Arm-to-arm variation when evaluating neuromuscular block: an analysis of the precision and the bias and agreement between arms when using mechanomyography or acceleromyography

TY - JOUR

T1 - Arm-to-arm variation when evaluating neuromuscular block: an analysis of the precision and the bias and agreement between arms when using mechanomyography or acceleromyography

AU - Claudius, C

AU - Skovgaard, L T

AU - Viby-Mogensen, J

PY - 2010/9

Y1 - 2010/9

N2 - BackgroundStudies comparing acceleromyography and mechanomyography indicate that the two methods cannot be used interchangeably. However, it is uncertain to what extent differences in precision between the methods and the naturally occurring arm-to-arm variation have influenced the results of these studies. Accordingly, the purpose of this study was to examine the precision and the arm-to-arm variation, when the same method is used on both of the arms. MethodsIn the first part (n=20), mechanomyography was applied bilaterally and in the second part acceleromyography (n=20). Anaesthesia was induced with propofol and opioid, and neuromuscular block with rocuronium 0.6 mg kg-1. The precision of the two methods and the bias and limits of agreement between the arms were evaluated using train-of-four (TOF) stimulation, without and with referral to the initial baseline value, that is, normalization. ResultsBoth methods were found to be precise (<5 variation) without any difference between the dominant and non-dominant arms. There were no significant biases between the arms, except for the onset time obtained with acceleromyography, which was 10 longer for the dominant arm. However, the individual differences (limits of agreement) were wide (0.20-0.25 at TOF 0.90). Normalization during recovery did not change bias or limits of agreement between the arms. ConclusionsIn the research setting, acceleromyography and mechanomyography are both precise methods without difference between the arms. Although there is no mean bias between the arms, both methods show wide individual differences (limits of agreement), which might to a large extend explain the differences often found when two different methods are compared on the contralateral arms.

AB - BackgroundStudies comparing acceleromyography and mechanomyography indicate that the two methods cannot be used interchangeably. However, it is uncertain to what extent differences in precision between the methods and the naturally occurring arm-to-arm variation have influenced the results of these studies. Accordingly, the purpose of this study was to examine the precision and the arm-to-arm variation, when the same method is used on both of the arms. MethodsIn the first part (n=20), mechanomyography was applied bilaterally and in the second part acceleromyography (n=20). Anaesthesia was induced with propofol and opioid, and neuromuscular block with rocuronium 0.6 mg kg-1. The precision of the two methods and the bias and limits of agreement between the arms were evaluated using train-of-four (TOF) stimulation, without and with referral to the initial baseline value, that is, normalization. ResultsBoth methods were found to be precise (<5 variation) without any difference between the dominant and non-dominant arms. There were no significant biases between the arms, except for the onset time obtained with acceleromyography, which was 10 longer for the dominant arm. However, the individual differences (limits of agreement) were wide (0.20-0.25 at TOF 0.90). Normalization during recovery did not change bias or limits of agreement between the arms. ConclusionsIn the research setting, acceleromyography and mechanomyography are both precise methods without difference between the arms. Although there is no mean bias between the arms, both methods show wide individual differences (limits of agreement), which might to a large extend explain the differences often found when two different methods are compared on the contralateral arms.

KW - Acceleration

KW - Adolescent

KW - Adult

KW - Aged

KW - Androstanols

KW - Anesthesia Recovery Period

KW - Bias (Epidemiology)

KW - Electric Stimulation

KW - Female

KW - Humans

KW - Middle Aged

KW - Monitoring, Intraoperative

KW - Myography

KW - Neuromuscular Blockade

KW - Neuromuscular Junction

KW - Neuromuscular Nondepolarizing Agents

KW - Reproducibility of Results

KW - Young Adult

U2 - 10.1093/bja/aeq162

DO - 10.1093/bja/aeq162

M3 - Journal article

C2 - 20595196

SN - 0007-0912

VL - 105

SP - 310

EP - 317

JO - British Journal of Anaesthesia

JF - British Journal of Anaesthesia

IS - 3

ER -