The Million Anesthesia Cases Study (MACS) - Preoperative Fasting and Outcomes

This study, called The Million Anesthesia Cases Study (MACS), is looking at how long people fast (don't eat or drink) before surgery and how that affects their health outcomes. Researchers believe that not eating or drinking for too long before a procedure might actually be harmful, potentially causing issues like anxiety, hunger, thirst, low blood pressure (hypotension), and problems with blood sugar. The study will look at a very large number of patients (1,200,000) who are having a diagnostic or therapeutic procedure with anesthesia (general anesthesia, regional anesthesia, or sedation). The main things they're looking for are nausea and vomiting after surgery, low blood pressure during surgery, and kidney injury in the days following surgery. This is an observational study, meaning researchers will be watching and collecting information, not giving a new treatment.

Study design
This is an observational study involving 1,200,000 participants. Researchers will observe the duration of preoperative fasting and its effects.
What's involved
Not specified in the trial record.
Compensation
Not stated in the trial record.
Follow-up
The study measures outcomes like postoperative nausea and vomiting at 12 hours post-surgery, and acute kidney injury up to 7 days after surgery.

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NCT07022951

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

Recruiting
Not specifiedAll AgesObservational
Massachusetts General Hospital
~1,200,000 participants
Updated 2026-04-08 on ClinicalTrials.gov
What's tested:Preoperative fasting

At a glance

Recruiting sites
1 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Postoperative nausea and vomiting (PONV)
Measured over 12 hours postoperatively
+2 more outcomes measured
Anesthesia
Sedation
Monitored Anesthesia Care
Procedure
Surgery, Day
Surgery
Surgery Scheduled
Fasting Before Operation
Aspiration; Gastric Contents, Anesthesia
1 sites across 1 states
Massachusetts1

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Eligibility criteria

Inclusion

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

Exclusion

Not receiving anesthesia care
Lack of medical record data in Epic electronic medical record system
  • Postoperative nausea and vomiting (PONV)12 hours postoperatively

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

  • Intraoperative hypotensionIntraoperative period.

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

  • Perioperative acute kidney injury (AKI)Postoperative days 0 to 7

    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