“Oxygen is easy. Just give everyone 100%, and you can’t go wrong.” How many of us have heard or said this? We’ve reinforced this with testing and quality improvement programs that reward this standard of care almost without question. This philosophy has taught several generations of EMS providers to blindly apply non-rebreather masks to every patient they think may possibly need oxygen (O2).
As with many of our “time-tested” therapies, science is now calling this practice into question.1 EMS educators must stress the fact that oxygen is a drug and can be harmful. This is easy to do with new EMS students because they haven’t been indoctrinated with the philosophy of “more is better.” But how do we convince seasoned providers to give O2 the same respect they give other drugs, such as analgesics? We do what we’ve done with many emergency responder skills–go back to the basics and learn things we thought we already knew.
The Theory
Oxygen is listed in the U.S. Pharmacopeia (USP) alongside all the other medications carried by prehospital providers.2 So instructors should teach EMS students about oxygen with the same vigor they’d use for any other medication at the provider’s disposal.
Start by educating that O2 has indications, contraindications, side effects and dosing requirements. Doing so stresses that patient assessment and findings must drive our care to prevent patient harm. Using the time-tested mantra of the “five Rs” (right drug, right dose, right route, right patient and right time) when applying oxygen will also demonstrate the same serious thought as giving an injection of a medication through an IV. Repetitive learning techniques, such as drug flash cards and quiz games, will help students memorize these basic but important points.
At this point, instructors should also explain why we give oxygen to patients. This begins with understanding what our bodies use O2 for and most importantly, how the body regulates the amount it takes in. Instruction should include information about respiratory drives and some basic cellular metabolism, so even the most basic provider can build the knowledge foundation needed to understand how oxygen is used in the body.
The Practice
Just as we teach using a subjective and objective assessment to evaluate a patient’s pain and the effects/side effects of an analgesic medication, we can do the same with oxygen therapy.
We determine pain levels, visualize injury, and assess age, size, history and vitals to determine the proper type, dose, route and effect of analgesia. We need to use the same criteria for O2 therapy. If a patient is oriented and doesn’t feel dyspnea, doesn’t have shortness of breath and doesn’t have physical findings or changes in vital signs that indicate hypoxia, then they probably don’t need supplemental O2. However, patients with certain physical complaints, such as acute coronary syndrome or cerebrovascular accident symptoms, may benefit from an enhanced level of oxygen in short-term prehospital therapy.3
Instructors could consider comparing O2 therapy to immobilization. EMS providers wouldn’t immobilize an arm that has no deformity, pain or other physical trauma. Due to certain mechanisms of injury, however, we may perform spinal immobilization on a patient showing similar negative subjective and objective findings. Illustrate to your students that prehospital providers don’t treat every patient exactly the same in every situation, so EMS providers must use those same clinical-judgment skills with oxygen therapy.
Measurement
EMS has one big advantage with O2 therapy: a meter to help determine its deficit and the effect of its administration. Pulse oximetry (SpO2) has become part of the standard vital signs taken in prehospital and many other healthcare arenas. Evolving from a large desktop machine to devices no larger than a standard wrist watch, use of this tool has become commonplace.
Anyone can now purchase an SpO2 monitor at local pharmacies, and most chronic respiratory disease patients routinely use them at home. When teaching the assessment of SpO2, it’s important to emphasize application and assessments to ensure an accurate reading. Without extenuating circumstances, such as carbon monoxide (CO) poisoning present, SpO2 must be a critical determining factor in O2 therapy.
One way to explain this might be to have your students remember the phrase “95 is enough.” If their patient has no subjective or objective findings to indicate the need for oxygen and the SpO2 is at least 95%, then the administration of this drug isn’t indicated. But note that in some chronic respiratory patients, 95% may be too high and saturations in the 88—92% range may be adequate.1 Education about this variance can demonstrate to providers that a good history is essential in determining the best care. For example, an EMS provider wouldn’t give a patient an injection of epinephrine simply because that patient was stung by a bee and had no other subjective or objective indications.
An experienced provider may say, “Well if 95% is good, then 100% is better, right?” This is the mind-set educators must change, and a good way to break this mind-set is to use the example of a CO survey monitor. Most fire department CO monitors will display a maximum value of 999 parts per million. If the meter alerts, it indicates a large, dangerous amount of CO is present in the atmosphere, but the provider doesn’t know exactly how much.
