Comparison of haemodynamic changes in patients undergoing unilateral and bilateral spinal anaesthesia

To assess the haemodynamic changes in patients receiving unilateral and bilateral spinal anaesthesia with their pre-anaesthesia recordings.

Quasi-experimental study.

Main Operation Theater, Liaquat National Hospital, Karachi, from May 2006 to February 2007.

Sixty patients meeting the inclusion criteria were randomly allocated in two groups of 30 patients each. One and a half ml of 0.75% hyperbaric bupivacaine was injected with free flow of cerebrospinal fluid using a 23 gauge quincke needle. Lumbar puncture was performed in the sitting position at 3 - 4 or 4 - 5 lumbar interspace. Patients were then assigned to the supine or lateral decubitus position for 10 minutes. Heart rate, systolic, mean and diastolic blood pressures of patients were recorded with their pre-anaesthesia readings in the 1st, 5th, 15th, 30th and then at every 15th minute till the end of procedure. Recovery room readings were also taken.

The systolic, mean and diastolic blood pressure changes were significant in both groups. But from 1st minute to recovery room, statistically significant difference (p < 0.05) was found at each time interval, the unilateral groups (group A) being more stable with respect to pre-anaesthesia readings. The decrease in heart rate was comparable in both groups.

Unilateral spinal anaesthesia was associated with a more stable cardiovascular profile, therefore, it is a valuable technique for high risk patients.