and fibrotic phases, causing increased stiffness and damage to lung tissue over time. Treatment focuses on mechanical ventilation with PEEP to reinflate lungs and prevent further collapse, as well as managing complications. The goal is to improve oxygen levels and prevent additional organ problems.
Oxygen insufficiency refers to an inadequate supply of oxygen to tissues in the body. It can be caused by factors that decrease oxygen delivery or utilization. Common types include hypoxemic hypoxia from low oxygen in the blood, circulatory hypoxia from poor blood flow, anemic hypoxia from low hemoglobin, and histotoxic hypoxia interfering with cellular oxygen use. Symptoms include shortness of breath, clubbing of fingers, and cognitive impairments. Treatment focuses on identifying and addressing the underlying cause, administering supplemental oxygen, and mechanical ventilation for severe cases. Nurses monitor patients' respiratory status and the ventilator to optimize oxygenation.
Similar to Weaning from mechanical Ventilation (20)
This document discusses cardiogenic shock. It begins by defining cardiogenic shock as a life-threatening condition caused by primary cardiac dysfunction resulting in inadequate cardiac output and tissue hypoperfusion. Acute myocardial infarction is identified as the most common cause, accounting for around 80% of cases. The document outlines the clinical presentation of cardiogenic shock, which can include signs of hypotension, altered mental status, and cold, clammy skin. Investigations like echocardiogram, blood work and electrocardiogram are recommended to assess cardiac function and identify the cause, while cardiac catheterization is the definitive diagnostic test and guides treatment.
ACUTE RESPIRATORY DISTRESS SYNDROME (ARDS) .BY DR.Mohammad Abdeljawad Mohammad Abdeljawad
Acute respiratory distress syndrome (ARDS) is an acute lung injury characterized by increased pulmonary vascular permeability and loss of aerated lung tissue. It can be caused by sepsis, pneumonia, or other clinical insults. The Berlin definition classifies ARDS as mild, moderate, or severe based on hypoxemia levels. A diagnosis of ARDS requires onset within one week of a known clinical insult and bilateral opacities on chest imaging. While invasive tests provide limited utility, bronchoscopy and bronchoalveolar lavage may be used to diagnose atypical cases or rule out other conditions.
The document discusses carbon dioxide absorbers and soda lime, which are used to absorb carbon dioxide exhaled by patients during anesthesia. It provides details on:
- How soda lime chemically absorbs carbon dioxide through a neutralization reaction, forming carbonates, water, and heat.
- The components and function of the canister containing the soda lime granules.
- Factors that influence the efficiency of carbon dioxide absorption, such as granule size and minimizing channeling of gases.
- Signs that the soda lime is exhausted and needs to be replaced, including color change of indicator dyes and increased end-tidal carbon dioxide.
Anesthestic Breathing Systems by Dr. Mohammad abdeljawad Mohammad Abdeljawad
The document discusses various types of anesthetic breathing systems and Mapleson circuits. It provides properties of an ideal breathing system and classifies systems as rebreathing systems with CO2 absorption, non-rebreathing systems, and systems without a gas reservoir. Details are given on components of Mapleson circuits like breathing tubes, the fresh gas inlet, adjustable pressure-limiting valve, and reservoir bag. The mechanisms and efficiencies of different Mapleson circuits (A, B, C, D, E, F) are explained. High fresh gas flows are required to reduce CO2 rebreathing without valves or an absorber.
Dr. Mohammad Abdeljawad discusses fluid flow through tubes. He defines flow as the quantity of fluid passing a point over time. Flow can occur through tubes of constant or variable diameter, or an orifice. In tubes of constant diameter, laminar flow is steady without eddies, while turbulent flow is irregular with eddies above a critical velocity. Factors like radius, length, and viscosity affect laminar flow and resistance according to the Hagen-Poiseuille equation. In tubes of variable diameter, the Bernoulli effect causes pressure and velocity changes. Clinical applications include increasing flow rates and managing asthma and respiratory resistance.
An anesthetic machine consists of several key components:
1. Medical gas supplies from cylinders or central pipelines
2. Pressure regulators to reduce gas pressures
3. Flowmeters to deliver known gas flows
4. Vaporizers to convert liquid anesthetics to vapor
5. Breathing circuits to deliver gases to patients
The document then provides further details on each component and how the overall anesthesia delivery system functions.
