R1iv: Physiological Consequences of Hyperthermia
Define:
Hyperthermia = when core body temperature exceeds tight regulatory control by thermoregulation (Core Body Temp > 37.5°C)
Heat Stroke = severe hyperthermia (Core Body Temp > 40.6°C )dry skin, loss of consciousness)
Physiological Consequences
CNS
- Altered conscious levels
- Delerium, lethargy, coma, seizures
- NaCl depletion 2 sweating (at maximum 2L/hr)
CVS
- ↑CO, ↑HR, ↓SVR
- QT prolongation
- ST segment changes
- Myocardial infarction
- Hypotension 2 volume depletion & VD
METABOLIC
- ↑BMR
- ↑O2 consumption
- Lactic acidosis
- Resp Alkalosis
RESP
- Respiratory failure/ ARDS due to systemic inflammation
RENAL
- Renal failure
- Rhabdomyolysis
- Myoglobin induced ATN
GI
- Severe electrolyte derangement
- LFT derangement
- Acute hepatitis 2 splanchnic blood flow diversion
HAEM
- DIC
- Coagulopathy
IMMUNE
- Diversion of blood flow away from gut
- Bacterial translocation
- Cytokine release
Pharmacological Consequences
A
- ↑drug absoption due to blood diversion
M
- ↓drug metabolism secondary to blood flow diversion and altered enzyme denaturation
E
- ↓drug clearance