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RecruitingNCT06751043FEEDSUpdated Jun 12, 2026

Preoperative Fasting vs. Not Fasting in Critically Ill Patients

An interventional study of Fasting and Not fasting in Critical Illness, Surgical Procedure, Unspecified and Pulmonary Aspiration, sponsored by Massachusetts General Hospital. Recruiting at 19 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-12.

Primary conditionFastingRegistry: Critical IllnessReclassifiedWhy we changed it
Registry
Critical Illness — the first condition term the registry derived for this study.
ClinicalTrials.gg
Fasting
Why
  1. Critical Illness is a broad heading, used only when no more specific condition is named.
  2. The study's listed conditions name Fasting.
Confidence
High: the new condition is named in the study's own listed conditions. Of 351 hand-checked studies reclassified this way, 68% were exactly right and 84% in the right disease family; the registry's first term was right for 5% (measured 2026-10-21). How we classify →
Wrong?
Tell us the study's main condition →

Sponsored by Massachusetts General Hospital · Not applicable, Interventional, and Prevention

From the registry’s dates

  • Started Apr 2025; still recruiting 1 year 6 months later.
Phase
Not applicable
Study type
Interventional
Enrollment
1,072
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

The goal of this clinical trial is to learn if fasting or not fasting before a procedure has an effect on recovery in those who are critically ill. The main questions it aims to answer for patients on a breathing machine who are receiving tube feeding are:

  • Does the risk of lung complications and death differ between those who are not fasting, which may have a higher chance of allowing tube feeding to enter the lungs, and fasting, which temporarily stops nutrition before a procedure?
  • Is there a difference in recovery times, hospital stays, infection rates, need for organ support, safety, and nutrition for those who either fast or do not fast before a procedure?
  • What is the relationship between nutrition and clinical outcomes?

Researchers will compare not fasting and fasting to see if it has an effect on recovery.

Participants will:

  • Be assigned by chance (like a coin toss) to one of two groups. One group (fasting group) will have their tube feeding stopped at least 8 hours before their procedure. The other group (not fasting group) will have their tube feeding stopped right before their procedure.

  • Be monitored via medical record for amount of protein and calories received, and any complications related to fasting/not fasting.

    • Data from routine electronic medical records will be reviewed to determine how participants are doing 3 months after their procedure.

'

Read the detailed description

Patient Population: Critically ill patients in the ICU who are: mechanically ventilated, receiving tube feeding (enteral nutrition), with a planned surgery or procedure. Up to 1072 subjects will be enrolled.

Phase III pragmatic multicenter parallel-group randomized controlled non-inferiority trial with patient-level randomization and assessor blinding.

Enrollment Period: Approximately two years.

Aims:

  • Aim 1: To compare the risk of pulmonary complications and mortality from: (1) perioperative pulmonary aspiration6,33,34 due to not fasting vs. (2) systemic effects of nutritional loss18-24 due to preoperative fasting. We will quantify the risk of pulmonary complications and mortality as the number of postoperative days alive and free from mechanical ventilation (DAFV)35,36 in the target population of critically ill patients with a secure airway who undergo interventional procedures.
  • Aim 2: To compare length of ICU and hospital stay, discharge to home, need for organ support, infectious complications, safety outcomes, and nutritional outcomes in tube-fed mechanically ventilated patients with a secure airway who are fasted vs. not fasted prior to procedure.
  • Aim 3: To define the relationship between perioperative fasting duration, calorie/protein delivery, and clinical outcomes in mechanically ventilated patients who receive tube feeding.

Study participants will be randomized with a 1:1 allocation ratio to one of the following preprocedural interventions:

  1. Fasting - stopping tube feeding at least 8 hours prior to the scheduled procedure time;
  2. Not fasting - tube feeding until call for transfer to the procedure area.
02

Conditions studied

  • Critical Illness
  • Surgical Procedure, Unspecified
  • Pulmonary Aspiration
  • Fasting

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Keywords

  • pulmonary aspiration
  • enteral nutrition
  • tube feeding
  • preoperative fasting
  • perioperative medicine
  • surgery in critically ill
  • procedures in critically ill
  • nutrition in critical illness
  • perioperative safety
  • preoperative management
  • preoperative fasting in secure airway
  • anesthesia in critically ill
03

In context

Fasting Reclassified

392 studies on the registry are indexed under Fasting; 63 are open to participants now.

This study's planned enrollment of 1,072 is above the median of 45 across 311 interventional studies indexed under Fasting.

Browse Fasting studies →

Lead sponsor

Massachusetts General Hospital is the lead sponsor of 2,586 studies on the registry; 447 are open to participants now.

Of its 222 completed or terminated interventional studies of FDA-regulated products, 168 (76%) have results posted.

