The 2023 American Society of Anesthesiologists (ASA) Practice Guidelines emphasize the importance of using quantitative neuromuscular monitoring to ensure safe and effective management of neuromuscular blockade during general anesthesia. Clinical bedside tests, though commonly used, are not reliable indicators of adequate neuromuscular recovery. Quantitative monitoring has been linked to benefits such as more effectivereversal of blockade,shorter post-anesthesiacare unit (PACU) stays,and fewer postoperativepulmonary complications.Since the release of theseguidelines, increasedadoption of quantitativemonitoring has enabledevaluation of patient-specific factorscontributing to monitoring failure, prompting investigation into the impact of comorbidities.We hypothesize that patient comorbidities—specifically diabetes, neuropathy, and morbid obesity (BMI ≥ 40)—are associated with increased dysfunction in quantitative neuromuscular monitoring.

Design: Case-control study at a single University Medical Center (Jan 1–June 30, 2023) of surgical patients monitored with quantitative neuromuscular blockade monitors.

Cases (n=142): Patients with quantitative monitor dysfunction, defined as inaccurate or failed readings not caused by technical or procedural factors documented in EHR.

Controls (n=142): Randomly selected surgical patients from the same period without documented monitor dysfunction.

Exclusions: Surgeries without neuromuscular blockade; monitor dysfunction attributed to electrode dislodgement, surgical interference, or procedural requirements.

Exposures of interest: Documented preoperative diabetes (any type), neuropathy (any type), and morbid obesity (BMI ≥40).

The presence of any of the three risk factors—diabetes, neuropathy, or morbid obesity—was significantly associated with increased odds of monitor dysfunction (OR 3.20; 95% CI: 1.97–5.20). Individually, diabetes (OR 2.94; 95% CI: 1.75–4.93) and neuropathy (OR 3.26; 95% CI: 1.90–5.60) were each independently significantly associated with dysfunction. Morbid obesity was not significantly associated (OR 1.06; 95% CI: 0.54–2.09).