Comparison of phonomyography with balloon pressure mechanomyography to measure contractile force at the corrugator supercilii muscle

Abstract

P Pu ur rp po os se e: : Phonomyography is based on the creation of low frequency sounds during muscle contraction, which can be recorded and used for neuromuscular monitoring. In this study, balloon pressure mechanomyography, a novel method to measure the force of contraction via pressure changes in an air-filled balloon, was compared with phonomyography to determine neuromuscular blockade at the corrugator supercilii muscle. M Me et th ho od d: :After approval of the Ethics Committee and informed consent, 15 patients were studied. A small condenser microphone was taped to the area just above the eyebrow for phonomyography; an air-filled balloon was taped to the area just above the opposite eyebrow. After induction of anesthesia using remifentanil and propofol, a laryngeal mask airway was inserted without the aid of neuromuscular blocking agents. The facial nerve was stimulated supramaximally with single-twitch stimulation (0.1 Hz) using superficial electrodes placed on both temporal areas for onset and train-of-four stimulation every 12 sec during offset of neuromuscular blockade produced by mivacurium 0.1 mg·kg -1 . Onset and recovery measured by the two methods were compared using the t test and agreement between phonomyography and balloon pressure mechanomyography was examined using the Bland-Altman method.R Re es su ul lt ts s: : Onset, peak effect, and time to reach 25%, 75%, and 90% of control twitch response for phonomyography vs balloon pressure method were 83 ± 16 sec vs 81 ± 15 sec, 80 ± 15% vs 82 ± 17%, 7.7 ± 2.3 min vs 7.5 ± 2.4 min, 9.9 ± 4.1 min vs 10.5 ± 4 min, and 12.6 ± 4.3 min vs 13.1 ± 4.5 min respectively without being significantly different. Mean bias was 1% with limits of agreement of -9 and +9% of twitch height (T1).C Co on nc cl lu us si io on n: : We applied a balloon pressure method to measure the force at the corrugator supercilii. Phonomyography at the corrugator supercilii shows good agreement with this modified version of mechanomyography. Objectif

Prolonged (more than ten hours) neuromuscular blockade after cardiac surgery: report of two cases

“…The orbicularis oculi is more resistant to non-depolarizing agents than the adductor pollicis and direct facial muscle stimulation can occur unintentionally around the eye. 4 Alternative techniques, such as phonomyography, 15 have been proposed for monitoring NMB during cardiac surgery, …”

Brief review: Neuromuscular monitoring: an update for the clinician

“…It has been shown that the peak frequency of a typical signal is at 4-5 Hz and the maximum power occurs over a spectrum of frequencies up to 50 Hz. 42 Good to very good agreement with MMG or MMGlike methods has been shown for the adducting laryngeal muscles, 50 the CS, 21 and the AP. 51 In fact, at the CS, PMG was more sensitive in detecting the peak effect in comparison with AMG.…”

“…21 These methods measure the actual force by indirect methods, such as the change of pressure exerted onto a balloon compressed by movement of the thumb or contraction of the CS. Again, these methods are not easy to apply in the clinical setting, and are reserved primarily for research purposes as a gold standard or reference against which other methods can be tested.…”

Comparison of phonomyography, kinemyography and mechanomyography for neuromuscular monitoring

“…Initially, this method was called acoustic myography and used an air-chamber interface between the skin and the microphone. 7,8 It shows good agreement for several muscles with the gold standard of monitoring, MMG, [9][10][11] and can be applied at any muscle of interest.…”