The duration of MV increases the risk of infection. Cook et al. [22] reported a cumulative increased risk of VAP with time, with 3% per day in the first week of MV, 2% per day in the second week, and 1% per day in the third week. In other studies, similarly, it was shown that the risk of pneumonia increased by the duration of MV and the highest risk was during the first 8-10 days [36] [37] [38] . The need for reintubation, urgent intubation and documented massive aspiration are also associated with high incidence of VAP [1, 21, 29, 39] .