Neuroleptic Malignant Syndrome: Complications, Outcomes, and Mortality.

Objective: Our study objective was to identify real-world rates of complications, mortality, and outcomes in patients with neuroleptic malignant syndrome (NMS) over the last decade in the United States.

Methods: A total of 1346 patients were obtained from the nationwide inpatient sample for the years 2002-2011. Common complications known to be associated with NMS were identified. Multivariable regression analyses were used to identify predictors of mortality.

Results: The most prevalent complication was rhabdomyolysis (30.1%). Other common complications were acute respiratory failure (16.1%), acute kidney injury (17.7%), sepsis (6.2%), and other systemic infections. Unadjusted mortality rate was 5.6%. Older age, acute respiratory failure, acute kidney injury, sepsis, and comorbid congestive heart failure were significant predictors of mortality. Acute respiratory failure was the strongest independent mortality predictor (p < 0.001).

Conclusion: In our large sample population-based study on NMS, we were able to identify the rates of several preselected complications and the mortality. The identification of independent mortality predictors in this study can guide physicians in the management and prognostication of this rare syndrome.