High-flow nasal cannula (HFNC) therapy delivers heated and humidified oxygen through nasal prongs at high flow rates. It has become a common form of non-invasive respiratory support. HFNC works by washing out the upper airways, reducing dead space, providing PEEP, and decreasing the work of breathing. It is indicated for various respiratory conditions and failures. Healthcare providers must monitor patients on HFNC closely and be aware of potential complications like nasal discomfort or aspiration. Key equipment includes nasal prongs, an oxygen source, heater-humidifier, and flow generator.

1. HHHFNC
Dr.Mukesh kumar Jaswant Singh Pachahara
Anaesthesiology department,NMC&H

2. Introduction
Components
HHHFNC means heated(31-37 degree),humidified (upto
99% humidity) & adjustable high flow oxygen at a
concentration of 21%-100% through Nasal canula.
High Flow Nasal Cannula (HFNC) therapy has evolved over the past few decades as a
non-invasive respiratory support modality. The concept of delivering high flow rates of
humidified oxygen-enriched air through nasal cannulae originated from techniques used
in neonatal care to improve oxygenation and reduce the need for invasive mechanical
ventilation.
In the early 2000s, HFNC therapy gained popularity as an alternative to conventional
oxygen therapy and non-invasive ventilation in adult patients with acute respiratory
failure. Its use expanded due to its ability to provide high levels of oxygen while also
delivering positive end-expiratory pressure (PEEP), which helps maintain lung volume
and improve oxygenation.
Research and clinical trials have since demonstrated the effectiveness of HFNC therapy
in various clinical settings, including acute respiratory distress syndrome (ARDS),
pneumonia, chronic obstructive pulmonary disease (COPD) exacerbations, and post-
extubation respiratory support.
Today, HFNC is widely used in hospitals and intensive care units (ICUs) around the
world as a valuable tool in the management of respiratory failure, providing a balance
between oxygen delivery, patient comfort, and avoidance of invasive ventilation when
possible.

3. Mechanism of action:
The mechanism of action of High Flow Nasal Cannula (HFNC) therapy involves several key components:
1. High Flow Rates: HFNC delivers a high flow of heated and humidified oxygen-enriched air, typically ranging from 30 to 60 liters
per minute. This high flow rate helps to wash out the upper airways, reduce anatomical dead space, and improve gas exchange
efficiency.
2. Humidification: The delivered gas is heated and humidified to near-physiological levels, which helps prevent mucosal drying,
reduces airway resistance, and improves mucociliary clearance. This humidification is crucial for patient comfort and tolerance of the
therapy.
3. Positive Airway Pressure: HFNC therapy can generate a modest amount of positive end-expiratory pressure (PEEP) due to the flow
of gas into the airways. This PEEP effect helps to maintain lung volume, improve alveolar recruitment, and enhance oxygenation.
4. Decreased Work of Breathing: The high flow rate of warmed and humidified gas reduces the work of breathing by decreasing
inspiratory resistance and improving respiratory mechanics. This can be particularly beneficial for patients with respiratory distress or
increased respiratory effort.
5. Nasal Cannula Design: HFNC systems typically utilize specially designed nasal cannulae with larger bore prongs to accommodate
the high flow rates and minimize discomfort and nasal trauma for the patient.
Overall, HFNC therapy provides a combination of oxygenation, ventilation, and respiratory support while offering advantages such as
improved patient comfort, better tolerance, and reduced need for invasive ventilation in selected patient populations.

4. Indications
High-flow nasal cannula (HFNC) therapy is
commonly indicated for patients with respiratory
distress or failure due to various conditions,
including:
1. Acute hypoxemic respiratory failure
2. Acute exacerbation of chronic obstructive
pulmonary disease (COPD)
3. Acute respiratory distress syndrome (ARDS)
4. Pneumonia
5. Post-extubation respiratory support
6. Pre-oxygenation before intubation
7. Palliative care for comfort in end-of-life
situations
These are some of the primary indications, but
HFNC therapy can also be considered in other
situations where supplemental oxygen and
respiratory support are needed.

