Spinal and supra-spinal modulation of propofol injection pain by rubbing and distraction: a randomized,...

Propofol, an intravenous (IV) anesthetic drug, is associated with injection pain if administered in its standard formulation without intervention. Pain transmission can be modulated or inhibited at the spinal cord dorsal horn cell level or at the supra-spinal levels. In this trial, rubbing and distraction were combined to evaluate their effects on propofol injection pain (PIP).

One hundred thirty-five patients were randomized equally into a lidocaine (L) group (received propofol mixed with 40 mg lidocaine before its IV injection), a rubbing distraction (RD) group (rubbing was applied starting from the IV injection site extending to the elbow, and distraction was done by asking the patients to watch a 10-second mobile video to answer a question related to this video), and a saline (S) group (received IV propofol mixed with 2 mL saline and not preceded by any drug). When patients received 0.5 mg/kg (1/4 of the total propofol dose) over five seconds, pain degree was evaluated using a 0-3 verbal rating scale (VRS) (0=no pain, 1=mild, 2=moderate, 3=severe pain]. The incidence and severity of PIP and the incidence of pain recall at 1h after surgery were recorded.

PIP incidence was significantly lower in L and RD groups as compared to group S (P<0.001). Group L and group RD patients had significantly lower VRS pain scores compared with group S patients, P<0.001. Pain recall after surgery was significantly lower in RD group as compared to S group; P=0.003.

Rubbing and distraction could decrease the incidence and severity of PIP comparable to the IV lidocaine with a significantly lower incidence of postoperative recall.