HEALTH-SYSTEM EDITION
TECHNOLOGY

N.Y. study evaluating computerized heparin alerts

The department of pharmacy at New York Presbyterian Hospital (NYPH) in Manhattan has begun a study to evaluate a computerized order entry system for intravenous unfractionated heparin.

The study is comparing the computerized system to a printed order form that includes a standard weight-based algorithm for initial and maintenance dosages, said Anne Marie Greco, Pharm.D., clinical coordinator-Adult Critical Care at NYPH. The study's goal is to determine if the use of computerized decision support tools improves adherence to the heparin-dosing protocol.

The use of unfractionated heparin as an anticoagulant has decreased due to the advent of low-molecular-weight heparin, Greco noted. Low-molecular-weight heparin does not require the therapeutic monitoring that unfractionated heparin does. However, LMWH is not the drug of choice in all situations, she said.

"The question is, Is there a better compliance rate with the algorithm using a computerized system?" she said. "The intent is to get the physician to react as quickly as possible so the patient is anticoagulated as quickly as possible."

In one arm of the study, physicians or other prescribers, such as nurse-practitioners, use a printed form that includes an algorithm or protocol for appropriate heparin administration rates based on the patient's dry weight and activated partial thromboplastin time (aPTT). The prescriber then chooses a dosage from that for the patient, she said. However, she noted, the prescriber must look up the patient's aPTT and other lab results before using the algorithm and filling out the form. The completed form is then faxed to the hospital pharmacy.

The computerized prescriber order entry system being evaluated in the study contains the same algorithm for using unfractionated heparin as on the printed form, Greco said. A CPOE system is in place in several areas of New York Presbyterian, and the algorithm is programmed within that system. The system is designed to remind physicians or other prescribers about the algorithm for using heparin, provide dose recommendations based on patient data, and issue reminders for adjusting doses when new lab results are available.

The system asks the physician if he or she wants to use the heparin algorithm and informs the physician, via an electronic alert, if the algorithm does not apply. The computer pulls up the dry weight of the patient along with the proper initial and maintenance dosing from the algorithm, then determines the proper bolus and infusion rate of unfractionated heparin for that patient. At that point, the physician uses the system to order the heparin from the pharmacy and to order any needed lab work for the patient, she explained.

When the patient's aPPT results come back from the lab, the computer automatically brings up an alert that the result is available whenever anyone opens the patient's computerized chart for any reason, Greco said. This puts the patient's coagulation status on immediate view. The system will also suggest changes in heparin dosage or administration rate based on the aPPT values.

"If you look at the original work done on the weight-based algorithm, many times you overshoot anticoagulation for the patient," Greco said. The CPOE system can catch that situation quickly, she added.

Generally, it is more dangerous for the patient to be undercoagulated than overcoagulated, Greco noted. "There is a benefit for the patient to ensure that he or she is adequately anticoagulated and then pull back if the aPPT is too high." The incidence of bleeding is no different using the algorithm than not using it, she added.

The New York Presbyterian study, which is funded by a National Patient Safety Foundation Research award, is about one-third completed and is expected to be wrapped up by the end of 2003. Greco said preliminary results are not yet available. She added that a computerized algorithm system for determining the correct dosage of unfractionated heparin has been studied in community hospitals. It has worked very well in smaller hospitals with nurses following the algorithm, she said.

Greco's colleagues in the study are Michael I. Oppenheim, M.D.; Ferdinand Velasco, M.D.; Rudina Odeh-Ramadan, Pharm.D.; and Josephine Sollano, MPH.

Valerie DeBenedette

The author is a healthcare journalist based in New York.

Valerie DeBenedette. N.Y. study evaluating computerized heparin alerts.

Drug Topics

2003;6:HSE44.