PREVENTION OF HYPERTENSION DURING TRANS-SPHENOIDAL SURGERY - THE EFFECT OF BILATERAL MAXILLARY NERVE BLOCK WITH LOCAL-ANESTHETICS

Background: Severe cardiovascular responses are known to occur during trans-sphenoidal excision of the pituitary gland despite adequate dept h of anaesthesia. This study was undertaken to evaluate the effects of bilateral maxillary nerve block with local anaesthetics on the cardio vascular responses to various stimuli during this procedure. Methods: In a group of 32 patients, 5-10 mi of a mixture of bupivacaine 0.5% an d lignocaine 2% (1:1) was injected in the pterygopalatine fossa after induction of general anaesthesia. Seven control group patients did not receive any nerve block. In all the patients, general anaesthesia was induced with thiopentone and maintained with nitrous oxide-oxygen, pe ntazocine, boluses of thiopentone and halothane. Pancuronium was used for neuromuscular blockade. Results: In both the groups, maximum hyper tension occurred on opening the blades of the bivalve nasal speculum. In the study group, hypertensive response was significantly less follo wing nasal infiltration with adrenaline containing solution (10.26% in crease vs. 23.08% in the control group, P<0.05), nasal dissection (2.8 2% vs. 9.45%, P<0.01) and on application of the nasal speculum (14.93% vs. 35.16%, P<0.01). The effect on heart rate response was not signif icant.Conclusion: The described technique is a useful adjunct to gener al anaesthesia for suppressing the haemodynamic responses during trans -sphenoidal surgery.