POCUS, peer influence, competence, and patient safety
I have noticed something interesting in the emergency department.
One physician becomes comfortable with POCUS.
They pick up the probe during a resuscitation. They find the heart quickly. They show the IVC. They look at the lungs. The team watches.
Soon, another physician wants to scan. Then another.
Most of the time, this is a very good thing. Curiosity spreads. People learn from each other. POCUS becomes part of the culture.
But sometimes I notice something different.
It feels as though simply holding the probe has become a way of demonstrating competence.
Someone else is scanning, so I should scan too.
Someone else can show the heart, so I should be able to show it.
Someone else makes an interpretation, so I should make one too.
I don’t think this necessarily comes from ego or bad intentions. Medicine is a social profession. We watch our colleagues, compare ourselves with them, and learn from them.
Peer comparison can affect how learners judge themselves. In an experiment using written scenarios, medical students estimated their future performance differently depending on the peer described. This offers a possible explanation for shifts in confidence, but it does not show how competition affects POCUS skill or patient safety. Raat et al., 2013
In my view, competition can motivate ultrasound learners when it is used constructively and keeps attention on learning together.
So competition is not necessarily the problem.
The problem begins when the desire to look competent moves faster than the process required to become competent.
POCUS competence: holding the probe is only the beginning
POCUS is unusual because competence is very visible.
When somebody interprets an ECG, much of the reasoning happens internally.
When somebody reviews blood results, nobody watches the analytical process.
Ultrasound is different.
Everybody sees the probe in your hand.
Everybody sees an image appear on the screen.
And when somebody says:
“No pericardial effusion.”
“LV looks good.”
“No B-lines.”
“FAST is negative.”
“IVC is collapsible.”
…it sounds convincing.
But what the rest of the team cannot easily see is everything happening behind that statement.
Was the correct view obtained?
Was the image diagnostic?
Was enough of the organ examined?
Was the gain appropriate?
Could the finding be an artifact?
Was a normal variant mistaken for pathology?
Was pathology mistaken for normal?
Does this POCUS application have sufficient sensitivity to exclude the condition we are worried about?
And, most importantly:
Should this finding actually change what we do to the patient?
That is where POCUS becomes more than image acquisition.
Competence involves preparing for the examination, obtaining and optimizing images, interpreting them and integrating the result into care. UCAT assesses these skills using an entrustment-based approach. Its initial evaluation involved 37 trainees performing a simulated FAST examination, so it provides early validity evidence in that setting rather than proof of competence across all POCUS applications. Bell et al., 2021
In practice, I would assess competence through direct observation, case discussion, image review and structured assessment, using logbooks to document experience rather than treating any one measure as sufficient.
What sits behind POCUS competence?
1. Prepare
Define the clinical question and choose the examination.
2. Acquire and optimize
Obtain diagnostic views and adjust the image.
3. Interpret
Identify findings, artifacts and limitations.
4. Integrate
Decide what the result means for this patient.
Across every skill: supervised practice, saved images, feedback and reassessment.
The “normal scan” may worry me more than the abnormal one
This is something I have become increasingly conscious of in practice.
When a novice finds something obviously abnormal, people often stop and think.
A large pericardial effusion.
A severely reduced LV.
Free fluid in Morison’s pouch.
Diffuse B-lines.
We ask someone else to look. We correlate with the patient. We consider additional imaging.
But sometimes the more dangerous statement is:
“It is normal.”
Because a confident negative study can close the diagnostic process.
Imagine a technically inadequate cardiac examination followed by:
“Heart is normal.”
Or a limited FAST followed by:
“No bleeding.”
Or a poorly obtained lung examination followed by:
“No pulmonary edema.”
The problem is not that the clinician used ultrasound.
The problem is that uncertainty was converted into certainty.
Incorrect interpretation can lead to false reassurance or inappropriate treatment. This is why image quality, interpretation and clinical integration all deserve attention.
During procedures, having an ultrasound image on the screen can also create a false sense of security if the operator cannot reliably identify the relevant anatomy or track the needle. Structured education and supervised practice remain essential.
This is an important lesson:
Not seeing pathology is not the same as proving that pathology is absent.
Sometimes the correct POCUS interpretation is simply:
“I cannot answer this question adequately with these images.”
| Statement that overreaches | A more precise alternative |
|---|---|
| “The heart is normal.” | “These views are limited; I cannot adequately assess cardiac function.” |
| “FAST is negative, so there is no bleeding.” | “No free fluid was identified in the views obtained. This does not exclude bleeding.” |
| “The lung scan excludes pulmonary edema.” | “This examination is technically inadequate to answer that question.” |
That sentence does not demonstrate weakness.
It demonstrates maturity.
The next step matters too. After major trauma, a negative FAST cannot exclude abdominal or retroperitoneal bleeding. If hemorrhage remains a concern, continue the trauma assessment and resuscitation; do not use FAST to decide whether CT is needed or let it delay indicated CT. NICE major trauma guidance.
Confidence is not the enemy
I also do not think we should turn this discussion into:
“Experienced doctors are safe, inexperienced doctors are dangerous.”
