Reassessing strict BMI criteria in ambulatory surgery in the context of regional anesthesia for patients BMI ≥40

BACKGROUND

Traditional concerns for primary regional anesthesia in high-BMI patients:
Increased comorbidities
Increased regional failure rate
Increased unplanned admissions

Many ambulatory surgical centers have strict BMI criteria

METHODS

Epic SlicerDicer identified surgical cases of interest at a university ambulatory surgical center

Inclusion criteria:
BMI 40-49 and BMI ≥50 at time of surgery
Primary regional, spinal, or epidural anesthesia

Cases examined for:
Notable events (Table 1)
Final airway (natural patent airway, ETT, or LMA)
Days to readmission (<10, 10-20, 20-30, 30+, or none)

RESULTS

From September 2022 to December 2025:

No notable events or conversion to general anesthesia

All cases performed under peripheral nerve blocks as the primary anesthetic

Four cases of readmission in patients BMI 40-49:

No readmission in the BMI≥50 case

Obesity alone should not be a disqualification from ambulatory surgical centers

BMI alone, even as high as ≥50, may not be as important an exclusion criterion for ambulatory surgical centers, especially for surgery performed under regional anesthesia.