Anesth Analg 2005;101:925-926
© 2005 International Anesthesia Research Society
LETTER TO THE EDITOR
Plasma Bupivacaine Concentrations Are Too Low to Explain Reduced Vecuronium Requirement with an Epidural
Prabhat K. Singh, MD,
Anil Agarwal, MD, and
Sanjay Dhiraaj, MD
Department of Anesthesia; Sanjay Gandhi Post Graduate Institute of Medical Sciences; Lucknow, India; aagarwal{at}sgpgi.ac.in
In Response:
We would like to thank Drs. Donati and Fortier for their interest in our article and their valuable comments. We agree that the marked reduction in the requirement of muscle relaxants that we observed with an epidural local anesthetic is in sharp contrast with the earlier reports (1–5). But do these observations really apply to our study? All the studies quoted by Drs. Donati and Fortier have observed the interaction of muscle relaxants and local anesthetics at the neuromuscular junction. However, the clinical practice of anesthesia is a polypharmacy; wherein the anesthetic state is the net result of the action of different drugs and their interactions. Propofol enhances both the presynaptic and postsynaptic effects of the vecuronium in the rat diaphragm (6). Marked reduction in the requirement of vecuronium in our study could have been the result of either additive or synergistic action of bupivacaine and propofol on the requirement of vecuronium (7).
References
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- Agarwal A, Pandey R, Dhiraaj S et al. Effect of epidural bupivacaine on induction and maintenance doses of propofol (evaluated by bispectral index) and maintenance doses of fentanyl and vecuronium. Anesth Analg 2004;99:1684–8.[Abstract/Free Full Text]
