Intravenous dantrolene in hypermetabolic syndromes: a survey of the U.S. Veterans Health Administration database.

Background: Intravenous dantrolene is often prescribed for hypermetabolic syndromes other than the approved indication of malignant hyperthermia (MH). To clarify the extent of and indications for dantrolene use in conditions other than MH, we sought to document current practices in the frequency, diagnoses, clinical characteristics and outcomes associated with dantrolene treatment in critical care settings.

Methods: Inpatients receiving intravenous dantrolene from October 1, 2004 to September 30, 2014 were identified retrospectively in the U.

Updated variant curation expert panel criteria and pathogenicity classifications for 251 variants for RYR1-related malignant hyperthermia susceptibility.

The ClinGen malignant hyperthermia susceptibility (MHS) variant curation expert panel specified the American College of Medical Genetics and Genomics/Association of Molecular Pathologists (ACMG/AMP) criteria for RYR1-related MHS and a pilot analysis of 84 variants was published. We have now classified an additional 251 variants for RYR1-related MHS according to current ClinGen standards and updated the criteria where necessary. Criterion PS4 was modified such that individuals with multiple RYR1 variants classified as pathogenic (P), likely pathogenic (LP), or variant of uncertain significance (VUS) were not considered as providing evidence for pathogenicity.

Drug-induced Hyperthermic Syndromes in Psychiatry.

Hyperthermia, or extreme elevations in body temperature, can be life-threatening and may be caused by prescription drugs or illegal substances acting at a number of different levels of the neuraxis. Several psychotropic drug classes and combinations have been associated with a classic clinical syndrome of hyperthermia, skeletal muscle hyper-metabolism, rigidity or rhabdomyolysis, autonomic dysfunction and altered mental status ranging from catatonic stupor to coma. It is critical for clinicians to have a high index of suspicion for these relatively uncommon drug-induced adverse effects and to become familiar with their management to prevent serious morbidity and mortality.

Genomic Screening for Malignant Hyperthermia Susceptibility.

It is timely to consider the utility and practicability of screening for malignant hyperthermia susceptibility using genomic testing. Here the authors pose a simple, but bold question: what would it take to end deaths from malignant hyperthermia? The authors review recent advances and propose a scientific and clinical pathway toward this audacious goal to provoke discussion in the field.

Prevalence of malignant hyperthermia diagnosis in obstetric patients in the United States, 2003 to 2014.

Background: The cost-benefit of stocking dantrolene in maternity units for treating malignant hyperthermia (MH) has been recently questioned because of the low incidence of MH crisis in the general population and the low utilization of general anesthesia in obstetrics. However, no study has examined the prevalence of MH susceptibility in obstetrics. This study aimed to assess the prevalence of MH diagnosis and associated factors in obstetric patients.

Prevalence of malignant hyperthermia diagnosis in hospital discharge records in California, Florida, New York, and Wisconsin.

Study Objective: Malignant hyperthermia (MH) is a rare yet potentially fatal pharmacogenetic disorder triggered by exposure to inhalational anesthetics and the depolarizing neuromuscular blocking agent succinylcholine. Epidemiologic data on the geographic variation in MH prevalence is scant. The objective of this study is to examine the prevalence of recorded MH diagnosis in patients discharged from hospitals in four states in the United States.

Round Table on Malignant Hyperthermia in Physically Active Populations: Meeting Proceedings.

Context:   Recent case reports on malignant hyperthermia (MH)-like syndrome in physically active populations indicate potential associations among MH, exertional heat stroke (EHS), and exertional rhabdomyolysis (ER). However, an expert consensus for clinicians working with these populations is lacking.

Objective:   To provide current expert consensus on the (1) definition of MH; (2) history, etiology, and pathophysiology of MH; (3) epidemiology of MH; (4) association of MH with EHS and ER; (5) identification of an MH-like syndrome; (6) recommendations for acute management of an MH-like syndrome; (7) special considerations for physically active populations; and (8) future directions for research.

Early Development, Identification of Mode of Action, and Use of Dantrolene Sodium: The Role of Keith Ellis, Ph.D.

