UMEM Educational Pearls

Laryngospasm is defined as the cessation of ventilation despite persistent respiratory effort related to glottic closure.  Complications include hypoxia, bradycardia, and cardiac arrest.  In OR cases, one recent study found the laryngospasm to occur in 0.45/1000 cases.  In these children undergoing general anesthesia, risk factors included current upper respiratory infection, active asthma, airway anomalies, airway procedures, age < 3 months and the use of an LMA.  
Studies of the rates of laryngospasm in pediatric sedation have shown varied incidence, with prevalence between 0.43/1000 to 2.1/1000.  A metaanalysis showed that laryngospasm was more common with a combination of propofol and ketamine.
This study looked at moderate sedation cases where laryngospasm was not relieved with chin repositioning or the use of an airway adjunct.  Over a 7 year study period, 276,832 sedations were examined with 913 patients experiencing laryngospasm (3.3/1000 cases).  About 5% of these patients required intubation.  There were 2 cases of cardiac arrest, one with an underlying cardiac condition and one with a URI who was undergoing an echo.  Both of these patients had multiple agents used for sedation.
The isolated use of IV ketamine had a laryngospasm rate of 1.4/1000 cases.  The highest prevalence occured with propofol + ketamine (6.6/1000), propofol + midazolam + opiate (6.1/1000) and propofol + dexmedetomidine (5.8/1000).
The risk of laryngospasm was associated with a higher ASA status, younger age, presence of a URI, airway procedures, and certain propofol combination regimens.
Bottom line: While the prevalence of laryngospasm remains low during pediatric sedation, risk factors should be taken into consideration and the risk/benefits should be discussed in detail with the families.  Always be prepared for an airway emergency during sedation.

References

Cosgrove P, Krauss B, Cravero J and Fleegler E.  Predictors of Laryngospasm During 276,832 Episodes of Pediatric Procedural Sedation. Annals of Emergency Medicine 2022. epub ahead of print