Conflict of Interest Declaration
The ILCOR Continuous Evidence Evaluation process is guided by a rigorous ILCOR Conflict of Interest policy. The following Task Force members and other authors were recused from the discussion as they declared a conflict of interest: None
The following Task Force members and other authors declared an intellectual conflict of interest and this was acknowledged and managed by the Task Force Chairs and Conflict of Interest committees: None
Task Force Scoping Review Citation
Bierens J, Barcala Furelos R, Beerman S, Claesson A, Dunn C, Elsenga H, Gomez CA, Morgan P, Bierens J, Barcala-Furelos R, Beerman S, Claesson A, Dunne C, Elsenga H, Abelairas-Gomez C, Morgan P, Mecrow T, Pereira JCC, Scapigliati A, Seesink J, Schmidt A, Sempsrott J, Szpliman D, Warner DS, Webber J, Johnson S, Avis S, Mancini MB, Nation K, Brooks S, Castren M, Chung S, Considine J, Kudenchuk P, Nishiyama C, Ristagno G, Semeraro F, Smyth M, Vaillancourt C, Olasveengen T, Morley P, Perkins GD on behalf of the International Liaison Committee on Resuscitation Basic Life Support Task Force(s).
Prehospital Oxygen in Drowning. Review and Task Force Insights [Internet] Brussels, Belgium: International Liaison Committee on Resuscitation (ILCOR) Basic Life Support Task Force, 7 July 2020. Available from: http://ilcor.org
Methodological Preamble and Link to Published Scoping Review
The continuous evidence evaluation process started with a scoping review of the literatures undertaken by David Warner and Joost Bierens and co-ordinated by Gavin Perkins and Joost Bierens. The findings from the review of basic life support were considered by the Basic Life Support Task Force who contributed to the Task Force insights.
Webmaster to insert the Scoping Review citation and link to Pubmed using this format when/if it is available.
The PICOST (Population, Intervention, Comparator, Outcome, Study Designs and Timeframe)
Population: In adults and children who are submerged in water
Intervention: pre-hospital oxygen administration
Comparators: no pre-hospital oxygen administration
Outcomes: Any clinical outcome (e.g. survival, survival with a favourable neurological outcome, hospitilisation), CPR quality, physiological end-points
Study Designs: Randomized controlled trials (RCTs) and non-randomized studies (non-randomized controlled trials, interrupted time series, controlled before-and-after studies, cohort studies) are eligible for inclusion. Manikin studies will only be included if no human studies are available.
Timeframe: From 2000 onwards. All languages were included as long as there was an English abstract; unpublished studies (e.g., conference abstracts, trial protocols), narrative reviews, animal studies were excluded. Literature search updated to October 2019.
Inclusion and Exclusion criteria
- Adult and paediatric patients
- Submersion in water (drowning, near drowning)
- Describe use of pre-hospital oxygen
- Studies report clinical outcomes e.g. survival, survival with a favourable neurological outcome, hospitilisation
- Other outcomes: CPR quality, physiology
- Animal studies
- Results reported in the gray literature or abstract only
- Narrative reviews containing no primary data
- Published as an abstract only or in conference proceedings.
- Case studies / series without control groups, unless no or minimal other literature available.
Task Force Insights
1. Why this topic was reviewed.
Drowning is the third leading cause of unintentional injury death worldwide, accounting for over 360 000 deaths annually.[World Health Organization, 2020] Submersion in water leads to the rapid onset of hypoxia. Left untreated cardiac arrest occurs within minutes. The use of pre-hospital oxygen has the potential to reverse hypoxaemia and may improve outcomes. However providing access to oxygen therapy has substantial resource implications to cover the costs of equipment and training. In addition, without access to pulse oximetry and / or arterial blood gas analysis, identifying patients who may benefit from oxygen therapy can be difficult. Finally, some studies suggest, sustained hyperoxia may cause harm. The BLS Task Force and Drowning collaboration considered it timely to undertake a scoping review of the literature to identify any new evidence related to this topic.
