Hyperthermia and Hypothermia Flashcards
What is the definition hypothermia?
core body temperature <35°C (<95°F)
What are RF for hypothermia?
- General anaesthetic use
- Extremes of age
- Immobility
- Substance misuse
- Impaired cognition
- Hypothyroidism
- Stroke
- Parkinson’s disease
- Homelessness
- Gram-ve septicaemia
What are two ways you can get hyperthermia?
- Passive severe environmental heat esp at risk patients during heat wave
- Strenuous physical exercise in heat
What are RF for hyperthermia?
- Extremities of age
- Poor physical condition
- Pre-existing dehydration
- Obesity
- Environmental factors
- Drugs e.g. amphetamines
- Alcohol misuse
What are symptoms and signs of hypothermia?
- Cold exposure and body temp <35 degrees
- Cognitive impairment
- Shivering
- Frostbite
What are symptoms and signs of hyperthermia?
- Central Nervous System dysfunction
- Hyperthermia (>40degrees)
- Anhidrosis
- Intense thirst
- Weakness
- Anxiety
What is differential diagnosis for hypothermia?
- Sepsis
2. Hypothyroidism
What is differential diagnosis for hyperthermia?
- Delirium
- Meningitis
- DKA
- Hyperthyroidism
- Serotonin syndrome
What investigations do you do for hypothermia?
- core temp measurement
- 12 lead ECG
- Blood glucose
- Blood gas
- Serum urea, electrolytes and creatinine
- FBC
- Clotting screen
- CXR
Why is a 12 lead ECG used in hypothermia?
continuous monitoring for arrythmias that could be fatal e.g. could have sinus bradycardia, AF
What may a blood gas show in hypothermia?
respiratory alkalosis or metabolic acidosis or both
What would respiratory acidosis be suggested by?
pH <7.35 and PCO2 >40 mmHg
What would metabolic acidosis be suggested by?
pH <7.35, bicarbonate ≤24 mEq/L, and a normal PCO2, although it may be low with compensation
What would PaO2 being low suggest?
may be low with severe hypothermia, and/or if there are pulmonary infiltrates or oedema
What would serum urea, electrolytes and creatinine be like in hypothermia?
- hyperkalemia
2. hypokalaemia
What would the clotting screen show in hypothermia?
elevated PT and PTT
What would the CXR suggest in hypothermia?
may show pulmonary infiltrates, oedema
What investigations would you do for hyperthermia?
- Rectal Temp
- FBC
- LFTs
- RFTs
- Electrolytes
- ABG
- CK
- Clotting profile
- Urinalysis
- Glucose
- ECG
What would FBC show in hyperthermia?
- Neutrophilia
- Anaemia
- Thrombocytopenia
What would the RFTs show in hyperthermia?
elevated creatine and blood urea
What would electrolytes show in hyperthermia?
hypo or hyperkalaemia
What would ABG show in hyperthermia?
- elevated lactate
- metabolic acidosis
- respiratory alkalosis
What would the CK show in hyperthermia?
elevated esp w/ rhambodylosis
What would clotting profile show in hyperthermia?
may show elevated prothrombin time, activated PTT, INR; hypofibrinogenaemia
What may the urinalaysis show in hyperthermia?
myoglobinuria and/or haemoglobinuria
What would the ECG show in hyperthermia?
- arrhythmias
- conduction abnormalities
- non-specific ST/T wave changes
How would you manage hypothermia?
- Stop cooling
- CPR
- Humidified oxygen
- Warmed IV fluids
- Haemofiltration
How would you manage hyperthermia?
- Stabilisation
- Active cooling
- Supportive care and observation
What are possible complications of hypothermia?
- Hypoglycaemia
- Hyperkalaemia
- Cardiac arrythmias
- GI disorders
- Bleeding diathesis
What are possible complications of hyperthermia?
- ARDS
- Shock
- AKI
- Acute liver failure
- Rhabdomylosis
- DIC
- CVD
- Mutli-system organ failure
What is prognosis of hypothermia like?
- core temperature <26°C (<78.8°F) do not survive
- triad of coagulopathy, acidosis, and hypothermia is also associated with increased mortality.
- If >70to and temp<32 mortality 50%
What is the prognosis of hyperthermia like?
mortality from heat stroke in older adults can exceed 50%
