Unilateral versus bilateral spinal anaesthesia in geriatric patients undergoing hemiarthroplasty: a comparative study

Introduction
Conventional bilateral spinal anaesthesia can produce haemodynamic alterations that can be detrimental to geriatric patients. Unilateral spinal anaesthesia produces predominant blockade on the operated side, thereby reducing the incidence of hypotension. There is a scarcity of comparative studies evaluating the effects of unilateral spinal anaesthesia in the elderly population. Therefore, we conducted this study to compare the effects of unilateral and bilateral spinal anaesthesia in geriatric patients.

Material and methods
A prospective, parallel group, randomized, controlled study was conducted on 72 patients of age 60–85 years, ASA physical status I and II undergoing hemiarthroplasty under spinal anaesthesia. Patients were randomly allocated to two groups: patients in group U (n = 36) received unilateral spinal anaesthesia, those in group B (n = 36) received bilateral spinal anaesthesia. All patients received 1.5 mL of hyperbaric bupivacaine (0.5%) and 0.5 mL of fentanyl intrathecally in the lateral decubitus position. Patients in group B were turned to the supine position and those in group U maintained the lateral decubitus position for 15 minutes. Intraoperative and postoperative haemodynamic parameters, Bromage score and sensory block height were compared.

Results
Hypotension in group B patient was more pronounced compared to group U. There was no significant difference in the Bromage score and the number of patients reaching T10 sensory block height on the operated side between the two groups. The Bromage score and the number of patients reaching T10 sensory block height on the non-operated side were higher in group B.

Conclusions
In geriatric patients unilateral spinal anaesthesia produces predominant motor and sensory block on the operated side with less hypotension.