Safely Discharging Patients After Colonoscopy: An Evaluation of the Modified Aldrete Score

Bradley Evans, BSc, Hons, MD1, M Borgaonkar, MD, FRCPC1, D Pace, MD, FRCSC1, N Hickey, BSc, MD2, J McGrath, MD, FRCPC1. 1Memorial University of Newfoundland, 2Dalhousie University

Purpose: To investigate safety of the modified Aldrete scoring system as a tool to evaluate readiness for discharge after colonoscopy.

Methods: This retrospective cohort study was performed on adults who underwent colonoscopy in the city of St. John’s, Canada, in the year 2012. Subjects were identified through records from the health authority. Data were extracted from the electronic medical record, including both the endoscopist and nursing procedure reports. Data were recorded on a standardized data sheet and entered into SPSS version 20.0 for analysis. Modified Aldrete score upon discharge was recorded by endoscopy nursing staff. A score ≥9 was considered safe for discharge. Type and amount of sedation was recorded during the procedure. Perioperative adverse events occurred before discharge from the endoscopy unit and included; hypotension (<90/50 or <20% baseline), hypoxia (SpO2<85%), allergy, use of reversal agents, or need for CPR. Late adverse events were recorded within 14 days of discharge and included; transfer to emergency room, unplanned hospitalization or unplanned contact with health professional.

Results: Data were collected on 3235 colonoscopy procedures. Mean patient age was 58.4 years with 55.8% of the group being female. Most patients (97.1%) were outpatients and were ASA class 1 or 2 (73.5%). Asymptomatic screening or surveillance was the most common indication (61.3%). The majority of patients received some form of sedation (98.1%). The most commonly used sedatives were fentanyl (mean dose 94.22mcg) and versed (mean dose 3.09mg). Aldrete score at discharge was recorded for 2515 patients and of those, 98.9% had a score ≥9 on discharge.

Hypotension and hypoxia occurred in 15.4% and 9.9% of patients, respectively. Reversal agents were used in 4 patients to treat hypoxia and hypotension. There were 4 deaths recorded within 30 days of the procedure, none of which were felt to be sedation related. Late sedation related adverse events occurred in 10 patients. 9 of the 10 patients had an Aldrete score ≥9 and 1 was not recorded. Possible late sedation related adverse events included; 2 patients with non-cardiac chest pain, 3 patients with benign abdominal pain, 2 falls, 1 patient with syncope and sinus bradycardia, 1 pneumonia, and 1 patient with decreased level of consciousness.

Conclusion: Patients discharged with a modified Aldrete score of 9 or 10 had a 0.3% incidence of delayed adverse events that were possibly sedation related. This validates the practice of using a modified Aldrete score of 9 or 10 to determine safe discharge post colonoscopy.

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