Heat Illness Rhabdomyolysis Sudden Cardiac Death Sickle Cell

Heat Illness Rhabdomyolysis Sudden Cardiac Death Sickle Cell Trait October 14 th, 2015 James Leinhart, MD

• • • AGENDA Definition Stats Mechanism Pathophysiology Risk Factors Diagnosis Management Recovery Prevention Questions

Heat Illness - Definition • • Heat Cramps Heat Tetany Heat Edema Heat Syncope / Exercise Associated Collapse (EAC) • Heat Exhaustion / Exertional Hyperthermia • Exertional Heat Stroke (EHS)

Heat Illness - Definition • Heat Cramps – Abdomen, lower extremities – Often yelling in pain – Fluid/electrolyte deficiency – Fatigue, faulty neuromuscular communication • Heat Tetany – Carpopedal spasm – Hyperventilation • Heat Edema – Hands, feet

Heat Illness - Definition • Heat Syncope / Exercise Associated Collapse (EAC) – Immediately upon cessation – Decreased vasomotor tone – Venous pooling – Dehydration

Heat Illness - Definition • Heat Exhaustion / Exertional Hyperthermia – Temperature < 104°F – No mental status changes – Weakness, dizziness, syncope, cramps, N/V • Exertional Heat Stroke (EHS) – Temperature > 104°F – AMS – Absent sweating – Seizures – Coma

Exertional Heat Stroke • Defined by hyperthermia (> 40°C) with CNS disturbances and multiorgan failure. • Almost all exhibit sweat soaked and pale skin at time of collapse • In contrast, non-exertion related heatstroke presents with dry, hot and flushed skin.

Exertional Heat stroke • Predisposing factors – Strenuous exercise in a hot humid environment – Lack of heat acclimatization – Poor physical fitness • Greatest risk when the wet bulb globe temperature exceeds 28°C (82°F) during high intensity exercise (>75% VO 2 max) and/or strenuous exercise that lasts longer than 1 hour. • EHS can occur in cool to moderate environments

Heat Illness - Stats • Incidence – Varies based on event – Highly dependent on environmental conditions – Limited reporting on non-fatal EHS • Football – Since 1995, average 3 deaths/year – 1/350, 000 • Marathon – 1/10, 000 finishers

Exertional Heat Stroke • Factors that increase risk – – – Obesity Low physical fitness Lack of heat acclimatization Dehydration Previous history of EHS Sleep deprivation Sweat gland dysfunction Sunburn Viral illness Diarrhea Alcohol/drugs Certain medications

Heat Illness – Mechanism/Pathophysiology • As a cell is heated above it’s thermal threshold (about 40°C) • Cellular damage – Protein denaturation – Cell dysfunction->organ dysfucntion • Inflammatory Cytokines / Heat Shock Proteins – Circulatory collapse / shock – Systemic / end organ damage • Vascular Endothelium Damage – coagulopathies

Exertional Heat Stroke • Recognition – Immediate recognition is paramount to survival – Signs and symptoms generally nonspecific. • Disorientation, confusion, dizziness, irrational or unusual behavior, inappropriate comments, headache, irritability, loss of balance and muscle function, vomiting, collapse, hyperventilation, seizures and coma – Rectal Temperature should be measured: >40°C (104°F) – SBP<100 mm Hg, Tachycardia, hyperventilation and shock-like appearance are common.

