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References

1. Lee L, DeCara JM. Point-of-Care Ultrasound. Curr Cardiol Rep. 2020;22(11):149. doi:1007/s11886-020-01394-y
2. Razi R, Estrada JR, Doll J, Spencer KT. Bedside Hand-Carried Ultrasound by Internal Medicine Residents Versus Traditional Clinical Assessment for the Identification of Systolic Dysfunction in Patients Admitted with Decompensated Heart Failure. Journal of the American Society of Echocardiography. 2011;24(12):1319-1324. doi:1016/j.echo.2011.07.013
3. Islam SKMS, Nasim MAA, Hossain I, Ullah MA, Gupta KD, Bhuiyan MMH. Introduction of Medical Imaging Modalities. arXiv. Preprint posted online June 7, 2023:arXiv:2306.01022. doi:48550/arXiv.2306.01022
4. Lanspa MJ, Fox SW, Sohn J, et al. Definitive Advantages of Point-of-Care Ultrasound: A Case Series. CASE. 2022;6(6):293-298. doi:1016/j.case.2022.05.008
5. AMERICAN COLLEGE OF EMERGENCY PHYSICIANS, Pediatric Emergency Medicine Committee. Ultrasound Guidelines:  Emergency, Point-of-Care, and Clinical Ultrasound Guidelines in  Medicine. 2016.
6. Burton L, Bhargava V, Kong M. Point-of-Care Ultrasound in the Pediatric Intensive Care Unit. Front Pediatr. 2022;9:830160. doi:3389/fped.2021.830160
7. Lewis D, Rang L, Kim D, et al. Recommendations for the use of point-of-care ultrasound (POCUS) by emergency physicians in Canada. CJEM. 2019;21(6):721-726. doi:1017/cem.2019.392
8. McLario DJ, Sivitz AB. Point-of-Care Ultrasound in Pediatric Clinical Care. JAMA Pediatr. 2015;169(6):594. doi:1001/jamapediatrics.2015.22
9. Osterwalder J, Polyzogopoulou E, Hoffmann B. Point-of-Care Ultrasound—History, Current and Evolving Clinical Concepts in Emergency Medicine. Medicina. 2023;59(12):2179. doi:3390/medicina59122179
10. Health Canada. Guidelines for the Safe Use of Diagnostic Ultrasound. Published online 2001.
11. Nowicki A. Safety of ultrasonic examinations; thermal and mechanical indices. Med Ultrason. 2020;22(2):203. doi:11152/mu-2372
12. Hoskins PR, Martin K, Thrush A, eds. The British Medical Ultrasound Society. Guidelines for the safe use of diagnostic ultrasound equipment. In: Diagnostic Ultrasound. 2nd ed. Cambridge University Press; 2010:217-225. doi:1017/CBO9780511750885.020
13. Shankar H, Pagel P. Potential Adverse Ultrasound-related Biological Effects. Anesthesiology. 2011;115(5):1109-1124. doi:1097/ALN.0b013e31822fd1f1
14. FUJIFILM SonoSite, Inc. Sonosite PX User Guide. Published online 2025.
15. AIUM Official Statement: Guidelines for Cleaning and Preparing External‐ and Internal‐Use Ultrasound Transducers and Equipment Between Patients as Well as Safe Handling and Use of Ultrasound Coupling Gel, 2025 Revision. J of Ultrasound Medicine. 2025;44(12). doi:1002/jum.70014
16. Abo AM, Alade KH, Rempell RG, et al. Credentialing Pediatric Emergency Medicine Faculty in Point-of-Care Ultrasound: Expert Guidelines. Pediatr Emer Care. 2021;37(12):e1687-e1694. doi:1097/PEC.0000000000001677
17. Marin JR, Lewiss RE, AMERICAN ACADEMY OF PEDIATRICS, Committee on Pediatric Emergency Medicine, et al. Point-of-Care Ultrasonography by Pediatric Emergency Medicine Physicians. Pediatrics. 2015;135(4):e1113-e1122. doi:1542/peds.2015-0343

PoCUS is a powerful clinical tool that can enhance patient assessment, support clinical decision-making, and improve procedural safety. However, its effectiveness depends not only on image acquisition and interpretation, but also on understanding its appropriate role, limitations, and safe integration into patient care.

