Surgical Site Infections in Clean and CleanContaminated Surgeries at a Tertiary Care Centre: A Longitudinal Study

Abstract

Introduction: Surgical Site Infections (SSIs) are very common and the most frequently studied Hospital-Acquired Infection (HAI) in developing countries. Up to 5% of patients undergoing surgery develop SSIs, which can cause significant morbidity and, in some cases, be fatal. Aim: To determine the prevalence of SSI and compare the factors related to its development between clean and cleancontaminated surgeries. Materials and Methods: This longitudinal study was conducted at a rural tertiary care centre in the Department of General Surgery from May 2020 to April 2021. A total of 1,020 patients who underwent clean and clean-contaminated surgeries were clinically examined, investigated, and provided standard treatment modalities. Dirty and contaminated cases were excluded from the study. Clean and clean-contaminated surgeries were defined according to the guidelines provided by the Centres for Disease Control and Prevention (CDC). Demographic and risk factors, such as sex, age, nature of surgery, wound irrigation, American Society of Anaesthesiologists (ASA) score, smoking, preoperative stay, duration of surgery, hair removal, drains, immunosuppression, Diabetes Mellitus (DM), and Hemoglobin (Hb) levels, were observed and compared between the two groups. The development of SSI was diagnosed based on CDC guidelines. SSI cases were followed up longitudinally in both groups. Continuous variables were analysed using an unpaired t-test, while categorical variables were analysed using a chi-square test. A p-value of <0.05 was considered statistically significant. Results: Out of the 1,020 patients, a total of 93 (9.11%) developed SSI. Among the males (573, 56.17%), 39 (6.8%) developed SSI, while among the females (447, 43.83%), 54 (12.08%) developed SSI. The study found that 24 (3.46%) clean operations and 69 (21.1%) clean-contaminated surgeries developed SSI (p-value<0.0001). There was a significant association between SSI and risk factors such as ASA <2 (p-value<0.01), smoking (p-value< 0.01), DM (p-value< 0.01), Hb <8 gm% (p-value<0.01), shorter preoperative stay (p-value<0.01), prolonged surgery (p-value<0.01), use of drains (p-value<0.01), and immunosuppression (p-value<0.01). The majority of SSIs were caused by Staphylococcus aureus (24 cases, 25.8%), followed by Pseudomonas aeruginosa (18 cases, 19.3%) and Escherichia coli (12 cases, 12.9%). Patients who developed SSI had a mean postoperative stay of 32.35 days, compared to 7.19 days for those who did not develop SSI. Conclusion: The study concluded that SSI was significantly more common in clean-contaminated surgeries compared to clean surgeries. Proper surveillance can help document SSI even after hospital discharge. Prompt identification of organisms can facilitate clinical recovery.