Overview

At the present time, despite a lack of definitive evidence, it is generally accepted that restoration of a normal, or near normal, arterial oxygen status in a patient presenting with acute hypoxia will improve that patient’s outcome. In the conscious, self-ventilating, acutely hypoxic patient, this is achieved by administration of inhaled supplemental oxygen therapy. In such a patient, we must avoid the deleterious effects of excessive oxygen dosage. In the common subgroup of patients at risk of oxygen-induced hypercapnia, we restore the arterial oxygen status to near normal.  Practitioners responsible for oxygen administration to patients must be able to 1) describe the normal oxygen status of the arterial blood, that is; the desired outcome of oxygen therapy 2) prescribe supplemental oxygen therapy based on an appropriate target oxygen saturation range defined by measurement of the SpO₂ on pulse oximetry 3) identify patients at risk of hypercapnia induced or aggravated by oxygen therapy and 4) adjust the target oxygen saturation range accordingly. Furthermore, when monitoring a patient on supplemental oxygen therapy, the practitioner must be able to 1) interpret and react to significant changes in the patient’s SpO₂ and 2) if it occurs, identify the onset of hypoventilation. This course addresses these performance needs.

Faculty

Planner and Author: Dr John Seery MB PhD

• Consultant Physician at St. Vincent's University Hospital, Dublin, Ireland
• Lecturer at the School of Medicine and Medical Science, University College Dublin, Ireland
• Studied medicine at the University of Cambridge, United Kingdom
• A Natural Sciences graduate of Trinity College Dublin, Ireland
• PhD in Cell Biology from University College London, United Kingdom

 

Planner: Dr Karen Strahan PhD (University of Cambridge), Head of Editorial
Planner: Tommy O'Sullivan, CME Manager
 

Estimated Time to Complete

5.0 hours

Target Audience

• Physicians
• Nurses
• Nurse Practitioners
• Physician Assistants
• Paramedics

Learning Objectives

Upon successful completion of this activity, you will be able to:

• Describe the normal oxygen status of the arterial blood.
• Explain the role of pulse oximetry and arterial blood gas analysis in monitoring a patient’s response to supplemental oxygen therapy.
• Explain the clinical significance of the oxygen hemoglobin dissociation curve.
• Explain the logic underlying the target oxygen saturation range employed during supplemental oxygen therapy.
• Explain the advantages and limitations of pulse oximetry in the assessment of arterial oxygen status.
• Explain the mechanism of acute hypercapnia emerging during exacerbations of chronic lung disease characterized by airways obstruction.
• Prescribe an appropriate target oxygen saturation range during supplemental oxygen therapy in patients presenting acutely unwell to the Emergency Department (ED).
• Identify patients at risk of oxygen-induced hypercapnia.
• Titrate oxygen dosage to the target oxygen saturation range.
• Adjust the target oxygen saturation range in a patient at risk of oxygen-induced hypercapnia.
• Recognize and respond appropriately to the emergence of hypoventilation during supplemental oxygen therapy.

Course Content

• Introduction
• The Oxygen Content of the Arterial Blood
• The Normal Oxygen Status of the Arterial Blood
• The Oxygen Fractions of the Arterial Blood
• The SpO₂: Strengths and Limitations
• The Target Oxygen Saturation Range
• The Shape of the Oxygen Hemoglobin Dissociation Curve: Clinical Implications
• Case Study: The Role of the SpO₂ in Oxygen Therapy
• Monitoring Oxygen Therapy: The Role of the SpO₂
• Case Study: Clinical Deterioration during Oxygen Therapy
• The Emergence of Hypercapnia during Oxygen Therapy
• A Near Miss in a Tiring Asthmatic
• What is COPD?
• Case Study: Oxygen Toxicity in Undiagnosed COPD
• Summary
• Quiz
• Essential Reading

Release date

15-JUN-2023

Expiration date

15-JUN-2026

Instructions for Participation

Participants must complete the online activity during the valid period as noted above.
Follow these steps:

1. View videos in sequence
2. Read the papers on the Essential Reading List
3. Complete quiz
4. Complete the activity evaluation form to provide feedback for continuing education purposes and for the development of future activities
5. Download the Certification of Completion

Relevant Financial Disclosures

Acadoodle adheres to the ACCME's Standards for Integrity and Independence in Accredited Continuing Education. Any individuals in a position to control the content of a CE activity, including faculty, planners, reviewers or others are required to disclose all relevant financial relationships with ineligible entities (commercial interests). All relevant conflicts of interest have been mitigated prior to the commencement of the activity.

