Related Experiment Videos
Forces applied during laryngoscopy in children. Are volatile anaesthetics essential for suxamethonium induced muscle
M J Bucx1, R T Van Geel, A E Meursing
1Department of Anaesthesia, Erasmus University, Rotterdam, The Netherlands.
Insights
Suxamethonium increases upper airway muscle tone in children, even without volatile anesthetics. This heightened muscle rigidity did not impact laryngoscopy or intubation.
Area of Science:
- Anesthesiology
- Pediatric Anesthesia
- Pharmacology
Background:
- Suxamethonium is known to increase masticatory muscle tone in children when used with volatile anesthetics.
- The necessity of volatile anesthetics for this effect remains unclear.
Purpose of the Study:
- To investigate whether suxamethonium increases upper airway muscle tone in children independently of volatile anesthetics.
- To quantify upper airway muscle tone using forces applied during laryngoscopy.
Main Methods:
- 54 children (aged 2-15 years) were anesthetized using propofol, fentanyl, and nitrous oxide, avoiding volatile agents.
- Muscle relaxation was induced with either suxamethonium (n=26) or vecuronium (n=28).
- Forces during laryngoscopy were measured to assess upper airway muscle tone.
Main Results:
- Significantly greater forces were applied during laryngoscopy in the suxamethonium group compared to the vecuronium group (25 N vs. 21 N maximal; 16 N vs. 13 N mean).
- These findings indicate increased upper airway muscle tone following suxamethonium administration, irrespective of volatile anesthetics.
- Increased muscle tone did not negatively affect laryngoscopy difficulty or intubation conditions.
Conclusions:
- Suxamethonium administration leads to increased upper airway muscle tone in pediatric patients, independent of volatile anesthetics.
- The unique characteristics of the masseter muscle may contribute to suxamethonium-induced rigidity.
- This effect does not appear to complicate airway management procedures like laryngoscopy and intubation.
Abstract:
Increased masticatory muscle tone after administration of suxamethonium has been demonstrated in children when combined with volatile anaesthetics. Whether volatiles are a prerequisite for this phenomenon is not known. In this study upper airway muscle tone, including the tone of the masticatory muscles, was determined in 54 children (age range 2-15 years), anaesthetized with propofol, fentanyl and nitrous oxide and avoiding any use of volatiles. The children were either relaxed with suxamethonium (n = 26) or vecuronium (n = 28). The forces applied during laryngoscopy were used to quantify upper airway muscle tone and were significantly greater in the suxamethonium group than in the vecuronium group: maximally applied force was 25 N versus 21 N (P = 0.008), and mean applied force was 16 N versus 13 N (P = 0.006), respectively. The results of this study indicate that upper airway muscle tone increases after administration of suxamethonium in children independent of the presence of volatile anaesthetics. Moreover, increased muscle tone had no effect on the difficulty of laryngoscopy or the intubation conditions. Increased masseter muscle rigidity after suxamethonium could be due to the very unique characteristics of this muscle.