Why warm our patients? To maintain a near normal core body temperature to aid patient recovery, normal body temperature = 37 degrees Celsius

Thermoregulation Shivering, NST Vasoconstriction Vasodilation, sweating Interthreshold range 0.2 degree The body’s normal response to temperature

Which patients need warming? The trauma patient Patients' undergoing anaesthesia / surgery Recovery ICU Paediatrics Labour and delivery.

Mild hypothermia Promotes bleeding and increases transfusion requirement. Prolongs drug metabolism. Increases incidence of wound infections. Increases postoperative recovery. Increases the risk of morbid myocardial events. Prolongs hospitalisation. Impaired immune function. Increase cost.

Effects of anaesthesia Anaesthesia causes vasodilation. Warm blood from the core mixes with the colder periphery. Skin – large surface area. Blood circulates, cools and returns to heart. Drop in the core temperature. Redistribution temperature drop (RTD). Anaesthetic agents act on CNS and interfere with hypothalamic control.

Thermoregulation under anaesthesia Shivering, NST Vasoconstriction Vasodilation, sweating Interthreshold range 4 degree Hypothermia 36 degrees Anaesthesia impaired response to temperature:

Why warm fluids? Fluids are generally infused into the body at room temperature, which is over 1ºC below body temperature. The body must then give up its own heat to warm the infused fluids. How do we warm fluids? A medical device used for pre-warming blood and other fluids being administered IV to prevent hypothermia.

Why cool patients? Cooling improves neurological outcome and reduces mortality by: Reduction of cerebral metabolism, oxygen & glucose demand Slowing of the destructive neuroexitatory process Decrease of free radical production Stabilisation of the blood-brain-barrier Reduction of the inflammatory process.