The great quality meanwhile and quantity of the respiratory research in such a dynamic and opportune time will impact patient care.AbbreviationsALI: acute lung injury; ARDS: acute respiratory distress syndrome; CT: computed tomography; EBC: exhaled breath condensate; EELV: end-expiratory lung volume; FiO2: fractional inspired oxygen; ICU: intensive care unit; NPPV: noninvasive positive-pressure mechanical ventilation; PaO2: arterial oxygen tension; PAPC: 1-palmitoly-2-arachidonoyl-sn-glycero-3-phosphorylcholine; PARP: poly (ADP-ribose) polymerase; PEEP: positive end-expiratory pressure; VILI: ventilator-induced lung injury.Competing interestsThe authors declare that they have no competing interests.
Ventilator associated pneumonia (VAP) refers specifically to nosocomial pneumonia that has developed in patients who are receiving mechanical ventilation.

VAP that occurs within 48 to 72 hours after tracheal intubation is usually termed early-onset pneumonia; it often results from aspiration, which complicates the intubation process [1].One of the most common recognized risk factors for VAP is the bacterial colonization of the gastric content with subsequent gastro-esophageal reflux (GER) and aspiration into the airways [2].In mechanically ventilated patients in the pediatric intensive care unit (PICU), the physiological environment differs substantially from that in the awake subject [3]. Low or absent lower esophageal sphincter (LES) pressure in critically ill patients may be due to many factors including drugs such as adrenergic agonists, bronchodilators and opiates used for sedation during mechanical ventilation.

Also, hypotension and sepsis may contribute [4].The acid clearance of the esophagus is a two-step process: volume clearance by esophageal peristalsis followed by chemical neutralization by swallowed salivary bicarbonate. Both of these elements are likely to be severely impaired in ventilated patients, as well as the esophageal motility being markedly impaired and salivary secretion being diminished by sleep [5]. Also supine body positioning is one of the most important predisposing factors of GER and aspiration in mechanically ventilated patients [6].We hypothesized that GER occurs in ventilated non-pneumonic infants and children and is possibly a predisposing factor for VAP development in such patients.

So the aim of the work was to determine the frequency of GER in mechanically ventilated Drug_discovery patients and its role as a risk factor for VAP.Materials and methodsThis prospective cohort study was conducted in the PICU of the Ain Shams University Children’s Hospital. In this PICU the admission rate is 30 patients per month, with the total mortality in 2007 being 30%. The overall rate of mechanical ventilation in the same year was 70% with half of these patients developing VAP.