<prompt> Which of the following is an ideal method to prevent aspiration pneumonia?Endotracheal tube cuffedInhalational anestheticIncrease the intra abdominal pressureFull stomach  <response>: Ans: a Endotracheal tube cuffed Ref: Ajay Yadav, p. 97Cuffed endotracheal tube is an ideal method to prevent aspiration pneumoniaPulmonary aspiration 1 in 3000 Most common cause of death associated with anaesthesia Normal intragastric pressure is 5 - 7 cm of water and regurgitation is prevented by tone of lower esophageal sphincter LES A pressure of 20 cm of water is required to overcome LES tone Predisposing factorsa Full stomach-most important factorb Depressed level of consciousnessc Conditions decreasing the tone of LES Pregnancy Mendelson syndrome- acid aspiration in late pregnancy Abdominal tumours Obesity Hiatus hernia Presence of nasogastric tube Drugsd Conditions delaying gastric emptying Diabetes Hypothyroidism Narcotics Pain Anxiety AnticholinergicsAtropine glycopyrrolateOpiodsThiopentoneSodium nitroprussideDopamineHalothaneGanglion blockersPathology:Chemical trauma to bronchial and alveolar mucosa and injury to vascular endothelium can cause exudative pneumonitis or pulmonary edema ARDSNote: Selliks maneuver - If GA is to be given in full stomach it should be rapid sequence crash intubation while the assistant maintains the cricoid pressure.Segments of lung affected in foreign body aspiration In supine position most commonly involved segment is apical segment of right lower lobe In lateral position most commonly involved segment is posterior segment of upper lobe right upper lobe in rt lateral and left upper lobe in left lateral In standing sitting position aspiration most commonly occurs in posterior basal segment of right lower lobe 