Oxygenation: Acute Respiratory Distress Syndrome (ARDS)
Nursing: A Concept-Based Approach to Learning Volume One, Fourth Edition
Module 15: Oxygenation
Copyright: © 2023, 2019, 2015 Pearson Education, Inc. All Rights Reserved
Course Competencies
Course Learning Outcomes
Outcome 4: Optimize the use of nursing judgment when developing the plan of care.
Outcome 6: Manage a plan of care by anticipating needs identified by relevant trends in patient data.
Outcome 12: Integrate novel approaches to improve safety and quality of care for patients, families, and communities.
Specific Criteria
4.1: Practices appropriate nursing judgment in emergent situations.
4.2: Prioritizes information when making nursing judgments.
6.1: Implements the care plan to meet priority client needs.
12.2: Explores causes to problems affecting healthcare.
Exemplar Learning Outcomes 15.A
Focus Areas
Analyze acute respiratory distress syndrome (ARDS) as it relates to oxygenation.
Description of pathophysiology of ARDS.
Description of the etiology of ARDS.
Summary of risk factors for ARDS.
Comparison of methods for preventing ARDS.
Identification of the clinical manifestations of ARDS.
Summary of diagnostic tests and therapies utilized by interprofessional teams in collaborative care for ARDS.
Differentiation of care for patients with ARDS across the lifespan.
Application of the nursing process to provide culturally competent care for individuals with ARDS.
Overview of Acute Respiratory Distress Syndrome (ARDS)
Definition: ARDS is characterized by a rapid onset of non-cardiac pulmonary edema, progressive refractory hypoxemia, extensive lung tissue inflammation, damage to small capillaries, injury to alveoli, sudden onset, and rapid deterioration of arterial blood gases (ABGs) leading to hypoxemia, hypoxia, and respiratory failure.
Recognizing Cues - Pathophysiology
Primary Insult: Triggers release of chemical mediators leading to damage of the alveolar-capillary membrane.
Pathway of Damage:
Damage to alveolar-capillary membrane.
Interstitial edema occurs followed by alveolar edema.
Damaged surfactant-producing cells lead to a decrease in surfactant production.
Results in decreased lung compliance, atelectasis, and formation of hyaline membranes.
Increased work of breathing and impaired gas exchange lead to respiratory failure.
Recognizing Cues - Etiology
Incidence:
Nearly 200,000 Americans affected by ARDS annually.
Affects individuals of all ages.
Mortality Rate: Ranges from 25% to 45%, with variability based on demographics:
Greater in men than women.
Greater in African Americans.
Worse outcomes in patients with ARDS developed from sepsis compared to those from pulmonary infections or trauma.
Recognizing Cues - Risk Factors
Direct Insults
Pneumonia.
Aspiration of gastric contents.
Inhalation injuries.
Near drowning.
Indirect Insults
Sepsis.
Major burns.
Drug overdoses.
Pancreatitis.
Recognizing Cues - Prevention
Strategy: Determined by identifying risk factors. It is critical to initiate timely interventions to mitigate risk.
Recognizing Cues - Clinical Manifestations
Initial Signs (1-2 days post-insult)
Dyspnea and tachypnea are early signs.
Baseline laboratory data assists in identifying changes in pulmonary status.
Chest x-ray and ABGs may appear normal at initial stages.
Progressive Respiratory Distress
As respiratory distress develops:
Increased respiratory rate, intercostal retractions, and use of accessory muscles.
Persistent tachypnea as demand for oxygen rises.
Development of rales and rhonchi; cyanosis does not improve with oxygen therapy.
Chest x-ray reveals interstitial changes and patchy infiltrates.
Pulse oximetry and ABG levels indicate refractory hypoxemia.
Symptoms of agitation, confusion, and lethargy can occur.
Take Action - Collaboration
Healthcare Team Includes:
Nurses.
Respiratory therapists.
Dietitians.
Physical therapists.
Physicians.
Nurse’s Focus: Constant monitoring of the patient’s condition and responsiveness to subtle cues indicating changes, with timely interventions.
Take Action - Diagnostic Tests
Key Diagnostic Tests:
Arterial Blood Gas (ABG) analysis to determine oxygen and carbon dioxide levels in blood.
