For patients being placed on a breathing machine, a breathing tube must be placed in the mouth.  During placement of a breathing tube, low oxygen levels may occur.  Whether placing a breathing tube while the patient’s head and shoulders were elevated (“ramped position”) could prevent low oxygen levels compared to placement of a breathing tube with the patient laying flat (“sniffing position”) was not known.  Among 260 patients in 4 intensive care units, the CHECK-UP trial found that placing a breathing tube in the ramped position did not prevent low oxygen levels.  Placing a breathing tube in the ramped position appeared to be more difficult than placing a breathing tube with the patient in the sniffing position.  These findings suggest that, for many patients in the intensive care unit, placing a breathing tube in the sniffing position may be simpler and easier than in the ramped position.

Background: Hypoxemia is the most common complication during endotracheal intubation of critically ill adults. Intubation in the ramped position has been hypothesized to prevent hypoxemia by increasing functional residual capacity and decreasing the duration of intubation, but has never been studied outside of the operating room.

Methods: Multicenter, randomized trial comparing the ramped position (head of the bed elevated to 25°) with the sniffing position (torso supine, neck flexed, and head extended) among 260 adults undergoing endotracheal intubation by pulmonary and critical care medicine fellows in four ICUs between July 22, 2015, and July 19, 2016. The primary outcome was lowest arterial oxygen saturation between induction and 2 minutes after intubation. Secondary outcomes included Cormack-Lehane grade of glottic view, difficulty of intubation, and number of laryngoscopy attempts.

Results: The median lowest arterial oxygen saturation was 93% (interquartile range [IQR], 84%-99%) with the ramped position vs 92% (IQR, 79%-98%) with the sniffing position (P = .27). The ramped position appeared to increase the incidence of grade III or IV view (25.4% vs 11.5%, P = .01), increase the incidence of difficult intubation (12.3% vs 4.6%, P = .04), and decrease the rate of intubation on the first attempt (76.2% vs 85.4%, P = .02), respectively.

Conclusions: In this multicenter trial, the ramped position did not improve oxygenation during endotracheal intubation of critically ill adults compared with the sniffing position. The ramped position may worsen glottic view and increase the number of laryngoscopy attempts required for successful intubation.

Trial registry: ClinicalTrials.gov; No.: NCT02497729; URL: www.clinicaltrials.gov.

Keywords: endotracheal intubation; hypoxemia; randomized trial.

Manuscript Title: “A Multicenter, Randomized Trial of Ramped Position vs Sniffing Position During Endotracheal Intubation of Critically Ill Adults.”

Journal: Chest

PMID: 28487139