Critical Care and Nephrology: A Match Made in Heaven or a Mere Crush?

Literature shows that over half of the patients admitted to the intensive care unit (ICU) will eventually develop some degree of acute kidney injury (AKI). The development AKI imparts significant repercussions to both the acute and long term management of patients with critical illness. AKI is one of the most common acute organ dysfunctions seen in critically ill patients and is associated with higher mortality, morbidity, and healthcare expenditure. As such, it is well recognized that meticulous care is paramount in patients with AKI in the ICU.  There is also an often unrecognized hand-in-glove relationship between AKI and development of fluid overload, so much so that that de-resuscitation is now considered an important part of the overall care of those critically ill.

AKI is just a fraction of kidney-related issues that affect patients with critical illness. Electrolyte disorders (e. g. hyponatremia, hypokalemia, and hypomagnesemia), acid-base disorders (both acidosis and alkalosis) and the subtle but equally challenging phenomenon of “fluid creep” are just some of the other important issues in the realm of nephrology that directly impact the management strategies and outcomes of patients in the ICU. Therefore, it is obvious that a close working relationship between nephrologists and intensivists would play a vital role in caring for those critically ill.

It is well known that medicine is a team sport and it takes a village to take care of the critically ill. As intensivists, we collaborate extensively with surgeons, nephrologists, infectious disease specialists, cardiologists, nurses, advanced practice providers, pharmacists, nutritionists, and therapists on a daily basis to provide optimal care for our patients. However, as patients can decompensate anytime and with intensivists at the front lines, it becomes crucial for them to have a working knowledge of various subspecialties to provide immediate lifesaving therapies in real-time at the bedside. As AKI, electrolyte derangements, and acid-base disorders can often lead to life-threatening situations requiring urgent intervention, it seems prudent that an intensivist armed with the working knowledge of these disorders would be much more comfortable in appropriately managing them in a timely fashion. Thus, these situations open the door to a specialist who is dual-trained in nephrology and critical care.

Although the exact numbers of nephrology-critical care trained physicians and their career trajectories is unclear, there is a palpable and rising interest in this combination. My critical care fellowship class at the Mayo Clinic had four nephrologists and my current practice has three dually trained physicians. Our Division Chief, Dr. Paul McCarthy decided to undergo further training in nephrology after over a decade of practice as an intensivist. In his own words,

“While in my critical care training I began attending the annual CRRT meeting in San Diego, which has continued to expand my interest in nephrology. During my critical care practice, I saw firsthand the importance of acid-base, electrolytes and fluid balance. With the importance of these issues in taking care of patients in the intensive care unit, when the opportunity to formally receive additional training occurred, I felt it was the right thing to do. My nephrology training has made me a better intensivist.”

The data is sparse, but as an intensivist who training in both nephrology and critical care, there are many ways to carve one’s career path. The interest and job market in this specialty are still evolving, but several different pathways are starting to emerge:

1. One can practice primarily as an intensivist or a nephrologist while using the knowledge gained in both specialties
2. Some practices allow physicians to split time between practicing both as an intensivist and an acute care nephrologist.
3. Models incorporating nephrology/dialysis clinics are uncommon in the present time, but exist.

In our group, we practice primarily as intensivists in a shift-based model (days or nights) and provide acute care nephrology expertise for patients in our unit. We have a strong collaboration with our nephrology division and we involve them in a timely fashion before the patient is ready for transfer to the regular floor.  In addition to managing mechanical ventilators and other mechanical circulatory support devices (i.e balloon pumps, ventricular assist devices, extracorporeal membrane oxygenation machines) we also provide continuous renal replacement therapy and plasmapheresis for our patients as needed. In addition, we utilize point of care ultrasound (POCUS) on a daily basis as one of the tools to provide the best possible care for our patients.

If you are interested in delving further into the amazing subspecialty combination of nephrology-critical care, I highly recommend attending the annual AKI & CRRT Meeting and the Critical Care Nephrology programs at the American Society of Nephrology Meeting. Here are some good references for introduction to the topic. The list of 1-2 year critical care medicine fellowships where one can apply before or after nephrology fellowship is available at ERAS.

As such, this seems to be just the beginning of nephrology-critical care and the possibilities are endless. I have been fortunate to have colleagues and mentors who have followed their passions through different pathways and have never shared regretting their decision to train in either of the sub-specialties. I think most would agree that training in both specialites widened their world-view and refined their approach to helping those that need us the most – our patients

Ankit Sakhuja, MBBS FACP FASN
NSMC Intern, Class of 2019