impact of onset time on the isolated pathogens and outcomes in ventilator associated pneumonia

Several guidelines base the empirical therapy of ventilator-associated pneumonia [VAP] on the time of onset. However, there is emerging evidence that the isolated microorganisms may be similar regardless of onset time. This study evaluated the characteristics and outcomes of VAP with different onset times. All of the mechanically ventilated patients admitted to the ICU of a 900-bed tertiary-care hospital between 01/08/2003 and 31/12/2010 were prospectively followed for VAP development according to the National Healthcare Safety Network criteria. The patients were categorized into four groups: EO if VAP occurred within 4 days of intubation and hospital admission; LO if VAP occurred after 4 days of admission; EL if VAP occurred within 4 days of intubation, but after the fourth hospitalization day; and LL if VAP occurred after the fourth day of intubation and hospitalization. Out of the 394 VAP episodes, 63 [16%] were EO episodes, 331 [84.0%] were LO episodes, 40 [10.1%] were EL episodes and 291 [73.1%] were LL episodes. The isolated microorganisms were comparable among the four groups, with a similar rate of potentially multidrug resistant organisms in the EO-VAP [31.7%], LO-VAP [40.8%], EL-VAP [37.5%] and LL-VAP [43.3%] samples. The hospital mortality was 24% for EO-VAP cases, 28% for LO-VAP cases, 40% for EL-VAP cases and 49% for LL-VAP cases. However, in the adjusted multivariate analysis, neither LO-VAP, EL-VAP nor LL-VAP was associated with an increased risk of hospital mortality compared with EO-VAP [OR, 0.86 95% CI, 0.34-2.19; 1.22; 95% CI, 0.41-3.68, and 0.95; 95% CI, 0.43-2.10, respectively]. In this study, the occurrence of potential multidrug resistant pathogens and the mortality risk were similar regardless of VAP timing from hospital admission and intubation. The bacterial isolates obtained from the VAP cases did not follow an early vs. late-onset pattern, and thus, these terms may not be clinically helpful

Drug-resistant ventilator associated pneumonia in a tertiary care hospital in Saudi Arabia

There is a wide geographic and temporal variability of bacterial resistance among microbial causes of ventilator-associated pneumonia [VAP]. The contribution of multi-drug resistant [MDR] pathogens to the VAP etiology in Saudi Arabia was never studied. We sought to examine the extent of multiple-drug resistance among common microbial causes of VAP. We conducted a retrospective susceptibility study in the adult intensive care unit [ICU] of King Abdulaziz Medical City, Riyadh, Saudi Arabia. Susceptibility results of isolates from patients diagnosed with VAP between October 2004 and June 2009 were examined. The US National Healthcare Safety Network definition of MDR was adopted. A total of 248 isolates including 9 different pathogens were included. Acinetobacter spp. was highly [60-89%] resistant to all tested antimicrobials, including carbapenems [three- and four-class MDR prevalence were 86% and 69%, respectively]. Pseudomonas aeruginosa was moderately [13-31%] resistant to all tested antimicrobials, including antipseudomonal penicillins [three- and four-class MDR prevalence were 13% and 10%, respectively]. With an exception of ampicillin [fully resistant], Klebsiella spp. had low [0-13%] resistance to other tested antimicrobials with no detected MDR. Staphylococcus aureus was fully susceptible to vancomycin with 42% resistance to oxacillin. There were significant increasing trends of MDR Acinetobacter spp. However not P. aeruginosa during the study. Resistant pathogens were associated with worse profile of ICU patients but not patients' outcomes. Acinetobacter in the current study was an increasingly resistant VAP-associated pathogen more than seen in many parts of the world. The current finding may impact local choice of initial empiric antibiotics.