[Effectiveness and safety of unilateral spinal anaesthesia]

The purpose of the study was to evaluate the effectiveness and safety of unilateral spinal anaesthesia and to compare this technique to the commonly used bilateral technique in a prospective, controlled, randomized study.

Fifty-four ASA I-III adult patients, of both sexes, aged 18-75 years, and scheduled for elective unilateral surgery, were randomly allocated into two groups: a unilateral spinal anaesthesia group (group B, n=27, to receive 0.5% hyperbaric bupivacaine, 1.2 mL+0.1 mL per every 10 cm over 170 cm height); and a bilateral spinal anaesthesia group (group K, n=27, to receive 0.5% bupivacaine 2.4 mL+0.2 mL per every 10 cm over 170 cm height). The statistical analysis included haemodynamic parameters and side-effects. The t-test for independent trials, test for two structure indexes and chi2 test were used.

All blocks were fully effective. Mean arterial blood pressure was significantly lower in the K group. Heart and respiratory rates did not differ between the groups. The total number of side effects (hypotension, bradycardia, apnoea) requiring intervention was similar in both groups.

Unilateral spinal anaesthesia is safe. The dose of bupivacaine is lower and haemodynamic stability is better. The technique is more time consuming, compared to standard spinal anaesthesia and the patient's cooperation is essential.