 

Key takeaways

• PoCUS is an adjuvant of clinical assessment, designed to answer focused clinical questions and complement (not replace) the history, physical examination, and clinical judgment.
• PoCUS is most effective when applied within a clinical context to evaluate specific syndromes, guide procedures, and support timely patient management.
• PoCUS has diagnostic limitations. A negative or inconclusive PoCUS examination does not necessarily exclude disease. Findings should always be interpreted in conjunction with the patient’s clinical presentation.
• Be sure to remember when PoCUS Is NOT ENOUGH. Recognizing high-risk scenarios, technically limited examinations, and situations requiring formal imaging or specialist consultation is an essential component of safe PoCUS practice.
• Although ultrasound has an excellent safety record, clinicians should minimize acoustic exposure by using the lowest output and follow the ALARA principle
• Machine settings matter. Understanding factors that influence TI, MI, and overall acoustic exposure helps clinicians make informed decisions and use ultrasound safely.
• Clear documentation, image archiving, and effective communication of findings support patient care, quality assurance, and clinical accountability.
• Competency requires more than theoretical knowledge and is developed through structured training, supervised practice, assessment, quality assurance, and continued clinical use.

 

Safe PoCUS practice requires balancing the strengths of bedside ultrasound with an awareness of its limitations. By integrating ultrasound findings with the overall clinical picture, adhering to safety principles, maintaining competency, and seeking additional imaging or consultation when appropriate, clinicians can use PoCUS responsibly and effectively to improve patient care.

PoCUS is a skill that requires structured training and ongoing practice. Competence is not achieved through didactic teaching alone and should not be assumed based solely on course completion or theoretical knowledge. As a responsible PoCUS user, it is important to ensure adequate training, maintain competency, and recognize the limits of one’s abilities [1].

 

Competence in PoCUS extends beyond image acquisition and include the ability to:

A) Understand the clinical indications for the examination.

B) Have the skill to acquire diagnostic-quality images.

C) Have the ability to accurately interpret images.

D) Integrate findings into clinical decision-making.

[5, 7, 16, 17]

 

Competency is developed through a progression of didactic learning, supervised practice, longitudinal mentorship, formal assessment, quality assurance, and continued clinical use. Together, these components support the development of the knowledge, technical skills, image interpretation abilities, and clinical judgment required for safe and effective PoCUS practice.

Assuming competence without adequate training, assessment, and feedback can increase the risk of image acquisition errors, misinterpretation of findings, overconfidence in limited examinations, and inappropriate clinical decision-making.

 

 

Figure 8.  PoCUS training workflow

PoCUS findings should be documented clearly, concisely, and in a way that directly answers the clinical question being asked. Documentation should communicate what was examined, what was found, and how those findings influenced clinical decision-making [7]. The goal is not to provide a comprehensive radiology report, but rather a focused assessment that reflects the scope of the examination performed. Appropriate documentation and image archiving are essential components of safe, accountable PoCUS practice.

 

Use Clear, Binary Language

Whenever possible, PoCUS findings should be documented using simple, binary statements that answer the clinical question.

Examples:

· No pericardial effusion identified.

· Large right pleural effusion present.

· No sonographic evidence of hydronephrosis.

· Intrauterine pregnancy visualized.

This approach reduces ambiguity and aligns with the focused nature of PoCUS examinations.

 

Link Findings to the Clinical Question

Documentation should clearly connect the examination findings to the reason the scan was performed.

Examples:

· Clinical question: Is there a large pericardial effusion contributing to hypotension?

· Documentation: No pericardial effusion identified.

· Clinical question: Is pulmonary edema contributing to dyspnea?

· Documentation: Bilateral diffuse B-lines identified, consistent with an interstitial syndrome.

 

Acknowledge Uncertainty and Limitations

Not every examination provides a definitive answer. Poor acoustic windows, patient factors, or limited views may reduce diagnostic confidence. When uncertainty exists, it should be documented clearly.

Examples:

· Study limited by child cooperation.

· Image quality suboptimal.

· Unable to adequately visualize the appendix.

· Indeterminate study. Formal imaging required.

Documenting limitations is a strength, not a weakness. Recognizing uncertainty helps prevent overinterpretation and reduces the risk of false reassurance.

 

Avoid Overstatement

PoCUS is designed to answer focused clinical questions and may not reliably exclude all pathology. Documentation should reflect the scope of the examination performed. A negative PoCUS finding does not necessarily exclude disease.

Avoid statements such as:

“Normal abdomen.”

“No intra-abdominal pathology.”

“Heart normal.”

Instead, document only what was assessed:

No free fluid identified on FAST examination.

No large pericardial effusion identified.

No hydronephrosis visualized.

 

Figure 7. Example of a thorough chart documentation after PoCUS exam

 

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Quality Assurance, Image Archiving, and Accountability

Whenever possible, PoCUS examinations should be archived and available for review. Image archiving supports quality assurance processes, facilitates feedback and education, allows findings to be reviewed in the context of future patient care, and has medico-legal considerations [7]

Saved images should include any relevant labels (e.g left/right, affected/unaffected), image orientation (transverse/longitudinal).

Clinicians remain accountable for the interpretation and documentation of PoCUS findings. Documentation should accurately reflect the examination performed, the findings obtained, and any limitations that may affect interpretation.

