Succinylcholine

Succinylcholine-Induced Masseter Muscle Rigidity Successfully Managed With Propofol and Laryngeal Mask Airway: A Case Report and Brief Review

Masseter muscle rigidity following administration of succinylcholine for induction of general anesthesia is considered an early warning sign for the possibility of an episode of dreaded complication i.e., malignant hyperthermia. This report describes a case of masseter muscle rigidity encountered at the start of an emergency surgical procedure. After succinylcholine administration, laryngoscopy and intubation were not possible due to the masseter muscle spasms. This led to the use of laryngeal mask airway and propofol for the successful conclusion of the procedure with no intraoperative or postoperative complications. Later, the patient was discharged with instructions to avoid the contributing triggers in the future and recommendations of caffeine-muscle biopsy.

Intraocular pressure changes during rapid sequence induction and intubation: a comparison of rocuronium, atracurium, and succinylcholine

STUDY OBJECTIVE

To compare changes in intraocular pressure (IOP) during rapid sequence induction and intubation following rocuronium, succinylcholine, and atracurium.

DESIGN

Open-label, prospective, randomized study.

SETTING

Operating room at the Eye Foundation Hospital (University of Alabama at Birmingham)

PATIENTS

45 ASA physical status I, II, and III patients, aged 18 to 65 years, scheduled for elective eye surgery with general anesthesia.

INTERVENTIONS

Anesthesia was rapidly induced in unpremedicated patients with a fixed combination of midazolam 0.025 mg/kg, alfentanil 0.025 mg/kg, and propofol 1.5 mg/kg. Intubation was performed, as clinically indicated, approximately 60 seconds following administration of rocuronium 0.6 mg/kg, atracurium 0.5 mg/kg, or succinylcholine 1 to 1.5 mg/kg.

MEASUREMENTS AND MAIN RESULTS

Intraocular pressure was measured before induction of anesthesia (baseline), following anesthesia induction and administration of muscle relaxant (before intubation), and after intubation. The percent change in IOP from baseline was significantly decreased in the rocuronium group compared with the succinylcholine group (p = 0.046) before intubation. This trend continued after intubation, but the difference was no longer significant (p = 0.070). Intubation scores for rocuronium and succinylcholine groups were similar, and both scores were superior to that for the atracurium group (p = 0.002).

CONCLUSION

Intraocular pressure can be controlled during emergency induction of anesthesia and intubation with adequate depth of anesthesia and muscle relaxation. Rocuronium, succinylcholine, and atracurium all provided sufficient muscle relaxation to achieve successful intubation and no increase in IOP. However, rocuronium 0.6 mg/kg provided significantly better intubating conditions compared with atracurium, and it resulted in a significantly greater decrease in IOP compared with baseline than succinylcholine.

[Rapid sequence anesthetic induction via prehospital tracheal intubation]

The choice of sedation for emergency intubation remains controversial. This lack of consensus has led to various sedation protocols used in French prehospital care setting. A review of data from the literature suggests that the association etomidate-suxamethonium is probable the best choice for rapid sequence intubations in the prehospital setting. Its benefits include protection against myocardial and cerebral ischaemia, decreased risk of pulmonary aspiration, and a stable haemodynamic profile. Randomized studies are needed to substantiate the advantages of the association etomidate-suxamethonium for rapid sequences intubation in the prehospital setting.

Propofol reduces succinylcholine induced increase of masseter muscle tone

PURPOSE

Succinylcholine is known to increase the tone of the masseter muscles. As excessive jaw tension may complicate rapid sequence induction, we investigated three induction techniques, all including the use of succinylcholine, with respect to masseter muscle tone, neuromuscular blockade, intubation conditions, and time course of intubation.

METHODS

Sixty adult patients were allocated to one of three induction groups: Group THIO received 5 mg.kg-1 thiopentone, Group THIO/ATR received 5 mg.kg-1 thiopentone plus 0.05 mg.kg-1 atracurium for precurarization, and Group PROP received 2.5 mg.kg-1 propofol. All patients received 3 micrograms.kg-1 fentanyl and 1.5 mg.kg-1 succinylcholine. Time for induction of anaesthesia was recorded, and, after inserting a Grass Force Transducer between upper and lower incisors, jaw tone and the time course of jaw tension was recorded before and after the administration of succinylcholine.

