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 applicable
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 applicable
Task Force Synthesis Citation
Singletary EM, Douma M, Kung J, Myhre C, MacKenzie E, on behalf of the International Liaison Committee on Resuscitation First Aid Task Force. Pulse Oximetry Use in the First Aid Setting: Task Force Synthesis of a Scoping Review [Internet] Brussels, Belgium: International Liaison Committee on Resuscitation (ILCOR) First Aid Task Force, 2022 November 25. 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 use of pulse oximetry in a first aid setting, conducted by the ILCOR First Aid Task Force Scoping Review team. Evidence from the peer-reviewed and gray literature was sought and considered by the First Aid Task Force.
Scoping Review
Singletary EM, Douma M, Kung J, Myhre C, MacKenzie E, on behalf of the International Liaison Committee on Resuscitation First Aid Task Force. Use of Pulse Oximetry in the First Aid Setting: A Scoping Review. (in preparation)
PICOST
The PICOST (Population, Intervention, Comparator, Outcome, Study Designs and Timeframe)
Population: Adults and children in the out-of-hospital or home setting with an acute illness or injury
Intervention: Use of pulse oximetry in addition to standard first aid assessment
Comparators: Standard first aid assessment without the use of pulse oximetry
Outcomes: Any clinical outcome
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. Grey literature, social media and non-peer reviewed studies, unpublished studies, conference abstracts and trial protocols are eligible for inclusion.
Timeframe: All years.
Literature search updated to November 16, 2022
Search Strategies
Summary of the databases that were searched and important search terms.
Database Search:
The medical librarian co-developed our search strategy with us and executed comprehensive searches in Ovid MEDLINE, Ovid Embase, CINAHL, Scopus, Web of Science Core Collection, and Cochrane Library (via Wiley) on June 9, 2022. To capture all relevant literature concerning lay-person or home use of SpO2 monitors, relevant keywords and controlled vocabulary were carefully selected. No language or date limits were applied. Refer to the appendices for full-text search strategies. A total of 7424 results were retrieved and after removing duplicates, 4204 unique results remained for the initial title and abstract screening in a web-based tool called Covidence (www.covidence.org).
In addition to subscription databases, the research team searched trial registries (e.g., ClinicalTrials.gov) and Google Scholar. The first 200 results from Google Scholar were evaluated for inclusion, which has been demonstrated to be a reasonable number of results to screen since there is high overlap between Web of Science and Google Scholar. Bibliographies from included studies were also reviewed.
The database search was updated on November 16, 2022. XXX additional studies were screened and X were included.
Grey Literature Search:
Grey literature articles were obtained by searching Google, GoogleNews, Apple News and Twitter for key terms “Pulse oximeter” AND “first aid”
Over 9,250,000 results returned with the search of Google.com. Titles were screened for the first 20 pages (10 per page). After exclusion of advertisements for purchase of pulse oximeters, 17 articles were included. No additional articles were identified through GoogleNews, Apple News or Twitter.
Inclusion and Exclusion criteria
Inclusion criteria:
- Adult and pediatric patients
- Description of use of pulse oximeter for acute symptoms of illness or injury in an out-of-hospital or home (first aid) setting
- Use in a first aid kit described
Exclusion criteria:
- Animal studies
- Sleep studies (i.e., obstructive sleep apnea
- Neonatal/infant monitoring
- Remote monitoring by healthcare professionals (i.e., for COVID-19)
- Routine home self-monitoring for chronic disease or illness without new/acute symptomatology (i.e., COPD, asthma, pneumonia, COVID-19)
- Feasibility studies
- Protocols
Data Tables: FA Pulse oximetry Data tables
Task Force Insights
1. Why this topic was reviewed.
This topic was prioritized for review by the FA Task Force due to the increasing availability of and use of pulse oximeters at home, during the COVID-19 pandemic, and because task force members were aware of articles published in leading newspapers and magazines describing the inclusion of pulse oximeters in first aid kits.
Prior to the COVID-19 pandemic, pulse oximetry was in use by some healthcare practitioners for routine monitoring of patients with chronic diseases such as obstructive sleep apnea, asthma and COPD, including self-monitoring during prescribed exercise.
