Nasal mask outperforms traditional nasal cannula during gastroscopy procedures

In the United States alone, more than 6 million esophagogastroduodenoscopy operations are conducted each year, and more than 53% of endoscopies are currently performed under intravenous anaesthetic. Under intravenous anaesthetic, hypoxemia is common during gastroscopy. Although administering supplemental oxygen through a conventional nasal cannula is the current standard of treatment for most patients getting intravenous anaesthesia for gastroscopy, hypoxemia still occurs in more than 40% of patients.

Several treatments have been developed to lower the occurrence of hypoxemia during gastroscopy. High-flow nasal cannula (HFNC) oxygenation and the insertion of a nasopharyngeal catheter were previously shown to lower the incidence of hypoxemia during gastroscopy anaesthesia in limited studies. These approaches, however, need the use of supplementary oxygen devices or oxygen delivery systems, or they may result in adverse outcomes such as nasopharyngeal haemorrhage.

Investigators performed this randomised experiment to examine the effectiveness of nasal mask oxygen against normal nasal cannula during gastroscopy. Specifically, authors evaluated the hypothesis that nasal mask oxygen would result in a reduced incidence of hypoxemia during gastroscopy than a regular nasal cannula. The main outcome was the incidence of hypoxemia defined as an occurrence of SpO2 <90 percent .

During the study, 574 people who were going to have a gastroscopy under intravenous anaesthesia were enrolled. They were then randomly assigned to use either a nasal mask or a traditional nasal cannula to get oxygen. The main outcome was the occurrence of hypoxemia. The frequency of severe hypoxemia, duration of hypoxemia, minimum oxygen saturation, percentage of emergency airway management, length of surgery, recovery time, and anaesthetist and gastroenterologist satisfaction, as well as other adverse events, were all secondary outcomes (including cough, hiccups, nausea and vomiting, reflux, aspiration, and laryngospasm).

The investigation comprised a total of 565 patients: 282 with nasal cannulas and 283 with nasal masks. Hypoxemia occurred at a lower rate (18.0 percent) in the nasal mask group than in the nasal cannula group (27.7 percent; relative risk [RR] = 0.65; 95 percent confidence interval [CI], 0.48–0.89; P =.006), and hypoxemia lasted a median of 18.0 seconds (interquartile range, 10.0–38.8) in the nasal mask group and 32.5 seconds (20.0–53.5) in the nasal cannula group (median difference The percentage of patients needing emergency airway care was considerably lower (8.8 percent) in the nasal mask group than in the nasal cannula group (19.1 percent; RR, 0.46; 95 percent confidence interval, 0.30–0.73; P.001). There was no difference in the total incidence of other adverse events between the two groups (nasal mask 20.8 percent; nasal cannula 17.0 percent; risk ratio, 1.23; 95 percent confidence interval, 0.87–1.73; P =.25). Comfort was greater with the nasal mask than with the nasal cannula from the viewpoints of anaesthetists (96.1% for nasal mask versus 84.4% for nasal cannula; RR, 1.14; 95% CI, 1.08–1.20; P < .001) and gastroenterologists (95.4% for mask versus 81.9% for cannula; RR, 1.17; 95% CI, 1.10–1.24; P < .001). Between the two groups, there were no significant differences in the frequency of severe hypoxemia, minimum oxygen saturation, operation duration, or recovery time.

The authors of this research used a baby mask to provide oxygen through the nose and discovered that this nasal mask was an effective way to lower the incidence of hypoxemia. When compared to conventional nasal cannula oxygenation, nasal mask oxygenation resulted in a considerably reduced incidence of hypoxemia (18 percent vs 27.7 percent ). Furthermore, when compared to the nasal cannula group, nasal mask oxygenation significantly decreased the proportion of patients requiring emergency airway management (8.8 percent vs 19.1 percent) and increased anesthesiologists' and gastroenterologists' satisfaction, without increasing the incidence of other adverse events.

Reference –

Chen, Dong Xu MD*; Yang, Hui MD*; Wu, Xi Ping MM†; Niu, Wang MD*; Ding, Lin MD*; Zeng, Huo Lin MD*; Li, Qian MD* Comparison of a Nasal Mask and Traditional Nasal Cannula During Intravenous Anesthesia for Gastroscopy Procedures: A Randomized Controlled Trial, Anesthesia & Analgesia: March 2022 - Volume 134 - Issue 3 - p 615-623

doi: 10.1213/ANE.0000000000005828