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Oxygen Management (RN, LPN)

2 Contact Hours including 2 Advanced Pharmacology Hours
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This peer reviewed course is applicable for the following professions:
Licensed Practical Nurse (LPN), Licensed Vocational Nurses (LVN), Nursing Student, Registered Nurse (RN), Respiratory Therapist (RT)
This course will be updated or discontinued on or before Saturday, November 30, 2024

Nationally Accredited

CEUFast, Inc. is accredited as a provider of nursing continuing professional development by the American Nurses Credentialing Center's Commission on Accreditation. ANCC Provider number #P0274.


Outcomes

≥92% of participants will know best practices for oxygen delivery.

Oxygen (O2) commonly treats medical conditions with poor tissue and arterial oxygenation. This course examines the clinical recommendations for using O2 therapy in different disease conditions.

Objectives

After completing this continuing education course, the participants will be able to meet the following objectives:

  1. Explain the various options in oxygen therapy delivery.
  2. Compare and contrast the practice recommendations for oxygen therapy indications in special diagnoses and presentations.
  3. Analyze practice recommendations for oxygen therapy initiation.
  4. Outline the monitoring, dispensing, and documentation requirements for oxygen therapy.
  5. Describe oxygen therapy discontinuation practices.
CEUFast Inc. and the course planners for this educational activity do not have any relevant financial relationship(s) to disclose with ineligible companies whose primary business is producing, marketing, selling, re-selling, or distributing healthcare products used by or on patients.

Last Updated:
To earn of certificate of completion you have one of two options:
  1. Take test and pass with a score of at least 80%
  2. Reflect on practice impact by completing self-reflection, self-assessment and course evaluation.
    (NOTE: Some approval agencies and organizations require you to take a test and self reflection is NOT an option.)
Author:    Julia Tortorice (RN, MBA, MSN, NEA-BC, CPHQ)

Oxygen (O2) Therapy

The old practice of specifying a fixed O2 concentration or fraction of inspired O2 is discouraged. The method has no clear target for the therapy, making it hard to plan appropriately for monitoring and weaning when necessary. In emergencies, the lack of a formal O2 prescription should not preclude the administration of supplemental O2. In pre-hospital cases, first responders and medical personnel should administer O2 liberally if required to improve clinical symptoms. However, written documentation, including the duration of emergency administration, O2 concentration, and flow rate, should be made in all emergency medical interventions.

The delivery system is determined by the O2 requirements, breathing pattern, mouth opening, and risk of hypercapnia. Once therapy is initiated, the team should reassess the patient to detect possible signs of clinical deterioration at the early stage of treatment. It is essential in patients with no prior history of supplemental O2 therapy. Early reassessments should also examine the risks of complications or the need for intensive care (Quinten et al., 2018). The reassessment interval should be determined by the severity of vital signs and the extent of hypoxemia. Patients who are started on O2 therapy can be reassessed every 4 to 6 hours. Continuous monitoring may be needed depending on where the treatment was initiated. Regardless of where therapy was initiated, continuous monitoring is recommended if multiple vital signs are outside the normal physiological ranges.

Delivery Systems

Depending on the patient's age, O2 requirements, therapeutic goals, tolerance, and humidification needs, various O2 delivery methods are available for both inpatient and pre-hospital settings. These delivery systems are categorized into two broad classes, low-flow delivery methods, and high-flow delivery methods. The low-flow delivery methods include:

  • Nasal cannula
  • Simple face mask
  • Reservoir face mask

The high-flow delivery methods include:

  • High-flow jet mixing mask
  • Ventilator
  • CPAP/BiPAP
  • High-flow nasal cannula (HFNCs)

These delivery systems allow the administration of inspired supplemental O2 of different percentages. The inspired concentration and the O2 saturation depend on the ventilation minute volume and the flow rate. The high-flow mask systems can deliver an estimated 40 L/min of O2, sufficient enough to meet the saturation level target in many inpatient settings. At this rate, the systems ensure the breathing pattern does not affect the fraction of inspired oxygen (FiO2) as the delivery flow rate exceeds the physiological respiratory rate. With both the high-flow and low-flow delivery options, the most widely used in O2 therapy include the following below.

