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Use of buffered lidocaine in bone marrow biopsies: a randomized, controlled trial.

PURPOSE/OBJECTIVES
To determine whether a difference exists in perceived pain during preprocedure anesthetic injection for bone marrow biopsy between buffered and unbuffered lidocaine, to determine whether pain levels change over time, and to investigate relationships between perceived pain scores and other variables.


DESIGN
A double-blind, randomized, experimental, crossover design.


SETTING
A large hospital in the midwestern region of the United States.


SAMPLE
48 patients undergoing bone marrow biopsy.


METHODS
The patients served as their own controls for the bilateral procedure. A 100 mm visual analog scale measured pain. A demographic questionnaire gathered the between-subjects exploratory variables.


MAIN RESEARCH VARIABLES
Perceived pain scores and type of lidocaine anesthetic solution (buffered versus unbuffered).


FINDINGS
Participants reported significantly lower pain scores on the side anesthetized with buffered lidocaine compared with the side anesthetized with unbuffered lidocaine. Higher pain scores were reported on the treatment side for participants who had received more than two surgical procedures. Patients who were members of a minority group had higher mean pain scores than Caucasians on the control side.


CONCLUSIONS
Buffered lidocaine is superior to unbuffered lidocaine as an anesthetic for bone marrow biopsy procedures.


IMPLICATIONS FOR NURSING
Advanced practice nurses perform a significant number of bone marrow biopsies and aim to improve patient comfort during invasive procedures. Use of unbuffered lidocaine should be questioned.