Preventing Hypoxia in Pediatric MRI Sedation: A Randomized Controlled Trial of Prophylactic Nasopharyngeal Airway Placement

TL;DR

Using a nasal airway during sedation for MRI in children reduces the risk of low oxygen levels and improves recovery time.

Contribution

This study is the first to show that placing a nasopharyngeal airway before sedation reduces hypoxia in children undergoing MRI.

Findings

Prophylactic NPA placement reduced hypoxia incidence from 11.5% to 4.6%.

Children with NPA had faster recovery times and similar propofol requirements.

MRI image quality was slightly better with NPA, though not statistically significant.

Abstract

Background: Deep procedural sedation for magnetic resonance imaging (MRI) is associated with airway collapse, causing hypoxia. The nasopharyngeal airway (NPA) is a simple rescue device, but there is limited literature on its prophylactic use to prevent hypoxia. This study evaluates the incidence of hypoxic episodes with and without prophylactic NPA placement in children undergoing MRI under sedation.

Methods: Two hundred and sixty-two American Society of Anesthesiologists (ASA) I and II children aged 1-10 years scheduled for MRI under sedation were randomized into the NPA and control groups. Both groups received intravenous midazolam, propofol bolus, and oxygen via a pediatric face mask. The NPA group had the airway placed, and sedation was maintained with propofol infusion. Hemodynamic, respiratory, and oxygen saturation parameters were monitored. Recovery time, discharge time, MRI quality, and adverse events were recorded.

Results: The NPA group showed a lower incidence of hypoxia (11.5% vs. 4.6%; P = 0.041) and faster recovery profile (5 (3.0, 6.0) vs. 5 (5.0, 7.0) minutes, P = 0.002). Propofol requirements (5 (3.6, 6.2) vs. 5 (4.1, 6.1) mg/kg, P = 0.539) and MRI duration (30 (25, 35 minutes) vs. 30 (25, 35 minutes), P = 0.226) were similar between groups. No major adverse events (epistaxis and laryngospasm) occurred in the NPA group. MRI quality was slightly better in the NPA group, though not statistically significant (P = 0.082).

Conclusion: Prophylactic NPA placement during propofol sedation for pediatric MRI reduces hypoxia, improves image quality, and minimizes interruptions. Sizing by nares-to-epiglottis distance ensures airway patency at multiple levels and, combined with capnography and oximetry, enhances the safety of deep sedation.

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