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.