 

For additional guidance on image saving and archiving workflows, please revisit the KidSONO Knobology module content and instructional videos

 

Despite the importance of PoCUS documentation and image archiving, common barriers include perceived time constraints, lack of certification, and concerns about litigation [6]. These perceived barriers should NOT prevent clinicians from chart documentation and archiving representative images, as both are essential components of quality assurance, patient care, and professional accountability.

Infection Control and Equipment Stewardship

For safe PoCUS use, clinicians are also responsible for maintaining appropriate infection control practices and ensuring ultrasound equipment is handled and maintained correctly.

 

Infection Control

Ultrasound machines and probes should be cleaned and disinfected before and after each patient encounter. This includes both the transducer and machine surfaces that are frequently touched during scanning, such as the keyboard, controls, screen, handles, and cart. Although cleaning and disinfection may be overlooked in busy clinical environments, particularly when PoCUS is used in emergent situations, maintaining appropriate infection prevention and control practices remains the responsibility of every user. Visible blood, body fluids, or other contamination should always be cleaned immediately. Even when contamination is not apparent, routine cleaning and disinfection should be performed regularly. The level of cleaning and disinfection depends on the intended use of the transducer and the risk of infection transmission associated with the examination or procedure (Figure 4).

 

Figure 4. AIUM recommendations for transducer preparation, probe cover use, gel selection, and post-procedure disinfection requirements based on the type of ultrasound examination and level of tissue contact. LLD = low-level disinfection; HLD = high-level disinfection; IVUS = intravascular ultrasound; TEE = transesophageal echocardiography. Source: American Institute of Ultrasound in Medicine (AIUM), 2025 [15].

 

Key Points for Equipment Infection Control & Stewardship

· Use probe covers and sterile gel when indicated by the procedure or patient population.

> Sterile gel is recommended for neonatal imaging, and for examinations involving mucous membranes (endovaginal, endotracheal) or immunocompromised patients [7].

· Clean and disinfect equipment using approved products/wipes in accordance with local policies and manufacturer/local guidelines;  and never spray directly onto the equipment [14].

· If available, use high-level disinfection when indicated following invasive procedures.

· Handle probes and cables carefully to prevent damage; store probes in their designated holders.

· Take care not to run over transducer cables with the machine, chairs, or other equipment

· Inspect equipment for damage or image-quality problems and report concerns according to local procedures.

· Return portable/handheld devices to charging stations when examinations are complete

 

 

Figure 5. (a)Probe cover and (b)sterile gel

 

Figure 6. A ) Damaged probe and B) Imaging artifact from broken crystal 

Ultrasound Safety & ALARA

The information presented in this section is based primarily on Health Canada’s Guidelines for the Safe Use of Diagnostic Ultrasound (2001) [10]. Where applicable, additional sources have been cited to supplement or update specific recommendations.

 

Foundations of Ultrasound Safety

Diagnostic ultrasound has an excellent safety record and does not use ionizing radiation. However, ultrasound transfers energy into tissues and, under certain conditions, may produce biological effects. Understanding these effects helps clinicians use ultrasound safely.

Ultrasound energy can interact with tissue through two primary mechanisms: thermal effects and mechanical effects.

 

1) Thermal Effects

Thermal effects occur when tissues absorb ultrasound energy and convert it to heat. The amount of heating depends on both the ultrasound exposure and the type of tissue being scanned.

Bone absorbs ultrasound energy more readily than soft tissue, while fluids absorb very little. As a result, temperature increases are of greater concern when bone is present within the ultrasound beam, including fetal bone during pregnancy. Because bone absorbs ultrasound energy efficiently, less acoustic power is required to produce a temperature rise than in soft tissue [11].

Heat may also be generated by the transducer itself. Additional caution may be warranted during transvaginal, transrectal, and transesophageal examinations, as transducer heating may contribute to local tissue warming. Similar considerations apply when bone is located close (within 1cm) to the transducer surface, such as during cranial imaging.

 

2) Mechanical Effects

Mechanical effects are non-thermal interactions caused by pressure changes within the ultrasound wave. The primary concern is cavitation, which refers to the response of gas bubbles exposed to alternating pressure cycles. Cavitation may occur as stable cavitation, where bubbles repeatedly expand and contract, or inertial cavitation, where bubbles grow and collapse rapidly [11].

In routine diagnostic ultrasound, cavitation is considered unlikely in most tissues because naturally occurring gas bubbles are generally absent. The theoretical risk is greater in tissues containing gas, such as the lungs or bowel, and when ultrasound contrast agents containing microbubbles are used.

 

Figure 1. Ultrasound safety basics

 

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Machine Parameters

Several parameters influence ultrasound exposure and are displayed on modern ultrasound systems.

