HEMODYNAMIC AND ELECTROENCEPHALOGRAPHIC RESPONSE TO INSERTION OF A CUFFED OROPHARYNGEAL AIRWAY - COMPARISON WITH THE LARYNGEAL MASK AIRWAY

We have compared the cuffed oropharyngeal airway (COPA), a modified Gu edel airway device with a specially designed cuff at its distal end, w ith the laryngeal mask airway (LMA), on haemodynamic and electroenceph alographic (EEG) responses to insertion. In addition, we examined the haemodynamic and EEG changes during initiation of the effect-compartme nt controlled infusion. We studied 35 female patients undergoing ambul atory gynaecological surgery allocated randomly to received an LMA or COPA to manage the airway. After premedication with midazolam 0.03 mg kg(-1) i.v. and low-dose alfentanil (0.01 mg kg(-1)), anaesthesia was induced and maintained with propofol, using an effect-compartment cont rolled infusion set at an effect-site concentration of 4 mu g ml(-1). After intercompartmental equilibration, the LMA (group I) or COPA (gro up II) was inserted and haemodynamic (arterial pressure, heart rate) a nd EEG (bispectral index (BIS)) responses to insertion studied. The ef fect-compartment controlled infusion of propofol caused only mild haem odynamic changes during induction. Changes in arterial pressure and he art rate after insertion were similar in both groups and not significa ntly different from baseline values before insertion. Changes in BIS a fter insertion were minor and similar between groups.