Comparative evaluation of the prolonged use of the cuffed oropharyngeal airway and the laryngeal mask airway in spontaneously breathing anaesthetizedpatients

The cuffed oropharyngeal airway (COPA) was compared with the laryngeal mask airway (LMA) with respect to airway quality and respiratory adverse events in 140 spontaneously breathing patients undergoing procedures of duration more than 1 h. Patients were allocated randomly to receive either a COPA (n =72) or a LMA (n=68) for airway management during anaesthesia induced with propofol and maintained with sevoflurane, nitrous oxide and oxygen. Groups were similar when comparing the first-time successful insertion rates (COPA : 94.5%, LMA: 95.6%), but airway manipulations (head tilt, chin lift, jaw t hrust) were reported more frequently in the COPA group, 27.8% vs. LMA, 4.4% ; P=0.0005. During the post-induction apnoeic period, all patients were ven tilated manually and although, mean (SD) leak pressure was lower in the COP A group (18 (4) cm H2O vs. LMA, 22 (3) cm H2O; P < 0.0001), the tidal volum es achieved did not differ in both groups: COPA, 9.5 (4) mL kg(-1) vs. LMA, 10.5 (4.5) mL kg(-1). The incidences of intra-operative coughing, gagging, laryngospasm, oxygen desaturation and hypercarbia were similar in both gro ups. Although both devices are equivalent with respect to the overall respi ratory problems during spontaneous breathing anaesthesia of intermediate or prolonged duration, the LMA was associated with fewer airway quality probl ems, suggesting that it is more efficacious in securing the airway.