Browse Massachusetts General Hospital studies →

Compared within Fasting, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Critical Illness. The counts are of registry records indexed under each term, refreshed daily. How we classify →

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. 1. Age ≥ 18
  2. Current admission to ICU*
  3. Secure airway** with no plans for its removal prior to procedure
  4. Current non-trophic (> 10 mL/hr) tube (enteral) feeding*** with no plans to discontinue prior to procedure for reasons other than preoperative fasting

  5. Planned eligible procedure (Examples are listed in Appendix C) with anesthesia care or nursing sedation. Eligible procedures are defined as non-emergent diagnostic or therapeutic interventions that:

    • Do NOT have a well-established practice of preoperative fasting. (For example, bedside placement of a vascular catheter [arterial, central venous, peripheral venous] by the ICU team is NOT eligible for this trial since it has a widely established practice of no preoperative fasting and is not generally scheduled for a specific time.)
    • Do NOT require fasting for preoperative gastrointestinal tract preparation
    • Do NOT require removal/replacement of the endotracheal or tracheostomy tube
    • Do NOT require prone or Trendelenburg (head-down) positioning.
    • Typically require procedural sedation or anesthesia care.
    • Generally, are scheduled for a specific time (although this time can change, or procedure may be cancelled).

    • Are performed in the operating room, non-operating room procedural areas, or at the patient's bedside.

      • All ICU types are eligible: surgical, medical, cardiac, neurological, trauma, mixed etc.

        • Secure airway is defined as a cuffed endotracheal tube or a cuffed tracheostomy tube.

          • Patients with all types of feeding tubes are eligible, regardless of tube insertion site (nasal, oral, surgically implanted) and tube tip location (pre- and post-pyloric) †As determined by the enrolling physician-investigator

Exclusion criteria

Exclusion Criteria

  1. Inability to obtain
  2. Inability to enroll and randomize > 8 hours prior to planned procedure time
  3. Inability to deliver trial interventions
  4. Expected survival \< 48 hours as determined by the enrolling physician-investigator
  5. Critically ill burn patient
  6. Emergency procedure
  7. a. Gastrointestinal tract procedure that requires fasting based on surgical indications or b. airway/lung procedure that requires removal of endotracheal or tracheostomy tube
  8. Plan for prone or Trendelenburg (head down) positioning during most of the procedure
  9. Major impairment of gastrointestinal motility or major structural disease of the gastrointestinal tract (e.g., severe gastroparesis, bowel obstruction, severe ileus, severely compromised lower esophageal sphincter, active gastrointestinal bleeding)
  10. Plan for postoperative extubation in the procedure area
  11. Prisoner
  12. Pregnant woman, woman of without a documented negative urine or serum pregnancy test during the current hospitalization, or woman who is breast feeding
  13. Refusal to enroll patient by treating physician
  14. Extracorporeal Membrane Oxygenation (ECMO) at the time of potential enrollment, except patients scheduled for ECMO decannulation as the study procedure and patients expected to be off of ECMO at the time of study procedure.
  15. Chronic mechanical ventilation at pre-admission level of care
Terms in these criteria, in plain language(2)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

05

Study design

Phase
Not applicable
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Outcomes assessor)
Enrollment
1,072 participants (estimated)

Study arms

  • Active comparator
    Fasting

    Patients randomized to the Fasting arm will have tube feeding stopped at least 8 hours before the scheduled surgery or procedure time.

    Other: Fasting

  • Active comparator
    Not Fasting

    Patients randomized to the Not Fasting arm will have tube feeding continued until transfer to the operating room/procedure area.

    Other: Not fasting

Interventions

  • OtherFasting

    Process: Fasting pre-procedure Tube feeding will be stopped at least 8 hours before the patient's scheduled surgery or procedure time.

  • OtherNot fasting

    Process: Not fasting pre-procedure Tube feeding will be continued until patient transfer to the operating room/procedure area.

06

What researchers measure

Primary outcomes

  1. Days alive and free from mechanical ventilation on postoperative day 28.

    Defined as the days alive and free of organ support (dialysis, assisted ventilation, and vasopressors) to day 28. Participants will need to be free of all three components (assisted ventilation, vasopressors, new renal replacement therapy) to qualify for a day alive and free from organ failures. Patients on chronic dialysis will not be scored for the new renal failure free component of this outcome.

    Time frame: Post-operative day 28

Secondary outcomes

  1. Postoperative mortality

    Death from any cause at any location, including deaths after withdrawal of care.

    Time frame: Post-operative day 28

  2. Ventilator-free days in survivors

    28 minus last post-operative day of mechanical ventilation assessed only in survivors at post-operative day 28. Non-survivors are excluded

    Time frame: Post-operative day 28

  3. All-cause, all-location mortality

    Death from any cause at any location, including deaths after withdrawal of care.

    Time frame: Post-operative day 90

  4. Length of ICU stay

    90 minus the last post-operative day of ICU admission.

    Time frame: Post-operative day 90

  5. Length of hospital stay

    90 minus the last post-operative day of hospital/facility admission.

    Time frame: Post-operative day 90

  6. Days alive and without life support54 Days alive and without life support

    90 minus the last post-operative day of mechanical ventilation, renal replacement therapy, or circulatory support (ECMO, vasopressor or inotrope), whichever is used last.