Planners and faculty for this activity have no relevant financial relationships with commercial interests to disclose.

Bibliography

General

O’Driscoll BR et al. Guideline for emergency oxygen use in adult patients. Thorax. 2008;63(Suppl 6):vi1-68.
https://thorax.bmj.com/content/63/Suppl_6/vi1.long

O’Driscoll BR et al. British Thoracic Society guideline for oxygen use in healthcare and emergency settings. BMJ. 2017;4:e000170. Doi:10.1136/bmjresp-2016-000170.
https://bmjopenrespres.bmj.com/content/4/1/e000170

Nitzan M et al. Pulse Oximetry: fundamentals and technology update. Medical Devices: Evidence and Research. 2014:7:231-9.
https://www.dovepress.com/getfile.php?fileID=20747

Collins JA et al. Relating oxygen partial pressure, saturation and content: the hemoglobin-oxygen dissociation curve. Breathe 2015;11:194-201.
https://breathe.ersjournals.com/content/11/3/194.short

Kane B et al. Emergency oxygen therapy: from guidelines to implementation. Breathe 2013;9:246-53.
https://breathe.ersjournals.com/content/9/4/246

Campbell EJM. Oxygen administration. Anaesthesia. 1963;18(4):503-6.
https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/epdf/10.1111/j.1365-2044.1963.tb13575.x

Campbell EJM. Respiratory failure: The relation between oxygen concentrations of inspired air and arterial blood. Lancet. 1960;276(7140):10-11.
https://www.sciencedirect.com/science/article/abs/pii/S0140673660926593

Kelly C. Oxygen therapy: time to move on? Ther Adv Respir Dis. 2014;8(6):191-9.
https://journals.sagepub.com/doi/pdf/10.1177/1753465814549011

Kelly CA & Madden M. How do health-care professionals perceive oxygen therapy? A critical interpretive synthesis of the literature.
Chronic Resp Dis. 2015;12(1):11-23.
https://journals.sagepub.com/doi/full/10.1177/1479972314562408

Pretto JJ, Roebuck T, Beckert L, Hamilton G. Clinical use of pulse oximetry: Official guidelines from the Thoracic Society of Australia and New Zealand. Respirology. 2014:19:38-46.
https://pubmed.ncbi.nlm.nih.gov/24251722/

Tretter V et al. Investigating Disturbances of Oxygen Homeostasis: From Cellular Mechanisms to the Clinical Practice. Front Physiol. 2020;11:article
https://www.frontiersin.org/articles/10.3389/fphys.2020.00947/full

Clark FJ and von Euler C. On the regulation of depth and rate of breathing. J Physiol. 1972;222:267-295.
https://physoc.onlinelibrary.wiley.com/doi/epdf/10.1113/jphysiol.1972.sp009797

Shen et al. Impact of partial pressure of oxygen trajectories on the incidence of acute kidney injury in patients undergoing cardiopulmonary bypass. J Cardiol. 2022;79(4):545-50.
https://www.sciencedirect.com/science/article/abs/pii/S0914508721003087

Farquhar H et al. Systematic review of studies of the effect of hyperoxia on coronary blood flow. Am Heart J. 2009;158(3):371-7.
https://www.sciencedirect.com/science/article/abs/pii/S0002870309004608

Schjørring OL & Rasmussen BS. The paramount parameter: arterial oxygen tension versus arterial oxygen saturation as target in trials on oxygenation in intensive care. Crit Care. 2018;22:324-6.
https://ccforum.biomedcentral.com/articles/10.1186/s13054-018-2257-9

Jones G & Barker A. Reference Intervals. Clin Biochem Rev. 2008;29 (suppl 1):S93-7.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2556592/

Lin J et al. The effects of gel-based manicure on pulse oximetry. Singapore Med J. 2019;60(8):432-5.
http://www.smj.org.sg/article/effects-gel-based-manicure-pulse-oximetry#:~:text=Pulse%20oximetry%20is%20the%20standard%20monitoring%20technique%20of,recent%20years%20due%20to%20their%20

