POSTOPERATIVE HYPOCHOLESTEROLAEMIA AND HYPOALBUMINAEMIA AS PREDICTORS OF SURGICAL SITE INFECTIONS IN ELECTIVE GENERAL SURGICAL PROCEDURES: A PROSPECTIVE OBSERVATIONAL STUDY

Abstract

Background: Surgical site infection (SSI) is a leading cause of postoperative morbidity in elective general surgery. Postoperative hypocholesterolaemia and hypoalbuminaemia are recognised metabolic consequences of the cytokine-mediated acute-phase response to surgical trauma. Their utility as serial predictors of SSI in a heterogeneous elective surgical population has not been rigorously evaluated in Indian tertiary care settings.

Objectives: To determine whether serial postoperative serum total cholesterol and albumin levels predict the development of SSI in patients undergoing elective general surgical procedures, and to identify clinically actionable threshold values.

Methods: A prospective observational study was conducted over 18 months at SRM Medical College Hospital and Research Centre, Tamil Nadu, India. One hundred and forty-eight adults (age 18–65 years, ASA Grade I–II) with normal preoperative albumin (≥3.5 g/dL) undergoing elective general surgery were enrolled consecutively. Serum total cholesterol and albumin were measured at 24 hours, 7 days, 14 days, and 28 days postoperatively. Wound status was assessed serially using the Southampton Wound Grading System, with SSI defined as Southampton Grade ≥2 corroborated by CDC/NHSN criteria. Chi-square tests, independent t-tests, and Pearson correlation were applied; p < 0.05 was considered significant.

Results: SSI occurred in 35 of 148 patients (23.6%); 68.6% were superficial and 31.4% deep incisional infections. Postoperative total cholesterol declined from 191.78 ± 23.58 mg/dL preoperatively to 142.72 ± 22.23 mg/dL at 24 hours (25.6% reduction), recovering to 181.03 ± 27.63 mg/dL by day 28. Albumin fell from 4.14 ± 0.33 g/dL to 3.47 ± 0.36 g/dL at 24 hours, recovering to 3.98 ± 0.38 g/dL at day 28. Cholesterol below 150 mg/dL at 24 hours was associated with SSI in 36.5% versus 6.3% above threshold (p < 0.0001). Albumin below 3.0 g/dL at 24 hours was associated with SSI in 63.2% versus 9.2% with normal albumin (p < 0.0001). These associations remained significant at all four time points. SSI-positive patients had significantly lower mean cholesterol and albumin at every time point (all p < 0.0001) and longer hospitalisation (15.86 ± 3.54 vs. 6.36 ± 1.90 days; p < 0.0001). Albumin at day 7 yielded the strongest negative correlation with hospital stay (r = −0.5230; p < 0.0001). Wound classification was the only conventional operative parameter significantly associated with SSI (p = 0.014).

Conclusions: Postoperative total cholesterol below 150 mg/dL and albumin below 3.0 g/dL at 24 hours are significant, inexpensive, and universally available early predictors of SSI in elective general surgery. Concurrent derangement of both markers identifies the highest-risk patients. Serial biochemical wound surveillance incorporating these two readily available markers is recommended for South Asian tertiary surgical units.