By Steven Clark
The “canary in the coal mine” analogy is how critical care physicians tend to view Acute Kidney Injury (AKI) within their ICU population. Like the caged canaries that miners brought with them down into the mines to determine the presence of carbon monoxide – by succumbing to the poisonous gas the birds would warn miners that it was time to flee – AKI can be an early warning sign of danger.
“We always have the kidney panel on and if anything is awry in the body the kidneys will start screaming,” says Dr. Jamil Ibrahim, a critical care physician and nephrologist at SBH. “You can come in, for example, with pancreatitis, which has nothing to do with the kidneys, and you can end up with kidney failure, or have a toe infection that brings on renal failure. The kidney is a very sensitive organ.”
The causes for AKI are often multifactorial. Severe infection, sepsis, urinary obstruction, pelvic masses and trauma, as well as nephritis inflammatory diseases, are all common causes. And, with the advent of COVID-19, the numbers of patients in kidney distress in ICUs across the country have dramatically increased. According to Dr. Bessy Flores, a nephrologist at SBH, during the pandemic the kidney is the most likely organ affected after the lungs. The high death toll last spring among hemodialysis patients, in fact, became the catalyst for a treatment upgrade at SBH.
“During the COVID-19 surge it became apparent that our overall ability to deal with the large number of patients needing hemodialysis, and the subset who might benefit from Continuous Renal Replacement Therapy (CRRT) was deficient and this program required an upgrade,” says Dr. Ed Telzak, chair of the Department of Medicine at SBH. “CRRT was long overdue and the surge made it more apparent.”
Yet, as Dr. Telzak acknowledges, the learning curve is steep with CRRT, and intensive care demanded, as there needs to be a one-to-one ratio between nurse and patient during the continuous treatment. This is why CRRT tends not to be offered in community hospitals.
This has since resulted in the purchase of three CRRT machines for the ICU. Nurses have been training on the technology with the intention to begin offering it this spring, says Dr. Ibrahim, “to our most critically ill patients with the most dire needs.”
With AKI, it’s often not just a kidney issue, he explains, but a systemic issue. “We never work alone as nephrologists, but with other subspecialists. We need to treat the entire patient and have to balance other systems.”
He and Dr. Flores both view CRRT as a game changer in taking care of extremely ill, unstable patients. This is a type of blood purification therapy that passes the patient’s blood through a special filter that removes fluid and uremic toxins, returning clean blood to the body. Unlike hemodialysis, which is generally given on an outpatient basis for three to four hours a day, three days a week, CRRT runs continuously 24 hours a day. It is a far gentler process for ICU patients whose bodies can’t tolerate regular dialysis because of the pressure put on the heart and other organs. While most patients requiring CRRT do not suffer from chronic kidney disease, some hemodialysis patients will cross over in their need for the gentler treatment.
Most seriously ill COVID-19 patients who require CRRT are simultaneously on ventilators. Dr. Flores, who at the time COVID-19 hit New York City hospitals was training as a nephrology fellow at Northwell in Queens and Long Island (Dr. Ibrahim was two years ahead of her in the program), saw the damage the virus did there. “With CRRT, some patients were able to be salvaged and did recover. It is a pretty objective decision on when to remove patients from CRRT or put them back on. If they improve, we can transition them to hemodialysis and then, hopefully, take them off dialysis completely.”
In the case of a patient coming in with septic shock with very low blood pressure and very high potassium levels, doctors would look at improvements in these conditions and the production of more urine to slowly withdraw them from CRRT. “It gives critically ill patients time to resolve their issues,” says Dr. Ibrahim.
One patient she remembers, a female physician in her 50s, who had previously been healthy, had a severe case of COVID-19 with renal failure. Like most COVID-19 patients, both the condition of her lungs and kidneys deteriorated with 48 hours of hospitalization. She stayed on CRRT for three weeks, was eventually taken off the ventilator, and left the hospital after three or four months.
An article in the New England Journal of Medicine demonstrated that CRRT provides more gentle solute (waste) and fluid removal than standard dialysis. This is crucial, according to the article, because the mortality rate for critically ill patients with acute kidney failure who need dialysis is reportedly higher than 50 percent.
“It’s a phenomenal therapy for Covid patients,” says Dr. Ibrahim. “It should be in the arsenal of every physician to sway the balance. I think this will really help.”