Letters to the Editor: Letters & Announcements
We thank Dr. Dubois and colleagues for their comments.
The acceleromyography accuracy in postoperative awake patients may lead to significant clinical problems and the question is relevant (1). It is well documented that accuracy and variability of acceleromyography measurements depend on the current applied (2–3). We did not demonstrate that the monitoring TOF-Watch® acceleromyograph (Organon-Teknika, Puteaux, France) could not be used successfully in the recovery room. However, we stressed the importance to correctly apply acceleromyography in patients recovering from anesthesia. Our study was, in some respect, a blueprint of how not to apply accelerometry. Indeed, with a stronger current intensity (40 mA) and an attempt to obtain three constant consecutive measurements, Debaene et al.(4) had apparently no problem with obtaining stable train-of-four ratios.
How best can we assess whether postoperative awake patients have a significant degree of residual neuromuscular blockade? As stated by Dr. Dubois and colleagues and in agreement with the conclusion of our article: “The answers could be to monitor neuromuscular blockade mainly in the operating room in patients under anesthesia and to check the complete recovery from neuromuscular blockade before the emergence from anesthesia” (1).
Christophe Baillard, MD, PhD
Department of Anesthesiology & Intensive Care
1. Baillard C, Bourdiau S, Le Tourmelin P. et al. Assessing residual neuromuscular blockade using acceleromyography can be deceptive in postoperative awake patients. Anesth Analg 2004;98:854–7.
2. Kopman AF, Lawson D. Milliamperage requirements for supramaximal stimulation of the ulnar nerve with surface electrodes. Anesthesiology 1984;61:81–5.
3. Silverman DG, Connelly NR, O’Connor TZ, et al. Accelographic train-of-four at near-threshold currents Anesthesiology 1992;76:34–8.
4. Debaene B, Plaud B, Dilly MP, Donati F. Residual paralysis in the PACU after a single intubating dose of nondepolarizing muscle relaxant with an intermediate duration of action. Anesthesiology 2003;98:1042–8.