    Time frame: Post-operative day 90

  7. Proportion of patients alive and at home

    Proportion of patients who are alive and at home or at pre-index hospitalization level of care.

    Time frame: Post-operative day 90

  8. New surgical site infection

    Documentation of superficial incisional or organ/space infection after index procedure in routine medical records

    Time frame: Post-operative day 90

  9. New bacteremia

    Bacteremia in patients without pre-study intervention evidence of bacteremia during the same hospital admission.

    Time frame: Post-operative day 90

  10. Perioperative pulmonary aspiration

    Periprocedural pulmonary aspiration of gastric contents documented in routine medical records.

    Time frame: Time of procedure start +/- 24 hours

  11. Perioperative Hyperglycemia

    Routinely collected blood glucose of \> 180 mg/dL on at least one measurement.

    Time frame: Time of procedure start +/- 24 hours

  12. Perioperative hypoglycemia

    At least one episode of routinely collected blood glucose of 41 to 70 mg/dL (moderate hypoglycemia) or ≤ 40 mg/dL (severe hypoglycemia).

    Time frame: Time of procedure start +/- 24 hours

  13. Preoperative fasting duration

    Time from last routinely documented non-trophic (\> 10 mL/hr) tube feeding to procedure start.

    Time frame: Time of procedure start - 72 hours

  14. Postoperative fasting duration

    Time from procedure end to the first routinely documented non-trophic (\>10 mL/hr) tube feeding volume/rate.

    Time frame: Time of procedure start + 72 hours

  15. Perioperative fasting duration

    Duration of preoperative plus postoperative fasting.

    Time frame: Time of procedure start +/- 72 hours

  16. Preoperative calories delivered

    Total number of calories delivered via tube feeding within 24 and 72 hours prior to procedure.

    Time frame: Time of procedure - 72 and -24 hours

  17. Postoperative calories delivered

    Total number of calories delivered via tube feeding within 24 and 72 hours after the procedure.

    Time frame: Time of procedure + 72 and + 24 hours

  18. Perioperative calories delivered

    Total number of calories delivered via tube feeding within 24 and 72 hours of the procedure.

    Time frame: Time of procedure +/- 72 and +/- 24 hours

  19. Preoperative protein delivered

    Total amount of protein delivered via tube feeding within 24 and 72 hours prior to procedure.

    Time frame: Time of procedure - 72 and -24 hours

  20. Postoperative protein delivered

    Total amount of protein delivered via tube feeding within 24 and 72 hours after the procedure.

    Time frame: Time of procedure + 72 and + 24 hours

  21. Perioperative protein delivered

    Total amount of protein delivered via tube feeding within 24 and 72 hours of the procedure

    Time frame: Time of procedure +/- 72 and +/- 24 hours

07

Study locations

13 of 19 sites recruiting
08

References and documents

Individual participant data

Plan to share: Yes — Study sites of this trial will share deidentified data through eCRF with the Statistical and Data Coordinating Center. The shared data will include patient baseline characteristics (clinical and demographic), data on trial interventions, and outcome data.

Supporting information: Study protocol, Statistical analysis plan, Informed consent form

Time frame: Upon completion of the study, the final cleaned and locked data set will be deidentified per the HIPAA Privacy Rule (45 C.F.R. § 164.514(b)). The deidentified Full Data Package will be deposited in the Patient-Centered Outcomes Data Repository (PCODR) at the Inter-university Consortium for Political and Social Research (ICPSR) at the University of Michigan.

Access criteria: Access to the data will be based on the regulations of the Patient-Centered Outcomes Data Repository (PCODR) at the Inter-university Consortium for Political and Social Research (ICPSR) at the University of Michigan.

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Apr 2025 (actual). Primary completion is estimated for Feb 2028, 34 months after the start.

Of 144 non-industry interventional studies with no phase under Fasting, half reached primary completion within 19 months of starting (the median), counting those still running; a quarter within 6 and three quarters within 40. This study's planned 34 months is above that.

Counting every sponsor, half of 149 studies reached it within 18 months; a quarter within 6 and three quarters within 40.

How these figures are worked out, and which studies are left out of them.

Registered
Dec 20, 2024
First posted
Dec 27, 2024
StartActual
Apr 28, 2025
Primary completionEst.
Feb 2028
CompletionEst.
May 2028
Last update
Jun 12, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Jun 12, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06751043
Lead sponsor
Massachusetts General Hospital
Collaborators
Patient-Centered Outcomes Research Institute, Columbia University
Responsible party
Alexander Nagrebetsky, MD MSc (Anesthesia Attending, Massachusetts General Hospital) — Principal investigator
First posted
Dec 27, 2024
Start date
Apr 28, 2025
Primary completion
Feb 2028 (estimated)
Completion
May 2028 (estimated)
Last update
Jun 12, 2026

Study contacts

Alexander Nagrebetsky, MD, MSC
Contact
anagrebetsky@mgh.harvard.edu
617-724-3292
Alexander Nagrebetsky, MD, MSC
principal investigator · Massachusetts General Hospital

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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