Author: Lucas Silva (@lucasojesilva12)

In the last few years, the use of apneic oxygenation has been recommended by experts for management of high-risk airway situations, including emergency intubations in the ED (1), and for patients at risk for difficult laryngoscopy and intubation in the operating room (2).

The relative simplicity and safety of this intervention and the potential to turn intubation in a safer procedure, with higher success rates and fewer complications, led to a rapid and widespread use of the concept and to its even being considered by some as standard of care despite relatively scarce evidence to support its use (1). Recently, ICU-based studies have shown conflicting results on the effectiveness of apneic oxygenation using different approaches (3-8).

To evaluate the current evidence, we performed a systematic review and meta-analysis on the use of apneic oxygenation during emergency intubation (ED or ICU intubations), looking at outcomes as hypoxemia, first-pass success, and lowest oxygen saturation.  

Here the link to the paper (open access!):

http://www.annemergmed.com/article/S0196-0644(17)30582-6/fulltext

After a comprehensive literature search, including 4 large databases, we found 1,386 studies for review. After screening the titles and abstracts and removing duplicates, we identified 77 potentially relevant studies. After full-text review, a total of 14 studies met the inclusion criteria: 6 ICU studies, 6 ED studies, and 2 mixed ED and ICU studies. The included studies involved 2,023 participants, with 1,168 patients receiving apneic oxygenation during intubation and 855 not receiving it. Eight studies including 982 patients receiving apneic oxygenation and 855 not receiving it, underwent meta-analysis.

In this study, we found that the use of apneic oxygenation during emergency intubation appears to be associated with increased peri-intubation oxygen saturation and first-pass success rates, as well as decreased incidence of hypoxemia in patients intubated in the ED or ICU. The use of apneic oxygenation was associated with a decrease in ICU length of stay, but there was no difference in duration of mechanical ventilation and ICU mortality. We found no reports of adverse events related to the use of apneic oxygenation, despite different approaches and settings.

Main findings:

• Hypoxemia (SpO2 < 93%)
• • Meta-analysis of 8 studies, 1837 patients;
  • Odds ratio (OR) 0.66; 95% confidence interval (CI) 0.52 to 0.84.
• First-Pass Success (success on the first attempt of laryngoscopy)
• • Meta-analysis of 6 studies, 1658 patients;
  • OR 1.59; 95% CI 1.04 to 2.44.
• Lowest Oxygen Saturation Peri-Intubation
• • Meta-analysis of 6 studies, 1043 patients;
  • Weighted Mean Difference +2.2%; 95% CI 0.8% to 3.6%.

Limitations regarding our study, however, have to be acknowledged. The major limitation relates to the quality of included studies, which warrants a moderate to low level of certainty in the estimates. Another important limitation is the different approaches used to apneic oxygenation in terms of preoxygenation and other peri-intubation variables and co-interventions. The different methods of preoxygenation between groups could affect the likelihood of developing hypoxemia during the apneic period; therefore, the effect of apneic oxygenation was not isolated in some of the included studies. The maintenance of airway patency during apneic oxygenation was not described in most of the studies, and that might affect the quality of this intervention. The clinical heterogeneity of patients intubated in the ED and ICU in regard to their cardiorespiratory baseline status is also an important factor to be considered, and which approach is better among the spectrum of sickness in patients requiring emergency intubation still has to be evaluated by future studies.

In summary, in our meta-analysis apneic oxygenation was associated with increased peri-intubation SpO2, decreased hypoxemia, and increased first-pass intubation success.

Bottom-line: The current body of evidence supports the role of apneic oxygenation as an important adjunct for emergency airway management.

FULL-ARTICLE: (open access)

REFERENCES

1. Weingart SD, Levitan RM. Preoxygenation and prevention of desaturation during emergency airway management. Ann Emerg Med. 2012;59:165-175.e161.
2. Berkow L, Hagberg CA, Crowley M. Airway management for induction of general anesthesia. In: Post TWU, Waltham MA, eds. UpToDate.
3. Besnier E, Guernon K, Bubenheim M, et al. Pre-oxygenation with high-flow nasal cannula oxygen therapy and non-invasive ventilation for intubation in the intensive care unit. Intensive Care Med. 2016;42:1291-1292.
4. Jaber S, Monnin M, Girard M, et al. Apnoeic oxygenation via high-flow nasal cannula oxygen combined with non-invasive ventilation preoxygenation for intubation in hypoxaemic patients in the intensive care unit: the single-centre, blinded, randomised controlled OPTINIV trial. Intensive Care Med. 2016;42:1877-1887.
5. Miguel-Montanes R, Hajage D, Messika J, et al. Use of high-flow nasal cannula oxygen therapy to prevent desaturation during tracheal intubation of intensive care patients with mild-to-moderate hypoxemia. Crit Care Med. 2015;43:574-583.
6. Semler MW, Janz DR, Lentz RJ, et al. Randomized trial of apneic oxygenation during endotracheal intubation of the critically ill. Am J Respir Crit Care Med. 2016;193:273-280.
7. Simon M, Wachs C, Braune S, et al. High-flow nasal cannula versus bag-valve-mask for preoxygenation before intubation in subjects with hypoxemic respiratory failure. Respir Care. 2016;61:1160-1167.
8. Vourc’h M, Asfar P, Volteau C, et al. High-flow nasal cannula oxygen during endotracheal intubation in hypoxemic patients: a randomized controlled clinical trial. Intensive Care Med. 2015;41:1538-1548.

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