Contrast of Buffered Vs. Unbuffered Lidocaine in Bone Marrow Biopsies

Oncology patients require numerous invasive procedures throughout their disease process including bone marrow biopsies (BMB). BMB.s are performed by a significant number of health care providers. One of the biggest concerns for health care providers is to improve patient comfort. The goal of this study was to reduce pain during BMBs.

Specific aims of the study were to determine if there is a difference in patients' perceived pain during injection of the pre-procedure anesthetic when buffered versus unbuffered lidocaine is administered to patient's receiving bone marrow biopsies.

A double blind, experimental crossover design was used to examine the difference in pain levels when using buffered versus unbuffered lidocaine prior to the bilateral bone marrow biopsy procedure. Based on a power analysis for a paired t-test, a convenience sample of 48 patients was enrolled into the study. Patients served as their own control. The site of first biopsy, and which lidocaine solution was administered first, were randomized. A 100mm visual analogue scale (VAS) was used to measure pain.

All data has been collected, are currently under analysis, and results will be completed in August 2006. Differences in groups will be examined using a paired t-test. A demographic questionnaire was used to gather select demographic variables. Correlative studies will be done to examine the relationship between the patient's perceived pain scores and several exploratory variables. Results of this study may change the current type of anesthetic used pre-BMBs thus improving patient comfort.