mechanical ventilation in restrictive lung disease.pptx

MECHANICAL VENTILATION IN
RESTRICTIVE PULMONARY
DISEASES
Presenter : Dr Nigat Endalamaw
Advisor : Dr Ayalew Zewude

Out lines of presentation
• Causes of restrictive pulmonary diseases
Lung parenchyma disorders
Interstitial Lung Diseases
Atelectatic disorders
Occupational lung diseases
Pleural disorders
Pleural effusion
Pneumothorax
Extra – pulmonary disorders
Neuro - muscular diseases
Chest wall deformities

Objectives
To able to know pathophysiology of restrictive pulmonary diseases
To able to know clinical presentation of restrictive pulmonary diseases
To able to list some diagnostic modalities of restrictive pulmonary
diseases
To be able to manage restrictive pulmonary diseases
To be able to manage ventilator settings in restrictive pulmonary
diseases

Restrictive pulmonary diseases
• Restrictive pulmonary diseases Result from Decreased Lung Expansion or reduced
lung compliance that requires greater pressure to inflate the lungs due to
pathologies in :
lung parenchyma
Pleura
chest wall
neuromuscular function
• They represent acute or chronic patterns of lung dysfunctions.
• They are Classified as
 Pulmonary
 pleural
Extra - pulmonary

Restrictive pulmonary diseases…….

Restrictive pulmonary diseases……..
• Restrictive pulmonary diseases are characterized by :
Decrease in vital capacity (VC) - total volume of air that can be displaced in or out
from the lungs by maximal inspiratory or expiratory effort = TV + IRV Or Tv + ERV.
 Decrease Total lung capacity (TLC) - is the measured total amount of air that the
lung can hold= ERV + TV + IRV.
Decrease functional residual capacity (FRC) - the volume remaining in the lungs
after a normal, passive exhalation.
Decrease residual volume (RV) - is the volume of air remaining in the lungs after
maximum forceful expiration.
• The greater the decrease in lung volume, greater the severity of disease.
• Their ABG values
Decreased PaO2
Normal or increased PaCO2

1. Lung parenchyma disorders…….
• Interstitial lung disease can be two types :
A - Diffuse Interstitial Lung Disease :
 Pathogenesis is an immune reaction that brings lung tissue infiltration and
Persistent alveolitis leads to obliteration of alveolar capillaries, reorganization of
lung parenchyma resulting in irreversible fibrosis and large air-filled sacs (cysts)
with dilated terminal and respiratory bronchioles.
B - Fibrotic Interstitial Lung Disease :
Pathogenesis fibroblastic proliferation and deposition of large amount of collagen
caused by increased mesenchymal cells and fibroblasts in interstitium then
alveolar walls become thickened with increased amounts of fibrous tissue
 At the end-stage of disease it results destraction and loss of alveolar walls

Clinical manifestations of both are progressive dyspnea with exercise with
desaturation, rapid-shallow breathing ,irritating nonproductive cough and
clubbing of nail beds (40%-80%).
 Bibasilar end-expiratory crackles,cyanosis (late finding),anorexia, weight
loss,inability to increase cardiac output with exercise.
Diagnosis is chest x-ray ,PFT (decreased VC, TLC, diffusing capacity) ,open lung
biopsy,transbronchial biopsy,Gallium-67 scan and bronchoalveolar lavage.
 Treatment is smoking cessation,avoid environmental exposure to cause,anti-
inflammatory agents,immunosuppressive agents and lung transplant.

1. Lung parenchyma disorders……
• B1 - Sarcoidosis
Etiology - Acute or chronic systemic disease of unknown cause.
Immunologic activation of alveolar macrophage to unknown trigger.
Pathogenesis is development of multiple, uniform, noncaseating epithelioid
granulomas.
Affects multiple organs like Lymph nodes, lung tissue (most common),Skin, eyes,
spleen, liver, kidney, bone marrow.
Fibrotic and surrounded by large histiocytes may occur in bronchial airways.
Due to abnormal T-cell function.

 Clinical manifestations are malaise, fatigue,weight loss,fever,dyspnea of
insidious onset,dry, nonproductive cough,erythema nodosum,macules, papules,
hyperpigmentation,subcutaneous nodules,hepatosplenomegaly and
lymphadenopathy.
Diagnosis is leukopenia, anemia,increased eosinophil count,elevated
sedimentation rate,increased Ca++ levels (5%),elevated liver enzymes ,anergy
(70%),elevated angiotensin-converting enzyme in active disease (40%-80%).
 Bronchoalveolar lavage,monitors cell content,fluid has increased lymphocytes
and high CD4/CD8 cell ratio and chest x-ray.
Definitive diagnosis is trans bronchial lung biopsy which shows non caseating
granulomas.

