DIPHENHYDRAMINE AS ADJUNCTIVE THERAPY DURING MODERATE SEDATION FOR ENDOBRONCHIAL ULTRASOUND

Abstract

SESSION TITLE: Procedures Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: Endobronchial ultrasound (EBUS) and real-time guidance of transbronchial needle aspiration (TBNA) has become a widely adopted tool in evaluation of intrathoracic lymphadenopathy for malignant or non-malignant disease. EBUS has been shown to have comparable diagnostic yield and safety profile when done with either moderate sedation (MS) or deep sedation (DS). The purpose of this study was to assess the use of diphenhydramine in bronchoscopies and specifically EBUS/TBNA. METHODS: Patient data was collected via chart review of all bronchoscopies done at the Kansas City VA Medical Center between July 2018 and June 2019. Only procedures done under MS were included. Sedation medications used were fentanyl and midazolam. The use of intravenous diphenhydramine, dose and timing was at the discretion of the proceduralist. RESULTS: A total of 165 bronchoscopies were performed under MS; 84 were EBUS procedures. Of the EBUS patients, 81 (96.4%) patients were male; mean age was 66.4±10.7. No patients had a documented history of chronic opioid use.Midazolam and fentanyl were used for induction and maintenance of sedation in all EBUS patients. The mean doses were 5.3±3.3 mg of midazolam and 203.9±52.1 mcg of fentanyl. Diphenhydramine was used in 62 (73.8%) of EBUS procedures. Twenty (32.3%) patients received diphenhydramine at induction compared to 42 (67.7%) who only received it during the procedure. The mean dose of diphenhydramine was 41.5±12.7 mg.Comparing EBUS in which any diphenhydramine was used to cases in which it was not, there was no significant difference in the cumulative doses of midazolam (5.6±3.5 vs. 4.5±2.5mg, p=0.161) and fentanyl (204.8±57.6 vs. 201.1±33.2mcg, p= 0.777). The time to adequate sedation was significantly higher in patients who received diphenhydramine (11.1±4.9 vs. 8.6±2.9 min, p=0.006). Procedure time (64.0±25.1 vs 61.4±20.2 min, p=0.660) and recovery time (81.4±32.4 vs. 81.3±47.9 min, p=0.995) were not significantly different.Compared to no use at all, any diphenhydramine use (at induction or during the procedure) was associated with a lower fentanyl dose per minute (4.2±2.6 vs. 7.2±5.0 mcg/min, p<0.001) and a trend towards a lower midazolam dose per minute although not statistically significant (0.1±0.1 vs. 0.2±0.6 mg/min, p=0.271). CONCLUSIONS: Use of diphenhydramine in our cohort was associated with a mean of 3.0 mcg/min lower fentanyl dose, equivalent to an average fentanyl dose reduction of 193mcg per procedure. Further randomized controlled trials with a protocol for sedation including diphenhydramine or placebo would be the next endeavor to fully evaluate this hypothesis. CLINICAL IMPLICATIONS: Diphenhydramine appears to reduce fentanyl requirements and therefore should be considered as adjuctive therapy for moderate sedation in EBUS procedures. DISCLOSURES: No relevant relationships by Abdallah Abboud, source=Web Response No relevant relationships by Sonia Castillo, source=Web Response