As dialysis centers prepare for the the need—either current or increasingly likely—for inpatient units to work at surge capacity to manage patients during the COVID-19 pandemic, it’s becoming clear that constraints on both personnel and resource supplies may make it impossible to successfully dialyze all patients using standard procedures. In such a scenario, institutions may aim to temporarily adjust their standard of care to provide sufficient treatments to as many patients as possible.
A paper in the Clinical Journal of the American Society of Nephrology provides guidance about different strategies and contingency plans that might be employed. Jamie P. Dwyer, MD, is a professor of medicine and director of the Nephrology Clinical Trials Center at Vanderbilt University Medical Center in Nashville, TN, and one of the authors of the study (1). Dwyer and colleagues published the paper to provide practical ideas about how inpatient dialysis units might best maximize their available staff and resources.
Although the incidence and pathophysiology are unclear, acute kidney injury occurs in a significant minority of COVID-19 patients, and many critically ill patients have required renal replacement therapies. In some areas of the country, kidney failure patients with suspected or confirmed COVID-19 infections on maintenance dialysis are being triaged to hospital centers, potentially further increasing the strain on inpatient dialysis units.
Conserving dialysis supplies and equipment
Centers should plan for the possibility that dialysis supplies and equipment may need to be rationed. Dwyer suggested that permissive underdialysis may need to be employed in the inpatient unit, shortening dialysis treatment time to three hours in stable and appropriate patients. If needed, kidney failure patients could be shifted from a schedule of three to two hemodialysis sessions weekly. Such strategies would allow for additional patients to be dialyzed over a given period.
To conserve dialysate supplies, dialysate flow rates could be adjusted to a maximum of 600 mL/min. If dialysis fluids for continuous renal replacement therapy (CRRT) from commercial providers are in short supply, hospital pharmacies could compile replacement fluids via standard recipes. If peritoneal dialysis fluids are available, these may also be utilized as potential replacement fluids. Additionally, fluids and other resources might be available from outpatient dialysis clinics, where needs may be less acute.
A component of resource conservation is reducing the number of patients who might need dialysis. Juan Carlos Q. Velez, MD, is chair of the department of nephrology at Ochsner Medical Center in New Orleans, LA, an epicenter of the outbreak.
“We are trying to be very judicious about who could be managed medically and not just put everyone with acute kidney injury on dialysis,” Velez said. “However, when patients become critically ill, dialysis is often an essential component of life support. Fortunately, we have been able to adapt and expand our resources to continue providing optimal care during these challenging times.”
Rigorous control of electrolytes and fluid intake in hospitalized patients with kidney failure can help delay the need for dialysis. In some patients with residual kidney function, diuretics may be used to treat volume overload instead of dialysis, and oral alkali replacement and diuretics might be used to manage metabolic acidosis. Novel drugs are now available that can also remove potassium from the body, potentially obviating the need for dialysis.
To help facilitate these strategies, Dwyer strongly recommended early engagement of the hospital system’s pharmacy and therapeutics committee. “It is key to make sure that your hospital’s pharmacy team knows that these drugs need to be emergently added to the formulary,” he said.
Rethinking and reorganizing dialysis modality
It is also crucial to think about how to best use the available machines for hemodialysis and CRRT if these resources become constrained. “It’s important to get a good assessment of the types of devices you have and think about how to use them broadly,” said Dwyer.
For example, some centers have dedicated machines that can perform isolated ultrafiltration. Such machines might be designated for patients who need fluid removal but could delay standard dialysis, freeing up the use of full-size dialysis machines. Dwyer suggested that centers may want to look locally to rent, borrow, or buy such machines if available. However, ordered machines may not be available immediately given demand. Additionally, when new machines arrive, it may take several days before they can be safely used.
“If there are unused dialysis machines sitting in an outpatient unit or in a hospital without a lot of COVID patients and a low census, we need to find clever ways to move those over emergently and worry about some of the regulatory concerns and financial constraints later,” Dwyer said.
If CRRT machines are limited, standard intermittent hemodialysis machines could be used to perform sustained, low-efficiency dialysis (SLED) using lower dialysate and blood-flow rates to meet the needs of critically ill patients. (SLED is also known as PIRRT, prolonged intermittent renal replacement therapy). Similarly, to ensure that more people receive treatment with existing CRRT machines, one could use CRRT machines running at higher than normally prescribed clearances for 10 to 12 hours.
