Oxygenation and Tissue Perfusion Review

Oxygenation and Tissue Perfusion

Normal Structure and Function of Oxygenation

• Cardiovascular System
  • Blood Flow:
    • Superior Vena Cava to the right atrium.
    • Tricuspid valve to the right ventricle.
    • Pulmonary vasculature system to the lungs.
    • Lungs (for oxygenation).
    • Left atrium.
    • The mitral valve to the left ventricle.
    • Out to the body.
  • Heart
    • Shape: hollow, cone-shaped organ.
      • Four Chambers:
        • Atria (top chambers).
        • Ventricles (bottom chambers).
      • Three Layers:
        • Epicardium (outer layer).
        • Myocardium (middle layer, muscular).
        • Endocardium (inner layer).
  • Blood Circulation
    • Blood flow pathway: Arteries - Arterioles - Capillaries - Venules - Veins - (back to the heart).
    • Arterials vs. Venous: arteries carry blood out; veins bring blood back.
  • Cardiac Stimulation
    • Begins in the Sinoatrial (SA) node.
    • SA node: The primary pacemaker is firing 60-100 times per minute (normal pulse rate).
    • AV node: Backup pacemaker, firing 40-60 times per minute, may indicate a need for a pacemaker.
  • Cardiac Output
    • Calculated by multiplying the heart rate in beats per minute (beats/min or bpm) times stroke volume in liters per beat.
    • Cardiac Output = Heart Rate \times Stroke Volume
      • Preload: work on the heart before contraction.
      • Afterload: work on the heart after contraction.
• Respiratory System
  • Upper Respiratory Tract
    • Nose, nasal cavity, sinuses, and pharynx.
  • Lower Respiratory Tract
    • Larynx, trachea, lungs.
  • Inspiration: is inhaling.
  • Expiration: is exhaling.

Risk Factors for Cardiovascular Disease (CVD)

• Non-Modifiable
  • Heredity
  • Family history
  • Genetics
  • Age
  • Gender
• Modifiable
  • Elevated serum lipid level (high cholesterol)
  • Hypertension (HTN)
  • Cigarette Smoking
  • Diabetes
  • Obesity
  • Sedentary Lifestyle

Altered Structure and Function of Oxygenation

• Cardiovascular Alterations
  • Decreased blood flow
  • Interrupted electrical impulses
  • Electrolyte disturbances
  • Cardiac failure
• Respiratory Alterations
  • Chronic Obstructive Pulmonary Disease (COPD)
  • Asthma
  • Pneumonia
  • Atelectasis
  • Respiratory failure
  • COVID-19

Heart Failure

• Factors That Can Disrupt Heart Function
  • Inadequate blood flow leads to symptoms resembling fluid volume deficit (low blood pressure, high heart rate, thirst, poor skin turgor).
  • Interrupted electrical impulses can result from SA node dysfunction or glitching, leading to conditions like Atrial Fibrillation (AFib).
  • Electrolyte imbalances, especially with potassium, magnesium, sodium, and calcium, can also disrupt heart function.
  • Heart failure, where the heart starts to fail.
• Symptoms
  • Shortness of breath
    • With exertion or when lying supine (flat on the back).
  • Orthopnea: preference to sleep in a recliner or propped up on multiple pillows due to difficulty breathing when lying flat.
  • Weight gain
    • 2-3 lbs in 1 day or 5 lbs in a week.
  • Increased cough
    • With pink-tinged sputum indicating blood in the lungs.
  • New or increased swelling
    • Ankles, feet, or abdomen.

Hypoxemia and Hypoxia

• Hypoxemia
  • Low levels of oxygen in the blood.
• Hypoxia
  • Insufficient oxygen anywhere in the body.
  • Signs/Symptoms:
    • Increased pulse.
    • Shallow respirations.
    • Dyspnea (difficulty breathing).
    • Increased restlessness.
    • Cyanosis (bluish discoloration of the skin and mucous membranes).
    • Nasal flaring.
    • Retractions (drawing in of the chest wall during inspiration).

Assessment

• Health history
  • Alterations of the cardiopulmonary system.
• Vital signs
• Inspection, palpation, and auscultation of heart and lungs
• Cough assessment: ability to cough, sound of cough, and any sputum production.
• Peripheral vascular assessment: pulses in the legs, arms, capillary refill, skin appearance, and temperature of extremities.
• Laboratory and Diagnostic Tests
  • Pulmonary function tests: measure breathing volume and capacities.
  • Complete blood count (CBC)
    • White blood count (WBC): indicates infection
    • Hemoglobin (Hgb) and Hematocrit (Hct)
  • Basic metabolic panel (BMP), Electrolytes, Creatine, and BUN: assess how the heart is pumping and what the body is getting rid of.
  • Arterial blood gases (ABGs): blood oxygen levels, pH, arterial CO2, and bicarbonate levels.
  • Lipids are assessed as a blockage to the heart.
    • Total cholesterol
    • Low-density lipoprotein (LDL) cholesterol
    • High-density lipoprotein (HDL) cholesterol
    • Triglycerides
  • Cardiac enzymes: indicate cardiac muscle breakdown, and elevated levels suggest a heart attack (troponin).
  • Chest X-ray: assess lung condition, looking for air (black) vs. infection or fluid (white).
  • Electrocardiogram (ECG/EKG): assesses the heart's electrical activity and rhythm.
    • 12-lead
  • Cardiac Monitoring
    • Echocardiogram: assess blood flow through the heart using ultrasound and measure the percentage of blood leaving the left ventricle with each contraction.
    • Cardiac Catheterization: an invasive procedure to visualize and treat heart blockages in the heart’s arteries.

