Oxygenation: Respiratory Failure and ARDS Notes

Good Samaritan College of Nursing and Health Science NUR 202 Pre-Class Worksheet: Oxygenation

Concept Overview

  • Topic: Oxygenation

  • Exemplars: Respiratory Failure, Acute Respiratory Distress Syndrome (ARDS)

Learning Outcomes

  1. Relate the pathophysiological bases for respiratory failure and ARDS.

  2. Compare assessment findings identified in patients with respiratory failure versus ARDS including diagnostic testing and blood gas analysis.

  3. Prioritize nursing diagnoses and collaborative problems for patients with complex oxygenation needs.

  4. Describe the collaborative management of patients requiring intubation and mechanical ventilation.

  5. Discuss pharmacologic and nutritional therapies for patients with complex oxygenation needs.

  6. Identify evidence-based nursing practice for care of patients with advanced oxygenation needs.

  7. Integrate cultural competence and psychosocial support in providing care for the patient with advanced oxygenation needs, including family support.

  8. Develop a collaborative plan of care for patients with alteration in oxygenation, utilizing community resources for facilitating transition from one level of care to another.

Key Questions and Answers

1. Classification of Respiratory Failure

  • Respiratory failure can be classified based on blood gas abnormalities.

2. Normal Ranges for Arterial Blood Gases (ABGs)

  • pH: 7.35 - 7.45

  • PaO2: 80 - 100 mmHg

  • PaCO2: 35 - 45 mmHg

  • HCO3: 22 - 26 mEq/L

3. Critical Blood Gas Values Defining Respiratory Failure

  • Hypoxemia: PaO2 ≤ 60 mmHg

  • Hypercapnia: PaCO2 > 50 mmHg occurring with acidemia (pH < 7.35) and SaO2 < 90%

4. Hypoxemia Indicator in Acute Respiratory Failure

  • All patients in acute respiratory failure are always hypoxemic, characterized by low arterial blood oxygen levels.

5. Hallmark of Respiratory Failure

  • Dyspnea: Perceived difficulty breathing.

  • Orthopnea: Finding it easier to breathe in a sitting position.

6. Collaborative and Nursing Interventions for Respiratory Failure

  • Oxygen Therapy: Supplemental oxygen to manage hypoxemia.

  • Positioning: Use of a semi-Fowler’s position (15-45º) to aid breathing.

  • Coughing and Deep Breathing Exercises (C&DB), Incentive Spirometry (IS), and turning every 2 hours to prevent complications.

  • Anxiety Reduction: Utilize relaxation techniques, diversional activities, and guided imagery.

  • Minimize Energy Expenditure: Encourage minimal self-care and avoid unnecessary procedures.

  • Medication Administration: Systemic or inhaled bronchodilators such as Albuterol (Proventil, Ventolin) for short acting and Servent, Atrovent, Theophylline, Prednisone for long acting.

  • Refer to previous courses (NUR 102) for further details on COPD and asthma management.

7. Definition of Ventilatory Failure

  • Ventilatory Failure: A problem in oxygen intake and blood delivery causing ventilation-perfusion (V/Q) mismatch, where ventilation is inadequate and perfusion is normal. Insufficient oxygen reaches the alveoli, leading to hypoxemia.

8. Common Causes of Ventilatory Failure

  • Intrapulmonary Causes:

    • COPD

    • Pulmonary Embolism (PE)

    • Pneumothorax

    • Pulmonary Edema

    • ARDS

    • Interstitial Fibrosis

  • Extrapulmonary Causes:

    • Neuromuscular Disorders (e.g., Guillain-Barré, Polio, Myasthenia Gravis)

    • Spinal Cord Injuries

    • CNS Dysfunction (e.g., stroke, meningitis, sedatives, opioids)

    • Conditions such as massive obesity and sleep apnea.

9. Definition of Ventilation/Perfusion (V/Q) Mismatch

  • Occurs when perfusion is normal but ventilation is inadequate, indicating that the chest pressure does not sufficiently change for proper air movement.