Chest x-ray or chest CT scan to evaluate fluid in the lungs.
Complete Blood Count (CBC), blood chemistry, and blood cultures to determine causative factors of ARDS.
Sputum cultures to determine the cause of infection.
Take Action - Pharmacologic Therapy
No Definitive Drug Therapy for ARDS:
Nitric Oxide and Prostacyclin:
Improves vasodilation in pulmonary vasculature, decreases pulmonary vascular resistance, and aids in oxygenation.
Surfactant Therapy.
Corticosteroids:
Their use is controversial but may decrease multi-organ dysfunction and reduce the need for prolonged ventilatory support when administered early in moderate to severe ARDS.
Artificial Airways (1 of 2)
Types of Airways
Oropharyngeal Airways:
Stimulate the gag reflex.
Appropriate only for semiconscious or unconscious patients.
Nasopharyngeal Airways:
Generally tolerated by alert patients.
Require frequent oral and nasal care.
Artificial Airways (2 of 2)
Endotracheal Tubes
Used in patients under general anesthesia or within emergency contexts.
Insertion requires specialized training.
Mouth is the preferred site due to lower risk of infection.
Tracheostomies
Used for long-term airway support, involves creating an opening in the trachea through the neck.
Can be placed in the ER, critical care units, or during surgical procedures.
Nursing Care:
Ensure airway patency, tracheostomy care, and humidity precautions.
Ventilatory Support (1 of 5)
Cornerstone of Management: Mechanic ventilation strategies are developed to be lung-protective.
Types of Ventilators
Negative Pressure Ventilators:
Create external negative pressure to induce inhalation.
Positive Pressure Ventilators:
Push air into lungs, forcing alveoli to expand during inhalation.
Noninvasive Positive Pressure Ventilation (NIPPV):
Administered via mouthpiece, nasal, face, or helmet mask, may prevent the need for tracheal intubation.
Ventilatory Support (2 of 5)
Modes of Ventilation with Positive-Pressure Ventilators
Modes Include:
Continuous Positive Airway Pressure (CPAP).
Bilevel Ventilator (BiPAP).
Assist-Control Mode Ventilation (ACMV).
Intermittent Mandatory Ventilation (IMV).
Synchronized Intermittent Mandatory Ventilation (SIMV).
Positive End-Expiratory Pressure (PEEP).
Pressure-Support Ventilation (PSV).
Pressure-Control Ventilation.
Airway Pressure-Release Ventilation (APRV).
Note: Mechanical ventilation does not cure ARDS; however, it provides necessary ventilation and oxygenation for patients in acute and chronic respiratory distress.
Ventilatory Support (3 of 5)
Ventilator Settings
Key Parameters:
Rate: Generally set for most adults at 12-15 ventilator breaths per minute initially.
Tidal Volume: Amount of gas delivered with each breath, typically 8-10 mL/kg body weight; a low tidal volume of 6 mL/Kg is used to prevent lung injury.
Example Calculation: For a 200 lb patient, convert weight to kg: 200 lbs / 2.2 = 91 kg then 91 kg X 6 mL/kg = ?? (further calculation is needed)
Oxygen Concentration: Percentage of oxygen delivered, typically set between 21% (room air) to 100%.
Additional factors include flow rate, sensitivity, and pressure limit.
Ventilatory Support (4 of 5)
Complications Related to Mechanical Ventilation
Potential Complications:
Ventilator-Associated Pneumonia (VAP).
Barotrauma.
Pneumothorax.
Cardiovascular effects.
Gastrointestinal effects.
Assessment Mnemonic: DOPE (Displacement, Obstruction, Pneumothorax, Equipment failure).
Ventilatory Support (5 of 5)
Weaning from Ventilator Support
Process of gradually reducing mechanical ventilator support to allow the patient to breathe independently.
Factors Affecting Weaning
Preexisting lung conditions.
Duration of mechanical ventilation.
Patient's overall physical and psychological condition.
Constant assessment of vital signs, oxygen saturation, and ABG analysis to predict readiness for weaning.
Use of T-piece or CPAP may assist in weaning.
A primary use for PSV is in cases where long periods of ventilation necessitate respiratory muscle reconditioning.
