Ultrasound: lungs

Pulmonary edema

• A lines and B lines
  • A lines:
    • Appear as horizontal lines
    • Indicate dry interlobular septa.
    • Predominance of A lines has 90% sensitivity, 67% specificity for pulmonary artery wedge pressure <= 13mm Hg
    • A line predominance suggests that intravenous fluids may be safely given without concern for pulmonary edema
  • B lines ("comets"):
    • White lines from the pleura to the bottom of the screen
    • Highly sensitive for pulmonary edema, but can be present at low wedge pressures