Sarcoidosis chest x-ray stages :
Stage 0 - Normal
Stage 1 - Good prognosis - Hilar adenopathy alone
Stage 2 - Hilar adenopathy and bilateral pulmonary infiltrates
Stage 3 - Pulmonary infiltrates without adenopathy
Stage 4 - Advanced fibrosis with evidence of honeycombing, hilar retraction,
bullae, cysts, and emphysema.
Treatment of sarcoidosis is corticosteroids and immunosuppressive agents.

Sarcodiosis chest x - ray stages

1. Lung parenchyma disorders……..
A1 - Hypersensitivity Pneumonitis or
known as extrinsic allergic alveolitis :
Restrictive and occupational disease
Predominant in nonsmokers (80%-95%)
Pathogenesis is antigen combines with serum antibody in alveolar walls; leads to
type III hypersensitivity reaction then antigen-antibody complexes then elicit
granulomatous inflammation leading to lung tissue injury.
Must have delayed hypersensitivity (type IV) reaction to antigen to develop
pneumonitis.
 Clinical manifestations acute Symptoms start 4-6 hr after exposure and resolve
in 18- 24 hr.
General symptoms chills, sweating, shivering ,myalgias,nausea,malaise, lethargy
and Headache.

Acute respiratory symptoms are dyspnea at rest,dry cough,tachypnea,chest
discomfort.
Physical findings are cyanosis (late) and Crackles in lung bases.
 Intermediate symptoms are acute febrile episodes,progressive pulmonary
fibrosis with cough,dyspnea, fatigue,cor pulmonale.
 Chronic symptoms are progressive, diffuse pulmonary fibrosis in upper lobes
(hallmark of disease).

1. Lung parenchyma disorders…..
• Diagnosis of Hypersensitivity Pneumonitis
Chest x-ray - acute/subacute - transient, bilateral pulmonary infiltrates - increased
bronchial markings with alveolar nodular infiltrates.
Chronic - Diffuse reticulonodular infiltrates and Fibrosis. Laboratory is increased
WBCs .
Others are Skin testing with causative antigen,red, indurated hemorrhagic
reaction 4-12 hr after injection.
 PFTs show decreased lung volumes and diffusing capacity.
• Treatment hypersensitivity pneumonitis
Treatment is identifying offending agent and prevent further exposure.
Oral corticosteroids.

B2 . Occupational Lung Diseases :
Etiology - result from inhalation of toxic gases or foreign particles and
atmospheric pollutants have large effect on occupational respiratory
diseases.
Pneumoconiosis - caused by inhalation of inorganic dust particles and
greater the exposure, the worse the consequences.
Anthracosis - “Coal miner’s lung” or “black lung” .
Silicosis - Silica inhalation.
Asbestosis - Asbestos inhalation

• Predisposing factors for occupational lung disease :
 Preexisting lung disease
Exposure to atmospheric pollutants
Duration of dust exposure
Amount of dust concentration
Particle size of pollutant
• Pathogenesis - Pollutants interfere and paralyze cilia - interference with ciliary
action - impaired clearance effect - Inability to remove the particle.
 Alveolar macrophages try to engulf and remove the particle - Macrophages
secrete lysozymes to control foreign particle activity - Enzymes damage alveolar
walls causing deposition of fibrous materials.

• Clinical manifestations
Symptoms depend on predisposing factor
Pneumoconiosis - produces no signs or symptoms in early stage Usually symptom
free up to 10-20 years with chronic exposure.
Late clinical features - chronic hypoxemia - cor pulmonale and Respiratory
failure.
• Diagnosis of occupational lung disease
 Chest x-ray - no changes without symptoms with progression to micronodular
mottling and haziness,nodules,fibroses and calcifications.
 PFTs and ABG – showing hypoxemia and hypercapnia.
Treatment - Preventive measures are key to limiting onset and severity and
medical treatments are Corticosteroids - Bronchodilators and O2 therapy.
 In critical care patients with pneumoconiosis that are in the ICU for acute
respiratory failure, can be put on non-invasive mechanical ventilation.

