Ventilator associated pneumonia (VAP) is a common complication of ventilatory support for patients
with acute respiratory failure, currently related to high mortality rate. Therefore, this complication of
mechanical ventilation requires a prompt diagnosis and adequate antibiotic treatment. The study aimed
to investigate the role of endotracheal aspirate (ETA) surveillance cultures in identifying the aetiology
of VAP earlier. The study was conducted over a period of 12 months and included 152 patients under
mechanical ventilation for >48 h from different ICUs of Assiut University Hospitals. Quantitative cultures
of ETA at threshold of 10
5cfu/ml were performed. The organisms were primarily identified by colony
morphology, microscopy of Gram stain and standard biochemical tests. The antibiotic resistance
pattern of the isolated bacteria was determined by Kirby-Bauer disk diffusion method. VAP was
suspected in 92/152 patients (60.53%). Microbiological support for VAP was obtained by ETA in 90
patients. Positive cultures occurred in 88 patients, the infection was polymicrobial in 50 (54.34%) of
cultures. Major isolated pathogenic bacteria were gram negative (54.79%);
Klebsiella species was the
commonest organism (23.29 %). Gram positive bacteria were detected in 42.47% of the cultures;
methicillin resistant
Staphylococcus aureus (MRSA) was the predominant organism (24.40%). Gram
negative bacteria showed high resistance to penicillins, cephalosporins and quinolones, the least
resistance was to imipenem. Mortality was higher in VAP group (47.8%) than non VAP (30%). It is
indicated that quantitative cultures of ETA is a useful method for early diagnosis of VAP with
subsequent proper selection of adequate therapy.