Double blind randomized control trial to evaluate the efficacy of ketoprofen patch to attenuate pain during venous cannulation

Background Venipuncture pain is an uncomfortable suffering to the patient. It creates anxiety, fear and dissatisfaction. The ketoprofen transdermal patch is a proven treatment for musculoskeletal and arthritic pain. We planned this study to evaluate the efficacy of the ketoprofen patch to reduce venipuncture pain. Methods Two hundred adult patients, aged 18-60 years, of either sex, ASA grade I or II, were enrolled. Presuming that therapy would decrease venipuncture pain by 30%, a power calculation with α = 0.05 and β = 0.80 required enrollment of at least 24 patients into each group. However, 100 patients in each group were recruited. Group I (Control) received a placebo patch; Group II (Ketoprofen) received a 20 mg ketoprofen patch. A selected vein on the dorsum of the patient's non-dominant hand was cannulated with 18 g intravenous cannula 1 h after the application of the respective patch. Assessment of pain was done by a 10 cm visual analogue scale (VAS) of 0-10, where 0 depicts "no pain" and 10 is "the worst imaginable pain". The venipuncture site was assessed for the presence of skin erythema, swelling and rashes at 12 h, 24 h and at the time of decannulation. Results Incidence of pain was 100% (94/94) in the control group as compared to 93% (85/91) in the ketoprofen group. The severity of the venipuncture pain was 6 (2) and 2 (2) for control and ketoprofen groups respectively (P < 0.05). Conclusions Application of a ketoprofen patch at the proposed site of venipuncture one hour before the attempt is effective and safe for attenuating venipuncture pain.