Evaluation of efficacy of Valsalva maneuver for attenuating propofol injection pain: a prospective, randomized, single blind, placebo controlled study

Abstract

Background Pain on injection is a limitation with propofol use. The effect of the Valsalva maneuver on pain during propofol injection has not been studied. This maneuver reduces pain through the sinoaortic baroreceptor reflex arc and by distraction. We aimed to assess the efficacy of the Valsalva maneuver in reducing pain during propofol injection. Methods Eighty American Society of Anesthesiologists class I adult patients undergoing general anesthesia were enrolled and divided into two groups of 40 each. Group I (Valsalva) patients blew into a sphygmomanometer tube raising the mercury column up to 30 mmHg for 20 seconds, while Group II (Control) patients did not. Anesthesia was induced with 1% propofol immediately afterwards. Pain was assessed on a 10-point visual analog scale (VAS), where 0 represented no pain, and 10, the worst imaginable pain, and a 4-point withdrawal response score, where 0 represented no pain, and 3, the worst imaginable pain. Scores were presented as median (interquartile range). Results We analyzed the data of 70 patients. The incidence of pain was significantly lower in the Valsalva than in the control group (53% vs 78%, P = 0.029). The withdrawal response score was significantly lower in the Valsalva group (1.00 [0.00-1.00] vs 2.00 [2.00-3.00], P < 0.001). The VAS score was significantly lower in the Valsalva group (1.00 [0.00-4.00] vs 7.00 [6.25-8.00], P < 0.001). Conclusions A prior Valsalva maneuver is effective in attenuating injection pain due to propofol; it is advantageous in being a non-pharmacological, safe, easy, and time-effective technique.

Keywords

• distraction
• general anesthesia
• propofol
• valsalva maneuver
• visual analog scale
• withdrawal response score