Respiratory System Study Notes

RESPIRATORY ARTERIAL BLOOD GASES

• Understanding blood gas levels is essential in diagnosing and managing various respiratory and metabolic disorders.

METABOLIC ACIDOSIS vs. METABOLIC ALKALOSIS

METABOLIC ACIDOSIS

• Definition: Too much acid buildup in the body, leading to an increase in hydrogen ions.

  • Indicators:

  • Bicarbonate (HCO₃) level goes down.

  • pH goes down <7.35.

• Physiology:

  • Lungs compensate by blowing off CO₂ through faster breathing.

Causes of Metabolic Acidosis

1. Increased Acid Production:

   • Anything that causes acid production leads to increased hydrogen ions.

   • Examples:

     • Diabetic Ketoacidosis (DKA): Breakdown of fats, leading to excess ketones.

     • Sepsis: Buildup of lactic acid.

     • Alcoholism.

2. Decreased Acid Excretion:

   • Renal failure: Kidneys are unable to excrete waste, causing accumulation of acids.

3. Bicarbonate Loss:

   • Severe diarrhea: Bicarbonate loss contributes to acidosis.

Symptoms of Metabolic Acidosis

• Kussmaul's respirations: Deep, rapid breathing.

• Low blood pressure (BP).

• Confusion and hypoxia.

• EKG changes and weakness.

• Hyperkalemia leading to muscle twitching.

Treatment of Metabolic Acidosis

• Monitor electrolytes and neuro status.

• Initiate seizure precautions.

• Administer sodium bicarbonate.

  • Possibly require intubation if respiratory distress is severe.

• Dialysis may be necessary to remove toxins in cases of renal failure.

DIABETIC KETOACIDOSIS (DKA)

• Key Points:

  • Buildup of ketones (acids) in the body.

  • Administer regular insulin to stop fat breakdown and ketone production.

  • Closely monitor potassium levels due to shifts during acidosis correction.

Symptoms of DKA

• Respiratory compensation through slower breathing to retain CO₂.

Causes of Metabolic Alkalosis

1. Excess Loss of Acid:

   • Vomiting or excessive gastric suctioning.

2. Excess Bicarbonate:

   • Excess sodium bicarbonate administration.

   • Excessive consumption of alkaline substances (e.g., antacids).

   • Hyperaldosteronism leading to sodium-hydrogen exchange errors in the kidneys.

   • Use of loop diuretics, leading to hydrogen loss through urine.

Symptoms of Metabolic Alkalosis

• Lethargy and irritability.

• Tetany, which may show Chvostek's sign due to hypocalcemia.

Treatment of Metabolic Alkalosis

• Administer antiemetics (e.g., Ondansetron) for vomiting.

• Monitor electrolytes and initiate IV fluids to compensate for loss.

• Initiate seizure precautions.

• Consider stopping loop diuretics.

• Administer Acetazolamide (Carbonic Anhydrase Inhibitor) contributing to bicarbonate loss.

RESPIRATORY SYSTEM FUNCTIONS

Anatomy & Physiology

1. Upper Respiratory Tract:

   • Functions: Air preparation (warming, moistening, filtering).

   • Key components: Cilia and goblet cells secrete mucus to trap dust and particulate matter.

2. Lower Respiratory Tract:

   • Location of asthma pathology and gas exchange occurs in alveoli through pulmonary capillaries.

Specific Triggers & Host Factors of Respiratory Issues

Contributing Factors:

• Genetics, obesity, male gender pre-puberty increase risk for respiratory issues.

RESPIRATORY ACID-BASE BALANCE

RESPIRATORY ACIDOSIS

• Retention of CO₂, making the body more acidic.

• Indicators:

  • Increased CO₂ levels >45 mmHg.

  • pH goes down <7.35.

Causes of Respiratory Acidosis

1. Respiratory Depression due to:

   • Drug overdose (opioids, sedatives).

   • Increased intracranial pressure (ICP).

   • Neuromuscular diseases.

   • Sleep apnea.

2. Impaired Gas Exchange:

   • Conditions such as COPD, Pneumonia, chest wall trauma, and pulmonary edema.

Symptoms of Respiratory Acidosis

• Altered level of consciousness (confusion, drowsiness).

• Decreases in respiratory rate (RR < 12).

• Hypoxia and dysrhythmias (from hyperkalemia).

Treatment for Respiratory Acidosis

• Administer oxygen and suction secretions as necessary.

• Encourage deep breathing exercises.

• Administer antibiotics if pneumonia is present.

• Monitor potassium levels and hold respiratory depressants.

• Sodium bicarbonate only in severe cases.

RESPIRATORY ALKALOSIS

• Caused by excess loss of CO₂ through hyperventilation.

• Indicators:

  • Decreased CO₂ levels <35 mmHg.

  • Increased pH >7.45.

Causes of Respiratory Alkalosis

1. Hyperventilation causes:

   • Anxiety, pain, fever, asthma.

   • Pulmonary embolism and aspirin toxicity.

Symptoms of Respiratory Alkalosis

• Rapid respiratory and heart rates.

• Confusion and lethargy, leading to tetany.

• EKG changes may indicate hypokalemia.

Treatment for Respiratory Alkalosis

• Teach breathing techniques (e.g., rebreathing into a paper bag).

