NCLEX: Respiratory disorders

Respiratory disorders: Common respiratory disorders

Focus topic: Respiratory disorders

Respiratory disorders: Pleural effusion

Focus topic: Respiratory disorders

Pleural effusion is an excess of fluid in the pleural space. Normally this space contains a small amount of extracellular fluid that lubricates the pleural surfaces. Increased production or inadequate removal of this fluid results in transudative or exudative pleural effusion. Empyema is the accumulation of pus and necrotic tissue in the pleural space.

What causes it
Transudative pleural effusion can stem from:
• heart failure
• hepatic disease with ascites
• peritoneal dialysis
• hypoalbuminemia
• disorders resulting in overexpanded intravascular volume. Exudative pleural effusion can stem from:
• TB
• subphrenic abscess
• esophageal rupture
• pancreatitis
• bacterial or fungal pneumonitis or empyema
• cancer
• pulmonary embolism with or without infarction
• collagen disorders (such as lupus erythematosus and rheumatoid arthritis)
• myxedema
• chest trauma.

Pathophysiology
In transudative pleural effusion, excessive hydrostatic pressure or decreased osmotic pressure allows excessive fluid to pass across intact capillaries, resulting in an ultra filtrate of plasma containing low concentrations of protein. In exudative pleural effusion, capillaries exhibit increased permeability, with or without changes in hydrostatic and colloid osmotic pressures, allowing protein-rich fluid to leak into the pleural space. Empyema is usually associated with infection in the pleural space.

Respiratory disorders

Respiratory disorders

What to look for
Assess your patient for the following signs and symptoms:
• dyspnea, dry cough
• pleural friction rub
• possible pleuritic pain that worsens with coughing or deep breathing
• dullness on percussion
• tachycardia, tachypnea
• decreased chest motion and breath sounds.

What tests tell you
• In transudative effusions, pleural fluid (obtained by thoracentesis) has a specific gravity that’s usually less than 1.015 and protein less than 3 g/dl.
• In exudative effusions, pleural fluid has a specific gravity that’s greater than 1.02, and the ratio of protein in pleural fluid to serum is equal to or greater than 0.5. Pleural fluid lactate dehydrogenase (LD) is equal to or greater than 200 IU, and the ratio of LD in pleural fluid to LD in serum is equal to or greater than 0.6.
• If a pleural effusion results from esophageal rupture or pancreatitis, amylase levels in aspirated fluid are usually higher than serum levels.
• In empyema, cell analysis shows leukocytosis.
• Aspirated fluid may also be tested for lupus erythematosus cells, antinuclear antibodies, and neoplastic cells. It may be analyzed for color and consistency; acid-fast bacillus, fungal, and bacterial cultures; and triglycerides (in chylothorax).
• Chest X-ray shows radiopaque fluid in dependent regions.
• Pleural biopsy may be particularly useful for confirming TB or cancer.

How it’s treated
Depending on the amount of fluid present, symptomatic effusion requires either thoracentesis to remove fluid or careful monitoring of the patient’s own fluid reabsorption. Hemothorax requires drainage to prevent fibrothorax formation. Associated hypoxia requires supplemental oxygen.

What to do
• Administer oxygen as ordered.
• Provide meticulous chest tube care and use sterile technique for changing dressings around the tube insertion site in empyema. Record the amount, color, and consistency of tube drainage.
• If the patient has open drainage through a rib resection or an intercostal tube, use hand hygiene and contact precautions. Because weeks of such drainage are usually necessary to obliterate the space, make visiting nurse referrals for patients who will be discharged with the tube in place.
• If pleural effusion was a complication of pneumonia or influenza, advise prompt medical attention for chest colds.
• Evaluate the patient. He should have minimal chest discomfort, be afebrile, and have a normal respiratory pattern.

Respiratory disorders

Respiratory disorders: Pneumonia

Focus topic: Respiratory disorders

Pneumonia is an acute infection of the lung parenchyma that commonly impairs gas exchange. The prognosis is usually good for people who have normal lungs and adequate host defenses before the onset of pneumonia; however, bacterial pneumonia is the fifth leading cause of death in debilitated patients. The disorder occurs in primary and secondary forms.

