Search

Residual neuromuscular block is common after the use of neuromuscular blocking drugs during anesthesia. Although careful reversal [table: see text] techniques usually result in adequate return of neuromuscular recovery, sometimes it is not possible to achieve full recovery of neuromuscular block. Ventilatory support and maintenance of a patent airway are required until recovery can be demonstrated. In those situations, in which some TOF fade is still obvious, the anesthesiologist should consider retaining the endotracheal tube in position; it is not a sign of failure to return a patient whose trachea is still intubated to the postanesthesia care unit. The inadvertent extubation of patients who are partially paralyzed results in increased postoperative morbidity.

Background: The linearity of cisatracurium elimination and its concentration-effect relation were determined as part of a traditional rich data study with three dose levels in patients receiving balanced anesthesia., Methods: Forty-eight adults with American Society of Anesthesiologists status I-II were randomized to receive an intravenous bolus dose of 0.075, 0.15, or 0.30 mg/kg cisatracurium. Anesthesia was induced and maintained with nitrous oxide-oxygen, propofol, and fentanyl. The mechanical response of the adductor pollicis muscle was recorded. Arterial blood samples were collected over 8 h. Cisatracurium, laudanosine, and the monoquaternary alcohol concentrations were measured by high-performance liquid chromatography. To assess the relative contribution of the input function, a parametric (assuming elimination from both the central and peripheral compartments) and a nonparametric pharmacokinetic-pharmacodynamic model were both applied to data., Results: Dose proportionality of the body disposition of cisatracurium and its two major metabolites at doses up to 0.30 mg/kg was confirmed. With the parametric approach, the effect compartment concentration at 50% block (EC50) significantly increased with the dose (136 vs. 157 vs. 209 ng/ml), whereas the effect compartment equilibration rate constant decreased (0.0675 vs. 0.0568 vs. 0.0478 min(-1)). A similar dose-dependent effect of the pharmacokinetic-pharmacodynamic relation was observed with the nonparametric approach, but the trend was 50% less pronounced., Conclusion: A dose-related change in pharmacokinetic-pharmacodynamic parameters was identified with both modeling approaches. A pharmacokinetic origin was ruled out, although no definite explanation of the underlying mechanism could be provided. These findings suggest that doses relevant to the anesthetic practice be used for estimation of EC50.

The purpose of this paper is to describe the impact of anaesthesia research on clinical practice. The evolution of neuromuscular blocking drugs from the laboratory to the operating room is used as an example. Particular emphasis is given to the pioneers whose vision made this possible: H. R. Griffith and G. E. Johnson; D. Savage, J. B. Stenlake and W. C. Bowman and J. Viby-Mogensen. Our challenge is to ensure the supply of clinical scientists for the future.

The synergistic effect of pancuronium bromide (PCB) and d-tubocurarine (DTC) on the onset time of neuromuscular blockade was tested in 108 ASA physical status I and II adults anaesthetized with thiopentone, nitrous oxide and halothane. Either saline or a small (priming) dose (DTC, 0.04 mg X kg-1, or PCB, 0.007 mg X kg-1) was administered 3 min before a paralyzing dose of either DTC or PCB. The total dose of relaxant was equivalent to DTC, 0.4 mg X kg-1, or PCB, 0.07 mg X kg-1. Neuromuscular activity was measured using train-of-four stimulation applied every 12 s. Time to 50 per cent first twitch blockade was 63 +/- 4.6 s (mean +/- SEM) with DTC and 88 +/- 5.2 s with PCB (p less than 0.002). Times to 90 per cent blockade were not different between the two drugs (161 +/- 20 s and 141 +/- 21 s respectively). Priming a DTC blockade with either DTC or PCB or priming a PCB blockade with PCB produced an acceleration of less than 10 s at all levels of blockade. Compared with PCB alone, priming PCB blockade with DTC reduced the time to 50 per cent blockade to 71 +/- 4.5 s (p less than 0.02) and to 90 per cent blockade to 111 +/- 8 s (p less than 0.05). Priming did not affect the duration of action significantly, except in the case of PCB priming of DTC, where duration was increased from 39 +/- 4.4 to 57 +/- 4 min (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

A 69 year old man receiving echothiophate eye drops for glaucoma was given a controlled infusion of succinylcholine during elective surgery for incisional hernia. Neuromuscular blockade was assessed by the measurement of the force of contraction of the adductor pollicis muscle. Only 9.5 mg succinylcholine were required for tracheal intubation and 1.1 mg/min for maintenance. When the infusion was stopped, recovery of neuromuscular transmission was rapid and uneventful. Plasma cholinesterase activity was 62 per cent below normal, but the enzyme was qualitatively normal. Thus, muscle relaxation can be achieved safely with a succinylcholine infusion in patients with decreased plasma cholinesterase activity if neuromuscular function is closely monitored.

Copyright of Canadian Journal of Anaesthesia / Journal Canadien d'Anesthésie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Anaesthesia / Journal Canadien d'Anesthésie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Anaesthesia / Journal Canadien d'Anesthésie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)