Project Summary

Background and Significance:
The goal of this study is to prevent unnecessary starvation in critically ill patients who are connected to the ventilator and need tube feeding. In these patients, feeding is often stopped before a scheduled surgery or procedure, although doctors are not sure if withholding tube feeding is necessary. Patients usually spend 8-15 hours, sometimes days, without nutrition because procedures are regularly delayed or postponed until the next day. 

Patients are usually asked not to eat before surgery/procedures to prevent vomiting and pulmonary aspiration while they are unconscious during the procedure. This practice is relatively harmless and can be justified in healthy patients. However, fasting recommendations for healthy patients are regularly applied to critically ill patients who have a breathing (endotracheal) tube used for mechanical ventilation. In patients with a breathing tube, fasting is likely: 1) unnecessary because the breathing tube protects the lungs from vomiting/aspiration, and 2) harmful due to poor nutrition in patients who spend a long time in the intensive care unit (ICU) and are commonly underfed. 

No reliable studies have been done to test whether fasting or not fasting is better in patients who go to the operating room from the ICU and have a breathing tube. Hospitals treat patients whose lungs are protected by a breathing tube differently; some stop feeding patients a long time before surgery, while others continue tube feeding until surgery or even during surgery. This lack of knowledge on whether to stop tube feeding before the procedure or not affects about 100,000 critically ill patients in the United States each year. Researchers will conduct a high-quality study to answer the question of whether stopping tube feeding a long time before surgery/procedures (also known as fasting) is necessary in patients who are in the ICU on a ventilator and whose lungs are protected from aspiration by the breathing tube. 

Study Aims: 

Aim 1: To test how fasting or not fasting before the procedure changes the number of days patients are alive and free from ventilation at one month after the procedure 

Aim 2: To assess how fasting or not fasting before the procedure changes patient safety around the time of the procedure, their recovery from critical illness over the course of 90 days after the procedure and the amount of nutrition patients receive. 

Aim 3: To test if people who spent more time without nutrition or received fewer calories and protein will do worse than those who spent less time fasting and received more calories   

Study Description: 
In this study, patients will be randomly assigned to: 

  • Fasting: stopping tube feeding at least eight hours before the procedure
  • Not fasting: tube feeding until call for transfer from the ICU to the procedure area 

Population: The study will include 1,048 patients aged 18 or older who are on a ventilator in the ICU, receive tube feeding, and need a procedure. Researchers will exclude procedures where doctors are sure that stopping tube feeding is helpful. They will include patients from all types of ICUs across 17 hospitals around the country to ensure they include people of different race, ethnicity and sex.

Information on outcomes in study participants will come primarily from their medical records. Researchers will also call patients 90 days after the procedure to assess their quality of life. 

Primary outcome: Days alive and free from mechanical ventilation on postoperative day 28, an outcome that captures the complications of perioperative pulmonary aspiration (the feared complication of not fasting) as well as the complications of nutrition loss (due to fasting) in mechanically ventilated tube-fed patients.

Secondary outcomes: Postoperative mortality; ventilator-free days in survivors (non-survivors excluded); all-cause, all-location mortality; length of ICU and hospital stay; days alive and without life support; proportion of patients alive and at home; health-related quality of life; new surgical site infection; new bloodstream infections; perioperative vomiting/aspiration; perioperative blood sugar; perioperative fasting duration, calories and protein delivered.   

The team that planned this study includes patients, their families, nurses, doctors and scientists. While designing this study, researchers met with patients and healthcare professionals to ensure the study answers a relevant question and that the team measures the results of this study in a way that is meaningful to both patients and clinicians.

Project Information

Alexander Nagrebetsky, M.D., M.S.
Marcos Francisco Vidal Melo, M.D., Ph.D.
Massachusetts General Hospital/Harvard Medical School
$7,452,875 *

Key Dates

48 months *
November 2023

*All proposed projects, including requested budgets and project periods, are approved subject to a programmatic and budget review by PCORI staff and the negotiation of a formal award contract.


Award Type
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: January 24, 2024