Is lidocaine-prilocaine cream (EMLA) always useful for venous puncture in preoperative autologous blood donation?

PURPOSE

The goal of the present study was to evaluate in adults the benefit of the Eutectic Mixture of Local Anesthetics (EMLA) for preoperative autologous blood donation.

METHODS

Twenty-six adult patients requiring three blood samples were studied. The pain of venipuncture was assessed by the patient using a 100 mm Visual Analogue Scale (VAS) and a four-category Verbal Rating Scale (VRS). The first puncture was performed without anaesthesia, as a "reference puncture". The second and third punctures were performed with EMLA and placebo in a double-blind cross-over randomization. For statistical analysis, the patients were allocated to two groups according to the VAS scores of the reference puncture: (Group 1) VASref < 20 mm; (Group 2) VASref > or = 20 mm.

RESULTS

For the whole 26 patients, the VAS and the VRS pain scores were lower for EMLA puncture than for both the placebo and reference punctures (P < 0.05). Twenty patients had a VASref < 20 mm and six patients a VASref > or = 20 mm. In Group 1, there was no difference between EMLA and placebo for both the VAS and VRS scores. In contrast, in Group 2, the VAS score was lower for EMLA than for both the placebo and the reference punctures (respectively 11 +/- 7.1, 28.9 +/- 7.9, 29.1 +/- 6.4; P < 0.01); the VRS score was also lower for EMLA puncture than for placebo puncture (P < 0.05).

CONCLUSION

In adults requiring repeated venous punctures, pain from cannulation may be evaluated at the first puncture with a Visual Analogue Scale, thus indicating or not the need for EMLA.