Moist crackling rales

Specialty: Respiratory.

• wet crackles
• wet rallies
• alveolar bubble rales

Why it occurs

• Decompensated congestive heart failure with acute pulmonary edema (transudation of fluid into the alveolar space; sounds are generated by the opening of alveoli collapsed by fluid at the end of inspiration, typically auscultated in both lung bases symmetrically)
• Bacterial pneumonia in the resolution or exudative phase (presence of purulent inflammatory secretions inside the alveoli)
• Infected bronchiectasis with accumulation of distal purulent secretions
• Diffuse alveolar hemorrhage of any etiology (presence of intraalveolar free blood)
• Non-cardiogenic pulmonary edema due to acute respiratory distress syndrome (ARDS) or inhalation of toxic gases.

Initial workup

Chest x-ray (search for diffuse alveolar infiltrates, Kerley B lines, cardiomegaly or "butterfly wings" pattern); Thoracic ultrasound (demonstration of multiple bilateral diffuse B lines suggesting wet alveolar-interstitial syndrome); analytical arterial blood gas; Electrocardiogram; Blood analysis with determination of type B natriuretic peptide (BNP or NT-proBNP) and troponins.

Standard management

• Furosemide — loop diuretic, administered at doses of 40-80 mg directly intravenously if there is fluid overload of cardiac or renal origin
• Nitroglycerin — titrated intravenous infusion or transdermal patches in case of acute hypertensive cardiogenic lung edema
• Specific antibiotic treatment if associated with underlying pneumonia.