With respect to heat stroke:
a) Outline the pathophysiology. (20% marks)
b) List the factors that affect prognosis. (10% marks)
c) List the expected changes on routine investigations in the presence of heat stroke. (20% marks)
d) Outline the management of a patient with heat stroke. (50% marks)
Uncoupling of oxidative phosphorylation
Failure of enzyme systems
increased Na leak into cells
Sweat gland damage from heat
Prognosis depends on core temp, duration of hyperthermia and presence of comorbidities.
Haemoconcentration (dehydration), haemolysis
LFT derangements (cholestatic, early sign),
DIC often delayed onset and a/w worse prognosis
CK rise (exertional type),
During treatment: CXR pulmonary oedema (centralise fluid, ALI), low PO4, Ca, glucose,
ABC (Airway protection if GCS low etc. ) & control of seizures if present
Remove from offending environment,
Rapid cooling to 39 C (duration of hyperthermia major determinant of outcome): remove clothing, sponge cold water, ice, fans, cooling blankets, cold intravenous fluids gastic lavage with cold solutions, immersion (young and military), cold dialysis, etc. Monitor core temp closely
Volume and electrolyte resuscitation and close monitoring
Eectrolytes. NB Risk of cerebral oedema
In general there was a knowledge deficit relating to the pathophysiology of heat stroke. Some candidates failed to address cooling and control of temperature in the management of heat stroke and did not recognise the need for initial rapid cooling and/ or the need for careful temperature monitoring.
a) Pathophysiology of heat stroke:
b) Factors that affect prognosis of heat stroke:
c) List the expected changes on routine investigations in the presence of heat stroke.
d) Outline the management of a patient with heat stroke.
Bouchama, Abderrezak, and James P. Knochel. "Heat stroke." New England Journal of Medicine 346.25 (2002): 1978-1988.
Grogan, H., and P. M. Hopkins. "Heat stroke: implications for critical care and anaesthesia." British Journal of Anaesthesia 88.5 (2002): 700-707.
Glazer, James L. "Management of heatstroke and heat exhaustion." Am Fam Physician 71.11 (2005): 2133-2140.
Bricknell, M. C. "Heat illness--a review of military experience (Part 1)." Journal of the Royal Army Medical Corps 141.3 (1995): 157-166.
Bricknell, M. C. M. "Heat illness-A review of military experience (Part 2)." Journal of the Royal Army Medical Corps 142.1 (1996): 34-42.
Leon, Lisa R., and Bryan G. Helwig. "Heat stroke: role of the systemic inflammatory response." Journal of applied physiology 109.6 (2010): 1980-1988.
Alzeer, Abdulaziz H., et al. "Serum enzymes in heat stroke: prognostic implication." Clinical chemistry 43.7 (1997): 1182-1187.
Bouchama, Abderrezak, Mohammed Dehbi, and Enrique Chaves-Carballo. "Cooling and hemodynamic management in heatstroke: practical recommendations." Crit Care 11.3 (2007): R54.
Misset, Benoît, et al. "Mortality of patients with heatstroke admitted to intensive care units during the 2003 heat wave in France: A national multiple-center risk-factor study*." Critical care medicine 34.4 (2006): 1087-1092.