Nasal Cannulas

Nasal cannulas are simple and convenient for long-term O2 therapy use in patients. The O2 flow rate (1-6 L/min) varies with the ventilation minute volume that determines the FiO2. When the O2 flow rate achieves a 2 L/min delivery, the O2 in the hypopharynx amounts to 25% to 30%. As with rebreathing-type masks, nasal cannulas are convenient for long periods of use and can be used while eating or talking. Local irritation and dermatitis may occur in patients using nasal cannulas long-term.

Simple O2 Mask

O2 masks cover the nose and mouth. The simple mask is a low-flow mask that delivers O2 moderately at a flow range of 6-10 L/min, achieving an O2 concentration of 40%-60%. These masks have exhalation ports on the sides, allowing carbon dioxide to escape and mix with room air. They are used primarily in type 1 respiratory failure cases requiring supplemental O2, including pulmonary embolus and pulmonary edema. A technical disadvantage of this mask is its low flow rate, allowing the possibility of significant rebreathing as air is poorly flushed from the face mask. Low-flow masks make it difficult to achieve a low inspired O2 concentration.

Reservoir Masks

A partial re-breather mask has a single two-way valve that connects the mask to the reservoir bag: The two-way valve enables about one-third of the exhaled breath to escape through the exhaust tube.

Figure 1: Reservoir Bag

photo of a resevoir bag

A non-re-breather mask has a one-way valve that prevents exhaled air from entering the tubing or a bag containing the O2 to be inhaled. Instead, the exhaled air escapes through one-way rubber stoppers in the mask. The rubber stoppers prevent the patient from inhaling any room air. When the patient inhales, the one-way valve opens to deliver 60 to 80% O2 concentration. A re-breather mask is for serious conditions, such as patients with serious trauma injuries or carbon monoxide poisoning.

High-Flow Jet Mixing Masks

High-flow jet mixing masks are suitable for delivering low O2 concentrations (24-35%) in a high flow. In patients with an unstable breathing pattern, these masks provide a ventilatory requirement unaffected by the breathing pattern. Consequently, the flow rate and O2 concentration can be easily modified to achieve target saturation levels quickly. In patients with COPD and respiratory failure, high-flow jet mixing masks reduces the risk of carbon dioxide retention and improve the clinical symptoms of hypoxemia. With a high-flow delivery system, rebreathing of gas is not considered a significant problem.

High-Flow Nasal Cannula (HFNCs)

The concentration of O2 administered and the flow rate of delivery are considered primary factors in the evaluation of the effectiveness of an O2 therapy protocol. A study focused on nasal high-flow O2 therapy in patients with hypoxia and reported how the effective inspiratory O2 concentration depends on the patient's respiratory flow and breathing pattern (Schwabbauer et al., 2014). As with this study, other studies on supplemental O2 therapy have consistently explored nasal high-flow O2 therapy in conditions requiring O2.

In high-flow O2 therapy, humidified O2 is heated and delivered using specially-designed nasal cannulas capable of providing supplemental O2 at a rate of 40-60 L/min. HFNCs deliver O2 at a rate higher than the patient's physiological respiratory flow. Consequently, a defined fraction of O2 in inspired air is delivered, independent of the patient's breathing pattern. In addition to rapidly boosting the saturation state, HFNCs also reduce respiratory discomfort and the work of breathing, and the risk of damage to the respiratory epithelium. HFNCs are now widely used in intensive care units.

In a systemic review of a randomized-controlled quasi-experimental study, Marjanovic et al. (2020) compared high-flow O2 therapy versus conventional O2 therapy in patients with acute respiratory failure admitted to the emergency department. The researchers indicated that high-flow O2 decreased dyspnea and the respiratory rate in the study population (Marjanovic et al., 2020). In another systematic review conducted by Ou et al. (2017), study results indicated that the reintubation rate of critically ill patients was lower when high-flow O2 was used compared with conventional O2 delivery methods (Ou et al., 2017). High-flow O2 also shortens hospital stays and lowers the intubation rate in immunosuppressed patients with acute pulmonary failure (Wen et al., 2019).

