Point-of-Care Ultrasound (POCUS) Revolutionizes Emergency Medicine, One Scan at a Time
- Jenna Laquerre, BS, RT (R), RDMS (PS, AB, OB/GYN, BR), RVT
- Mar 27
- 7 min read
Point-of-Care Ultrasound (POCUS) has transformed the way clinicians assess and manage patients in real time, bringing diagnostic imaging directly to the bedside. No longer confined to radiology suites, ultrasound has become an extension of the physical exam, empowering healthcare providers with instant, actionable data. Whether in the emergency department, ambulance, or ICU, POCUS serves as a tool that enhances clinical decision-making, expedites treatment, and ultimately improves patient outcomes. Its ability to provide immediate, dynamic imaging has redefined the standard of care, making it an indispensable skill for modern healthcare professionals.
What is POCUS?
POCUS refers to the use of portable ultrasound devices at the patient's bedside to answer specific clinical questions in real-time. Unlike traditional ultrasound examinations performed in dedicated imaging departments, POCUS is integrated into the clinical evaluation, allowing for immediate correlation with the patient's symptoms and physical findings. This immediacy facilitates rapid decision-making, which is particularly important in emergency and critical care settings.
Scope and Applications of POCUS
POCUS can be implemented across medical disciplines. In emergency medicine, the ICU, and pre-hospital settings, it is a useful tool where rapid, real-time imaging can mean the difference between life and death. In the emergency department (ED), it aids in trauma assessment and guides interventions such as chest tube placements, evaluating cardiac function in hemodynamically unstable patients, and detecting free fluid in cases of internal bleeding. In the intensive care unit (ICU), POCUS helps monitor critically ill patients by assessing fluid status, guiding resuscitation efforts, and detecting life-threatening conditions such as pneumothorax or cardiac tamponade. On the scene of an accident, first responders and emergency personnel can use portable ultrasound devices to quickly assess internal injuries, identify potential shock states, and prioritize transport decisions. Its portability, speed, and accuracy make POCUS a wonderful tool in high-stakes environments where immediate clinical decisions are required.
Imaging Protocols in POCUS
POCUS relies on standardized protocols to ensure consistent, accurate, and rapid assessments in critical situations. Four widely used protocols include FAST (Focused Assessment with Sonography for Trauma) designed to check for internal bleeding in trauma cases, eFAST (Extended Focused Assessment with Sonography for Trauma) which builds on FAST by adding lung views to detect pneumothorax and pleural effusion, RUSH (Rapid Ultrasound for Shock and Hypotension) for identifying the cause of shock, and BLUE (Bedside Lung Ultrasound in Emergency) for diagnosing respiratory failure. Let's take a look at each:
Focused Assessment with Sonography for Trauma (FAST)
FAST is a rapid bedside ultrasound exam used in trauma settings to detect free fluid in the peritoneal, pericardial, and pelvic cavities. It is useful in unstable trauma patients where quick decision-making is required to determine the need for surgical intervention.
Sonographic Views & Images Acquired:
Right Upper Quadrant (RUQ) – Morison’s Pouch
Structures: Liver, right kidney, diaphragm
Purpose: Detects free fluid between the liver and kidney
Indicator of Injury: Anechoic fluid in Morison’s pouch suggests hemoperitoneum
Left Upper Quadrant (LUQ) – Splenorenal Recess
Structures: Spleen, left kidney, diaphragm
Purpose: Detects free fluid between the spleen and kidney
Indicator of Injury: Anechoic fluid in the splenorenal recess suggests hemoperitoneum
Pelvic View – Pouch of Douglas (Rectovesical Space in Males, Vesicouterine in Females)
Structures: Bladder, uterus (if female), rectovesical space
Purpose: Detects free fluid accumulation in the lowest dependent area of the abdomen
Indicator of Injury: Free fluid in the pelvis suggests intraperitoneal bleeding
Subxiphoid or Parasternal Long View – Pericardial Assessment
Structures: Heart, pericardium
Purpose: Identifies pericardial effusion or cardiac tamponade
Indicator of Injury: Anechoic fluid around the heart suggests hemopericardium, which can indicate cardiac tamponade
Extended Focused Assessment with Sonography for Trauma (eFAST)
The eFAST exam is an extension of the FAST exam, incorporating lung views to assess for pneumothorax in trauma patients. It is designed to quickly detect free fluid (suggesting hemorrhage) and air abnormalities (suggesting pneumothorax) in patients with blunt or penetrating trauma.
