Transplant Medicine
Innovations in process improves medication safety
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Transplant Medicine Two years after introducing statistical process control, the benefits are clear. When John Bucuvalas, MD, began using SPC, only about 35 percent of the liver transplant program's 200 patients had blood medication levels within target range. Today, 70 percent of the patients are within target range. |
Looking at 6-year-old Julian Thanthavongsa now, you'd never guess how desperately ill he was at birth. He had two life-threatening liver diseases — a large, cancerous tumor and biliary atresia, a rare condition in which the bile ducts are blocked, causing bile to be trapped in the liver.
He was started on chemotherapy when he was just 2 days old, spent his first seven months in newborn intensive care at Akron Children's Hospital, and underwent a liver transplant at Cincinnati Children's Hospital Medical Center when he was 7 months old.
"People say he's a survivor," remarks Julian's brother Jamie, age 8. Indeed, he is.
Daily Life After Transplantation
The first years after the transplant were a struggle for Julian and his parents. Back home in Akron, the family coped with a complicated daily regimen that included giving Julian many medications to prevent organ rejection and infections. He had a blood test every week to monitor his liver enzymes and medication levels. The test results were phoned in to gastroenterologist John Bucuvalas, MD, his transplant doctor at Cincinnati Children's, who regularly adjusted the drug dose to get Julian's medications stabilized at the ideal level. The family traveled to Cincinnati every three months for a comprehensive checkup with the transplant team.
"That first two or three years, I thought I would just give up," his mother, Ratsamy, recalls. "But we've been lucky. He's stable now. He gets medicine twice a day. It's so simple."
Improving Outcomes for Transplant Survivors
Julian is part of a growing community: liver transplant survivors. While the number of liver transplants performed annually has remained relatively constant, the number of survivors has increased dramatically, says Dr. Bucuvalas.
Thanks to medications introduced in the 1990s and improved methods of care, the one-year survival rate after liver transplant has increased from less than 50 percent about a decade ago to 90 percent today. Many patients, like Julian, are long-term survivors.
Like all transplant recipients, Julian will spend the rest of his life taking a drug that suppresses his immune system to prevent him from rejecting his transplanted liver. The drug is essential, yet it is also potentially harmful, especially when taken for many years. Side effects can leave patients at increased risk for:
- Infections
- Cancer
- High blood pressure
- Heart disease
- Kidney disease
- Osteoporosis
These risks are greatest in children, since they have a longer potential life span than adult transplant recipients.
Doctors who provide long-term care for liver transplant survivors face a new challenge: How can we maintain the best possible liver function with the least possible risk?
Dr. Bucuvalas and his colleagues at Cincinnati Children's have tackled this challenge in an innovative way that has been called one of the top 10 new ideas in health care delivery by Don Berwick, MD, executive director of the Institute for Healthcare Improvement.
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"Statistical process control changed the way I think. It helps me ask the right questions so I can deliver better care." John Bucuvalas, MD | |
Applying Knowledge From Outside Medicine
The idea for this innovative approach was sparked when Dr. Bucuvalas attended an advanced training program in clinical quality improvement, along with transplant surgeon Frederick Ryckman, MD, and nurse coordinator Brandy Andrew, RN.
There they were introduced to a concept familiar to engineers but foreign to health care professionals: statistical process control (SPC).
SPC uses statistical methods and control charts to analyze and improve processes. Automobile manufacturers, NASA engineers and others involved in making high quality, complex products use SPC to achieve consistently high performance for complicated processes. Could this science be applied successfully to health care delivery systems, too?
Imagine if statistical process control could help transplant physicians do a better job of keeping their patients' immunosuppression medications at optimal levels. When they returned from the conference, Dr. Bucuvalas was determined to test whether SPC would improve transplant medication safety.
Testing the Idea
The basic concepts of statistical process control are simple. SPC starts with the assumption that there's variation in every process. Some variations are the result of "common causes." Their effects are consistent over time. This type of variation is predictable and acceptable. Reacting to these changes is like responding to a false alarm. Tampering with common causes only produces more variation.
The SPC approach uses statistical analysis to define acceptable limits and plots data on a control chart to monitor performance over time. The system makes it possible to distinguish between variation that is within the target range and variation that needs to be addressed to keep the process in control.
When Dr. Bucuvalas began applying these principles to his patients, he found he was able to make better decisions about when to adjust their medication dose.
"Maintaining the optimal drug level is very important and also very complex," he says. "We have a narrow therapeutic window and many variables to account for." The drug level in the blood is affected by many things. When the blood was drawn, how many hours had passed since the patient took the last dose? Was the medicine fresh or from the bottom of the bottle? Did the patient take the medicine as prescribed? Did the patient have an infection? The list of variables goes on and on.
"If I see a blood test result showing a change in drug levels," Dr. Bucuvalas says, "I have to decide, do I change the dose or not? Now I have a platform upon which to decide, and I can have more confidence that my decision is right."
Without SPC as an analytic tool, Dr. Bucuvalas acknowledges, he and his colleagues had a tendency to look at individual test results and try to fine-tune the dose every time they saw a variation. If the level was low, the doctor would increase the dose a little. The next test might show the level was up, so the doctor would change the dose again, creating a pattern of ups and downs.
Now liver transplant physicians at Cincinnati Children's develop a customized target range for each patient and follow the blood test results on a chart that gives a clear picture of the results over time. If several consecutive tests show results that are out of target range, the doctors ask some basic questions:
- Is the target range correct for this patient?
- Is there excessive variation?
- If so, is there a special cause that would account for the variation?
"We don't necessarily change the dose if we see variation," Dr. Bucuvalas says. "We look for the root cause before making a decision. Statistical process control changed the way I think. It helps me ask the right questions so I can deliver better care."
For Julian and other liver transplant survivors at Cincinnati Children's, this innovation in medication management means safer care and a greater promise of a healthy future.
Dr. Bucuvalas is excited at the prospect of applying this approach to benefit patients with a wide range of chronic conditions requiring long-term medication, such as:
- Diabetes
- Seizure disorders
- Asthma
- High blood pressure
- Heart disease
