PCL 1- Pathophysiology of Hypothermia

Hey G's!

So i've done my bit, if u have any doubts, i shall try my best to clear them on friday! :)

cheers! <3>

IMMUNE

Possible decreased:

-chemotaxis

-phagocytosis

--antibody production

-oxidative killing

HAEMOPOIETIC

- Vasoconstriction, which occurs with hypothermia, may mask hypovolemia, which then manifests as sudden shock or cardiac arrest during re-warming (re-warming collapse) when peripheral vasculature dilates.

-Reflex Vasconstriction in visceral muscles; blood is shunted to the essential organs, (heart, brain).

-Causes marrow suppression and progressive marrow failure; decreased red cell deformability.

-Increased blood viscocity, fribrinogen and haematocrit; these may underlie disorders in the function of many other organs.

- Changes in vascular permeability leads to haemoconcentration.

-Coagulopathy can develop; Thrombocytopaenia can also occur.

- Rightward oxyhemoglobin shift.

CARDIAC

- Hypothermia results in decreased depolarization of cardiac pacemaker cells, causing bradycardia.

- Decrease in heart rate results in decrease of blood pressure and cardiac output.

- Atrial and ventricular arrhythmias could be a result of Hypothermia as well.

- At temperatures less than about 24 °C, there is a high risk of asystole.

RESPIRATORY

- Mild hypothermia, there is an initial tachypnoea; followed by reduction in minute volume and reduced oxygen consumption.

- Moderate levels of hypothermia, protective airway reflexes are reduced.

- Reductions in oxygen consumption and carbon dioxide production occur.

- Severe hypothermia, progressive hypoventilation and apnoea develop, and (more rarely) pulmonary oedema.

- FALSELY increased partial pressure of Oxygen.

http://emedicine.medscape.com/article/770542-overview

http://qjmed.oxfordjournals.org/cgi/content/full/95/12/775

http://www.adhb.govt.nz/trauma/presentations/Forums/injury_2002/alexn/tsld009.htm