5. Contraindications
While high-flow nasal cannula (HFNC) therapy is generally safe and well-tolerated, there are certain
contraindications and precautions to consider:
1. Nasal obstruction: Significant nasal obstruction can impair the delivery of high-flow oxygen and may not be
suitable for HFNC therapy.
2. Facial trauma: Patients with facial trauma, particularly involving the nasal region, may not be suitable
candidates for HFNC due to the potential for inadequate seal and air leakage.
3. Recent nasal surgery: Patients who have undergone recent nasal surgery may have compromised nasal
anatomy, making HFNC therapy less effective or potentially harmful.
4. Risk of aspiration: HFNC therapy may not be appropriate for patients at high risk of aspiration, as it does not
provide positive airway pressure to prevent aspiration.
5. Unable to tolerate mask interface: Some patients may not tolerate the sensation of the nasal prongs or the
flow of air, making HFNC therapy uncomfortable or intolerable.
6. Inability to protect airway: Patients who are unable to protect their airway may not be suitable candidates for
HFNC therapy, as it does not provide ventilatory support or protect against airway collapse.
These contraindications should be carefully considered by healthcare providers when determining the
appropriateness of HFNC therapy for individual patients.

6. Monitoring during high-flow nasal cannula (HFNC) therapy is crucial to ensure the patient's safety and optimize treatment effectiveness.
Key parameters to monitor include:
1. Respiratory rate: Regular assessment of the patient's respiratory rate helps evaluate the effectiveness of HFNC therapy in reducing respiratory distress.
2. Oxygen saturation (SpO2): Continuous monitoring of oxygen saturation provides real-time feedback on the patient's oxygenation status and helps titrate
the oxygen flow rate appropriately.
3. Arterial blood gases (ABGs): Periodic sampling of arterial blood gases may be necessary to assess oxygenation and ventilation status more accurately,
especially in patients with severe respiratory failure.
4. Clinical signs: Observation of clinical signs such as respiratory effort, use of accessory muscles, and level of consciousness helps gauge the patient's
response to HFNC therapy and detect any deterioration in respiratory status.
5. Nasal prong fit: Regular assessment of the fit and placement of nasal prongs ensures optimal delivery of oxygen and reduces the risk of nasal mucosal
injury or air leakage.
6. Secretions: Monitoring for excessive secretions or signs of airway obstruction helps prevent complications such as aspiration or respiratory distress.
7. Patient comfort: Assessing the patient's comfort level with HFNC therapy and addressing any discomfort or intolerance promptly improves compliance and
treatment adherence.
8. Fluid balance: Monitoring fluid intake and output helps prevent fluid overload, especially in patients with heart failure or renal impairment receiving high-
flow oxygen therapy.
9. Chest imaging: Periodic chest imaging, such as chest X-rays, may be indicated to assess lung pathology and evaluate treatment response in patients with
underlying respiratory conditions.
Regular and systematic monitoring of these parameters allows healthcare providers to adjust HFNC settings, intervene promptly in case of complications, and
optimize patient outcomes. Close collaboration between clinicians, respiratory therapists, and nursing staff is essential to ensure comprehensive monitoring and
management of patients receiving HFNC therapy.
MONITORING:

7. EQUIPMENTS:
1. Nasal cannula interface: The nasal cannula consists of soft, flexible prongs that are inserted into the patient's nostrils to deliver the high-flow oxygen. The prongs are
designed to fit comfortably and securely to minimize air leakage.
2. Oxygen source: A source of medical-grade oxygen, such as an oxygen concentrator or oxygen cylinder, is required to supply the high-flow oxygen delivered through the
nasal cannula.
3. Air/oxygen blender: An air/oxygen blender is used to mix medical-grade oxygen with room air to achieve the desired oxygen concentration. This allows precise control
over the FiO2 (fraction of inspired oxygen) delivered to the patient.
4. Heater humidifier: A heater humidifier unit is used to warm and humidify the oxygen before it is delivered to the patient. This helps prevent mucosal drying and irritation
and enhances patient comfort.
5. Flow generator: The flow generator, also known as a high-flow device or flow meter, regulates the flow rate of oxygen delivered through the nasal cannula. It allows for
high flow rates typically ranging from 20 to 60 liters per minute (L/min) or higher, depending on the patient's needs.
6. Tubing: Flexible tubing connects the flow generator to the nasal cannula interface, allowing for the delivery of heated and humidified oxygen to the patient.
7. Monitoring equipment: Devices for monitoring vital signs, such as pulse oximeters for continuous oxygen saturation monitoring and respiratory rate monitors, are
essential for assessing the patient's response to HFNC therapy.
8. Water reservoir: A water reservoir is used to supply distilled water to the heater humidifier for humidification of the oxygen. Regular refilling and maintenance of the
water reservoir are necessary to ensure proper humidification.
9. Adjustable straps or headgear: Straps or headgear may be provided to secure the nasal cannula in place and prevent displacement, especially during patient movement or
changes in position.
These equipment components work together to deliver high-flow oxygen therapy effectively and safely to patients requiring respiratory support. Regular maintenance,
cleaning, and monitoring of the equipment are essential to ensure optimal performance and patient comfort.
High-flow nasal cannula (HFNC) therapy requires specific equipment to deliver heated and humidified oxygen at a
high flow rate. The key components of HFNC equipment include:

