6 minute read
Modern Technology Brings Life-saving Treatments to Smaller Babies
Written by Rick Stoff
If a newborn requires hemodialysis to treat kidney failure, a few ounces of its blood must temporarily leave its body while it is pumped through a machine that cleanses it. An infant weighing 5.5 pounds, however, only has eight ounces of blood. Because of their small fluid volumes, children weighing less than 20 pounds were unable to undergo continuous renal replacement therapy (CRRT), even at SSM Health Cardinal Glennon Children’s Hospital where nephrologists have long been pioneers in treating neonatal kidney disease.
That changed this year when SSM Health Cardinal Glennon became one of the first pediatric hospitals in the country to acquire CARPEDIEM™ (Cardio-Renal Pediatric Dialysis Emergency Machine), a groundbreaking machine that provides continuous dialysis to small babies in the neonatal intensive care unit (NICU).
“Our use of intermittent hemodialysis for babies has been unique for this region. Intermittent hemodialysis on babies is very challenging and higher risk than this new technique, which is more continuous, slower and more gentle,” says Craig Belsha, MD, professor of pediatrics in the Division of Nephrology at Saint Louis University School of Medicine.
Invented by Italian nephrologists, CARPEDIEM™ is the first renal replacement therapy machine designed for children weighing 5.5 to 22 pounds. The purchase was underwritten by the SSM Health Cardinal Glennon Children’s Foundation.
“We had been using equipment designed for adults, with some special tubing and filters, in the pediatric intensive care unit. We would use that hemodialysis machine on children under 20 pounds when there were no other options, but it had limitations and drawbacks. The new machine gives us a means of doing continuous renal replacement therapy in newborns,” says Dr. Belsha.
Each infant hemodialysis procedure on the previous machine required exposure to foreign blood products to prime the pumping system. CARPEDIEM™ can be primed with about one ounce of blood, half of the volume used by conventional equipment. “We didn’t have other equipment that takes such a small volume of blood outside the body at a given moment,” Dr. Belsha says.
Kidney Dialysis in Infants
“Some children are born with very small kidneys or without kidneys,” Dr. Belsha says. “They may have a urinary tract blockage or a disease that can lead to kidney failure. Some babies aren’t born with a kidney problem but are sick with sepsis or low blood flow. A heart problem or other underlying health issue can lead to renal failure and fluid overload.”
“Through urine production, the kidneys control fluid management, control salts and excrete waste products,” says Anne Beck, MD, a pediatric nephrologist and professor of pediatrics at Saint Louis University School of Medicine.
“An acute or chronic issue with the kidneys can be life threatening.” When kidney function is lacking or limited, dialysis supports the body until the kidneys recover or the child grows large enough to undergo a transplant. “Some centers haven’t done chronic hemodialysis in newborns. We have been — we’ve had 10 patients over the past 10 years who were in the neonatal intensive care unit and needed hemodialysis to grow and go to transplant,” Dr. Belsha says. “It may take them a couple of years to grow enough.”
Dialysis may be provided in two ways. For peritoneal dialysis, a catheter is surgically placed through the skin of the belly to admit a cleansing fluid. The peritoneum lining of the abdomen filters wastes from the blood, and then the fluid and wastes are withdrawn. “For some babies, that is not the best way to do dialysis. They have had abdominal surgery or infections or there is fluid leakage around the catheter because the skin of newborns is so thin,” Dr. Belsha explains.
A hemodialysis machine pumps the patient’s blood through a filter and returns it in a continuous loop. “The CARPEDIEM™ will need fewer blood products so the children will have less chance of exposure to antigens,” Dr. Beck says. “If the child ultimately needs a kidney transplant, there will be a reduced risk of antibodies, and it will be easier to find a new kidney match.” Children must grow to a minimum of 22 pounds to receive a kidney transplant.
CARPEDIEM™ was approved by the U.S. Food and Drug Administration (FDA) in 2020. It provides CRRT for up to 22 hours a day. FDA approval was based on data from European and US registries for patients under 22 pounds. Survival following CARPEDIEM™ CRRT was 97%, double the rate for machines designed for adults that have been adapted for pediatric patients.
“The system is far more accurate,” Dr. Belsha adds. “We run dialysis fluid to help clean the blood at a rate of about 300 milliliters (10 ounces) an hour. The scales can recognize if there is about a teaspoon of difference.”
Nursing Skills
“It takes a high skill set to manage these kids,” Dr. Beck says. Training was presented last summer to 15 NICU nurses who volunteered to become CARPEDIEM™ providers. “We had one week with the vendors of the machine and another week with nurses from a hospital that has a large CRRT program,” says Krista Nelson, BSN, RNC, a NICU manager. “They had to learn everything about running the pump, priming it, maintaining the lines and catheters, and following all of the patient’s vital signs to make sure it is working adequately.”
“The nurses will be experts on that piece of equipment. It will be continuously monitored while the patient is on the pump,” says NICU Manager Beth Lamkin, MSN, RN. “Our team is really excited about this opportunity.”
Dr. Beck explains, “The patient volume will be small but, for those patients, the impact will be dramatic.
