operating theatre hypothermia

Last reviewed 01/2018

Patient hypothermia is a continuous concern during surgery under a general anaesthetic. It is caused by:

  • the anaesthetic:
    • unconscious patient, therefore, lack of behavioural measures to maintain warmth
    • cutaneous vasodilatation with increased heat loss due to indirect hypothalamic depression of agent and direct peripheral action
    • lack of shivering due to central depression
    • cold anaesthetic gases respired
    • cold fluids given intravenously

  • surgery:
    • patient usually has relatively large proportion of body surface area exposed
    • immobile, no possibility of skeletal muscle activation
    • low ambient theatre temperature encourages radiation and conduction losses
    • theatre air systems e.g. laminar flow, increase heat loss by convection
    • cold surgical instruments applied to skin
    • haemorrhage of relatively warm blood at core temperature

Prevention is the aim. Most measures are simple e.g. insulating all but surgical field, warming blood.