Dwell Time

Dwell time refers to the amount of time the transducer actively transmits ultrasound while remaining over a particular area. Dwell time is one of the most important factors affecting tissue exposure and can be readily controlled by the operator.

Thermal Index

The Thermal Index (TI) is an indicator of the potential for tissue heating. It represents the ratio of the emitted ultrasonic power to the power required to raise tissue temperature by approximately 1°C under specific model conditions.

The TI indicator is displayed on the ultrasound screen.

Different TI’s are used depending on the tissue being examined:

· TIS (Soft Tissue):used when primarily soft tissue is within the ultrasound path.

· TIB (Bone):used when bone, including 2^nd and 3^rd trimester fetal bone, is within the beam.

· TIC (Cranial):used when bone is in contact or within 1cm of the transducer.

 

Because bone absorbs ultrasound energy more readily than soft tissue, TIB and TIC are particularly important when scanning fetal, neonatal, or cranial structures.

 

Mechanical Index

The Mechanical Index (MI) is an indicator related to the potential for mechanical effects, including cavitation. It reflects the relationship between ultrasound pressure and transducer frequency.

Modern diagnostic ultrasound systems are designed with a maximum attainable MI of 1.9, a limit intended to substantially reduce the likelihood of clinically significant mechanical injury.

The MI indicator is displayed on the ultrasound screen

 

Figure 2. MI and TIS as seen on a SonositePX PoCUS unit.

 

Output Power

Output power refers to the amount of ultrasound energy emitted by the transducer, or acoustic output. Increasing output power increases the amount of energy delivered to tissues and may increase the potential for thermal or mechanical effects.

           Scanning tip: Gain vs Output Power

Gain and output power are not the same. Gain adjusts how returning echoes are displayed on the screen and affects image brightness without increasing patient exposure.

Output power changes the amount of ultrasound energy transmitted into the patient. Increasing the power directly on the machine is not recommended.

 

B-Mode and Doppler Modes

Different imaging modes produce different levels of acoustic output.

· B-mode generally produces the lowest acoustic output.

· M-mode may produce higher outputs than B-mode.

· Color Doppler and pulsed-wave Doppler typically generate higher acoustic outputs and have a greater potential for tissue heating.

Although M-mode and Doppler are valuable clinical tools, their use should be guided by the ALARA principle, particularly when imaging sensitive tissues [12].

 

Pulse Repetition Frequency (PRF):

PRF refers to the number of ultrasound pulses transmitted by the transducer each second. PRF is most commonly adjusted during Doppler examinations and contributes to the higher acoustic outputs associated with Doppler imaging. Increasing PRF increases the number of ultrasound pulses transmitted per second and may increase acoustic exposure.

Scanning tip: On many ultrasound systems, the Doppler scale control is the user-facing adjustment for PRF. Increasing the scale typically increases the PRF, allowing higher velocities to be displayed and reducing aliasing, while decreasing the scale lowers the PRF and improves sensitivity to slower flow.

 

Frequency

Lower-frequency transducers provide greater penetration but may increase TI and MI because more acoustic energy is required to image deeper structures. Use the highest frequency that adequately answers the clinical question.

 

Focus Position

The focal zone is the region where the ultrasound beam is narrowest and most concentrated. Moving the focus deeper requires the system to concentrate energy at greater depths, which may increase TI and MI [13]. Position the focal zone at or just below the structure of interest whenever possible.

 

Scan Area

Scan area refers to the width or size of the imaging field. Reducing the scan area concentrates ultrasound energy into a smaller region and may increase TI and MI. , particularly when the zoom box is narrow and deep [13].

 

Figure 3. Parameters affecting TI/MI and overall theoretical risk of ultrasound

 

 

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ALARA and Practical Safety Behaviors

ALARA stands for As Low As Reasonably Achievable and is the guiding principle for safe ultrasound practice. The goal is to obtain the diagnostic information needed while minimizing unnecessary exposure.

In diagnostic ultrasound, ALARA refers to using the lowest combination of acoustic output and exposure time necessary to answer the clinical question [10].

 

Practical ALARA behaviors include:

· Minimize dwell time and avoid holding the transducer stationary longer than necessary.

· Remove the probe from the patient when real-time imaging is no longer required.

· Use freeze-frame and cine-loop functions to review images rather than continuing live scanning.

· Use Doppler modes only when clinically indicated.

· Restrict Doppler sampling to the area of interest by using the smallest practical Doppler box.

· Always select the pre-programmed scanning preset when possible.

· Monitor displayed TI and MI values throughout the examination.

· When monitoring TI values, consider the tissues within the ultrasound beam and use the TI indicator (TIS, TIB, TIC) that best reflects the tissue at greatest risk of heating.

