Fever, leucocytosis and C-reactive protein after open-heart surgery and their value in the diagnosis of postoperative infections.

The time course of body temperature (T), white blood cell count (WBC) and serum C-reactive protein (CRP) following uncomplicated open-heart surgery and the value of these three parameters in the diagnosis of postoperative infectious complications were analyzed in 153 patients. Preoperatively, all the patients had a normal T and the WBC level was under 10 X 10(9)/l. The CRP was elevated (over 20 mg/l) in five patients without having an influence on their postoperative courses. Postoperatively, T, WBC and CRP reached their maximum values during the first three days, decreasing gradually thereafter. Great individual variations in this average response to open-heart surgery were seen. Development of minor postoperative infections, mainly wound infection, (in 22 patients) were poorly reflected by these three parameters. However, a temperature exceeding 38 degrees C after the 6th postoperative day suggested presence of infection; less than 5% of patients without an infection had a temperature over this value. A secondary rise in CRP after the third postoperative day occurred in 20 patients and correlated well with postoperative complications; in 14 patients (70%) an infection became apparent, in three instances a probable infection was present, while two patients suffered from non-infectious complications. Only in one case (5%) did the cause for a secondary rise in CRP remain unknown. In major infections, i.e. mediastinitis, a CRP response occurred in all 12 patients, a temperature response in 11 patients (92%) and a WBC response in 10 patients (83%).