Recently published results from a clinical trial showed that for critically ill adults needing tracheal intubation for emergency airway support, the method health care providers choose to use for providing supplemental oxygen before the intubation procedure affects the patient’s risk of hypoxemia, or potentially life-threatening low levels of blood oxygen.
Preoxygenation is the administration of supplemental oxygen prior to the start of a procedure to increase the content of oxygen in the lungs and decrease the risk of hypoxemia during the tracheal intubation procedure. In current clinical care, most critically ill adults receive preoxygenation using an oxygen mask.
Researchers at the University of Wisconsin School of Medicine and Public Health were involved in the Department of Defense-funded Pragmatic Trial Examining Oxygenation Prior to Intubation, or PREOXI, clinical trial, led nationally by Vanderbilt University Medical Center. The trial compared the two most commonly used methods to preoxygenate patients prior to tracheal intubation: preoxygenation with an oxygen mask and preoxygenation with noninvasive ventilation. The study showed that the noninvasive ventilation method, which supports breathing by using a tight-fitting respiratory mask connected to BPAP, or bilevel positive airway pressure, reduced the risks associated with the intubation procedure.
“More than 1.5 million critically ill adults undergo emergency tracheal intubation each year in the United States,” said Dr. Jonathan Casey, assistant professor of medicine at Vanderbilt University Medical Center and a senior principal investigator in the trial. “Hypoxemia occurs during 10 percent to 20 percent of those tracheal intubations in the emergency department or intensive care unit and may lead to cardiac arrest and death. Our study found that among critically ill adults undergoing tracheal intubation, preoxygenation with noninvasive ventilation decreases the incidence of hypoxemia during intubation compared to preoxygenation with an oxygen mask.”
The multicenter, randomized trial was conducted in 24 emergency departments and intensive care units in the United States. Critically ill adults undergoing tracheal intubation were randomly assigned to two groups: preoxygenation using noninvasive ventilation or preoxygenation using an oxygen mask.
The investigators assessed whether preoxygenation with noninvasive ventilation would prevent hypoxemia during intubation, defined as an oxygen saturation less than 85 percent during the interval between induction and two minutes after tracheal intubation.
The study illustrates how involvement in pragmatic clinical trials at academic health systems can yield data that ultimately improve outcomes for patients.
- Stephen Halliday
In the 1,301 patients enrolled, hypoxemia occurred in 57 of the 624 patients, or 9.1 percent, in the noninvasive ventilation group and 118 of the 637 patients, or 18.5 percent, in the oxygen mask group. Further, it appeared that by preventing hypoxemia during tracheal intubation, preoxygenation with noninvasive ventilation also prevented cardiac arrest, the most feared complication of tracheal intubation, which occurred in one patient in the noninvasive ventilation group and seven patients in the oxygen mask group.
These findings were important because they could change the standard of care for intubations in emergency departments and intensive care units, according to Dr. Stephen Halliday, assistant professor of medicine, who along with Dr. Micah Long, associate professor of anesthesiology, both at the UW School of Medicine and Public Health, led the trial locally at the school and UW Health.
“The study illustrates how involvement in pragmatic clinical trials at academic health systems can yield data that ultimately improve outcomes for patients,” said Halliday, who is also a pulmonologist at UW Health.
Prior to this trial, international guidelines stated that preoxygenation with either noninvasive ventilation or an oxygen mask is acceptable, but results of this trial could lead to changes to those clinical guidelines, according to the study’s authors.
“Applying these results to clinical care by routinely using noninvasive ventilation for preoxygenation before tracheal intubation has the potential to prevent tens of thousands of patients each year from experiencing hypoxemia and cardiac arrest,” said Dr. Kevin Gibbs, first author on the study and a critical care medicine physician at Wake Forest School of Medicine.