Rebreathing and Anesthetic O2 Mask

Rebreathing masks are also called bag valve masks or artificial manual breathing unit (Ambu) bags. Although not commonly used, these masks provide supplemental O2 concentrations greater than 60%. The design incorporates non-rebreathing valves and reservoir bags. The tight-fitting mask can achieve 100% O2 if used in cardiac or respiratory arrest patients. The only contraindications for use are O2 toxicity risks and prolonged use.

Figure 2: Ambu bag

photo of an Ambu bag

Humidification

Humidified O2 is not required in low-flow O2 delivery and short-term high-flow O2 administration courses (Calligaro et al., 2020). Therefore, humidified O2 is not needed in pre-hospital settings. It is reasonable to use humidified O2 in cases of upper respiratory discomfort due to dryness and in patients who require high-flow O2 therapy for an extended period. Humidified O2 can also be used in patients with an artificial airway requiring long-term O2 management.

Clinical studies highlight the benefits of humidified O2 in patients with viscous secretions. The decision to use humidified O2 in the therapy course should be made individually. The practitioner must critically examine the risk and benefits of such a decision since the clinical evidence supporting humidified O2 therapy is insufficient to recommend wide use. Poiroux et al. (2018) published a study investigating the effects of dry versus humidified O2. The study could not demonstrate that non-humidified O2 was less effective in these patients than humidified O2 after 6–8 hours of therapy.

O2 Therapy Initiation

In emergencies, administer O2 empirically without a formal prescription to restore airflow. The lack of formal O2 prescription should not restrict O2 administration in a formal setting. The O2 concentration, the flow rate, the adjustment, and the patient's response should be documented. In a pre-hospital setting or for patients under ambulatory care, O2 saturation levels should be monitored until the patient's vitals are stable and a specialist does a full assessment. The concentration of O2 administered should be adjusted upwards or downwards to maintain the appropriate saturation range.

In acutely ill patients presenting for clinical intervention, O2 therapy (if indicated) should be aimed at maintaining a patent airway. In patients with cardiac arrest, respiratory distress, or respiratory arrest, administer O2 empirically. The American College of Chest Physicians and the National Heart, Lung, and Blood Institute recommend a list of conditions to classify clinical conditions requiring empirical initiation of O2 therapy. These conditions include:

  • Cardiac and respiratory arrest
  • Hypoxemia (PAO2<7.8 kPa, SaO2<90%)
  • Hypotension (systolic blood pressure < 100 mmHg)
  • Low cardiac output and metabolic acidosis (bicarbonate < 18 mmol/l)
  • Respiratory distress (respiratory rate > 24/min)

Nurses are expected to recognize the clinical signs of inadequate tissue oxygenation. The pathophysiological mechanisms resulting in low tissue oxygenation are broadly categorized into two groups. The two groups include those impairing the O2-hemoglobin complex system and those causing arterial hypoxemia. Recognizing these mechanisms requires careful patient evaluation. However, more than one mechanism may contribute to poor tissue oxygenation in the same patient.

The pathophysiological mechanism grouped under the failure of the O2-hemoglobin transport system include:

  • Low hemoglobin concentration
  • Poor tissues perfusion rate
  • Hemoglobinopathies, high carboxyhemoglobin concentration, and other conditions implicated in the abnormal O2 dissociation curve
  • Histotoxic poisoning of the intracellular enzymes, including cyanide poisoning, paraquat poisoning, and septicemia.

In arterial hypoxemia, the pathophysiological mechanisms implicated include:

  • Right to left shunts
  • Low-inspired O2 partial pressure
  • Alveolar hypoventilation in sleep apnea, opiate poisoning, etc.
  • Ventilation-perfusion mismatch in asthma, atelectatic lung zones, etc.

The clinical symptoms of these pathophysiological mechanisms are nonspecific and can be challenging to recognize quickly. These symptoms include altered mental state, dyspnea, cyanosis, tachypnoea, arrhythmias, and coma. In all patients under evaluation for a possible O2 therapy regimen, arterial O2 saturation (SaO2) and partial O2 pressure (PaO2) measurements are the principal indicators for initiating, prescribing, monitoring, and modifying supplemental O2 therapy.

