Internal Medicine

0521779407-09 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 7:54

Hypothermia 801

■Heated IV fluids (40–43◦C) usually not effective, but helps prevent

further cooling

■Heated GI and bladder irrigation not very effective because of limited

surface area; reserved for patients with cardiovascular collapse

■Peritoneal dialysis with heated (40–45◦C) dialysate effective; leave

fluid in place for 15 min then drain off; raises temperature 2◦C/h;

reserved for patients with cardiovascular collapse

■Open and closed thoracic lavage effective, but invasive; requires two

chest tubes; infuse heated (40–42◦C) normal saline into one and

remove through other

■Hemodialysis useful if IV access and equipment available

■Cardiac arrest requires CPR AND rapid rewarming; defibrillation

not reliable at core temperature <32◦C; defibrillate×1 while patient

hypothermic; if unsuccessful, continue CPR and resuscitation until

patient rewarmed, then attempt defibrillation

■Bretylium IV: only antiarrhythmic drug effective for ventricular fib-

rillation in setting of hypothermia

■Consider antibiotics

Side Effects and Complications

■Active external rewarming may cause peripheral vasodilation and

core temperature drop when cold blood from peripheries returns to

central circulation; can cause acidosis and shock

■In severe hypothermia, rigor mortis, lividity, or fixed dilated pupils

are NOT reliable indicators of death; CPR should NOT be withheld;

delay in instituting CPR in field NOT contraindication to full resus-

citation

■Peritoneal dialysis can result in DIC and intraabdominal hemorrhage

and can exacerbate hypokalemia

■Open and closed thoracic lavage can induce ventricular fibrillation

■Cardiopulmonary bypass can cause bleeding, air embolization,

pulmonary edema, and DIC; third spacing common and requires

aggressive volume replacement

Contraindications

■Avoid procainamide, which increases temperature necessary to

defibrillate successfully and may precipitate ventricular fibrillation

■Avoid pulmonary artery catheterization, which may precipitate ven-

tricular fibrillation

■Avoid Ringer’s lactate solution because cold liver metabolizes lactate

poorly