Postoperative Residual Curarization Research Articles

Atracurium is associated with postoperative residual curarization

Residual paralysis following the use of neuromuscular blocking drugs remains a clinical problem. As part of departmental quality assurance, we examined the degree of postoperative residual curarization (PORC) following atracurium. Forty patients undergoing general anaesthesia involving atracurium were studied. Quantitative neuromuscular monitoring (mechanomyography, Myograph 2000, Biometer, Denmark) was performed by assessing the response to supramaximal train-of-four (TOF) stimulation of the ulnar nerve. Anaesthesia was provided by non-participating clinicians who were blinded to the study data. A TOF ratio </=0.7 at extubation was classified as PORC. At antagonism of neuromuscular block, 70% (28/40) of patients had a TOF ratio </=0.7, and 65% (26/40) of patients had a TOF ratio </=0.7 at extubation. Peripheral nerve stimulator use was associated with a longer interval from antagonism of block to extubation (P=0.01), but was not associated with differences in atracurium dosage or a reduction in PORC at extubation. Patients with TOF ratio </=0.7 at extubation had surgery of shorter duration [59 (SEM 6) vs 103 (9) min, P<0.001], greater doses of atracurium relative to the duration of surgery [6 (1) vs 11 (1) micro g kg(-1) min(-1), P<0.005], and shorter intervals from administration of last dose of atracurium to antagonism of neuromuscular block [29 (2) vs 53 (9) min, P<0.005] and from antagonism to extubation [6 (1) vs 15 (4) min, P<0.01]. Duration of surgical procedure was the sole multivariate predictor of PORC [odds ratio 0.94 (95% confidence intervals 0.91-0.98), P<0.01]. PORC remains a clinical problem despite use of intermediate-duration neuromuscular blocking drugs and peripheral nerve stimulators. Patients undergoing procedures of short duration may be at risk of inappropriately early tracheal extubation, possibly due to work pressures. The association between suboptimal antagonism of neuromuscular blockade and short procedures needs reinforcement during postgraduate training and departmental quality assurance.

Atracurium is associated with postoperative residual curarization

Background. Residual paralysis following the use of neuromuscular blocking drugs remains a clinical problem. As part of departmental quality assurance, we examined the degree of postoperative residual curarization (PORC) following atracurium. Methods. Forty patients undergoing general anaesthesia involving atracurium were studied. Quantitative neuromuscular monitoring (mechanomyography, Myograph 2000, Biometer, Denmark) was performed by assessing the response to supramaximal train‐of‐four (TOF) stimulation of the ulnar nerve. Anaesthesia was provided by non‐participating clinicians who were blinded to the study data. A TOF ratio ≤0.7 at extubation was classified as PORC. Results. At antagonism of neuromuscular block, 70% (28/40) of patients had a TOF ratio ≤0.7, and 65% (26/40) of patients had a TOF ratio ≤0.7 at extubation. Peripheral nerve stimulator use was associated with a longer interval from antagonism of block to extubation (P=0.01), but was not associated with differences in atracurium dosage or a reduction in PORC at extubation. Patients with TOF ratio ≤0.7 at extubation had surgery of shorter duration [59 (sem 6) vs 103 (9) min, P<0.001], greater doses of atracurium relative to the duration of surgery [6 (1) vs 11 (1) µg kg–1 min–1, P<0.005], and shorter intervals from administration of last dose of atracurium to antagonism of neuromuscular block [29 (2) vs 53 (9) min, P<0.005] and from antagonism to extubation [6 (1) vs 15 (4) min, P<0.01]. Duration of surgical procedure was the sole multivariate predictor of PORC [odds ratio 0.94 (95% confidence intervals 0.91–0.98), P<0.01]. Conclusions. PORC remains a clinical problem despite use of intermediate‐duration neuromuscular blocking drugs and peripheral nerve stimulators. Patients undergoing procedures of short duration may be at risk of inappropriately early tracheal extubation, possibly due to work pressures. The association between suboptimal antagonism of neuromuscular blockade and short procedures needs reinforcement during postgraduate training and departmental quality assurance. Br J Anaesth 2002; 89: 766–9

Is postoperative residual curarization still a problem?