10. Definition of Oxygenation Failure

  • Oxygenation Failure: Occurs when chest pressure changes are normal and air moves adequately but does not sufficiently oxygenate the pulmonary blood.

11. Common Causes of Oxygenation Failure

  • Listed Causes:

    • Smoke inhalation

    • Carbon monoxide poisoning

    • Pneumonia

    • Congestive Heart Failure (CHF) with pulmonary edema

    • ARDS

    • Abnormal hemoglobin

    • Hypovolemic shock

    • Hypoventilation

    • Complications of Nipride therapy.

12. Causes of Acute Lung Injury (ALI)

  • ALI can result from direct or indirect lung injuries such as:

    • Shock

    • Trauma

    • Pancreatitis

    • Fat and amniotic emboli

    • Sepsis

    • Pulmonary infections

    • Inhalation of toxic gases (e.g., smoke)

    • Pulmonary aspiration

    • Drug ingestion (e.g., heroin, opioid, ASA)

    • Hemolytic disorders

    • Multiple blood transfusions

    • Cardiopulmonary bypass

    • Near drowning (especially in fresh water).

13. Indicators for ARDS

  • Key Indicators:

    • Persistent hypoxemia even with 100% oxygen.

    • Decreased pulmonary compliance.

    • Dyspnea.

    • Non-cardiac associated bilateral pulmonary edema.

    • Dense pulmonary infiltrates on X-ray (ground glass appearance).

14. Nursing Priority in ARDS Risk Patients

  • Priority: Early recognition of patients at high risk for ARDS, specifically focusing on patients:

    • On tube feedings who are not tolerating them (high risk for aspiration pneumonia).

    • With swallowing difficulties or poor gag reflex (high risk for aspiration pneumonia).

    • At risk for developing sepsis (e.g., immunosuppressed patients).

  • Importance of meticulous handwashing.

15. Initial Assessment in ARDS Risk Patients

  • Assessment Focus: Respiratory system.

    • Assess breathing and work of breathing: look for signs of grunting respirations, pallor, cyanosis, intercostal and substernal retractions.

16. Establishing Diagnosis of ARDS

  • Diagnosis confirmed via lowered PaO2 values from ABG, observing that the patient has a progressively higher need for oxygen but does not respond to high concentrations of O2 due to an inflammatory process damaging the alveolar-capillary membrane, causing leakage of fluid into the alveolar interstitial space, thus causing severe dyspnea and hypoxemia.

17. Key Interventions for ARDS Patients

  • Major Interventions:

    • Intubation and mechanical ventilation.

    • Consider sedation and paralysis to adequately ventilate and reduce oxygen needs.

    • Frequent assessment of lung sounds (hourly).

    • Suctioning as needed to maintain airway patency.

    • Keeping Head of Bed (HOB) elevated for comfort.

    • Positioning: adopting a prone position when ordered, implementing kinetic therapy, and facilitating continuous lateral rotation.

  • Important Safety Concern: Avoid dislodgement of the endotracheal tube or tracheostomy.

  • Focus on increasing perfusion and oxygen without overloading the patient.

18. Collaborative Problems Related to ARDS

  • Potential issues may include:

    • Respiratory Failure

    • Pulmonary Edema

    • Pulmonary Fibrosis

    • Oxygen Toxicity

    • Renal Failure

    • Congestive Heart Failure (CHF)

    • Pressure Ulcers

19. Nutritional Therapy in ARDS Patients

  • Nutritional Interventions:

    • Total Parenteral Nutrition (TPN) or Tube Feeding (justification is that patients unable to take food orally need calories and it helps maintain GI tract function).

20. Fluid and Pharmacologic Therapies for ARDS Patients

  • Fluid Management:

    • IV fluids, typically Normal Saline (NS).

  • Medications:

    • Dobutrex (Dobutamine) to increase cardiac output.

    • Vasopressors (e.g., dopamine) to promote vasoconstriction increasing BP and perfusion.

    • Primacor to enhance perfusion through vasodilation in the pulmonary bed.