1.Lung parenchyma disorders……
• Mechanical ventilation in interstitial lung disease
High positive end-expiratory pressure (PEEP) levels greater than > 10 cm H2O,
APACHE score III-predicted mortality.
Ventilator setting should be low tidal volumes, low PEEP levels, and a rapid
respiratory rate should be the breathing pattern employed, regardless of
whether volume-controlled or pressure-controlled ventilation is used.
Due to the severe impairment of the respiratory mechanics, the fibrotic lung is at
high risk of developing ventilator-induced lung injury if you used high PEEP.
experts recommend keeping the static PL at end-inspiration below 15–20 cmH2O
in homogeneous and below 10–12 cmH2O in hetrogeneous lung parenchyma,
such as in ARDS.
For patients with acute exacerbation of ILD,lung protective ventilation like ARDS
is used.

C. ATELECTATIC DISORDERS
C1 - Acute (Adult) Respiratory Distress Syndrome (ARDS) :
Etiology –it occurs in association with other pathophysiologic processes
and mortality rate 30%-60%.
Causes of ARDS are - Severe trauma,Sepsis (>40%) ,aspiration of gastric
acid (>30%) ,fat emboli syndrome and Shock.
Pathogenesis of ARDS is widespread pulmonary inflammation leads to non
cardiogenic pulmonary edema associated with “leaky” pulmonary
capillaries.
Atelectasis associated with lack of surfactant resulting in decreases surface
tension in small alveoli and prevents them from collapsing which is
associated with inflammatory deposition of proteins.

Pathogenesis - Injury to alveoli from a wide variety of disorders results changes in
alveolar diameter.
Injury to pulmonary circulation results disruptions in O2 transport and utilization.
severe hypoxemia caused by intrapulmonary shunting of blood - Perfusion of
large numbers of alveoli that are poorly or not ventilated.
 Decrease in lung compliance due to loss or inactivation of surfactant with
subsequent increased recoil pressure - proteinaceous fluid fills alveoli that
impairs ventilation.
Decrease in FRC results in very stiff, noncompliant lungs associated with alveolar
edema and exudate exaggerate surface tension forces - alveolar closure leads to
atelectasis and loss of lung volume.

1. Lung parenchyma disorders……….
Early - Sudden marked respiratory distress - Slight increase in pulse rate -
Dyspnea - Low PaO2 - Shallow, rapid breathing.
 Late - Tachycardia - Tachypnea - Hypotension - Marked restlessness -Crackles,
rhonchi on auscultation - Use of accessory muscles - Intercostal and sternal
retractions – Cyanosis.
• Diagnosis of ARDS
Hallmark is hypoxemia refractory to increased levels of supplemental O2.
ABG - Hypoxia - Acidosis – Hypercapnia.
PFTs - Decrease in FVR - Decreased lung volumes - Decreased lung compliance
and VA/Q mismatch with large right-to-left shift.
 Chest x-ray - Normal with progression to diffuse bilateral “whiteout”lungs.

1. Lung parenchyma disorders……….
• According to the Kigali modification, ARDS was defined without the need of PEEP,
with the presence of bilateral opacities at chest radiograph or lung ultrasound
and hypoxia was defined with a cutoff of SpO2/FIO2 less than or equal to 315.

Diagnosis -Open-lung biopsy shows - Atelectasis - Hyaline membranes - Cellular
debris - Interstitial and alveolar edema.
• Treatment of ARDS
Mostly supportive - Enhance tissue oxygenation until inflammation resolves.
Identify underlying cause and address the cause.
Maintain fluid and electrolyte balance.
Block system inflammatory cells.
Volume ventilator using pressure support and mechanical ventilation with
positive end-expiratory pressure (PEEP).
Increases FRV and prevents alveolar collapse at end- expiration and forces edema
out of alveoli.

• Treatment of ARDS
 FIO2 reduced as soon as possible for improvement of pso2.
Inhaled nitric oxide
Mode A/C (CMV) Rate 15 –25 /min Volume/pressure control Pressure or volume
Tidal volume < 8 mL/kg IBW and plateau pressure <30 cm H2O Inspiratory time 1
s PEEP 5 cm H2O FiO2 Sufficient to maintain PaO2 > 60 mm Hg.
In ARDS, lung protection is provided using low tidal volumes, low plateau
transpulmonary pressures, but also a positive end-expiratory pressure (PEEP)
level sufficient to maintain oxygenation.

C2 - Severe Acute Respiratory Syndrome (SARS)
Etiology - Coronavirus
Primary mode of transmission through person to person - Respiratory droplets -
Contact with contaminated objects or surfaces touching mouth, nose, eyes.
 Virus epidemic associated with milder disease in infants - children and Severe
respiratory forms in adults.
Median incubation period 4-6 days - Patients become ill within 10 days of
exposure.
Overall mortality rate 10% and 50% for age > 60 years

Fever (>100.4 F) - Myalgias - Headache - Nonproductive cough and Dyspnea.
• Diagnosis
Chest x-ray – can have evidence within 1 week of symptom onset.
Laboratory - Lymphopenia - Normal/low WBC - Elevated liver enzymes -
Prolonged activated PTT.
 Respiratory specimens for PCR from nasopharynx,oropharynx or Sputum.
• Treatment
No definitive treatment recommendations
Symptoms of pneumonia - Hospitalization - O2 therapy - Mechanical ventilation
and Isolation.

