Patient safety is the top goal of every medical facility. Sometimes, however, it is easy to overlook minor problems that may, in turn, affect the safety of a patient. When it comes to ultrasound, there are unfortunately a high number of potential oversights concerning the working order of the probe. In our experience at Axess Ultrasound, 75% of all service calls are probe-related. This is because they are constantly damaged, misused, and improperly handled, and only an average of 25 to 30% are tested and evaluated on an annual basis. Studies estimate that approximately 25%, or 150,000, of probes currently in use in the United States have defects! Some hidden internal defects may alter the probe’s performance, resulting in faulty Doppler measurements that may not be obvious to the sonographer and clinician.
The probe is the interface between the patient’s anatomy and the ultrasound system—it’s ultimately a data transfer device. If the probe collects and transfers bad data to the system due to probe defects, then the system will deliver bad data. Probe problems make a difference: Depending on their severity, a real clinical misdiagnosis can result. This is why we’re proposing a patient-centered approach to probe management.
Clinical Risks of Defective Probes
Probes are becoming more and more complex, with new technologies such as single-crystal arrays, 3D/4D, and multiplexed electronics. With these advances, however, also come electronic problems, increased testing challenges, and more expensive repairs and replacements due to the higher costs of probes and replacement parts. Ultrasound probes and systems are now used in a wide range of new clinical applications such as musculoskeletal, oncology, and podiatry. The clinical risks of bad probes are many, including Doppler flow sensitivity, spectral broadening, lower peak velocity, Mitral valve irregularities, missed soft plaque, and increased scan time. Even seemingly small issues with the lens, strain relief, or cabling can cause serious clinical and safety issues if left unattended.
So, what can you do in order to minimize damage and lower repair or replacement costs? For general imaging probes, be mindful of impact damage from accidentally dropping the probe. We are all human, but if you drop a probe, inspect it immediately to evaluate if any obvious damage has occurred. If you notice that something seems off when the probe is in use, you should have it inspected by an expert. We also recommend that you regularly visually inspect your probe for punctures of the lens, torn cables and strain reliefs, and connector damage.
For TEE probes, not using a bite guard is the number one cause of damage, for obvious reasons—the probe goes down patients’ throats and their instinct is to bite down, which causes bite marks and puncture holes in the rubber casing of the probe. This could lead to a whirlwind of problems down the road as more moisture seeps inside the probe, causing corrosion or electrical difficulties. With regard to patient safety, this damage poses a huge risk of electrical shock if the probe remains in use.
Oversoaking the probe in disinfectant is also a common cause of damage. Cidex disinfection of probes should typically not exceed 20 minutes. Although our instinct is that the longer we disinfect something, the cleaner it will be, that is not the case with ultrasound probes. Be sure to always read and follow the OEM’s approved cleaning agents list and follow it. Improper cleaning agents could cause more damage in the long run, as some of them will actually cause cracking or swelling of the lens membranes and rubber seals.
Cost-Effective “Probe Programs”
Not only do defective probes compromise patient safety, but they can also negatively affect your facility’s finances. When a probe is down, there is a real loss of revenue. That’s why we recommend taking the following steps to create a proactive, cost-effective probe repair program at your facility.
1) Get an accurate inventory of your probes.
2) Gather as much data as possible. Review the number of incidents over the last few years, examine repairs and exchanges, and get the cost per incident, if at all possible.
3) Build a serial number database by probe model, which allows for tracking repairs on specific serial numbers to determine replacement time.
4) Baseline your probe inventory to establish the current state of your inventory.
5) Categorize your probes according to their purpose, such as general imaging, TEE, 3D/4D, or nonimaging.
6) Get the proper test equipment: an electrical current leakage meter, tissue phantom, element test device (if feasible), and a handheld magnifier device.
7) Include all probes on your PM checklist, and record each time you perform a repair on the system.
8) Always perform a good visual inspection of all your probes.
9) Make sure your TEE users conduct a leakage test before performing each disinfection.
10) Consistently ask the sonographers if they are having any issues with the probes.
11) Document any findings and plan for the repair or exchange of the probe if needed.
Most probes will run forever if properly cared for and handled. However, problems do occur. Knowing when to replace a probe is also key to cutting costs in your probe program. Most probes can be repaired multiple times, except in the following cases:
1) Cable jacket cuts or tears: These can occur a maximum of three times before a new cable is required.
2) Retermination of arrays: Only one repair can be done on a retermination.
3) Weak arrays: Once an array reaches its minimum sensitivity, it needs to be replaced.
4) Complete fluid infiltration: If significant fluid infiltration occurs on a TEE probe, the moisture may corrode the inside of the probe so severely that it requires replacement of major components, including flexible circuits, coaxial cables, mechanical assemblies, and crystal arrays. In some cases, the damage is so extensive that the probe cannot be repaired and must be replaced.
The probe is a very expensive, yet vital, part of the ultrasound system. It is important to conduct regular and proper inspections to catch minor defects early on and get them corrected. This will not only ensure that your probe performs an accurate diagnosis, but will also reduce costs for your facility in the long run. Minor repairs are much less expensive than a major repair, or replacing a probe that has remained in operation after a minor problem continued to get worse. You can be a hero for your hospital and develop an internal program that will significantly cut costs with regard to your ultrasound probe repair spend.
Bob Broschart is the director of technical services at Axess Ultrasound. For more information, contact chief editor Jenny Lower at [email protected].