RESUMO
The haemodynamic changes encountered in spinal anaesthesia are directly related to the extent of sympathetic block and can be decreased by restricting the block to unilateral sympathetic chain. This prospective quasi experimental study compared the changes in heart rate and blood pressure in unilateral and bilateral spinal anaesthesia to demonstrate that unilateral block caused less haemodynamic changes. Sixty ASA I or II patients aged 20 - 60 years for elective inguinal herniorrhaphy were randomly divided into two groups: group - A [unilateral] and group - B [bilateral]; each having 30 patients. Hyperbaric bupivacaine [15 mg] was injected intrathecally in lateral position. Group A patients were kept in lateral position with surgical side down for 10 minutes. In group B, patient's position was immediately changed to supine. Blood pressure and heart rate were recorded prior to and at every 5 - minute intervals after spinal anaesthesia for a duration of 30 minutes. Chi-square and t-test were applied. Frequency of hypotension was 6.7% in group A and 60% in group B [p = 0.00]. Frequency of bradycardia was 6.7% in group A vs. 10% in group B [p = 0.50] while the frequency of tachycardia was 3.3% in group A and 16% in group B [p = 0.09]. Frequency of hypotension was significantly less in unilateral as compared to bilateral spinal anaesthesia