This method is already being employed selectively at New York University (NYU) in New York City, a current outbreak hotspot, although not all patients can tolerate it, said David M. Charytan, MD, Normal S. Wikler Associate Professor of Medicine and chief of the division of nephrology at NYU.
“For those who can, it relieves nursing issues a bit, because for one patient you have one-to-one nursing for 10 to 12 hours instead of 24,” he said. “And you can use one machine to treat two people in the same amount of time you used to treat one.”
Dwyer and colleagues noted that critically ill patients already on extracorporeal membrane oxygenation (ECMO) can receive isolated ultrafiltration in a non-traditional way if CRRT machines are in short supply, by adding an in-line hemofilter into the ECMO circuit. Replacement fluid could potentially be added as well, if needed. Although this method would require close monitoring of intake and output volumes and would be more inaccurate than commercially available CRRT, it is an option worth considering.
Urgent start peritoneal dialysis (PD) for acute kidney insufficiency could also be considered to decrease resource drain on inpatient units. However, Dwyer noted that some patients may be too sick to go to the operating room to have surgery. Some centers may have surgeons or interventional radiologists who are able to place a PD catheter at the bedside. Theoretically, nephrologists may be able to perform such placement if absolutely needed, although younger nephrologists currently lack the training to do so. Dwyer said, “I think we need to think broadly about what areas of expertise our colleagues have and remember that acute PD was a thing 30 years ago.”
Charytan noted that many centers in New York are preparing to implement urgent start PD. “If our need for renal replacement therapy is double or triple what we normally have to provide, it is hard to see another way,” he said. “This can probably help provide adequate if not ideal therapy to many more patients, because the requirement of nurses and the requirements of equipment are less.” However, not all centers will have the expertise to implement this efficiently.
A more extreme consideration is continuous arteriovenous hemofiltration, which might be an option for critically ill patients not on ECMO if CRRT machines are lacking. Although many centers lack contemporary expertise with such a setup, some places will have older personnel who may be able to employ the technique if absolutely necessary.
Managing human resources
Human resources may be limited as well. COVID-19 infections may decrease the number of skilled personnel available to dialyze patients. Charytan emphasized the critical importance of skilled nursing personnel to run both ICU and dialysis floors. For example, nurses new to an expanded ICU floor may lack the expertise to perform CRRT. At Ochsner, Velez and colleagues implemented urgent online CRRT training for nurses to help fill some of these needs. Charytan agreed that it may be helpful to think through who might capably run dialysis and assess what training and expert guidance they might need.
Dwyer suggested it may be possible to urgently credential outpatient nurses to work in the inpatient setting, although this would require flexibility from local organizations and potentially advocacy on the part of nephrologists.
Because they spend more time with patients, nurses are at higher risk of infection than physicians, and Charytan emphasized the importance of taking measures to try to keep the nursing staff healthy. Dividing patients and nurses into cohorts and encouraging social distancing at work might help reduce disease spread. To decrease exposure of dialysis nurses, it might be helpful to preferentially use CRRT for patients in the ICU infected with COVID-19. Through telemonitoring, it might be possible to reduce the amount of time nurses need to spend inside patient rooms.
With the use of extension tubing, the CRRT machine could be run outside the patient’s room, decreasing nurse exposure. However, Velez noted that this should be weighed thoughtfully, as COVID-19 patients seem to have a higher risk of hypercoagulability, which could be exacerbated by such tubing. Such a measure might make the most sense in institutions that have machines that require more frequent interventions by nurses.
Now is the time to take stock of physical and human resources, Dywer said. “We don’t have much time to prepare, which is why getting prepared now, as soon as possible, is mandatory.”
Added Velez, “This is a time to be bold and creative and innovative but at the same time be very vigilant for patients, because when you are exploring new territories, the risk for human error increases. We are doing the best we can for our patients, but we have to make sure we don’t cause harm and we keep our workforce safe.”
Reference
Burgner A, Ikizler T, Dwyer J. COVID-19 and the inpatient dialysis unit: managing resources during contingency planning pre-crisis Clin J Am Soc Nephrol 2020. DOI: https://doi.org/10.2215/CJN.03750320