What causes it
Pneumonia is caused by an infecting pathogen (bacterial or viral) or by a chemical or other irritant (such as aspirated material). Certain predisposing factors increase the risk of pneumonia. For bacterial and viral pneumonia, these include:
• chronic illness and debilitation
• cancer (particularly lung cancer)
• abdominal and thoracic surgery
• atelectasis, aspiration
• colds or other viral respiratory infections
• chronic respiratory disease, such as COPD,
asthma, bronchiectasis, and cystic fibrosis
• smoking, alcoholism
• malnutrition
• sickle cell disease
• tracheostomy
• exposure to noxious gases
• immunosuppressive therapy
• immobility or decreased activity level.

Aspiration pneumonia is more likely to occur in elderly or debilitated patients, those receiving NG tube feedings, and those with an impaired gag reflex, poor oral hygiene, or a decreased LOC.

Pathophysiology
In general, the lower respiratory tract can be exposed to pathogens by inhalation, aspiration, vascular dissemination, or direct contact with contaminated equipment such as suction catheters. After pathogens are inside, they begin to colonize and infection develops.

Stasis report

Focus topic: Respiratory disorders

In bacterial pneumonia, which can occur in any part of the lungs, an infection initially triggers alveolar inflammation and edema. This produces an area of low ventilation with normal perfusion. Capillaries become engorged with blood, causing stasis. As the alveolar capillary membrane breaks down, alveoli fill with blood and exudate, resulting in atelectasis. In severe bacterial infections, the lungs look heavy and liver like — similar to ARDS.

Virus attack!

Focus topic: Respiratory disorders

In viral pneumonia, the virus first attacks bronchiolar epithelial cells. This causes interstitial inflammation and desquamation. The virus also invades bronchial mucous glands and goblet cells. It then spreads to the alveoli, which fill with blood and fluid.

Subtracting surfactant

Focus topic: Respiratory disorders

In aspiration pneumonia, inhalation of gastric juices or hydrocarbons triggers inflammatory changes and inactivates surfactant over a large area. Decreased surfactant leads to alveolar collapse. Acidic gastric juices may damage the airways and alveoli. Particles containing aspirated gastric juices may obstruct the airways and reduce airflow, leading to secondary bacterial pneumonia.

What to look for
The five cardinal signs and symptoms of early bacterial pneumonia are:
coughing
sputum production
pleuritic chest pain
shaking chills
fever.

Other signs vary widely, ranging from diffuse, fine crackles to signs of localized or extensive consolidation and pleural effusion.

What tests tell you
• Chest X-rays showing infiltrates and a sputum smear demonstrating acute inflammatory cells support the diagnosis.
• Positive blood cultures in patients with pulmonary infiltrates strongly suggest pneumonia produced by the organisms isolated from the blood cultures.
• Occasionally, a transtracheal aspirate of tracheobronchial secretions or bronchoscopy with brushings may be done to obtain material for smear and culture.

How it’s treated
Antimicrobial therapy varies with the infecting agent. Therapy should be reevaluated early in the course of treatment. Supportive measures include:
• humidified oxygen therapy for hypoxemia
• mechanical ventilation for respiratory failure
• a high-calorie diet and adequate fluid intake
• bed rest
• an analgesic to relieve pleuritic chest pain.

What to do
• Maintain a patent airway and adequate oxygenation. Measure ABG levels, especially in hypoxic patients. Administer supplemental oxygen as ordered. If the patient has underlying COPD, give oxygen cautiously.
• Administer antibiotics as ordered and pain medication as needed. Fever and dehydration may require I.V. fluids and electrolyte replacement.

Mangi, mangi!

Focus topic: Respiratory disorders

  • Maintain adequate nutrition to offset extra calories burned during infection. Ask the dietary department to provide a high-calorie, high-protein diet consisting of soft, easy-to-eat foods. Encourage the patient to eat and to drink fluids. Monitor fluid intake and output.
  • To control the spread of infection, dispose of secretions properly. Teach the patient respiratory hygiene/cough etiquette, and tell him to sneeze and cough into a disposable tissue; tape a waxed bag to the side of the bed for used tissues.
  • To prevent aspiration during NG tube feedings, elevate the patient’s head, check the position of the tube, and administer feedings slowly. Don’t give large volumes at one time because this could cause vomiting. If the patient has a tracheostomy or an ET tube, inflate the tube cuff. Keep his head elevated for at least 30 minutes after feeding.
  • Be aware that antimicrobial agents used to treat cytomegalovirus, PCP, and respiratory syncytial virus pneumonia may be hazardous to fetal development. Pregnant health care workers or those attempting conception should minimize exposure to these agents (such as acyclovir [Zovirax], ribavirin [Virazole], and pentamidine [Pentam 300]).
  • Evaluate the patient. His chest X-rays should be normal and his ABG levels should show PaO2 of 50 to 60 mm Hg.

