title: A 9-Year retrospective review of antibiotic cycling in a surgical intensive care unit.
abstract: BACKGROUND
  Six years after initiating a monthly antibiotic cycling protocol in the surgical intensive care unit (SICU), we retrospectively reviewed antibiogram-derived sensitivities of predominant gram-negative pathogens before and after antibiotic cycling. We also examined susceptibility patterns in the medical intensive care unit (MICU) where antibiotic cycling is not practiced.
  
  
  METHODS
  Antibiotic cycling protocol was implemented in the SICU starting in 2003, with monthly rotation of piperacillin/tazobactam, imipenem/cilastin, and ceftazidime. SICU antibiogram data from positive clinical cultures for years 2000 and 2002 were included in the pre-cycling period, and those from 2004 to 2009 in the cycling period.
  
  
  RESULTS
  Profiles of SICU pseudomonal isolates before (n = 116) and after (n = 205) implementing antibiotic cycling showed statistically significant improvements in susceptibility to ceftazidime (66% versus 81%; P = 0.003) and piperacillin/tazobactam (75% versus 85%; P = 0.021), while susceptibility to imipenem remained unaltered (70% in each case; P = 0.989). Susceptibility of E. coli isolates to piperacillin/tazobactam improved significantly (46% versus 83%; P < 0.0005), trend analysis showing this improvement to persist over the study period (P = 0.025). Similar findings were not observed in the MICU. Review of 2004-2009 antibiotic prescription practices showed monthly heterogeneity in the SICU, and a 2-fold higher prescribing of piperacillin/tazobactam in the MICU (P < 0.0001).
  
  
  CONCLUSIONS
  Six years into antibiotic cycling, we found either steady or improved susceptibilities of clinically relevant gram-negative organisms in the SICU. How much of this effect is from cycling is unknown, but the antibiotic heterogeneity provided by this practice justifies its ongoing use.
authors.affiliation: Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA.
authors.forename: Shiva
authors.initials: S
authors.lastname: Sarraf-Yazdi
authors.forename: Michelle
authors.initials: M
authors.lastname: Sharpe
authors.forename: Kyla M
authors.initials: KM
authors.lastname: Bennett
authors.forename: Tim L
authors.initials: TL
authors.lastname: Dotson
authors.forename: Deverick J
authors.initials: DJ
authors.lastname: Anderson
authors.forename: Steven N
authors.initials: SN
authors.lastname: Vaslef
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002442:Ceftazidime / Q000008:administration & dosage; D015377:Cilastatin / Q000008:administration & dosage; D000077728:Cilastatin, Imipenem Drug Combination; D003422:Critical Care / Q000379:methods*; D003428:Cross Infection / Q000188:drug therapy / Q000517:prevention & control; D004338:Drug Combinations; D024881:Drug Resistance, Bacterial; D016972:Enterobacter cloacae / Q000187:drug effects; D004756:Enterobacteriaceae Infections / Q000188:drug therapy / Q000517:prevention & control; D004926:Escherichia coli / Q000187:drug effects; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000517:prevention & control; D006801:Humans; D015378:Imipenem / Q000008:administration & dosage; D017053:Infection Control / Q000379:methods*; D007710:Klebsiella Infections / Q000188:drug therapy / Q000517:prevention & control; D007711:Klebsiella pneumoniae / Q000187:drug effects; D010397:Penicillanic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives; D010878:Piperacillin / Q000008:administration & dosage; D000077725:Piperacillin, Tazobactam Drug Combination; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000517:prevention & control; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012189:Retrospective Studies; D013530:Surgical Wound Infection / Q000188:drug therapy* / Q000517:prevention & control*
chemical_list: D000900:Anti-Bacterial Agents; D004338:Drug Combinations; D015377:Cilastatin; D000077725:Piperacillin, Tazobactam Drug Combination; D015378:Imipenem; D010397:Penicillanic Acid; D000077728:Cilastatin, Imipenem Drug Combination; D002442:Ceftazidime; D010878:Piperacillin