Download Disorders of the Pleura and Asthma and more Lecture notes Medicine in PDF only on Docsity!
MODULE 4 | DISORDERS OF THE PLEURA Pleurisy or Pleuritis ▪ Inflammation of both layers of the pleura (visceral and parietal) ▪ Usually related to infectious processes (pneumonia or upper respiratory infection). PLEURAL PAIN ▪ Results when the inflamed pleura rubs together Abrupt in onset and usually unilateral and tends to be localized. ▪ Made worse by movement (deep breathing, coughing) → breathing is painful → ↓ tidal volume. ▪ May increase pressure inside the pleural cavity. NSAIDs are given but do not entirely relieve pain. PLEURAL EFFUSION Refers to the accumulation of fluid in the pleural cavity usually secondary to other disease.
NORMAL PLEURAL FLUID → (5-15ML)
▪ Complication of heart failure, TB, pulmonary infections, Pneumonia, nephrotic syndrome, and Bronchogenic Carcinoma ▪ May be relatively clear fluid, or it can be bloody or purulent. TRANSUDATIVE = HYDROTHORAX ▪ Filtrate of plasma that moves across an intact capillary wall (extravasation) - > serous. ▪ Congestive heart failure, renal failure, liver failure - hypoalbuminemia, malignancy. 1 Increased capillary pressure 2 Increased capillary permeability 3 Decreased colloidal osmotic pressure 4 Increased^ negative^ intrapleural pressure (atelectasis) EXUDATIVE = INFLAMMATORY ▪ Pulmonary infections, malignancies, rheumatoid arthritis, lupus erythematosus. EMPYEMA = PUSS IN THE P. CAVITY ▪ Direct infection of the pleural space from an adjacent bacterial infection (bacterial pneumonia, rupture of lung abscess, infections associated with trauma) HEMOTHORAX ▪ presence of blood in the thoracic cavity ▪ Chest injury, complication of chest surgery, malignancies, rupture of great vessel (aortic aneurysm)
MODULE 4 | DISORDERS OF THE PLEURA ▪ A minimal hemothorax ( 300 – 500 ml ) usually clears in 10 – 14 days without complication. ▪ Moderate (500 – 1000 ml) and large (> 1000 ml). ▪ Hemothorax must be drained Complication : FIBROTHORAX – fusion of the pleural surfaces by fibrin, hyalin, and connective tissue. MANIFESTATIONS ▪ Blood loss ▪ Fever and other signs of ▪ inflammation ▪ Decrease lung expansion. ▪ Mediastinal shift toward the contralateral side ▪ Tracheal deviation away from the affected side ▪ Dullness/flatness to percussion, diminished breath sound ▪ Hypoxemia (dec. level of O2 in blood) ▪ Shortness of breath to acute respiratory distress DIAGNOSIS ▪ Chest radiographs ▪ Ultrasound ▪ Thoracentesis- Pleural fluid is analyzed by bacterial culture, gram stain, red and white blood cell count, chemistry, cytologic analysis for malignant cells. TREATMENT ▪ Directed at the underlying cause. ▪ Thoracentesis – to remove fluid and allow for reexpansion of the lung. ▪ Injection of sclerosing agent into the pleural cavity which causes obliteration of the pleural space (malignant conditions). Pneumothorax
- Presence of air in the pleural cavity
- Causes partial or complete collapse of the affected lung. Normally the pressure in the pleural space is negative or sub atmospheric - this negative pressure is required to maintain lung inflation. CAUSES SPONTANEOUS PNEUMOTHORAX Types of spontaneous pneumothorax:
- PRIMARY – occurs in healthy people.
- SECONDARY – occur in persons with lung disease – conditions that cause trapping of gases and destruction of lung tissue.
- CATAMENIAL PNEUMOTHORAX – occurs in relation to menstrual cycle – women with history of endometriosis; usually affects the right lung. TRAUMATIC PNEUMOTHORAX
- Caused by penetrating or non- penetrating injuries – fracture, dislocated ribs that penetrate the pleura, fracture of the trachea, medical procedures (insertion of needles into the chest, intubation, positive pressure ventilation, cardiopulmonary resuscitation).
