Differences in Antimicrobial Use and Susceptibilities for Gram Negative Organisms between Intensive Care Units and the Emergency Department: Implications for Antimicrobial Stewardship
Methods: Retrospective review of the microbiology surveillance system (VigilanzÒ) comparing antimicrobial susceptibilities patterns of bacterial isolates between hospital adult intensive care units (ICUs) and the emergency department (ED), at Jackson Memorial Hospital (1550 beds, Miami, FL) from June 2012 to June 2013. Only the first positive isolate per patient was included. Antibiograms were categorized by patient location in Surgical ICU (SICU), Medical ICU (MICU), and ED. Antimicrobial use was measured in days of therapy (DOT)/1000 patient days. Proportions of bacteria susceptibilities to specific antibiotics were compared between patient locations using chi-square test of Fisher’s exact test where appropriate. Any post-hoc testings were performed using Bonferroni’s adjustment for family-wise error rate.
Results: 4,980 bacterial isolates were analyzed. 1289 (26%) ED, 536(11%) MICU, 349(7%) TICU, 318 (6%) SICU, 302(6%) NSICU. Pseudomonas aeruginosa susceptibilities to cefepime differed between ED 89%, MICU 75%, SICU 66% (p= <0.0001), ED vs SICU (p=0.0164) was significant. P. aeruginosa isolates were more susceptible to meropenem in the ED than MICU and SICU (93% vs 72% p=0.0078 and 93% vs. 53% p<0.0001 respectively). Klebsiella pneumoniae susceptibilities to cefepime differed between ED 91%, MICU 75% and SICU 85% (p= 0.0197), ED vs MICU (p=0.0174) was significant. Antimicrobial use in DOTs differed between units: vancomycin was the most used antibiotic in all units. Meropenem used differed between units, ED used less 16.53gr/ 1000 patient days. MICU used more cefepime than other units.
Conclusion: There are differences in antimicrobial susceptibilities between units. GN organisms were more susceptible to cefepime and meropenem in the ED than in specific unit (MICU, SICU). We also observed that cefepime was used more in the MICU. Further analysis are needed to determine if antimicrobial use correlates with trends in antimicrobial resistance for each unit.
L. Ka-Ming, None