SaO2 and PaO2 can be normal in some patients presenting with clinical evidence of tissue hypoxemia caused by low cardiac output, anemia, and failure of tissues to use O2. In these cases, mixed venous O2 partial pressure measured in pulmonary artery blood is considered a better tissue oxygenation index because its value approximates to mean partial tissue pressure. The most widely used guidelines in assessing the patient for a possible immediate O2 intervention include the following:

  • Assess the airway and optimize airflow using airway positioning as necessary in the patient. Head tilts, chin lifts, and left lateral tilts might be required.
  • Perform a thorough clinical assessment and documentation at the beginning of every shift, including cardiovascular, respiratory, and neurological system assessments.
  • Check and document O2 equipment setup and any change in patient positioning at the beginning of each shift.
  • O2 flow rate, patency of tubing, and humidifier settings should be checked and documented hourly.
  • Heart rate, respiratory rate, respiratory distress, and O2 saturation, using continuous pulse oximetry, should be checked hourly and recorded.

Special Situations

Patients at Risk of Hypercapnic Respiratory Failure

Some patients require special consideration in O2 therapy. These patients include those with the following:

  • COPD
  • Morbid obesity
  • Cystic fibrosis
  • Chest wall deformities or neuromuscular disorders
  • Fixed airflow obstruction associated with bronchiectasis or other hypercapnic respiratory failure risk factors

These patients depend on a higher-than-normal carbon dioxide level for breathing. Regardless of the respiratory problem, the recommended target O2 saturation range is 88 - 92%. Treatment should be based on ABG results.

Pre-hospital O2 Therapy

Supplemental O2 therapy should aim at a target saturation range of 92 - 96% or 88 - 92% in patients with a high risk of hypercapnic respiratory failure (Kopsaftis et al., 2020). High-dose O2, defined as 100% or 15 L/min, should only be administered if pulse oximetry fails to establish O2 saturation levels in critical conditions.

Critical Illnesses

In critical illnesses, including major trauma, major head injury, sepsis, shock, and anaphylaxis, supplemental O2 therapy should be initiated with a reservoir mask at 15 L/min. In cases of acute seizures due to epilepsy or other causes, high-concentration O2 should be administered until a satisfactory oximetry measurement can be obtained. In carbon monoxide poisoning, an apparently 'normal' oximetry reading may be produced by carboxyhemoglobin. Use a reservoir mask at 15 L/min, irrespective of the oximeter reading and PaO2.

Pregnancy

Supplemental O2 therapy is recommended in pregnant women who suffer from major trauma, sepsis, or acute illness. During labor, supplemental O2 can be administered to women with underlying hypoxemic conditions. A left lateral lift or manual uterine displacement should be considered in pregnant women above 20 weeks of gestational age presenting with a high risk of developing associated cardiovascular compromise. Positioning on the left relieves pressure on the aorta. Positioning eliminates the risk of aortocaval compression. A full lateral positioning can also be considered.

Supplemental O2 should only be initiated during labor when there is clinical evidence of maternal hypoxemia, defined as an O2 saturation level of less than 94%. There is little evidence supporting supplemental O2 therapy in intrauterine fetal resuscitation. There is also no clinical evidence of harm to the fetus if O2 is initiated for an extended period in uncomplicated labor.

Neurological Disorders

Urgent medical assessment and clinical intervention are required in patients at risk of respiratory failure due to neurological disorders. The initial evaluation is focused on the level of risk and a possible need for non-invasive or invasive ventilator support rather than O2 therapy. O2 saturation level monitoring in these patients is done with spirometry and blood gases.

In morbidly obese patients with a body mass index (BMI) greater than 40 kg/m2, O2 supplementation should be initiated and maintained at a target saturation range of 88 - 92%. These patients are at risk of hypoventilation even if they present with no clinical evidence of obstructive sleep apnea. Hypercapnic patients with comorbidities should be considered for non-invasive ventilation (Davidson et al., 2016).

Perioperative Care and Conscious Sedation

O2 supplementation is recommended in all surgical procedures requiring short-term or long-term conscious sedation. The guideline recommends periodic monitoring of O2 saturation levels using pulse oximetry during the procedures and the recovery phase. Periodic monitoring is beneficial when surgery is performed in patients with hypercapnia and SaO2 reduction.

