Hypothermia Flashcards
What is the definition of hypothermia?
unintentional reduction of core body temperature below the normal physiological limits
What is the initial physiological response to hypothermia?
- thermoreceptors in the skin and subcutaneous tissues sense the low temperature and cause a regional vasoconstriction
- therefore hypothalamus stimulates the release of TSH and ACTH
- stimulates heat production by promoting shivering
What are 2 hormones released by the hypothalamus in response to hypothermia?
TSGH
ACTH
What is the definition of mild hypothermia?
32-35 oC
What is the definition of moderate hypothermia?
28-32oC
Which demographic is particularly susceptible to hypothermia?
elderly, most commonly during winter
What are 4 causes of hypothermia?
- Exposure to cold in the environment
- Inadequate insulation in the operating room (surgery)
- Cardiopulmonary bypass
- Newborn babies
What are 6 risk factors for hypothermia?
- General anaesthesia
- Substance abuse
- Hypothyroidism
- Impaired mental status
- Homelessness
- Extremes of age
What are 6 signs of hypothermia?
- Shivering
- Cold and pale skin
- Slurred speech
- Tachypnoea, tachycardia and hypertension (if mild)
- Respiratory depression, bradycardia and hypotension (if moderate)
- Confusion/ impaired mental state
What will vital signs be like in mild vs moderate hypothermia?
- mild: tachypnoea, tachycadia, hypertension
- moderate: respiratory depression, bradycardia, hypotension
How might a baby with hypothermia present?
may look healthy, but by limp, unusually quiet and refuse to feed
What is done in newborns to prevent hypothermia?
hat and clothing/blankets are applied soon after birth
What are 7 investigations that may be performed in hypothermia?
- Temperature
- 12 lead ECG
- FBC, U+Es
- Blood glucose
- ABG
- Coagulation factors
- CXR
What are 2 ways that core temperature can be measured to assess hypothermia?
- Low-reading rectal thermometer
- Thermistor probe
When should a patient’s temperature be measured in suspected hypothermia and why?
should be tracked over time, to check for improvement