The document discusses coronavirus disease (COVID-19) including its definition, transmission, clinical presentation, course, and diagnostic testing recommendations. It defines healthcare personnel and notes COVID-19 is a new coronavirus strain discovered in 2019 that is zoonotic, mainly spread through respiratory droplets. Symptoms can range from mild to severe and include fever, cough and shortness of breath. Older patients and those with chronic conditions are at higher risk. Diagnostic testing is recommended for suspected cases using molecular tests on respiratory specimens.
The document discusses coagulation and disseminated intravascular coagulation (DIC). It begins by explaining the three stages of hemostasis: vascular spasm, primary hemostasis involving platelet plug formation, and secondary hemostasis involving fibrin strand formation. It then details the coagulation cascade and its four phases: initiation, amplification, propagation, and clot stabilization. The document concludes by covering the causes, mechanisms, clinical manifestations, diagnosis, differential diagnosis, and treatment of DIC.
The document provides information on the anatomy, physiology, and pathology of pancreatitis. It begins with a description of the pancreas' location and structure, including its head, neck, body, and tail. It then discusses the exocrine and endocrine functions of the pancreas. Regarding pancreatitis, it notes that it is defined as pancreatic inflammation caused by injury to the exocrine pancreas. The document outlines the epidemiology, classification, etiology, pathophysiology, signs and symptoms, diagnostic criteria involving serum markers, and differential diagnosis of acute pancreatitis.
1. Gases obey Boyle's law, Charles' law, and Gay-Lussac's law, collectively known as the gas laws.
2. The ideal gas law combines these and states that for an ideal gas, pressure × volume divided by temperature is a constant (PV/T = nRT).
3. Dalton's law of partial pressures states that in a gas mixture, the total pressure is equal to the sum of the partial pressures of the individual gases.
1. Gases obey Boyle's law, Charles' law, and Gay-Lussac's law, collectively known as the gas laws.
2. The ideal gas law combines these and states that for an ideal gas, pressure × volume divided by temperature is a constant (PV/T = nRT).
3. Dalton's law of partial pressures states that in a gas mixture, the total pressure is equal to the sum of the partial pressures of the individual gases.
Integrating Ayurveda into Parkinson’s Management: A Holistic ApproachAyurveda ForAll
Explore the benefits of combining Ayurveda with conventional Parkinson's treatments. Learn how a holistic approach can manage symptoms, enhance well-being, and balance body energies. Discover the steps to safely integrate Ayurvedic practices into your Parkinson’s care plan, including expert guidance on diet, herbal remedies, and lifestyle modifications.
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Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...Oleg Kshivets
Overall life span (LS) was 1671.7±1721.6 days and cumulative 5YS reached 62.4%, 10 years – 50.4%, 20 years – 44.6%. 94 LCP lived more than 5 years without cancer (LS=2958.6±1723.6 days), 22 – more than 10 years (LS=5571±1841.8 days). 67 LCP died because of LC (LS=471.9±344 days). AT significantly improved 5YS (68% vs. 53.7%) (P=0.028 by log-rank test). Cox modeling displayed that 5YS of LCP significantly depended on: N0-N12, T3-4, blood cell circuit, cell ratio factors (ratio between cancer cells-CC and blood cells subpopulations), LC cell dynamics, recalcification time, heparin tolerance, prothrombin index, protein, AT, procedure type (P=0.000-0.031). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and N0-12 (rank=1), thrombocytes/CC (rank=2), segmented neutrophils/CC (3), eosinophils/CC (4), erythrocytes/CC (5), healthy cells/CC (6), lymphocytes/CC (7), stick neutrophils/CC (8), leucocytes/CC (9), monocytes/CC (10). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; area under ROC curve=1.0).
Cell Therapy Expansion and Challenges in Autoimmune DiseaseHealth Advances
There is increasing confidence that cell therapies will soon play a role in the treatment of autoimmune disorders, but the extent of this impact remains to be seen. Early readouts on autologous CAR-Ts in lupus are encouraging, but manufacturing and cost limitations are likely to restrict access to highly refractory patients. Allogeneic CAR-Ts have the potential to broaden access to earlier lines of treatment due to their inherent cost benefits, however they will need to demonstrate comparable or improved efficacy to established modalities.
