Efficacy of ShotBlocker device versus vapocoolant spray for spinal needle pain relief during spinal anaesthesia in elective caesarean section - A randomised controlled trial

Background and Aims: Apprehension of pain due to a spinal needle is often a cause of anxiety and refusal. ShotBlocker provides non-painful physical stimulation, inhibiting pain perception. The vapocoolant spray contains ethyl chloride vapours, rapidly raising the skin temperature and hampering the transmission of noxious stimuli. The present study compared the effectiveness of the ShotBlocker device and the vapocoolant spray in reducing spinal needle-associated pain in primigravida women undergoing elective lower-segment caesarean section (LSCS). Methods: We enroled 144 primigravida women undergoing elective LSCS and were randomised to Group SB (the ShotBlocker device was firmly pressed over the skin, and the spinal needle was inserted through its slit), Group V (the vapocoolant spray was applied at the puncture site before spinal needle insertion), and Group C (received local infiltration before spinal anaesthesia (SA)). The groups were compared for needle-associated pain and patient satisfaction using a 10-point visual analogue scale (VAS) and a 3-point Likert scale. Results: The mean (standard deviation) [95% confidence interval (CI)] VAS scores of Group SB 3.85 (0.74) [3.64, 4.07] and Group V 3.04 (0.74) [2.83, 3.26] were significantly lower than that of Group C 5.19 (0.92) [3.28, 3.62]). On the Likert scale, the maximum number of patients in the vapocoolant group (64.6%) responded satisfactorily, while in the control group, the majority (62.5%) of participants responded dissatisfied (P < 0.001). Conclusion: Both the ShotBlocker and vapocoolant spray reduce needle puncture-associated pain before SA in primigravida patients undergoing elective LSCS. However, the vapocoolant spray is more beneficial in reducing spinal needle-associated pain than the ShotBlocker device.