Comparison Of The Airway Seal Between Oro-pharyngo-laryngeal Airway Cap And Classic Laryngeal Mask Airway In Different Depth Of Muscle Relaxation

ObjectiveLaryngeal mask airway (LMA) has been used for intermittent positive pressure ventilation. Oro-Pharyngo-Laryngeal Airway Cap(OPLAC) is a new kind of disposal supraglottic airway device without cuff specially designed for Chinese people. To evaluate the influences of the depth of muscle relaxation on airway seal using OPLAC and Classic Laryngeal Mask Airway (CLMA) during radical mastectomy.MethodsSixty ASAⅠorⅡpatients aged 30-60 years, body mass index less than 30kg/m2 undergoing radical mastectomy were enrolled in the study. The patients were randomized to receive either OPLAC ventilation (group O) or CLMA ventilation (group C) (n=30 each), and we used the fiberoptic bronchoscopy to adjust positions. In group C, after insertion, the cuff pressure was set at 60cmH2O .Both groups used total intravenous anesthesia and intermittent positive pressure ventilation. The depth of muscle relaxation determined with TOF-Watch SX accelerometric monitor. The oropharyngeal leak pressure(OLP) was measured when the TOF ratio was 0 %( T1); 20 %( T2); 40 %( T3); 60 %( T4) and 80 %( T5). The incidence of gastric distension during the operation was recorded.ResultsAll patients were similar in age, body mass index and anesthesia time(P>0.05). There was no significant difference in OLP at T1– T5 between two groups. The OLP was decreased at T4-5 in group O and at T3-5 in group C as compared with the value at T1. There was no patient sufferded from gastric distension and other complications in both groups.ConclusionThe depth of muscle relaxation can affect airway seal using OPLAC and CLMA. We can get better sealing effect when there is better muscle relaxation. Although OPLAC does not have cuff, it can produce good airway seal when used for Chinese patients in different depth of muscle relaxation.