In addition to infrastructure and capacity constraints, CAR-Ts face a very different risk-benefit dynamic in autoimmune compared to oncology, highlighting the need for tolerable therapies with low adverse event risk. CAR-NK and Treg-based therapies are also being developed in certain autoimmune disorders and may demonstrate favorable safety profiles. Several novel non-cell therapies such as bispecific antibodies, nanobodies, and RNAi drugs, may also offer future alternative competitive solutions with variable value propositions.
Widespread adoption of cell therapies will not only require strong efficacy and safety data, but also adapted pricing and access strategies. At oncology-based price points, CAR-Ts are unlikely to achieve broad market access in autoimmune disorders, with eligible patient populations that are potentially orders of magnitude greater than the number of currently addressable cancer patients. Developers have made strides towards reducing cell therapy COGS while improving manufacturing efficiency, but payors will inevitably restrict access until more sustainable pricing is achieved.
Despite these headwinds, industry leaders and investors remain confident that cell therapies are poised to address significant unmet need in patients suffering from autoimmune disorders. However, the extent of this impact on the treatment landscape remains to be seen, as the industry rapidly approaches an inflection point.
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
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share - Lions, tigers, AI and health misinformation, oh my!.pptxTina Purnat
• Pitfalls and pivots needed to use AI effectively in public health
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Histololgy of Female Reproductive System.pptxAyeshaZaid1
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
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Basavarajeeyam is a Sreshta Sangraha grantha (Compiled book ), written by Neelkanta kotturu Basavaraja Virachita. It contains 25 Prakaranas, First 24 Chapters related to Rogas& 25th to Rasadravyas.
3. Hippocrates
As early as in the fifth
century bc , Hippocrates,
described a
technique for the prevention
of asphyxiation. In his work,
“Treatise on Air,”
Hippocrates stated, “One
should introduce
a cannula into the trachea
along the jawbone so that air
can be
drawn into the lungs.”
Hippocrates thus provided
the first
description of endotracheal
intubation (ET).
3
4. Paracelsus
The first form of
mechanical ventilator can
probably be
credited to Paracelsus, who
in 1530 used fire-bellows
fitted
with a tube to pump air
into the patient’s mouth.
ديسمبر1493سويسرا–توفي
في24سبتمبر1541فيزالتسبوغ
النمسا
4
5. Andreas Vesalius
In 1653,
Andreas Vesalius recognized that
artificial respiration could
be administered by
tracheotomising a dog.24 In his
classic,
“De Humani Corporis Fabricia,”
Vesalius stated, “But that
life may … be restored to the
animal, an opening must be
attempted in the trunk of the
trachea, in which a tube of reed
or cane should be put; you will
then blow into this so that the
lung may rise again and the animal
take in air… And also as
I do this, and take care that the
lung is inflated in intervals,
the motion of the heart and
arteries does not stop….”
فيزاليوس أندرياسعالم هووطبيب تشريح
جراحفلمنكي(بلجيكي( )31ديسمبر1514-
5
6. Robert Hooke
A hundred years later, Robert Hooke
duplicated Vesalius’
experiments on dog, and while
insufflating
air into an opening made into the
animal’s trachea, observed
that “the dog… capable of being kept
alive by the reciprocal
blowing up of his lungs with Bellows,
and they suffered to
subside, for the space of an hour or more,
after his Thorax had
been so displayed, and his Aspera arteria
cut off just below the
Epiglottis and bound upon the nose of
the Bellows.”11 Hooke
also made the important observation
that it was not merely the regular
movement of the thorax that prevented
asphyxia,
but the maintenance of
phasic airflow into the
lungs
هوك روبرت(18يوليو1635وفق ،التقويمالقديم-3
مارس1703)فيلسوفوعالم ومعماري طبيعي
إنجليزي موسوعي
6
7. John Fothergill
What was possibly the
first successful instance
of human resuscitation
by mouth-to-mouth
breathing was described
in 1744 by John
Fothergill in England.
