Correspondence / American Journal of Emergency Medicine 36 (2018) 319-338

What’s the evidence for apnoeic oxygenation

335

Thomas Melhuish

during intubation? Who, where and when

Hypoxemia is one of the most significant complications that may arise during intubation. Several strategies have been proposed to curb this risk. A strategy of increasing interest in the literature is the use of apneic oxygen- ation during intubation. Recent reviews have attempted summarise this in- tervention as a whole [1,2]. These reviews have shown promising results with significant reductions in the incidence of desaturation (SpO₂ b 93%) and critical desaturation (SpO₂ b 80%). However, these results have been linked to high levels of heterogeneity. This is largely related to the highly heterogenous study populations and locations. The American Journal of Emergency Medicine has recently published reviews investigating this in- tervention in specific patient populations and situations [3,4]. Currently there are varying levels of evidence [5] in multiple patient populations, in- tubation locations and elective versus emergency intubation.

Currently there is level 2a evidence to support no significant reduc- tion in desaturation, critical desaturation or mortality in respiratory fail- ure patients [3]. There is level 1b evidence to support a reduction in the incidence of desaturation in obese and Paediatric populations [6,7]. Crit- ical desaturation and mortality did not occur in the study of these pa- tient populations. The use of apneic oxygenation is associated with significantly reduced desaturation and critical desaturation in patients intubated for intracranial haemorrhage (Level 2b evidence) [8].

Multiple studies have been performed in the retrieval setting, emer- gency department, intensive care unit and the operating theatre. In the setting of retrieval and the emergency department there is level 2a evi- dence to support a significant reduction in desaturation and critical desaturation, with no assessment of mortality [3]. In the intensive care unit there is level 1a evidence to support a significant reduction in desaturation and level 2a evidence for a significant reduction in critical desaturation [9]. In the intensive care population there is potentially a trend towards reduced mortality (RR = 0.77; 95%CI = 0.59 to 1.03; p

= 0.08; Level 1a evidence), however further studies are required to estab- lish whether this reduction is significant [9]. In the operating theatre and elective intubation, there is level 1a evidence for a significant reduction in desaturation [10]. Critical desaturation and mortality were not assessed in the operating theatre studies. Finally, there is level 2a evidence to support the use of apneic oxygenation to reduce the incidence of desaturation and critical desaturation during emergency intubation [4]. Similar to the ICU studies, there was a non-significant trend towards reduced mortality (RR = 0.078; 95%CI = 0.59 to 1.02; p N 0.05).

In summary, the use of apneic oxygenation during intubation shows significant benefit in the majority of patient populations, intubation lo- cations and situations. However, it is not a ‘silver bullet’ with no conclu- sive evidence to support a reduction in mortality. The one patient group where no benefit has been shown is patients with respiratory failure. Despite the lack of efficacy in this group, no adverse effects of apneic ox- ygenation have been shown. Therefore, it reasonable to recommend the routine use of apneic oxygenation during intubation.

Conflicts of interest

Nil.

Ruan Vlok

Wagga Wagga Rural referral hospital, Australia University of Notre Dame Australia, School of Medicine Sydney, Australia Corresponding author at:WaggaWagga Rural Referral

Hospital, Australia

E-mail address: [email protected].

Matthew Binks

Wagga Wagga Rural Referral Hospital, Australia

Wagga Wagga Rural Referral Hospital, Australia University of New South Wales, Faculty of Medicine, Australia

Rhys Holyoak

The Wollongong Hospital, Australia

Leigh White Caboolture Hospital, Caboolture, QLD, Australia University of Wollongong, NSW, Australia

18 July 2017

https://doi.org/10.1016/j.ajem.2017.07.074

References

1. Holyoak RS, Melhuish TM, Vlok R, Binks M, White LD. Intubation using apnoeic ox- ygenation to prevent desaturation: a systematic review and meta-analysis. J Crit Care 2017;41:42-8.
2. White LD, Melhuish TM, White LK, Wallace LA. Apnoeic oxygenation during in- tubation: a systematic review and meta-analysis. Anaesth Intensive Care 2017; 45(1).
3. Binks MJ, Holyoak RS, Melhuish TM, Vlok R, Bond E, White LD. Apneic oxygenation during intubation in the emergency department and during retrieval: a systematic review and meta-analysis. Am J Emerg Med 2017;35(10):1542-6.
4. Pavlov I, Medrano S, Weingart S. Apneic oxygenation reduces the incidence of hyp- oxemia during emergency intubation: A systematic review and meta-analysis. Am J Emerg Med 2017;35(8):1184-9.
5. Howick J, Chalmers I, Glasziou P, Greenhalgh T, Heneghan C, Liberati A, et al. The

   2011 Oxford CEBM levels of evidence (introductory document). Available at: http://www.cebm.net/index.aspx?o=5653; 2011.

   Ramachandran SK, Cosnowski A, Shanks A, Turner CR. Apneic oxygenation during prolonged laryngoscopy in obese patients: a randomized, controlled trial of nasal Oxygen administration. J Clin Anesth 2010;22(3):164-8.

6. Humphreys S, Lee-Archer P, Reyne G, Long D, Williams T, Schibler A. Transnasal hu- midified rapid-insufflation ventilatory exchange (THRIVE) in children: a random- ized controlled trial. Br J Anaesth 2017;118(2):232-8. https://doi.org/10.1093/bja/ aew401.
7. Sakles JC, Mosier JM, Patanwala AE, Dicken JM. Apneic oxygenation is associated with a reduction in the incidence of hypoxemia during the RSI of patients with intra- cranial hemorrhage in the emergency department. Intern Emerg Med 2016;11(7): 983-92.
8. Binks M, Holyoak R, Melhuish T, Vlok R, Hodge A, White L. Apnoeic oxygenation dur-

   ing intubation in the intensive care unit: A systematic review and meta-analysis. Heart Lung 2017 [in press].

   Melhuish T, Vlok R, Holyoak R, Binks M, White L. Apnoeic oxygenation during intu- bation in the operating theatre: a systematic review and meta-analysis. Brisbane, Australia: ANZCA ASM; 2017.

   Predictive factors of Negative appendectomy in children

   

   Dear Editor,

   Acute appendicitis is one of the most common pediatric surgi- cal conditions seen in children. The annual incidence of AA is 37.2 per 10,000 American children between the ages of 0-14 years [1]. The deci- sion to perform operation on a patient with suspected AA is based main- ly on disease history and physical findings and ultrasound findings [2]. However, the diagnosis of acute appendicitis in children is often chal- lenging. This may be related to the variable presentation and greater di- agnostic uncertainty in Younger children presenting with acute abdominal pain. Since Delayed diagnosis and treatment of AA are asso- ciated with increased length of stay, postoperative complications and mortality, Timely intervention is crucial [3-5]. Therefore, it is important to identify clinical predictive factors of appendicitis in order to reduce negative appendectomy rates. The aim of this study is to compare two