Electrocardiogram (ECG/EKG) Components

• P wave
• QRS complex
• T wave
• U wave
• PR interval
• QT interval
• ST segment
• PR segment
• J point

Nursing Diagnosis

• Examples:
  • Impaired Gas Exchange
    • Supporting Data: Shortness of breath at rest and with activity, COPD, 35-year history of smoking, smokes 1 ppd, R 28 and shallow, SpO2 of 90% on 2 L of oxygen via nasal cannula, breath sounds diminished middle and lower right lobes on auscultation, productive cough of thick green sputum.
  • Impaired Breathing
    • Supporting Data: Ineffective movement of air into and out of the lungs, difficulty breathing with activity and at rest, use of pursed-lip breathing.
  • Impaired Cardiac Output
    • Supporting Data: Decreased pumping ability of the heart decreases activity tolerance.

Implementation and Evaluation

• Promoting optimal cardiopulmonary function
  • Positioning: sitting the patient up
    • Orthopneic: sitting upright
    • Tripoding: leaning forward over a table
    • High Fowler’s
  • Coughing
  • Deep breathing
  • Incentive spirometer: slow, steady inspirations and to raise the inner chamber.
  • Oxygen therapy
    • Oxygen administration
    • Oxygen delivery systems
      • Low-flow systems (nasal cannula): 1-6 L per minute and humidify at 4 L.
      • Reservoir systems (simple face mask): 5-8 L per minute and a minimum of 5 L to prevent CO2 build-up.
      • Venturi mask: delivers a specific oxygen concentration; it’s good for patients who have COPD.
        • Uses color-coded adapters to adjust the % of oxygen delivered.
      • Partial Rebreather: delivers less oxygen and has flaps on the side.
      • High-flow systems (non-rebreather): deliver high concentration of oxygen (90-100%) in patients with respiratory distress. Also has flaps to prevent air coming in.
      • Bag-valve-mask (BVM): used for patients who are not breathing.
    • Artificial airways
      • Pharyngeal airways
        • Nasopharyngeal airway
        • Oropharyngeal airway
      • Tracheal airways
        • Endotracheal tube
        • Tracheostomy tube
    • Diet therapy
      • High-fiber and low-fat diet
    • Exercise programs
      • 30 minutes of aerobic exercise 5 times a week
    • Anticoagulant therapy
      • It is used to prevent blood clots in the atrium for cardiac arrhythmias like atrial fibrillation.
      • Used to prevent VTE (Venous Thromboembolism) like DVT (Deep Vein Thrombosis) and PE (Pulmonary Embolism).
      • Symptoms of PE: SOB (Shortness of Breath), chest pain.
    • Anti-embolism hose
      • Promote venous blood return and prevent edema
    • Sequential compression devices
      • Reduce risk for lower extremity venous stasis
    • Medications for pulmonary diseases
      • Oral bronchodilators
      • Inhalation therapy: delivers medicine directly to the lungs
      • Bronchodilators: enlarge the bronchioles in the lungs
      • Anticholinergic agents
      • Corticosteroids: help the lungs function properly
      • Vaccines: RSV, pneumonia, flu, and Covid 19
      • Antibiotics: treat infections for pneumonia before obtaining a sputum culture to identify a specific infection
      • Mucolytic therapy: helps break down and clear mucus
      • Leukotriene modifiers: address mucus production at its source
    • Medications for cardiovascular diseases
      • Hypertension:
        • Diuretics (thiazides)
        • Angiotensin-converting enzyme (ACE) inhibitors
        • Angiotensin II receptor antagonists
        • Beta-blockers
        • Calcium channel blockers
        • Alpha-1 antagonists
        • Alpha-2 agonists
        • Vasodilators
      • Heart failure or edema:
        • Diuretics: used for heart failure and to remove fluid from the body
      • Arrhythmias or heart failure:
        • Antiarrhythmics: medication to prevent arrhythmias (irregular heartbeat)
    • Patient education
      • Heart failure patient education
      • Smoking cessation
      • Immunizations
        • Pneumonia national hospital inpatient quality measures
        • Quality measures for caring for pneumonia patients
        • Pneumococcal vaccination
        • Blood cultures
        • Antibiotic therapy
    • Evaluation
      • Evaluation of goal statements and desired outcomes helps the nurse modify the plan of care according to goal attainment.
      • Not achieving the desired outcomes prompts the nurse to modify the care plan according to current assessment data.
      • Continuation or modification of the plan of care is based on the patient’s reevaluation and is designed to meet basic oxygen needs.