Point-of-Care Ultrasound (POCUS)

Point-of-care ultrasound (POCUS) answers one question at a time, such as free fluid, lung sliding or cardiac filling. It is time-critical only when a fast answer changes the next intervention.

POCUS answers one question per look. The operator hunts for the one finding that changes management right now: a pneumothorax that needs decompression, or a pericardial effusion that needs drainage. It adds to the physical exam and the monitor. It does not replace either one.

How It Works

• Focused question: Each view answers one question. Free fluid, lung sliding, pericardial fluid or cardiac filling. Know which one before you look.
• Sound and echo: Ultrasound bounces off tissue interfaces. Lung sliding shows up as movement at the pleural line. Air blocks the view of anything deeper.
• Repeatability: A negative look is a snapshot, not a verdict. Repeat it after any change in condition, after each intervention and after each move.
• Clinical integration: Read every finding against the vitals, ECG, capnography and exam. Never on its own.

Where It Fits

The RUSH exam (Rapid Ultrasound in SHock) sorts shock into the pump (heart), the tank (volume: IVC, abdomen, pleura) and the pipes (vessels). The eFAST adds lung sliding to the trauma FAST views. In arrest, ultrasound supports CPR. It looks for reversible causes (the H's and T's) during brief pauses, and it never stretches those pauses.

AHA 2025 Part 9 covers POCUS in the ALS setting. Follow your local protocol and medical direction.

Indications

• Undifferentiated shock or hypotension: Sort it into pump, tank and pipes with the RUSH framework.
• Blunt or penetrating trauma: Run the eFAST for pericardial fluid, free intraperitoneal fluid and pneumothorax.
• Dyspnea or hypoxemia: Use lung sliding, B-lines and consolidation to separate the causes.
• Cardiac arrest: Brief looks for pericardial effusion, pneumothorax, hypovolemia and cardiac activity, once the indicated life-saving interventions are done in traumatic arrest.

Absolute Contraindications

Nothing rules it out when the exam is indicated. The probe is not a reason to delay a time-critical treatment.

Relative Contraindications & Cautions

• Wound or dressing at the probe site: Switch to another window, or lay a sterile barrier down first. Pressing on an open wound is off the table.
• Poor windows: Obesity, subcutaneous emphysema, bandages, chest tubes and packaging limit the views you get.
• Operator without training: Untrained hands on a deteriorating patient. A negative or unclear read does more harm than no read at all.

Abort / Stop Criteria

• Pulse check or CPR pause that has reached 10 seconds: resume compressions and finish the look later.
• Any defibrillation, decompression or drainage that is due: perform it first.

Team Roles During the Procedure

• Operator: chooses the view and reads the image; announces findings.
• Compressor: maintains compressions and manages the pause clock.
• Airway and oxygen: keeps ventilation and monitoring going.
• Recorder: time-stamps each view and each finding.

Anatomic Difficulty

Physiologic Risk

Scan at the decision points. In hypotension, a scan earns its pause when the answer changes the next step. Is it tamponade, tension, hemorrhagic physiology or pump failure? Let the clinical picture guide which one you chase.

Site / Device Check

• Machine: curvilinear (abdomen, lung) and phased-array (heart) probes; set depth and gain before the pause.
• Preset: cardiac, abdominal or lung presets; confirm each view by orientation marker.
• Patient: exposed chest and abdomen with a gel barrier; keep compressions and ECG pads clear.

Subxiphoid View

1. Position: supine, head slightly up; probe at the xiphoid, marker to the patient's right.
2. Angle: keep the probe nearly flat against the abdomen, aimed toward the left shoulder; rock to find the four-chamber view.
3. Look: fluid around the heart, RA and RV collapse, and gross cardiac motion.
4. Confirm: sweep to find the effusion edge before calling it free fluid.

Pediatric

Same windows, with a smaller, higher-frequency probe where you have one. This page gives no pediatric thresholds.

RUQ and LUQ (FAST Abdomen)

1. RUQ: mid-axillary line, rib space above the liver and the kidney; look for fluid between liver and kidney.
2. LUQ: posterior axillary line; look for fluid around spleen and kidney and the diaphragm.
3. Pelvis: suprapubic; look for fluid posterior to the bladder. A full bladder is the acoustic window; scan before placing a Foley when possible.
4. Sweep: keep the probe on the same plane and look for the most dependent fluid.

Lung Views

1. Probe: linear probe on the anterior 2nd to 3rd intercostal space at the midclavicular line; compare sides.
2. Look: pleural line sliding with breathing (normal) or absent sliding (concern for pneumothorax; absence is non-specific).
3. Scan: move to the lateral chest and the bases to find the edge of sliding (lung point).
4. Interpret: B-lines, consolidation and pleural effusion with the clinical picture.

