Lit of the Week – Preoxygenation

Weingart S, et al. “Preoxygenation and prevention of desaturation during emergency airway management.” Ann Emerg Med. 2012;59:165-175.

Clinical question / background:

·      Patients requiring emergency airway management are at great risk of hypoxemic hypoxia because of primary lung pathology, high metabolic demands, anemia, insufficient respiratory drive, and inability to protect their airway against aspiration. Tracheal intubation is often required before the complete information needed to assess the risk of periprocedural hypoxia is acquired. Desaturation to below SpO2 70% puts patients at risk of arrhythmia, hemodynamic decompensation, hypoxic brain injury and death. This paper reviews the research and makes recommendations for preoxygenation before intubation in the Emergency Department

Sequence of Preoxygenation and Prevention of Desaturation

Preoxygenation Period

·      Position the patient in a semi-recumbent position or in reverse Trendelenberg. Position the patient’s head in the ear-to-sternal-notch position using padding if necessary.

·      Place a nasal cannula in the patient’s nares. Do not hook the nasal cannula to oxygen regulator.

·      Place patient on a non-rebreather mask at the maximal flow allowed by the oxygen regulator (at least 15lpm, but many allow a much greater uncalibrated flow)

·      If patient is not saturating >90%, remove face mask and switch to non-invasive CPAP by using ventilator, non-invasive ventilation machine, commercial CPAP device, or BVM with PEEP valve attached. Titrate between 5-15cm H2O of PEEP to achieve an oxygen Saturday >98%. Consider this step in patients saturation 91-95%.

·      Allow patient to breath at tidal volume for 3 minutes or ask the patient to perform 8 maximal exhalations and inhalations.

Apneic Period

·      Push sedative and paralytic (Preferably rocuronium, if the patient is at risk for rapid desaturation)

·      Detach face mask from the oxygen regulator and attach the nasal cannula. Drop the flow rate to 15lpm.

·      Remove the face mask from the patient

·      Perform a jaw thrust to maintain pharyngeal patency

·      If the patient is high risk (required CPAP for preoxygenation), consider leaving on the CPAP during the apneic period or providing 4-6 ventilations with the BVM with a  PEEP valve attached. Maintain a two-hand mask seal during the entire apneic period to maintain the CPAP

Intubation Period

·      Leave the nasal cannula on throughout the management period to maintain apneic oxygenation

 

 

1 comments

    • James O'Shea on February 9, 2016 at 8:48 pm
    • Reply

    Great article and one we should all put into practice, further recent evidence below in support of same;

    First Pass Success without Hypoxemia is Increased with the Use of Apneic Oxygenation During RSI in the Emergency Department

    Sakles, J. et al 2016 Academic Emergency Medicine

    Abstract

    Objective: To determine the effect of apneic oxygenation (AP OX) on first pass success
    without hypoxemia (FPS-H) in adult patients undergoing rapid sequence intubation (RSI) in the emergency department (ED).

    Methods: Continuous quality improvement (CQI) data were prospectively collected on all patients intubated in an academic ED from July 1, 2013 to June 30, 2015. During this period the use of AP OX was introduced and encouraged for all patients undergoing RSI in the ED. Following each intubation, the operator completed a standardized data form which included information on patient, operator and intubation characteristics. Adult patients 18 years of age or greater who underwent RSI in the ED by emergency medicine residents were included in the analysis. The primary outcome was FPS-H, which was defined as successful tracheal intubation on a single laryngoscope insertion without oxygen saturation falling below 90%. A multivariate logistic regression analysis was performed to determine the effect of AP OX on FPS-H.

    Results: During the two-year study period, 635 patients met inclusion criteria. Of these, 380 (59.8%) had AP OX utilized and 255 (40.2%) had NO AP OX utilized. In the AP OX cohort the FPS-H was 312/380 (82.1%) and in the NO AP OX cohort the FPS-H was 176/255 (69.0%) (difference 13.1%; 95% CI 6.2% to 19.9%). In the multivariate logistic regression analysis, the use of AP OX was associated with an increased odds of FPS-H (adjusted OR 2.2; 95% CI: 1.5 to 3.3).

    Conclusion: The use of AP OX during the RSI of adult patients in the ED was associated with a significant increase in FPS-H. These results suggest that the use of AP OX has the potential to increase the safety of RSI in the ED by reducing the number of attempts and incidence of hypoxemia.

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