Sonographic Views & Images Acquired:
Right Upper Quadrant (RUQ) – Morison’s Pouch
Structures: Liver, right kidney, diaphragm
Purpose: Detects free fluid between the liver and kidney
Indicator of Injury: Anechoic fluid in Morison’s pouch suggests hemoperitoneum
Left Upper Quadrant (LUQ) – Splenorenal Recess
Structures: Spleen, left kidney, diaphragm
Purpose: Detects free fluid between the spleen and kidney
Indicator of Injury: Anechoic fluid in splenorenal recess suggests hemoperitoneum
Pelvic View – Pouch of Douglas (Rectovesical Space in Males, Vesicouterine in Females)
Structures: Bladder, uterus (if female), rectovesical space
Purpose: Detects free fluid accumulation in the lowest dependent area of the abdomen
Indicator of Injury: Free fluid in the pelvis suggests intraperitoneal bleeding
Subxiphoid or Parasternal Long View – Pericardial Assessment
Structures: Heart, pericardium
Purpose: Identifies pericardial effusion or cardiac tamponade
Indicator of Injury: Anechoic fluid around the heart
Lung Views – Pneumothorax Assessment
Structures: Pleural line, lung fields
Purpose: Identifies lung sliding (or absence of it)
Indicator of Injury: Absent lung sliding with a lung point suggests pneumothorax
Sample eFAST Protocol:
Obtain RUQ view, assessing Morison’s pouch for free fluid.
Obtain LUQ view, assessing the splenorenal recess.
Obtain pelvic view, assessing for free fluid.
Obtain subxiphoid view, assessing for pericardial effusion.
Obtain bilateral anterior lung views, looking for pneumothorax.
If free fluid or pneumothorax is detected, immediate communication with the trauma team is required.
U.S. Naval Forces Central Command/U.S. Fifth Fleet, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons
RUSH (Rapid Ultrasound in Shock):
The RUSH exam evaluates the heart, inferior vena cava, Morison's pouch, aorta, and lungs to determine the cause of hypotension and shock. It follows the "Pump, Tank, Pipes" approach:
Pump (Heart) – Evaluates cardiac function
Tank (Intravascular Volume Status) – Assesses IVC and peritoneal spaces
Pipes (Vascular System) – Examines large vessels for aneurysm, DVT, or obstruction
Sonographic Views & Images Acquired:
Cardiac Views (Subxiphoid or Parasternal Long/Short Axis)
Purpose: Evaluates left ventricular function, pericardial effusion, or right heart strain (suggesting pulmonary embolism)
Indicator of Injury: Hypokinetic LV = cardiogenic shock, Pericardial effusion = tamponade
Inferior Vena Cava (IVC) Assessment (Subcostal View, Longitudinal Plane)
Purpose: Determines volume status and fluid responsiveness
Indicator of Injury: Collapsed IVC (<2 cm) suggests hypovolemia, Dilated IVC (>2 cm, no collapse) suggests fluid overload
Abdominal Aorta Assessment (Transverse & Longitudinal Views at Midline)
Purpose: Detects abdominal aortic aneurysm (AAA)
Indicator of Injury: Aorta > 3 cm suggests AAA, > 5 cm may indicate rupture risk
FAST Exam (RUQ, LUQ, Pelvic)
Purpose: Detects intraperitoneal free fluid, suggesting hemorrhagic shock
Lung Views (Anterior and Posterior Thorax, Using Lung Protocols)
Purpose: Evaluates for pneumothorax, pleural effusion, pulmonary edema
Sample RUSH Protocol:
Assess the heart (Pump) for function and effusion.
Assess the IVC (Tank) for volume status.
Assess the aorta (Pipes) for aneurysm.
Perform an eFAST exam for intra-abdominal bleeding.
Assess the lungs for pneumothorax or pleural effusion.
Findings help differentiate types of shock:
Hypovolemic shock: Small IVC, free fluid
Cardiogenic shock: Poor LV contractility
Obstructive shock: Tamponade, pneumothorax, massive PE
Distributive shock: Hyperdynamic heart, normal IVC
BLUE (Bedside Lung Ultrasound in Emergency):
The Bedside Lung Ultrasound in Emergency (BLUE) protocol is specifically designed to assess lung sliding, B-lines, consolidations, and pleural effusions for evaluating acute respiratory failure.
Sonographic Views & Images Acquired:
Anterior Chest – Upper and Lower Blue Points (Bilateral Lung Fields)
Purpose: Identify lung sliding, A-lines, B-lines
Findings:
A-lines only: Normal lung or pneumothorax
B-lines: Pulmonary edema, interstitial syndrome
Hepatization of the lung: Suggests pneumonia
Anechoic pleural fluid: Suggests effusion
Absent lung sliding + A-lines: Pneumothorax
Absent lung sliding + Consolidation: Pneumonia
Lateral Chest – PLAPS (Posterolateral Alveolar and/or Pleural Syndrome) View
Purpose: Assess for pleural effusion, pneumonia, lung consolidation
Findings:
Hepatization of the lung: Suggests pneumonia
Anechoic pleural fluid: Suggests effusion
Absent lung sliding + A-lines: Pneumothorax
Absent lung sliding + Consolidation: Pneumonia
Posterior Chest – Lower Blue Points (Near Diaphragm)
Purpose: Evaluate for effusions or atelectasis
Findings:
Absent lung sliding + A-lines: Pneumothorax
Absent lung sliding + Consolidation: Pneumonia
Sample BLUE Protocol:
Assess bilateral anterior lung zones (upper/lower BLUE points) for pneumothorax or interstitial syndrome.
