They found an 84% decrease in the rate of deep venous thrombosis (DVT) – from 1.9% to 0.3% – while the incidence of pulmonary embolism (PE) dropped 55%, from 1.1% to 0.5% (p<0.01 for both).
Senior author Dr. David McAneny spoke with Reuters Health by phone and said, “We were gratified by the improved outcomes after the implementation of our programs.”
The before-and-after study was prompted by the authors’ recognition that their hospital had a high rate of VTE compared to other institutions participating in the National Surgical Quality Improvement Program (NSQIP).
Dr. Peter K. Henke, a professor of surgery and Associate Chair of Research at the University of Michigan, has studied VTE extensively. He said the paper is a “solid contribution to the literature, particularly addressing a high VTE rate at their institution and approaching this in a systematic manner with marked improvement.”
Prior to developing the VTE prevention strategy, no formal prophylaxis guidelines were in place.
The team adopted the Caprini VTE risk stratification method for all general and vascular surgery patients and developed standardized prophylaxis regimens-including drugs, mechanical devices, and ambulation orders-linked to the risk scores.
“The inter-rater reliability of Caprini scoring has been good,” said Dr. McAneny. “In addition to surgery residents, our physician assistants are an important part of maintaining consistent practices.”
Their electronic medical record was modified to require completion of both the risk score and the orders for prophylaxis.
Heparin and mechanical compression were optional for the lowest-risk patients, who were walked frequently. Low-risk patients were treated with either heparin (low dose unfractionated or low molecular weight) or compression boots, and those scored as moderate-risk got both heparin and boots.
High- and highest-risk patients were to receive extended prophylaxis of boots and heparin for seven to 10 days or 30 days, respectively, continuing if necessary after hospital discharge.
At the University of Michigan, “We use the Caprini scoring system and have mandatory risk assessment,” said Dr. Henke. His group typically administers 30-day prophylaxis only for oncology patients and those with inflammatory bowel disease.
The Boston paper, published online in the Journal of the American College of Surgeons, said the prophylaxis order mandate could be overridden by a physician, but the reason had to be documented in an automatic drop-down menu.
After the prophylaxis program began, recommended prophylaxis in the 749 low- and moderate risk-patients was given 100% of the time. Of the 99 high-risk patients, 89% received appropriate prophylaxis as did 10 (77%) of the 13 patients in the highest risk group. All protocol deviations were documented in the electronic record.
Dr. Henke, who was not an author of the study, wondered about patients who received prophylaxis but did not benefit. He said, “This is often a neglected part of aggressive VTE prophylaxis. Anticoagulants do have bleeding risks, and at the very least, a significant monetary cost.”
Dr. McAneny’s group is now analyzing failures of the protocol. He said, “We are investigating patients who developed VTEs despite the protocol, questioning if those events were a function of improper scoring, withholding recommended prophylaxis, or some other reason.”
Before the protocol was adopted, audits of nursing practice showed that only 19.6% of 250 patients were out of bed at the time of the visit vs. 69.1% after the intervention (p<0.001).
Other NSQIP hospitals of over 500 beds during the years studied had annual rates of 0.8% for DVT and 0.4% for PE.
Using a risk-adjusted NSQIP data for the authors’ hospital, the ratio of observed to expected VTE was 3.41 prior to instituting the program, and steadily decreased to an odds ratio of 0.94 (p<0.05).
“It will be difficult to get the rate of VTE to zero because the risks of bleeding from anticoagulation sometimes outweigh the risks of VTE so that prophylaxis cannot be administered,” said Dr. McAneny also noting that certain patients will develop VTEs despite appropriate prophylaxis.
He mentioned several important factors in the success of their program such as its standardization, buy-in by the surgeons-they are all competitive people and none wants to be on the wrong side of the outcomes curve, a user-friendly system with check-box format, mandated VTE hazard scoring and prophylaxis selection or declination, electronic reminders, and regular monitoring and feedback of data.
J Am Coll Surg 2014.