• Ventilator Settings for ALI or ARDS Or SARS
Maintaining a low tidal volume
Monitoring plateau pressure
Setting PEEP based on the FiO2 requirement
Initial Vt : adjust Vt in steps of 1 ml/kg PBW every 1-2 hours until Vt = 6 ml/kg.
Measure inspiratory plateau pressure (Pplat; 0.5 second inspiratory pause) every
4 hours and after each change in PEEP or Vt.
If Pplat > 30 cm H2O, decrease Vt to 5 or 4 ml/kg .
If Pplat < 25 cm H2O, and Vt,6ml/kg, increase Vt by 1 ml/kg PBW
Make subsequent adjustments to RR to maintain pH 7.30-7.45, but do not exceed
RR = 35/min and do not increase set rate if PaCO2 <25 mm Hg
I:E ratio : Acceptable range = 1:1 – 1:3

Adjust FiO2 and PEEP proportionally to maintain PaO2 55-80 mm Hg or SpO2
88%-95%.
If pH remains <7.30 with RR = 35, consider bicarbonate infusion.
If pH <7.15, Vt may be increased (Pplat may exceed 30 cm H2O).
Alkalosis management - If pH > 7.45 and patient not triggering ventilator,
decrease set RR but not below 6 breath /min.
Using prone positioning and high levels of PEEP to maximize alveolar
recruitment.

1.Lung parenchyma disorders……..
C3 - Infant Respiratory Distress Syndrome or
Hyaline membrane disease
It occurs in 60% infants born <30 weeks not treated with
corticosteroids and in 35% for infants receiving antenatal steroids and
in 5% infants <34 weeks.
High risk factors are birth prior to 25 weeks gestation - birth at
advanced gestational age - poorly controlled diabetes in mother -
deliveries after antepartum hemorrhage - cesarean section without
antecedent labor - perinatal asphyxia - second twin - previous infant
with RDS and Rh factor incompatibility.
Causes is lack of surfactant and premature neonate has difficulty
maintaining high pressures needed for adequate oxygenation related
to soft, compliant chest that’s drawn inward with each inspiratory
contraction of diaphragm.

Pathogenesis - the neonate with IRDS must generate high intrathoracic pressures
(25-30 mm Hg) to maintain patent alveoli that Leads to increased alveolar surface
tension and decreased lung compliance.
Increased work of breathing and decreased ventilation - Progressive atelectasis -
Increased pulmonary vascular resistance - Profound hypoxemia – Acidosis.
Secondary cause is immaturity of capillary blood supply - Leads to VA/Q
mismatch, adding to hypoxemia and metabolic acidosis - Right-to-left shunt from
open foramen ovale or patent ductus arteriosus may increase hypoxemia.
Progressive damage to basement membrane and respiratory epithelial cells -
Causes patchy areas of atelectasis - Increased capillary permeability and leakage
of high-protein fluid into alveoli - Related to cellular damage.

Early - Shallow respirations, diminished breath sounds,intercostal,
subcostal, or sternal retractions,flaring of nares,hypotension,
bradycardia,peripheral edema,low body
temperature,oliguria,tachypnea (60-120 breaths/min).
 Late - frothy sputum - central cyanosis - expiratory grunting sound -
paradoxical respirations (seesaw movement of chest wall).
• Diagnosis
ABG - Hypoxemia, metabolic acidosis - Hypercapnia and respiratory
acidosis with progression of disease.
Chest x-ray - Diffuse whiteout or ground glass indicative of diffuse
bilateral atelectasis and alveolar edema and generalized lung
hypoinflation.

Chest x – ray of Hyaline membrane disease

 Lecithin-sphingomyelin (L/S) ratio greater than 2 : 1 determines ability of fetus
to secrete surfactant.
Presence of phosphatidyl glycerol indicates pulmonary maturity.
L/S ratio improves with administration of glucocorticoids before delivery.
• Treatment of Hyaline membrane disease
Prevention is primary goal - Maintain adequate oxygen levels (50-90 mm Hg) -
Low FIO2 settings related to high levels over time may result in further alveolar
damage, primary persistent pulmonary hypertension, and retrolental fibroplasia -
Mechanical ventilation with PEEP or continuous positive-airway pressure.
 Exogenous surfactant administration (bovine, porcine, or synthetic) - Decreases
mortality 50%.

