Use of Supplementary Oxygen in First Aid:FA 1549 TF ScR

Conflict of Interest Declaration

The ILCOR Continuous Evidence Evaluation process is guided by a rigorous ILCOR Conflict of Interest policy. The Task Force members report no conflicts of interest.

Task Force Synthesis Citation

Macneil F, Chang WT, Singletary EM, Djärv T on behalf of the International Liaison Committee on Resuscitation First Aid Task Force. Use of Supplementary Oxygen in First Aid. First Aid Task Force Synthesis of a Scoping Review. Brussels, Belgium: International Liaison Committee on Resuscitation (ILCOR) First Aid Task Force, 11 December, 2023. Available from: ILCOR.org

Methodological Preamble and Link to Published Scoping Review

The continuous evidence evaluation process started with a 2015 systematic review of the use of supplementary oxygen by first aid providers conducted by the ILCOR First Aid Task Force. As this topic has not been updated in the interim, a scoping review of the use of supplementary oxygen by first aid providers was conducted by the ILCOR First Aid Task Force Scoping Review team. Evidence for adult and pediatric literature was sought and considered by the First Aid Task Force. The task force noted the recent reviews of the use of supplementary oxygen following return of spontaneous circulation{Wyckroff 2022 e645}, suspected stroke{Singletary 2020 S284}, acute coronary syndrome{Nikolaou 2015 e121} and drowning {Bierens 2023 1}. Hence these topics were not considered in this review.

Scoping Review

Webmaster to insert the Scoping Review citation and link to Pubmed using this format when/if it is available.

PICOST

The PICOST (Population, Intervention, Comparator, Outcome, Study Designs and Timeframe)

Population: Adults and children who exhibit symptoms or signs of shortness of breath, difficulty breathing or hypoxia outside of a hospital

Intervention: Administration of oxygen by a first aid provider

Comparators: No administration of oxygen

Outcomes: Functional outcome at discharge, 30 days, 60 days, 180 days AND/OR 1 year, survival only at discharge, 30 days, 60 days, 180 days AND/OR 1 year, length of hospital stay, resolution of symptoms or signs, patient comfort, therapeutic endpoints (e.g., oxygenation, ventilation)

Study Designs: Randomized controlled trials (RCTs) and non-randomized studies (non-randomized controlled trials, interrupted time series, controlled before-and-after studies, cohort studies), case series and reports are eligible for inclusion. Only English language is included.

Timeframe: All dates to July 2023; search updated to December 1, 2023

Search Strategies: FA 1549 Supplementary Oxygen Search Strategies 2023

Inclusion and Exclusion criteria

Inclusion criteria

• Out of hospital

• Oxygen administered

• Carbon monoxide poisoning

• Diving using compressed gas

• Reviews

• Trial registers

Exclusion:

• Medical intervention

• Nursing intervention

• Paramedic intervention not excluded to extend scope

• Drowning

• ECMO/extracorporeal circulatory support

• Post return of spontaneous circulation

• Stroke

• Non-traumatic chest pain

• Duplicate report of trial

• Educational papers (not research)

• Audit

• Hypoxic training

• Epidemiology

PRISMA diagram:

FA 1549 Supplementary Oxygen PRISMA 10 Dec23

Data Table: FA 1549 Supplementary Oxygen Data Table 10 Dec23

Task Force Insights

1. Why this topic was reviewed.

• The ILCOR First Aid task force elected by consensus in 2023 to undertake a scoping review on the use of oxygen in first aid in 2023. The Task Force noted the systematic review in 2015 on the same question, with a search last conducted in November 2014, as well as a scoping review in 2022 with more exclusions than the current review. The Task Force wished to determine whether there have been publications relevant to the broader questions in this review with the widest possible dates.
• Recent systematic reviews on the use of oxygen in the management of suspected heart attack {Nicolaou 2015 e121} and ROSC post resuscitation of sudden cardiac arrest {Wyckoff 2022 e645] have found evidence of harm with administration of oxygen. There are a number of conditions where oxygen is still recommended, such as following carbon monoxide poisoning and resuscitation of divers who have used compressed gas, but no scoping reviews of these topics identified.
• First Aid provider organizations are increasingly training and equipping their members to give supplementary oxygen, hence there is a need-to-know what benefits and harms are associated with the use of supplementary oxygen in the first aid setting.

