The rapid ultrasound in shock (RUSH) protocol is a structured point-of-care ultrasound (POCUS) examination performed at the time of presentation of a shocked patient. It is a more detailed and longer exam than the FAST scan, with the aim to differentiate between hypovolemic, cardiogenic, obstructive and distributive shock.
It is invariably performed by a clinician, who should be formally trained and can be considered as an 'extension' of the shock clinical assessment process, to aid rapid decision making.
Protocol
The protocol 1 includes assessment of the 'pump, tank and pipes':
- the pump: the heart
- pericardial effusion
- signs of tamponade
- left ventricular (LV) contractility
- signs of right ventricular (RV) strain
- the tank: the lungs
- inferior vena cava (IVC) volume and collapse with inspiration
- internal jugular vein (IJV) volume
- free fluid in pleural or peritoneal spaces
- pulmonary edema
- tension pneumothorax
- the pipe: the vessels
- abdominal aortic aneurysm (AAA) or dissection
- thoracic aortic aneurysm or dissection
- lower limb deep vein thrombosis (DVT) (as a source of pulmonary embolus (PE))
Findings
Features seen in hypovolemic shock include:
- hypercontractile heart
- small heart size
- flat IVC and IJV
- pleural or peritoneal blood
- ruptured AAA
- aortic dissection
Features seen in cardiogenic shock include:
- hypocontractile heart
- dilated heart size
- distended IVC and IJV
- lung rockets (B-line): echogenic fan pattern of artifact in the lung due to pulmonary edema
- pleural or peritoneal fluid (effusions, ascites)
Features seen in obstructive shock include:
- pericardial effusion
- RV strain
- hypercontractile heart
- distended IVC and IJV
- pneumothorax
- DVT
Features seen in distributive shock include:
- hypocontractile heart (in late sepsis)
- hypercontractile heart (in early sepsis)
- normal or fat IVC and IJV
- pleural empyema
- peritoneal fluid (peritonitis)