With the growing elderly population, ensuring the safety of non-anesthesiologist–administered propofol (NAAP) for colonoscopy is increasingly important; however, real-world data in older adults remain limited. This study aimed to identify independent predictors of adverse events and delayed recovery during NAAP-sedated outpatient colonoscopy, particularly in patients aged ≥75 years.

This retrospective study evaluated 20,041 consecutive outpatients who underwent colonoscopy with propofol sedation administered exclusively by non-anesthesiologist endoscopists between December 2015 and March 2024. Patients were stratified into three age groups (<50, 50–74, and ≥75 years). Adverse events included hypoxemia (SpO₂ <90%), hypotension (sBP <80 mmHg), bradycardia (HR <50/min), and delayed recovery, defined as a resting time exceeding 32 minutes. Multivariable logistic regression was performed using age, sex, BMI, cardiovascular disease, procedure duration, and propofol dose as covariates.

A total of 20,041 colonoscopies were included (4,766 <50 years; 11,449 aged 50–74; 3,826 aged ≥75). Adverse events increased with age, with hypoxemia, hypotension, and bradycardia occurring most frequently in patients aged ≥75 years (6.2%, 2.6%, and 2.8%, respectively; all p<0.01).

In multivariable analysis of the entire cohort, hypoxemia was independently associated with age (OR 1.03 per 1-year increase), BMI (OR 1.12 per 1 kg/m² increase), and procedure duration (OR 1.02 per 1-minute increase). Hypotension was independently associated with age (OR 1.05 per 1-year increase) and procedure duration (OR 1.03 per 1-minute increase). Bradycardia was associated with lower BMI (OR 0.93 per 1 kg/m²), cardiovascular disease (OR 2.47), and procedure duration (OR 1.02 per 1-minute increase). Delayed recovery was associated with cardiovascular disease (OR 1.13).

Despite increasing adverse event rates with age, mean recovery time did not differ significantly among the three age groups (26.8, 26.6, and 26.1 minutes; p=0.909).

Among patients aged ≥75 years, hypoxemia was independently associated with higher BMI and longer procedure duration (OR 1.10 per 1 kg/m², 95% CI 1.07–1.14; and OR 1.02 per minute, 95% CI 1.01–1.03, respectively). Bradycardia was associated with cardiovascular disease, female sex, and procedure duration (OR 2.72, 95% CI 1.95–3.79; OR 1.66, 95% CI 1.02–2.72; and OR 1.02 per minute, 95% CI 1.01–1.04). Hypotension was associated with cardiovascular disease and procedure duration (OR 1.60, 95% CI 1.03–2.48; and OR 1.03 per minute, 95% CI 1.00–1.06). No independent predictors of delayed recovery were identified in this age stratum.

In NAAP-sedated colonoscopy, advancing age contributed to an increased risk of cardiopulmonary events; however, physiological and procedural factors—including BMI, cardiovascular disease, sex, and procedure duration—also played important roles in determining overall vulnerability. Despite higher event rates in older adults, patients aged ≥75 years demonstrated recovery times comparable to those of younger individuals. These findings highlight the need to assess sedation risk comprehensively, incorporating both age and patient-specific physiological factors, and to apply individualized dosing and monitoring strategies to optimize the safety of NAAP in aging populations.