Determinants of ventilator associated pneumonia and its impact on prognosis: A tertiary care experience

BACKGROUND: Ventilator associated pneumonia (VAP) is a major cause of poor outcome among patients in the intensive care units (ICU) world-wide. We sought to determine the factors associated with development of VAP and its prognosis among patients admitted to different ICUs of a Tertiary Care Hospital in India. METHODOLOGY: We did a matched case control study during October 2009 to May 2011 among patients, ≥18 years with mechanical ventilation. Patients who developed pneumonia after 48 h of ventilation were selected in the case group and those who did not develop pneumonia constituted the control group. Patients’ history, clinical and laboratory findings were recorded and analyzed. RESULTS: There were 52 patients included in each group. Among cases, early onset ventilator associated pneumonia (EVAP) occurred in 27 (51.9%) and late onset ventilator associated pneumonia (LVAP) in 25 (48.1%). Drug resistant organisms contributed to 76.9% of VAP. Bacteremia (P = 0.002), prior use of steroid/immunosuppressant (P = 0.004) and re-intubations (P = 0.021) were associated with the occurrence of VAP. The association of Acinetobacter (P = 0.025) and Pseudomonas (P = 0.047) for LVAP was found to be statistically significant. Duration of mechanical ventilation (P = 0.001), ICU stay (P = 0.049) and requirement for tracheostomy (P = 0.043) were significantly higher in VAP. Among each case and control groups, 19 (36.5%) expired. CONCLUSION: We found a higher proportion of LVAP compared with EVAP and a higher proportion of drug resistant organisms among LVAP, especially Pseudomonas and Acinetobacter. Drug resistant Pseudomonas was associated with higher mortality.