Tamar Gottesman1, Orit Yossepowitch1, Evgenia Lerner2, Orna Schwartz-Harari2, Arie Soroksky3, Daniel Yekutieli4, Michael Dan5. 1. Infectious Diseases Unit, E. Wolfson Hospital, Holon 58100, Israel. 2. Microbiology Laboratory, E. Wolfson Hospital, Holon 58100, Israel. 3. Intensive Care Unit, E. Wolfson Hospital, Holon 58100, Israel. 4. Department of Statistics and Operations Research, Tel Aviv University, Tel Aviv, Israel. 5. Infectious Diseases Unit, E. Wolfson Hospital, Holon 58100, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel. Electronic address: midan@post.tau.ac.il.
Abstract
OBJECTIVE: To evaluate the Gram stain of deep tracheal aspirate as a tool to direct empiric antibiotic therapy, and more specifically as a tool to exclude the need for empiric antibiotic coverage against Staphylococcus aureus in ventilator-associated pneumonia (VAP). DESIGN: A prospective, single-center, observational, cohort study. SETTING: All wards at a community hospital. PATIENTS: Adult patients requiring mechanical ventilation, identified as having VAP in a 54-month prospective surveillance database. INTERVENTIONS: Sampling of lower airway secretions by deep endotracheal aspiration was taken from each patient who developed VAP. Samples were sent immediately for Gram stain and qualitative bacterial cultures. Demographic and relevant clinical data were collected; Gram stain, culture, and antibiotic susceptibility results were documented; and outcome was followed prospectively. MEASUREMENTS AND MAIN RESULTS: The analysis included 114 consecutive patients with 115 episodes of VAP from June 2007 to January 2012. Sensitivity of Gram stain compared with culture was 90.47% for gram-positive cocci, 69.6% for gram-negative rods, and 50% for sterile cultures. Specificity was 82.5%, 77.8%, and 79%, respectively. Negative predictive value was high for gram-positive cocci (97%) and sterile cultures (96%) but low for gram-negative rods (20%). Acinetobacter baumanii (45%) and Pseudomonas aeruginosa (38 %) were the prevailing isolates. S aureus was found in 18.3% of the patients. Most isolates were multiresistant. CONCLUSIONS: Absence of gram-positive bacteria on Gram stain had a high negative predictive value. These data can be used to narrow the initial empiric antibiotic regimen and to avoid unnecessary exposure of patients to vancomycin and other antistaphyloccocal agents.
OBJECTIVE: To evaluate the Gram stain of deep tracheal aspirate as a tool to direct empiric antibiotic therapy, and more specifically as a tool to exclude the need for empiric antibiotic coverage against Staphylococcus aureus in ventilator-associated pneumonia (VAP). DESIGN: A prospective, single-center, observational, cohort study. SETTING: All wards at a community hospital. PATIENTS: Adult patients requiring mechanical ventilation, identified as having VAP in a 54-month prospective surveillance database. INTERVENTIONS: Sampling of lower airway secretions by deep endotracheal aspiration was taken from each patient who developed VAP. Samples were sent immediately for Gram stain and qualitative bacterial cultures. Demographic and relevant clinical data were collected; Gram stain, culture, and antibiotic susceptibility results were documented; and outcome was followed prospectively. MEASUREMENTS AND MAIN RESULTS: The analysis included 114 consecutive patients with 115 episodes of VAP from June 2007 to January 2012. Sensitivity of Gram stain compared with culture was 90.47% for gram-positive cocci, 69.6% for gram-negative rods, and 50% for sterile cultures. Specificity was 82.5%, 77.8%, and 79%, respectively. Negative predictive value was high for gram-positive cocci (97%) and sterile cultures (96%) but low for gram-negative rods (20%). Acinetobacter baumanii (45%) and Pseudomonas aeruginosa (38 %) were the prevailing isolates. S aureus was found in 18.3% of the patients. Most isolates were multiresistant. CONCLUSIONS: Absence of gram-positive bacteria on Gram stain had a high negative predictive value. These data can be used to narrow the initial empiric antibiotic regimen and to avoid unnecessary exposure of patients to vancomycin and other antistaphyloccocal agents.
Authors: Andre C Kalil; Mark L Metersky; Michael Klompas; John Muscedere; Daniel A Sweeney; Lucy B Palmer; Lena M Napolitano; Naomi P O'Grady; John G Bartlett; Jordi Carratalà; Ali A El Solh; Santiago Ewig; Paul D Fey; Thomas M File; Marcos I Restrepo; Jason A Roberts; Grant W Waterer; Peggy Cruse; Shandra L Knight; Jan L Brozek Journal: Clin Infect Dis Date: 2016-07-14 Impact factor: 9.079