Serum Complement Reactive Protein (CRP) Trends Following Free Flap in Lower Extremity Reconstruction

Abstract

Infectious complication remains a major cause of flap failure. Serum complement reactive protein (CRP) level is a customary measure for early recognition of infections. The aim of this study was to describe the time course of CRP in patients with free flap for trauma and chronic wound problems of the lower extremity. We further evaluated the effect of patient comorbidities influencing serum CRP level.

We retrospectively analyzed the data of all 21 patients who received free flap from June 2009 to March 2012 at the Department of Plastic and Reconstructive Surgery, Ajou University School of Medicine. CRP levels were measured routinely until postoperative 2 weeks. Patient CRP values were expressed as mg/dl and were averaged per day in each group.

Fourteen (66.7%) of the patients reached peak CRP within 3 days. Of the seven patients peaking after day 3, two patients (28.57%) had infective complications(postoperative wound infection and remained wound abscess) and showed a high level and a second peak of CRP about 2 days before symptoms were evident. The other two patients (28.57%) had side effects of antibiotics (drug fever and pseudomembranous colitis) and also displayed a high level of CRP, which subsequently lowered slowly. In these four complication cases, a change in antibiotics guided by a consultant microbiologist was necessary. In all disease-free patients, mean CRP rose from postoperative day 1, peaked at day 2, and decreased significantly from day 4. On the contrary, in the diabetes and hypertension group, the mean CRP rose from postoperative day 2, peaked at day 3, and decreased significantly from day 5. Also, an unexpected and irregular pattern was shown in the diabetes and hypertension group. There was statistical relevance of diabetes and hypertension on CRP trends. However, the non-osteomyelitis group showed more irregular and higher CRP trends than did the osteomyelitis group. There was no statistical significance, perhaps because patients who had complications were all included in the non-osteomyelitis group. Also, all patients of osteomyelitis were early phase and were well-controlled by antibiotics.

Our results confirm that CRP is a very efficient parameter for diagnosis and prognosis of infectious complications after free flap. We also noted the positive correlation between the diabetes, hypertension, and the CRP level in free flap. However, study limitations include the number of patients who met the inclusion criteria. We understand that correlation of serum CRP level to inflammation, complications, and comorbidities can be important and propose that it should be the aim of further studies.