· Use the lowest output settings that still provide diagnostically useful images.

 

If TI or MI values increase, exposure time should be minimized and output settings reduced whenever possible.

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Special Safety Considerations

 

Pregnancy

Ultrasound is widely used during pregnancy and has an excellent safety record. However, additional caution is recommended because the developing embryo and fetus may be more susceptible to thermal effects.

During the first eight weeks after conception, organogenesis is occurring and developing tissues may be particularly sensitive to environmental influences. The fetal brain and spinal cord continue developing throughout pregnancy and into the neonatal period [12]. As fetal bone develops, absorption of ultrasound energy increases, potentially leading to greater tissue heating.

Different TI models are therefore used throughout pregnancy:

· TIS is most relevant during early pregnancy.

· TIB becomes increasingly important once fetal bone is present within the ultrasound beam, during the 2^nd and 3^rd [11,14].

 

When scanning pregnant patients, output power and exposure time should be kept as low as reasonably achievable. Obstetric examinations are typically performed using default settings that maintain a TI <0.7. If TI exceeds 0.7, scan duration should be minimized. An MI <0.7 is also recommended [11].

Particular caution should be exercised when using Doppler modes, especially during the first trimester, as Doppler generally produces higher acoustic outputs than B-mode imaging. Routine use of color and pulsed-wave Doppler during the first trimester is generally discouraged unless there is a specific clinical indication. When Doppler is indicated, exposure time should be minimized and TI values kept as low as possible (TI <1.0, no more than 5-10 minutes) [11].

Examination of the mother’s uterine vessels safe when the fetus is outside the radiated field.

Additional caution may also be warranted when maternal temperature is elevated, as fetal temperature may be influenced by both maternal and ultrasound-related heating.

 

Ocular Ultrasound

The eye is particularly sensitive to thermal effects because the lens and intraocular fluids have limited cooling blood supply [12]. Because of this, it is essential to maintain a very low MI and TIS during ocular scanning to minimize the theoretical risk of tissue damage [11].

When performing ocular ultrasound:

· Use an ophthalmic preset when available.

· Maintain a MI of 0.23 or less.

· Maintain a TIS of 1.0 or less.

· Avoid colour and pulsed Doppler unless specifically indicated.

These precautions are particularly important in pediatric ocular examinations.

 

Neonatal and Pediatric Imaging

Additional caution is recommended when performing ultrasound examinations in neonates, infants and young children. Certain tissues and organs may be more susceptible to potential biological effects of ultrasound, either because they are still developing (such as the brain and spinal cord) or because they contain gas [12]. These considerations that are particularly relevant given the frequent use of cranial, lung, and bowel ultrasound in neonatal and pediatric practice.

When imaging pediatric patients, examinations should be clinically justified, performed efficiently, and exposure times kept as short as reasonably achievable.

 

Brain, head, and spine:

When performing neonatal transcranial or spinal ultrasound examinations, if the TIC exceeds 0.7, exposure time should be restricted, with progressively shorter scan times recommended as TIC increases.

Prolonged scanning of the central nervous system is not recommended [12].

 

Lungs:

If the MI exceeds 1.0, there is a small potential risk of capillary hemorrhage during ultrasound examinations involving the neonatal or infant chest [10].

More recent literature suggests that, in neonatal ultrasonography, there may be a potential risk of lung damage even at MI values of approximately 0.3, and that the risk of cavitation increases when MI exceeds 0.7 [11].

Scanning should therefore be as short as possible and performed in accordance with ALARA principles.

 

Bowel

The bowel is another gas-containing organ where mechanical effects are of theoretical concern. Ultrasonically induced capillary hemorrhaging of the intestine has been associated with conditions that inhibit intestinal peristalsis or promote intraluminal or submucosal gas collections. At current diagnostic ultrasound exposure limits (MI ≤ 1.9), clinically significant intestinal hemorrhage is considered unlikely; however, the likelihood may increase in pathological conditions associated with impaired intestinal motility or increased intraluminal gas [10].

 

Ultrasound Contrast Agents

Ultrasound contrast agents can contain gas-filled microbubbles that increase the potential for cavitation and other mechanical effects. As a result, additional attention should be paid to the MI when contrast agents are used, as the theoretical risk of cavitation increases in the presence of microbubbles. Although contrast-enhanced ultrasound is not routinely used in most PoCUS applications, clinicians should be aware of this consideration.

 

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Communicating Safety to Patients and Families

Patients and families may have questions about ultrasound safety, particularly during pregnancy and pediatric examinations.

When discussing ultrasound safety:

· Explain that ultrasound does not use ionizing radiation.

· Emphasize that diagnostic ultrasound has a long history of safe clinical use.

· Explain that ultrasound energy is used at levels intended to provide diagnostic information while minimizing exposure.

