critical care ultrasound

Critical Care UltrasoundEdward M. Omron MD, MPH, FCCP

Critical Care ServiceAlta Bates Summit

Nomenclature for Transducer Locations

Normal four chamber subxiphoid view

Parasternal Short Axis and Subcostal View in Severe Right Ventricular Failure

Subxiphoid View:

Pulmonary Embolism with dilatedRight ventricle

After TPA administraton

Subcostal View: Massive Pulmonary Embolism

Pericardial Tamponade with Right Atrial Collapse

Subcostal View of Large Ventriculoseptal Defect and Left to Right Shunt

IVC Caliper Measurement as an Index of preload responsiveness

Only valid in sedated, mechanically ventilated patients

Mechanical ventilation: Inspiratory caliper increases secondary to positive thoracic pressure Expiratory caliper is constant

IVC caliper increases in right heart failure, hypervolemia, or could be normal

IVC caliper decreases in hypovolemia

Preload responsiveness:IVC Caliber change with respiration

IVC Collapse in HypovolemiaNotice Left Renal VeinEnd Expiratory Collapse

Measurement Technique• Valid only in mechanically ventilated Patients• The patient remains supine• IVC is sought in the longitudinal axis• Look for the left renal vein and measure distal to it• End expiratory measurement is needed• A caliper less than 10 mm was correlated with a

central venous pressure of less than 7 mm Hg– Sensitivity 84%, Specificity 95%, PPV 89%, NPV 92%

Caliper of IVC when Central Venous Pressure is altered