During the height of the COVID-19 pandemic, pulse oximetry became an accepted means of remotely monitoring patients with COVID-19 who were discharged from a hospital emergency department or inpatient setting and was used to identify those patients with ‘silent hypoxemia’ who required re-evaluation for admission. Programs using home monitoring of oxygen saturation typically involved a brief period of instruction on its use and required daily or more frequent check-ins with a monitoring person to collect oximetry readings combined with clinical symptomatology.
The demand for portable fingertip pulse oximeters led to increased production of inexpensive fingertip pulse oximeters by multiple manufacturers. Oximeters became commonly available in pharmacies and online in many countries, with an estimated global market of US$ 1.43 million in 2021{ReporterLink.com}. At the same time, several ILCOR First Aid Task Force members became aware that members of the public were posting on social media platforms their personal recommendations for the use of pulse oximeters and proposing their inclusion in home first aid kits. Articles in U.S. major newspapers and magazines with titles such as “Pulse oximeters are back in stock - here's why you may want one” led to additional articles describing home/first aid use. Social media postings continue today, with posts such as, ‘they are as easy to use as a digital thermometer” and “add a pulse oximeter to the home first aid kit just in case anyone in the house or on our street needs a quick oxygen saturation check”.
With this background, the First Aid Task Force considered it timely to undertake a scoping review of the literature to identify any evidence to support the use of pulse oximetry as a component of first aid assessment of acute symptoms associated with illness or injury.
2. Narrative summary of evidence identified
Database evidence identified:
Our PRISMA flow diagram can be found in Figure 1.
Our database review of published literature identified 7424 articles (4204 after removal of duplicates). After screening titles and abstracts, 15 studies and 1 case report were identified for full text review. Eleven studies enrolled patients with COVID-19, three enrolled patients with COPD, one enrolled people with pulmonary embolus and one enrolled persons with “mixed” lung diseases. Only four studies reported the type and brand of pulse oximeter used. Five of the studies originated in North America and another five in Western Europe. Two studies were conducted in Australia with another in Bangladesh and the final study in South Africa. All but three studies were published in 2020 or more recently, with the oldest study having been published in 1999.
All studies were ultimately excluded due to their enrolling patients in home monitoring programs for a known, diagnosed infection or disease. The single case report was of a 72-year-old man with COVID-19 being taken care of at home by his physician son who utilized a home SpO2 monitor.
The studies identified in our database review and ultimately excluded are of little relevance to first aid but provided information regarding use of pulse oximetry for routine, daily self-monitoring by patients or parents of patients with asthma, COPD, cystic fibrosis and similar conditions (Table 1). Many studies described hospital programs that used remote daily monitoring of patients with COVID-19 after discharged home and following a brief instructional course on oximetry use.
A systematic review identified in our search, but ultimately excluded, described the effectiveness and safety of pulse oximetry in the remote monitoring of COVID-19 patients (Alboksmaty 2022). The authors state that monitoring of pulse oximetry at home enables early identification of a decrease in SpO2 prior to worsening of symptoms, though they were unable to identify any studies that provided clear evidence that it impacted health outcomes in any way. In another study that underwent full text review but ultimately excluded, an incidental low pulse oximetry reading without worsening of any other symptoms was the only reason that 50% of patients who were ultimately hospitalized returned to the emergency department. (Shah 2020)
An excluded 2022 scoping review found that pulse oximetry, especially for remote patient monitoring, was very positively viewed by health care providers and patients alike; however, they did mention concerns about accuracy related to movement, battery life, too many false alarms and incorrect probe application (Rosic 2022).