Terminal weaning is indicated when survival without assisted ventilation is not expected.
Take Action - Nutrition and Fluids
Nutritional interventions should commence 12 to 24 hours post-admission.
A nutrition expert should calculate caloric needs.
Implementation of enteral feedings is essential, with parenteral feeding as a secondary option if necessary.
Take Action - Other Clinical Therapies
Key Interventions Include:
Prone positioning alongside mechanical ventilation to improve oxygenation.
Treatment of any underlying infections with intravenous antibiotics.
Administration of low-molecular-weight heparin to prevent blood clots.
Nursing Process
Continuous and careful monitoring of airway, breathing, and circulation status is vital.
Changes in level of consciousness (LOC), oxygenation, and perfusion necessitate rapid nursing interventions.
Assessment
Observation and Patient Interview
Review of previous respiratory alterations, illnesses, or surgeries within the last 3-4 days that may relate to ARDS.
Physical Assessment Components
Evaluation includes respiratory rate and rhythm, auscultation of lung sounds, assessment of LOC, baseline vital signs, and evaluation of peripheral perfusion.
Diagnosis
Problems Associated with ARDS Patients
Potential for confusion.
Impaired airway clearance.
Ineffective breathing patterns.
Inadequate spontaneous ventilation.
Inadequate gas exchange.
Decreased cardiac output.
Poor response to ventilatory weaning.
Fluid volume excess.
Undernutrition.
Risk for infection.
Acute pain.
Anxiety.
Planning
Goals of Care for Patients with ARDS
Patient achieves orientation to name, place, and time during every interaction.
Normal breath sounds, respiratory rate, and rhythm.
Adequate hemoglobin and hematocrit levels.
Adequate ventilatory support.
Effective removal of secretions.
Normal temperature and WBC levels.
Maintenance of adequate cardiac output, with stable blood pressure, heart rate, and cardiac rhythm.
Adequate nutritional intake.
Pain levels no greater than 3 on a scale of 0 to 10.
Implementation (1 of 9)
Common Nursing Interventions
Assess neurologic status every 4 hours.
Evaluate lung sounds every 2 to 4 hours.
Administer bronchodilators and anticholinergics as needed.
Perform suctioning every 2 hours.
Monitor signs of increased work of breathing or use of accessory muscles.
Measure hourly oxygen saturation via pulse oximetry.
Regularly monitor ABGs.
Auscultate heart rate and rhythm, assess peripheral pulses every 2 hours, and review laboratory data.
Assess renal status and monitor glomerular filtration rate, BUN, and creatinine levels.
Corticosteroids may also be administered as prescribed.
Implementation (2 of 9)
Continuing Nursing Interventions
Administer anxiolytics to mitigate anxiety, restlessness, and agitation.
Prone positioning as indicated.
Elevate head of bed to high-Fowler position.
Continually evaluate color, consistency, and amount of urine every hour.
Ensure stable clinical and hemodynamic status.
Implementation (3 of 9)
Maintaining Patent Airway
Auscultate lung fields every 2 to 4 hours to monitor patency.
Reposition patients every 2 hours as needed.
Ensure adequate hydration and humidification is in place.
Implement chest physiotherapy as indicated.
Perform suctioning as needed and assess the color, consistency, and odor of secretions; sputum samples should be collected for culture and sensitivity testing.
Measure oxygen saturation every hour.
Implementation (4 of 9)
Promoting Spontaneous Ventilation
Maintain the head of bed elevated at 20 to 30 degrees to facilitate breathing.
Repositioning should be done every 2 hours.
Continuously monitor ABGs and pulse oximetry readings.
Provide measures that promote rest and conserve energy.
Administer supplemental oxygen as needed to improve oxygenation.
Implementation (5 of 9)
Enhancing Cardiac Output
Assess LOC at least every 4 hours for any alterations.
Monitor Mean Arterial Pressure (MAP), ensuring systolic BP is above 90.
Evaluate respiratory status and auscultate lung fields every 4 hours.
Regularly evaluate cardiac rhythm and investigate for dysrhythmias.
Monitor intake and output, daily weights for fluid balance assessment.
Assess non-verbal pain cues and administer appropriate medications as prescribed.
