Nam Tran, PhD

The incidence of acute kidney injury (AKI) has been increasing in recent years, but this serious health condition remains challenging to diagnose and manage. Conventional testing is typically performed in hospital or reference laboratories, but there is a serious need to enable triage-type testing that would help first responders make key decisions about where to transport high-risk patients.

According to an analysis performed by researchers at the U.S. Centers for Disease Control and Prevention, there were nearly 4 million hospitalizations associated with AKI during 2014 in this country alone. That’s more than double the number seen in 2006, which was nearly twice the number logged in 2000. While diabetes is an established risk factor for acute kidney injury, patients without diabetes are seeing sharp increases in AKI rates as well. Studies in other countries have reported similar findings, suggesting a widespread trend for the increasing occurrence of acute kidney injury.

Acute kidney injury has also become a significant health challenge for deployed military personnel. A test that helps identify AKI on the battlefield could have major implications where at-risk personnel could be diverted to facilities that are appropriately equipped to manage renal dysfunction. Without rapid results in the field or en route to treatment facilities, there is significant risk that AKI cases may progress—resulting in serious system damage or death.

Acute kidney injury, defined as a sudden reduction in kidney function with or without the onset of kidney damage or failure, typically occurs over the course of a few hours or a couple of days. It can be brought on by a range of health conditions — from sepsis to heart attack to cancer &mdash; but can also result from a bodily trauma, such as being in a car accident, or from taking certain medications that can be toxic to kidneys.

One of the reasons this condition can be so challenging to diagnose is that symptoms tend to be non-specific, and some patients can even appear completely asymptomatic. Typical symptoms can include decreased urine output, swelling in the legs or ankles, fatigue, confusion, nausea, chest pain, and shortness of breath.

Conventional testing for AKI can be invasive or difficult. A urinalysis can report on biological markers associated with this injury, but people with severe cases may not be able to produce enough urine for testing. In some scenarios, healthcare teams will perform kidney biopsies to evaluate their function (

 transplant cases). Other diagnostic options include blood tests and imaging, though not all tests are relevant in all cases. Most of these tests must be run at a hospital’s clinical lab or a regional reference lab, which takes a substantial amount of time and can delay much-needed treatment, while the few commercially available point-of-care devices rely on less specific biomarkers of kidney function.

Among deployed military personnel, the increasing frequency of acute kidney injury can be directly linked to the rise of improvised explosive devices (IEDs). People who are wounded due to encounters with IEDs must be assessed quickly and transported to the medical facility best suited to treating their particular injuries. Acute kidney injury requires specific treatments requiring dedicated equipment, often including dialysis. When this injury is not detected during triage, military personnel may be transported to a facility that lacks the necessary equipment and therefore face higher risk of mortality due to the injury.

Military interest in a rapid diagnostic that could be used to triage injured personnel and more accurately identify cases of acute kidney injury has led to development of a portable test that can detect biomarkers associated with this injury in no more than 15 minutes. Today, that test is being evaluated for clinical use to bring rapid injury detection into the mainstream.

The new point-of-care test currently in clinical development uses sensitive, electro chemical biosensors to measure neutrophil gelatinase-associated lipocalin (NGAL) and creatinine. NGAL serves as a marker of traumatic kidney injury, while creatinine has long been considered a strong monitoring marker for kidney function. Together, these markers, when used at the point of care, provide an excellent view of kidney health.

The test is run on an easy-to-operate device that requires minimal training or technical skill, making it ideal for broad use among first responders, emergency teams, and other critical care professionals. It produces results in 10 to 15 minutes, a time frame that would allow users to make informed decisions about where to take a patient for optimal care.

Acute kidney injury is often the result of a concussive event. Though the test was first created for use in combat, its mainstream deployment would make it an invaluable addition to medical tests used for people involved in car accidents, sports injuries, or other impact events. When AKI is detected, ensuring the delivery of these patients to healthcare facilities that have dialysis and other needed equipment could save lives.

The tremendous rise in incidence of AKI highlights the need for better testing options. Currently, testing for creatinine and NGAL is often limited to hospital or regional laboratories, which take far too long to deliver results. For patients with this injury, early detection is essential in order to be transferred to the right healthcare facility and to receive life-saving treatment.

The availability of a portable, easy-to-use device that could generate results in less than 15 minutes would be a transformative development for first responders — and for the patients they serve. As the number of AKI cases continues to rise, medical teams must have every tool possible to improve the delivery of care and reduce associated complications and mortality.

David Ludvigson is President and CEO of Nanomix, a company implementing mobile, rapid diagnostic testing for critical disease states using a proprietary handheld platform. Nam Tran, PhD, is Associate Clinical Professor in the Department of Pathology and Laboratory Medicine at the University of California, Davis. The opinions expressed in the piece here are solely those of the author, and do not reflect those of the publication.

Healthcare professional interested in responding to this piece or submitting their own work to MD Magazine® can do so

Articles

David Ludvigson and Nam Tran, PhD, write about the need for rapid triage testing as a method of improving outcomes for patients with acute kidney injury. 