ORE THAN 20 years ago, it was docu. mented that postoperative residual curarization (PORC) was frequent in patients given longacting neuromuscular blocking agents. 1 Later studies from many different parts of the world confirmed these findings but also showed that the incidence was significantly less when intermediate-acting neuromuscular blocking agents were used. 2-5 This, together with more recent research documenting that residual block is a real threat to the patient, 6-1~ led to a gradual disappearance of longacting muscle relaxants from clinical use in many parts of the world and to a corresponding increase in the use of intermediate-acting drugs. Does this mean that the problems of PORC have disappeared? This article analyzes the present situation with respect to PORC after the use of muscle relaxants. Included are sections on the definition, the incidence, the diagnosis, the clinical significance, and the prevention of PORC.

Reversal agents for nondepolarizing neuromuscular blockade: Reasons for and development of a new concept

T HE INTRODUCTION of muscle relaxants into clinical anesthesia had an enormous impact on the possibilities of the surgical treatment of patients. The development of cleaner and shorteracting nondepolarizers with a benzylisoquinoline or a steroidal chemical structure further improved clinical anesthesia. However, their introduction coincided with a relatively high morbidity and mortality rate compared with anesthetic techniques when relaxants are not administered. 1 This is mainly caused by the occurrence of postoperative residual curarization, resulting in hypoxemia and airway obstruction. 2'3 Although the incidence of residual curarization with the newer intermediately short-acting and short-acting relaxants is lower than with the older long-acting relaxants, it still poses a problem. 4 The nondepolarizing relaxants still do not have a fast onset of action combined with a short duration of action. When a rapid onset is needed, a high dose is needed, causing a prolonged neuromuscular blockade, frequently outlasting the duration of surgery. Besides, a long duration of action may also cause a problem in the rare situation of intubate, cannot ventilate, which requires immediate restoration of spontaneous ventilation. In the clinical situation, an unexpected long duration of action of nondepolarizing relaxants may occur caused by an interaction with other drugs or by concurrent diseases present in the patient. With the current muscle relaxants, the possibility to reverse neuromuscular blockade thus remains important. For legal reasons, many anesthetists do routinely reverse neuromuscular blockade. 5 However, with the current reversal agents, this only provides an unjustified

Postoperative residual curarization with cisatracurium and rocuronium infusions

Postoperative residual curarization with cisatracurium and rocuronium infusions

Neuromuscular monitoring

This review summarizes recent reports on the techniques and the use of methods for monitoring neuromuscular function during anaesthesia. The latest news on the use of acceleromyography in the face and hand, on laryngeal and diaphragmal surface electromyography, on acoustic myography, on evaluation of intense neuromuscular block, and on postoperative residual curarization is presented and discussed. It is concluded that available evidence suggests that more attention should be paid by the anaesthetist to the problems of residual curarization and hence to proper monitoring of neuromuscular function using objective methods.

Room G, 10/17/2000 9: 00 AM - 11: 00 AM (PS) Intermediate Duration Neuromuscular Blocking Agents and Post-operative Residual Curarization

<b>Room G, 10/17/2000 9: 00 AM - 11: 00 AM (PS) Intermediate Duration Neuromuscular Blocking Agents and Post-operative Residual Curarization</b>