Dantrolene-a nitrofurantoin derivative-was developed by Snyder et al. in 1967. After initial discovery of its muscle relaxation potential, investigations in a number of species demonstrated dose-dependent reductions in skeletal muscle tone that were long lasting, relatively nontoxic, and free of adverse effects such as respiratory impairment.

Diversity and Similarity of Anesthesia Procedures in the United States During and Among Regular Work Hours, Evenings, and Weekends.

Background: Anesthesiologists providing care during off hours (ie, weekends or holidays, or cases started during the evening or late afternoon) are more likely to care for patients at greater risk of sustaining major adverse events than when they work during regular hours (eg, Monday through Friday, from 7:00 AM to 2:59 PM). We consider the logical inconsistency of using subspecialty teams during regular hours but not during weekends or evenings.

Methods: We analyzed data from the Anesthesia Quality Institute's National Anesthesia Clinical Outcomes Registry (NACOR).

A rare genetic variant of the ryanodine receptor in a suspected malignant hyperthermia susceptible patient.

Malignant hyperthermia (MH) remains a diagnostic challenge. This case report describes the anesthetic management of a suspected intraoperative MH episode and the subsequent, genetic sequence analysis of 3 genes associated with MH. The results of the molecular genetic testing revealed heterozygosity for a rare variant, c.

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).

Malignant hyperthermia: a review.

Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle that presents as a hypermetabolic response to potent volatile anesthetic gases such as halothane, sevoflurane, desflurane, isoflurane and the depolarizing muscle relaxant succinylcholine, and rarely, in humans, to stressors such as vigorous exercise and heat. The incidence of MH reactions ranges from 1:10,000 to 1: 250,000 anesthetics. However, the prevalence of the genetic abnormalities may be as great as one in 400 individuals.

Implications of National Anesthesia Workload on the Staffing of a Call Center: The Malignant Hyperthermia Consultant Hotline.

Recently, we analyzed data from the American Society of Anesthesiologist's (ASA) Anesthesia Quality Institute (AQI) to report the United States (U.S.) anesthesia workload by time of day and day of the week.

Malignant hyperthermia testing in probands without adverse anesthetic reaction.

Background: Malignant hyperthermia (MH) is triggered by reactions to anesthetics. Reports link nonanesthetic-induced MH-like reactions to a variety of disorders. The objective of the authors was to retrospectively investigate the reasons for referrals for MH testing in nonanesthetic cases and assess their phenotype.

Emergency Department Visits for Heat Stroke in the United States, 2009 and 2010.

Background: The effect of extreme heat on health has become a growing public health concern due to climate change. We aimed to examine the epidemiological patterns of hospital-based emergency department (ED) visits for heat stroke in the United States.

Findings: We analyzed data from the 2009 and 2010 Nationwide Emergency Department Sample, the largest ED data system sponsored by the Agency for Healthcare Research and Quality.

Accuracy of malignant hyperthermia diagnoses in hospital discharge records.

Background: In 1997, the International Classification of Diseases (ICD), 9th Revision Clinical Modification (ICD-9) coding system introduced the code for malignant hyperthermia (MH) (995.86). The aim of this study was to estimate the accuracy of coding for MH in hospital discharge records.

Malignant hyperthermia and the clinical significance of type-1 ryanodine receptor gene (RYR1) variants: proceedings of the 2013 MHAUS Scientific Conference.

The Malignant Hyperthermia Association of the United States and the Department of Anesthesia at the University of Toronto sponsored a Scientific Conference on November 1-2, 2013 in Toronto, ON, Canada. The multidisciplinary group of experts, including clinicians, geneticists, and physiologists involved in research related to malignant hyperthermia (MH), shared new insights into the pathophysiology of diseases linked to the type-1 ryanodine receptor gene (RYR1) as well as the relationship between MH and "awake MH" conditions, such as exertional rhabdomyolysis and exertional heat illness. In addition, the molecular genetics of MH and clinical issues related to the diagnosis and management of disorders linked to RYR1 were presented.