Equipment

Patient Positioning & Preparation

No log-roll is needed for the FAST and cardiac views, RUQ and LUQ included. Keep the patient supine. If a window is poor and there is no spinal concern, a slight tilt can help. Keep compressions on a firm surface.

Phase 1: Prepare

1. Name the question: free fluid, pneumothorax, pericardial fluid, cardiac filling or arrest cause.
2. Set the preset: cardiac, abdominal or lung preset with the matching probe.
3. Protect the team: confirm the compressor, the pause clock and the recorder.

Phase 2: Perform

4. Start with the views the question needs: for shock, RUSH order; for trauma, eFAST order.
5. Scan each window briefly: one or two sweeps, saved as a still image or clip.
6. Look for the answer: fluid, sliding, cardiac motion or consolidation.
7. Stop at 10 seconds in arrest: resume compressions and continue the look after the next cycle.
8. Act on the finding: a pneumothorax needs decompression or chest tube; a tamponade needs pericardiocentesis or surgery per local protocol.

Phase 3: Confirm & Secure

9. Record the findings: time, view, side, and the one-line impression.
10. Repeat the scan: after each intervention or change in condition.
11. Hand off: state what was scanned, what was not, and the next scan due.

Alternative Technique: Lung Sliding Only

Suspect a pneumothorax and need only the lung? Scan the anterior and lateral chest on both sides with a linear probe. Compare the sides before you call sliding absent.

Primary Confirmation

A clear image, labeled with its view, and the finding written down. For lung sliding, look again on both sides with the probe on the same site.

Secondary Confirmation

• Clinical match: the finding should fit the vitals, breath sounds, EtCO₂ and trend.
• Second view: the same finding in a second window (for example RUQ and LUQ).
• Definitive test when available: CT, echo or chest X-ray per protocol.

Ongoing Monitoring

• Repeat the look after each intervention or change in vitals.
• Continuous ECG, capnography and BP (per monitor).
• Re-scan after transport moves and before handoff.

Pediatrics

• Same views, with a smaller, higher-frequency probe where you have one.
• This page gives no pediatric thresholds for volume or effusion size. Follow pediatric protocols.
• A 2026 systematic review and GRADE meta-analysis of pediatric blunt abdominal trauma rated the evidence very low. It made no recommendation for FAST to identify clinically important intra-abdominal injury.
• Link: Pediatric cardiac arrest, Pediatric shock, Equipment sizing.

Older Adults

• A thinner chest wall, and more gas or bowel distension, may limit the windows you get.
• Pleural and cardiac findings still need to be matched to the clinical picture.

Pregnancy

• Relieve aortocaval compression with left lateral tilt or manual uterine displacement. Supine hypotension can look like shock.
• The gravid uterus can crowd out the RUQ and LUQ views.
• A negative FAST does not rule out uterine or fetal injury. Obtain obstetric assessment and fetal monitoring per protocol.
• In maternal arrest, do not let an ultrasound look delay CPR or perimortem delivery guidance.

Obesity

• You need a deeper field here. Use a curvilinear probe at a lower frequency.
• Negative windows are less reliable. Repeat the look or use another test.

Trauma and Spinal Precautions

• Scan supine, with spinal precautions in place. The RUQ and LUQ windows are done supine at the mid to posterior axillary line and need no log-roll.
• Only a true posterior chest or back window needs a log-roll. Those windows are not part of eFAST, so do not add movement for them.

Immediate Aftercare

• Document each view and the findings before moving the patient.
• Re-scan after each intervention and after any change in rhythm.

Ongoing Maintenance

• Repeat the look at intervals set by the team, and after each treatment.
• Keep the probe clean and gel changed between patients.

Transport Considerations

• Vibration and noise limit image quality; rely on the monitor and clinical trend.
• Re-scan after each move, not only at the start.
• Lung sliding and B-line reads are less reliable in motion; confirm on the ground when possible.

Pearls

• One question, one look: Pick the single decision first, then let one view answer it.
• Lung sliding rules out pneumothorax at that site: Absent sliding is the cue to correlate clinically and look again.
• Pauses are the cost: A 10-second look is 10 seconds of compressions you did not deliver.
• Negatives are provisional: A negative is a time stamp, not a finding for the rest of the call. Repeat the look as the picture changes.

Common Pitfalls

• Scanning every view in arrest. Ask one question per pause and stop there.
• A negative FAST is not a clearance. Repeat it and correlate with the picture.
• Mistaking pleural fluid for pericardial, or epicardial fat for effusion. Check how it sits against the aorta and get a second view.
• Waiting on an image before decompression. Treat first.

Skill Maintenance

• Practice the pause clock with a manikin during CPR training.
• Review saved images at debriefs and compare with the final diagnosis.
• Confirm the local credentialing and quality review requirements.