2. Narrative summary of evidence identified

• This scoping review did not identify any articles directly addressing the PICOST.
• This search did not identify the papers identified in the ILCOR CoSTR of 2015 {Zideman 2015 e225] because all but one of those papers related to the use of supplementary oxygen in palliative care initiated by medical officers and one was an audit of patients treated by EMS.
• The papers identified related to three main areas: supplementary oxygen for the treatment of carbon monoxide poisoning in the pre-hospital setting, supplementary oxygen in the treatment of decompression injuries/illness in divers using compressed gas and titrated oxygen in the treatment of persons with chronic obstructive pulmonary disease (COPD). One paper was identified about the first aid treatment of spinal cord injury.

Carbon Monoxide Poisoning

There were 6 papers identified relating to the treatment of carbon monoxide poisoning. These consisted of 4 literature reviews {Olson, 1984 #22517} {Kao 2006 99}, {Koster 2003 80}, {Winter 1976 1502}, one retrospective case series {Smith 1970 65} and one evidence-based guideline {Jüttner 2021 Doc13}. They concurred on the need to administer oxygen as soon as possible and in the highest oxygen concentration possible until more advanced care is available. All of these papers were mostly about the advanced care of carbon monoxide poisoning but contained sections on first aid or pre-hospital care.

Diving Emergencies

There were 11 papers identified on the treatment of divers using compressed gas with decompression injuries and/or illness. These consisted of 6 literature reviews{Shinnick 1994 105; Moon 2009 81; Pollock 2017 301; Spira 1999 180; Vann 2011 153; Whayne 2018 344}, 3 retrospective case series{Dick 1985 667; Liow 2009 e173; Longphre 2007 43}, one paper given at a conference (a Literature Review){Lippmann 2003 192} and one laboratory study of healthy volunteers{Blake 2015 79} to determine the best non-invasive technique for administering supplementary oxygen to achieve the highest tissue oxygen tension. This latter study found that a nonrebreather mask at oxygen flow of 15L/min was best of the non-invasive techniques readily available in the field. The rest of the papers concurred on the need to administer oxygen as soon as possible and in the highest oxygen concentration possible until more advanced care is available. All of these papers were mostly about the advanced care, mostly the use of hyperbaric oxygen, but contained sections on first aid or pre-hospital care.

Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD)

There were 13 papers identified on the use of oxygen for the acutely breathless patient related to the use of “high flow” vs titrated supplementary oxygen in out of hospital patients with suspected, proven or acute exacerbation of COPD (i.e., moderate heterogeneity of the patient population). The definition of high flow oxygen varied between studies, but typically described as 8-10 L/min by nonrebreather face mask (NRFM), 10 – 15 L/min by NRFM, 5 or more L/min by face mask and 4 or more L/min by nasal cannula. In some studies, high flow oxygen is not defined, and instead of studying the oxygen flow rate, the patient’s oxygen saturation was followed to determine outcomes.

