The Million Anesthesia Cases Study (MACS) - a Cohort Study of Preoperative Fasting and Perioperative Outcomes

NCT07022951 | Recruiting

• 1 other identifier: 2023P001743
• Study Type: observational
• Target: 1,200,000
• Locations: 1 country
• Sites: 1

Brief Summary

Perioperative fasting has historically been viewed as a low-risk intervention. However, preliminary data indicate that perioperative loss of nutrition and fluids is likely harmful. This study intends to characterize perioperative fasting practices and their potential effects on clinical outcomes through possible effects on patient well-being (anxiety, hunger, thirst), physiology (hypovolemia, hypotension), perioperative aspiration, etc. The research team hypothesized that in addition to known adverse effects on patients' well-being, prolonged preoperative fasting adversely affects circulating blood volume-related (hypotension, decreased urine output etc.) and glucose metabolism-related (e.g., hypo/hyperglycemia) perioperative physiology. The investigators will also test for an association between the duration of preoperative fasting and the risk of perioperative pulmonary aspiration. Additional knowledge on the potential adverse effects of preoperative fasting will inform preoperative fasting policies and research interventions that are relevant to hundreds of millions of patients subjected to preoperative/preprocedural fasting worldwide each year.

Conditions

Anesthesia; Sedation; Monitored Anesthesia Care; Procedure; Surgery, Day; Surgery; Surgery Scheduled; Fasting Before Operation; Aspiration; Gastric Contents, Anesthesia

Keywords

preoperative fasting; perioperative pulmonary aspiration; perioperative complications; postoperative nausea and vomiting; perioperative hypoglycemia; perioperative hyperglycemia; perioperative hypotension; myocardial injury after noncardiac surgery; perioperative acute kidney injury; clear liquid fasting

Outcome Measures

Primary Outcomes (3)

• Postoperative nausea and vomiting (PONV)

  The co-primary outcome of PONV is defined as administration ≥ 1 antiemetic drug within 12 h postoperatively.

  12 hours postoperatively

• Intraoperative hypotension

  The co-primary outcome of intraoperative hypotension is defined as an area under the curve of intraoperative mean arterial pressure \<65 mm Hg.

  Intraoperative period.

• Perioperative acute kidney injury (AKI)

  The co-primary outcome of perioperative AKI is defined as stage 1 or higher, based on Kidney Disease Improving Global Outcomes criteria (creatinine rise ≥ 0.3 mg/dl within 48 h or ≥ 1.5 times baseline) from postoperative day (POD) 0 until POD 7

  Postoperative days 0 to 7

Secondary Outcomes (6)

• Incidence of prolonged preoperative fasting for clear liquids

  48 hours preoperatively

• Severity of prolonged clear liquid fasting

  48 hours preoperatively

• Perioperative hypoglycemia

  12 hours preoperatively to 24 hours postoperatively

• Perioperative hyperglycemia

  12 hours preoperatively to 24 hours postoperatively

• Perioperative AKI stage 2 or higher.

  Postoperative days 0 to 7

Other Outcomes (1)

• Safety outcome: Perioperative pulmonary aspiration

  Intraoperative period to 24 hours postoperatively

Study Arms (1)

Patients who receive anesthesia care

Other: Preoperative fasting

Interventions

Preoperative fasting OTHER

This cohort study assesses the duration of preoperative fasting and its clinical effects

Patients who receive anesthesia care

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

We will include all anesthesia cases at participating institutions.

You may qualify if:

• Diagnostic or therapeutic procedure with anesthesia care (general anesthesia, regional anesthesia, sedation, or a combination of the above)

You may not qualify if:

• Not receiving anesthesia care
• Lack of medical record data in Epic electronic medical record system

Sponsors & Collaborators

• Anesthesia Patient Safety Foundation (APSF): collaborator
• Massachusetts General Hospital: lead

Study Sites (1)

Mass General Brigham Hospital Network of secondary, tertiary, and quaternary care hospitals

Boston, Massachusetts, 02114, United States

RECRUITING

MeSH Terms

Conditions

Postoperative Nausea and Vomiting

Condition Hierarchy (Ancestors)

Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Nausea; Signs and Symptoms, Digestive; Signs and Symptoms; Vomiting

Central Study Contacts

Alexander Nagrebetsky, MD, MSc

CONTACT

617-724-3292; anagrebetsky@mgh.harvard.edu

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: OTHER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Physician-Investigator

Study Record Dates

• First Submitted: June 6, 2025
• First Posted: June 15, 2025
• Study Start: January 1, 2016
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2030
• Last Updated: April 8, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)