Restrictive Lung Disorders, ARDS, PH

What is the fundamental problem in restrictive lung disease?

The lungs cannot fully expand, causing decreased lung volumes such as decreased TLC and decreased FVC

What is the key spirometry finding that distinguishes restrictive from obstructive lung disease?

Restrictive disease has a normal or increased FEV1/FVC ratio while obstructive disease has a decreased FEV1/FVC ratio

What is the difference between intrinsic and extrinsic restrictive lung disease?

Intrinsic disease affects the lung tissue itself while extrinsic disease involves problems outside the lung such as the pleura, chest wall, muscles, or obesity

What are examples of intrinsic restrictive lung disease?

Idiopathic pulmonary fibrosis, pneumoconiosis, sarcoidosis, and hypersensitivity pneumonitis

What are examples of extrinsic restrictive lung disease?

Pleural disorders, chest wall disorders, neuromuscular weakness, and severe obesity

What is idiopathic pulmonary fibrosis?

Progressive, irreversible lung fibrosis of unknown cause

What is the pathogenesis of IPF?

Alveolar injury leads to abnormal healing and fibrosis, causing stiff lungs and impaired gas exchange

What are the classic symptoms of IPF?

Shortness of breath, chronic cough, fatigue, and weight loss

What medications are used to treat IPF?

Pirfenidone and nintedanib

What is the prognosis of IPF?

Median survival of two to three years

What other treatments besides medication are used for IPF?

Oxygen, pulmonary rehabilitation, and lung transplant in severe cases

What is the mechanism of action of nintedanib?

Blocks pathways involved in lung scarring to slow the decline in lung function

What are the adverse effects of nintedanib?

Diarrhea, nausea, and increased liver enzymes

What is the key adverse effect that distinguishes pirfenidone and requires patient teaching?

Photosensitivity, so sun protection should be taught

What is the mechanism of action of nerandomilast?

Inhibits PDE4 to slow the decline in lung function

What are the adverse effects of nerandomilast?

Diarrhea, decreased appetite, weight loss, and mood changes

What is the most important clinical pearl about all antifibrotic agents?

They slow the progression of fibrosis but do not cure it or reverse existing scarring

What is pneumoconiosis?

Lung disease caused by inhaling workplace dust that leads to nodules or scarring

What are the three main types of pneumoconiosis and their causes?

Asbestosis from asbestos, silicosis from silica, and coal workers pneumoconiosis from coal dust

Why is it important to ask about current and past jobs in a patient with suspected pneumoconiosis?

Because the disease is caused by workplace dust exposure and established scarring may be irreversible, so stopping exposure is the priority treatment

What is the pathogenesis of sarcoidosis?

Immune mediated Type IV, T cell mediated inflammation that forms noncaseating granulomas

What organs are most commonly affected by sarcoidosis?

The lungs and chest lymph nodes, and sometimes the skin and eyes

What diagnostic finding confirms sarcoidosis on biopsy?

Noncaseating granulomas

How is sarcoidosis treated?

Observation if mild, then corticosteroids, then other immunosuppressants if needed

What is the prognosis of sarcoidosis?

It may resolve on its own, but some cases become chronic, and permanent fibrosis can form if inflammation persists

Why is sarcoidosis linked to the Type IV hypersensitivity mnemonic of delayed reaction?

Because it is a T cell mediated, delayed immune process similar to contact dermatitis and the TB skin test

What is hypersensitivity pneumonitis?

An immune reaction to repeatedly inhaled substances that causes lung inflammation and can progress to fibrosis if exposure continues

What are common triggers of hypersensitivity pneumonitis?

Bird feathers or droppings, mold, and hay or grain dust

What symptoms suggest hypersensitivity pneumonitis rather than pleuritis?

Dry cough, shortness of breath, fatigue, and fever or chills after exposure, without pain on deep breathing

What is the priority treatment for hypersensitivity pneumonitis?

Find and avoid the causative trigger, with corticosteroids and oxygen as needed

What is a pneumothorax?

Air in the pleural space causing partial or complete lung collapse

What is the difference between a spontaneous and a traumatic pneumothorax?

Spontaneous occurs without injury while traumatic results from injury such as a gunshot, surgery, or accident

What happens in a tension pneumothorax?

Air enters the pleural space but cannot escape, so rising pressure compresses the lung and major vessels, decreasing venous return and cardiac output

What are the symptoms of a pneumothorax?

Sudden sharp chest pain, shortness of breath, decreased breath sounds on the affected side, and increased respiratory rate and heart rate

What is the priority treatment when a patient has a tension pneumothorax with hypotension?

Immediate needle decompression without waiting for imaging

How is a small, stable pneumothorax managed compared to a larger one?

A small stable pneumothorax may just be observed, while a larger one requires needle aspiration or a chest tube

Why does a tension pneumothorax cause shock?

Rising pleural pressure decreases venous return to the heart, which decreases cardiac output

What is a pleural effusion?

Fluid in the pleural space

What causes a transudate pleural effusion and what are examples?

A pressure imbalance, such as from heart failure or cirrhosis

What causes an exudate pleural effusion and what are examples?

Leaky capillaries, such as from pneumonia, cancer, or pulmonary embolism

What are the classic assessment findings of a pleural effusion?

Dullness to percussion and decreased breath sounds on the affected side

How is a pleural effusion treated?