1712-1720بريطانيا فوثرجيل جون
7
8. Royal Humane Society
“Society for the
Rescue of Drowned
Persons”
The use of bellows to resuscitate
victims of near-drowning
was described by the Royal Humane
Society in the eighteenth
century.20 The society, also known as
the “Society for
the Rescue of Drowned Persons” was
constituted in 1767, but
the development of fatal
pneumothoraces produced by
vigorous
attempts at resuscitation led to
subsequent abandonment
of such techniques. John Hunter’s
innovative double-bellows
system (one bellow for blowing in
fresh air, and another for
drawing out the contaminated air)
was adapted by the Society
in 1782, and introduced a new concept
into ventilatory care
8
9. William Macewen
In 1880, William Macewen was the
first to describe and to perform
that technique. In his paper
entitled "clinical observations on
the introduction of tracheal tubes
by the mouth instead of
performing tracheotomy or
laryngotomy' he describes in
addition two cases of endotracheal
intubation lasting at least 36 h. He
can, therefore, be said also to have
performed the first long-time
intubation.
(مواليد22يونيو1848فياسكتلندا-الوفاة
22مارس1924فيغالسكو)،
هوجراحاسكتلنديمجالجراحة في ًارائد كان
الدماغ الحديثةجراحة تطوير في وساهم
العظامبالترقيع . والعالج
الجراحيللفتق , واستئصالالرئة(إزالة
الرئتين.)
9
10. Appreciation of the fact
that life could be sustained by
supporting the function of the
lungs (and indeed the circulation)
by external means led to
the development of machines
devised for this purpose.
- In 1838, Scottish physician John
Dalziez described the first tank
ventilator.
-In 1864 a body-tank ventilator was
developed by Alfred Jones of
Kentucky.
10
11. the iron lung
-In 1929, Philip Drinker, Louis
Shaw, and Charles McKhann saw
the
development of what was dubbed
“the iron lung.
11
13. positive-pressure
mechanical ventilation
Intensive use of positive-pressure
mechanical ventilation gained
momentum during the polio epidemic in
Scandinavia and the United States in the
early 1950s. In Copenhagen, the patient
with polio and respiratory paralysis who
was supported by manually forcing 50%
oxygen through a tracheostomy had a
reduced mortality rate.
However, this heroic intervention
required the continuous activity of 1400
medical students recruited from the
universities. The overwhelming
manpower needed, coupled with a
decrease in mortality rate from 80% to
25%, led to the adaptation of the
positive-pressure machines used in the
operating room for use in the ICU.
Positive-pressure ventilation means that
airway pressure is applied at the patient's
airway through an endotracheal or
tracheostomy tube. The positive nature
of the pressure causes the gas to flow
into the lungs until the ventilator breath
is terminated. As the airway pressure
drops to zero, elastic recoil of the chest
accomplishes passive exhalation by
pushing the tidal volume out.
13
15. A-To Maintain Adequate Oxygenation
(Sao2<95%) with a Fio2 >0.5
(Hypoxia)
Mechanical ventilation is often electively instituted when it is
not possible to maintain an adequate oxygen saturation of
hemoglobin
Arterial oxygenation is controlled by one of the following
mechanisms:
1- Fi02: Initially it is adjusted at 40% (may be at 50% in severe
hypoxic patients). Avoid higher concentrations > 50-60% to
avoid the risk of 02 toxicity. Then after 10 min, arterial blood
gases are repeated to readjust the FiOi.
2- Positive end-expiratory pressure (PEEP).
3- Inverse ratio ventilation (IRV).
4- Pressure Support.
In addition to the prone ventilation and inhaled nitric oxide that
are used to improve oxygenation.
15
16. B-To Maintain he PaCo2 at Satisfactory level
(Hypoventilation)
A major indication for mechanical ventilation is when
the alveolar ventilation falls short of the patient’s
requirements.
Conditions that depress the respiratory center produce
a decline in alveolar ventilation with a rise in arterial
CO2 tension.
A rising PaCO2 can also result from the
hypoventilation that results when fatiguing respiratory
muscles are unable to sustain ventilation, as in a
patient who is expending considerable effort in
moving air into stiffened or obstructed lungs.
16
17. Under such circumstances, mechanical ventilation
may be used to support gas exchange until the
patient’s respiratory drive has been restored, or tired
respiratory muscles rejuvenated, and the inciting
pathology significantly resolved
17
19. -The aim is to produce gradual changes in the PaC02 until an
adequate satisfactory level is reached. C02 tension is controlled
by:
1- The dead space: A reduction of dead space such as cutting of
the endotracheal tube or the use of a tracheostomy tube
decreases the PaC02.
2- The minute ventilation= respiratory rate x tidal volume.
Increasing the tidal volume usually decreases the PaC02 more
than increasing the respiratory rate. The latter may also cause
respiratory alkalosis.
