Acceleromyography of the orbicularis oculi muscle II: comparing the orbicularis oculi and adductor pollicis muscles
Article first published online: 3 OCT 2002
Acta Anaesthesiologica Scandinavica
Volume 46, Issue 9, pages 1131–1136, October 2002
How to Cite
Larsen, P. B., Gätke, M. R., Fredensborg, B. B., Berg, H., Engbæk, J. and Viby-Mogensen, J. (2002), Acceleromyography of the orbicularis oculi muscle II: comparing the orbicularis oculi and adductor pollicis muscles. Acta Anaesthesiologica Scandinavica, 46: 1131–1136. doi: 10.1034/j.1399-6576.2002.460912.x
- Issue published online: 3 OCT 2002
- Article first published online: 3 OCT 2002
- Received 5 July 2001,accepted for publication 1 May 2002
- adductor pollicis muscle;
- nerve stimulation;
- orbicularis oculi muscle
Background: The orbicularis oculi (OO) muscle has been recommended for neuromuscular monitoring when the adductor pollicis (AP) muscle is not available. We investigated whether neuromuscular block could be measured reliably from the orbital part of the OO muscle by the use of acceleromyography.
Methods: During propofol, fentanyl, and alfentanil anaesthesia two TOF-Guards® (Organon Teknika NV, Boxtel, the Netherlands) with acceleration transducers placed on the distal phalanx of the thumb and over the middle of the eyebrow, respectively, were used to measure neuromuscular block simultaneously in 23 patients during vecuronium-induced and neostigmine-antagonized neuromuscular block.
For both muscles, the simultaneously recorded first response (T1) in the train-of-four (TOF) and TOF-ratio were measured both during onset and recovery of the block. Furthermore, both the AP muscle T1 and TOF-ratio responses were plotted against 10% intervals of the OO muscle responses during onset and recovery, respectively.
Results: The orbicularis oculi muscle had a shorter latency and a faster recovery to TOF-ratio 0.80 compared with the AP muscle. During onset and recovery, pronounced variations of the AP muscle T1 and TOF-ratio responses were observed when compared with the OO muscle.
Conclusion: A significant clinical disagreement exists between the degree of paralysis measured at the OO and the AP muscles. It is impossible to obtain a reasonable estimate of the degree of block at the AP muscle when the block is measured from the OO muscle with acceleromyography. If used, there is substantial risk of overlooking a residual block, and adequate recovery of the block should be confirmed by a final AP muscle measurement.