Anaesthesia for thermocoagulation of the trigeminal ganglion

The anaesthetic requirement for thermocoagulation of the trigeminal ganglion is unusual, in that it calls for an anaesthetic depth from which the patient can be easily aroused. In our quest for a suitable technique of anaesthesia, using drugs available in India, a combination of haloperidol and pentazocine was found to provide adequate surgical conditions in terms of pain relief and patient cooperation. A fixed dose of 5 mg of haloperidol was followed by increments of pentazocine, depending on the patient's need. The insertion of the needle, and the thermocoagulation of the trigeminal ganglion was associated with marked increase in blood pressure and cardiac arrhythmias. Critical evaluation of the results showed that 0.08 mgkg-1 of haloperidol and 1 mgkg-1 of pentazocine, should be given before the needle is introduced.