Background

Obesity is a risk factor for airway-related incidents during anaesthesia. High-flow nasal oxygen has been advocated to improve safety in high-risk groups, but its effectiveness in the obese population is uncertain. This study compared the effect of high-flow nasal oxygen and low-flow facemask oxygen delivery on duration of apnoea in morbidly obese patients.

Methods

Morbidly obese patients undergoing bariatric surgery were randomly allocated to receive either high-flow nasal (70 L min⁻¹) or facemask (15 L min⁻¹) oxygen. After induction of anaesthesia, the patients were apnoeic for 18 min or until peripheral oxygen saturation decreased to 92%.

Results

Eighty patients were studied (41 High-Flow Nasal Oxygen, 39 Facemask). The median apnoea time was 18 min in both the High-Flow Nasal Oxygen (IQR 18–18 min) and the Facemask (inter-quartile range [IQR], 4.1–18 min) groups. Five patients in the High-Flow Nasal Oxygen group and 14 patients in the Facemask group desaturated to 92% within 18 min. The risk of desaturation was significantly lower in the High-Flow Nasal Oxygen group (hazard ratio=0.27; 95% confidence interval [CI], 0.11–0.65; P=0.007).

Conclusions

In experienced hands, apnoeic oxygenation is possible in morbidly obese patients, and oxygen desaturation did not occur for 18 min in the majority of patients, whether oxygen delivery was high-flow nasal or low-flow facemask. High-flow nasal oxygen may reduce desaturation risk compared with facemask oxygen. Desaturation risk is a more clinically relevant outcome than duration of apnoea. Individual physiological factors are likely to be the primary determinant of risk rather than method of oxygen delivery.

Clinical trial registration

NCT03428256.

中文翻译：

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病态肥胖中的呼吸暂停氧合：一项比较面罩和高流量鼻氧输送的随机对照试验

背景

肥胖是麻醉期间气道相关事件的危险因素。一直提倡高流量经鼻吸氧以提高高危人群的安全性，但其在肥胖人群中的有效性尚不确定。本研究比较了高流量经鼻吸氧和低流量面罩吸氧对病态肥胖患者呼吸暂停持续时间的影响。

方法

接受减肥手术的病态肥胖患者被随机分配接受高流量鼻腔 (70 L min ^-1 ) 或面罩 (15 L min ^-1 ) 氧气。麻醉诱导后，患者窒息 18 分钟或直至外周血氧饱和度降至 92%。

结果

研究了 80 名患者（41 名高流量鼻氧，39 名面罩）。高流量鼻氧（IQR 18-18 分钟）和面罩（四分位间距 [IQR]，4.1-18 分钟）组的中位呼吸暂停时间均为 18 分钟。高流量鼻氧组的 5 名患者和面罩组的 14 名患者在 18 分钟内饱和度降低至 92%。高流量鼻氧组的去饱和风险显着降低（风险比 = 0.27；95% 置信区间 [CI]，0.11–0.65；P = 0.007）。

结论

在有经验的人看来，病态肥胖患者可能会出现呼吸暂停氧合，大多数患者在 18 分钟内不会出现氧饱和度下降，无论是高流量经鼻还是低流量面罩供氧。与面罩吸氧相比，高流量经鼻吸氧可降低饱和度降低风险。与呼吸暂停持续时间相比，去饱和风险是更具临床相关性的结果。个体生理因素可能是风险的主要决定因素，而不是氧气输送方法。

临床试验注册

NCT03428256。