Anesth Analg 2003;97:1545-1546
© 2003 International Anesthesia Research Society
LETTERS TO THE EDITOR
Omission of Muscle Relaxants Is Another Clinically Available Alternative in Fast-Track Cardiac Anesthesia
Samuel Metz, MD
Drexel University College of Medicine, Philadelphia, PA
To the Editor:
Concluding their article on fast-track cardiac anesthesia, Murphy et al. (1) list methods to reduce prolonged postoperative muscle blockade. Included were intermediate-acting muscle relaxants, blockade monitoring, routine examinations before extubation, and drug reversal.
The authors omitted another clinically available alternative: omission of muscle relaxants. The impression from our fast-track cardiac anesthesia program is that once intubation has been facilitated with succinylcholine, the operation requires no muscle relaxation.
Our ability to forego intraoperative muscle relaxants may reflect the collegial relations with our surgeons who appreciate our efforts to render their patients both extubatable and comfortable as rapidly as possible after operation.
I recommend this approach to reduce unwanted postoperative muscle blockade in this patient population.
Reference
- Murphy GS, Szokol JW, Marymont JH, et al. Recovery of neuromuscular function after cardiac surgery: pancuronium versus rocuronium. Anesth Analg 2003; 96: 1301–7.[Abstract/Free Full Text]
Response
Glenn S. Murphy, MD,
Joseph W. Szokol, MD, and
Jeffery S. Vender, MD
Department of Anesthesiology, Evanston Northwestern Healthcare, Northwestern University Feinberg School of Medicine, Evanston, IL
In Response:
We would like to thank Dr. Metz for his interesting comments about neuromuscular blocking drugs (NMBDs) in cardiac surgical patients. Most clinicians in the United States maintain neuromuscular blockade in this patient population using pancuronium, a long-acting agent (1). There are several potential indications for maintaining a moderate to deep level of neuromuscular blockade during cardiac surgery. Neuromuscular blocking drugs will reduce muscle rigidity associated with opioids, prevent shivering during hypothermia, limit oxygen consumption, and reduce muscle contractions during defibrillations (2). In addition, the possibility of patient or diaphragmatic movement during light stages of anesthesia can be reduced if paralysis is maintained (2).
Recent clinical trials have demonstrated that prolonged postoperative paralysis can occur following cardiopulmonary bypass, and that residual neuromuscular block can impair clinical recovery of the fast-track cardiac patient (3–5). Dr. Katz describes a technique that can used by clinicians to prevent residual postoperative paralysis: the avoidance of intraoperative muscle relaxants. The complications associated with residual neuromuscular block can be eliminated if intermediate- and long-acting NMBDs are not administered during the procedure. However, clinicians must be careful to maintain an adequate depth of anesthesia during all stages of the operation in order to reduce the possibility of patient movement. Our experience suggests that the risk of patient movement is greatest during separation from cardiopulmonary bypass, when light levels of anesthesia are frequently required due to hemodynamic instability. As Dr. Metz states in his letter, collegial relations with the surgeons are needed if muscle relaxants are avoided during cardiac surgery. In each patient, the risk of occasional patient movement must be balanced against the risks of prolonged residual neuromuscular block.
References
- Murphy GS, Szokol JW, Vender JS, et al. The use of neuromuscular blocking drugs in adult cardiac surgery: results of a national postal survey. Anesth Analg 2002; 95: 1534–9.[Abstract/Free Full Text]
- Hug CC. Anesthesia for adult cardiac surgery. In: Miller RD, ed. Anesthesia, 3rd ed. New York: Churchill Livingstone 1990: 1605–52.
- McEwin L, Merrick PM, Bevan DR. Residual neuromuscular block after cardiac surgery: pancuronium vs rocuronium. Can J Anaesth 1997; 44: 891–5.[Web of Science][Medline]
- Van Oldenbeek C, Knowles P, Harper NJN. Residual neuromuscular block caused by pancuronium after cardiac surgery. Br J Anaesth 1999; 83: 338–9.[Abstract/Free Full Text]
- Murphy GS, Szokol JW, Marymont JH, et al. Impact of shorter-acting neuromuscular blocking agents on fast-track recovery of the cardiac surgical patient. Anesthesiology 2002; 96: 600–6.[Web of Science][Medline]
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