In critically ill adults undergoing endotracheal intubation, the ramped position does not significantly improve oxygenation compared with the sniffing position, according to results of a multicenter, randomized trial of 260 patients treated in an intensive care unit.
Moreover, “[ramped] position appeared to worsen glottic view and increase the number of attempts required for successful intubation,” wrote Matthew W. Semler, MD, of Vanderbilt University Medical Center, Nashville, Tenn., and his coauthors ().
The ramped and sniffing positions are the two most common patient positions used during emergent intubation, according to investigators. The sniffing position is characterized by supine torso, neck flexed forward, and head extended, while ramped position involves elevating the torso and head.
Some believe the ramped position may offer superior anatomic alignment of the upper airway; however, only a few observational studies suggest it is associated with fewer complications than the sniffing position, the authors wrote.
Accordingly, they conducted a multicenter randomized trial with a primary endpoint of lowest arterial oxygen saturation, hypothesizing that the endpoint would be higher for the ramped position: “Our primary outcome of lowest arterial oxygen saturation is an established endpoint in ICU intubation trials, and is linked to periprocedural cardiac arrest and death,” they wrote.
The investigators instead found that median lowest arterial oxygen saturation was not statistically different between groups, at 93% for the ramped position, and 92% for the sniffing position (P = 0.27), published data show.
Further results showed that the ramped position appeared to be associated with poor glottic view and more difficult intubation. The incidence of grade III (only epiglottis) or grade IV (no visible glottis structures) views were 25.4% for ramped vs. 11.5% for sniffing (P = .01), while the rate of first-attempt intubation was 76.2% for ramped vs 85.4% for sniffing (P = .02).
While the findings are compelling, the authors were forthcoming about the potential limitations of the study and differences compared with earlier investigations. Notably, they said, all prior controlled trials of patient positioning during endotracheal intubation were conducted in the operating room, rather than in the ICU.
Also, the operators’ skill levels may further explain differences in this study’s outcomes from those of similar studies, the researchers noted. Earlier studies included patients intubated by one or two senior anesthesiologists from one center, while this trial involved 30 operators across multiple centers, with the average operator having performed 60 previous intubations. “Thus, our findings may generalize to settings in which airway management is performed by trainees, but whether results would be similar among expert operators remains unknown,” the investigators noted.
The authors reported no potential conflicts of interest. One coauthor reported serving on an advisory board for Avisa Pharma.