Heat Illness – Diagnosis • Signs/Symptoms – Core (rectal, foley) temperature > 104°F – Impaired cardiac output • Hypotension, tachycardia, tachypnea – AMS • Irritability, ataxia, confusion, disorientation, syncope, hysteria, psychosis, seizure, coma – Diminished peripheral cooling • Decreased perspiration, hot skin – DIC • Bleeding, ecchymosis, pulmonary edema – ARF metabolic abnormalities

Exertional Heat Stroke • Treatment – A life- threatening medical emergency that requires immediate whole body cooling. – Cold water cooling provides the fastest whole body cooling rate and the lowest morbidity and mortality. – If unavailable-> ice water, towels/sheets with ice on head, trunk extremities etc… – Hematological and serum chemistry should be obtained if possible. – Fluids to preserve intravascular volume, improves renal flow and protects kidneys from Rhabdomyolysis

Exertional Heat Stroke • Return to play – Refrain from exercise for at least 7 days. – Follow up in one week for physical exam and repeat lab testing or diagnostic imaging of affected organs. – When cleared, begin exercise in a cool environment and gradually increase duration, intensity, heat exposure for 2 weeks to acclimatize and demonstrate tolerance – If return to activity is difficult, consider a laboratory exercise-heat tolerance test about 1 month postincident. – Clear the athlete for full competition if heat tolerance exists after 2 -4 weeks of training.

Heat Illness – Recovery • Increased susceptibility to EHS after acute event – Impaired central thermoregulation up to several months • At least 7 days asymptomatic rest • Graduated return to activity protocol – Stepwise over two weeks – Supervised

Heat Illness - Question • During the second football practice of the day on day three of the college preseason football camp, an offensive lineman is found sitting on the ground, unwilling to stand up. He states his left calf is cramping and that he feels lightheaded and exhausted. You suspect possible exertional heat stroke. Which of the following statements about this condition is true? A. Axillary, oral, or a rectal temperature greater than 104 F (40 C) establishes the diagnosis of exertional heat stroke B. This condition occurs randomly without warning and cannot be predicted C. Cold/ice water immersion is an effective way to treat exertional heat stroke D. There are two patterns of presentation: sodium depletion and water depletion

Rhabdomyolysis • In athletics most cases exertional but can be caused by crush injuries, burns and multiple other causes. • Prolonged, heavy repetitious exercise leads to breakdown of skeletal muscle and leakage of cellular contents. • Etiology: local tissue hypoxia leading to failure of cellular function and potassium efflux and calcium influx • Common predisposing factors: Heat, humidity, dehydration, poor conditioning.

Rhabdomyolysis • Presentation: Muscle pain and tenderness, muscle swelling, muscle cramps, reddish brown urine. • Most cases are subclinical and never diagnosed • Labs: CK is the most important diagnostic enzyme. Rhabdo defined as greater than 5 times the upper limit of normal or 1000. – – <200= nml >600= subclinical to mild >10, 000= most clinical cases >200, 000= severe

Rhabdomyolysis • Mild to moderate – Respond well to aggressive hydration – Damage not persistent • Severe cases – Acute Tubular Necrosis: Caused by renal hypoperfusion, acidosis, and myoglobin sludging in renal tubules. – Acute Compartment Syndrome: – Rhabdo causes muscle swelling which increases intramuscular pressure – Athletes with chronic compartment syndrome: increased pressures and decreased tissue perfusion leads to Rhabdo

Treatment • Aggressive early hydration – Maintains renal perfusion, clears myoglobin and prevents ATN. – May require 4 -12 L NS in first 24 hours. – Urine output goal 3 ml/kg/hr • Alkalinization of urine with bicarbonate – Myoglobin is less nephro toxic in alkaline urine • Correct electrolyte abnormalities – Caution hyperkalemia and cardiac dysrhythmias • Fasciotomy if necessary

Rhabdomyolysis • Ongoing care – – Repeat CK, elctrolytes and renal function in a few days CK goal below 1000 Discontinue myotoxic drugs if any Activity as tolerated after normalization of labs • Diet – When rhabdo causes renal failure restrict protein intake to lower BUN – Limit potassium intake if renal failure

Sudden Cardiac Death - Question • A 19 -year-old female tennis player comes to you for her preparticipation examination. She denies any cardiac symptoms and has always kept up with her peers. There is no history of heart disease or early death in the family. Examination is unremarkable except for a systolic ejection murmur that increases with Valsalva and standing, and decreases with fist clenching and squatting. Which of the following is the most significant predictor of sudden cardiac death in this athlete? A. B. C. D. E. Sudden death in her brother Muscle fiber disarray on biopsy Septal thickness > 1. 8 cm Paroxysmal atrial fibrillation on Holter monitoring Resting BP 120/75, and BP 95/70 after six minutes of exercise

