Respiratory support with nasal high flow without supplemental oxygen in patients undergoing endoscopic retrograde cholangiopancreatography under moderate sedation: a prospective, randomized, single-center clinical trial

Abstract

BACKGROUND: Nasal high flow (NHF) may reduce hypoxia and hypercapnia during an endoscopic retrograde cholangiopancreatography (ERCP) procedure under sedation. The authors tested a hypothesis that NHF with room air during ERCP may prevent intraoperative hypercapnia and hypoxemia. METHODS: In the prospective, open-label, single-center, clinical trial, 75 patients undergoing ERCP performed with moderate sedation were randomized to receive NHF with room air (40 to 60 L/min, n = 37) or low-flow O2 via a nasal cannula (1 to 2 L/min, n = 38) during the procedure. Transcutaneous CO2, peripheral arterial O2 saturation, a dose of administered sedative and analgesics were measured. RESULTS: The primary outcome was the mean time-weighted total PtcCO2 of 47.2 mmHg in the NHF group and 48.2 mmHg in the LFO group, with no significant difference (-0.97, 95% CI -3.35 – 1.41, p = 0.421). In secondary outcome analysis, the duration of hypercapnia did not differ markedly between the two groups either [median (range) in the NHF group: 7 (0 – 99); median (range) in the LFO group: 14.5 (0 – 206); p = 0.313] and the occurrence of hypoxemia during an ERCP procedure under sedation was observed in 3 patients (8.1%) in the NHF group and 2 patients (5.3%) in the LFO group, with no significant difference (p = 0.674). CONCLUSIONS: Application of NHF with air did not reduce marked hypercapnia during ERCP under sedation relative to LFO. However, there was no significant difference in occurrence of hypoxemia between the two groups that indicates an improvement of gas exchanges by NHF. Trial registration jRCTs072190021 (https://jrct.niph.go.jp/en-latest-detail/jRCTs072190021) The full date of first registration on jRCT: 26/08/2019

Examination of stabilization of sedation by Nasal High Flow in patients with endoscopic retrograde cholangiopancreatography during sedation using Dexmedetomidine

“…[18] Zhang YX et al [19] also indicated that efficacy of NHF not only to reduce the incidence of hypoxemia but also reduce the requirements for airway intervention during sedated digestive endoscopy procedures, especially in patients at low risk for hypoxemia. Furthermore, we have recently suggested that the application of NHF did not result in a significant reduction in the occurrence of marked hypercapnia during an ERCP procedure with www.md-journal.com [14] Therefore, this randomized clinical trial might obtain new insight to evaluate the efficacy of NHF on respiratory management. Schumann et al reported that the availability to use NHF during sedation in an endoscopy suite reduced the requirement for general anesthesia to perform complex endoscopic procedures.…”

“…Furthermore, we have recently suggested that the application of NHF did not result in a significant reduction in the occurrence of marked hypercapnia during an ERCP procedure with sedation. [14] Therefore, this randomized clinical trial might obtain new insight to evaluate the efficacy of NHF on respiratory management. Schumann et al reported that the availability to use NHF during sedation in an endoscopy suite reduced the requirement for general anesthesia to perform complex endoscopic procedures.…”

“…From an exploratory study conducted in advance, the average total dose of pethidine hydrochloride in the NHF-using group and the low flow oxygen group was 2.774 units and 3.933 units, respectively. [14] From this, it was hypothesized that the total unit of administration of pethidine hydrochloride follows a Poisson distribution with exp (1.02) = 2.774 in the NHF-using group and exp (1.37) = 3.933 in the non-NHF use group. Simulations were performed using a Poisson regression model with the objective variable as the total dose unit of pethidine hydrochloride and the explanatory variables as the group.…”

“…Interesting findings have been obtained that the total dose of the concomitant analgesic (pethidine hydrochloride) tend to be reduced to obtain the same sedation. [13,14] In this study, we applied NHF as a respiratory management method to patients undergoing ERCP under sedation to prevent the onset of intraoperative hypercapnia and reduce the respiratory workload during sedation. The purpose is to examine whether sedation can be stabilized by reducing the arousal response.…”

“…Interesting findings have been obtained that the total dose of the concomitant analgesic (pethidine hydrochloride) tend to be reduced to obtain the same sedation. [13,14]…”