Arterial oxygenation reduction is considered one of the major complications in many perioperative care plans. In the case of a significant decrease in arterial oxygenation characterized by a SpO2 of less than 90%, supplemental O2 therapy should be initiated as a corrective plan. Patients with cardiorespiratory conditions undergoing procedures are more likely to experience hypoxemia and hypercapnia. The frequency of hypoxemia increases if patients are heavily sedated. Routine O2 administration is not recommended in these patients as it conceals the clinical signs of respiratory failure.

Oximetry should be monitored in patients using patient-controlled analgesia for hypoxemia. The primary clinical aim of O2 therapy in these patients is to maintain a stable O2 saturation level.

Stroke Management

O2 saturation level monitoring is clinically crucial in stroke management as it impacts disease prognosis. Saturation levels should be monitored every four hours in these patients with all episodes of hypoxemia. If hypoxemia develops post-stroke, the practitioner should assess the patient. O2 should only be initiated in severe cases involving airway occlusion after securing airway integrity.

O2 administration in stroke is advised through the nasal route. The recommendation exempts patients with pathological nasal blockage, contraindications to nasal delivery, and patients with a different delivery route showing clear clinical benefits. A high concentration of supplemental O2 should be avoided in stroke management unless this is required to maintain normal O2 saturation.

As in patients with cardiorespiratory conditions, patients managed with supplemental O2 in stroke episodes should be aligned in the best possible upright position. If patients regress into a reduced level of consciousness, this guideline recommends a recovery position with the paralyzed side lowest.

Ventilated Patients

Ventilated patients in the Intensive Care Unit must be monitored closely and placed on supplemental O2. The risk of hypercapnic respiratory failure is minimal under mechanical ventilation. However, there are increasing submissions on the harmful effects of supplemental O2 on ventilated patients (Palmer et al., 2019).

Monitoring, Dispensing, and Documentation

O2 delivery, therapy monitoring, and vital sign documentation are all fundamental requirements in supplemental O2 care (O'Donnell et al., 2019). The British Thoracic Society guideline prescribes a 5-minute periodic check for patients started on O2. The recommendation also includes patients who require an increased O2 concentration and those whose O2 therapy has been stopped. In stable patients responding to therapy, SpO2 and the necessary variables should be monitored at least four times daily. Saturation levels should be monitored continuously in those with an active critical illness. After every episode of therapy change, the new saturation rate, flow rate, and delivery system should be recorded on the patient's chart after 5 minutes.

The German S3 guidelines were developed for National Disease Management Guidelines (AWMF). As the first national guideline on supplemental O2 therapy, the German S3 guideline directly addressed clinical concerns surrounding O2 prescriptions and O2 therapy in disease conditions. The general recommendations adopted as best practice in the German S3 guideline on supplemental O2 use include the following (Gottlieb et al., 2022).

Positioning is considered a fundamental factor in therapy effectiveness. In conscious hypoxemic patients, an upright positioning may improve tissue O2 saturation levels and disease prognosis. Clinical evidence links acute respiratory failure in morbidly obese patients with supine positioning. Pregnant women should be positioned on the left side to reduce the risk of aortocaval compression.

In non-hypoxemic patients in palliative care, nonpharmacological options, including relaxation exercises, cooling of the face, airflow from a table fan, and walking aids, should be considered the primary therapy option. Opioids are effective in the management of dyspnea in non-hypoxemic patients.

Respiratory rate is an important vital sign for a hypoxemic patient on O2 therapy. Pulse oximetry is recommended as a simple, non-invasive method of measuring the SaO2 level in inpatient and outpatient clinical settings. However, pulse oximetry is less accurate than measuring SaO2.

Discontinuation of O2 Supplementation Therapy

On O2 therapy discontinuation, the expert consensus in modern medicine states that O2 delivery should be reduced when a patient is clinically stable, and O2 saturation is above the target range or within the range for several hours. Documented signs of clinical stability in these patients include a normal respiratory rate and stable vital signs. During the short phase of recovery from an acute condition, some patients experience transient hypoxemia. Exercise-induced desaturation has also been reported in patients with acceptable O2 saturations.

Immediately after stopping O2 therapy, the saturation should be monitored. If it is maintained at the target saturation level, a repeat check should be conducted one hour later. In successfully weaned patients with underlying comorbidities, saturation levels and vital signs should be monitored as the patient is managed for these conditions.