· Reassure that ultrasound equipment is set to operate within established safety limits, and that output settings are continuously monitored throughout the examination.

· Reassure patients that clinicians follow ALARA principles and continuously monitor safety indicators during examinations.

· If the TI or MI is greater than 1, then the patient or caregiver should be informed of the anticipated exposure condition and how it compares in safety with conditions for normal diagnostic practice [10].

 

Clear communication can help address concerns while supporting informed participation in care.

Sample script:

“Ultrasound uses sound waves rather than ionizing radiation. It has been used safely for many years, including during pregnancy and in children. We use only the amount of ultrasound energy needed to answer our clinical question and keep the exam as brief and as focused as possible. Throughout the scan, we monitor the machine’s safety indicators and adjust the settings to minimize energy delivery, keeping exposure as low as reasonably achievable.”

 

Why PoCUS has Limitations:

Although PoCUS is a powerful clinical tool, it has important limitations that must be recognized to ensure safe and appropriate use.

· Operator dependence: The quality of image acquisition, interpretation, and clinical integration depends on the skill and experience of the user. Different clinicians may obtain different images or reach different conclusions from the same examination.

· Technical limitations and poor acoustic windows: Image quality may be affected by limited penetration and poor acoustic windows. Bone, gas, obesity, cooperation, dressings, wounds, and subcutaneous air can all limit visualization of underlying structures.

· Limited field of view: PoCUS examines only the structures that are visualized during the scan. Pathology outside the scanned area may be missed.

· Incomplete or indeterminate examinations: Not all scans provide a definitive answer. Studies may be technically limited, incomplete, or indeterminate and should be documented as such.

· Limited ability to rule out disease: For many conditions, PoCUS can help identify pathology when present but cannot reliably exclude disease when absent. A negative scan does not necessarily mean a disease is not present.

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Avoiding Unsafe Clinical Decisions

One of the greatest risks in PoCUS is overconfidence in limited examinations. Ultrasound provides a real-time visual representation of internal structures, which can create a false sense of certainty and may lead clinicians to discount other important clinical information [4]. Inexperienced users may also be susceptible to the Dunning–Kruger effect, in which individuals lack the experience required to recognize the limits of their own competence [4].

Unsafe use of PoCUS commonly occurs when clinicians:

· Assume a PoCUS examination has the same sensitivity and diagnostic accuracy as a comprehensive imaging study.

· Interpret technically poor or incomplete scans as normal.

· Use negative findings to reassure themselves when caring for a clinically unwell patient.

· Fail to integrate PoCUS findings with the overall clinical picture.

· Use PoCUS findings to delay escalation of care, specialist consultation, or formal imaging.

 

For example, a normal FAST examination should not be used to dismiss ongoing hypotension in an unstable trauma patient. PoCUS findings should always be interpreted in conjunction with the patient’s history, physical examination, vital signs, and overall clinical status.

 

Recognizing the limitations of PoCUS is just as important as recognizing its strengths. Safe practitioners understand not only what PoCUS can identify, but also what it may miss and when additional investigations are required.

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When PoCUS is NOT enough

A key aspect of safe PoCUS practice is recognizing when additional imaging or consultation is required. While some focused clinical questions can be answered confidently at the bedside, other conditions require comprehensive diagnostic evaluation.

Clinicians should be particularly mindful of high-risk diagnoses, technically limited examinations, and scenarios in which a negative or inconclusive PoCUS examination may not safely exclude disease.

 

High-Risk and “Think Twice” Scenarios

Acute Surgical conditions, such as suspected appendicitis, intussusception, testicular/ovarian torsion, or small bowel obstruction

Why think twice?

A negative or inconclusive PoCUS examination may not safely exclude these diagnoses, particularly early in the disease process. Formal imaging and specialist consultation is often still required.

 

 

Poor-Quality or Incomplete Examinations

· Limited views due to bowel gas

· Obesity or challenging body habitus

· Patient movement or poor cooperation

· Incomplete image acquisition

Why think twice?

An indeterminate study should not be interpreted as a normal study.

 

 

Early Pregnancy & Suspected Early Pregnancy

Why think twice?

Early pregnancy can be particularly challenging to assess with PoCUS. In very early gestation, the gestational sac, fetal pole, or fetal cardiac activity may not yet be visible or may be difficult to identify, particularly when using PoCUS equipment with lower image resolution than formal RADUS or when image acquisition is technically limited. The absence of an identifiable intrauterine pregnancy on PoCUS should therefore be interpreted cautiously, as it may represent an early intrauterine pregnancy, pregnancy loss, a technically limited examination, or an ectopic pregnancy. Findings must be interpreted in the context of gestational age, clinical presentation, laboratory investigations, and follow-up imaging when indicated. Formal imaging and specialist consultation may still be required.