Residual curarization in the recovery room after vecuronium

We have investigated residual block after anaesthesia which included the use of the neuromuscular blocking agent vecuronium but no anticholinesterase, in 568 consecutive patients on admission to the recovery room. The ulnar nerve was stimulated submaximally using TOF stimulation (30 mA). Postoperative residual curarization was defined as a TOF ratio < 0.7. Of the 568 patients, 239 (42%) had a TOF < 0.7 in the recovery room. These patients had received a larger cumulative dose of vecuronium than patients who had full recovery (mean 7.7 (SD 3.6) mg vs 6.2 (2.7) mg; P < 0.05) and a shorter time had elapsed since the last vecuronium dose (117 (70) min vs 131 (80) min; P < 0.05). Of 435 patients whose trachea was extubated, 145 (33%) exhibited inadequate recovery from neuromuscular block. Six of these had one or no response to TOF stimulation and were reintubated. In the remaining 139 patients, neuromuscular block was successfully antagonized. Only 20 patients (3.5%) remembered TOF stimulation when questioned 2 h later in the recovery room, and discomfort associated with it was assessed using a visual analogue scale before discharge. We conclude that it is necessary to antagonize residual block produced by vecuronium.

Does Perioperative Monitoring of the Train-of-Four Response Influence the Frequency of Postoperative Residual Curarization in Propofol Anesthesia?

Background : Sometimes hypoxemia occurs in the postoperative recovery room because of post- operative residual curarization (PORC). Some reports show that postoperative residual curarization is common. FORC occurs after the use of the long-acting muscle relaxants. It has been recommended to use intermediate-acting muscle relaxants and a TOF monitor to decrease PORC. The purpose of this study was to examine whether the use of the TOF monitor during propofol anesthesia affects the incidence of postoperative residual curarization. Methods : 38 ASA I or II patients were divided randomly into two groups of 19 each. They received propofol-fentanyl-nitrous oxide for anesthesia. Pancuronium (80 ― 100 μg/kg) was used to facilitate tracheal intubation and additional doses were used to maintain surgical relaxation. The requirement for incremental doses of pancuronium and adequacy of recovery following reversal were assessed, either with (control group: n = 19) or without (experimental group: n = 19) TOF monitoring. Fifteen minutes after the arrival at the recovery room, neuromuscular function was assessed clinically and by using TOF. Results : There were no statistical differences in body weight, age, or duration of operation between the two groups. There was no statistical difference in the total dose of pancuronium and total dose of pancuronium relative to body weight and duration of operation. There were statistical differences in TOF ratio in the recovery room (0.73 vs. 0.86). The incidence of PORC was 47% in the control group and 5% in the experimental group. Conclusions : Though the monitoring of TOF did not effect the dose of muscle relaxant, it may have reduced the incidence of PORC. However, the PORC had no clinical significance because the mean TOF ratio in the two groups was over 0.7 and there were no clinical signs of residual muscle weakness. (Korean J Anesthesiol 2000; 38: 783-788)

Recovery from neuromuscular blockade: residual curarisation following atracurium or vecuronium by bolus dosing or infusions

We conducted a survey of the incidence of Postoperative Residual Curarisation (PORC) in two groups of patients following the use of atracurium or vecuronium. In the first group (B) the neuromuscular blocking drugs were administered by bolus dosing, and in the second group (I) by continuous fusion. On arrival in the recovery room, neuromuscular function was assessed both by compound evoked electromyogram (EMG) in a train of four pattern and also clinically, by the ability to sustain a headlift for > 5 seconds, and to cough. Results were obtained from 150 patients (100 in group B and 50 in group I). The incidence of PORC, as defined by a train of four ratio of < 0.7, on arrival in the recovery room was 12% in group B, and 24% in group I. Clinical criteria of adequate neuromuscular reversal revealed different results, with the majority of patients being unable to perform either clinical test on arrival in recovery. Those patients in whom a peripheral nerve stimulator was used intra-operatively did not have a reduced incidence of PORC. We have demonstrated that PORC is still a common occurrence even with intermediate duration of action neuromuscular blocking drugs.

Postoperative residual curarisation: incidence, aetiology and associated morbidity.

Postoperative residual curarisation: incidence, aetiology and associated morbidity.