Pulse Oximetry Desaturation in the Postoperative Recovery Room in Patients with Obesity and Diabetes Using GLP-1...

Glucagon-like peptide-1 agonists (GLP-1), obesity, and diabetes may delay gastric emptying in some settings. We tested three hypotheses. First, the duration of GLP1-hold is associated with a larger difference between pulse oximetry at room air immediately preoperatively and one hour postoperatively, just prior to discharge home (DSpO2), as a marker of clinically important atelectasis and/or micro-aspiration. Second, we tested the hypothesis that the duration of GLP1-hold affects fasting glucose. Third, we tested the hypothesis that DSpO2 is linked to morbid obesity.

In this retrospective observational cohort study, we screened the cohort of all 1571 patients undergoing urologic ambulatory surgery in one stand-alone center between September 2023 and September 2024. The inclusion criteria were diabetics using GLP-1 within 30 days, creatinine below 2 mg/dL, and age between 18 and 80 years. The outcomes of fasting glucose and DSpO2 were compared between the groups holding GLP-1 longer and shorter than seven days. The outcome DSpO2 was also compared between the groups with and without morbid obesity, defined generally as a body mass index (BMI) of over 35 kg/m² in the presence of one major comorbidity. All of our study subjects had diabetes mellitus, a major comorbidity.

Among all 107 subjects, 56% had laryngeal mask airways and 9% endotracheal tubes. GLP-1 was held 12 ± 8 days (mean ± SD). DSpO2 was 1.5% ± 1.9 with short GLP-1-hold versus 1.8% ± 2.0 with long GLP-1-hold (p=0.41). The mean glucose was 130 mg/dL ± 49 with short GLP1-hold versus 138 mg/dL ± 39 with long GLP-1-hold (p=0.69). DSpO2 was 2.29% ± 1.78 with morbid obesity (N=38) versus 1.43% ± 1.99 without (N=69, p=0.0254, unpaired two-tailed t-test). Patients with morbid obesity showed a trend toward twice the incidence (at 24%) for DSpO2 > 4% (chi-square, p=0.14).

It may be prudent to protect the airway with endotracheal intubation for patients with morbid obesity and diabetes using GLP-1, especially in the lithotomy position.