Implementation (6 of 9)
Monitoring for Poor Ventilator Weaning Response
Identify signs indicative of dysfunctional weaning:
Increased work of breathing and difficulty breathing.
Increased anxiety and restlessness.
Decreased pulse oximetry levels.
Elevated blood pressure, heart rate, and respiratory rates.
Decreased breath sounds; presence of wheezing and crackles.
Increased reliance on abdominal and accessory muscles.
Decreasing pH levels and elevated PaCO2 levels.
Pale, diaphoretic skin and altered LOC.
Implementation (7 of 9)
Interventions for Weaning Response Issues
Frequent assessment of vital signs every 15-30 minutes, as well as oxygen saturation levels.
Position patient upright (Fowler or High-Fowler) to ease breathing.
Encourage having family members present.
Monitor for signs of ineffective breathing and reassure the patient that nurses are available nearby.
Minimize physical activities during the weaning process.
Provide a safe, comfortable environment conducive to recovery.
Evaluate the patient’s readiness for weaning.
Withhold opiates and sedatives during weaning processes.
Introduce supplemental oxygen post-weaning, as necessary.
Collaborate on oral hygiene practices to reduce dry mouth and discomfort.
Implementation (8 of 9)
Alleviating Anxiety
Encourage patients to express their concerns.
Clearly explain all equipment and any procedures that will be performed.
Outline alternative communication methods post-intubation.
Ensure the patient feels attended to and that nurses are nearby for help.
Provide meaningful explanations to significant others and family members of the critical care situation.
Foster a calm, supportive environment.
Encourage frequent family visits to bolster support.
Promptly attend to physical and emotional needs to reduce anxiety.
Reassure patients of the temporary nature of mechanical ventilation.
Implementation (9 of 9)
Preparing for Discharge
Provide necessary referrals for home health and respiratory care services.
Refer patients to occupational therapy or counseling if added support is needed.
Educate the patient about ARDS:
Importance of adjusting activities until full respiratory function is regained.
Advising against smoking and exposure to smoke or other pollutants.
Recommend pneumococcal and influenza vaccinations to prevent infections.
Lifespan Considerations (1 of 3)
Children
ARDS has a low incidence but may be underdiagnosed.
Immunocompromised children are at higher risk.
Clinical guidelines vary from adults due to unique physiological characteristics such as compliant chest walls and higher baseline airway resistance.
Use of inhaled nitric oxide, exogenous surfactant, and corticosteroids is not routinely recommended; caution in using intubation unless absolutely necessary.
More research is needed to better understand pediatric ARDS management.
Lifespan Considerations (2 of 3)
Pregnant Women
Incidence rates of ARDS in pregnancy are low, but outcomes can be devastating, with maternal mortality rates as high as 9% due to causes such as:
Preeclampsia.
Amniotic fluid embolism.
Obstetric hemorrhage.
Sepsis stemming from infections of the uterus or kidneys.
Influenza during pregnancy.
Management: Goals focus on ensuring adequate ventilation and nutritional support while maintaining close fetal monitoring and using prone positioning cautiously, especially in later trimesters.
Lifespan Considerations (3 of 3)
Older Adults
Older adults, especially those over age 70, are at a greater risk of developing ARDS. This is attributed to age-related physiological changes, resulting in higher mortality rates.
Older adults are often less likely to be admitted to intensive care units (ICUs) and receive less intensive care compared to younger patients.
They are significantly more likely to die from complications related to multiple organ failures.
Implementing treatments aimed at preventing non-pulmonary organ complications can improve overall patient outcomes.
Nutrition plays a vital role, emphasizing a diet rich in omega-3 and omega-6 fatty acids to support lung function and overall health.
Evaluation
Expected Patient Outcomes
Attained and maintained effective airway management.
Oxygen saturation levels maintained above 90%.
Stable cardiac output throughout treatment.
Successfully weaned from mechanical ventilation.
Absence of aspirations of gastric contents.
Normal ABG results.
The patient effectively utilized coping mechanisms to manage anxiety surrounding their situation.
The patient exhibits understanding of the need to avoid secondhand smoke and other pollutants.
If any intervention fails, the nurse must work collaboratively with the interprofessional team to implement new nursing interventions and assist with any necessary procedures.