environmental emergencies

Question 1

hypothermia: pathophysiology

Answer 1

occurs due to the lowering of core temperature due to conduction, convection or evaporation of heat energy. Thermoreceptors detect low ambient temperature and regional vasoconstriction occurs. this causes the release of TSH and adrenocorticoid hormone from the hypothalamus. this stimulates the thyroid and adrenal glands as well as promoting shivering. eventually the heat preservation mechanisms are overwhelmed and decreased depolarisation of cardiac cells, decreased glomerular filtration and nephron reabsorption occur as well as ECG changes.

Question 2

Hypothermia: sign and symptoms

Answer 2

ECG changes - sinus bradycardia, ST changes, T inversion, QT prolonging.
fatigue
ataxia
diuresis
hypovolemic
altered level of consciousness
hypotension

Question 3

mild hypothermia temp

Answer 3

32-35 degrees C

Question 4

moderate hypothermia temp

Answer 4

28-32 degrees C

Question 5

severe hypothermia temp

Answer 5

<28 degrees C

Question 6

Hypothermia: management

Answer 6

warming blankets (prevention)
BP/HR/temp monitored and controlled
supplemental humidified oxygen
warm IV crystalloid solution if hypovolemic
BE AWARE - drug metabolism decreases in hypothermia
remove wet clothing and cover with warm blankets
extracorporeal blood warming

Question 7

hyperthermia: signs and symptoms

Answer 7

vomiting/nausea
loss of consciousness
core temp over 40 degrees C
alterations in mental status
headache
anxiety
ataxia
dizziness

Question 8

hyperthermia: pathophysiology

Answer 8

cellular destruction occurs rapidly at high core temperatures. thermal stresses trigger systemic inflammatory responses and GI permeability increases increasing the release of toxins into the circulation. These mechanisms lead to profound CNS disturbance.

Question 9

Hyperthermia: management

Answer 9

external cooling
resuscitation
cool first - transfer second

Question 10

frostbite

Answer 10

profound changes in blood flow caused by changes in diameter of blood vessels, in the cold peripheral blood flow is sacrificed. formation of extra and intracellular crystals causes fluid shifts, dehydration and vascular spasticity causes microthrombi.

Question 11

types of hyperthermia

Answer 11

water depletion
sodium depletion