RCT: Preoxygenation with Noninvasive Ventilation Reduced Hypoxemia during Emergency Intubation
19 Sep, 2024 | 12:53h | UTCBackground: Hypoxemia during tracheal intubation in critically ill adults increases the risk of cardiac arrest and death. Preoxygenation aims to mitigate this risk, but the optimal method remains uncertain. Noninvasive ventilation (NIV) may offer advantages over oxygen masks by providing positive pressure and higher inspired oxygen fractions, but evidence is limited.
Objective: To determine whether preoxygenation with noninvasive ventilation reduces the incidence of hypoxemia during tracheal intubation compared to preoxygenation with an oxygen mask among critically ill adults.
Methods: In a multicenter, pragmatic, unblinded, randomized trial conducted at 24 emergency departments and intensive care units in the United States, 1301 critically ill adults (age ≥18 years) undergoing tracheal intubation were randomized 1:1 to receive preoxygenation with either noninvasive ventilation (n=645) or an oxygen mask (n=656). Patients already receiving positive-pressure ventilation or at high risk of aspiration were excluded. In the NIV group, preoxygenation was administered using a tight-fitting mask connected to a ventilator, with an FiO₂ of 100%, expiratory pressure ≥5 cm H₂O, and inspiratory pressure ≥10 cm H₂O. In the oxygen-mask group, preoxygenation was provided using a nonrebreather mask or bag-mask device without manual ventilation, with oxygen flow ≥15 liters per minute. The primary outcome was hypoxemia during intubation, defined as oxygen saturation <85% between induction of anesthesia and 2 minutes after tracheal intubation.
Results: Hypoxemia occurred in 9.1% of patients in the NIV group versus 18.5% in the oxygen-mask group (difference –9.4 percentage points; 95% CI, –13.2 to –5.6; P<0.001). Cardiac arrest during intubation occurred in 0.2% of patients in the NIV group and 1.1% in the oxygen-mask group (difference –0.9 percentage points; 95% CI, –1.8 to –0.1). Aspiration occurred in 0.9% of patients in the NIV group and 1.4% in the oxygen-mask group (difference –0.4 percentage points; 95% CI, –1.6 to 0.7). No significant differences were observed in other adverse events.
Conclusions: Preoxygenation with noninvasive ventilation significantly reduced the incidence of hypoxemia during tracheal intubation among critically ill adults compared to preoxygenation with an oxygen mask, without increasing the risk of aspiration.
Implications for Practice: Preoxygenation with noninvasive ventilation should be considered for critically ill adults undergoing emergency tracheal intubation to reduce the risk of hypoxemia and potential cardiac arrest. Clinicians should ensure appropriate equipment and training are available for the use of NIV during preoxygenation.
Study Strengths and Limitations: Strengths include a large sample size, multicenter design across diverse emergency departments and ICUs, and pragmatic approach enhancing generalizability. Limitations include exclusion of patients already receiving positive-pressure ventilation or at high risk of aspiration, potentially limiting applicability to these populations. The unblinded design may introduce bias, although outcome data were collected by independent observers.
Future Research: Further studies are needed to evaluate the effectiveness of noninvasive ventilation for preoxygenation in patients at high risk of aspiration and to compare its efficacy with high-flow nasal cannula. Research should also assess long-term clinical outcomes and cost-effectiveness of implementing NIV for preoxygenation.