Respiratory disorders

Respiratory disorders: Pneumothorax

Focus topic: Respiratory disorders

In pneumothorax, air or gas accumulates between the parietal and visceral pleurae, causing the lungs to collapse. The amount of air or gas trapped determines the degree of lung collapse. In some cases, venous return to the heart is impeded, causing a life-threatening condition called tension pneumothorax.

When spontaneity is a bad thing

Focus topic: Respiratory disorders

Pneumothorax is classified as either traumatic or spontaneous. Traumatic pneumothorax may be further classified as open (sucking chest wound) or closed (blunt or penetrating trauma). An open (penetrating) wound may in turn cause closed pneumothorax if communication between the atmosphere and the pleural space seals itself off. Spontaneous pneumothorax — also considered closed — can be further classified as primary (idiopathic) or secondary (related to a specific disease).

What causes it
Spontaneous pneumothorax can result from:
• ruptured congenital blebs
• ruptured emphysematous bullae
• tubercular or malignant lesions that erode into the pleural space
• interstitial lung disease such as eosinophilic granuloma. Traumatic pneumothorax can result from:
• insertion of a central venous access device
• thoracic surgery
• thoracentesis or closed access device
• penetrating chest injury
• transbronchial biopsy.

Respiratory disorders

Tension pneumothorax can develop from either spontaneous or traumatic pneumothorax.

Pathophysiology
The pathophysiology of pneumothorax varies according to classification.

A change in atmosphere

Focus topic: Respiratory disorders

Open pneumothorax results when atmospheric air (positive pressure) flows directly into the pleural cavity (negative pressure). As the air pressure in the pleural cavity becomes positive, the lung collapses on the affected side. Lung collapse leads to decreased total lung capacity. The patient then develops V imbalance, leading to hypoxia.

Leaking lung

Focus topic: Respiratory disorders

Closed pneumothorax occurs when air enters the pleural space from within the lung, causing increased pleural pressure and preventing lung expansion during inspiration. It may be called traumatic pneumothorax when blunt chest trauma causes lung tissue to rupture, resulting in air leakage.

The domino effect

Focus topic: Respiratory disorders

Spontaneous pneumothorax is a type of closed pneumothorax. The usual cause is rupture of a subpleural bleb (a small cystic space) at the surface of the lung. This rupture causes air leakage into the pleural spaces; then the lung collapses, causing decreased total lung capacity, vital capacity, and lung compliance — leading, in turn, to hypoxia.

What to look for
Spontaneous pneumothorax may not produce symptoms in mild cases, but profound respiratory distress occurs in moderate to severe cases. Weak and rapid pulse, pallor, jugular vein distention, and anxiety indicate tension pneumothorax. In most cases, look for these symptoms:
• sudden, sharp, pleuritic pain
• asymmetrical chest wall movement
• shortness of breath
• cyanosis
• decreased or absent breath sounds over the collapsed lung
• hyperresonance on the affected side
• crackling beneath the skin on palpation (subcutaneous emphysema).

What tests tell you
• Chest X-rays show air in the pleural space and may reveal mediastinal shift.
• If pneumothorax is significant, ABG findings include pH less than 7.35, PaO2 less than 80 mm Hg, and PaCO2 above 45 mm Hg.

How it’s treated
Treatment is conservative for spontaneous pneumothorax in cases where no signs of increased pleural pressure appear, lung collapse is less than 30%, and the patient shows no signs of dyspnea or other indications of physiologic compromise. Such treatment consists of:
• bed rest or activity as tolerated by the patient
• careful monitoring of blood pressure, pulse rate, and respirations
• oxygen administration
• in some cases, needle aspiration of air with a large-bore needle attached to a syringe.

