RESUMEN
Thirty elderly males [over 60 years], ASA physical status I and II patients scheduled for elective inguinal hernia repair were randomly assigned [n=15per group] to receive premedication with either saline 3 ml [Group I], or dexmedetomidine Hcl 0.5micro/kg diluted in 3 ml saline [Group II] given intramuscular, 45 minutes before induction of spinal anaesthesia. During spinal anaesthesia, heart rate [HR] significantly decreased in the dexmedetomdine group compared to the control group. Although systolic arterial blood pressure [SABP] decreased significantly in both groups. no significant difference was recorded between dexmedetomidine and control groups. Core body temperature showed significant decrease in both groups without statistical significant differences between them. During and after spinal anaesthesia shivering incidences were significantly less in the dexmedetomidine group in comparison to the control group. In conclusion, when compared to control elderly patients under spinal anaesthesia, single dose [0.5micro/kg] of intramuscular dexmedetomidine premedication provided minimal changes in patient's haemodynamics. This small dose did not attenuate nor exaggerate redistribution of core hypothermia. While core temperature decreased in both groups, there was a lower incidence of shivering in the dexmedetomidine group