-CO2 tension should be adjusted as follows:
• In patients with a normal PaC02 before mechanical ventilation,
minute ventilation should be adjusted to produce a PaCO2
between 30-35 mm Hg.
19
20. • In patients with an initial high PaC02 before mechanical
ventilation, the PaC02 should be reduced at a rate < 7.6
mm Hg (lkpa(/hour, because rapid reduction produces a
marked fall in the cardiac output and arterial blood
pressure.
• In patients with an initial chronically high PaC02 (e.g.,
chronic bronchitis), the PaC02 should be reduced at the
same rate and should not be reduced below 40-45 mm Hg.
• In patients with a low PaC02 < 30 mm Hg before
mechanical ventilation, minute ventilation should be
adjusted to increase the PaC02 slowly by controlling the
respiratory rate. Further adjustment should be done after
one hour.
20
21. C-To Decrease the Work of
Breathing
Another major category where assisted ventilation is used
is in those situations in which excessive work of breathing
results in hemodynamic compromise. Here, even though
gas exchange may not be actually impaired, the increased
work of breathing because of either high airway resistance
or poor lung compliance may impose a substantial burden
on, for example, a compromised myocardium
When oxygen delivery to the tissues is compromised on
account of impaired myocardial function, mechanical
ventilation by resting the respiratory muscles can reduce
the work of breathing. This reduces the oxygen
consumption of the respiratory muscles and results in
better perfusion of the myocardium itself
21
22. The work of breathing can be reduced by:
1- Increasing Vt and respiratory rate.
2- Increasing inspiratory flow rate (IFR).
3- Trying pressure support ventilation.
4- Using flow triggering.
5-In addition to:
• Decreasing pain, anxiety, and discomfort.
• Decreasing C02 production e.g., reducing carbohydrate
diets.
• Using sedation and paralysis.
• Reassurance.
22
24. IndicIndicaIndicationstionsations
Indications for intubation Indications for ventilation
Need to secure airway Hypoxia: acute hypoxemic
respiratory failure
Depressed sensorium Hypoventilation
Depressed airway reflexes Unacceptably high work of
breathing
Upper airway instability after
trauma
Hemodynamic compromise
Decreased airway patency Cardiorespiratory arrest
Need for sedation in the
setting of poor airway control
Raised intracranial pressure
Imaging (CT, MRT) and
transportation of an unstable patient
Flail chest
24
26. Criteria for Intubation and
Ventilation
The most important is the clinical judgment
. The following criteria are guide:
1- Respiratory Gas Tension:
a- Direct Indices:
• Pa02 < 50 mm Hg in room air or Pa02 < 60 mm Hg with FI02 > 50%.
• PaCO2 > 55 mm Hg in absence of chronic hypercarbia or metabolic
alkalosis i.e., pH is < 7.25 (would likewise imply the onset of respiratory
muscle fatigue.)
. b- Derived Indices:
• Pa02f FI02 ratio < 200.
• Alveolar- arterial 02 tension gradient (PA-a02gradient) > 300 mm Hg
with FI02 1.0.
Dead space/tidal volume (Vd/Vt) >0.6
. • Shunt equation (Qs/Qt) > 20%
26
27. 2- Clinical Indices:
• Respiratory rate > 35 breath/ min (unacceptably high work of
breathing and a substantial degree of respiratory distress.)
• Respiratory muscle paradox.
3- Mechanical Indices:
• Tidal volume < 5 mL/kg.
• Vital capacity< 10-15 mL/kg.
• Maximum inspiratory force> - 25 cm H20. i.e., - 20 or -15 ... etc.
• Rapid shallow breathing index (respiratory rate/Vt)> 200
breaths/min/L.
• Minute ventilation < 4 L/ min or > 10 L/ min
27
28. a forced expiratory volume in the first second (FEV1) of
less than 10 mL/kg
forced vital capacity (FVC) of less than 15 mL/kg body
weight (both of which indicate a poor ventilatory
capability.)
