Prevalence of Malignant Hyperthermia Diagnosis in New York State Ambulatory Surgery Center Discharge Records 2002 to 2011.

BACKGROUND

Malignant hyperthermia (MH) is a rare yet potentially fatal pharmacogenetic disorder triggered by exposure to inhaled anesthetics and the depolarizing neuromuscular blocking drug succinylcholine. Epidemiologic research on MH is largely limited to inpatients. In this study, we examined the prevalence of recorded MH diagnosis in patients discharged from ambulatory surgery centers (ASCs).

METHODS

We analyzed the New York State Ambulatory Surgery Dataset for the years 2002 to 2011 and identified patients with a discharge diagnosis of MH due to anesthesia by using the International Classification of Disease, Ninth Revision, Clinical Modification code 995.86. MH prevalence was assessed by demographic, clinical, and ASC characteristics.

RESULTS

During the study period, 31 of 17,092,765 discharges from ASCs had a recorded diagnosis of MH, yielding a prevalence of 0.18 per 100,000 discharges (95% confidence interval, 0.12-0.25). The prevalence of recorded MH diagnosis per discharge differed significantly across age groups and surgical procedure categories. All patients with a recorded diagnosis of MH were from hospital-based ASCs and were discharged alive from ASCs.

CONCLUSIONS

The prevalence of recorded MH diagnosis in ASC patients is approximately 1 per 500,000 and varies considerably with surgical procedures.