Zoremba M, Aust H, Eberhart L, Braunecker S, Wulf H
Department of Anaesthesia, University of Marburg, Baldingerstrasse, Marburg, Germany.
Acta Anaesthesiol Scand. 2009 Apr;53(4):436-42. doi: 10.1111/j.1399-6576.2008.01882.x. Epub 2009 Feb 18.
Obesity is a well-established risk factor for perioperative pulmonary complications. Anaesthetic drugs and the effect of obesity on respiratory mechanics are responsible for these pathophysiological changes, but tracheal intubation with muscle relaxation may also contribute. This study evaluates the influence of airway management, i.e. intubation vs. laryngeal mask airway (LMA), on postoperative lung volumes and arterial oxygen saturation in the early postoperative period.
We prospectively studied 134 moderately obese patients (BMI 30) undergoing minor peripheral surgery. They were randomly assigned to orotracheal intubation or LMA during general anaesthesia with mechanical ventilation. Premedication, general anaesthesia and respiratory settings were standardized. While breathing air, we measured arterial oxygen saturation by pulse oximetry. Inspiratory and expiratory lung function was measured preoperatively (baseline) and at 10 min, 0.5, 2 and 24 h after extubation, with the patient supine, in a 30 degrees head-up position. The two groups were compared using repeated-measure analysis of variance (ANOVA) and t-test analysis. Statistical significance was considered to be P<0.05.
Postoperative pulmonary mechanical function was significantly reduced in both groups compared with preoperative values. However, within the first 24 h, lung function tests and oxygen saturation were significantly better in the LMA group (P<0.001; ANOVA).
In moderately obese patients undergoing minor surgery, use of the LMA may be preferable to orotracheal intubation with respect to postoperative saturation and lung function.
肥胖是围手术期肺部并发症公认的危险因素。麻醉药物以及肥胖对呼吸力学的影响是这些病理生理变化的原因，但气管插管加肌肉松弛也可能起作用。本研究评估气道管理，即气管插管与喉罩气道（LMA），对术后早期肺容量和动脉血氧饱和度的影响。
我们前瞻性研究了134例接受外周小手术的中度肥胖患者（BMI 30）。在全身麻醉机械通气期间，他们被随机分配接受经口气管插管或LMA。术前用药、全身麻醉和呼吸设置均标准化。在呼吸空气时，我们通过脉搏血氧饱和度测定法测量动脉血氧饱和度。在患者仰卧位、头抬高30度的情况下，于术前（基线）以及拔管后10分钟、0.5小时、2小时和24小时测量吸气和呼气肺功能。使用重复测量方差分析（ANOVA）和t检验分析对两组进行比较。统计学显著性被认为是P<0.05。
与术前值相比，两组术后肺机械功能均显著降低。然而，在术后24小时内，LMA组的肺功能测试和血氧饱和度明显更好（P<0.001；ANOVA）。
在接受小手术的中度肥胖患者中，就术后饱和度和肺功能而言，使用LMA可能优于经口气管插管。