Because pulsed-wave, colour, and power Doppler use higher acoustic output and may produce greater tissue heating than B-mode imaging, they should not be used routinely in early pregnancy. Increased energy may be dangerous to the developing fetus. Apply the ALARA principle by using the lowest output and shortest dwell time required,  and using B-mode or M-mode rather than spectral Doppler to document fetal cardiac activity.

 

 

Ocular & Optic Nerve Imaging

Why think twice?

Ocular PoCUS requires additional safety considerations and careful technique. Because the eye is particularly sensitive to ultrasound energy, clinicians should be mindful of scan duration, acoustic output, and the use of Doppler modes. Additionally, optic nerve PoCUS require accurate image acquisition and measurement technique, as small errors can significantly affect interpretation and may lead to incorrect assumptions regarding intracranial pressure.

Additionally, Ocular PoCUS for suspected globe rupture is contraindicated. Pressure applied to the eye may worsen the injury. Alternative imaging and urgent ophthalmologic consultation should be pursued.

 

 

Ocular & Optic Nerve Imaging

· Extensive open wounds or burns over the area of interest

· Examinations requiring sterile technique (e.g., procedures, non-intact skin)

· Patients requiring isolation precautions

Why think twice?

These situations do not necessarily contraindicate PoCUS, but may require modifications to scanning technique or additional precautions. Scanning directly over extensive burns, open wounds, or recent surgical sites may be painful or increase infection risk. Patients requiring isolation precautions can still undergo PoCUS, but appropriate cleaning, disinfection, and probe protection measures must be followed. Similarly, coagulopathy, anticoagulation, or local infection may not contraindicate ultrasound itself, but may influence whether an ultrasound-guided procedure should proceed.

PoCUS can be applied across a wide range of clinical scenarios and specialties. While specific applications vary by profession and practice setting, most examinations are performed to answer focused clinical questions that arise during patient assessment. The American College of Emergency Physicians describes five broad areas of PoCUS practice: resuscitation, diagnosis, procedural guidance, symptom or sign evaluation, and therapeutic or monitoring applications [5].

Rather than viewing PoCUS as a collection of individual examinations, it is often helpful to consider its use within a syndrome-based framework. In practice, PoCUS is frequently integrated with clinical assessment tools, decision rules, and clinical pathways to support patient management.

Across emergency medicine, pediatrics, critical care, and generalist practice and specialties, several PoCUS applications have emerged as foundational competencies. Common examples include shock assessment, trauma assessment, focused cardiac ultrasound, thoracic ultrasound, urinary tract assessment, biliary imaging, soft tissue and musculoskeletal examinations, ocular and neural ultrasound, bowel applications and ultrasound-guided procedures [5-9].

The specific applications expected of a clinician will depend on their patient population, practice environment, training, and local scope of practice.

 

Table 1: Common Clinical Syndromes and PoCUS Applications

 

 

The Role of PoCUS

PoCUS is a focused imaging modality that can be used as an adjunct to clinical assessment. Rather than replacing clinical assessment, PoCUS complements it by providing additional bedside information that helps clinicians evaluate signs and symptoms, narrow the differential diagnosis, and rapidly answer focused clinical questions [1]. Because PoCUS can be performed wherever patient assessment occurs, it is often integrated directly into routine clinical care by physicians, residents, nurses, and allied health professionals [1].

Unlike comprehensive imaging studies, PoCUS is intentionally focused. PoCUS examinations are designed to answer specific clinical questions using a limited number of targeted views [1]. For example, a clinician may ask: Is there a pericardial effusion? Is there free fluid in the abdomen? Is hydronephrosis present or absent? By focusing on binary or relatively narrow clinical questions, PoCUS can provide rapid bedside information that supports clinical decision-making.

PoCUS offers several advantages as an adjunct to clinical assessment. It provides rapid bedside information that can support earlier diagnosis and management, including reduced time to definitive interventions [2]. Because imaging is performed in real time, findings can be immediately integrated into patient care. PoCUS is also well suited for serial examinations, allowing clinicians to monitor disease progression, treatment response, and ongoing management. Additional advantages include its relatively low cost, its ability to provide procedural guidance, potential to reduce ionizing radiation exposure in selected cases, and the ability to reduce the need for some invasive diagnostic procedures.

 

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PoCUS and Other Imaging Modalities

No single imaging modality is ideal for every clinical scenario. PoCUS should be viewed as a complementary tool that provides rapid bedside information, while formal imaging studies typically provide more comprehensive anatomical assessment. Understanding the strengths and limitations of each modality in comparison to PoCUS will help clinicians select the most appropriate investigation for the clinical question being asked.

 

PoCUS vs Radiology Ultrasound (RADUS)

PoCUS is designed to answer focused clinical questions, while radiology ultrasound provides a comprehensive diagnostic examination.

