A1496
October 21, 2009
9:00 AM - 11:00 AM
Room Area C An Evaluation of Nerve Block Duration and Patient Satisfaction ** Martin Harrell, M.D., Monika Nanda, M.D., M.P.H., Haley Meyer, B.S., Karamarie Fecho, Ph.D.
Anesthesiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina Introduction : Quality and safety in medicine are issues of great importance in today's healthcare system. 1 Anesthesiologists, among other healthcare providers, are being pressured to track their practices and outcomes and improve perceived weaknesses. 2 The aim of this study was to determine the effectiveness of nerve blocks, in terms of patient satisfaction, complications, and the duration of pain control, numbness and loss of strength. We further aimed to explore factors that might be associated with increased block duration.
Method : After receiving approval from the Institutional Review Board, prospective data were obtained from patients undergoing peripheral nerve blocks. Data related to the block itself included the type of block, time of block onset, drugs administered, whether epinephrine and clonidine were administered, and whether ultrasound and/or nerve stimulation were used. A follow-up telephone questionnaire for outpatients and a follow-up bedside visit questionnaire for inpatients were used to collect additional information within 24-48 hours after the block. The questionnaire included questions on time to pain onset, return of strength, return of sensation, and complications (i.e., bruising, drowsiness, soreness, and swelling). Patient satisfaction was recorded using a 10 point scale (0=completely dissatisfied; 10=completely satisfied). Data were analyzed using descriptive statistics and Analysis of Variance.
Results: The follow-up response rate was 63.8%. Data were gathered from 118 subjects. Nerve blocks were performed using ultrasound with (41.3%) or without (39.1%) nerve stimulation, nerve stimulation alone (19.6%). The blocks included brachial plexus (34.5%), femoral (19.0%), sciatic (23.2%), trunk blocks (11.3%) and other peripheral extremity blocks (10.1%). Local anesthetics were ropivacaine (52.4%), bupivacaine (29.8%), mepivacaine (7.7%) and lidocaine (5.4%). Epinephrine was used in 49.4% and clonidine in 26.8% of local anesthetic mixtures. The mean±SD time to pain onset was 15.1±9.8 hours. Strength returned in 16.7±10.7 hours and numbness was gone after 17.1±11.4 hours. Block duration was not influenced by epinephrine, clonidine or the use of ultrasound or nerve stimulation (alone or in combination). Complications occurred in 12 (10.2%) blocks, with bruising being most common. The mean±SD patient satisfaction score was 8.8±2.3 and only 10 (8.5%) subjects reported a patient satisfaction score ≤5. One hundred two (86.4%) subjects reported that they would have a future nerve block.
Conclusions: These results show that the duration of nerve block, in terms of pain control, strength and numbness, is generally over 12 hours, although significant variability exists and factors that might account for that variability were not identified. Complications were minor and occurred in 10% of all blocks. Patients were generally very satisfied with their experience, suggesting a high quality of care.
References:
1 Committee on Quality of Health Care in America, Institute of Medicine. Kohn LT, Corrigan JM, Donaldson MS, Eds. To err is human: Building a safer health system. Washington, D.C.: National Academies Press, 1999.
2 Woolf SH. Patient safety is not enough: Targeting quality improvements to optimize the health of a population. Ann Intern Med 240:33-36, 2004.
From Proceedings of the 2009 Annual Meeting of the American Society Anesthesiologists.