8. COMPONENTS:

9. COMPLICATIONS:
There are potential complications that healthcare providers should be aware of:
1. Nasal discomfort: Some patients may experience nasal dryness, irritation, or discomfort due to the high flow of warm and
humidified air.
2. Nasal trauma: Prolonged or improper use of nasal prongs can lead to nasal mucosal injury, including ulceration or
necrosis.
3. Airway obstruction: In rare cases, the high flow rate of oxygen can lead to airway obstruction, particularly in patients
with underlying airway pathology or excessive secretions.
4. Barotrauma: HFNC therapy delivers oxygen at higher pressures than conventional oxygen therapy, increasing the risk of
barotrauma, such as pneumothorax or pneumomediastinum, especially in patients with underlying lung pathology.
5. Delayed intubation: In some cases, HFNC therapy may delay the need for intubation and mechanical ventilation,
potentially leading to worsening respiratory distress or failure if not closely monitored.
6. Infection: Improper cleaning and maintenance of HFNC equipment can increase the risk of nosocomial infections,
including pneumonia or sinusitis.
7. Mask intolerance: Some patients may experience claustrophobia or discomfort with the nasal prongs, leading to non-
compliance with HFNC therapy.
These complications underscore the importance of careful patient selection, monitoring, and appropriate management when
using HFNC therapy. Healthcare providers should closely monitor patients for signs of intolerance or worsening respiratory
status and intervene promptly if complications arise.

10. While the pressure generated by HFNC is variable and not directly controlled like in mechanical ventilation, it can still create positive
airway pressure during both inspiration and expiration.
1. Increased Oxygenation: HFNC delivers a high flow of oxygen-enriched air, which can improve oxygenation in patients with
respiratory failure by reducing the patient's work of breathing and providing a more consistent FiO2 (fraction of inspired oxygen)
compared to traditional oxygen delivery methods.
2. Washout of Dead Space: The high flow rate of air delivered by HFNC can help flush out the anatomical dead space in the upper
airways, reducing the rebreathing of exhaled CO2 and improving ventilation-perfusion matching.
3. Reduced Airway Resistance: The flow of air from HFNC can help reduce airway resistance, making it easier for the patient to
breathe and decreasing the work of breathing.
4. Improved Comfort: The warm and humidified air provided by HFNC can improve patient comfort, reduce airway irritation, and
decrease the risk of nasal mucosal damage compared to traditional oxygen therapy.
5. Potential for Non-Invasive Ventilation: In some cases, HFNC may delay or obviate the need for invasive mechanical ventilation
by providing sufficient respiratory support and improving oxygenation and ventilation in patients with respiratory failure.
6. Reduced Work of Breathing: HFNC can help reduce the patient's work of breathing by providing a constant flow of air, which
decreases the effort required to inhale and exhale. This can be particularly beneficial in patients with respiratory distress or fatigue.
7. Improved Secretion Clearance: The high flow of air provided by HFNC can help mobilize and clear respiratory secretions, which
can be beneficial in patients with conditions such as pneumonia or bronchiolitis.

11. 8. Better Patient Compliance: HFNC therapy is often better tolerated by patients compared to other forms of respiratory
support, such as non-invasive ventilation or invasive mechanical ventilation. The comfortable delivery of warm, humidified
air through nasal prongs can lead to improved patient compliance and longer duration of therapy.
9. Adjustability: HFNC systems typically allow for adjustment of flow rates and FiO2 levels to meet the specific needs of
individual patients. This flexibility enables healthcare providers to tailor the therapy to achieve optimal oxygenation and
ventilation while minimizing potential side effects.
10. Potential for Use Outside the ICU: HFNC therapy can be used not only in the intensive care unit (ICU) but also in other
clinical settings, such as emergency departments, general wards, and even pre-hospital settings. Its portability and ease of use
make it a versatile tool for providing respiratory support across various healthcare settings.
HFNC therapy offers a range of benefits for patients with respiratory failure, including improved oxygenation, reduced work
of breathing, secretion clearance, and better patient comfort and compliance. It has become an essential tool in the
management of acute and chronic respiratory conditions.

12. REFERENCES:
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compared with conventional oxygen therapy for acute hypoxemic respiratory failure: a systematic review and meta-analysis.
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