Nephrology POCUS
Point-of-Care Ultrasound essentials for the nephrologist.
External Resource
For comprehensive tutorials, image libraries, and deep dives, visitNephroPOCUS.com
Lung Ultrasound (LUS)
Assessment of extravascular lung water (Volume Status).
Key Finding: B-Lines
Vertical, hyperechoic artifacts arising from the pleural line and extending to the bottom of the screen. Move with lung sliding.
- Normal (A-profile): Horizontal A-lines (reverberation of pleural line). Dry lungs.
- Wet (B-profile): ≥ 3 B-lines in a rib space. Indicates interstitial syndrome (Pulmonary Edema in right context).
- Zones: Scan 4-8 zones per side (Blue points).
IVC Assessment
Estimation of Right Atrial Pressure (RAP).
Technique
Subxiphoid view, longitudinal. Measure 1-2 cm from RA junction during quiet respiration.
Small, Collapsing
< 2.1 cm, > 50% collapse
RAP ~ 3 mmHg
< 2.1 cm, > 50% collapse
RAP ~ 3 mmHg
Large, Fixed
> 2.1 cm, < 50% collapse
RAP ~ 15 mmHg
> 2.1 cm, < 50% collapse
RAP ~ 15 mmHg
Pitfalls: Ventilated patients (IVC dilates with inspiration), Intra-abdominal hypertension, TR.
Renal Ultrasound
Rule out obstruction and assess chronicity.
Hydronephrosis
Anechoic (black) separation of the central sinus complex. "Bear claw" appearance.
- Mild: Slight separation, calyces blunted.
- Moderate: Dilated pelvis and calyces.
- Severe: Cortical thinning, ballooning.
- Chronicity: Small size (< 9cm), increased echogenicity (brighter than liver/spleen), cortical thinning.
Bladder Volume
Assessment for retention.
Formula
Volume (mL) = 0.7 x Width x Height x Depth
Measure in transverse (Width) and longitudinal (Height, Depth) planes. Useful for confirming Foley placement or ruling out retention in AKI.
Sign In Required
Please sign in or register to access this clinical tool