Intraoperative acceleromyographic monitoring reduces the risk of residual neuromuscular blockade and adverse respiratory events in the postanesthesia care unit.
BACKGROUND
Incomplete recovery from neuromuscular blockade in the postanesthesia care unit (PACU) may contribute to adverse postoperative respiratory events. This study determined the incidence and degree of residual neuromuscular blockade in patients randomized to conventional qualitative train-of-four (TOF) monitoring or quantitative acceleromyographic monitoring. The incidence of adverse respiratory events in the PACU was also evaluated.


METHODS
One hundred eighty-five patients were randomized to intraoperative acceleromyographic monitoring (acceleromyography group) or qualitative TOF monitoring (TOF group). Anesthetic management was standardized. TOF patients were extubated when standard criteria were met and no fade was observed during TOF stimulation. Acceleromyography patients had a TOF ratio of greater than 0.80 as an additional extubation criterion. Upon arrival in the PACU, TOF ratios of both groups were measured with acceleromyography. Adverse respiratory events during transport to the PACU and during the first 30 min of PACU admission were also recorded.


RESULTS
A lower frequency of residual neuromuscular blockade in the PACU (TOF ratio < or = 0.9) was observed in the acceleromyography group (4.5%) compared with the conventional TOF group (30.0%; P < 0.0001). During transport to the PACU, fewer acceleromyography patients developed arterial oxygen saturation values, measured by pulse oximetry, of less than 90% (0%) or airway obstruction (0%) compared with TOF patients (21.1% and 11.1%, respectively; P < 0.002). The incidence, severity, and duration of hypoxemic events during the first 30 min of PACU admission were less in the acceleromyography group (all P < 0.0001).


CONCLUSIONS
Incomplete neuromuscular recovery can be minimized with acceleromyographic monitoring. The risk of adverse respiratory events during early recovery from anesthesia can be reduced by intraoperative acceleromyography use.
Murphy
Glenn S
GS
Department of Anesthesiology, Evanston Northwestern Healthcare, Northwestern University Feinberg School of Medicine, Evanston, Illinois 60201, USA. dgmurphy2@yahoo.com
Szokol
Joseph W
JW
Marymont
Jesse H
JH
Greenberg
Steven B
SB
Avram
Michael J
MJ
Vender
Jeffery S
JS
Nisman
Margarita
M
D000054:Acceleration; D000402:Airway Obstruction / Q000139:chemically induced / Q000175:diagnosis*; D000762:Anesthesia Recovery Period; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000139:chemically induced / Q000175:diagnosis* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods*; D008991:Monitoring, Physiologic / Q000379:methods; D009213:Myography / Q000295:instrumentation / Q000379:methods; D019148:Neuromuscular Blockade / Q000009:adverse effects*; D010092:Oximetry / Q000379:methods; D010100:Oxygen / Q000097:blood; D011182:Postoperative Care; D011183:Postoperative Complications / Q000517:prevention & control*; D012119:Respiration / Q000187:drug effects; D012307:Risk Factors; D012720:Severity of Illness Index
D010100:Oxygen