28
29. It is important to emphasize that the criteria for
intubation and ventilation are meant to serve as a
guide to the physician who must view them in the
context of the clinical situation
Conversely, the patient does not necessarily have to
satisfy every criterion for intubation and ventilation in
order to be a candidate for invasive ventilatory
management
29
33. The ease of weaning a patient from a ventilator is
generally inversely related to the duration of the
mechanical ventilation
Weaning should be considered as soon as the patient
has recovered sufficiently from his illness to be able to
endure the responsibility of sustained spontaneous
breathing
The condition for which the patient was ventilated
should have improved significantly, although
incomplete resolution does not preclude successful
weaning
33
34. Criteria of Successful Weaning:
Before weaning, the following criteria should be considered:
1- The process that necessitated mechanical ventilation must be reversed or under
control before weaning is attempted i.e., patients no longer meet indications
for mechanical ventilation and must have the following criteria
- criteria for prediction of outcome
- . a- Respiratory Gas Tension:
- • Direct Indices:
- PaOi > 60 mm Hg (or SaOi > 90%) with FIOi < 0.5 with< 5 cm H20 PEEP.
- PaC02 < 50 mm Hg except if the patient has chronic hypercarbia.
- • Derived Indices:
- PaOi/Fi02 ratio > 200 mm Hg
- . Alveolar-arterial 02 tension gradient (PA- a Oagradient) < 300-350 mm Hg at
FIOi 1.0 or < 200 mm Hg at FIOi 0.5.
- Dead space/tidal volume ratio (Vd/Vt) < 0.6.
- Shunt equation Qs/Qr < 15%
34
35. b- Respiratory Rate: < 30-35 breath/ min in adults.
Both the arterial blood gases and respiratory rate are the
most useful criteria.
c- Respiratory Mechanics:
-Tidal volume> 5 mL/kg.
- Vital capacity > 10 mL/kg.
- Minute ventilation 4-10 L/min.
35
36. Maximum inspiratory pressure (force) < - 15 to -30 cm
HzO i.e., -35, -40 ... etc is considered the threshold for
weaning. This can be detected by allowing the patient
to exhale to residual lung volume and then inhale as
forcefully as possible against a closed valve. Healthy
adults can generate a pressure of -90 to -120 cm HzO
36
37. Rapid shallow breathing index=Respitory
rate(beath/min)/tidal volume(L)
-Its normal value is 40-50 breath/ min/ L.
- If it is< 100 breath/min/L, this indicates weaning
success.
- If it is> 100 breath/min/L, this indicates weaning
failure.
Work of breathing: It is defined as the 02
consumption of the respiratory muscles calculated
from the metabolic gas monitor. If it is< 1.6 kg.m/min,
it indicates successful weaning.
37
38. 2- Correction of reversible factors that may complicate
weaning such as:
• Bronchospasm. • Malnutrition. • Anemia.
• Infection. • Acid-base disturbances. • Sleep
deprivation.
• Increased C02 production (high carbohydrate).
• Hypothermia or hyperthermia
38
39. 3- Good status of other systems such as:
• Glasgow coma scale should be more than 13. The patient should
be alert and conscious.
• Gag and cough reflexes should be intact.
• Hemodynamic stability should be present with minimal or no
vasopressor support except in postsurgical cardiac patients that
can be weaned in spite of high vasopressor support because the
effect of cardiopulmonary bypass and peripheral vasodilatation
usually resolve quickly.
• Underlying lung disease and respiratory muscle wasting should
be absent
39
40. General Precautions during
Weaning:
• The sedation level should be reduced.
• The FI02 is usually y 0.4 to allow successful weaning.
• Continuous pulse oximetry.
• Arterial blood gases should be checked every 20-30 min.
• In the early stages of weaning, mechanical ventilation is often
continued at night to encourage sleep, avoid fatigue, and rest
respiratory muscles.
• After short-term ventilation (< 1week), if arterial blood gases,
respiratory pattern, and cough reflex are satisfactory, the patient can be
extubated.
• After long-term ventilation (> 1week), the patient should generally be
allowed to breathe spontaneously for at least 24 hours before
extubation.
40
41. Techniques of Weaning:
Weaning can be through a ventilator or through a T-
piece. There is no evidence that any method is
superior to others for allowing weaning from
mechanical ventilation permanently
41
42. A-Through a Ventilator
1-Synchronized lnterrnittent lJnd.itory
Ventilation (SIMVJ:
• The number of mechanical breaths is progressively decreased by
1-2 breath/min as long as the PaC02 and spontaneous respiratory
rate remain acceptable i.e., < 45 mm Hg and < 30 breath/ min
respectively, allowing the patient to slowly take over spontaneous
ventilation. When SIMV of 1-2 breaths/min is reached,
mechanical ventilation is discontinued.