2. Narrative summary of evidence identified
The literature search identified 3005 articles (2190 after removal of duplicates). After screening titles and abstracts, 23 studies were identified for full text review. Of these, three studies evaluated pre-hospital oxygen use.
A single retrospective observational study reported the outcomes of adults and No studies were identified which specifically examined the pre-hospital use of oxygen in adults or children who had sustained a submersion incident.
In-direct evidence from observational studies found associations between hypoxia, oxygen administration and worse outcomes.
Cantu et al showed a higher rate of hospital admission in patients with an initial SpO2 <95 on arrival in the emergency department (92% versus 52%, aOR 6.8 (1.07 to 43.8).[Cantu, 2018, 446] Hospital admission rates were also higher (91% versus 34%) amongst 71 children with an initial SpO2 <92 at the scene or on arrival in the emergency department in univariate but not multivariate analysis.[Cohen, 2019, 1379] By contrast Gregorakos et al did not find an association between PaO2 : FiO2 ratio and the duration of hospital stay amongst 43 adults and children.[Gregorakos, 2009, 93]
In an observational study involving 31 adults lower oxygen saturations (87%(13.4) versus 76,0(7.94) P=0.007) and PaO2 : FiO2 ratio (255(83.5) versus 133 (58.3) P=0.004) were associated with reduced survival with a favourable neurological outcome. [Jung, 2003, 287]
3. Narrative Reporting of the task force discussions
A limited evidence base was identified in this scoping review, but a systematic review on this topic will be required if a recommendation is intended to be made by the task force.
The review found insufficient specific evidence to guide the pre-hospital use of oxygen therapy in drowning. The primary cause of death from immersion is insufficient oxygen delivery to the heart and brain to maintain viability and thus prompt restoration of oxygen delivery is of paramount importance. This review also found evidence of lung injury associated with immersion and common need for continued supplemental oxygen in some patients. Work in other domains of resuscitation science have identified adverse outcomes associated with both sustained hypoxia and hyperoxia. Pulse oximetry can be unreliable particularly following cold water immersion,[Montenij, 2011, 1235] but where feasible, can allow continuous titration of FIO2 following restoration of spontaneous circulation.
In the absence of specific research in drowning, the existing ILCOR Treatment Recommendation for Oxygenation after ROSC applies. This guides to avoid hypoxaemia and hyperoxia, using 100% inspired oxygen until arterial oxygen saturation or the partial pressure of arterial oxygen can be measured. https://costr.ilcor.org/document/oxygen-and-carbon-dioxide-targets-in-adult-patients-with-return-of-spontaneous-circulation-after-cardiac-arrest-task-force-systematic-review-costr
Current knowledge gaps include but are not limited to:
Prospective observational and randomised trials evaluating the safety and effectiveness of pre-hospital oxygen therapy after drowning.
Use of oxygen with and without
Studies in low resource settings were lacking.
References listed alphabetically by first author last name in this citation format
Cantu, R. M., et al. (2018). "Predictors of emergency department discharge following pediatric drowning." American Journal of Emergency Medicine 36(3): 446.
Cohen, N., et al. (2019). "Predictors for hospital admission of asymptomatic to moderately symptomatic children after drowning." European Journal of Pediatrics 178(9): 1379.
Gregorakos, L., et al. (2009). "Near-drowning: clinical course of lung injury in adults." Lung 187(2): 93.
Jung, C. Y., et al. (2003). "Clinical Feature of Submersion Injury in Adults. [Korean]." Tuberculosis and Respiratory Diseases 55(3): 287.
Montenij, L. J., et al. (2011). "Feasibility of pulse oximetry in the initial prehospital management of victims of drowning: a preliminary study." Resuscitation 82(9): 1235.
World Health Organization (2020) Drowning.