1. Lung parenchyma disorders…..
High-frequency ventilation - Provides more uniform lung inflation - Improves lung
mechanics - Improves gas exchange.
 Antibiotics (infection after culture done or prophylactically until blood cultures
return).
Supportive therapy - Adequate intravenous nutrition - Fluid and electrolyte
balance - Minimal handling - Neutral thermal environment.
Babies with hyaline membrane disease and hypoxemia can be given assisted
ventilation in the form of continuous positive airway pressure (CPAP) or
intermittent positive pressure ventilation (IPPV).
The newborn can be initiated on CPAP (nasal or endotracheal) at 5-6 cm water
with FiO2 of 0.5.
Endotracheal CPAP was preferred in babies.
Despite using CPAP of 10-12 cm water (nasal), or 8-10 cm water (endotracheal)
with FiO2 of 0.8, if the newborn had hypoxemia or hypercarbia, it is an indication
to institute IPPV.

2. Pleural space disorders……
A.Pneumothorax
Primary pneumothorax - occur spontaneously and no underlying disease is
identified - Cigarette smoking is risk factor.
Secondary pneumothorax – occur as result of complications from preexisting
pulmonary disease like Asthma, emphysema, cystic fibrosis, infectious disease
(pneumonia, TB).
Tension pneumothorax - Traumatic origin - Results from penetrating or
nonpenetrating injury.
Pathogenesis of primary - Rupture of small subpleural blebs in apices - Air enter
pleural space, lung collapses, and rib cage springs out.
Pathogenesis of Secondary – As result of complications from an underlying lung
problem - May be due to rupture of cyst of bleb.

2. Pleural space disorders……..
 Pathogenesis of Tension - Results form buildup of air under pressure in pleural space -
Air enters pleural space but cannot escape during expiration - Lung on ipsilateral (same)
side collapses and forces mediastinum toward contralateral side - Decreases venous
return and cardiac output.
Open sucking chest wall wound - Air enters during inspiration but cannot escape during
expiration - Leads to shift of mediastinum.
 Iatrogenic pneumothorax occurs from a complication of a diagnostic or therapeutic
intervention such as transthoracic-needle aspiration, placement of a central venous
catheter, thoracentesis, lung, and or pleural biopsy, or barotrauma.
Small pneumothoraces (<20%) are usually not detectable on physical exam - Tachycardia
- Decreased or absent breath sounds on affected side - Hyperresonance - Sudden chest
pain on affected side (90%) - Dyspnea (80%.
Tension and large spontaneous pneumothorax are emergency situations - Severe
tachycardia - Hypotension - Tracheal shift to contralateral side - Neck vein distention -
Hyperresonance - Subcutaneous emphysema.

2. Pleural space disorders…….
• Diagnosis of pneumothorax
ABG - Decreased PaO2, acute respiratory alkalosis.
Chest x-ray - Expiratory films show better demarcation of pleural line than
inspiratory - Decompression of hemidiaphragm on side of pneumothorax - Pleural
line with absence of vessel markings peripheral to this line.
• Treatment of pneumothorax
Management depends on severity of problem and cause of air leak.
Lung collapse <15% - The patient may or may not be hospitalized - Treat
symptomatically and monitor closely.
Lung collapse >15%-25% - Chest tube placement with H2O seal and suction.
Limiting plateau airway pressures and reducing tidal volumes and fio2 less than
60% help minimize the risk of baro trauma.
NPPV can be used to deliver continuous PEEP or CPAP to prevents atelectasis,
maintains functional residual capacity and increases cardiac output.

Chemical pleurodesis - promotes adhesion of visceral pleura to parietal pleura to
prevent further ruptures.
Thoracotomy - Patients with further development of spontaneous pneumothorax
and blebs - Surgery permits stapling or laser pleurodesis of ruptured blebs.
Thorax drainage should be performed except in asymptomatic patients with
occult pneumothorax and Patients who are mechanically ventilated should be
treated immediately with a tube thoracostomy to prevent the development of
tension pneumothorax.
If mechanical ventilation is needed, the ventilator setting should support fistula
closure and limit inflationary pressure (peak, plateau and end-expiratory) and
volume.
Intubation should be performed during spontaneous breathing if possible
because positive-pressure ventilation may enlarge an incomplete rupture and
may worsen symptoms.

