Never use neuromuscular blocking agents for sedation.

We read with appreciation and concern the review article by Isenstein et al,’ which appeared in the October 1992 issue of Chest. The authors have provided clinically relevant information that is familiar to most anesthesiologists, but it may not be the case for other specialists. With more newly available drugs and better monitoring techniques, there is a current trend toward increasing usage of neuromuscular blocking agents (NMBAs) in the ICU. Unless they are applied appropriately for specific indications, however, the resurgence of the use of these agents may not be a welcome sign. As mentioned in the Isenstein article, in addition to failure ofcoughing during tracheal suctioning and prolonged paralysis, there may also have been direct damage to the neuromuscular junction.’ Prolonged use of NMBAs may be associated with prolonged neuromuscular dysfunction with neurogenic or myopathic abnormalities as shown on electrodiagnostic studies and muscle biopsies. Recovery of strength may take months, and weaning from a mechanical ventilatorcan become difficult. The risks of nosocomial infection and disuse atrophy are increased as well. Gooch et al suggested that the blockade of neuromuscular transmission might sometimes be severe enough to lead to actual denervation of some muscle fibers. Nevertheless, our major concern is what we believe to be an inadvertent mistake made by the authors. We strongly feel that the subject title Sedation under the section of Indication is inappropriate, misleading, and needs to be corrected. It should be replaced with something like “Paralysis for Diagnostic and Therapeutic Procedures.” it is well known to anesthesiologists as well as intensivists, but not to other physicians, that NMBAS not only do not reduce anesthetic requirement but also do not cause sedation or amnesia at all.t45 It is paralysis not sedation that NMBAs can provide. This point cannot be overemphasized or a disaster may occur, particularly if mechanical ventilation is not instituted. Adequate medications for amnesia and sedation should always be provided concomitantly. Without them, tremendous stress reaction under that situation can be extremely harmful to certain patients. A syndrome of traumatic neurosis can also be induced by awakened paralysis due to NMBAs.2’ For those who are not acquainted with NMBAs, nothing is more dangerous than using them for sedation.