ACNP Pulmonary Pleural Cheat Sheet (DRAFT) by kissmekate

Pathop­hys­iology

Caused by increased drainage of fluid into the pleural space, increased production of fluid by cells in the pleural space, or decreased doing of fluid from the pleural space.

Symptoms

Often asympt­omatic. Dyspnea on exertion, peripheral edema, orthopnea, and PND.

Transu­dative Effusions

Pathop­hys­iology is due to either elevated capillary pressure in the visceral or parenteral pleura (as in CHF), or decreased plasma oncotic pressure (hypoa­lbu­min­emia).
• Causes include CHF, cirrhosis, PE, nephrotic syndrome, peritoneal dialysis, hypoal­bum­inemia, and atelec­tasis.
• pH is normally 7.4-7.55.

Causes

• Exudative pleural effusions left untreated can lead to empyema.
• Most cases occur as a compli­cation of bacterial pneumonia, but other foci of infection can spread to the pleural space (media­sti­nhtis, abscess).

Treatment

• Aggressive drainage of the pleura via thorac­entesis and antibiotic therapy.
• Very difficult to eradicate and recurrence is common.
• If severe and persis­tent, rib resection and open drainage may be necessary.

CXR

• Look for blunting of the costop­hrenic angle.
•250mL must accumulate before an effusion can be detected.
• Lateral decubitus films are more reliable for detecting small pleural effusions.
• Can also determine if the fluid is free or located.

Treatment

• For transu­dative, diuretics, sodium restri­ction, and therap­eutic thorac­entesis if massive and causing dyspnea.
• For exudative, treat underlying disease.
• For parapn­eumonic effusions, antibi­otics alone if uncomp­lic­ated.
• Compli­cated effusions or empyema require chest tube drainage, intrac­ellular injection of thromb­olytic agents (strep­tok­inase or urokinase) to accelerate drainage, and/or surgical lysis of adhesions.

Pleural Fluid Tests

• CBC, glucose, pH, amylase, TGs, microb­iology, and cytology.
• Elevated pleural amylase is associated with esophageal rupture, pancre­atitis, and malign­ancy.
• Milky, opalescent fluid is a chylot­horax.
• Frankly purulent fluid is empyema.
• Bloody effusion is associated with malign­ancy.
• Exudative effusions that are primarily lympho­cytic are associated with TB.
• pH<7.2 is associated with parapn­eumonic effusion or empyema.
• If glucos­e<60, rule out RA. Can also be low in other causes.

Traumatic

• Often iatrog­enic.
• Always obtain a CXR after transt­horacic needle aspira­tion, thorac­ent­esis, and central line placement.

Sponta­neous Secondary

• Occurs as a compli­cation of underlying lung disease, most commonly COPD.
• Smoking leads to chronic airway inflam­mation and formation of respir­atory bronch­iol­itis.
• The chronic destru­ction of alveoli leads to large alveolar blebs in the upper lobes, which can rupture and leak air into the pleural space.
• Other conditions include asthma, ILD, neoplasms, CF, and TB. More life-t­hre­atening because of lack of pulmonary reserve.

Signs

Decreased breath sounds, hyperr­eso­nance, decrea­sed­/absent tactile fremitus, medias­tinal shift toward the side of the pneumo­thorax.

Treatment

• If small and asympt­omatic, observ­ation as it should resolve sponta­neously in ~20days.
• Small chest tube with one-way valve may benefit some patients.
• If pneumo­thorax is larger or sympto­matic, supple­mental oxygen and chest tube insertion.
• If secondary, chest tube drainage is always indicated.

Pathop­hys­iology

• Accumu­lation of air within the pleural space such that tissues surrou­nding the opening into the pleural cavity act as valves, allowing air to enter but not to escape.
• The accumu­lation of air under positive pressure in the pleural space collapses the ipsila­teral lung and shifts the medias­tinum away form the side of the pneumo­thorax.

Signs

Hypote­nsion (cardiac filling is impaired due to compre­ssion of the great veins), distended neck veins, shift of trachea away from pneumo­thorax, decreased breath sounds, hyper resonance to percus­sion.