• Pleural Effusion
Pathologic collection of fluid or pus in pleural cavity as result of another disease
process.
Normally - 5-15 ml of serous fluid is contained in pleural space.
There is constant movement of pleural fluid from parietal pleural capillaries to
pleural space - Reabsorbed into parietal lymphatics.
• Five major types
1- Transudates
2 - Exudates
3 - Empyema due to infection in the pleural space
4 - Chylothorax or lymphatic
5 - Hemothorax

2. Pleural space disorders…….
Vary depending on cause and size of effusion - May be asymptomatic with <300
ml of fluid in pleural cavity - Dyspnea - Decreased chest wall movement - Pleuritic
pain (sharp, worsens with inspiration) - Dry cough.
 Absence of breath sounds - Dullness to percussion - Decreased tactile fremitus
over affected area - Contralateral tracheal shift (massive effusion).
• Diagnosis of pleural effusion
Chest x-ray - Pleural-based densities - Infiltrates - Hilar adenopathy - Loculation
of fluid in the pleural Space.
Thoracentesis - Analyze fluid and reduce amount of fluid - pH, LDH, glucose -
Presence of pathologic bacteria.
CT or ultrasonographic tests - Assist in complicated effusions - Distinguish mass
from large effusion.

 Treatment - Directed at underlying cause and relief of symptoms.
Thoracotomy for uncontrolled bleeding greater than 200 ml per hour .
The presence of pleural effusion is associated with a longer duration of
mechanical ventilation and ICU stay.
Drainage of large ≥500 ml pleural effusion in mechanically ventilated patients
improves oxygenation and end-expiratory lung volume.
Oxygenation improvement correlated with an increase in lung volume and a
decrease in trans pulmonary pressure.
Respiratory system compliance, end-expiratory lung volume, and PaO2/FIO2 ratio
all improved.

3. Extra – pulmonary disorders……
A. Neuro muscular diseases
 In NMD due to progressive inspiratory muscle weakness and increasing elastic
load induced by reduced lung and thorax compliance, these patients suffer from a
progressive decline in vital capacity (VC) and increase in work of breathing.
A rapid–shallow breathing pattern may be associated with increased work of
breathing and an inability to take deep breaths, leading to chronic micro -
atelectasis and decreased lung and chest wall compliance.
Bulbar muscle weakness (facial, oropharyngeal and laryngeal muscles) can affect
the ability to speak, swallow and clear airway secretions, with the possibility of an
increased likelihood of aspiration.
Significant reduction in VC and restrictive ventilatory pattern is usually seen in
NMD patients.

A1. Poliomyelitis
Viral disease in which poliovirus attacks motor nerve cells of spinal cord and
brainstem.
New cases rare because of mass vaccination and usually occur in unvaccinated
immigrants - 95% infections asymptomatic.
• Clinical feature
Fever - Headache - Vomiting - Diarrhea - Constipation - Sore throat - Chronic
respiratory insufficiency - Function generally recovers.

3. Extra – pulmonary disorders…….
A2. Amyotrophic Lateral Sclerosis
Clinical feature - males > females.
Degenerative disease of nervous system.
Involves upper and lower motor neurons.
Progressive muscle weakness and wasting.
Muscles innervated from spinal and cranial nerves affected - Eventually profound
weakness of respiratory muscles and death.
There is no cure for ATLS and most patients die after 3 to 5 years of symptom
onset.

3. Extra – pulmonary disorders…….
A3 . Duchenne muscular Dystrophies
Hereditary (X-linked recessive)
• Symptoms
• Progressive muscular weakness - Initially in lower extremities, and wasting.
Respiratory muscles become involved
Leads to hypoxia, hypercapnia, frequent respiratory infections.
 Occur in later years (20-30s).

3. Extra – pulmonary disorders….
A4. Guillain-Barré Syndrome
Demyelination of peripheral nerves in history of recent viral or bacterial illness
(66% of cases) followed by ascending paralysis.
Infection involving Campylobacter jejuni often precedes diagnosis.
 Weakness and paralysis begin symmetrically in LEs and ascend proximally to UEs
and trunk.
Severe cases - Respiratory muscle weakness accompanies limb and trunk
symptoms.
Natural history of disease leads to recovery.
Minor residual motor deficits (15%-20%).

3. Extra – pulmonary disorders…..
A5 .Myasthenia Gravis
 Primary abnormality at neuromuscular junction.
Impairment by decreased number of receptors on muscle.
Weakness and fatigue of voluntary muscles.
Those innervated by cranial nerves.
Peripheral and respiratory muscles can be affected.
Symptoms often managed by appropriate therapy.
Respiratory failure can be due to increasing severity of illness or medication.
Individual episodes of respiratory failure are potentially reversible.