Studies describing limitations in accuracy of pulse oximeters provide insights into potential difficulties with use and interpretation of readings by lay first aid providers. Several studies described discrepancies in readings from blood gas analysis compared with pulse oximetry related to skin pigmentation. In a mixed effects linear model, individuals with black, Asian or mixed ethnicity had a higher reading for oxygen saturation as measured by pulse oximetry than blood gas compared to individuals with a white ethnicity (excluding patients without ethnicity recorded) and adjusting for arterial blood gas oxygen saturation (black ethnicity +1.8%, 95% CI +0.2 to +3.4, p=0.04; Asian +1.9%, 95% CI +0.6 to +3.2, p=0.005; mixed ethnicity +3.2%, 95% CI −0.1 to +6.6, p=0.06). (Crooks 2022) Another excluded review concluded that “Pulse oximetry may overestimate oxygen saturation in people with high levels of skin pigmentation and people whose ethnicity is reported as Black/African American, compared with SaO2. The extent of overestimation may be small in hospital settings but unknown in community settings.” These findings are especially concerning as lay persons who use pulse oximeters for self-care/first aid may be unaware of these differences and may not recognize hypoxemia in persons with increased skin pigmentation (Shi 2022) In a third study, Black patients had nearly three times the frequency of occult hypoxemia that was not detected by pulse oximetry as White patients. (Sjoding 2020)
Grey literature evidence identified:
The 17 selected gray literature articles were published online and included reports by major news organizations, online magazine articles, blogs, review articles and opinion pieces by nonprofit organizations and commercial entities, one online textbook, and one bulletin from a federal advisory committee. (Table 2)
The most recent articles reported the results of studies published in 2022 showing inaccurate oximetry readings in persons of color, and of plans by the FDA to address this issue and other issues affecting accuracy and performance. On November 7, 2022 the FDA made recommendations for the use of pulse oximetry including warnings about their limitations in persons with poor circulation, skin pigmentation, varied skin thickness or skin temperature, current tobacco use, and fingernail polish. They further warned that FDA-approved pulse oximeters estimate blood oxygen saturation where reported saturation of 90% may represent an arterial blood saturation of 86-94%. In addition, they warned of the use of over-the-counter devices not intended for use in illness or injury. Over-the-counter oximeters are sold as a general wellness or sporting/aviation product and do not undergo FDA review and clearance. The FDA is in the process of analyzing additional postmarket data to understand how different factors including skin pigmentation may affect pulse oximeter accuracy{U.S.FDA 2022}
Several articles identified in the gray literature search described the home use of pulse oximetry for persons with COVID-19, and two suggested “updating” or “refreshing” home first aid kits with a pulse oximeter and other equipment such as oxygen cannisters. Several articles described potential uses of pulse oximetry for assessment in first aid (such as in austere environments) or for self-assessment or monitoring during COVID-19 illness without explicitly recommending their use but went on to describe different oximeter brands, with hyperlinks to sales pages. Some articles describe lack of accuracy of fingertip pulse oximeters and phone app oximetry readings or noted that being alert to symptoms and signs is also important. Most of the articles discussing pulse oximeters and when to use them were unreferenced and appeared to be at critical risk of bias due to commercial sales promotions.
3. Narrative Reporting of the task force discussions
The evidence identified in this scoping review did not pertain to the first aid use of a pulse oximeter as a means of assessment for acute symptoms from illness or injury, but rather pertained to outpatient remote monitoring (i.e., not symptom-initiated use) for asthma, COPD, cystic fibrosis, and other diseases. No direct evidence was identified to support or dissuade the use of pulse oximetry in first aid. Though there were reports of the early detection of asymptomatic hypoxemia, we also identified concerns regarding device limitations, accuracy, reliability, and racial disparities in oximetry reading.
The task force expressed concerns about storage of oximeters in first aid kits, battery life, issues with readings due to movement and vibration, and outdoor use in settings with high humidity or extremes of temperature. Additional concern was expressed about the accuracy of OTC oximeters sold as non-medical use devices and used by the public to assist with self-identification of hypoxemia and without training in their use, limitations and interpretation of findings.
The current review by the U.S. FDA of oximeters was discussed at length{U.S. FDA 2022}. Pulse oximeters are known to be associated with erroneous readings or inability to read SpO2.{Chan 2013 789} Falsely normal or elevated SpO2 readings may be associated with carbon monoxide poisoning and sickle cell anemia vaso-occlusive crises. Falsely low SpO2 values may occur with excessive movement, inherited forms of abnormal hemoglobin, and fingernail polish. Poor probe positioning and sepsis can cause falsely low or high SpO2. In our review of the literature for pulse oximetry in first aid, severe recent studies reported that increasing levels of skin pigmentation correlate with overestimates by pulse oximeters of arterial oxygen saturation. The ILCOR First Aid Task Force expressed concern that this topic requires additional research and consideration of implications for use in all settings.
