Assessment of gastric volume and gastric content in patient undergoing elective cardiac surgery using ultrasonography.

Pulmonary aspiration of the gastric contents is a serious perioperativecomplication.  The overall incidence in a mixed surgicalpopulation ranges between <0.1% and 19% depending on patient and surgicalfactors and it has not changed in the last few decades. Aspiration pneumonia is associated with significantmorbidity, including prolonged mechanical ventilation, and carries a risk of mortality asgreat as 5%. Pulmonary aspiration is involved in up to 9% of allanaesthesia-related deaths. One of the main risk factors for aspiration is the presence of gastriccontent. The critical volume threshold of gastric fluid that by itselfincreases aspiration risk is controversial, but healthy, fasted patientsfrequently have residual gastric volumes (GVs) of up to 1.5 ml kg−1 without significant aspiration risk. Sedation and general anaesthesia depress or impedethe physiological mechanisms that protect against aspiration (the tone of thelower oesophageal sphincter and upper airway reflexes). Since restriction of fluid and food intake beforegeneral anaesthesia is vital for patient safety, anaesthesiology societies havedeveloped guidelines for preoperative fasting.. In preoperative fasting guidelines, atleast 2 hours for clear liquids is recommended, 6 hours of fasting for liquidscontaining solid particles and toasted sandwich type solid foods, and 8 hoursof fasting for high calorie and fatty foods. Patients with BMI over 30 and type 2 diabetes may benefitfrom point of care ultrasonography to guide perioperative airway management bystratifying gastric residual volume**.** The evaluation of gastric content byultrasound is a good method to qualitatively and quantitatively assess thegastric volume and thus determine the risk of perioperative pulmonaryaspiration.As cardiac surgeries are longduration surgeries so case posted in afternoon shift  have a prolong fasting period . As per presentCVTS protocol all the patients are kept fasted from midnight so to avoid thisprolong fasting we can do sonography of stomach preoperatively to decidewhether it is needed to keep patient fasting from midnight or we can keep themfasted from morning when posted for afternoon schedule.