Hyperthermia Flashcards
Presentation of heat related illness
Typically temperature exceeds 40C
Tachycardia
Commonly normotensive, but may be hypotensive
Severe CNS dysfunction
Pupils may be fixed, dilated, pinpoint or normal
Nystagmus or oculogyric episodes may be present
Typically hyperdynamic cardiovascular state
Hypodynamic state signifies impending CV collapse
Tachypnea and hyperventilation
Gastrointestinal hemorrhage occurs frequently
Jaundice and elecated liver enzymes occurs commonly
Fulminant hepatic failure and DIC rarely occur
Muscle tenderness and cramping are common
Rhabdomyolysis and ARF are common complications of EHS
Heatstroke definition
hyperthermia usually greater than 40 C associated with severe CNS dysfunction and anhidrosis and has a mortality rate of up to 70%
Classic heatstroke
typically occurs during environmental heat waves as a result of the body’s failure to dissipate heat
very young, the elderly, and the chronically and mentally ill
sweating usually ceases
Severe CNS symptoms
Exertional heatstroke
young healthy individuals who are unable to dispel heat due to endogenous heat production
3rd leading cause of death for high schoolers
Hyperthermia and DIAPHORESIS
Cocaine or amphetamines that increase muscle movement. Also seizures
What are exertion heatstroke patients more likely to develop compared to classic heatstroke patients?
rhadomyolysis, acute renal failure, coagulopathy, lactic acidosis, and hypoglycemia
What is prickly heat?
pruritic vesicles in the clothed areas that extend producing deeper vesicles that are less pruritic.
caused by blockage of the sweat glands and a secondary staph infection.
What is heat exhaustion?
malaise, fatigue, nausea, vomiting, weakness and headache in the setting of heat stress. The core temperature is frequently normal or just mildly elevated
What is heat syncope?
Usually in the elderly
temporary loss of consciousness caused by intravascular shunting to the cutaneous circulation, pooling in the lower extremities due to prolonged standing, and volume depletion
What is heat edema?
edema of the feet and ankles in unacclimatized individuals exposed to warm tropical or subtropical climates. It is thought to be the result of increased hydrostatic pressure and vasodilation resulting in vascular leak and edema.
What are heat cramps?
brief, intermittent, severe cramps in muscles fatigued by excessive exercise and occur at a time of rest. They are thought to be related to salt deficiency and usually occur in the first days of excessive work in a hot, humid environment.
Myoglobin and Renal Function
Renal function is critically important to evaluate since patients with muscle necrosis release myoglobin which is nephrotoxic. Without appropriate treatment, permanent renal damage may result.
How does Dantrolene work?
Decreased intracellular calcium levels lead to reduced muscle metabolic activity and heat production.
Treatment with Dantrolene
malignant hyperthermia and neuroleptic malignant syndrome, but its utility and effectiveness in heatstroke is controversial.
Why is shivering bad in Hyperthermia situations?
Shivering leads to increased heat production and should be controlled with benzodiazepines.
What are the classic findings of rhabdomyolysis?
Dark tea colored urine and tender muscles are classic findings
