Mechanisms of “Cough-Trick” for Pain Relief during Venipuncture: An Experimental Crossover Investigation in Healthy Volunteers

Figure 4

Pain intensity during all conditions and investigations. Pain intensities at venipuncture (VP) were assessed on a 100 mm visual analogue scale (VAS-100). Normally distributed data from investigations 1 and 2 are presented as mean and standard error of the mean. Nonparametric data from investigation 3 median are presented as median, interquartile range, and minimum and maximum values for each condition; circles within the boxes are the mean values of pain intensity. Cough-trick (CT) was performed simultaneously to the VP. Weak distraction: participants squeezed a rubber ball with the nonpunctured hand during the VP procedure. Strong distraction: participants manually inflated the tourniquet, placed on the arm at which VP was performed, to a pressure of 200 mmHg and hold it attentively during VP. Without intervention: VP was performed without pain relief CT intervention prior to the administration of nonselective opioid receptor antagonist naloxone (NX). Cough-trick under NX: VP with CT was performed 30 minutes after naloxone infusion. for the comparison of cough-trick vs. weak distraction with Student’s t-test for paired samples.