That would be simplistic.
Every expert was once a beginner.
And nobody becomes competent without scanning patients.
The solution cannot be telling novice physicians:
“Don’t touch the probe.”
We should be saying:
“Take the probe. Scan. Save the images. Show me what you see. Tell me what you think it means. Then let’s review it together.”
That is how competence develops.
A safe training pathway includes supervised practice, targeted feedback, competency assessment, skill maintenance and quality assurance.
Until competence has been demonstrated for the relevant POCUS application, learners should have their examinations and interpretations reviewed before using them independently to guide patient care. Independent practice should also follow the institution’s credentialing and privileging requirements.
ACEP’s 2023 ultrasound guidelines similarly place training, proficiency, credentialing and quality management within the infrastructure required for clinical ultrasound practice. ACEP ultrasound guidelines, 2023
That is the culture I would like to see.
Not less scanning.
More supervised scanning.
Not less enthusiasm.
More feedback.
Not less confidence.
Confidence that has been tested against competence.
What could we do differently in the ED?
If I were developing a departmental POCUS culture, I would make a few principles very clear:
- Separate learning from independent decision-making. Let people scan early and often, but make it clear when an examination is educational, supervised, or suitable for independent clinical interpretation.
- Save the images. If a POCUS finding contributes to a meaningful diagnosis or treatment decision, image archiving makes feedback and quality assurance possible.
- Review both positive and negative scans. We learn a great deal from spectacular pathology, but reviewing apparently “normal” examinations is equally important because that is where inadequate views and false reassurance may hide.
- Assess more than image acquisition. Ask the learner: Why did you scan? What does the image show? How certain are you? What are the limitations? What will you do differently because of this finding?
- Normalize uncertainty and second opinions. “Limited study,” “I am not sure,” and “Can you look at this with me?” should be signs of a safe POCUS culture, not signs of weakness.
- Make competition collaborative. Instead of competing over who scans the most, build a department that takes pride in image quality, diagnostic accuracy, case discussion, feedback and improving together.
Quality assurance needs a clear route back to patient care. I would assign responsibility for reviewing saved studies, giving feedback and promptly escalating a discrepancy that could change management. A useful review includes the indication, image quality, interpretation and clinical decision, not just whether an attractive image was obtained. ACEP ultrasound guidelines, 2023.
The goal of QA should not be:
“Who made the mistake?”
It should be:
“What can all of us learn from this scan?”
A course alone is not competence
This also changes how I think about POCUS certification.
A weekend course can be valuable.
Lectures are valuable.
Simulation is valuable.
Textbooks are valuable.
But none of them alone can demonstrate that somebody is ready to independently use POCUS to change patient management.
For me, appropriate training requires competence in both real-time acquisition and interpretation. Reading a textbook or reviewing selected images should complement supervised experience examining patients across a range of disease processes.
For me, certification should therefore not answer only:
“Did you attend the course?”
or:
“Did you complete the required scans?”
It should eventually answer a much more important question:
“Can I trust you to perform this examination, recognize its limitations, interpret it correctly and use the result safely in patient care?”
Scan counts document experience; they do not replace assessment. I would want direct observation, discussion of difficult cases and review of saved studies before deciding how much supervision a learner needs. Bell et al., 2021; ACEP, 2023.
The probe should be a tool, not a badge
I still want the physician standing next to me to become interested when they see me using ultrasound.
Actually, I hope they do.
I want them to say:
“Can you teach me?”
And I want to hand them the probe.
But after they obtain the image, I also want to ask:
“What do you see?”
“How good is this image?”
“What could you be missing?”
“How confident are you?”
“And does this finding really change what we should do?”
Because POCUS is not ultimately about obtaining beautiful images.
It is about making better decisions for patients.
The most experienced POCUS clinician in the room is not necessarily the person who reaches for the probe first.
It may be the person who knows when to scan, how to scan, how much to trust the result — and when to say that the scan is not enough.
So I don’t want to discourage the spread of POCUS.
I want exactly the opposite.
But as POCUS spreads, our standards for education, supervision and quality assurance must spread with it.
The goal is not simply to put an ultrasound probe in every physician’s hand.
The goal is to make sure that when that probe changes a clinical decision, the person holding it has the competence to understand what the image shows — and what it does not.
POCUS should spread. Competence must spread with it.
References and further reading
- Raat ANJ, et al. Peer influence on students’ estimates of performance: social comparison in clinical rotations. Medical Education. 2013;47(2):190–197. doi:10.1111/medu.12066.
- Bell C, et al. The Ultrasound Competency Assessment Tool (UCAT): Development and Evaluation of a Novel Competency-based Assessment Tool for Point-of-care Ultrasound. AEM Education and Training. 2021. doi:10.1002/aet2.10520.
- American College of Emergency Physicians. Ultrasound Guidelines: Emergency, Point-of-care, and Clinical Ultrasound Guidelines in Medicine. 2023.
For a practical approach to image quality and bedside interpretation, read our step-by-step cardiac POCUS guide.