Clowes GH et al. A comparison of the Physiological Effects of Hypercapnia and Hypoxia in Production of Cardiac Arrest.
Ann Surg. 1955; 142(3):456-59
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1465082/pdf/annsurg01282-0130.pdf

Echevarria C et al. Oxygen therapy and inpatient mortality in COPD exacerbation. Emergency Med J. 2021 38(3):170-7.
https://emj.bmj.com/content/38/3/170

Röttgering JG et al. Determining a target SpO₂ to maintain PaO₂ within a physiological range. PLOS ONE. 2021 Published online.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0250740

McFadden ER. Acute Severe Asthma. Am J Resp Crit Care Med. 2003;168:740-59.
https://www.atsjournals.org/doi/full/10.1164/rccm.200208-902SO

Johnson AJ et al. Circumstances of death from asthma. BMJ 1984;288:1870-2.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1441768/pdf/bmjcred00506-0020.pdf

Molfino NA et al. Respiratory Arrest in Near Fatal Asthma. NEJM. 1991;324:285-8.
https://www.nejm.org/doi/10.1056/NEJM199101313240502?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200www.ncbi.nlm.nih.gov

The Oxygen Dissociation Curve of Hemoglobin

Barcroft J & King WOR. The effect of temperature on the dissociation curve of blood. J Physiol. 1909;39(5):374-84.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1533669/

Adair GS et al. The Hemoglobin System: VI. The Oxygen Dissociation Curve of Hemoglobin. J Biol Chem. 1925;63(2):529-45.
https://www.sciencedirect.com/science/article/pii/S0021925818850189

Leow MKS. Configuration of the hemoglobin oxygen dissociation curve demystified: a basic mathematical proof for medical and biological sciences undergraduates. Adv Physiol Educ 2007; 31:198-201.
https://journals.physiology.org/doi/full/10.1152/advan.00012.2007

Yartsev A. The oxyhaemoglobin dissociation curve. Deranged Physiology.
https://derangedphysiology.com/main/cicm-primary-exam/required-reading/respiratory-system/Chapter%20112/oxyhaemoglobin-dissociation-curve

Wick KD et al. Pulse Oximetry for the diagnosis and management of acute respiratory distress syndrome. 2022.
https://pubmed.ncbi.nlm.nih.gov/36049490/

Ren S et al. Machine learning based algorithms to impute PaO₂ from SpO₂ values and development of an online calculator. 2022. Nature. Published online.
https://www.nature.com/articles/s41598-022-12419-7

Hooley J. Decoding the oxyhemoglobin dissociation curve. American Nurse Today. Published online.
https://www.myamericannurse.com/wp-content/uploads/2014/12/ant1-CE-Oxyhemogglobin-1219.pdf

Normal Reference Ranges

Gillies IDS et al. Analysis of possible factors influencing PaO₂ and (PAO₂-PaO₂) in patients awaiting operation. Br J Anaesth. 1977;49:427-37.
https://www.sciencedirect.com/science/article/pii/S0007091217454754
In addition, to their own studies, the authors review data published up to 1977 on the normal range of arterial oxygen tension.

Filley GF et al. Alveolar and arterial oxygen tensions and the significance of the alveolar-arterial oxygen tension difference in normal men. J Clin Invest. 1954;33(4):517-29.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1087266/

Cerveri I et al. Reference values of arterial oxygen tension in the middle-aged and elderly. Am J Respir Crit Care Med. 1995;152(3):934-41.

Higgins C. Adult reference Intervals for blood gas. acutecaretesting.org. 2012. Published online.
https://acutecaretesting.org/en/journal-scans/adult-reference-intervals-for-blood-gases

Klaeustrup E, Trydal T, Pedersen JF, Larsen JM, Lundbye-Christensen S, Risom Kristensen S. Reference intervals and age and gender dependency for arterial blood gases and electrolytes in adults. Clin Chem Lab Med. 2011;49(9):1495-500.

National Views on Acute Supplemental Oxygen Therapy

USA

No national guidelines at the time of writing (2023).

