Assessment of postoperative fever

Postoperative fever is defined as a temperature >38°C (100.4°F) on 2 consecutive postoperative days, or >39°C (102.2°F) on any 1 postoperative day.

The reported incidence varies, but it can be expected in about 13% to 14% of patients.[1]Galicier C, Richet H. A prospective study of postoperative fever in a general surgery department. Infect Control. 1985 Dec;6(12):487-90. http://www.ncbi.nlm.nih.gov/pubmed/3852797?tool=bestpractice.com Most cases are self-limiting, requiring only observation. However, it is crucial to recognise a small sub-set of patients who require further investigation and treatment for a serious underlying cause. 

The differential diagnosis is strongly influenced by the time of onset of the fever. The most common cause of fever within the first 48 hours is a pyretic response to surgery, which is self-limiting.[2]O'Mara SK. Management of postoperative fever in adult cardiac surgical patients. Dimens Crit Care Nurs. 2017 May/Jun;36(3):182-92. http://www.ncbi.nlm.nih.gov/pubmed/28375995?tool=bestpractice.com Diagnostic testing is usually unrevealing in this period unless associated symptoms and signs suggest an underlying cause.[3]Schey D, Salom EM, Papadia A, et al. Extensive fever workup produces low yield in determining infectious etiology. Am J Obstet Gynecol. 2005 May;192(5):1729-34. http://www.ncbi.nlm.nih.gov/pubmed/15902186?tool=bestpractice.com [4]Fanning J, Neuhoff RA, Brewer JE, et al. Frequency and yield of postoperative fever evaluation. Infect Dis Obstet Gynecol. 1998;6(6):252-5. http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1784817&blobtype=pdf http://www.ncbi.nlm.nih.gov/pubmed/9972487?tool=bestpractice.com After 48 hours, the incidence of infectious aetiologies increases and a full blood count, chest radiograph, urinalysis with culture, blood cultures, and wound cultures are required as first tests in all patients. Further radiological or laboratory testing is directed towards the suspected aetiology.