Hypothermia Flashcards
1
Q
What is the main mechanism of hypothermia related pathology?
A
Impairment of temperature sensitive Na+-K+ pump in various organ systems.
2
Q
Explain pathophysiology and features of hypothermia’s effect on the cardiac system (2)
A
1) Bradycardia – Na influx into cell is passive diffusion, but K+ efflux requires active exchange. This becomes prolonged, resulting in a longer single cardiac AP and this bradycardia.
2) Arrhythmias/Arrest – in addition to prolonged repolarization, the resting potential (normally -90mV) raises due to inadequate K+ exchange, approaching the TP (threshold potential for excitation, -70mV), leaving the cell excitable and prone to aberrant conduction.
