Comparison of T1–T4 decrement between upper and lower extremity muscles can indicate differences between recovery time from neuromuscular blockade, which may have repercussions for neurophysiologic intraoperative monitoring. We investigated decrement between T1 and T4 hand and foot muscle responses on quantitative train-of-four (TOF) test.
Study analyzed differences between recovery of foot, abductor hallucis muscle, and hand, first dorsal interosseous muscle, by application of quantitative TOF test on 147 patients undergoing lumbar spine surgery. T1 to T4 decrements on hand and foot TOF were obtained and classified into different groups, depending on elapsed time after administration of neuromuscular blocking agents and its dose.
There are significant differences between T1–T4 decrements obtained on hand and foot (P < 0.05). T1–T4 decrement determined on abductor hallucis muscle was lower indicating more rapid recovery than the first dorsal interosseous muscle (P < 0.05). Interestingly, quite opposite, more pronounced decrement in foot TOF than hand was showed in 4% (5 out of all 147 cases).
The observed difference between recovery of hand and foot muscles suggests that quantitative TOF test should be performed on extremities for which accurate data about the level of neuromuscular blockade is sought. During lumbar spine surgery monitoring, in addition to hand TOF, foot TOF should be included.
*Department of Clinical Neurophysiology, NYU Langone Medical Center, New York, New York, U.S.A.; and
†Division of Clinical Neurophysiology, Department of Neurology, NYU School of Medicine, New York, New York, U.S.A.
Address correspondence and reprint requests to Aleksandar Beric, MD, DSc, Division of Clinical Neurophysiology, NYU Hospital for Joint Diseases, 301 East 17th Street, Suite 1534, New York, NY 10003, U.S.A.; e-mail: firstname.lastname@example.org.