Point-of-Care Ultrasound (POCUS)

Medical Disclaimer: This article is for general educational purposes only and does not constitute medical advice. Lab values must always be interpreted in the context of your individual clinical situation by a qualified physician. Do not make any medical decisions based solely on this article.

A practical introduction to one of the most powerful tools in modern bedside medicine.

What Is POCUS?

Point-of-care ultrasound — POCUS — is the use of ultrasound imaging performed and interpreted by the treating clinician at the patient’s bedside, in real time, to answer a specific clinical question.

Unlike a formal radiology ultrasound, which is performed by a sonographer, interpreted by a radiologist, and returned as a report hours later, POCUS is immediate. The physician holds the probe, acquires the images, and integrates the findings directly into the clinical assessment — right now, while the patient is in front of them.

POCUS has transformed the practice of medicine across emergency medicine, critical care, and increasingly, hospital medicine. It is not a replacement for formal imaging — it is an extension of the physical examination.

Why POCUS Matters in Hospital Medicine

As a hospitalist, POCUS allows me to answer critical clinical questions at the bedside without waiting for formal imaging or transporting an unstable patient to the radiology suite. In a fast-moving hospital environment, real-time information changes management — sometimes dramatically.

A patient presenting with shortness of breath: Is there fluid around the heart? Is the left ventricle contracting normally? Is there a pleural effusion? POCUS can answer all three questions within minutes of the patient arriving.

A patient with hypotension: Is the inferior vena cava collapsed, suggesting volume depletion? Or is the heart squeezing poorly, pointing toward cardiogenic shock? These are entirely different diagnoses requiring entirely different treatments. POCUS directs the answer.

A patient whose IV access has failed: POCUS-guided peripheral IV placement dramatically improves first-attempt success in patients with difficult veins.

The ability to see inside the patient — in real time, without radiation, at the bedside — is one of the most significant advances in clinical medicine of the past two decades.

Core POCUS Applications in Internal Medicine and Hospital Medicine

Cardiac (Focused Echocardiography)

The cardiac POCUS exam evaluates the heart’s structure and function at a fundamental level. Key questions include:

• Is the left ventricle (LV) contracting normally, hyperdynamic, or severely reduced?

• Is there a pericardial effusion (fluid around the heart)? Is there evidence of tamponade physiology?

• Is the right ventricle (RV) dilated — a finding that raises concern for pulmonary embolism?

• Are the valves grossly normal?

Standard windows: parasternal long axis (PLAX), parasternal short axis (PSAX), apical four-chamber (A4C), subxiphoid (subcostal).

Pulmonary

Lung ultrasound is counterintuitive at first — ultrasound does not penetrate air well, which is precisely why the artifacts it generates are clinically informative.

• A-lines: Horizontal reverberation artifacts indicating normal aeration

• B-lines: Vertical artifacts (“comet tails”) that indicate interstitial fluid — present in pulmonary edema and interstitial pneumonia

• Pleural effusion: Anechoic (dark) fluid above the diaphragm

• Pneumothorax: Absence of lung sliding — a sensitive finding for air in the pleural space

• Consolidation: Tissue-like appearance of lung — seen in pneumonia or atelectasis

Abdominal / FAST Exam

The Focused Assessment with Sonography in Trauma (FAST) exam evaluates for free fluid in the peritoneal cavity and pericardium. In non-trauma settings, abdominal POCUS is used to assess for ascites, hepatomegaly, splenomegaly, hydronephrosis, and gallbladder pathology including gallstones and signs of cholecystitis (wall thickening, pericholecystic fluid, sonographic Murphy’s sign).

IVC Assessment

Evaluation of the inferior vena cava (IVC) diameter and its collapsibility with respiration provides a non-invasive estimate of intravascular volume status. A small, collapsing IVC suggests volume depletion. A large, non-collapsing IVC suggests elevated right-sided pressures or volume overload. IVC assessment is most useful when interpreted alongside the rest of the clinical picture.

Vascular Access

POCUS-guided IV access has become standard of care for patients with difficult peripheral veins. Ultrasound allows real-time visualization of the vessel, the needle, and surrounding structures — dramatically improving success rates and reducing complications compared to blind landmark-based techniques. POCUS guidance is also standard for central venous catheter placement.

DVT Assessment

Lower extremity venous compression ultrasound evaluates the femoral and popliteal veins for deep vein thrombosis. The key finding is non-compressibility of the vein — a normal vein collapses completely under probe pressure, while a thrombosed vein does not. POCUS DVT assessment in high-pretest-probability patients is a powerful clinical tool that can accelerate anticoagulation decisions.

Bladder

Bladder POCUS rapidly estimates post-void residual volume and can detect urinary retention — a common, uncomfortable, and often underrecognized condition in hospitalized patients.

