What is the Rush protocol in Point-of-Care Ultrasound (POCUS)?

The RUSH Protocol in Point-of-Care Ultrasound (POCUS)

The RUSH (Rapid Ultrasound for Shock and Hypotension) protocol is a systematic, multi-organ ultrasonographic approach designed for rapid evaluation of critically ill patients with undifferentiated shock or hypotension, allowing clinicians to quickly identify the underlying cause and guide immediate management decisions.

Overview of the RUSH Protocol

The RUSH protocol follows a structured approach examining three main components:

• The Pump: Cardiac evaluation to assess contractility, pericardial effusion, and chamber size 1, 2
• The Tank: Assessment of intravascular volume status (IVC), extravascular fluid collections (FAST exam, pleural spaces), and pneumothorax 1, 3
• The Pipes: Evaluation of major vessels including aorta for aneurysm/dissection and deep veins for thrombosis 1, 2

Clinical Utility and Implementation

Diagnostic Accuracy

• POCUS consistently improves the sensitivity of standard diagnostic pathways to detect conditions such as congestive heart failure, pneumonia, pulmonary embolism, pleural effusion, and pneumothorax 4
• When added to standard diagnostic pathways, POCUS leads to statistically significantly more correct diagnoses in patients with dyspnea than standard diagnostic pathways alone 4
• The RUSH protocol has demonstrated high diagnostic accuracy for identifying various shock etiologies, with particularly strong performance in diagnosing obstructive shock (100%), cardiogenic shock (96.3%), and hypovolemic shock (94.4%) 5

Time Efficiency

• The RUSH protocol is designed to be performed in under two minutes at the bedside 2
• Studies show that POCUS examination using protocols like RUSH typically takes around 12 minutes (range 11-14 minutes) 5
• Adding POCUS to standard diagnostic pathways can lead to shorter time to diagnosis (40 vs. 60 minutes) 4

Specific Components of the RUSH Examination

Cardiac Assessment ("The Pump")

• Evaluate for pericardial effusion/tamponade 1, 6
• Assess left ventricular function and contractility 6
• Evaluate right ventricular size and function for signs of pulmonary embolism 6
• Assess valve motion and gross abnormalities 3

Volume Status Assessment ("The Tank")

• Inferior vena cava (IVC) diameter and collapsibility to assess volume status 6, 3
• FAST (Focused Assessment with Sonography in Trauma) views to detect free fluid in peritoneal, pleural, and pericardial spaces 1, 3
• Lung ultrasound to detect pneumothorax, pleural effusions, and B-lines (suggesting pulmonary edema) 6

Vascular Assessment ("The Pipes")

• Abdominal aorta evaluation for aneurysm or dissection 2
• Deep venous thrombosis (DVT) assessment of femoral and popliteal veins 1, 3

Clinical Applications and Benefits

• Rapid Diagnosis: POCUS protocols like RUSH enable early identification of shock etiology, facilitating prompt and appropriate interventions 5
• Monitoring Response: Can be used to monitor response to interventions such as fluid resuscitation 6
• Fluid Management: Helps identify fluid responders through parameters like IVC collapsibility and velocity-time integral (VTI) changes with passive leg raise 6
• Procedural Guidance: Facilitates safer performance of procedures like central line placement 4

Limitations and Considerations

• POCUS should not replace comprehensive echocardiography when detailed cardiac assessment is needed 4
• Image quality may be inferior compared to high-end systems, particularly in difficult patients 4
• Operators must be aware of their limitations and refer for comprehensive imaging when needed 4
• Studies rarely report on indeterminate sonography results, and evidence on adverse outcomes of false-positive or false-negative POCUS results is limited 4

Training and Implementation

• Appropriate training is essential for accurate interpretation and clinical application 4
• Different components of the protocol require varying levels of training and expertise 4
• The European Association of Cardiovascular Imaging emphasizes that operators must understand the limitations of focused cardiac ultrasound examinations 4

Alternative POCUS Protocols

• ACES (Abdominal and Cardiothoracic Evaluation with Sonography): Another common protocol for evaluating critically ill patients 1
• SHoC (Sonography in Hypotension and Cardiac Arrest): A hierarchical approach based on disease incidence 3
• ABCDs of ResUS (Resuscitation Ultrasound): A systematic head-to-toe approach that includes airway assessment in addition to components similar to RUSH 1

The RUSH protocol provides a structured framework for rapid assessment of critically ill patients with shock or hypotension, enabling clinicians to quickly identify the underlying cause and guide immediate management decisions. When properly implemented, it can significantly improve diagnostic accuracy and potentially impact patient outcomes.