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Risk evaluation for needle‐nerve contact related to electrical nerve stimulation in a porcine model
Author(s) -
Vassiliou T.,
Müller H.H.,
Limberg S.,
De Andres J.,
Steinfeldt T.,
Wiesmann T.
Publication year - 2016
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/aas.12664
Subject(s) - medicine , stimulation , peripheral nerve , confidence interval , peripheral , anatomy , anesthesia
Background For performing peripheral nerve blocks, the risk for needle‐nerve contact ( NNC ) as an adverse event for low and high current thresholds has not yet been clearly defined when nerve stimulator guided techniques were applied. This experimental study aimed to investigate the risk of NNC s when applying stimulation currents between 0.1 and 2 mA (in increments of 0.1 mA). Methods Brachial plexus nerves were exposed surgically in five anesthetized pigs. An insulated needle connected to a nerve stimulator was placed at 10 mm distance to the targeted nerves. Current intensity was adjusted according to randomization (0.1–2.0 mA, increments of 0.1 mA). The needle tip was advanced toward the nerve until a motor response was elicited. The frequencies of NNC s for each of the adjusted current intensities were noted. Risks of NNC s were calculated according to the analysis of 95% confidence intervals (95% CI ). Results We executed 2000 needle placements with stimulation currents ranging from 0.1 to 2.0 mA. The risks for NNC at low current intensities were 0.85 (95% CI , 0.77–0.91) for 0.3 mA and 0.5 (95% CI , 0.4–0.6) for 0.5 mA, respectively. For high current intensities, risks of 0.13 (95% CI , 0.07–0.21) for 0.9 mA and 0.01 (95% CI , 0–0.05) for 1.1 mA were calculated. Conclusions In this experimental animal study, a relevant reduction in the risk of NNC s could be observed when high current intensities (0.9–1.1 mA) were applied compared to low current intensities (0.3–0.5 mA).