Prevention of pain on injection with propofol: A quantitative systematic review

The best intervention to prevent pain on injection with propofol is unknown . We conducted a systematic literature search (Medline, Embase, Cochrane Li brary, bibliographies, hand searching, any language, up to September 1999) for full reports of randomized comparisons of analgesic interventions with placebo to prevent that pain. We analyzed data from 6264 patients (mostly a dults) of 56 reports. On average, 70% of the patients reported pain on inje ction. Fifteen drugs, 12 physical measurements, and combinations were teste d. With IV lidocaine 40 mg, given with a tourniquet 30 to 120 s before the injection of propofol, the number of patients needed to be treated (NNT) to prevent pain in one who would have had pain had they received placebo was 1.6. The closest to this came meperidine 40 mg with tourniquet (NNT 2.9) an d metoclopramide 10 mg with tourniquet (NNT 2.2). With lidocaine mixed with propofol, the best NNT was 2.4; with IV alfentanil or fentanyl, it was 3 t o 4. IV lidocaine before the injection of propofol was less analgesic. Temp erature had no significant effect. There was a lack of data for all other i nterventions to allow meaningful conclusions. The diameter of venous cathet ers and speed of injection had no impact on pain. Implications: IV lidocain e (0.5 mg/kg) should be given with a rubber tourniquet on the forearm, 30 t o 120 s before the injection of propofol; lidocaine will prevent pain in ap proximately 60% of the patients treated in this manner.