Decreased mivacurium infusion rate and delayed neuromuscular recovery after metoclopramide: a randomized double blind placebo-controlled study:

[General anesthesia for ambulatory surgery : Clinical pharmacological considerations on the practical approach]

Due to modern surgical and anesthesia techniques, many patients undergoing small or even medium surgical procedures will recover within minutes and can then be discharged after a few hours of monitoring. Aside from an optimized surgical technique, a precise and differentiated anesthesia concept is needed to guarantee rapid recovery and home readiness. Nowadays, remifentanil-propofol represents the standard regime in ambulatory anesthesia. The use of alfentanil, desfluran or sevofluran is also possible whereas other intravenous or inhaled anesthetics or other opioids are rarely used. If endotracheal intubation is necessary, a reduced intubating dose of neuromuscular blockers (NMB), such as mivacurium, atracurium and rocuronium, i.e. 1-1.5-times the 95 % effective dose (ED95) is a good possibility to accelerate neuromuscular recovery while still having acceptable intubation conditions. Due to its limitations and contraindications, succinylcholine is not the first choice but may be used in non-fasting patients in need of urgent (ambulatory) surgery, e.g. in bleeding women undergoing dilation and curettage. Even with these reduced dosages monitoring of neuromuscular recovery is crucial and should be applied to all patients when NMBs are used. Furthermore, patients should receive a risk-adapted postoperative nausea and vomiting (PONV) prophylaxis, e.g. with 4 mg dexamethasone and 4 mg ondansetron. Postdischarge nausea and vomiting (PDNV) should be anticipated by a new risk score and prophylaxis or treatment should be initiated. For postoperative pain relief, local or regional anesthesia techniques, such as infiltration, field or nerve blocks should be applied where possible. In addition, non-opioid analgesics are the basic treatment while longer-lasting opioids are only necessary for some patients.

Do metoclopramide and ondansetrone alter mivacurium-induced neuromuscular blockade? - a randomised trial

BACKGROUND

We aimed to investigate the effects of metoclopramide and ondansetrone on mivacurium neuromuscular blockade.

METHODS

Seventy five, ASA I-II patients, aged 18-65 and scheduled for elective surgery requiring tracheal intubation were included in the study. The patients received metoclopramide 10 mg, ondansetrone 4 mg or normal saline 5 mL; group M, group O, group NS (n=25), respectively. Before anesthesia study drugs were administered in a volume of 5 mL. The level of plasma cholinesterase were obtained before and 5 minutes after the administration of study drugs and 5 minutes after the administration of mivacurium. Onset time, T25, T75, T25-75, T90 levels were compared with each other and differences between each patients were investigated. After recording T90, the study was terminated and surgery was started.

RESULTS

Onset time was significantly shorter in group M, than the other two groups. Onset time in group O was significantly shorter than in group NS. In Group M T25, T75, T90 and recovery indices were significantly greater than in Group NS (p<0.001). In Group O T25, T75 were greater than Group NS (p<0.01 and p<0.05, respectively). In Group M T75, T90 and emergence indices were significantly higher than Group O (p<0.001, p<0.01, p<0.001, respectively). In Groups M and O, plasma cholinesterase levels decreased significantly (p<0.001) after administration of study drugs and mivacurium. Plasma cholinesterase also was reduced in Group NS 5 minutes after the administration of mivacurium (p<0.001).

CONCLUSION

Ondansetrone is believed to be more reliable agent than metoclopramide when used with mivacurium.