环状软骨压迫对食管引流型喉罩通气道插入操作和通气功能的影响

目的 评价环状软骨压迫(CP)对食管引流型喉罩通气道(PLMA)插入操作和正压通气功能的影响.方法 50例按美国麻醉医师协会(ASA)标准身体状态分级为Ⅰ级的择期整形外科手术患者被纳入研究.静脉麻醉诱导后,于CP下插入PLMA,保留专用引导器并将通气罩内压充气至60 cm H2O(1 cm H2O=0.098 kPa).观察肺通气满意度,测定气道密封压,并采用光导纤维支气管镜(FOB)评价通气罩的解剖位置.暂时终止CP,采用专用引导器进一步推送PLMA到达理想位置,并重新调整通气罩内压至60 cm H2O.再次评价上述指标,并记录CP下和非CP下正压通气时的呼潮气量和吸气峰压,观察经PLMA插入胃管的情况并评价引流管解剖位置的FOB评分.结果 与在CP下插入PLMA比较,在临时解除CP并进一步推送PLMA后,肺通气满意度(良好和尚可为50例比14例)、气道密封压(27±7)cm H2O比(21±7)cm H2O]和通气罩解剖位置的FOB评分均显著改善(P均＜0.05).在将PLMA推送至理想位置后,虽然在CP和非CP时的正压通气呼潮气量差异无显著性,但CP时的吸气峰压(28±5)cm H2O]却显著高于非CP时(14±2)cm H2O,P＜0.05].结论 CP可阻碍将PLMA插入到理想位置,在暂时终止CP的情况下,采用专用引导器可将PLMA插入到理想位置,而且CP可显著增加正压通气的吸气峰压.

Influence of pressure on cricoid on insertion ProSeal laryngeal mask airway and ventilation function

OBJECTIVE: To assess the influence of cricoid pressure (CP) on insertion and ventilation function of ProSeal laryngeal mask airway (PLMA). METHODS: Fifty adult patients with American Society of Anesthesiologists (ASA) physical status categoryI, scheduled for elective plastic surgery were studied. After induction of intravenous anesthesia, the PLMA was inserted using an introducer under CP and the intracuff pressure was set to 60 cm H(2)O (1 cm H(2)O=0.098 kPa) with the introducer in place. The content degree of lung ventilation, airway seal pressure and anatomic position of the cuff were assessed. Then CP was temporary terminated, the PLMA was further advanced to the ideal position and the intracuff pressure was readjusted to 60 cm H(2)O. The above-mentioned assessments were re-performed, and the expiratory tidal volume and peak inspiratory pressure during positive-pressure ventilation (PPV) with and without CP were recorded. The gastric tube placement through the PLMA was observed, anatomical position of the drain tube was also scored by fiberoptic examination. RESULTS: After the PLMA was further advanced to the ideal position under temporary termination of CP, lung ventilation content degree (good: acceptable=50:14 cases), airway seal pressure (27+/-7) cm H(2)O vs. (21+/-7) cm H(2)O] and fiberoptic score of anatomical position of cuff were significantly improved compared with those after PLMA insertion under CP (P<0.05). The expiratory tidal volume during PPV was not significantly different between with and without CP, but the peak inspiratory pressure increased from (14+/-2) cm H(2)O without CP to (28+/-5) cm H(2)O with CP, and there was statistically significant difference (P<0.05). In all patients, gastric tube placement through the PLMA was successful with single attempt and correct anatomical position of the drain tube was confirmed by fiberoptic examination. CONCLUSION: The CP can impede the insertion of PLMA into the ideal position. The PLMA is still able to be advanced to the ideal position with a special introducer under temporary termination of CP. After the PLMA is advanced to the ideal position, the CP produces a significant increase in the peak inspiratory pressure during PPV.