Risk factors for neurosurgical site infections after a neurosurgical procedure: a prospective observational study at Hospital Kuala Lumpur

Abstract

Introduction: Surgical site infection (SSI) after craniotomy even though rare, poses a real risk of surgery and represents a substantial burden of disease for both patients and healthcare services in terms of morbidity, mortality and economic cost. The knowledge of risk factor for surgical site infection after craniotomy will allow the authority to implement specific preventive measures to reduce the infection rate. Therefore, the objectives of this study are to determine the incidence and the risk factors of surgical site infection after craniotomy.

Material and methods: This study highlights an observational prospective study on adult patients who has undergone neurosurgical procedures in Hospital Kuala Lumpur (HKL) over a period of 2 years (June 2007 to June 2009). The neurosurgical procedures are craniectomy, craniotomy, cranioplasty and burrhole. A total of 390 cases fulfilled the requirements of inclusion and exclusion criteria were included in the study. Every patient in the study population was prospectively evaluated for development and risk factors for SSI. The follow-up cases were done by direct observation of the wound during their post-operative stay and ideally up to and including day 30 post-operatively, either as in-patients or through post discharge surveillance i.e. follow-up in the clinic 30 days post-operatively. SSIs were defined according to the Center for Disease Control definitions. Incidence was calculated per patient. Univariate Simple Logistic Regression analysis was used to analyse the association of the risk factors and SSI.

Results: A total of 30 post craniotomy surgical site infections (SSI) has been identified among 390 cases included in the study, resulting in an overall infection rate of 7.7%. This included 19 with superficial wound infection (63.3%), 9 with bone flap osteitis (30%) and 2 with organ/space infection (6.7%). Most of SSIs were detected during in patient cases accounting for 20 cases. The mean time between surgery and the onset of infection was 11.8 +/- 21.8 days (median 10 days). The predominantly isolated organism in patients with SSIs were Staphylococcus aureus (11 or 36%) followed by MRSA (4 or 13%), and Acinetobacter spp (3 or 10%). Independent risk factors for SSI were surgeries that were performed by specialist (OR, 76.90 CI, 1.22-39.04.9; P 0.029) and senior medical officer (OR, 8.69 CI, 1.39-54.29.04.9; P 0.021) and surgery that was done for infective causes (OR, 4.44 CI, 1.33-14.81; P 0.015). ASA 2 and clean contaminated wound were independent predictive risk factors for SSI.

Conclusions: Post craniotomy surgical site infection remains an important problem in neurosurgery. Identification of risk factors for SSI should help us to improve patient care, reduce mortality, morbidity and economic burden of health care cost. Post surgical surveillance is important as well to identify the reliable risk factors for SSI.