Sudden Cardiac Death - Question • Which of the following is a current American Heart Association (AHA) recommendation regarding cardiac evaluation during the preparticipation exam? A. B. C. D. Auscultate for heart murmur during provocative maneuvers Palpate bilateral brachial pulses Obtain bilateral brachial blood pressure with the athlete standing Perform electrocardiogram on all athletes

Sudden Cardiac Death - Definition • An unexpected death due to cardiac causes occurring in a short time period (generally within 1 h of symptom onset) in a person with known or unknown cardiac disease.

Cardiac

Sudden Cardiac Death • Structural – HOCM (25 -36%) – CCA (19%) – MVP – Aortic Rupture (marfans) – AS – myocarditis – CAD (age >30) • Electrical – LQTS – SQTS – WPW – Brugada – AV blocks • Traumatic – Commotio Cordis (20%)

Cardiac • In a collapsed athlete, cardiac arrest should be assumed until proven otherwise • Time from arrest to defibrillation is the single greatest factor affecting survival – Survival rates decrease 10% for every minute defibrillation is delayed w/o CPR. – Decreases to 3 -4% if CPR is administered. • Drezner et al – Demonstrated high survival rates for sudden cardiac deaths for high schools with AED programs. – 16/18 (89%) student athletes and 8/9 (89%) adults who arrested during physical therapy – Survival wo AED’s is approximately 8%

Cardiac • Presentation – Brief seizure-like activity with myoclonic movements have been reported in over 50% of athletes with cardiac arrest. – Agonal respirations or gasps are often mistaken for normal breathing • Treatment – Activate EMS, attach AED if available – ABC vs CAB • More emphasis on chest compressions (30: 2) rather than rescue breathing. • Less emphasis on checking pulses

HOCM – Mechanism/ Pathophysiology • Asymmetric LV hypertrophy – Septum – Thickness > 15 mm – Septum: Free Wall > 1. 3 – Nondilated LV – Disorganized cellular architecture – 1/3 cases with coronary intramural tunneling – LV diastolic dysfunction – Dynamic outflow obstruction – Ventricular arrhythmias

HOCM – Mechanism/ Pathophysiology • Genetics – 11 mutated sarcomeric genes – 55% autosomal dominant – 45% sporadic

HOCM – Diagnosis • Symptoms – Usually asymptomatic until death – Only 21% have prior symptoms • Exertional CP, lightheadedness, dyspnea, syncope • PPE – Athlete Hx – FH SCD in family members < 35 years old – PE • Harsh systolic ejection murmur – Increases with decreased venous return (valsalva, standing) – Diminishes with increased venous return (supine, squatting)

HOCM – Diagnosis • ECG – 95% abnormal • Prominent Q waves • Deep inverted T waves • Increased QRS voltage • Echocardiography – Gold standard

HOCM – Diagnosis

HOCM – Management • PPE – Hx, FH SCD, PE – ECG, TTE if indicated • Class IA sports only (low-static, low-dynamic) – Bowling, golf, etc. • Informed consent • AED • ICD

Commotio Cordis

Sudden Cardiac Death - Question • A 19 -year-old female tennis player comes to you for her preparticipation examination. She denies any cardiac symptoms and has always kept up with her peers. There is no history of heart disease or early death in the family. Examination is unremarkable except for a systolic ejection murmur that increases with Valsalva and standing, and decreases with fist clenching and squatting. Which of the following is the most significant predictor of sudden cardiac death in this athlete? A. B. C. D. E. Sudden death in her brother Muscle fiber disarray on biopsy Septal thickness > 1. 8 cm Paroxysmal atrial fibrillation on Holter monitoring Resting BP 120/75, and BP 95/70 after six minutes of exercise

