From the Research
The decision to make a patient NPO while on high flow nasal cannula (HFNC) should be individualized based on the patient's clinical condition, respiratory status, and risk of aspiration. Generally, patients who are tachypneic (respiratory rate >30 breaths/minute), have increased work of breathing, are using accessory muscles, have altered mental status, or are at high risk of requiring intubation should be made NPO. For patients on HFNC with flow rates >30 L/min or FiO2 >50%, clinicians should exercise caution regarding oral intake due to the higher likelihood of respiratory deterioration, as supported by a study that found high-flow nasal cannula flow rates above 40 L/min were associated with choking and decreased swallowing function in healthy volunteers 1. Patients who are stable on HFNC with lower flow requirements, normal mental status, intact swallowing function, and showing improvement may be candidates for oral intake, potentially starting with clear liquids and advancing as tolerated. The rationale behind making unstable patients NPO is to prevent aspiration, which could worsen respiratory status and lead to aspiration pneumonia, particularly in patients who may require emergent intubation. Regular reassessment of respiratory status and swallowing function is essential to determine when oral intake can be safely initiated or advanced. A recent scoping review highlighted the importance of considering the "8 D's" of high-flow nasal cannula risk, including deterioration, death, device-related events, delay, disposition, debility, distress, and dysphagia, when making decisions about NPO status 2.
Some key considerations for NPO status in patients on HFNC include:
- Respiratory rate and work of breathing
- Mental status and risk of aspiration
- Flow rate and FiO2 requirements
- Swallowing function and risk of dysphagia
- Overall clinical condition and risk of deterioration or death
By individualizing the decision to make a patient NPO based on these factors, clinicians can help minimize the risks associated with HFNC therapy and optimize patient outcomes, as supported by a systematic review and meta-analysis that found HFNC to be effective in reducing treatment failure and intubation rates in patients with acute respiratory failure 3.