Angel L Fernández1,2, Belén Adrio2, José M Martínez Cereijo2, Maria Amparo Martínez Monzonis3, Mohammad M El-Diasty1, Julian Alvarez Escudero1,4. 1. Department of Surgery and Medico-Surgical Specialties, University of Santiago de Compostela, Santiago de Compostela, Spain. 2. Service of Cardiac Surgery, University Hospital, Santiago de Compostela, Spain. 3. Service of Cardiology, University Hospital, Santiago de Compostela, Spain. 4. Service of Anaesthesiology and Postoperative Critical Care, University Hospital, Santiago de Compostela, Spain.
Abstract
OBJECTIVES: Nosocomial infection caused by Serratia marcescens after cardiac surgery is rare but causes high rates of morbidity and mortality. Knowledge about postoperative mediastinitis due to S. marcescens is limited. The purpose of this work was to study the clinical presentation, management and outcome of an outbreak of postoperative sternal infection due to S. marcescens. METHODS: During a 7-week period, a total of 54 patients underwent open heart procedures in our hospital. A postoperative wound infection caused by S. marcescens was diagnosed in 10 patients. We performed a clinical study to investigate patient characteristics and outcomes as well as the possible source of the infection. RESULTS: The mean age of the infected patients was 74.5 ± 10 years. Mediastinitis was present in 6 cases, superficial wound infection in 3 and isolated bacteraemia in 1. Purulent exudate through the sternal incision was observed in all infected cases except in 1 patient, who presented only with bacteraemia. Serratia marcescens was isolated from the samples taken from all infected wounds. The mean time elapsed between the operation and the isolation S. marcescens was 5.9 ± 2.4 days. Response to treatment was favourable in all cases except 1, who died. Contamination of the aqueous chlorhexidine solution used to prepare the patients' skin with S. marcescens was reported. Microbiological studies demonstrated that S. marcescens strains isolated from patients and from the aqueous chlorhexidine solution belonged to the same clone. CONCLUSIONS: The use of an aqueous chlorhexidine solution contaminated with S. marcescens caused an outbreak of postoperative sternal wound infections. The time elapsed between wound contamination and signs of infection was brief, but the systemic inflammatory response and tissue necrosis were limited. Alcohol-based solutions are recommended for the prevention of surgical site infections.
OBJECTIVES:Nosocomial infection caused by Serratia marcescens after cardiac surgery is rare but causes high rates of morbidity and mortality. Knowledge about postoperative mediastinitis due to S. marcescens is limited. The purpose of this work was to study the clinical presentation, management and outcome of an outbreak of postoperative sternal infection due to S. marcescens. METHODS: During a 7-week period, a total of 54 patients underwent open heart procedures in our hospital. A postoperative wound infection caused by S. marcescens was diagnosed in 10 patients. We performed a clinical study to investigate patient characteristics and outcomes as well as the possible source of the infection. RESULTS: The mean age of the infectedpatients was 74.5 ± 10 years. Mediastinitis was present in 6 cases, superficial wound infection in 3 and isolated bacteraemia in 1. Purulent exudate through the sternal incision was observed in all infected cases except in 1 patient, who presented only with bacteraemia. Serratia marcescens was isolated from the samples taken from all infected wounds. The mean time elapsed between the operation and the isolation S. marcescens was 5.9 ± 2.4 days. Response to treatment was favourable in all cases except 1, who died. Contamination of the aqueous chlorhexidine solution used to prepare the patients' skin with S. marcescens was reported. Microbiological studies demonstrated that S. marcescens strains isolated from patients and from the aqueous chlorhexidine solution belonged to the same clone. CONCLUSIONS: The use of an aqueous chlorhexidine solution contaminated with S. marcescens caused an outbreak of postoperative sternal wound infections. The time elapsed between wound contamination and signs of infection was brief, but the systemic inflammatory response and tissue necrosis were limited. Alcohol-based solutions are recommended for the prevention of surgical site infections.