Cool Your Jets Bro

ABSTRACT

History Twenty-two year old male basic trainee was brought to the ED after collapsing during a routine ruck march. At mile 8/12, soldier was noted to develop an unsteady gate and had witnessed loss of consciousness. A rectal core temperature was obtained and noted to be >107degreeF. Cooling initiated with ice sheets and EMS was activated. On arrival to the ED, patient demonstrated confusion and persistently elevated core temperatures despite ice sheeting, chilled saline and cold water bladder lavage. Cooling measures were discontinued after patient achieved euthermia in the ED;however, his temperatures subsequently spiked>103degreeF. Given rebound hyperthermia, an endovascular cooling (EVC) device was placed in the right femoral vein and patient was transferred to the ICU. Multiple attempts to place EVC device on standby were unsuccessful with subsequent rebound hyperthermia. Prolonged cooling was required. Physical Exam VS HR 121, BP 85/68, RR 22 SpO2 100% RA, Temp 102.4degreeF Gen young adult male, NAD, shivering, A&Ox2 (person and place only) HEENT Scleral anicteric, conjunctiva non-injected, moist mucus membranes Neck Supple, no LAD Chest CTAB, no wheezes/rales/rhonchi CV tachycardia, regular rhythm, normal S1, S2 without murmurs, rubs, gallops ABD NABS, soft/non-distended, no guarding or rebound EXT No LE edema, tenderness SKIN blisters with broad erythematous bases on bilateral heels Neuro CN II-XII grossly intact, 5/5 strength in all extremities. Differential Diagnosis 216. Septic Shock 217. Hypothalamic Stroke 218. Exertional Heat Stroke (EHS) 219. Neuroleptic Malignant Syndrome 220. Thyroid Storm Test Results: CBC 18.2>14.5/40.6<167 CMP 128/3.5 88/1831/2.7<104, AST 264, ALT 80, Ca 8.8 Lactate 7.1 CK 11 460 Myoglobin 18 017 TSH 3.16 CXR No acute cardiopulmonary process Blood Cx negative x2 CSF Cx Negative COVID/Influenza/EBV Negative Brain MRI wnl. Final Diagnosis Exertional Heat Stroke. Discussion(s) No EVC protocols exist for the management of EHS or rebound/refractory hyperthermia. As a result, the protocol used for this patient was adapted from post-cardiac arrest cooling protocols. It is unclear if this adapted protocol contributed to his delayed cooling and rebound hyperthermia as it was not intended for this patient demographic/ pathophysiology. Furthermore, despite initiating empiric antibiotics upon admission, delayed recognition and tailored therapy for his bilateral ankle cellulitis may have contributed to the difficulty in achieving euthermia. In summary, more research needs to be done to evaluate and develop an EVC protocol for EHS. Outcome(s) Euthermia was achieved and maintained after 36 hours of continuous EVC, at which point it was discontinued. His CK, AST/ALT, creatinine and sodium down-trended after discontinuation of EVC. Patient's antibiotics were transitioned to an oral formulation for treatment of ankle cellulitis and he was prepared for discharge. He was discharged with regular follow-up with the Fort Benning Heat Clinic. Follow-Up After discharge, patient had regularly scheduled visits with the Fort Benning Heat Clinic. His typical lab markers for exertional heat stroke were regularly monitored. He had continued resolution of his Rhabdomyolysis, acute kidney injury and hyponatremia with typical treatment. Soldier returned to duty after 10 weeks of close monitoring and rehabilitation.