Also, keep in mind these treatment pointers:
• When more than 30% of the lung has collapsed, reexpansion of the lung is performed by placing a thoracotomy tube in the second or third intercostal space at the midclavicular line. This procedure is done to allow air to rise to the top of the intrapleural space. The tube is connected to an underwater seal with suction at low pressures.
• Recurring spontaneous pneumothorax requires thoracotomy and pleurectomy. These procedures prevent recurrence by causing the lung to adhere to the parietal pleura.
• Traumatic or tension pneumothorax requires chest tube drainage.
• Traumatic pneumothorax may also require surgical repair.

What to do
• Watch for pallor, gasping respirations, and sudden chest pain.
• Carefully monitor vital signs at least every hour for indications of shock, increasing respiratory distress, or mediastinal shift. Listen for breath sounds over both lungs. Falling blood pressure with rising pulse and respiratory rates may indicate tension pneumothorax, which can be fatal if not promptly treated.
• Make the patient as comfortable as possible — a patient with pneumothorax is usually most comfortable sitting upright.
• Urge the patient to control coughing and gasping during thoracotomy.

Take a deep breath

Focus topic: Respiratory disorders

  • After the chest tube is in place, encourage the patient to cough and breathe deeply at least once per hour to promote lung expansion.
  • In the patient undergoing chest tube drainage, watch for continuing air leakage (bubbling) in the water-seal chamber. This indicates the lung defect has failed to close and may require surgery. Also observe for increasing subcutaneous emphysema by checking around the neck or at the tube insertion site for crackling beneath the skin. If the patient is on a ventilator, be alert for any difficulty in breathing in time with the ventilator as you monitor its gauges for pressure increases.
  • Change dressings around the chest tube insertion site as needed and as per your facility’s policy. Don’t reposition or dislodge the tube; if the tube does dislodge, immediately place a petroleum gauze dressing over the opening to prevent rapid lung collapse.
  • Observe the chest tube site for leakage, and note the amount and color of drainage. Walk the patient as ordered (usually on the first postoperative day) to promote deep inspiration and lung expansion.
  • Reassure the patient by explaining what occurs with pneumothorax, its causes, and all accompanying diagnostic tests and procedures.
  • Evaluate the patient. He should have normal chest X-rays, respiratory rate and depth, and vital signs.

Respiratory disorders

Respiratory disorders: Pulmonary embolism and infarction

Focus topic: Respiratory disorders

Pulmonary embolism is an obstruction of the pulmonary arterial bed by a dislodged thrombus or foreign substance. Pulmonary infarction, or lung tissue death from a pulmonary embolus, is sometimes mild and may not produce symptoms. However, when a massive embolism occurs involving more than 50% obstruction of pulmonary arterial circulation, it can be rapidly fatal.

What causes it
Pulmonary embolism usually results from dislodged thrombi that originate in the leg veins. Other less common sources of thrombi are the pelvic, renal, hepatic, and arm veins and the right side of the heart.

Pathophysiology
Trauma, clot dissolution, sudden muscle spasm, intravascular pressure changes, or a change in peripheral blood flow can cause the thrombus to loosen or fragmentize. Then the thrombus — now called an embolus — floats to the heart’s right side and enters the lung through the pulmonary artery. There, the embolus may dissolve, continue to fragmentize, or grow.

Death threat

Focus topic: Respiratory disorders

If the embolus occludes the pulmonary artery, alveoli collapse and atelectasis develops. If the embolus enlarges, it may clog most or all of the pulmonary vessels and cause death.

A rare find

Focus topic: Respiratory disorders

Rarely, the emboli contain air, fat, amniotic fluid, or tumor cells. They may also contain talc from drugs intended for oral administration that I.V. drug addicts have injected. Pulmonary embolism may lead to pulmonary infarction, especially in patients with chronic heart or pulmonary disease.