• Advantages of PoCUS / Limitations of RADUS: PoCUS can be performed immediately at the bedside and integrated directly into patient care, particularly when formal ultrasound is not immediately available (e.g., nights or weekends).
• Advantages of RADUS / Limitations of PoCUS: RADUS provides a comprehensive examination using standardized protocols, higher-end equipment, sonographer expert image acquisition and interpretation by radiologists. In contrast, PoCUS is focused, operator-dependent, and often performed using more limited equipment. PoCUS does not replace a comprehensive RADUS.
• Clinical example: PoCUS may identify hydronephrosis in a child with suspected renal colic, while RADUS would provide a more comprehensive evaluation of the kidneys and urinary tract.

 

PoCUS vs Portable X-Ray

Both PoCUS and radiography are widely available and can be obtained rapidly in many clinical settings.

• Advantages of PoCUS / Limitations of X-ray: PoCUS provides real-time imaging without ionizing radiation and allows dynamic bedside assessment. In contrast, X-rays produce a two-dimensional representation of three-dimensional anatomy, have relatively low soft tissue contrast, and are less effective at distinguishing between different tissue types [3].
• Advantages of X-ray / Limitations of PoCUS: X-rays provide excellent visualization of bones and fractures and offer a broader assessment of large anatomical regions. PoCUS is more limited in its field of view and is less suitable for evaluating osseous pathology.
• Clinical example: In a patient presenting with dyspnea, PoCUS may rapidly identify pleural effusions, pulmonary edema, or pneumothorax at the bedside, while a chest X-ray provides a broader overview of thoracic pathology. CXR is also able to detect focal or diffuse air-space opacities that do not reach the pleural surface.

 

 

PoCUS vs Computed Tomography (CT)

CT provides detailed anatomical imaging and remains the gold standard for many diagnoses.

• Advantages of PoCUS / Limitations of CT: PoCUS can be performed immediately at the bedside, provides real-time imaging, allows serial examinations, and does not expose patients to ionizing radiation or contrast agents.
• Advantages of CT / Limitations of PoCUS: CT provides high-resolution cross-sectional imaging of bones, organs, and blood vessels and offers a more comprehensive anatomical assessment with less operator dependence [3]
• Clinical example: PoCUS may rapidly identify free fluid during a trauma assessment, while CT is required to fully characterize injuries and guide definitive management.

 

 

PoCUS vs Magnetic Resonance Imaging (MRI)

MRI provides detailed soft tissue assessment without ionizing radiation.

• Advantages of PoCUS / Limitations of MRI: PoCUS is portable, inexpensive, provides real-time imaging, and can be performed immediately at the bedside without concerns related to motion, claustrophobia, or lengthy examination times.
• Advantages of MRI / Limitations of PoCUS: MRI provides high-resolution multiplanar imaging with excellent soft tissue characterization and a significantly more comprehensive evaluation of anatomy.
• Clinical example: PoCUS may identify an intracranial hemorrhage during infantile cranial ultrasound, while MRI is required for more detailed evaluation of intracranial anatomy and pathology.

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Downstream Clinical Decision Making

PoCUS findings should always be interpreted within the broader clinical context and used to guide subsequent management decisions. While PoCUS may identify important abnormalities or narrow the differential diagnosis, it does not replace formal diagnostic imaging or clinical decision making. Instead, PoCUS often helps determine which patients require additional investigations, specialist consultation, urgent intervention, or ongoing monitoring.

By providing timely bedside information, PoCUS can improve communication between healthcare providers and consulting services, facilitate appropriate referrals, and reduce the time required to reach the correct diagnosis and treatment plan [4].

Point-of-care ultrasound (PoCUS) has become an increasingly common component of clinical care since its widespread adoption in the early 2000s [1]. As access to ultrasound technology has expanded, so too has the number of clinicians incorporating PoCUS into their practice.

While much of PoCUS education focuses on image acquisition and interpretation, safe and effective use also requires an understanding of ultrasound safety, diagnostic limitations, documentation, quality assurance, and appropriate clinical integration. These principles help ensure that PoCUS findings are applied thoughtfully and within the context of the overall patient assessment.

This module provides an overview of the foundational principles that support safe, effective, and responsible PoCUS practice. Upon completion of this module, learners should be able to:

• Describe the role of PoCUS in clinical care.
• Recognize the benefits of PoCUS.
• Recognize common limitations and diagnostic boundaries of PoCUS.
• Explain the principles of ultrasound safety, including the ALARA principle.
• Understand the importance of training, competency, quality assurance, and image archiving.
• Apply best practices for documentation, communication, infection prevention, and equipment stewardship.
• Integrate PoCUS findings into safe clinical decision-making.