• Provide emotional support and supplemental oxygen.

• Administer anti-anxiety medications and analgesics as needed.

• Need to decrease tidal volume in mechanically ventilated patients.

ASTHMA

Definition

• Chronic lung disease characterized by inflammation and narrowing of airways, with excess mucus production.

Anatomy Involved

• Bronchi & Bronchioles:

  • Main air pathways leading to alveoli where gas exchange occurs.

Risk Factors for Asthma

• Genetic predisposition, obesity, smoking (including vaping), exposure to allergens.

Triggers for Asthma Exacerbation

1. Environmental:

   • Smoke, pollen, chemicals, stress, exercise, and respiratory infections.

2. Medications:

   • NSAIDs, Aspirin, and beta-blockers can induce bronchospasm.

Treatment of Asthma

• Immediate Relief Medications (Rescue Drugs):

  • Albuterol (SABA), Ipratropium (anti-cholinergic).

• Long-term Control Medications:

  • Inhaled corticosteroids (-SONES), leukotriene modifiers (-LUKAST).

  • Long-acting beta agonists (-TEROL).

• Educate patients on rinsing mouth after steroid use to avoid thrush, the importance of medication compliance, and using peak flow meter readings.

STATUS ASTHMATICUS

• Life-threatening condition due to severe airway obstruction unresponsive to traditional treatment:

Symptoms

• Severely laborious breathing, inability to speak, decreased level of consciousness, cyanosis.

Treatment

• Oxygen administration, intravenous fluids, bronchodilators, corticosteroids, and epinephrine.

• Prompt action required to prevent cardiac or respiratory arrest.

Monitoring and Education

• Monitor vital signs, lung sounds, and patient ability to breathe.

• Educate avoiding triggers and carrying rescue medications.

ACUTE RESPIRATORY DISTRESS SYNDROME (ARDS)

Definition

• Life-threatening lung condition causing severe alveolar damage due to inflammation and pulmonary edema.

Causes

1. Indirect:

   • Sepsis, pancreatitis, drug overdoses.

2. Direct:

   • Pneumonia, chest trauma, near-drowning, inhalation injury.

Presentation

• Exudative Phase:

  • Occurs 4-7 days post-injury with pulmonary edema and decreased surfactant.

Diagnosis

• Chest X-ray revealing "white-out" infiltrates, ABGs showing respiratory acidosis and hypoxemia not responsive to oxygen.

Treatment and Nursing Care

• Antibiotics for infection control, corticosteroids for inflammation, and diuretics for pulmonary edema management.

• High-flow oxygen or BiPAP may be necessary along with likely mechanical ventilation with paralyzing agents for complete control.

ARDS Stages

1. Proliferative Stage:

   • 7-21 days post-injury for lung repair; patients who do not recover may experience lung tissue density.

2. Fibrotic Stage:

   • Over 3 weeks post-injury with extensive scarring and end-stage lung disease, requiring intensive supportive care.

Nursing Interventions for ARDS

• Continuous monitoring of vital signs, ABGs, providing oxygen support, and managing fluid intake and output according to strict protocols.

CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)

Definition

• Group of chronic inflammatory lung diseases causing obstructed airflow in the lungs, primarily due to smoking.

Types of COPD

1. Chronic Bronchitis:

   • Inflammation of bronchial tubes with excess mucus production;

   • Symptoms include productive cough for 3 months in 2 consecutive years leading to right-sided heart failure.

2. Emphysema:

   • Damage to the alveoli’s inner structure leading to loss of elasticity and air trapping; characterized by "pink puffer" and minimal cough.

Symptoms of COPD

• Shortness of breath (dyspnea), cyanosis, chronic cough, crackles, and recurrent respiratory infections.

Diagnostic Measures

• Chest x-ray and arterial blood gas tests, along with spirometry to assess lung function (FEV1/FVC ratio).

Treatment

• Focus on symptom management with bronchodilators and corticosteroids.

• Essential to engage in pulmonary rehabilitation (exercise, breathing techniques, nutritional counseling).

Nursing Considerations

• Monitor oxygen saturation, ABGs, and lung sounds. Administer oxygen with caution to avoid hypercapnia. Educate on smoking cessation and avoidance of irritating factors that exacerbate COPD.

PNEUMOTHORAX vs. HEMOTHORAX

Definition

• Conditions involving air or blood buildup in the pleural space surrounding lungs.

Types of Pneumothorax

1. Open:

   • Due to external injury (e.g. gunshot, stabbing).

   • Treatment involves placing a sterile occlusive dressing.

2. Closed:

   • Caused by rib fractures or spontaneous rupture.

Symptoms of Pneumothorax

• Absent lung sounds, hyperresonance, unequal chest expansion, dyspnea.

Treatment for Pneumothorax

• Needle decompression if tension, followed by chest tube placement to remove air or fluid, and possibly thoracotomy in severe cases.

Symptoms of Hemothorax

• Blood sputum, absent lung sounds, dullness on percussion, hypotension. Treatment involves draining the blood with similar methods to pneumothorax intervention.

Nursing Interventions

• Monitor vital signs, chest tube insertion site, and complications such as air leaks. Encourage deep breathing exercises and ambulation with medical orders.