• It is the least efficient mode of weaning because it promotes
dependence on the ventilator and can be confusing to the
respiratory center.
42
43. • In patients with acid-base disturbances or chronic C02
retention, arterial blood pH (> 7.35) is more useful
than C02 tension monitoring. Blood gas
measurements should be checked after a minimum of
10-20minutes at each setting.
• If pressure support is concomitantly used with SIMV.it
should be reduced
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44. 2-Pressure Support Ventilation
(PSV)
• The PS level should be decreased by 2-3cm H20 (with the
same criteria of PaC02 and respiratory rate as with
SIMV).When a PSlevel of< 5-8cm H20 is reached, the
patient can be extubated.
- A PaO2 < 60mm Hg or a Sa02 < 90%require a return to
previous levels of respiratory support.
- A PaO2 of 60-70mm Hg or a Sa02 of 90%require a hold at
the current level of respiratory support. a A PaO2> 70mm
Hg or a Sa02 > 92%allow progression to weaning.
• It can be combined with SIMVor with CPAP.
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45. 3-Continuous Positive Airway
Pressure
(CPAP)
• Low levels of CPAP (5 cm H20) while the patient
breathes spontaneously (instead of the T-piece)
because:
- It maintains the functional residual capacity (FRC).
-It prevents basal atelectasis which can occur during
prolonged T- piece trials due lo absence of a nor-mal
physiologic PEEP when the larynx is bypassed by an
endotracheal tube
The patient is also observed clinically for signs of
fatigue and respiratory distress and arterial blood
gases are done as with the T-piece.
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48. Device:
AT-piece is a T-shaped circuit that is attached to the endotracheal
tube or tracheostomy tube.
It has corrugated tubing on the other two limbs.
The inhaled gas is delivered after humidification at a high flow
rate (greater than the patient's inspiratory flow rate) through
one of the upper arms of the apparatus with or without Venturi
arrangement.
The high flow rate serves two purposes:
“1-It creates a suction effect that carries the exhaled gas out of the
apparatus and prevents rebreathing of exhaled gas. “
2- It prevents the patient from inhaling room air from the
exhalation side of the apparatus. The exhaled gas exits through
the other limb of the T-circuit
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49. Technique:
• When the patient meets the criteria for weaning, a T-piece adaptor and
heated nebulizer are connected to the patient's endotracheal tube. The
patient should be in a semi-sitting position. FIOzis set at a level 5-
10%higher than that during mechanical ventilation.
• 3-8 trials/day is performed. In them, allow the patient to breathe
spontaneously without any mechanical breaths. The patient is
observed closely during this period (usually 20-30 min) for signs of
failure of weaning
• If the above criteria of failure of weaning are present, weaning should be
discontinued.
• If the patient has been intubated for a prolonged period, or has a severe
underlying lung disease, Tpiece trials are done in periods of 10-20min
which progressively increase by 5-10minutes/hour until the patient
appears comfortable and shows acceptable arterial blood gases (SaO2>
90%,end-tidal Co2>znormal or constant throughout the trial).
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50. Advantages of T-piece: Less work of breathing is
needed during weaning.
Disadvantages of T-piece: inability to monitor the
patient's spontaneous tidal volume and respiratory
rate.
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51. Sign of Weaning Failure:
• Discoordinate labored spontaneous breathing.
• Exhaustion, agitation, and diaphoresis.
• The respiratory and arterial blood gas values such as
tachypnea (> 30/min), tachycardia(> 100/min),
respiratory acidosis (pH< 7.2),rising PaCOz,and
hypoxemia (SaOi< 90%).
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52. • Abdominal paradox:
Normally, when the diaphragm contracts, it descends into the abdomen
increasing intra-abdominal pressure.
This pushes the anterior wall of the abdomen outward. When the
diaphragm is weak or during labored breathing (i.e., contracting
diaphragm but distressed breathing),
the negative intrathoracic pressure created by accessory muscles of
respiration pulls the diaphragm upward into the thorax during
inspiration because the accessory muscles can overcome the contractile
force of the diaphragm.
This decreases intra-abdominal pressure and causes a paradoxical inward
displacement of the abdomen during inspiration (i.e., abdominal
paradox).
Therefore, abdominal paradox indicates either weak diaphragm or
labored breathing which are signs of failure of weaning.
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