The objective of this study is to determine the combined impact of a scheduled antibiotic rotation for empiric coverage of gram negative nosocomial pneumonia followed by antibiotic de-escalation based upon culture results in critically injured trauma patients. We hypothesize that gram-negative resistance can be reduced by these interventions.
Sputum cultures in a dedicated TICU at a Level I Trauma Center for six months prior to beginning a scheduled rotation of empiric combination antibiotics served as a control period. An antibiotic rotation was initiated from 4/98 to 12/2000 in patients who met modified criteria of the 1995 American Thoracic Society Consensus Statement. Three antibiotic combinations were chosen based upon control period antibiogram: Amikacin/Imipenem, Amikacin/Zosyn, Amikacin/Levaquin. Antibiotic coverage was de-escalated based upon patient-specific culture results. A resistance index (RI) was calculated for each bacterial isolate. Length of stay (LOS), ICU days, revised trauma score (RTS), injury severity score (ISS) were analyzed using ANOVA and Bonferroni post-hoc test. Mortality was analyzed using a Fisher’s test. Results were significant if p<0.05.
Gram-negative RI decreased significantly from 6.28 in the control period to 4.79 in the first six months and to a low of 3.89 in the fourth 6 month period. There were no significant differences between the groups RTS, ISS, length of stay, ICU days, or mortality rates.CONCLUSIONS: Rotation of empiric antibiotics combined with de-escalation reduces antibiotic resistance in gram negative pneumonia. Decreased resistance is maintained through multiple cycling periods.
Nosocomial pneumonia carries an attributable mortality of 14–38%, with an annual cost of $5–10 billion annually. Interventions that can decrease resistance may be correlated with decreased mortality, resource utilization and may prevent the emergence of increasingly resistant bacterial organisms.
L.K. Browder, None.