INTRODUCTION:The prevalence of sickle cell trait is 8 percent in the African-American population. There is a strong correlation of sudden death and sickle cell trait among young men in military training and organized sports. Risk factors for sudden death associated with sickle cell trait have been identified as heavy exercise with poor physical conditioning, dehydration, increased ambient temperature and training at high altitudes.We present a case of fatal rhabdomyolysis in a freshman college athlete with sickle cell trait without identifiable risk factors.
CASE PRESENTATION:A 19 year old African American football player presents to the emergency center after collapsing on the field. He was a well conditioned athlete undergoing a team workout regimen which consisted of weightlifting and wind sprints. He underwent a light workout keeping hydrated when he approached the field trainer complaining of dizziness and shortness of breath. He had labored breathing and depressed level of consciousness which rapidly progressed to respiratory collapse and unresponsiveness. Upon EMS arrival, he had a Glascow Coma Score of three, temperature 98.8, blood pressure 100/70, heart rate 60, respiratory rate 6, and pulse oximetry saturation 62% on ambient air. Nasotracheal intubation was performed. History revealed no past medical or surgical history, no alcohol, tobacco, or illicit drug use, no use of performance enhancing agents. The physical examination on admission to the MICU was pertinent for musculoskeletal examination revealing rigid legs which could not be passively flexed at the joints. Neurological examination remained unchanged. Initial laboratory data: Na 148, K 5.2, HCO3 8, Cr 2.3, Ca 8.6, Mg 5.7, PO4 12.8, ALT 440, AST 388, Lactic Acid 33; CK 536, CK-MB 17.5, Troponin-T 0.017, Myoglobin 7485; WBC 9,700, Hemoglobin 14.5, Platelet 149,000; PT 22.6, INR 2.77, PTT 83.7; Urine Drug Screen negative. CXR normal. EKG demonstrated sinus tachycardia with peaked T-waves in the precordial leads. Labs two hours after presentation: potassium 7.1. Despite hemodialysis, severe hyperkalemia persisted at 9.0, CK >41,000 and lactic acid 18.4 He developed epistaxis and bleeding from venipuncture sites with lab evidence of disseminated intravascular coagulation and hemoglobin 4.3. Blood products were aggressively transfused. His legs remained completely rigid throughout his course. He was chemically paralyzed with no effect on his course. A second hemodialysis unit was initiated to assist in the management of severe hyperkalemia. All supportive measures were futile and the patient experienced irreversible cardiovascular collapse 14 hours after presentation. Autopsy revealed evidence of microscopic changes indicative of acute degeneration of skeletal muscle, microscopic visceral congestion with evolving ischemic change, sickle cell trait with Hemoglobin S at 41.3 % and DIC.
DISCUSSIONS:As in the homozygous state, complications due to the heterozygous sickle cell trait are a result of polymerization of deoxygenated hemoglobin S which produces vaso-occlusion. Physiologic conditions due to hypoxia, acidosis, dehydration, hyperosmolality, or other metabolic derangements can result in vaso-occlusive disease. A cohort study by Kark among military recruits determined the risk of exercise-related death for sickle cell trait was 28-fold higher. The risk factors identified include heavy exercise with poor physical conditioning, dehydration, increased ambient temperature and training at high altitudes. This case is of a well conditioned athlete who underwent a light workout at sea level prior to collapse.
CONCLUSION:A strong correlation of increased morbidity and mortality from exertional rhabdomyolysis exists in those undergoing physical training having sickle cell trait. Athletes should be screened and counseled on risk factors and early signs of distress.
DISCLOSURE:Rajesh Harrykissoon, None.