From the Guidelines
High flow nasal cannula (HFNC) is not recommended as a primary treatment for apnea or respiratory effort in patients with stroke, as the current evidence is limited and primarily focused on acute hypoxaemic respiratory failure rather than stroke-specific populations. The most recent and highest quality study, published in the European Respiratory Journal in 2022 1, discusses the use of HFNC in acute respiratory failure, highlighting its benefits in improving hypoxaemia, reducing work of breathing, and enhancing comfort. However, this study does not specifically address the use of HFNC in stroke patients with apnea or respiratory effort.
When considering the use of HFNC in stroke patients, it is essential to note that the primary benefits of HFNC, such as reliable oxygen delivery, humidification, and a low level of positive end-expiratory pressure (PEEP), may not directly address the underlying causes of apnea or respiratory effort in this population. For stroke patients with increased respiratory effort or mild hypoxemia, other treatments, such as CPAP or BiPAP, may be more effective in stabilizing the upper airway and improving respiratory mechanics.
Key considerations for the use of HFNC in stroke patients include:
- Initiating HFNC at 30-40 L/min with FiO2 titrated to maintain oxygen saturation above 92-94% may be beneficial for patients with mild hypoxemia
- The positive pressure generated by HFNC (approximately 2-4 cmH2O) may help stabilize the upper airway, but this effect is less pronounced than with CPAP or BiPAP
- HFNC is generally well-tolerated and allows for eating, drinking, and speaking, making it more comfortable than mask-based ventilation
- Addressing the underlying neurological injury and providing respiratory support as needed is essential for central apneas related to stroke.
From the Research
High Flow Nasal Cannula (HFNC) in Patients with Stroke
- HFNC is an emerging technique that provides oxygen at high flows with an optimal degree of heat and humidification, which is well tolerated and easy to use in all clinical settings 2.
- The use of HFNC in acute respiratory failure is now routine as an alternative to conventional oxygen therapy (COT) and sometimes noninvasive ventilation (NIV) 2, 3.
Effect of HFNC on Apnea or Respiratory Effort
- A study found that HFNC therapy at a flow rate up to 50~60 L/min significantly decreased the apnea-hypopnea index and the total arousal index in post-acute ischemic stroke patients with nasogastric intubation and obstructive sleep apnea (OSA) 4.
- Another study found that HFNC therapy did not improve sleep-disordered breathing and sleep quality in patients with acute stroke, and nonadherence and discomfort were observed in HFNC therapy 5.
- HFNC may be useful as a temporary treatment option for OSA in post-acute ischemic stroke patients with nasogastric intubation, but CPAP therapy is suggested after the nasogastric tube is removed 4.
Clinical Applications of HFNC
- HFNC is effective at reducing dyspnoea and improving oxygenation in respiratory failure from a variety of aetiologies, thus avoiding escalation to more invasive supports 2.
- HFNC has been adopted to treat de novo hypoxaemic respiratory failure, exacerbation of chronic obstructive pulmonary disease (COPD), postintubation hypoxaemia, and used for palliative respiratory care 2.
- The role of HFNC as a respiratory support strategy in adults has been established, with strong recommendations for its use in hypoxemic respiratory failure and conditional recommendations for its use following extubation and postoperatively in high-risk patients 3.