Role of suctioning airway secretions in reducing lung infection in ICU patients requiring artificial breathing

INTERVENTION: Intervention1: Subglottic suctioning in addition to routine endoracheal suctioning: Subglottic suctioning involves clearance of the sectretions which get accumulated between the inflated bulb of the endotracheal tube and the vocal cords. This site is not accessible routinely however the Hi Lo EVAC tubes contain additional port opening in the subglottic space enabling the suction of secretions. Control Intervention1: routine endotracheal suctioning: Routine endotracheal suctioning involves a sterile catheter insertion through the endotracheal tube into the airway and clearing the secretions in the larynx. This however does not clear the pool of secretions in the subglottic space which is known to harbor pathogenic organisms responsible for causing ventilator associated pneumonia. CONDITION: Ventilator associated pneumonia PRIMARY OUTCOME: Incidence of Ventilator associated pneumonia.‐‐‐‐‐‐Timepoint: During the ICU stay. SECONDARY OUTCOME: Time to VAP diagnosis ; Mortality rate ; Duration of ICU stay‐‐‐‐‐‐Timepoint: During ICU stay INCLUSION CRITERIA: All patients requiring Medical ICU admission for invasive mechanical ventilation will be recruited into the study.