Effect of Residual Gastric Volume on Risk of Ventilator-Associated Pneumonia in Adults Receiving Mechanical Ventilation and Early Enteral Feeding
Authors: Nashed Sherif Wadie , El Serwi Heba Bahaa El Din , El Derh Maha Sadek , Abdelmonem Aboarab Shady Abdelhalim 
Published: July 2024

Abstract

Background
Early enteral nutrition is the standard of care in critically ill patients receiving invasive mechanical ventilation. However, numerous studies have shown that early enteral nutrition is frequently not used. The main reason for nonuse is gastrointestinal intolerance to enteral nutrition which has been ascribed to gastroparesis with increased gastric volume, gastroesophageal reflux, and regurgitation or vomiting carrying a risk of aspiration and ventilator-associated pneumonia.

Aim of the Work
To test the hypothesis that the risk of ventilator-associated pneumonia is not increased when residual gastric volume is not monitored compared with routine residual gastric volume monitoring in patients receiving invasive mechanical ventilation and early enteral nutrition. Furthermore residual gastric volume monitoring may be associated with decreased calorie delivery and therefore, with underfeeding and increased morbidity.

Patients and Methods
This is a Prospective cohort study that was conducted at Ain Shams University Hospitals& Rashid General hospital for 6 months on critically ill patients admitted to ICU with mechanical ventilation. Sample sizes of 215 in each group totaling 430 in the study achieve 80% power to detect a non-inferiority margin difference between the group proportions of -0.0800. The reference group proportion is 0.158. The treatment group proportion is assumed to be 0.078 under the null hypothesis of inferiority.

Results
There was no significant difference between groups regard BMI (is calculated as weight in kilograms divided by height in meters squared), SAPS II or SOFA regard sex distribution the majority were male in both groups with no significant difference and also DM and HTN distributed with no significant difference between groups. Considering cause of admission and risk factors distribution between studied groups, in our study there is no significant difference or association between the two groups and the majority admission causes of both groups were respiratory and cancer. No significant difference between groups regard hospital stay or ICU days but MV days were significantly shorter in intervention group. In our study, Ventilator-Associated Pneumonia was significantly associated with control group as 47.4% had pneumonia while only 11.2% in intervention group had it. In the present study, cumulative calories deficit was significantly lower in intervention group, Intolerance and Prokinetic TTT were significantly associated with control group.

Conclusion
The current study supports the hypothesis that a protocol of enteral nutrition management without residual gastric volume monitoring is not inferior to a similar protocol including residual gastric volume monitoring in terms of protection against VAP. Residual gastric volume monitoring leads to unnecessary interruptions of enteral nutrition delivery with subsequent inadequate feeding and should be removed from the standard care of critically ill patients receiving invasive mechanical ventilation and early enteral nutrition.