Ho-Tai L M, Devitt J H, Noel A G, O'Donnell M P
Department of Anaesthesia, Sunnybrook Health Science Centre, University of Toronto, Ontario.
Can J Anaesth. 1998 Mar;45(3):206-11. doi: 10.1007/BF03012903.
To compare two airway management techniques, face mask (FM) with oropharyngeal airway and laryngeal mask airway (LMA), with respect to the effectiveness of positive pressure ventilation and airway maintenance.
After induction of anaesthesia, two airway management techniques (FM or LMA) and three peak pressures (20, 25 and 30 cm H2O) were randomly applied during controlled ventilation in 60 patients. Data collected included inspiratory and expiratory volumes and presence of gastro-oesophageal insufflation. Leak was calculated by subtracting the expiratory from the inspiratory volume, expressed as a fraction of the inspiratory volume.
Expiratory volumes (mean +/- SD) at 20, 25 and 30 cm H2O for LMA ventilation were 893 +/- 260, 986 +/- 276 and 1006 +/- 262 respectively, and for FM ventilation 964 +/- 264, 1100 +/- 268 and 1116 +/- 261. Leak fractions at 20, 25 and 30 cm H2O for LMA ventilation were 0.21 +/- 0.15, 0.24 +/- 0.18 and 0.26 +/- 0.18 respectively, and for FM ventilation 0.14 +/- 0.09, 0.14 +/- 0.09 and 0.12 +/- 0.08. The frequency of gastro-oesophageal insufflation was 1.6%, 5% and 5% for the LMA and 5%, 15% and 26.6% for the FM for ventilation pressures of 20, 25 and 30 cm H2O respectively which was greater with LMA use.
Ventilation was adequate in all patients using both techniques. Leak was pressure dependent and greater with LMA use. Most of the leak was vented to the atmosphere via the pharynx. Gastro-oesophageal insufflation was more frequent with ventilation using the face mask. LMA use with positive pressure ventilation would appear to be a better airway management method than the face mask.
比较两种气道管理技术，即面罩（FM）联合口咽通气道与喉罩气道（LMA）在正压通气有效性和气道维持方面的差异。
60例患者在麻醉诱导后，于控制通气期间随机应用两种气道管理技术（FM或LMA）和三种峰值压力（20、25和30 cm H₂O）。收集的数据包括吸气和呼气量以及胃食管充气情况。漏气量通过吸气量减去呼气量计算得出，并以吸气量的分数表示。
LMA通气在20、25和30 cm H₂O时的呼气量（均值±标准差）分别为893±260、986±276和1006±262，FM通气时分别为964±264、1100±268和1116±261。LMA通气在20、25和30 cm H₂O时的漏气分数分别为0.21±0.15、0.24±0.18和0.26±0.18，FM通气时分别为0.14±0.09、0.14±0.09和0.12±0.08。对于20、25和30 cm H₂O的通气压力，LMA导致胃食管充气的频率分别为1.6%、5%和5%，FM分别为5%、15%和26.6%，使用LMA时胃食管充气频率更高。
两种技术在所有患者中通气均充分。漏气与压力相关，使用LMA时漏气更多。大部分漏气通过咽部排至大气。使用面罩通气时胃食管充气更频繁。与面罩相比，使用LMA进行正压通气似乎是一种更好的气道管理方法。