• Indications for Mechanical Ventilation in Patients with Neuromuscular Disease
Progressive ventilatory failure
Acute ventilatory failure
studies show that long-term noninvasive mechanical ventilation (NIV) especially
bilevel pressure ventilators improves symptoms, gas exchange, quality of life like
for speech, sleep, swallowing, comfort, appearance and security.
 Tracheostomy ventilation may be preferred by patients unable to protect their
airways and who wish to maximise survival or when the patient is ventilator
dependent for most of the day.
Oxygenation is not usually an issue
Use CMV (A/C), VCV, Tidal volume should be 4–6 for ARDS patients and 6–
8 ml/kg PBW in patients without ARDS.low PEEP for ARDS patients and titrate fio2
based on pso2.

3 .Extra – pulmonary disorders……
A1 - Chest wall deformities
Hypercapnic ventilatory failure may occur in most chest wall deformities.
Thier physiological effect is, particularly a restrictive ventilatory defect and
decreased compliance of the chest wall.
mechanical abnormalities prevent the lung from normal degree of lung inflation
and deflation.
Noninvasive positive pressure ventilation using full face mask or a mouthpiece
with either pressure- or volume-preset ventilation is likely to be effective.
A peak inspiratory pressure of 20–25 cmH2O is often required with pressure-
preset ventilation and an inspiratory time of 0.8–1 s with an expiratory time of
∼2 s.
Positive end expiratory pressure is not essential, apart from in some bilevel
pressure-support systems useful at a level of 2–4 cmH2O .

A1 .Kyphoscoliosis
 Pathogenesis - bone deformity of chest wall resulting from kyphosis and
scoliosis.
Higher deformity in vertebral column, greater compromise of respiratory status -
Lung volumes compressed - Atelectasis, VA/Q mismatch, hypoxemia.
Clinical manifestations - Dyspnea on exertion - Rapid, shallow breathing - Chest
wall deformity - Ribs protruding backward, flaring on convex side, crowded on
concave side – Hypoxia , CO2 retention (late).
 Diagnosis - PFTs - Hypercapnia, hypoxia - Decreased lung volumes and capacities
- Increased pulmonary arterial pressures.
Chest x-ray - Accentuated bony curves.

3. Extra – pulmonary disorders….
• Treatment Kyphoscoliosis
• Depends on severity and age of patient
Curvatures <20 degrees - Monitor on regular basis - Postural exercise program -
External braces for moderate scoliosis.
 Curvatures >40 degrees - Electrical stimulation of paraspinal muscles - Spinal
fusion - Spinal instrumentation (Harrington rod) placement for surgical
stabilization.
Curvatures >60 degrees - Correlate with poor pulmonary function in later life.

3. Extra – pulmonary disorders…..
A2. Ankylosing Spondylitis
Chronic inflammation at site of ligamentous Insertion into spine or sacroiliac
joints - Respiratory system affected by limited chest expansion and formation of
pulmonary fibrosis in upper lobes.
 More common in males (10:1) - Common in 2nd or 3rd decade of life - Cause is
unknown - 90% have positive HLA-B27 antigen - Transient acute arthritis of
peripheral joints (50%).
Pathogenesis - Progressive, inflammatory disease - Immobility of vertebral joints
and fixation of ribs - Inflammation affects articular processes, costovertebral
joints, sacroiliac joints - Fibrotic response leads to joint calcification, ligament
ossification, and skeletal immobility.

Low to mid-back pain and stiffness increased with prolonged rest - Pain and
stiffness decrease with exercise.
Restrictive lung dysfunction - Rib cage movement reduction - Chest wall muscular
atrophy.
Breathing by excursion of diaphragm with rib cage immobilization.
• Diagnosis
PFTs - Decreased VC, TLC, compliance of respiratory system (chest wall).
Chest x-ray - Changes are seen in sacroiliac joints - Destruction of cartilage -
Erosion of bone - Calcification - Bony bridging of joint margins.
Laboratory - Elevated sedimentation rate (85%) - Decreased RBC - Increased WBC
- HLA-B27 antigen (90%).

