Andrea C Issler-Fisher1, Richard M Fakin 2, Oliver M Fisher 3, Genevieve McKew4, Riccardo Gazzola2, Ann-Kathrin Rauch2, Thomas Gottlieb4, Peter Haertsch1, Merlin Guggenheim2, Pietro Giovanoli2, Peter K M Maitz5

1 Burns Unit, Concord Repatriation General Hospital, Hospital Rd, Concord NSW 2139, Australia;
andrea.isslerfisher@gmail.com
2 Division of Plastic & Hand Surgery, University Hospital Zurich, Raemistrasse 71, 8006 Zuerich, Switzerland;
Richard.Fakin@usz.ch
3 St. Vincent’s Centre for Applied Medical Research, 405 Liverpool St, Sydney NSW 2011, Australia; ofisher@gmx.ch
4 Department of Microbiology & Infectious Diseases, Concord Repatriation General Hospital, Hospital Rd,
Concord NSW 2139, Australia
5 Burns Unit, Concord Repatriation General Hospital, Hospital Rd, Concord NSW 2139, Australia;
peter.maitz@sydney.edu.au

Background: The incidence and frequency of microbiological organisms are known to vary across different models of intensive care units. To date, no study has attempted to describe the different findings in burn patients treated in an open, general intensive care unit (GICU) versus a dedicated burns intensive care unit (BICU).
Aim: To characterize and compare the microbiological flora and antibiotic resistance patterns encountered in two different models of burn intensive care and to determine the effect of specific microbiological types on length of ICU and overall stay.
Methods: A retrospective case-control study of 209 burn patients treated in two specialized, Western burn referral centres between September 2009 and March 2014.
Results: 9710 culture results were analyzed, of which 2590 (26.7%) yielded positive results. Gram-positive cultures were more frequently found in the GICU, whereas Gram-negative and yeast cultures were more prevalent in the BICU. The most frequently encountered organisms in both units were similar and included Staphylococcus aureus, Pseudomonas aeruginosa, coagulase-negative staphylococci (CoNS) and Candida albicans. Significantly more resistant bacteria were detected in the BICU. Testing positive across all types of microbiological isolates, as well as for both Gram-positive and -negative bacteria significantly prolonged patient length of stay. This effect was even more pronounced if the organisms were resistant to antimicrobial therapy.
Conclusion: There are notable differences in the microbiological isolates and antibiotic resistance patterns between burn patients treated in a GICU compared to a BICU. In both units, burn patients with resistant microbiological organisms have significantly longer length of stay.
Key Words
burns, microbiology, intensive care unit, open, closed