What to look for
Total occlusion of the main pulmonary artery is rapidly fatal; smaller or fragmented emboli produce symptoms that vary with the size, number, and location of the emboli. Dyspnea is usually the first symptom of pulmonary embolism and may be accompanied by anginal or sharp pleuritic chest pain that worsens with inspiration. Other clinical features include tachycardia, productive cough (sputum may be blood-tinged), and low-grade fever.
Less common signs include massive hemoptysis, splinting of the chest, and leg edema. A large embolus may produce right sided heart failure with cyanosis, syncope, and distended jugular veins. Signs of shock (such as weak, rapid pulse and hypotension) and hypoxia (such as restlessness) may also occur. Cardiac auscultation occasionally reveals a right ventricular third heart sound audible at the lower sternum and increased intensity of a pulmonary component of the second heart sound. Crackles and a pleural friction rub may be heard at the infarction site.

What tests tell you
• Chest X-rays show a characteristic wedge-shaped infiltrate that suggests pulmonary embolism. X-ray studies may also rule out other pulmonary diseases and reveal areas of atelectasis, an elevated diaphragm, pleural effusion, and a prominent pulmonary artery.
• Lung scan shows perfusion defects in areas beyond occluded vessels; a normal lung scan rules out pulmonary embolism.
• Spiral CT angiography can help visualize the embolus and lungs.

Risky business

Focus topic: Respiratory disorders

  • Pulmonary angiography is the most definitive test but poses some risk to the patient (such as allergic reaction to the dye, infection at the catheter site, and kidney failure related to difficulty excreting dye). Its use depends on the uncertainty of the diagnosis and the need to avoid unnecessary anticoagulant therapy (treatment of pulmonary embolism) in high-risk patients.
  • ECG is inconclusive but helps distinguish pulmonary embo lism from MI. In extensive embolism, the ECG may show right axis deviation; right bundle-branch block; tall, peaked P waves; depressed ST segments and T-wave inversions (indicating right heart strain); and supraventricular tachyarrhythmias.
  • ABG measurements showing decreased PaO2 and PaCO2 are characteristic but don’t always occur.
  • An elevated D-dimer level indicates the presence of a blood clot in the body and strongly suggests a pulmonary embolism.

How it’s treated
Treatment aims to maintain adequate cardiovascular and pulmo nary function as the obstruction resolves and to prevent recurrence. Because most emboli resolve within 10 days, treatment consists of oxygen therapy as needed and anticoagulation with heparin to inhibit new thrombus formation.

Massive means more

Focus topic: Respiratory disorders

Patients with massive pulmonary embolism and shock may require thrombolytic therapy with a tissue plasminogen activator such as (Alteplase) to enhance fibrinolysis of the pulmonary emboli and remaining thrombi. Hypo tension related to pulmonary emboli may be treated with vasopressors.

Seek the septic source

Focus topic: Respiratory disorders

Treatment for septic emboli requires antibiotic therapy as well as evaluation of the source of infection, particularly in cases of endocarditis. Anticoagulants aren’t used to treat septic emboli.

Surgery saved for last

Focus topic: Respiratory disorders

Surgery to interrupt the inferior vena cava is reserved for patients for whom anticoagulants are contraindicated (for example, because of age, recent surgery, or blood dyscrasia) or who have recurrent emboli during anticoagulant therapy. It should only be performed when pulmonary embolism is confirmed by angiography. Surgery may consist of vena caval ligation, plication, or insertion of an umbrella filter for blood returning to the heart and lungs. The patient may receive a combination of low-dose heparin or low-molecular-weight heparin (enoxaparin [Lovenox]) to prevent postoperative venous thromboembolism.

What to do
• Give oxygen by nasal cannula or mask.
• Check ABG levels if fresh emboli develop or dyspnea worsens.

• Be prepared to provide equipment for ET intubation and assisted ventilation if breathing is severely compromised. If necessary, prepare to transfer the patient to an ICU according to facility policy.
• Administer heparin as ordered through continuous drip.
• Monitor coagulation studies daily and after changes in heparin dosage. Maintain adequate hydration to avoid the risk of hypercoagulability.

Walking the walk

Focus topic: Respiratory disorders

  • After the patient is stable, encourage him to move about often and assist with isometric and ROM exercises. Check his temperature and the color of his feet to detect venostasis. Never vigorously massage the patient’s legs. Walk the patient as soon as possible after surgery to prevent venostasis.
  • Report frequent pleuritic chest pain so that analgesics can be prescribed.
  • Evaluate the patient. His vital signs should be within normal limits, and he should show no signs of bleeding after anticoagulant therapy.

Respiratory disorders

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