Advantageous effects of dexmedetomidine on haemodynamic and recovery responses during extubation for intracranial surgery

Abstract

The anaesthetic method for intracranial neurosurgery must provide haemodynamic stability on emergence and allow early evaluation of the neurological status. In this study, we examined the effects of the alpha-2 agonist dexmedetomidine given at the end of the procedure to prevent hyperdynamic responses during extubation and to allow a comfortable and high-quality recovery. Forty ASA I-III patients, aged between 18 and 75 yr, having elective intracranial surgery, were divided into two random groups. Standard procedures and drugs were used for monitoring, induction and maintenance. Isoflurane was reduced by 50% 5 min before the end of the surgery, and in Group I dexmedetomidine 0.5 microg kg(-1) and in Group II 20 mL of 0.9% NaCl were administrated intravenously over 60 s. Systolic, diastolic and mean arterial pressures, and heart rate were recorded before intravenous administration and also at 1, 3 and 5 min after administration, 1 min before extubation, during extubation, 1, 3, 5, 10, 15, 20 and 30 min after extubation. Duration of extubation and recovery were noted, and the quality of extubation was evaluated on a 5-point scale. Mean arterial pressure and heart rate were significantly higher in Group II than in Group I (P < 0.01). There were no statistically significant differences between groups regarding the duration of extubation and recovery (P > 0.05). Extubation quality score of all the patients were 1 in Group I and in Group II, the quality scores were 1 for 35%, 2 for 45% and 3 for 20% of the patients (P < 0.001). None of the patients in Group I and Group II showed respiratory depression, nausea or vomiting. Without interfering in recovery time, dexmedetomidine 0.5 microg kg(-1) administered 5 min before the end of surgery stabilizes haemodynamics, allows easy extubation, provides a more comfortable recovery and early neurological examination following intracranial operations.