Bedside Ultrasound in the Emergency Department
The first thing to accept about ultrasound in the emergency department is counter-intuitive: what it gives is a first impression, not a final diagnosis. Whether it is used well rarely depends on how high the specifications are; it depends on two things - how quickly it can be running at the bedside, and whether the user understands what it looks like when the view is not reliable.
1. What bedside ultrasound does in the emergency department
In accepted clinical use, bedside ultrasound in the emergency department covers the things that need to be seen:
- Identifying and locating fluid in a body cavity (peritoneal, pleural, pericardial)
- Supporting the assessment of pneumothorax (looking at lung sliding and related signs)
- Observing cardiac activity and making a rough assessment of volume status
- Guidance while establishing vascular access (internal jugular, subclavian, peripheral veins)
- A rapid assessment sequence in trauma patients, scanning in a fixed order of views
- Guidance for bedside procedures (locating fluid for drainage, assessing a superficial abscess, and so on)
What these have in common: the question is specific, the answer is needed quickly, and the result is used to decide the next action - whether to insert a needle, whether to transfer, whether to call a senior colleague. It does not take on systematic examination, and it does not replace the full assessment done on a fixed system.
2. Common uses and the probes they need
| Use | Usual probe | What the device needs |
|---|---|---|
| Pericardial and pleural fluid | Phased array / convex | Depth reaching a step of 160 mm or more; cardiac mode frequencies |
| Peritoneal fluid, trauma assessment | Convex | The full set of convex depth steps (of the 90 / 160 / 220 / 305 mm kind) |
| Assessing pneumothorax | High-frequency linear | Superficial resolution; enough to see dynamic signs such as lung sliding |
| Guiding vascular access | High-frequency linear | Superficial depth steps (of the 20-55 mm kind) plus a needle guide |
| Observing cardiac activity | Phased array / cardiac mode | Cardiac mode frequencies and the corresponding depth steps |
3. Why the emergency department tends to use handheld or portable systems
Not because the specifications are higher, but for three workflow reasons:
- Time to be ready. A handheld system has the whole machine in the probe handle: take it out, connect the display, and scan. A portable unit is unpacked and positioned within tens of seconds. A trolley suits a fixed examination room; pushing it between floors to the bedside does not save time.
- Space. In a resuscitation bay the machine has to fit between the trolleys. A trolley system at about 20 kg net is awkward to turn in that space, whereas a handheld probe can be operated with one hand.
- Power. On a handheld device the battery is in the probe: the 5 series common data gives about 3 hours (individual models differ) and about 2-3 hours to charge. Portable units have a built-in battery giving 1.5 hours or more up to 2 hours or more of continuous scanning. In the emergency department, power should be planned around the length of a shift, not around a single examination.
Where the department also has a fixed ultrasound room, the usual arrangement is to use both together: a handheld or portable system at the bedside for the first impression, and the fixed system when a systematic assessment is needed. That is a division of work, not one replacing the other.
4. Four boundaries that matter more than specifications
This is the most important section of the article. Bedside ultrasound is mostly misused not because of the equipment, but because "not seen" gets treated as "not there".
- A negative result does not exclude the problem. Take trauma assessment: a single rapid scan showing no fluid does not exclude injury - gas, position and too little scanning time all cause findings to be missed. The value of a negative scan is that, taken with the clinical picture, it can lower certain risks; it is not that the problem has been excluded.
- Write limited views as they are; do not write "no abnormality seen". Where gas, body habitus or position limit the view, record "not clearly visualised" and say why, rather than writing a general normal.
- One scan records that moment only. The condition changes, and an image from a few hours ago does not represent the present. Repeat the scan when the clinical picture changes.
- It supports; it is not the end point of the judgement. Final management combines history, signs, laboratory results and other imaging, and is decided by a qualified physician. The equipment and the image do not in themselves constitute a diagnosis.
5. How to write the record
The value of a bedside ultrasound record often only shows when the case is reviewed afterwards. Three suggestions:
- Record the time and the position: images of the same patient at different times can only be compared if the time is marked.
- Record the view and the probe: "subcostal four-chamber view, phased array" is far more useful than "cardiac ultrasound, no abnormality".
- Record the limitations: marked gas interference, a dressed wound, restricted position - all of these belong in the record. They explain why the image looks the way it does.
6. Common questions
Q: Does an emergency department have to have a handheld system? Is one trolley enough?
A: It depends on the space and the workflow. Where the resuscitation area is tight and bedside work is frequent, a handheld or portable system is more practical; where there is a fixed examination room and little bedside demand, one trolley system can cover it. Most departments use the two together rather than only one.
Q: Does a handheld battery last a shift?
A: On the published data, a 5 series handheld probe runs for about 3 hours of uninterrupted scanning, with individual models differing (about 1 hour for 5PA, about 2.5 hours for 5T), and takes about 2-3 hours to charge. Within a shift it will usually need a top-up or a spare probe; arrange this according to how heavily the department actually uses it, and do not plan on the basis of "one charge covers a day".
Q: Does bedside ultrasound need a dedicated probe cover?
A: Where a sterile procedure is involved (guiding vascular puncture or a body cavity puncture, for example), a probe cover and sterile gel are needed to sterile requirements; ordinary surface examination follows routine cleaning. Follow your institution's infection control rules.
Q: How should images be handed on to the next shift?
A: A handheld device can store images on the phone or tablet and file them by patient and time; a portable unit can store them on board and export them. Hand them on together with the time, the views and the limitations - that is more useful than handing over the images alone.
Related reading
- Landmark Versus Ultrasound-Guided Puncture: Where Each One Fits
- Ultrasound-Guided Central Venous Access: Internal Jugular and Subclavian Vein Approaches
- Handheld ultrasound
This article is intended as reference for healthcare professionals and does not constitute clinical guidance. Interpretation and management in bedside ultrasound should be decided by a licensed physician with the relevant qualifications, taking the patient's actual condition into account. The equipment data quoted is taken from the technical documentation; the actual scope of application is the one stated in the product registration certificate, and contraindications and precautions are set out in the instructions for use.
