When the COVID-19 crisis began, much of the media attention focused on the effects of the infection on the respiratory system and the critical need for ventilators to treat patients in respiratory distress.
But clinicians on the frontlines treating critically ill patients soon learned that COVID-19, or the body’s response to it, could also injure other organ systems. The virus may primarily attack the lungs, but an unexpected complication — kidney failure — became another major obstacle for doctors in the ICU. It also created a new and perhaps overlooked medical supply crisis — an acute shortage of dialysis resources.
Dr. Susana Bejar, an internal medicine specialist at Columbia University’s Irving Medical Center, one of the hospitals in the New York area hit hard by the virus, spoke to Yahoo News and described how the number of patients who experienced renal problems took many providers by surprise.
“We were expecting that people would have respiratory failure and need the ventilators, so we very intensively moved to get a lot more of them, but what we weren’t expecting is the amount of severe kidney failure,” she said.
It is not yet known whether the kidneys are a direct target of the virus, if the issues are secondary to other processes such as blood clots forming in the small blood vessels of the kidneys, or some combination of both. Researchers have found evidence that the virus may have an affinity for certain structures on both lung and kidney cells called ACE-2 receptors.
Dr. Alan Kliger, a nephrologist at Yale University School of Medicine and co-chairman of the COVID-19 response team for the American Society of Nephrology, told Yahoo News that the number of patients with kidney failure due to the virus is unprecedented.
“I’ve been a kidney doctor since 1975, so I’ve been in this business for a long time. I’ve never seen anything like this. … We knew early on that there was a problem with the kidneys from the infection, but the real surprise was when the pandemic hit in the United States, we found that between 20 and 40 percent of patients who were in intensive care units with this infection — their kidneys failed.”
Patients in kidney failure require dialysis, in which a machine does the job of the kidneys in filtering and cleaning a patient’s blood of waste products.
Dialysis treatments are common in people who suffer from chronic kidney disease (CKD), which according to the National Kidney Foundation affects an estimated 37 million U.S adults. Those whose kidneys become damaged over time can experience kidney failure, for which dialysis or a transplant would then be needed to stay alive.
Approximately 500,000 CKD patients in the U.S. receive dialysis treatments, either at home or in centers. Kliger said this group of patients is at higher risk for developing serious complications from COVID-19, but people with no preexisting kidney issues have also been affected. “We’ve learned that acute kidney failure is a major complication for people who otherwise had been healthy but are hospitalized,” he said.
The type of kidney affliction seen in COVID-19 patients is called acute kidney injury (AKI). Unlike chronic kidney disease, which happens over time, AKI is a sudden loss of kidney function resulting from damage to the cells of the kidney’s filtering system. Many times, kidney function can recover after AKI, but it can also result in permanent dysfunction. Doctors don’t yet have enough information to know if there are long-lasting effects from kidney failure secondary to COVID-19.
“People are needing dialysis, and not just any dialysis, but a special kind of dialysis that can only be done in intensive care units … because patients are too unstable to tolerate the fluid shifts of regular dialysis,” said Columbia’s Bejar.
When she spoke to Yahoo News two weeks ago, cases in the New York area were peaking. Her hospital’s dialysis resources were stretched to the breaking point.
“Right now nephrologists are experimenting with different ways to have patients using the same dialysis machines,” Bejar said. “We are running out of dialysis medications, the dialysis nurses, and these are the machines that are keeping patients alive."
Most dialysis protocols for patients with chronic renal disease consist of three- to four-hour sessions a few times a week in an outpatient setting. But the preferred treatment for ICU patients with unstable blood pressure is different. It consists of a slow and gentle dialysis called renal replacement therapy (CRRT) that is usually administered over 24 hours, allowing the patient’s blood pressure to remain stable.
Many major hospital groups in New York City and areas that experienced a surge in the demand for ventilators similarly struggled to meet with the demand for CRRT machines.
“You can’t separate the two because most patients that require dialysis are also on ventilators,” Yale’s Kliger said.
Dr. Steven Fishbane, chief of nephrology for Northwell Health, a system of 23 hospitals in New York, also told Yahoo News that patients on ventilators almost always need dialysis as well. “It’s interesting because we’ve really just learned this recently, that it’s a pretty sharp cutoff.”
Many of the hospitals in surge areas with high ICU volume have experienced a shortage of dialysis supplies, particularly the fluid needed to run the CRRT dialysis machines.
Doctors have had to improvise and come up with new ways to provide treatment for patients whose lives depend on it. Some have turned to peritoneal dialysis, which uses the membranes of the peritoneum, the lining of the abdominal cavity, as a filter, rather than running blood through an external machine. But it is not ideal for ICU patients. Others have implemented machine-sharing protocols for patients whose conditions permit it.
Fishbane says Northwell Health hospitals were fortunate enough to prepare in advance and have had enough supplies. “In February, as we saw what was happening in China, we modeled out what it looked like in terms of a best-case, medium-case and worst-case scenario, and we did a lot of purchasing of dialysis equipment and CRRT equipment.”
Outpatient dialysis facilities have also reported challenges, including separating COVID-19 positive and negative patients and protecting their own workers.
ICUs are also affected by a shortage of nurses and dialysis technicians to run the CRRT machines. “The bigger issue for us was nursing for the intensive care units. Nurses were now taking care of four patients per nurse. That's really spreading them and causing tremendous, tremendous stress on the nurses running CRRT treatments,” Fishbane said.
Government agencies and private industry are stepping up efforts to keep hospitals supplied. Fresenius, the nation’s leading provider of kidney care products and services, recently announced the formation of a National Intensive Renal Care Reserve to provide additional dialysis machines. The company has created a pool of 150 pieces of equipment that can be immediately deployed to the areas most in need. A Federal Emergency Management Agency spokesperson told Yahoo News that the Department of Health and Human Services is working with states and localities to help address shortages: “FEMA regional staff and the HHS Strategic National Stockpile recently provided assistance to New York state through the deployment of 50 portable dialysis machines that will help expand dialysis surge capacity in New York City and surrounding areas.”
Although hospitalizations in surge areas like New York have decreased recently, there are still many critically ill patients in the ICUs needing dialysis. According to projections from the University of Washington’s Institute for Health Metrics and Evaluation in Seattle (IHME), peak demand for hospital resources occurred at the national level last Friday. But this varies by state, and some are expected to peak later on, which could mean those places could possibly face similar challenges.
“We are more prepared than we were two weeks ago, but honestly, we’re continuing to learn the lessons,” Kliger said, “and try to share those messages so that other places, when faced with the same issues, will be perhaps better prepared.”