Obesity and risk of catheter-related infections in the ICU. A post hoc analysis of four large randomized controlled trials.

Abstract

Obesity increases the risk of nosocomial infection, but data regarding the role of body mass index (BMI) in catheter related infections are scarce. We used the data gathered from four randomized, controlled trials (RCTs) to investigate the association between body mass index (BMI) and intravascular catheter infections in critically ill obese patients. Adult obese patients who required short-term central venous, arterial or dialysis catheter insertion in the intensive care unit (ICU) were analyzed. The association between BMI and major catheter-related infection (MCRI), catheter-related bloodstream infection (CRBSI) and catheter tip colonization was estimated using univariate and multivariate marginal Cox models. Exploratory analysis using dressing disruptions was added. A total of 2282 obese patients and 4275 catheters from 32 centers were included in this post-hoc analysis. Overall, 66 (1.5%) MCRI, 43 (1%) CRBSI and 399 (9.3%) catheter colonizations were identified. The hazard ratio (HR) for MCRI, CRBSI and colonization increased with BMI. After adjustment for well-known infection risk factors, the BMI ≥ 40 group had an increased risk for MCRI (HR 1.88, 95% CI 1.13-3.12, p = 0.015), CRBSI (HR 2.19, 95% CI 1.19-4.04, p = 0.012) and colonization (HR 1.44, 95% CI 1.12-1.84, p = 0.0038) compared to the BMI < 40 group. The mean dressing disruption per catheter was increased in the BMI ≥ 40 group (2.03 versus 1.68 in the BMI < 40 group, p = 0.05). Using the largest dataset ever collected from large multicentric RCTs, we showed that patients with BMI ≥ 40 had an increased risk for intravascular catheter infections. Targeted prevention measures should focus on this population with a particular attention to catheter care and dressing disruption.