Assess posterolateral lung fields (PLAPS) for consolidation or pleural effusion.
Assess posterior lung fields for atelectasis or fluid accumulation.
Findings help differentiate causes of respiratory distress:
Pneumothorax: No lung sliding, A-lines only
Pulmonary edema: B-lines bilaterally
Pneumonia: Hepatization, consolidation
Pleural effusion: Anechoic fluid
Diagnostic Targets of POCUS
POCUS is used to detect an array of conditions, including but not limited to:
Cardiac: Pericardial effusion, cardiac tamponade, ventricular dysfunction, and cardiac standstill in cardiac arrest.
Pulmonary: Pneumothorax, pleural effusion, pulmonary edema, and lung consolidation in respiratory failure.
Abdominal: Free intraperitoneal fluid in trauma, ruptured abdominal aortic aneurysm (AAA), and bowel obstruction.
Vascular: Deep vein thrombosis (DVT) in unstable patients and ultrasound-guided vascular access in critical resuscitations.
Importance and Benefits of POCUS
The integration of POCUS into clinical practice offers many benefits:
Enhanced Diagnostic Accuracy: POCUS augments physical examination findings, leading to more precise diagnoses.
Immediate Clinical Decision-Making: Real-time imaging allows for prompt interventions, which is very important in acute settings.
Procedure Guidance: POCUS increases the safety and success rates of various bedside procedures by providing visual guidance.
Patient Safety: By reducing the need for patient transport and exposure to ionizing radiation, POCUS contributes to a safer patient experience.
Responding to Critical Findings
When emergency medical personnel or a sonographer identifies a critical finding during a POCUS examination, immediate action is required:
Communicate Promptly: Inform the clinical team without delay to facilitate swift clinical decisions.
Document Thoroughly: Accurately record the findings, including images and measurements, to support clinical correlation and future reference.
Assist in Management: Be prepared to aid in any immediate interventions or procedures that may be necessitated by the findings.
Timely communication ensures that critical findings lead to appropriate and rapid patient care interventions.
Conclusion
POCUS represents a transformative advancement in patient care, offering immediate, bedside diagnostic capabilities that supplement clinical assessment and decision-making. POCUS protocols and applications broadens the skill set of medical personnel and contributes to improved patient outcomes. Embracing ongoing education and training in POCUS will help you to fully harness its potential in the ever-evolving landscape of medical imaging.
Want to learn more? Check out the POCUS segment of our Abdomen Webinar Series! This session explores POCUS applications in emergency medicine, covering trauma assessments and critical care scenarios.
🔗 Explore our video series and more at www.prepry.com!
References:
American College of Emergency Physicians. (2019). ACEP policy statement: Emergency ultrasound guidelines. Annals of Emergency Medicine, 74(3), 470-482. https://www.acep.org/siteassets/new-pdfs/policy-statements/ultrasound-guidelines--emergency-point-of-care-and-clinical-ultrasound-guidelines-in-medicine.pdf
Fraleigh, C. D. M., & Duff, E. (2022). Point-of-care ultrasound: An emerging clinical tool to enhance physical assessment. The Nurse practitioner, 47(8), 14–20. https://doi.org/10.1097/01.NPR.0000841944.00536.b2
Lichtenstein, D. A. (2016). Lung ultrasound in the critically ill: The BLUE protocol. Springer. https://link.springer.com/book/10.1007/978-3-319-15371-1
Perera, P., Mailhot, T., Riley, D., & Mandavia, D. (2010). The RUSH exam: Rapid Ultrasound in Shock in the evaluation of the critically lll. Emergency medicine clinics of North America, 28(1), 29–vii. https://doi.org/10.1016/j.emc.2009.09.010
Rose, J. S., Bair, A. E., Mandavia, D., & Kinser, D. J. (2001). The FAST is not enough: Identifying patients with major torso trauma using the extended FAST (eFAST) examination. Journal of Trauma and Acute Care Surgery, 50(3), 476-479. https://doi.org/10.1097/00005373-200103000-00019
Shen-Wagner, J., & Deutchman, M. (2020). Point-of-care ultrasound: A practical guide for primary care. Family Practice Management, 27(6), 33-40.
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