Spontaneous ventilation with propofol and remifentanil infusions for transurethral procedures

K Papilas, M. Mitselou, L. Papaspyrou, A. Bairaktari, M. Kokolaki,

E. Nazlidou, M. Vafiadou. Sismanoglion Hospital, Athens, Greece

 

The majority of transurethral procedures are of short duration and a lot of them are performed as day cases. An anaesthetic technique employing propofol and remifentanil would seem particularly suitable. We have initially investigated the use of propofol and remifentanil for spontaneous ventilation1, with and without the addition of nitrous oxide.

           

Material and Methods

28 ASA I-II patients participated in the study. Following preoxygenation for two minutes, remifentanil was administered as a bolus of 0.15 mg kg-1 and the infusion set at 0.05 mg kg-1 min-1. Two minutes afterwards, propofol 2.5 mg kg-1 was administered and the infusion started at 6 mg kg-1 h-1.

 

Following insertion of the laryngeal mask, 12 patients breathed 30% O2 in air and 16 patients 40% O2 in N2O. The operation started within 2 min and return of spontaneous ventilation and movement were observed. The patients were ventilated manually if SaO2 < 94% or EtCO2 > 55 mmHg.

           

Results

No patient moved at the start of the operation, while nine required a few manual breaths. Within 6 minutes from induction, all patients breathed spontaneously. Five patients in the air group moved in response to surgery and propofol 20 mg was given, with a bolus of 0.1 mg kg-1 remifentanil while the infusion was set to 0.1 mg kg-1 min-1. Ventilation was inadequate in two of these patients and another two required more boluses of propofol. In the N2O group, three patients required the same course of action, but no further boluses of propofol or manual ventilation.

           

In total, eight patients received atropine for bradycardia. Recovery and extubation occurred 4 to 7 min from the end of the infusions and administration of 100% O2. No patient reported intraoperative awareness.

 

Conclusion

Although the number of patients in this initial study is small, it seems that for TUR procedures, adequate anaesthesia with maintenance of spontaneous ventilation and prompt recovery, can be achieved using 60% N2O with a rather low dose infusion of 6 mg kg-1 ­h-1 propofol and 0.05 – 0.1 mg kg-1 min-1 remifentanil.

 

Reference:

1.       Peacock JE et al: Remifentanil in combination with propofol for spontaneous ventilation anaesthesia. Br J Anaesth 80 (4): 509-11, 1998.