United Kingdom

O’Driscoll BR et al. British Thoracic Society guideline for oxygen use in healthcare and emergency settings. BMJ. 2017;4:e000170. Doi:10.1136/bmjresp-2016-000170.
https://bmjopenrespres.bmj.com/content/4/1/e000170

Australia & New Zealand

Beasley R et al. Thoracic Society of Australia and New Zealand oxygen guidelines for acute oxygen use in adults: ‘Swimming between the flags’. Respiriology 2015;20:1182-91.

Canada

Siemieniuk RAC et al. Oxygen Therapy for acutely ill medical patients: a clinical practice guideline. BMJ 2018
https://www.bmj.com/content/363/bmj.k4169.long

Ireland

Butler M et al. Irish guidelines on the administration of oxygen therapy in the acute clinical setting in adults in 2017.
https://irishthoracicsociety.com/wp-content/uploads/2017/12/O2-Guidelines-Final.pdf
Includes useful review of the evidence underlying guidelines on supplemental oxygen therapy.

Germany

Gottlieb J et al. German S3 Guideline: Oxygen Therapy in the Acute care of Adult Patients. Respiration 2022;101:214-52.
https://www.karger.com/Article/FullText/520294
Includes useful review of the evidence underlying guidelines on supplemental oxygen therapy.

France

Allardet-Sevent J et al. Benefits and risks of oxygen therapy during acute medical illness: Just a matter of dose! Rev Med Interne 2019;40(10):670-6.

Additional Reading

Collins JA et al. Relating oxygen partial pressure, saturation and content: the hemoglobin-oxygen dissociation curve. Breathe 2015;11:194-201.
https://breathe.ersjournals.com/content/11/3/194.short

Yartsev A. The oxyhaemoglobin dissociation curve. Deranged Physiology.
https://derangedphysiology.com/main/cicm-primary-exam/required-reading/respiratory-system/Chapter%20112/oxyhaemoglobin-dissociation-curve"

Whyte MB & Kelly P. The normal range: it is not normal and it is not a range. Postgrad Med J. 2018.;94(1117). Published online.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6352401/

Nitzan M et al. Pulse Oximetry: fundamentals and technology update. Medical Devices: Evidence and Research. 2014:7:231-9.
https://www.dovepress.com/getfile.php?fileID=20747

Bleetman D. British Thoracic Society guidelines on emergency oxygen therapy for adults. Journal of paramedic practice. Nov 4 2011.
https://www.paramedicpractice.com/opinion/article/british-thoracic-society-guidelines-on-emergency-oxygen-therapy-for-adults
Interesting take on why patients come into hospital on high levels of oxygen therapy.

Barnett A et al. Thoracic Society of Australia and New Zealand Position Statement on Acute Oxygen Use in Adults: ‘Swimming between the flags. Respiriology. 2022;27(4):262-76.
https://onlinelibrary.wiley.com/doi/10.1111/resp.14218

Nath S et al. An audit of supplemental oxygen prescribing practices in an inpatient setting and its financial burden. Eur Resp J. 2018;52(suppl 62).
https://erj.ersjournals.com/content/52/suppl_62/PA3160

Fu ES et al. Supplemental oxygen impairs detection of hypoventilation by pulse oximetry. Chest 2004;126(5):1552-8.
https://pubmed.ncbi.nlm.nih.gov/15539726/

Downs JB. Has oxygen administration delayed appropriate respiratory care? Fallacies regarding oxygen therapy. Respir Care. 2003;48:611-20.
https://rc.rcjournal.com/content/48/6/611.short

Echevarria C et al. Oxygen therapy and inpatient mortality in COPD exacerbation. Emergency Med J. 2021 38(3):170-7.
https://emj.bmj.com/content/38/3/170

Rothwell RP et al. Lessons from the national asthma mortality study: deaths in hospital. NZ Med J. 1987;100(821):199-202.
https://pubmed.ncbi.nlm.nih.gov/3455478/
(abstract) no online access to article

Acknowledgments

Illustrative arterial blood gas results were constructed in part using on online calculator produced by Weill Medical College of Cornell University.
http://www-users.med.cornell.edu/~spon/picu/calc/basecalc.htm

Useful material and insights were provided by my team at the time of writing. Thanks to Dr Seamas Lehane and Dr Ibraham Eyad.