RESULTS

No differences in the onset of sleep were observed among the three groups (Group THIO 33 +/- 2 sec: THIO/ATR 30 +/- 2 sec: PROP 35 +/- 2 sec, mean +/- SE). Masseter preloads following induction of anaesthesia were similar in all three groups (THIO 16.4 +/- 2.1 N: THIO/ATR 15.1 +/- 2.0 N: PROP 12.7 +/- 1.6 N). However, after administration of succinylcholine, the increase in masseter tone was less in Groups PROP (5.0 +/- 1.1 N) and THIO/ATR (6.4 +/- 2.1 N) than in Group THIO (12.4 +/- 3.0 N; P < 0.05).

CONCLUSION

Jaw tension after administration of succinylcholine is influenced by the choice of induction agent. The increase of masseter muscle tone is lower following propofol or thiopentone/atracurium induction than with thiopentone alone.

Onset of neuromuscular blockade and intubating conditions one minute after the administration of rocuronium in children

In a blinded randomized study intubating conditions were compared at one min following intravenous induction with propofol and either suxamethonium 1.0 mg.kg-1, or rocuronium 0.6 mg.kg-1. Onset time to maximal twitch depression, % block at one minute and clinical duration (time to 25% recovery) were measured. Sixty children undergoing elective tonsillectomy were recruited. Onset time [42s (SD 11s)] and clinical duration [3.3 min (SD 1.0 min)] in the suxamethonium group was significantly (P < 0.001) less than in the rocuronium group [92s (41s)] and [24.2 min (6.6 min)] respectively. The median twitch height at one minute for suxamethonium was 0% (range 0-8%) and significantly greater (P < 0.001) at 5% (range 0-22%) for rocuronium. Despite this there was no difference in the intubating conditions at one minute with 25 excellent/5 good in the suxamethonium group and 27 excellent/3 good in the rocuronium group. We conclude that rocuronium 0.6 mg.kg-1 gives optimal intubating conditions at one minute in children.

Serum potassium concentrations after suxamethonium in patients with familial amyloid polyneuropathy type I

BACKGROUND

Suxamethonium produces an abnormal increase in serum potassium in some neurological diseases and some authors have suggested that it is safer not to use this drug in patients with familial amyloid polyneuropathy (FAP). However, there are no data previously reported to support this hypothesis. The aim of this study was to evaluate the magnitude of the potassium increase produced by suxamethonium in FAP type I.

METHOD

Twenty-one FAP Met 30 patients anaesthetised for liver transplantation were studied. Age was 34.9 +/- 6.9 years (mean +/- SD), time elapsed from first symptom 5.5 +/- 3.2 years and weight was 14 +/- 9% below ideal body weight. Anaesthesia was induced with thiopentone and low-dose fentanyl. Samples for blood gas and 5 min after 1 mg/kg of suxamethonium was given for tracheal intubation.

RESULTS

Before induction serum potassium levels were 3.8 +/- 0.4 mmol/L. One minute after suxamethonium, values were 3.8 +/- 0.4 mmol/L and 5 min after 4.3 +/- 0.5 mmol/L. The maximal increase observed was 1.6 mmol/L (from 3.4 mmol/L to 5.0 mmol/L).

CONCLUSION

The average increase in plasma potassium concentrations observed in FAP patients after suxamethonium was similar to the increase observed in a normal population by others. Our study can exclude the hypothesis that an anomalous increase in potassium would be a typical and frequent response to suxamethonium in FAP met 30 patients. However, we cannot exclude that a dangerous rise in serum potassium may exist in a certain percentage of FAP patients.

The introduction of new drugs into anaesthetic practice: a perspective in pharmaceutical development and regulation

This article reviews the process by which new drugs are introduced into anaesthetic practice with particular emphasis on pharmaceutical development and government regulation. After a brief overview of the drug development process, new trends in drug development are discussed including implementation of pharmacokinetic, pharmacodynamic and toxicokinetic studies in both preclinical and human phases of drug evaluation. A synopsis of the drug regulatory process is provided and, in particular, the problem of unapproved drug use in anaesthesia is discussed. Ethical issues regarding physician-industry interactions are highlighted by examples of conflict of interest in anaesthesia. The processes of drug development and regulation require much effort and cooperation between clinicians, pharmaceutical manufacturers and government regulators to achieve a common goal; the development and utilization of safe and effective drugs. A fundamental understanding of these processes may further facilitate optimal drug utilization and the active involvement of anaesthetists in the drug development process.