Post-surgical and bedridden patients are at risk for developing deep vein thrombosis (DVT). This condition occurs when a blood clot forms in a deep vein, especially in the leg. Other risk factors include older age, obesity, smoking, personal or family history, and long operations. DVT can lead to debilitating swelling and chronic pain of the affected limb. Pulmonary emboli, blood clots that travel to the lungs, can cause pulmonary hypertension, and high blood pressure in your lungs’ arteries.
Anticoagulants or blood thinners like Lovenox (Enoxaparin) in prefilled syringes reduce your blood’s clotting ability. Regular injections stop existing clots from growing larger and help prevent new ones from developing. For convenience, shop additional drugs by condition to place one combination order.
DVT Rates Correspond to Lovenox Doses
Missed blood thinner treatments account for much of the deep vein thrombosis that surgery and trauma patients experience, according to a recent study. Scott G. Louis, M.D., and his Oregon Health and Science University colleagues monitored 202 patients in a level 1 trauma center. Of the 59 percent who missed at least one Lovenox dose, 16 percent developed DVT. The DVT rate was 24 percent in patients who missed at least one dose of the low-molecular-weight heparin, compared to just 5 percent among those with uninterrupted therapy.
Withholding treatment was the only independent risk factor aside from older age. It also was the only identified DVT risk factor that doctors could adjust. The rigorous standardized protocol for thromboembolic detection included bilateral whole-leg duplex ultrasonography on a weekly basis for ICU and trauma patients and whenever researchers suspected events in general surgery patients. They concluded that optimizing efforts to minimize interrupted treatment in at-risk patients decreases DVT incidence.
Risks of Skipping Treatments
In Louis’ study of prospectively collected data, the DVT rate didn’t differ between surgical and trauma patients or in those on once- versus twice-daily regimens. About half of patients who didn’t develop DVT missed a dose, but that rate jumped to 88 percent for those who developed the condition.
DVT risk odds rose by the number of skipped Lovenox doses:
- 8.49 percent higher with two to four withheld treatments
- 10.13 for five to eight drug gaps
- 14.73 due to nine to 17 missed doses
Beyond 17 medication interruptions, the relationship ceased to exist, probably because the sample size was small. The researchers didn’t detect any pulmonary emboli.
Reducing Missed Injections
Although clinicians tend to agree that pharmacologic prophylaxis should begin as soon as possible based on each patient’s bleeding risk, the study team noted that doctors decided to withhold Lovenox doses often without assessing the consequences comprehensively. Common reasons for stopping treatment include pending procedures, absence of patients from their hospital rooms, and epidural catheter use.
While the researchers don’t advocate continuing anticoagulation medication during high-risk operations like intracranial and spinal procedures, studies and guidelines support their recommendation of not stopping blood thinners for less serious surgeries ranging from dental procedures to cardiac device implantations. They suggest that doctors address interrupted treatment due to nursing errors and patient refusal by educating both groups on the risks.
This study’s significant findings instigated a quality improvement measure at the team’s hospital. The researchers trained surgeons about the adverse consequences of missed doses. These interventions reduced the percentage of withheld doses.
Post-Surgical Prevention Program Decreased Blood Clots
The Boston Medical Center surgical quality improvement study reduced the odds of patients developing blood clots in their lower extremities or lungs. Researchers tested a multicomponent prevention program that included anticoagulants on all patients undergoing general and vascular surgery procedures. Investigators compared VTE incidences two years before and after implementing the prevention program in February 2011. DVT frequency declined by 84 percent, and pulmonary emboli occurrence decreased by 55 percent.
Pre-program odds of a patient having post-op VTE were 3.4 times worse than the investigators expected, after adjusting for patient risk. Two years into the program, this risk dropped to 0.94, better than they anticipated. DVT frequency declined from 1.9 percent of 1569 patients to 0.3 percent of 1323 patients. Pulmonary emboli rates fell from 1.1 percent of 1569 patients to 0.5 percent of 1323 patients.
Positive Results May Help Other Hospitals
Co-investigator David McAneny, M.D., FACS, vice chair of surgery, and other researchers developed the venous thromboembolism (VTE) prevention program to make sure that high-risk patients get necessary treatment. Initially, they emphasized early postoperative mobilization. Following surgery, patients walked three times a day whenever possible.
Later, the study team expanded the program to include these components:
- Mandatory electronic reminders regarding VTE prevention for surgical teams before and after operations and at patient discharge
- Electronic physician orders specifying individualized risk-based prevention plans including blood-clotting risk assessments, early mobilization, inflatable pressure boots and/or low-dose anticoagulation medications with suggested hospital durations (and at-home continuation periods for patients with high risk scores)
- Patient education on the importance of blood clot prevention
Physician compliance rates for ordering VTE blood thinners were 100 percent for patients at low or moderate risk and 77 percent for those at the highest risk levels. When opting out of prescribing recommended preventive medications, doctors had to indicate their reasons. Patient record explanations included drug allergies, active bleeding, and hemorrhage risks outweighing VTE chances. Dr. McAneny noted that the prevention program’s success at combining individualized risk assessments, early ambulation, and preventative treatments may serve as a model for other hospitals.