    • Medication for sedation, analgesia, and antianxiety, stress ulcer prophylaxis, DVT prophylaxis, corticosteroids, diuretics, and antibiotics.

Mechanical Ventilation Considerations

1. Patient Populations for Mechanical Ventilation

  • Indications:

    • Hypoxemia due to pulmonary shunting where other oxygen delivery methods lack efficacy.

    • Patients requiring ventilatory support post-surgery.

    • Patients who struggle with the work of breathing while maintaining adequate gas exchange.

    • Patients under general anesthesia or heavy sedation for diagnostic/therapeutic interventions.

2. Most Common Artificial Airway in Intubation

  • Common Device: Endotracheal Tube (ETT).

  • Confirmation Process:

    • Auscultation of breath sounds.

    • Chest X-Ray is ordered after ETT stabilization.

3. Goals of Mechanical Ventilation

  • Main Goals:

    • Facilitate gas exchange and decrease the work necessary for an effective breathing pattern.

4. Common Collaborative Problems for Intubated Patients

  • Key issues include:

    • Anxiety related to hypoxemia, life-threatening illness, and loss of control.

    • Impaired gas exchange due to disrupted ventilation and perfusion.

    • Fatigue from hypoxemia and systemic inflammation.

    • Sleep deprivation in ICU settings.

    • Nutritional imbalance related to ETT dependency and increased metabolic rate.

    • Risk for injury related to high Fio2 or barotrauma.

    • Potential for ventilator-associated pneumonia.

5. Nursing Priorities for Ventilated Patients

  • Nursing responsibilities encompass:

    • Monitoring and evaluating patient responses.

    • Safe management of the ventilator system.

    • Prevention of complications.

6. Nursing Assessment Responsibilities for Mechanical Ventilator Care

  • Critical assessment functions involve:

    • Monitoring, evaluating, and documenting patient response to ventilation.

    • Regular assessment of vital signs (VS).

    • Hourly auscultation of breath sounds and assessment of ETT placement.

    • Monitoring of pulse oximetry.

    • Verification of the ETT lip line level or centimeter markers for correct placement.

    • Checking for irritation and breakdown around ETT, documenting findings.

    • Pacing and clustering patient care activities to minimize fatigue.

    • Suctioning as required.

    • Anticipating patient's needs and facilitating access to communication tools.

    • Keeping frequently used items accessible and ensuring call light is within reach for patient safety and control.

    • Considering cultural differences and addressing personal biases in care.

7. Definitions of Mechanical Ventilation Terms

  • Assist Control (AC):

    • The mode allows the patient to trigger each breath with preset tidal volume (VT) and respiratory rate (RR).

  • Synchronized Intermittent Mandatory Ventilation (SIMV):

    • A mode featuring preset RR and VT synchronized with spontaneous patient breaths, allowing the patient to breathe on their own between ventilator breaths.

  • Bi-level Positive Airway Pressure (BiPAP):

    • A non-invasive pressure support method typically used for sleep apnea.

  • Tidal Volume (VT):

    • The amount of air delivered with each breath, typically 5 – 8 mL/kg of body weight (average ~400 – 800 mL).

  • Respiratory Rate (RR):

    • The number of ventilator breaths delivered per minute (average ~10 – 14 bpm).

  • Fraction of Inspired Oxygen (FiO2):

    • The concentration of oxygen delivered to patients (35 – 100%).

  • Peak Inspiratory Pressure (PIP):

    • The maximum pressure applied during inspiration.

  • Continuous Positive Airway Pressure (CPAP):

    • A mode where positive airway pressure is maintained throughout the respiratory cycle.

  • Positive End-Expiratory Pressure (PEEP):

    • Positive pressure applied at end-expiration (5-10 cm H2O), which helps keep alveoli open during breathing cycles.

8. Nursing Responsibilities for Ventilator Settings

  • The nurse must verify ventilator settings every hour, including:

    • Rate

    • Tidal Volume (VT)

    • Oxygen concentration (FiO2)

    • Mode (Assist Control, SIMV, CPAP)