Effect of Flow Rates of High-Flow Nasal Cannula on Extubation Outcomes: A Randomized Controlled Trial

Area of Science:

• Critical Care Medicine
• Respiratory Therapy
• Clinical Trials

Background:

• High-flow nasal cannula (HFNC) is increasingly used for postextubation oxygen therapy.
• Its potential to reduce reintubation rates is recognized, but optimal flow settings remain debated.
• Current practice often uses 30-50 L/min, with questions about higher settings' efficacy.

Purpose of the Study:

• To compare the effectiveness of 60 L/min versus 40 L/min HFNC flow rates in postextubation care.
• To determine if a higher HFNC flow rate reduces reintubation or need for noninvasive ventilation (NIV).
• To evaluate the impact of different HFNC flow rates on respiratory support escalation and mortality.

Main Methods:

• A randomized controlled trial involving 169 intubated patients postextubation.
• Patients were assigned to receive HFNC at either 40 L/min or 60 L/min for 24 hours.
• The primary outcome was a composite of reintubation or NIV use within 48 hours.

Main Results:

• No significant difference in the primary outcome (reintubation or NIV use) between groups (22.1% vs. 16.9%, P=.39).
• The 40 L/min group experienced a significantly higher rate of respiratory support escalation (27.9% vs. 9.6%, P=.002).
• This suggests that while the primary outcome was similar, higher flow may lead to more interventions.

Conclusions:

• Setting HFNC at 60 L/min did not significantly decrease reintubation or NIV use compared to 40 L/min in unselected patients.
• A 40 L/min HFNC setting with as-needed up-titration is a viable alternative to a fixed 60 L/min setting.
• The study may have lacked sufficient power to detect smaller differences between the flow rates.