Effects of local and systemic warming on postoperative infections

There is increasing recognition that attention to optimal perfusion and oxygenation, normothermia, and normoglycemia is associated with low postoperative infection rates. The results of several studies on temperature maintenance will be presented.

In a test of the value of systemic warming, patients undergoing major orthopedic, general, or urologic surgery were randomized to standard care with or without systemic warming using a disposable forced warm-air blanket. The addition of perioperative warming using a conductive carbon polymer mattress and overblanket to intraoperative warming was studied in patients undergoing major elective abdominal surgery. In a study of local warming, patients undergoing elective clean-wound surgery were randomized to local warming or non-warming. To determine the contribution of heat to eradication of methicillin-resistant Staphylococcus aureus, patients with stage III-IV pressure sores were randomized to receive or not receive local warming along with standard care.

The intraoperative improvement of cutaneous blood flow and oxygen tension in the systemically warmed group improved tissue viability and reduced the incidence of pressure sores. A statistically significant reduction in morbidity and mortality was found in the patients having the conductive mattress as well as an overblanket. Similar findings are being reported from studies of systemic warming as an adjunct to resuscitation of patients presenting with abdominal pain and elderly patients admitted after a fall or with a suspected fractured femoral neck. Local warming with non-contact radiant heat was as good as systemic warming in preventing surgical site infections.

Attention to keeping patients warm, together with maintenance of optimal perfusion and oxygenation and euglycemia, represents a simple effective guideline. Several methods of warming are available for use during transport and resuscitation and to achieve perioperative normothermia.