• One paper {Austin 2006 Cd005534} was a Cochrane review of EMS use of high flow oxygen vs titrated oxygen which found no published papers directly related to the question but noted that two studies were underway.
• One paper {Austin 2010 c5462} described a cluster randomized trial of high flow (8-10 L/min via NRFM) vs titrated oxygen (saturations 88-92%) by EMS on mortality rate in COPD which found a RR of 4.5 for high flow oxygen in AECOPD.
• One paper (Ntoumenopoulos 2011) described a cluster randomized trial of high flow oxygen (8-10 L/min via NRFM compared with titrated oxygen via nasal prongs to maintain an oxygen saturation between 88% and 92%. Mortality in the intervention and control groups was 4% (n = 7) and 9% (n = 21), respectively. The relative risk was 0.42 (95% CI 0.20 to 0.89). Similar results were demonstrated when only those patients who had a physician-confirmed diagnosis of COPD were included in the analyses (mortality of 2%, n = 2, vs 9%, n = 11, and relative risk of 0.22, 95% CI 0.05 to 0.9]). This paper appears to be reporting the same data from the study by Austin (Austin 2010 c5462).
• One paper {Wijesinghe 2011 618} was a retrospective study which found increased oxygen flow was associated with increased risk of death, assisted ventilation, or respiratory failure with an OR of 1.2 (95% CI 1.0-1.4) per 1 L/min increase in oxygen flow. Increasing PaO2 was associated with a greater risk of poor outcome with an OR of 1.1 (95% CI 1.0-1.3) per 10 mmHg higher PaO2.
• One paper {Cameron 2012 684} was a retrospective study which compared mortality between PaO₂ on ABG within 4 hours of arrival of <88%, 88-96% and >96% in patients brought to hospital by EMS and found a hazard ratio of 9 for saturation >96% and 2 for saturations <88%.
• One paper {Pilcher 2015} was an “Expert review of the evidence on oxygen therapy in acute exacerbations in chronic obstructive pulmonary disease.” The review concluded “In acute exacerbations of COPD, there is a 2.4-fold increase in the risk of death if patients receive high concentration oxygen therapy, compared with titrated oxygen therapy” based on the paper by Austin et al, 2010. {Austin 2010}
• A retrospective audit (Ringbaek 2015 2} of AECOPD patients who received pre-hospital oxygen aimed to identify those patients who received “inappropriate oxygen therapy”, based on an oxygen saturation level of 92% or greater measured in the ambulance immediately before arrival to the emergency department. Data from total of 352 (88.7%) of 397 patients who received oxygen showed an oxygen saturation of 92% or greater in the ambulance just before arrival, and these patients were deemed to have received inappropriate oxygen therapy. The group of patients was noted to have a high frequency of respiratory acidosis at hospital admission, need for ventilatory support (12.5%) and an in-hospital mortality of 3.4%. Of 398 patients in which the oxygen flow was recorded, 344 (86.4%) were treated with high concentration oxygen, defined as 5 or more L/min on mask or 4 or more L/min by nasal cannula. Of note, patients treated with low to moderate concentrated oxygen (1-4 L/min FM or 1-3 L/min NC) had a tendency towards higher in-hospital mortality compared with the group that received high concentration oxygen (13.2% vs 5.2%; p=0.05)
• One paper {Lumholdt 2017 A8} reported a retrospective study of the oxygen saturation of 111 patients with respiratory conditions brought to ED by EMS and found to have acidosis and CO₂ retention. They found the 11 patients with CO₂ retention had a mean oxygen saturation of 84% on presentation to EMS and 95% on arrival in ED. They inferred this was due to excessive oxygen administration before arrival in hospital.
• One paper {Bentsen 2020 76} was a retrospective study of 30-day mortality of 707 patients with COPD brought to hospital by ambulance before and after implementation of a pre-hospital oxygen protocol, 56 patients with AECOPD had high-flow oxygen from April to September 2012 and 132 AECOPD were in the titrated oxygen group. For AECOPD, 30-day mortality was 19.6% vs 4.6% (p=0.001). The odds ratio and 95% CI for 30-day mortality was significant in the AECOPD subgroup (0.44 [0.26–0.75]), and the OR and 95% CI values were 0.38 [0.19–0.76] for 7-day mortality and 0.64 [0.4–0.96] for 90-day mortality in these patients. However, there were many confounders. One concerning thing about the study is that the “high flow” group appears to have received 12 LPM (6 - 14), the same as the titrated group. The authors note that “surprisingly, the measured levels of oxygen delivery found, were not as high as expected using the high-flow protocol. There could be two reasons for this. As the authors stated, “First, the ambulance personnel might already have initiated titrated oxygen delivery to more appropriate saturation levels, even though this was not the protocol at the time. Second, the time it took to provide nebulisation therapy may have used a larger proportion of the transit time, so that patients experienced a longer time with a lower oxygen flow compared to the use of regular supplementary oxygen. The difference in delivered oxygen therapy in the pre-hospital setting of our study did not differ in the two treatment groups. This could be due to registration of such therapy, as only one therapy level was recorded in the ambulance records, even though the patients might have received different levels of therapy, especially in the titrated period.” This is a large confounder when it comes to baseline data, as patients may have had various SpO2 levels during transit time to the ED. “
• One paper was a Cochrane review {Kopsaftis 2020 Cd005534}. This review found the paper by Austin et al {Austin, 2010 3065} which has been noted above. This study had 405 participants but only 214 with diagnosis of AECOPD included in the analysis. Intervention group received titrated O2 by nasal prongs to reach 88-92% oxygen saturation with concurrent nebulized bronchodilator treatment with compressed air via face masks over nasal prongs. The control group received “high flow” oxygen at 8 L/min to 10 L/min by NRFM with nebulizer bronchodilators administered with oxygen at 6 L/min to 8 L/min. The only outcome with statistically significant findings was mortality, both respiratory related and all-cause with a low certainty of evidence. For “high flow oxygen” relative risk was 0.22 (0.05 - 0.97) Anticipated absolute effect 94 per 1000 with high flow oxygen, 21 per 1,000 (5-91) with titrated oxygen. "A difference in mortality was observed, with 11 deaths in the high-flow oxygen arm compared to two deaths in the titrated oxygen arm (P = 0.05). This translates to a number needed to treat for an additional beneficial outcome (NNTB) of 14 (95% CI 12 to 355) with administration of titrated oxygen therapy. All deaths occurred after arrival at the hospital; two were in intensive care. Respiratory failure was the cause of mortality in all cases, with approximately 70% of deaths occurring within the first five days following admission for both treatment arms." However, “the paucity of evidence somewhat limits the reliability of these findings and generalisability to other settings.”

