Abstract: Acute viral respiratory tract infections, particularly acute viral lower respiratory tract infections, are a prevalent etiology of severe pediatric respiratory illness. In addition to the harm caused by viral replication itself, excessive inflammatory responses and immune homeostasis imbalances in the body can trigger cytokine storms, resulting in severe tissue and organ damage, and leading to multiple organ dysfunction or even mortality. With the continuous promotion and application of various etiological detection techniques in clinical practice, early and accurate diagnosis of the virus can be achieved. Reasonable selection of antiviral drugs, standardized implementation of non-drug intervention measures, and active immunization are helpful to prevent and control infection.

Objective To discuss the feasibility of preoperative diet by measuring gastric emptying time of carbohydrate and protein nutrient solutions in healthy volunteers.Methods A total of 20 healthy volunteers were collected from August 2013 to May 2014.On the morning of the trial,baseline gastric residual volume of each volunteer was measured with magnetic resonance imaging at 8 a.m.,then each of the 20 healthy volunteers took 12.5％ carbohydrate solution 400 ml (containing 40 g of maltodextrin and 10 g of sucrose) or 12.5％ whey protein solution (containing 50 g whey protein) in 5 minutes.Magnetic resonance imaging was conducted to measure the gastric residual volume every 25 minutes.The volunteers were shifted to the other nutrient solution after a 1-week interval.The gastric emptying time of both nutrient solutions was calculated to generate the curves illustrating the process of gastric emptying.Results The baseline gastric residual volume of the volunteers was (14.90 ± 9.39) ml.The total gastric emptying time of carbohydrate solution was (104.90 ± 27.98) min (95 ％ CI 98.64-111.16 min),while that of whey protein solution was (199.6 ± 34.17) min (95％ CI 184.47-214.73 min).There was a significant difference between these two types of nutrient solution in terms of gastric emptying time (P ＜ 0.000 1).Conclusions The induction of anesthesia could be performed 2 hours after carbohydrate administration,and at least 4 hours after whey protein administration.