Incidence and Risk Factors of Orthostatic Hypotension and Postural Tachycardia Following Sedated Colonoscopy: A Prospective Observational Study

<b>Background/Objectives</b>: Colonoscopy, a common outpatient procedure requiring bowel preparation, can lead to dehydration and electrolyte disturbances. Sedation, while improving patient comfort, may exacerbate these effects and contribute to orthostatic hypotension (OH) and postural orthostatic tachycardia syndrome (POTS). This study aimed to determine the prevalence of OH and POTS following sedated colonoscopy and to identify associated risk factors. <b>Methods</b>: This prospective observational study included 76 adult patients (ASA I-III) who underwent colonoscopy with fentanyl-propofol sedation between August and November 2024. Blood pressure, heart rate, and orthostatic intolerance (OI) symptoms were assessed before and after mobilization. OH was defined as a systolic blood pressure decrease ≥20 mmHg or diastolic decrease ≥10 mmHg upon standing. POTS was defined as a heart rate increase ≥30 bpm or an absolute heart rate ≥ 120 bpm. Statistical analyses were performed using SPSS 29.0. <b>Results</b>: Post-procedural OH and/or POTS occurred in 18 patients (23.7%), and 14 patients (18.4%) reported OI symptoms such as dizziness, nausea, or blurred vision. Symptomatic patients were significantly younger than asymptomatic patients (42.7 ± 15.4 vs. 54 ± 13.9 years, <i>p</i> = 0.009), and symptoms were more frequent among females (<i>p</i> = 0.046). Preoperative diastolic blood pressure was significantly higher in patients who developed OH (<i>p</i> = 0.022), while other hemodynamic and demographic variables showed no significant associations. <b>Conclusions</b>: Orthostatic hypotension and postural tachycardia are relatively common after sedated colonoscopy. Younger age and female sex were identified as independent risk factors for OI symptoms, suggesting a possible role of autonomic variability. Routine post-procedure monitoring and assisted mobilization before discharge may improve patient safety and recovery outcomes.