Sudden Cardiac Death - Question • Which of the following is a current American Heart Association (AHA) recommendation regarding cardiac evaluation during the preparticipation exam? A. B. C. D. Auscultate for heart murmur during provocative maneuvers Palpate bilateral brachial pulses Obtain bilateral brachial blood pressure with the athlete standing Perform electrocardiogram on all athletes

Sickle Cell Trait – Question • Which of the following statements regarding sickle cell trait athletes is true? A. Sickle cell trait, in contrast to sickle cell disease, has little to no mortality in athletes B. Any cramping, struggling, or collapse in a sickle-trait athlete must be considered sickling – a medical emergency – until proven otherwise C. The symptoms of exertional sickling and heat illness are not distinguishable D. Acclimation to intense training, increased hydration, and increased rest afford no protection to sickling in athletes

Sickle Cell Trait – Question • A 20 year-old-male football player with known sickle cell trait slumps to the ground complaining of diffuse muscle fatigue. His ABCs are intact and his core temperature is 101°F. What is the best initial form of treatment? A. B. C. D. Intravenous fluids Stretching and massage of affected muscles Cold/ice water immersion Oxygen 15 L via NRB

Sickle Cell Trait – Definiton • Condition in which normal hemoglobin A and abnormal hemoglobin S are produced

Sickle Cell Trait – Stats • More common in people of African American and Mediterranean descent • Originally spontaneous mutation – Possible protective benefit against malaria • 5% to 8% African American population – About 1 in 12 – 2 million people in US

Sickle Cell Trait – Mechansim/ Pathophysiology • No effect on exercise capacity • Extreme exercise conditions can induce sickling, increase deoxygenated hemoglobin levels, impair RBC perfusion, lead to ischemia – – – Acidosis Hypoxia Dehydration Altitude Asthma Illness

Sickle Cell Trait

Sickle Cell Trait – Diagnosis • NCAA mandated testing (2010) – Hemoglobin electrophoresis • Signs/Symptoms – Muscle fatigue with +/- cramping • Usually early in workout • Characteristic slump to the ground – “sickling collapse” – Abdominal pain • Splenic infraction – Hematuria – Rhabdomyolysis – ARF – Metabolic abnormalities

Sickle Cell Trait – Management • Prevention – Acclimitization – Gradual work-out progression – Hydration • Treatment – ABCs – High flow oxygen – 15 L NRB – Cool the athlete – IVF – Transport to ED

Sickle Cell Trait – Question • Which of the following statements regarding sickle cell trait athletes is true? A. Sickle cell trait, in contrast to sickle cell disease, has little to no mortality in athletes B. Any cramping, struggling, or collapse in a sickle-trait athlete must be considered sickling – a medical emergency – until proven otherwise C. The symptoms of exertional sickling and heat illness are not distinguishable D. Acclimation to intense training, increased hydration, and increased rest afford no protection to sickling in athletes

Sickle Cell Trait – Question • A 20 year-old-male football player with known sickle cell trait slumps to the ground complaining of diffuse muscle fatigue. His ABCs are intact and his core temperature is 101°F. What is the best initial form of treatment? A. B. C. D. Intravenous fluids Stretching and massage of affected muscles Cold/ice water immersion Oxygen 15 L via NRB

Algorithm for Collapsed Athlete • Wen et al, 2014

Conclusion • Cardiac - Very sudden, no cramping, usually unresponsive, +/- Seizure activity. • Rhabdo – Cramping, muscle aches, reddish urine, normal mental status • Exercise-associated collapse – Athlete collapses either immediately upon crossing the finish line or within a few moments after finishing • Heat Illness – CNS changes (confusion, delerium, stupor, seizures or coma) – Often with heat cramping- rock hard muscles, writhing and yelling in pain • Sickling – Usually early in workout, increasing pain and weakness in working muscles

References

Questions?