Comparing the Effect of Lidocaine-Prilocaine Cream and Infiltrative Lidocaine on Overall Pain Perception During Thoracentesis and Abdominocentesis: A Randomized Clinical Trial

Abstract

Background: Acute pain management is a core ethical commitment to medical practice. However, there is evidence to suggest that sometimes infiltrative lidocaine (IL) is not used prior to thoracentesis and abdominocentesis due to the belief that two needles cause greater pain than one. However, topical anesthetics like lidocaine-prilocaine cream (LPC) are painless, easy to use, and have less systemic side effects. Therefore, LPC can be a suitable substitute for medical procedures. Objectives: This study was designed to compare the analgesic effects of LPC with IL in thoracentesis and abdominocentesis. Methods: Patients were divided into two study groups, including individuals seeing a physician for a thoracentesis (N = 36) and those seeing a physician for an abdominocentesis (N = 33). Patients were randomly assigned to the IL (N = 35) or LPC (N = 34) groups for diagnostic and/or therapeutic purposes. The IL group received 100 mg of 2% lidocaine 5 minutes prior to their procedure, whereas the LPC group received 2.5 g of lidocaine-prilocaine cream. The cream was spread over a 20 - 25 cm2 area and occluded with dressing plaster for 30 minutes prior to the procedure. In both study groups, the thoracentesis and abdominocentesis were ultrasound-guided. Results: The findings suggest a non-significant difference between overall pain perception in LPC and IL groups generally, as well as specifically in abdominocentesis and thoracentesis groups. Furthermore, the result remained the same after controlling for confounding variables. The number of attempts to perform successful abdominocentesis was significantly higher in the LPC than IL (P-value = 0.003) group but was not significant in the thoracentesis group (P-value = 0.131). The level of patient satisfaction in the LPC and IL groups were not significantly different (P-value > 0.05). Conclusions: Overall, LPC appears to be an appropriate alternative to IL in reducing pain during thoracentesis and abdominocentesis, but it seemed to increase unsuccessful medical procedure attempts.