A randomized controlled trial found that high-flow nasal cannula oxygenation may reduce hypoxia incidence in patients with obesity undergoing sedated gastrointestinal endoscopy.
In the study, published in The BMJ and conducted in three tertiary hospitals in China, investigators analyzed the data from 984 patients, comparing high-flow nasal cannula (HFNC) oxygenation with standard nasal cannula oxygenation. Hypoxia (arterial oxygen saturation [SpO2] = 75%–90% for < 60 seconds) occurred in 2.0% of the patients in the HFNC oxygenation group vs 21.2% of those in the standard group (P < .001). Severe hypoxia (SpO2 < 75% or SpO2 75%–90% for > 60 seconds) was eliminated in the HFNC oxygenation group (0.0% vs 4.1%, P < .001). Subclinical respiratory depression (SpO2 = 90%–95%) was also significantly lower (5.6% vs 36.3%, P < .001).
Senior researcher Diansan Su, MD, PhD, of Renji Hospital at the Shanghai Jiao Tong University School of Medicine, and colleagues noted that HFNC oxygenation offered a safer alternative in patients with obesity undergoing sedation. Patients in the HFNC oxygenation group received 60 L/min oxygen at 100% concentration, whereas the standard group received 6 L/min. Propofol and low-dose sufentanil were used for sedation, with continuous oxygenation monitoring.
HFNC oxygenation also reduced the need for airway intervention—just 2.2% of the patients required jaw thrust maneuvers vs 21.1% of those in the standard group (P < .001). None of the patients in the HFNC oxygenation group required mask ventilation compared with 4.9% of those in the standard group. Adverse events, including bradycardia (3.4% vs 2.5%, P = .38), tachycardia (1.2% vs 2.1%, P = .29), and hypotension (4.2% vs 2.7%, P = .18), showed no statistically significant differences. The most common HFNC oxygenation–related event was mild dry mouth (2.8%), with no cases of barotrauma, nasal mucosal injury, or bleeding.
The investigators attributed HFNC oxygenation’s effectiveness to its ability to provide high oxygen concentrations, reduce dead space ventilation, and generate continuous positive airway pressure. However, the study excluded patients over 70 years and those with severe comorbidities (American Society of Anesthesiologists class ≥ III), highlighting the need for further research in broader populations.
"In patients with obesity, oxygenation via HFNC during sedated gastrointestinal endoscopy significantly reduced the incidences of hypoxia, subclinical respiratory depression, and severe hypoxia without increasing other adverse events," the study authors explained.
The findings could inform clinical guidelines as obesity rates and sedated endoscopic procedures continue to rise.
Full disclosures are available in the study.