Treat the underlying cause and perform thoracentesis, chest tube placement, or pleurodesis when indicated

What is pleuritis?

Inflammation of the pleura causing the inflamed layers to rub together and produce pain

What is the classic sign and symptom of pleuritis?

A pleural friction rub with sharp chest pain that worsens with breathing or coughing

How does pleuritis differ from hypersensitivity pneumonitis in presentation?

Pleuritis causes sharp pain with deep breathing, while hypersensitivity pneumonitis causes dry cough and fever or chills after exposure without pleuritic pain

What is the underlying problem in chest wall restrictive disorders?

The chest wall cannot fully expand, decreasing lung volumes even though the lung tissue itself is normal

What is kyphoscoliosis and how does it cause restrictive disease?

A combined curvature of the spine and rib cage that restricts chest movement and expansion

What spirometry pattern is seen in chest wall restrictive disorders?

Decreased TLC and FVC with a normal or increased FEV1/FVC ratio

What causes restrictive lung disease in neuromuscular disorders such as myasthenia gravis or ALS?

Weak respiratory muscles cause inadequate lung expansion and decreased vital capacity

Why are patients with neuromuscular weakness at increased risk for infection?

A weak cough leads to retained secretions

Why must worsening weakness in a neuromuscular disorder be treated as an emergency?

It can rapidly progress to hypoventilation and respiratory failure

How does severe obesity cause restrictive lung disease?

Excess thoracic and abdominal adiposity limits chest wall and diaphragmatic movement, decreasing lung expansion and lung volumes

What is the primary treatment for obesity related restrictive lung disease?

Weight reduction and management of the underlying condition

What is ARDS?

Acute inflammatory lung injury that causes severe hypoxemic respiratory failure

What are common causes of ARDS?

Sepsis, severe shock, pneumonia, aspiration, and major trauma

What is the pathophysiology of ARDS?

Inflammation damages the alveolar capillary membrane, causing protein rich fluid to leak into the alveoli, surfactant loss, alveolar collapse, and stiff lungs

Why is ARDS described as noncardiogenic pulmonary edema?

The fluid results from capillary leak due to inflammation rather than from heart failure

What is the hallmark diagnostic finding of ARDS?

Hypoxemia that is difficult to correct with oxygen, along with bilateral lung opacities not explained by heart failure

How is a ventilated ARDS patient managed?

Small tidal volumes, limited pressure, positive end expiratory pressure, prone positioning, and conservative fluid management

What does ARDS have in common with burns and exudative pleural effusions?

All involve capillary leak causing fluid to move out of the vasculature into tissue or the pleural space

What is pulmonary hypertension?

Increased pressure in the pulmonary circulation that makes the right ventricle work harder

What are common causes of pulmonary hypertension?

Left heart disease, lung disease or hypoxemia such as COPD or fibrosis, chronic blood clots, and pulmonary arterial hypertension

What test is used to confirm pulmonary hypertension after echocardiography raises suspicion?

Right heart catheterization

How does pulmonary hypertension relate to cor pulmonale from COPD?

Chronic lung disease raises pulmonary pressures, which causes right ventricular hypertrophy and right sided heart failure, the same process as cor pulmonale

What is the mechanism of action of sildenafil in pulmonary arterial hypertension and what must be avoided?

It increases nitric oxide and cGMP signaling to cause vasodilation, and nitrates must be avoided because they can cause severe hypotension

What is the mechanism of action of bosentan and what must be monitored?

It blocks endothelin to decrease vasoconstriction and remodeling, and liver function tests must be monitored because it is contraindicated in pregnancy

What is the mechanism of action of epoprostenol and what is the critical safety teaching?

It increases vasodilation and decreases platelet aggregation, and it must never be stopped abruptly because rebound pulmonary hypertension can be fatal

How is epoprostenol administered?

As a continuous infusion through a pump

What memory hook connects sildenafil, bosentan, and epoprostenol to their key safety points?

Sildenafil means stay away from nitrates, bosentan means no pregnancy and monitor the liver, and epoprostenol means never stop the pump

A patient with sudden sharp chest pain, absent breath sounds on one side, and dropping blood pressure after a car accident. What is the priority action?

Prepare for immediate needle decompression for a suspected tension pneumothorax

A patient with dullness to percussion and decreased breath sounds on one side has a history of heart failure. What type of pleural effusion is most likely and why?

A transudate, because heart failure increases pressure that pushes fluid into the pleural space

A patient reports sharp chest pain that worsens with a deep breath, and the nurse hears a friction rub. What condition does this suggest?

Pleuritis

A patient with a bird collection develops a dry cough, fever, and chills after cleaning the cage. What condition should the nurse suspect and what is the priority action?

Hypersensitivity pneumonitis, and the priority is identifying and avoiding the trigger

A patient with ARDS remains hypoxemic despite high flow oxygen and has bilateral infiltrates on chest x ray with a normal heart. What does this confirm?

The hallmark of ARDS, hypoxemia that does not improve with oxygen and is not caused by heart failure

Why is it important not to confuse hypersensitivity pneumonitis with pleuritis on an exam question?

Hypersensitivity pneumonitis causes dry cough, shortness of breath, and fever or chills after exposure, while pleuritis causes sharp pain that worsens with breathing, and mixing them up leads to the wrong diagnosis