Multifactorial Origin of Exertional Rhabdomyolysis, Recurrent Hematuria, and Episodic Pain in a Service Member with Sickle Cell Trait.

Individuals with Sickle Cell Trait (SCT), generally considered a benign carrier state of hemoglobin S (HbAS), are thought to be at risk for exertional rhabdomyolysis and hematuria, conditions that can also be caused by various other acquired and inherited factors. We report an SCT positive service member with an exertional rhabdomyolysis event, recurrent hematuria with transient proteinuria, and episodic burning pain in the lower extremities. Clinical and genetic studies revealed the multifactorial nature of his complex phenotype.

Pathogenic and rare deleterious variants in multiple genes suggest oligogenic inheritance in recurrent exertional rhabdomyolysis.

Exertional rhabdomyolysis is a metabolic event characterized by the release of muscle content into the circulation due to exercise-driven breakdown of skeletal muscle. Recurrent exertional rhabdomyolysis has been associated with metabolic myopathies and mitochondrial disorders, a clinically and genetically heterogeneous group of predominantly autosomal recessive, monogenic conditions. Although genetics factors are well recognized in recurrent rhabdomyolysis, the underlying causes and mechanisms of exercise-driven muscle breakdown remain unknown in a substantial number of cases.

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.

Malignant Hyperthermia Susceptibility and Fitness for Duty.

Introduction: Malignant hyperthermia (MH) is an inherited hypermetabolic condition characterized by uncontrolled calcium release from the sarcoplasmic reticulum of skeletal muscle, usually from exposure to inhaled general anesthetics and/or the depolarizing neuromuscular blocking agent succinylcholine. Multiple case reports now reveal that crises may be precipitated by environmental factors such as exercise or high ambient temperatures. Common signs of an MH crisis include life-threatening hyperthermia, metabolic acidosis, muscle rigidity, and tachycardia.

Improving awareness of nonanesthesia-related malignant hyperthermia presentations: a tale of two brothers.

A 30-year-old man developed unexplained rhabdomyolysis, persistently increased creatine kinase and severe debilitating muscle cramps. After a nondiagnostic neurologic evaluation, he was referred for a muscle biopsy, to include histology/histochemistry, a myoglobinuria panel, and a caffeine halothane contracture test. Only the caffeine halothane contracture test was positive, and a subsequent ryanodine receptor type 1 gene evaluation revealed a mutation functionally causative for malignant hyperthermia.

Multiacquisition T1-mapping MRI during tidal respiration for quantification of myocardial T1 in swine with heart failure.

Objective: The purpose of this article is to evaluate a free-breathing pulse sequence to quantify myocardial T1 changes in a swine model of tachycardia-induced heart failure.

Materials And Methods: Yorkshire swine were implanted with pacemakers and were ventricularly paced at 200 beats/min to induce heart failure. Animals were scanned twice with a 1.

Genetic polymorphisms associated with exertional rhabdomyolysis.

Exertional rhabdomyolysis (ER) occurs in young, otherwise healthy, individuals principally during strenuous exercise, athletic, and military training. Although many risk factors have been offered, it is unclear why some individuals develop ER when participating in comparable levels of physical exertion under identical environmental conditions and others do not. This study investigated possible genetic polymorphisms that might help explain ER.

Case report: Death in the emergency department: an unrecognized awake malignant hyperthermia-like reaction in a six-year-old.

A healthy 6-year-old boy developed lower extremity rigidity, trismus, and fever after playing in a splash pool. On arrival in the emergency department, he appeared to be seizing. An endotracheal tube was emergently placed using succinylcholine.

The relationship between exertional heat illness, exertional rhabdomyolysis, and malignant hyperthermia.

Exertional heat illness, exertional rhabdomyolysis, and malignant hyperthermia (MH) are complex syndromes with similar pathophysiology. All three are hypermetabolic states that include high demand for adenosine triphosphate, accelerated oxidative, chemical, and mechanical stress of muscle, and uncontrolled increase in intracellular calcium. Although there are no controlled clinical studies to support a relationship, there is evidence to suggest an association between unexpected heat/exercise intolerance and MH susceptibility.

Methadone-induced mortality in the treatment of chronic pain: role of QT prolongation.

Methadone is increasingly prescribed for chronic pain, yet the associated mortality appears to be rising disproportionately relative to other opioid analgesics. We review the available evidence on methadone-associated mortality, and explore potential pharmacokinetic and pharmacodynamic explanations for its greater apparent lethality. While methadone shares properties of central nervous system and respiratory depression with other opioids, methadone is unique as a potent blocker of the delayed rectifier potassium ion channel (IKr).

Trauma, systemic inflammatory response syndrome, dietary supplements, illicit steroid use and a questionable malignant hyperthermia reaction.

Background: Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle calcium regulation associated primarily, but not exclusively, with mutations in the skeletal muscle ryanodine receptor. Associated environmental factors, however, may also be important for expression of the syndrome.

Methods And Results: A 24-yr-old trauma patient developed a fulminant MH crisis after a 3 minute exposure to sevoflurane.

Anesthesia services aboard USNS COMFORT (T-AH-20) during Operation Iraqi Freedom.

USNS COMFORT (T-AH-20), the only U.S. hospital ship to be deployed in support of combat operations during Operation Iraqi Freedom, sailed from Baltimore, Maryland, on January 6, 2003, and returned on June 12, 2003.