MODULE 4 | DISORDERS OF THE PLEURA Atelectasis ▪ “Imperfect expansion” ▪ Incomplete expansion of a lung or portion of a lung CAUSES 1 Airway obstruction 2 Lung compression 3 Loss of pulmonary surfactant TYPES Primary atelectasis at birth Secondary atelectasis acquired MANIFESTATIONS ▪ Signs of hypoxemia ▪ Dyspnea ▪ Diminished chest expansion ▪ Absence of breath sounds ▪ Intercostal retractions ▪ Signs of infection may develop. ▪ Mediastinum and trachea shift to the affected side. In compression atelectasis, the mediastinum shifts away from the affected side. DIAGNOSIS
- CHEST RADIOGRAPHS - may reveal patchy infiltrates or consolidated area.
TREATMENT
GOAL : improve ventilation and remove secretion ▪ Treat underlying cause ▪ Ambulation and body positions that favor increased lung expansion. ▪ O2 supplement ▪ Bronchoscopy – for diagnosis and therapeutic purposes PREVENTION ▪ Change patient position frequently to promote ventilation and prevent secretion from accumulating. ▪ Encourage early mobilization and ambulation. ▪ Encourage deep breathing and coughing. ▪ Perform postural drainage. ▪ Institute suctioning Asthma ▪ Chronic inflammatory disease of the airways that causes airway hyperresponsiveness, mucosal edema and mucus production. ▪ Reversible ▪ Occurs at any age.
MODULE 4 | DISORDERS OF THE PLEURA PREDISPOSING FACTORS ✓ Allergy - pollens, dust, animal dander, food ✓ Airway irritants - air pollutants, cold, heat, weather changes, strong odors ✓ Respiratory tract infections ✓ Exercise, stress ✓ Hormonal changes ✓ Medications PATHOPHYSIOLOGY
- In response to exposure → Mast cells, macrophages, T lymphocytes, neutrophils, are activated → mast cells release chemical mediators: histamine, bradykinin, prostanoids, leukotrienes and others → inflammatory response: increased blood flow, vasoconstriction, fluid leak from the blood vessels (edema and ↑mucus secretion), bronchoconstriction.
- As asthma becomes persistent, inflammation progresses→ more edema, more mucus secretion → formation of mucus plugs → airway limitation.
- Chronic inflammation → airway remodeling (structural changes) → further airway narrowing. S/SX 3 MOST COMMON: 1 Cough 2 Dyspnea ✓ expiration requires effort and prolonged ✓ Use of accessory muscles 3 Wheezes – during expiration
- Chest tightness
- Unable to complete sentence between breaths.
- Diaphoresis
- Tachycardia
- Hypoxemia
- Central cyanosis ASSESSMENT HISTORY ✓ Chief complaint : shortness of breath, chest tightness, coughing, wheezing, and increased mucus production.
MODULE 4 | DISORDERS OF THE PLEURA METHYLXANTHINES Theophylline, Aminophylline ANTI-INFLAMMATORY AGENTS Corticosteroid MAST CELL STABILIZER → Binds to IgE receptor sites and prevents mast cells from opening MONOCLONAL ANTIBODIES → binds to IgE receptor sites on mast cells and basophils → prevents allergen from triggering the release of chemical mediators. LEUKOTRIENE ANTOGONISTS Zileuton (Zyflo ) prevents leukotrine synthesis Zafirlukast and Motelukast block the leukotriene receptor. ▪ Exercise/activity (aerobics) is recommended part of asthma therapy. ▪ Premedicate before doing an activity. ▪ Adjusting the environment ▪ O2 therapy STATUS ASTHMATICUS ➢A severe life-threatening acute episode of asthma that does not respond to common therapy ➢Uncontrolled, the patient may develop pneumothorax and cardiac or respiratory arrest ▪ Prepare for emergency intubation.
