Monitoring neuromuscular block: an update

Abstract

SummaryThe first part of this article presents an update of the basic considerations of neuromuscular monitoring. It emphasises the need to assure supramaximal stimulation, to place the stimulating electrodes correctly and to use appropriate sites for nerve stimulation as well as appropriate stimulation patterns. The second part focuses on current developments and ongoing discussion. The authors describe the performance of acceleromyography and the need for initial calibration when using these quantitative devices.

Residual Neuromuscular Blockade in Critical Care

“…25 The twitch response is decreased 2% to 10% per degree Celsius reduction in the muscle temperature. In patients given NMBAs, pharmacokinetic changes occur because of the effects of hypothermia on drug disposition.…”

“…Another concern is the lack of consensus about the TOF ratio needed to exclude clinically important RNMB. 23,25 TOF is an assessment that involves stimulation of peripheral nerves. A series of 4 light shocks are applied to a peripheral nerve, and visual observation of the muscular response to each shock is used to measure the degree of neuromuscular blockade.…”

Closed-loop Administration of General Anaesthesia: From Sensor to Medical Device

“…Monitoring myorelaxation has long been shown to be a factor of quality of anaesthesia as it enables adequate titration during surgery and security when weaning ventilation and extubating patients [16][17][18]. Myolexation monitoring relies on electrical stimulations of the ulnar nerve at the wrist or of the palpebral orbicular muscle: results are expressed as a percentage of muscular response, with known thresholds (targets) for surgery and extubation [19]. In current practice, various types of electrical stimulations can be used.…”

Universal neuromuscular blockade monitoring – a reply

“…In contrast, techniques using acceleromyography are suitable for clinical practice. Issues around calibration, drift and 'normalisation' have been debated [3], but a systematic review concluded that '(acceleromyography) improves detection of postoperative residual paralysis and that recovery of TOF ratio to unity indicates, with a high predictive value, recovery of pulmonary and upper airway function from residual neuromuscular blockade' [4]. Movement of the stimulated limb will affect calibration of the device for twitch height measurement.…”