Use of Ketamine for Conscious Sedation in Flexible Bronchoscopy: A Feasibility Study

Background: Ketamine has both analgesic and sedative properties, combined with favorable hemodynamic effects, which makes it a theoretically ideal agent for bronchoscopic sedation. Studies in the adult population that demonstrate safety, efficacy, and patient/physician satisfaction are lacking. We hypothesized that ketamine is an effective alternative to standard moderate sedation (SMS) regimens used for bronchoscopic sedation and may be preferred by patients and physicians. Research Question: Is ketamine an effective alternative to SMS for flexible fiberoptic bronchoscopy? Study Design and Methods: A randomized controlled trial was conducted comparing ketamine to SMS using midazolam and fentanyl for outpatient flexible fiberoptic bronchoscopy from July 2019 to March 2022. Patients who met inclusion criteria were randomized to receive either ketamine or SMS for bronchoscopic sedation. This was a single-anonymized study and the primary outcome was patient satisfaction based on the Patient Satisfaction with Sedation Instrument. Results: A total of 56 patients were enrolled with 28 randomized to each cohort. There was a significant increase in reported sedation side effects based on the Patient Satisfaction with Sedation Instrument (21.8 [SD 9.1] vs 17.0 [SD 5.6], P = .02) in the ketamine vs SMS cohorts respectively; however, global satisfaction was similar (5.4 [SD 4.6] vs 4.6 [SD 1.5], P = .38). Physician global satisfaction based on the Clinician Satisfaction with Sedation Instrument was significantly worse in the ketamine cohort (50.9 [SD 23.2] vs 35.0 [SD 10.8], P = .002), with significantly worse satisfaction scores in the sedation administration subset (26.7 [SD 12.5] vs 17.2 [SD 5.0], P ≤ .001) and secretions produced category (2.97 [SD 1.8] vs 1.93 [SD 1.6], P = .02). There were no significant differences in adverse events, and all procedures were completed successfully. Interpretation: Our results indicate that ketamine is safe in adult patients undergoing flexible fiberoptic bronchoscopy. However, the use of ketamine was associated with increased patient-reported side effects and decreased physician satisfaction. Clinical Trial Registration: ClinicalTrials.gov; No.: NCT06181188; URL: www.clinicaltrials.gov