Department of General Anaesthesia, Indraprastha Apollo Hospital, New Delhi, India.
Department of Anaesthesia, Lady Hardinge Medical College, Shaheed Bhagat Singh Marg, New Delhi, India.
J Clin Anesth. 2015 Aug;27(5):396-400. doi: 10.1016/j.jclinane.2015.03.004. Epub 2015 Apr 30.
The anesthetic management of patients with morbid obesity is challenging. There is no consensus on the routine use of aspiration prophylaxis in morbidly obese patients undergoing elective surgery.
The aim of this study is to assess the risk of pulmonary aspiration and effect of premedication with ranitidine and metoclopramide on gastric pH and volume in morbidly obese and lean patients.
Gastric volume and pH were measured in 3 groups of 20 patients each: group I (lean, no aspiration prophylaxis), group II (morbidly obese, no aspiration prophylaxis), and group III (morbidly obese; tablet ranitidine, 150 mg; and tablet metoclopramide, 10 mg administered the night before and 2 hours before surgery). Patients with critical gastric volume >25 mL and critical pH <2.5 (Roberts and Shirley criteria) were considered to be at risk for pulmonary aspiration.
The percentage of patients with gastric volume >25 mL and pH <2.5 was 5%, 30%, and 0% in groups I, II, and III, respectively. Statistically significant difference existed between groups I and II (P = .04) and groups II and III (P = .006). Premedicated morbidly obese and lean patients were comparable (P = .46).
Morbidly obese patients undergoing elective surgery are at a higher risk for regurgitation and pulmonary aspiration when compared with lean patients. Preoperative aspiration prophylaxis decreases gastric volume and increases gastric pH and thus should be routinely prescribed.
病态肥胖患者的麻醉管理具有挑战性。对于择期手术的病态肥胖患者，常规使用吸引预防措施尚无共识。
本研究旨在评估胃内 pH 值和容量在病态肥胖和正常体重患者中的风险，并评估雷尼替丁和甲氧氯普胺预处理对胃内 pH 值和容量的影响。
将 3 组 20 例患者的胃容量和 pH 值进行了测量：组 I（正常体重，无吸引预防措施）、组 II（病态肥胖，无吸引预防措施）和组 III（病态肥胖；术前晚和术前 2 小时给予雷尼替丁片剂 150mg 和甲氧氯普胺片剂 10mg）。如果胃容量>25ml 和 pH 值<2.5（罗伯茨和雪莉标准），则认为存在发生肺吸入的风险。
胃容量>25ml 和 pH 值<2.5 的患者百分比分别为 5%、30%和 0%，组 I、II 和 III 之间存在统计学差异（P =.04）和组 II 和 III（P =.006）。预先用药的病态肥胖和正常体重患者之间无差异（P =.46）。
与正常体重患者相比，择期手术的病态肥胖患者发生反流和肺吸入的风险更高。术前预防措施可降低胃容量，增加胃内 pH 值，因此应常规应用。