• One paper{Hodroge 2020 849} was an evidence based guideline mostly about advanced care, but did note “Literature review revealed that oxygen titration to no more than 94-96% for most acutely ill medical patients and to 88-92% in patients with acute chronic obstructive pulmonary disease (COPD) exacerbation is associated with decreased mortality” based on the paper by Austin et al { Austin 2010}
• One paper{Gottlieb 2022 214} was the German evidence-based guideline noting the risks of high flow oxygen in the absence of reliable pulse oximetry.
• The last included paper of this group{Barnett 2022 262} is the Australia and New Zealand Thoracic Society Guidelines for oxygen administration. This is based on a "targeted literature review." The key recommendations relevant to the current PICOST are: assess oxygenation, oxygen requires prescription and to set oxygen saturation targets of 88-92% for potential hypercapnia, 92-96% for others.
• There were 2 randomised controlled trials registered at the time of the search which have not been completed{Jensen 2023; Gude 2023}. They may be the same trial registered in 2 separate registries, with a different first author, but the same trial protocol. These trial(s) may help to add more certainty to the findings systematic review on this subject in the future.

Other Conditions

There was one review paper on the use of supplementary oxygen in spinal injury {Green 1987 229}. This paper advised the use of supplementary oxygen for all spinal cord injuries “via nasal cannula or O₂ mask” “during the accident scene management and transportation phases.”

