Heat illness, exertional collapse and sudden death prevention — formative SAQs

SAQ 1 (10 marks) — The sixteen-year-old runner who collapses confused at the eight-kilometre mark

Stem: A sixteen-year-old cross-country runner collapses at the eight-kilometre mark of an August race on a hot humid morning. At the field side she is confused and combative, her skin is hot, and a rectal thermistor reads 41.2 degrees Celsius. The athletic trainer has a cold-water immersion tub ready. Outline your assessment, immediate management, and the prevention that should have preceded the race. [1] [2]

Model answer

Assessment and diagnosis (2 marks). This athlete has exertional heat stroke, defined by a core (rectal) temperature of 40 degrees Celsius or higher accompanied by central nervous system dysfunction. The confusion and the combativeness are the central nervous system signs, the hot skin supports the diagnosis, and the rectal temperature of 41.2 degrees Celsius confirms it. The pulse was checked first because an athlete without a pulse has sudden cardiac arrest, and the rectal thermistor — not the tympanic, oral, or skin reading — is the only valid field measure of the core temperature. The diagnosis is made at the field side and the cooling begins at once. [1]

Immediate management (5 marks). The treatment of choice is cold-water immersion, begun before any transport is arranged, under the cool-first-transport-second rule. The athlete is immersed to the neck in a tub of cold water at 2 to 15 degrees Celsius, the water is stirred continuously to maintain the cooling gradient, and the rectal temperature is monitored throughout. The cold-water immersion achieves the fastest cooling rate of any field method, approximately 0.15 to 0.35 degrees Celsius per minute, and the goal is a rectal temperature below 39 degrees Celsius (around 102 degrees Fahrenheit) before the transport. The survival approaches one hundred per cent when the cooling begins within minutes, and the DeMartini Falmouth Road Race series anchors this near-complete survival. The airway is supported, the vomiting is anticipated, the shivering is suppressed because it generates heat, and the intravenous fluids are given for the hypotension. The transport is arranged only after the temperature is controlled. [2] [1]

Hospital and disposition (1 mark). The athlete is transported to the emergency department for the monitoring of the hepatic, renal, coagulation, and neurological complications, and the support is given as the multi-organ picture demands. The bloods include the electrolytes, the creatine kinase, the liver function tests, and the coagulation profile. [1]

Prevention that should have preceded the race (2 marks). The prevention rests on the four pillars: a fourteen-day heat-acclimatization protocol, the wet-bulb globe temperature activity modification, the hydration without overhydration, and the rehearsed emergency action plan. The wet-bulb globe temperature combines the heat, the humidity, the radiant heat, and the wind, and the intense activity is modified as it rises. The unrestricted access to fluids, the attentive supervision, and the empowered athletic trainer who removes the struggling athlete are the safeguards, and the cold-water immersion tub and the rehearsed team are the preparedness that this venue demonstrated. [1] [9]

SAQ 2 (10 marks) — The seventeen-year-old who collapses pale and alert at the finish line

Stem: A seventeen-year-old runner crosses the finish line of a five-kilometre run on a warm day and immediately slumps to the ground. At the field side she is pale, sweaty, and pulse-weak but fully alert and oriented once she lies down. Her rectal temperature is 37.8 degrees Celsius and her pulse settles within three minutes of rest with the legs elevated. Outline your assessment, management, the differentials you must exclude, and your return-to-play advice. [5] [1]

Model answer

Assessment and diagnosis (2 marks). This athlete has exercise-associated collapse, the benign collapse that occurs when a runner stops and the calf-muscle pump ceases, allowing the venous pooling and the transient drop in the cerebral perfusion. The preserved mental state that clears once supine, the normal rectal temperature of 37.8 degrees Celsius, and the rapid recovery of the pulse are the defining features. The pulse was checked first to exclude the sudden cardiac arrest, and the rectal thermistor was taken to exclude the exertional heat stroke, because the field-side protocol runs the collapse in the order of the life threat. [5]

Management (2 marks). The management is rest in the supine position with the legs elevated to restore the venous return, and the oral rehydration as the athlete tolerates it. The vital signs and the mental state are monitored, and the athlete recovers within minutes. The intravenous fluids are reserved for the athlete who is hypotensive or unable to tolerate the oral fluids. The athlete is observed for the delayed deterioration before the discharge. [5]

Differentials to exclude (4 marks). The exertional heat stroke is excluded by the rectal temperature below 40 degrees Celsius and the preserved mental state, but the athlete who deteriorates or whose temperature climbs is reassessed and managed as the heat stroke with the cold-water immersion. The exercise-associated hyponatraemia is considered in the endurance athlete who drank far more than the sweat loss, presenting with the confusion, the nausea, the vomiting, and the seizures, sometimes with the weight gain, and the management is the fluid restriction and the hypertonic saline rather than the free-water rehydration. The sudden cardiac arrest is excluded by the confirmed pulse and the rapid recovery. The exertional rhabdomyolysis and the sickle-cell crisis are considered when the muscle pain and the dark urine follow. The key skill is to run the collapse as a short list separated at the field side by the pulse, the temperature, and the mental state. [1] [5]

Return-to-play advice (2 marks). The athlete returns to the activity after the full recovery, the correction of the risk factors, and the education on the hydration, the acclimatization, and the recognition of the early signs. The athlete is advised to drink to the thirst and the sweat loss rather than a prescribed large volume, to acclimatize over the fourteen-day protocol in the heat, and to report the early symptoms. The safety-net is the instruction to return if any collapse, confusion, or deterioration occurs. [1]