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Stop the Drop: Preventing Perioperative Hypothermia

Blue Mountains District ANZAC Memorial Hospital
Project Added:
28 October 2016
Last updated:
22 April 2021

Stop the Drop: Preventing Perioperative Hypothermia


The steps in the perioperative pathway were reviewed and a number of interventions trialled to maintain the temperature of patients prior to, during and following surgery.


To reduce the incidence of hypothermia in elective theatre patients at Blue Mountains District ANZAC Memorial Hospital to below 5%, by July 2016.


Reducing hypothermia can reduce perioperative blood loss, wound infections, cardiac complications and pressure sores. Post-operative patients are likely to be more comfortable, less anxious and more satisfied with their care. Recovery times may be reduced and theatre efficiencies may be improved.


An audit conducted in November 2015 revealed a high incidence of inadvertent perioperative hypothermia ( IPH ) at Blue Mountains District ANZAC Memorial Hospital. IPH is defined as a temperature below 36 degrees Celsius on arrival to the post-operative recovery area. While national standards suggest IPH rates below 1% to be achievable1, the Hospital had rates of 32% for operative cases and 40% for endoscopy cases.

The high rate of IPH had persisted despite strategies implemented in July 2015 to reduce them. Previous strategies included:

  • ensuring patient thermometers were accurate and regularly calibrated
  • improving theatre list scheduling, with realistic operation times and staggered patient arrival times
  • improving the information provided to patients before their operation, including the importance of staying warm
  • educating staff on the importance of recording temperatures and avoiding hypothermia
  • issuing cotton blankets in the Day Unit to waiting patients
  • maintaining theatre room temperatures at 18-19 degrees Celsius.

Despite these strategies, there continued to be high levels of IPH , low levels of patient satisfaction and delays to recovery following surgery. A new approach was required to minimise the rate of IPH in the future.


  • An evaluation of the perioperative pathway was undertaken, to identify areas that would benefit from interventions.
  • Theatre wall thermometers were installed, to help clinicians accurately monitor room temperatures during surgery.
  • Theatre temperatures were increased to 20 degrees Celsius and warm air blankets were used in operative cases, with cotton blankets used for endoscopy cases.
  • Patients were brought into the anaesthetic bay earlier than usual (roughly 20 minutes instead of 40 minutes) as the anaesthetic bay was cooler than the Day Unit. It was determined that keeping patients in the Day Unit for longer periods of time should help them stay warmer.
  • Inditherm® warming mattresses on theatre tables were trialled in operative cases, while EasyWarm® disposable self-heating warming blankets were trialled for endoscopy cases.
  • Self-warming blankets were provided to patients in the day unit and stayed with them during their time in the anaesthetic bay, theatre and recovery.

Project status

Implementation - the initiative is currently being implemented, piloted or tested.

Implementation sites

Blue Mountains District ANZAC Memorial Hospital, NBMLHD


Clinical Leadership Program


  • An evaluation was conducted in July 2016, which involved measuring the temperature of each patient as they arrived in recovery. Those who had a temperature below 36 degrees Celsius were noted as having IPH .
  • The IPH rate in operative cases reduced from 32% in November 2015 to 17% in July 2016.
  • The IPH rate in endoscopy cases reduced from 40% in November 2015 to 22% in July 2016.
  • The final evaluation showed that early interventions had surprisingly little effect on IPH . The most effective interventions were active warming devices that generated heat, rather than passive interventions that reduced heat loss.
  • The only two interventions that reduced IPH rates were warming mattress on theatre tables for operative patients and self-warming blankets for endoscopy patients.
  • A cost analysis showed that implementing these interventions in clinical practice would be cost-neutral.
  • While the stretch goal of 5% was not achieved, the rate of IPH was significantly reduced in both groups.

Lessons learnt

  • Having motivated and influential staff on the project team is vital to implementing change.
  • Data collection sheets should be as straightforward as possible.
  • Changes which are perceived to increase workload are difficult to successfully implement.
  • The project team failed to institute and adequately trial the effectiveness of intravenous fluid warming, largely because the fluid warming device available was difficult and time-consuming to set up.


  1. Australian Council on Healthcare Standards ( ACHS ). Australasian Clinical Indicator Report: 2007–2014: 16th Edition. Sydney, Australia: ACHS ; 2015.

Further reading


Dr David Campbell
Senior Specialist Anaesthetist and Head of Department
Blue Mountains District ANZAC Memorial and Springwood Hospitals
Nepean Blue Moutains Local Health District
Phone: 02 4784 6540

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