Despite the lack of evidence to support a recommendation for the use of pulse oximeters in a first aid setting for assessment of acute illness or injury, and despite the many limitations to pulse oximetry, the Task Force acknowledges that pulse oximetry has become accepted for remote and home monitoring of several chronic and acute illnesses. Pulse oximeters are now stored or sold in many personal and commercial first aid kits. Future studies are encouraged to evaluate their use in first aid from many angles, including when to use one, what training may be needed, and determining if their use makes a difference in patient-centered outcomes.
It is the Task Force consensus that the evidence does not support a recommendation for (or against) the use of a pulse oximeter by first aid providers for assessment of acute illness or injury. However, we recognize that pulse oximeters are readily available for purchase and may be found in some first aid kits and be in use by some first aid providers. Because of this, the First Aid Task Force supports a good practice statement for those providers who use a pulse oximeter. This statement has been drafted considering the GRADE criteria for a Good Practice Statement. (Siedler 2019)
Good Practice Statement
First aid providers who use pulse oximeters for the assessment of acute illness or injuries should be proficient in their use and understand their limitations, including equipment factors, environmental considerations, and patient-specific factors that may produce inaccurate and unreliable readings.
The use of a pulse oximeter for first aid assessment should not supersede or replace physical assessment.
Knowledge Gaps
- There were no studies identified that evaluated the use of pulse oximetry in the first aid setting.
- No studies were identified that describe the ability of a first aid provider to recognize the limitations of pulse oximeters, or the ability to interpret oximetry readings.
- Resource requirements and training requirements for the first aid use of pulse oximetry are uncertain.
References
References listed alphabetically by first author last name in this citation format (Circulation)
Alboksmaty A, Beaney T, Elkin S, Clarke J, Darzi A, Aylin P, Neves AL. Effectiveness and safety of pulse oximetry in remote patient monitoring of patients with COVID-19: Ahmed Alboksmaty. Eur J Public Health. 2022 Oct 25;32(Suppl 3):ckac129.303. doi: 10.1093/eurpub/ckac129.303. PMCID: PMC9593659.
Chan ED, Chan MM, Chan MM. Pulse oximetry: understanding its basic principles facilitates appreciation of its limitations. Respir Med. 2013; 107(6):789-99. DOI: 10.1016/j.rmed.2013.02.004
Crooks CJ, West J, Morling JR, et al. Pulse oximeter measurements vary across ethnic groups: an observational study in patients with COVID-19. Eur Respir J. 2022;59(4):2103246. Published 2022 Apr 7. doi:10.1183/13993003.03246-2021
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Rosic T, Petrina N, Baysari M, Ritchie A, Poon SK. Patient and clinician use characteristics and perceptions of pulse oximeter use: A scoping review [published online ahead of print, 2022 Mar 18]. Int J Med Inform. 2022;162:104735. doi:10.1016/j.ijmedinf.2022.104735
Siedler M. Stating the “obvious”: A primer on good practice statements in GRADE guidelines. The U.S. GRADE Network (blog), Jan 30, 2019. Available at: https://usblog.gradeworkinggro...
Shah S, Majmudar K, Stein A, et al. Novel Use of Home Pulse Oximetry Monitoring in COVID-19 Patients Discharged From the Emergency Department Identifies Need for Hospitalization. Acad Emerg Med. 2020;27(8):681-692. doi:10.1111/acem.14053
Shi C, Goodall M, Dumville J, et al. The accuracy of pulse oximetry in measuring oxygen saturation by levels of skin pigmentation: a systematic review and meta-analysis. BMC Med. 2022;20(1):267. Published 2022 Aug 16. doi:10.1186/s12916-022-02452-8
Sjoding MW, Dickson RP, Iwashyna TJ, Gay SE, Valley TS. Racial Bias in Pulse Oximetry Measurement [published correction appears in N Engl J Med. 2021 Dec 23;385(26):2496]. N Engl J Med. 2020;383(25):2477-2478. doi:10.1056/NEJMc2029240
US Food & Drug Administration. Pulse oximeter accuracy and limitations: FDA safety communication. https://www.fda.gov/medical-de.... 19 Feb 2021, updated 7 Nov 2022