Buccal O2 in obese patients – 12.5 min of apnea

October 24, 2016

Short Attention Span Summary

12.5 minutes of normal SpO2 and apnea in obese patients!
This is a very exciting RCT.  They took a modified 3.5mm oral RAE tube (designed to make a sharp bend without kinking) and put it in the mouth, along the buccal mucosa at 10 L/min while lifting the tongue with a laryngoscope to a grade III equivalent view.  The 20 who got buccal O2 were much more likely than the 20 who did not to have 12.5 minutes of apnea without desaturation to <95% (Hazard ratio 0.159).  Median apnea time in the buccal O2 group was 750 seconds (12.5 minutes) vs. 296 seconds (~5 minutes) in the standard group.

Spoon Feed
Delivery of high flow buccal O2 is an easy, affordable way to make ETT placements in obese patients safer by prolonging apnea times without desaturation.  This article is one I highly recommend you find full text and read the methods.  This really works!

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        <div class="image-caption">MD Calc has a free app! It's amazing! And if you download it through October, they donate to the Breast Cancer Research Foundation.</p></div>
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Abstract

Anesth Analg. 2016 Sep 20. [Epub ahead of print]

Apneic Oxygenation During Prolonged Laryngoscopy in Obese Patients: A Randomized, Controlled Trial of Buccal RAE Tube Oxygen Administration.

Heard A1, Toner AJ, Evans JR, Palacios AM, Lauer S.

Author information: 

• 1From the *Department of Anaesthesia and Pain Medicine, Royal Perth Hospital, Perth, Australia; †Department of Anaesthesia, Fremantle Hospital, Perth, Australia; and ‡Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, Germany.

ABSTRACT

BACKGROUND: 

Despite optimal preoxygenation, obese patients undergoing induction of general anesthesia exhibit significant hypoxemia after 2 to 4 minutes of apnea. Apneic oxygenation techniques can assist airway management by extending the safe apnea time. We hypothesized that a novel method of apneic oxygenation via the oral route would effectively prolong safe apnea in an obese surgical population.

METHODS: 

In this open-label, parallel-arm, randomized-controlled efficacy trial, 40 ASA physical status I-II obese patients with body mass index (BMI) 30-40 were randomly assigned to standard care (n = 20) or buccal oxygenation (n = 20) during induction of total IV anesthesia. Buccal oxygen was administered via a modified 3.5-mm Ring-Adair-Elwyn (RAE) tube apposed to the left internal cheek. Prolonged laryngoscopy maintained apnea with a patent airway until SpO2 dropped below 95% or 750 seconds elapsed. The primary outcome was time to reach SpO2 < 95%.

RESULTS: 

Patient characteristics were similar in both study arms. Recipients of buccal oxygenation were less likely to exhibit SpO2 < 95% during 750 seconds of apnea; hazard ratio 0.159 (95% confidence interval 0.044-0.226, P < .0001). Median (interquartile range [IQR]) apnea times with SpO2 ≥ 95% were prolonged in this group; 750 (389-750) versus 296 (244-314) seconds, P < .0001.

CONCLUSIONS: 

Clinically important prolongation of safe apnea times can be achieved delivering buccal oxygen to obese patients on induction of anesthesia. This novel use of apneic oxygenation via the oral route may improve management of the difficult airway and overcome some of the limitations of alternative techniques.

PMID: 27655276 [PubMed – as supplied by publisher]