The same can be said for a SpO2 reading of 100%. An EMS provider knows the red cells are saturated, but they don’t truly know the amount of arterial oxygen (PaO2) present. PaO2 can be assessed only with an arterial blood gas measurement. High PaO2 levels created in the prehospital environment have been shown to cause harm in certain patients and cause changes in partial pressure CO2 and pH.1
So flooding the patient with oxygen can do harm just as much as an analgesic can cause respiratory depression and hypotension. The SpO2 reading of 100% isn’t helpful in determining whether an overdose is occurring. In fact, in many cases of high-oxygen therapy, it probably is. Instructors should also emphasize that a patient who’s complaining of dyspnea and showing other signs of hypoxia must be treated with the appropriate level of O2.
Storage, Usage & Safety
EMS students may know the why and when, but they can’t forget the how and hazards of O2 therapy. Oxygen is considered a hazardous substance and must be properly labeled. It also has a materials safety data sheet (MSDS) that would be appropriate to share with your students.4
One of my first lessons on how not to teach by bad example involved oxygen and my first EMT class. The instructor held a lit cigarette (it was 1981) in front of an oxygen tubing to give us a visual on how it sped up combustion. Unfortunately, he held it far too close, and the plastic tubing caught fire. Before he could turn off the flow, the tubing had burned back to the regulator.
Please do not try this at home. Instead, review all the physical properties, hazards and regulations involved in O2 storage, transportation and use. Explain standard operating procedures with students in detail and possibly use some accident case studies available online to illustrate the hazards.
Perhaps your community has a bulk gas supplier and the supplier could provide additional information or recommend an expert to help with this topic. As an instructor, emphasize the proper technique for installing and removing a regulator. Fires have resulted from the improper installation of regulators on oxygen tanks.5
Also keep in mind that many experienced providers don’t close tank valves and “bleed off” regulators after use. This constant pressure can cause wear and malfunction of the regulator. Include these facts in the psychomotor training on O2 therapy and after practical scenarios.
Ambulance oxygen systems require educators to examine the safety aspects of maintenance. Providers have been injured while changing an ambulance’s inboard cylinder because of weight, space and lifting angles. Conduct a practical demonstration that shows proper handling techniques and safety devices, such as specially designed cylinder loading devices, to help prevent provider injury and equipment damage. A technician or material from your ambulance manufacturer can provide specific details on working with the inboard oxygen system as well.
Advanced training on O2 delivery could include such topics as extending the time a cylinder will last in a given situation. This is especially helpful during rural or wilderness situations that have long patient contact and limited supplies. For another advanced topic, explain setting up mass-oxygen-delivery systems for mass-casualty incidents. Or adapt delivery systems to challenge experienced providers. Using group discussions and other alternative deliveries gives the EMS student a chance to share ideas they have and let everyone learn a new technique. But be sure to guide this discussion so the ideas are safe and meet the necessary standards.
Summary
O2 is used on many EMS calls every day, but new studies and standards show it’s overused and overdosed by EMS providers.1,2 One reason may be a lack of education or emphasis on O2 as a drug, which could cause providers to not treat its use with the same caution and due diligence as other medications.
It should be our goal as educators to raise the assessment and use of O2 to its appropriate level. This will allow students to develop a treatment plan for each patient that’s appropriate for that patient and not based on habit. Oxygen also has unique storage and administration challenges like no other drug we administer. Addressing these challenges requires a mixed delivery of didactic and psychomotor skills to properly convey the safety and efficiency needed for this common but unique drug. JEMS
References
1. New A. Oxygen: Kill or cure? Prehospital hyperoxia in the COPD patient. Emerg Med J. 2006;23(2):144—146.
2. The United States Pharmacopeial Convention. 2011. About USP. In U.S. Pharmacopeia. Retrieved, Oct. 4, 2011, from www.usp.org/aboutUSP.
3. O’Connor R, Brady W, Brooks S, et al. 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care Science. Part 10: Acute coronary syndromes. Circulation. 2010;122:S787—817.
4. Chemical Safety Associates Inc. May 5, 2008. Material Safety Data Sheet. In Chemical Safety Associates Inc. Retrieved Oct. 4, 2011, from http://v2010.raesystems.com/~raedocs/Documentation/MSDS/MSDS-50007_O2.pdf.
5. U.S. Department of Health and Human Services. Dec. 2, 2010. FDA and NIOSH Public Health Notification: Oxygen Regulator Fires Resulting from Incorrect Use of CGA 870 Seals. In U.S. Food and Drug Administration. Retrieved Oct. 4, 2011, from www.fda.gov/MedicalDevices/Safety/AlertsandNotices/PublicHealthNotifications/ucm062088.htm.
This article originally appeared in December 2011 JEMS as “No Clue about O2: Teaching oxygen therapy to prehospital providers.”
