Bacterial colonization of pressure ulcers: assessment of risk for bloodstream infection and impact on patient outcomes

Abstract

Background: Pressure ulcers (PUs) represent a major problem for hospitalized patients, health professionals and society.

Aim: To evaluate the impact of in-hospital PUs as a reservoir of multidrug-resistant organisms (MDROs), risk factor for bacteraemia and predictor of poor prognosis.

Methods: A prospective cohort study of patients with stage II or greater PUs hospitalized in a tertiary acute care university teaching hospital for more than 48 h was performed to evaluate colonization/infection by potential and/or multi-resistant hospital pathogens from April to December 2005 and from August 2009 to April 2010.

Findings: A total of 145 patients with stage II or greater PUs were included. Of these, 76.5% (111/145) had PUs colonized and/or infected with either S. aureus (20.7%), Gram-negative bacilli (32.5%), or both (46.8%) and most were MDROs (64.8%). Bacteraemia was detected in 50.5% (56/111) of the patients. The ulcers were considered to be the probable source of bacteraemia in 53.6% (30/56) of the episodes. Prior administration of antibiotics (P = 0.04) and infected wound (P < 0.001) were the variables independently associated with bloodstream infection as well as associated with a higher 30-day mortality rate; risk factors for the latter included hospitalization in ICU (P = 0.03) and mechanical ventilation use (P = 0.05).

Conclusions: Our results suggest that besides being a major reservoir of MDROs, patients with PUs constitute a high-risk population for bacteraemia with a poor outcome. Broad-spectrum antibiotics and infected wound were independent factors predisposing patients to both bacteraemia and death.