Background and study aims Sedation of high-risk patients is a relevant issue in interventional endoscopy. This is especially because standard oximetric monitors display only hypoxia and not the preceding hypercapnia. Therefore, the question arises whether use of a nasal positive airway pressure (nPAP) system can decrease the rate of sedation-associated events.

Patients and methods A randomized, prospective trial was conducted at University Hospital Ulm, including 98 consecutive patients, identified as high-risk (American Society of Anesthesiologists physical status ≥3) and scheduled for prolonged (>15 minutes) endoscopic procedures. Patients underwent 1:1 randomization to two groups: interventional (nPAP-Mask) and control (conventional oxygen supplementation). Levels of CO2 were measured noninvasively by transcutaneous capnometry device. The primary outcome was incidence of hypoxia (SpO2 <90% over 10 seconds) and incidence of severe hypoxia was incidence of SpO2 <80% over 10 seconds. One of our secondary objectives was to determine if the nPAP-Mask could result in significant CO2 retention among high-risk patients.

Results Data analysis showed lower incidence of hypoxia in the interventional group (10/47 vs. 31/251) P <0.05. Episodes of severe hypoxia (SpO2 <80% over 10 seconds) were more frequent in the control group (8/51) compared with the intervention group (2/47) P <0.05. There was no significant difference in ΔCO2 levels in the interventional vs. control group (–6.01±7.66 vs. –7.35±8.59 mm Hg).

Conclusions In high-risk patients use of a nasal positive airway pressure system could significantly lower risk of hypoxia, especially in prolonged procedures. The nPAP-Mask does not induce CO2 retention when compared with conventional oxygen supplementation.

Received: 10 October 2023

Accepted after revision: 12 April 2024

Accepted Manuscript online:
15 April 2024

Article published online:
29 May 2024

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