• Treatment
Development of exercise program
Breathing and mobility exercises
Medications – NSAIDs
A3 .Flail Chest
 Two or more ribs fractured at two or more distant sites.
Results in unstable, free-floating chest wall segment
Moves paradoxically inward on inspiration
Sternal fractures can cause flail segment

3.Extra – pulmonary disorders…….
Pathogenesis - fracture leads to impairment of negative intrapleural pressure
generation - Causes decreased lung expansion on inspiration - Lung parenchymal
injury - Pulmonary contusion - Decreased lung compliance - Respiratory failure -
Interstitial and alveolar hemorrhage - VA/Q abnormalities.
Paradoxical motion of chest wall - SOB, cyanosis - Pain on inspiration –
Hypotension - Causes entire chest to move as unit rather than paradoxically.
Pneumothorax, hemothorax, subcutaneous emphysema are common.
• Diagnosis - ABG - Hypoxemia, low arterial PO2.
• Treatment - Managed with mechanical ventilation and Pain management

3.Extra – pulmonary disorders……
Full ventilatory support initially with Sedation, or paralysis may be necessary
initially.
Use Tidal volume 8-10 ml/kg with satisfactory lung compliance and 4-8 ml/kg
with pulmonary contusion and ARDS.
Titrate FiO2 to maintain SpO2 92-95%.

3.Extra – pulmonary disorders…..
A4. Disorders of Obesity
 Obesity - is - Excessive body fat - BMI >30 kg/m2 based on body weight and
height.
BMI >30 kg/m2 have increased mortality than with BMI between 20 and 25
kg/m2.
 Pathogenesis - Several hormones act on brain receptor to regulate appetite and
metabolism.
Leptin binds to brain receptors, causes releases of neuropeptides - Increase
metabolic rate.
• Effect of obesity on respiratory system
 May be associated with hypoventilation and airway obstruction.
Increased abdominal size which forces thoracic contents upward into chest cavity.

3.Extra – pulmonary disorders……
Decreases lung expansion and diaphragmatic shortening.
Sleep apnea syndrome - Soft tissue deposits in neck and tissue predispose person
to upper airway obstruction.
Decreased alveolar ventilation, severe hypoxemia - Somnolence (daytime) -
Shortness of breath - Polycythemia - Cor pulmonale - Impotence - Headache –
Enuresis.
• Diagnosis - Hypothyroidism, Cushing syndrome, insulinoma, diabetes,
hyperlipidemia.
 ABG - Hypoxemia, hypercapnia
PFT - Decreased chest wall compliance, VC, TLC, ERV.

3. Extra – pulmonary disorders……..
• Treatment
O2 (morbid obesity)
Weight loss program
Aerobic exercise
 Obesity induces functional changes in the respiratory system, resulting in a
reduction of the end-expiratory lung volume, increased incidence of airway
closure and formation of atelectasis, and alterations in lung and chest wall
mechanics.
Non‐invasive ventilation (NIV) may be applied to avoid intubation in obese
patients with acute respiratory failure, without delaying intubation if needed.
In hypercapnic obese patients, higher positive end‐expiratory pressure (PEEP)
might be used for longer periods to reduce the hypercapnia level below 50
mmHg.
 Tidal volume should be 4–6 for ARDS patients and 6–8 ml/kg PBW in patients
without ARDS.low PEEP for ARDS patients and titrate fio2 based on pso2.

3.Extra – pulmonary disorders…….
A5. Chest wall burn
• Mechanical Ventilation of Patient with Burn and Inhalation Injury
Post-burn skin contractures of the anterior and lateral abdomen and chest may
result in respiratory compromise due to limitation of rib excursion.
Volume and pressure controlled ventilation most preferred mode in burn injury
patients.
But in inhalational injury ARDS patients lung protective ventilation is most
effective strategy i.e low tidal volume and low PEEP ventilation.
For inhalational injury consider bronchodilators,diuretics,secretion
clearance,prone postioning and Inhaled nitric oxide.
Titrate FiO2 for SpO2 ≧ 92.

References
 Annals of the American Thoracic Society ,Volume 11, Issue Effects of Pleural Effusion Drainage on
Oxygenation, Respiratory Mechanics, and Hemodynamics in Mechanically Ventilated Patients.
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1645517/ mechanical ventilation in hyaline membrane
disease.
 Ochiai, R. Mechanical ventilation of acute respiratory distress syndrome. j intensive care 3, 25 (2015).
https://doi.org/10.1186/s40560-015-0091-6.
 Ball, L., Pelosi, P. How I ventilate an obese patient. Crit Care 23, 176 (2019).
https://doi.org/10.1186/s13054-019-2466-x

mechanical ventilation in restrictive lung disease.pptx

mechanical ventilation in restrictive lung disease.pptx

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to mechanical ventilation in restrictive lung disease.pptx

Similar to mechanical ventilation in restrictive lung disease.pptx (20)

Recently uploaded

Recently uploaded (20)

mechanical ventilation in restrictive lung disease.pptx