3. Narrative Reporting of the Task Force Discussions

• There is no direct evidence to suggest or suggest against routine first aid administration of oxygen in adults or children exhibiting signs or symptoms of shortness of breath, difficulty breathing, or hypoxia outside of a hospital.
• All the evidence in the 2015 review {Zideman 2015 278} was indirect and mostly related to the use of oxygen in patients in palliative care but was the most applicable. The current review has yielded evidence that supplementary oxygen is harmful in patients with acute exacerbations of chronic obstructive pulmonary disease in the setting of EMS and needs to be titrated to the patient’s oxygen saturation. The evidence of harm is a higher mortality rate if high flow oxygen rather than oxygen flow titrated to produce saturations of 88-92%. This is based on one cluster RCT (Austin 2010 3065). The remaining observational studies report mixed results and there is significant heterogeneity between the studies and confounders.
• The search did not reveal evidence of benefit of supplementary oxygen in the first aid setting; this may be because this question, oxygen vs none, has not been asked. This review specifically excluded the use of supplementary oxygen in a number of settings because these indications have been covered in recent reviews, namely acute coronary syndrome {Nikolaou 2015 e121}, suspected stroke {Singletary 2020 S284}, after return of spontaneous circulation following cardiac arrest {Wyckroff 2022 e645} and drowning {Bierens 2023 1}.
• The task force has included highly specialized physiological circumstances with respect to the use of oxygen, including injuries or illness following the use of compressed gas in diving (eg: SCUBA) and carbon monoxide poisoning. The evidence here is all more than 20 years old, but of the clear opinion that supplementary oxygen should be administered pre-hospital.
• This review has major implications for first aid providers given the CoSTR in 2015 {Zidemann 2015 e225} permitted the use of oxygen in patients displaying symptoms of hypoxia or shock. It would seem prudent to urge caution when there is a possibility of COPD in guidelines concerning administration of oxygen by first aid providers and that supplementary oxygen should only be titrated to achieve a target saturation of 88-92%, but we acknowledge that recognition of COPD and possibly the use of pulse oximetry may be beyond the skill set of first aid. However, some organizations teaching advanced first aid or first aid oxygen courses to lay responders do include teaching on the use of pulse oximetry (e.g., St John Ambulance Australia), so there may be circumstances where the supplementary administration of oxygen by first aid providers is common practice. It should also be noted that the use of pulse oximetry by first aid providers is the subject of a separate scoping review by the First Aid Task Force.
• The task force noted that the papers found were from high resource settings and that it is likely that chronic obstructive pulmonary disease is more prevalent in low resource settings and that further study of the first aid treatment of COPD in low resource settings would be extremely valuable.
• The First Aid Task Force agreed that there was insufficient evidence to pursue a systematic review of the very broad topic of first aid oxygen use for symptoms or signs of shortness of breath, difficulty breathing or hypoxia of uncertain aetiology. Previous ILCOR reviews have focused on the use of oxygen in suspected acute stroke, acute coronary syndrome and for patients who are post cardiac arrest with return of spontaneous circulation. Although limited, there appears to be sufficient evidence identified to undertake future systematic reviews on first aid administration of oxygen for carbon monoxide poisoning and diving emergencies. In addition, a systematic review is warranted to further develop recommendations for first aid oxygen administration in acute COPD exacerbations that may include recommendation for oxygen when pulse oximetry not available, and to consider provider differences and resources in these recommendations.
• The task force agreed that the body of evidence{Austin 2010; Barnett 2022; Bentsen 2020; Cameron 2012 684; Gottlieb 2022 214 C5462; Hodroge 2020 849; Kopsaftis 2020 Cd005534; Lumholdt 2017 A8; Ntoumenopoulos 2011 70008; Pilcher 2015 287; Wijesinghe 2011 618; Ringbaek 2015 2} on the first aid use of supplementary oxygen in persons with an acute exacerbation of chronic obstructive pulmonary disease warrants a good practice statement pending a systematic review of the evidence revealed in this scoping review.

4. Good Practice Statement(s)

• When a first aid provider trained in oxygen use administers oxygen for acute difficulty breathing to a person who confirms they have chronic obstructive pulmonary disease it is suggested to use pulse oximetry and titrate the oxygen to maintain an oxygen saturation between 88 – 92%.
• Although high flow oxygen should in general be avoided for patients with chronic obstructive pulmonary disease with difficulty breathing in the out-of-hospital setting, it should not be withheld in the presence of life-threatening hypoxia (oxygen saturation <88%).

Knowledge Gaps

• Does administration of oxygen in the out of hospital setting improve survival in patients presenting with shortness of breath or hypoxemia other than the specialist indications such as carbon monoxide poisoning or divers who have used compressed gas?
• Can first aiders recognize carbon monoxide poisoning and appreciate the gravity of the poisoning?
• Can first aid providers distinguish COPD?
• Can first aid providers use pulse oximetry accurately to target oxygen administration to 88-92%?

References

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