Comparison of ease of induction of spinal anaesthesia in sitting with legs parallel on the table versus traditional sitting position

Abstract

Introduction: it is sometimes difficult for some patients to optimally flex their hips and knees making traditional position for induction of spinal anaesthesia difficult to achieve. The ease of induction of spinal anaesthesia was compared with patients in sitting position with legs remaining on the table (new sitting method) versus legs placed on the side stool (traditional sitting method).

Methods: One hundred eligible elderly patients, aged between 65 and 80 years, scheduled for open prostactectomy, were prospectively randomized to 2 groups, LS and LT. Patients in (LS group) had their spinal anaesthesia induced in sitting position with their legs placed on the stool while patients in (LT group) had their spinal anaesthesia induced in sitting position with their legs remaning on the operating table. The primary endpoint was correct needle placement. Numbers of attempts, needle redirections and patients' comfort were determined to compare outcome in the two groups.

Results: More patients in LS group (78%) than those in the LT group (64%) had successful placement of spinal needle at first attempt (P = 0.12, RR = 1.6, 95% CI = 0.863-3.102). Needle redirections were similar at first attempt (52% versus 40%; P = 0.22). The groups were equivalent with respect to 100% overall success rate (P = 1.000). It took longer time to induce spinal anaesthesia in patients in LS group (240 vs 125s, p < 0.001). Patients in LT were more comfotable.

Conclusion: The 100% overall success rate was comparable. However, patients were generally more comfortable with their legs placed on the table.

Keywords: Spinal anaesthesia, elderly, spinal needle, bony contacts