If the target saturation level falls after stopping O2 therapy, the weaning attempt is deemed unsuccessful (Rostin et al., 2019). In this case, the O2 therapy is restarted with the lowest O2 concentration maintained in the patient before weaning. Hold steady at this concentration and observe for 5 minutes. If this concentration restores the desired saturation level, continue O2 therapy with this protocol and attempt weaning later. However, the patients must fulfill all the necessary conditions, including stable vital signs, before weaning is initiated later. The practitioner should conduct a thorough clinical review examining the cause of deterioration before starting a new therapy protocol.

Case Study

Amoke is a 45-year-old African American, crushing it hard in her career as the Chief Brand Promoter for Megatron Capital Financing. Her demanding work schedule involves around-the-clock work and travel plans. She had just returned from a trip to Lagos, a metropolis in Africa's biggest economy, Nigeria. The journey to Lagos was largely successful; however, Amoke's 3-weeks extended stay exposed her to the hydrocarbon-polluted air in Lagos.

Two days after the visit, she reportedly fainted while presenting a new brand campaign. She was rushed to a Chicago Hospital and admitted to Emergency Observation Care. On examination, Amoke's first clinical summary documented the following signs and symptoms:

  • Labored breathing
  • Chest pain on inhalation
  • Cramping pain in the trunk region
  • Mild swelling of the calf
  • Periodic gasping
  • Cold extremities and paleness

There was documented long-term drug use. No evidence of strangulation or domestic abuse. No personal or family history of asthma and no documentation of any chronic medical problems. She was reportedly healthy until that morning at the board meeting. She mentioned how her symptoms started during the last few days of her trip. Her vital signs during the first hour of admission include:

  • A heart rate of 125 beats per minute
  • A blood pressure of 190/85 mmHg
  • A surface body temperature of 37.5 degrees Celsius
  • O2 saturation of 87%
  • A respiratory rate of 25 breaths per minute

Her increased heart rate (tachycardia) indicated altered metabolism as the body struggled for oxygenated air and proper lung perfusion. Amoke's resting respiratory rate is higher than the medical standard of 12-20/min for adults. Finally, a low O2 saturation rate of 85% and the complaints of chest pain on inhalation suggest a lung oxygenation problem.

She was unresponsive to repeated Salbutamol 5 mg nebulizer treatments. Her complaints of gripping chest pain increased, and she regressed quickly, becoming unresponsive to sudden touch as her heart rate increased by 9 points. She was given a supplemental O2 regimen. A concentrated O2 regimen was initiated. She was also hooked to an ECG to monitor the heart's electrical activity. A nitroglycerin tab was given for the chest pain.

About 20 minutes later, the supplemental O2 therapy significantly improved her condition. She had pupil dilation in response to light and exhibited a conscious response to gripping touch. Her ECG showed a stable pattern. Her vitals also improved significantly, with her heart rate falling to 85/min and her pulse oximetry O2 saturation increasing to 96%. She was scheduled for a blood test and x-ray imaging for further investigations. Amoke's case is another in a long list of medical evidence suggesting the efficacy of O2 supplementation therapy in inpatient emergency admissions.

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Implicit Bias Statement

CEUFast, Inc. is committed to furthering diversity, equity, and inclusion (DEI). While reflecting on this course content, CEUFast, Inc. would like you to consider your individual perspective and question your own biases. Remember, implicit bias is a form of bias that impacts our practice as healthcare professionals. Implicit bias occurs when we have automatic prejudices, judgments, and/or a general attitude towards a person or a group of people based on associated stereotypes we have formed over time. These automatic thoughts occur without our conscious knowledge and without our intentional desire to discriminate. The concern with implicit bias is that this can impact our actions and decisions with our workplace leadership, colleagues, and even our patients. While it is our universal goal to treat everyone equally, our implicit biases can influence our interactions, assessments, communication, prioritization, and decision-making concerning patients, which can ultimately adversely impact health outcomes. It is important to keep this in mind in order to intentionally work to self-identify our own risk areas where our implicit biases might influence our behaviors. Together, we can cease perpetuating stereotypes and remind each other to remain mindful to help avoid reacting according to biases that are contrary to our conscious beliefs and values.

References

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