Soft Tissue

POCUS can distinguish cellulitis from a subcutaneous abscess — a distinction that is clinically important because abscesses require incision and drainage while cellulitis does not. The “cobblestoning” appearance of edematous subcutaneous tissue distinguishes cellulitis, while a hypoechoic fluid collection with posterior acoustic enhancement indicates an abscess.

Learning POCUS — Where to Start

POCUS is a procedural skill. Like any procedural skill, it requires supervised hands-on practice to develop competency — reading about it is necessary but not sufficient. Here is a structured approach to getting started:

Step 1 — Learn the physics and knobology. Understanding how ultrasound works — transducer frequency, depth, gain, focus — is foundational. You need to know how to optimize your image before you can interpret it. Resources: Emergency Ultrasound by Ma and Mateer (textbook), or the free online course at SonoSim.

Step 2 — Choose your starting application. Don’t try to learn everything at once. Start with one application — cardiac POCUS is a common starting point in internal medicine. Master it before moving to the next.

Step 3 — Practice on normal patients first. Scan your colleagues. Scan yourself. Normal anatomy is the foundation for recognizing pathology. You cannot recognize an abnormal IVC if you have never seen a normal one.

Step 4 — Seek supervised scanning opportunities. Find an attending or fellow with POCUS expertise at your institution and ask to scan alongside them. Many academic programs now have dedicated POCUS educators. Emergency medicine and critical care rotations are often excellent environments for supervised POCUS practice.

Step 5 — Use image review and quality assurance. Many institutions have POCUS image archives and quality review programs. Submitting your images for review — and receiving feedback — accelerates competency development.

Essential POCUS Resources

Textbooks and References:

• Point-of-Care Ultrasound by Soni, Arntfield, and Kory — the gold standard comprehensive POCUS textbook for internists and intensivists

• Emergency Ultrasound by Ma and Mateer — foundational text, excellent for cardiac and abdominal applications

• The Core Ultrasound Handbook — concise, practical, well-organized for quick reference

Online and App-Based Learning:

• POCUS Atlas (pocusatlas.com) — free, extensive image library organized by application; invaluable for learning normal and abnormal findings

• 5MinuteEcho (5minuteecho.com) — focused cardiac ultrasound tutorials, excellent for internists

• Grepmed POCUS — curated images and diagrams

• SonoSim — simulation-based POCUS learning platform used by many residency programs

• iPoint-of-Care (iPoC) — mobile app with POCUS protocols and reference images

• Butterfly iQ — the Butterfly iQ probe is a single-probe, whole-body handheld ultrasound device that connects directly to a smartphone or tablet. Beyond the hardware, the Butterfly app includes a built-in education library, guided scanning tutorials, and AI-assisted image interpretation — making it one of the most accessible entry points into POCUS for trainees and practicing clinicians alike. The Butterfly iQ+ is increasingly present in hospital medicine programs and is worth familiarizing yourself with early. butterfly-network.com

Podcasts and Video:

• The Ultrasound Podcast — one of the most popular POCUS podcasts; engaging, practical, and appropriate for all levels

• ACEP POCUS Academy — free video library from the American College of Emergency Physicians

• Bedside Ultrasound (YouTube) — high-quality instructional videos organized by application

Courses and Certification:

• CHEST Critical Care Ultrasound Course — a highly regarded intensive course for pulmonary and critical care applications

• ACEP Emergency Ultrasound Course — a foundational course widely attended by EM and IM physicians

• Society of Hospital Medicine POCUS Certificate of Completion — a formal recognition program designed specifically for hospitalists, with structured curriculum and image submission requirements

• ACP POCUS Track — the American College of Physicians offers a dedicated POCUS learning track through its educational programs, tailored specifically to internal medicine physicians and trainees. A natural fit for anyone pursuing POCUS within the IM framework. acponline.org

• Gulf Coast Ultrasound Institute — one of the most well-regarded dedicated ultrasound training centers in the country, offering hands-on courses ranging from introductory to advanced across cardiac, vascular, abdominal, and musculoskeletal applications. Courses are available for physicians at all levels of experience and are particularly valued for their intensive hands-on format. gcus.com

POCUS in Hospital Medicine — The Future Is Now

Hospital medicine was slower than emergency medicine and critical care to embrace POCUS — but that is changing rapidly. The Society of Hospital Medicine has developed a formalized POCUS curriculum and certificate program for hospitalists, and residency programs are increasingly incorporating POCUS training into their internal medicine curricula.

If you are a medical student or resident, learning POCUS now is an investment that will pay dividends throughout your career. If you are a practicing hospitalist considering adding POCUS to your skillset, the resources and formal training pathways have never been more accessible.

The bedside ultrasound probe is becoming what the stethoscope was to the previous generation of physicians — an extension of the clinician’s senses, available at every bedside, in every patient encounter.

Learn to use it.

— Dr. Joyce Cheng, MD, MPH, MHA, FACP, Internal Medicine Hospitalist | Clinical Assistant Professor

This page is intended for educational purposes for medical trainees and healthcare professionals. It does not constitute clinical guidance for individual patient care.