Back

Clot Not: Preventing Blood Clots after Pelvic Injuries

Patients who have major pelvic injuries are at risk for developing deep vein thrombosis, blood clots that form in the veins. Without preventive care, the rate of thrombosis for patients with this kind of injury may be as high as 61 percent. This condition can be serious--even fatal. Pulmonary embolism, or a clot that breaks loose and travels into the lungs, is the most common cause of death beyond the first week of the initial pelvic injury.

Doctors have some reservations about medications to prevent blood clots. Since these drugs work to thin the blood, they can increase the risk of internal bleeding. There are a few mechanical devices that patients can use to prevent blood clots. In this study, the authors compared the effectiveness of two such devices.

These devices wrap around and squeeze the lower limbs, putting pressure on the blood vessels. This action keeps the blood moving, and can help prevent the formation of a clot. One device used in this study gave a low-pressure pulse, first to the calf and then to the thigh. The second device gave a high-pressure pulse to the calf and foot at the same time. The authors thought the second device would be more effective in preventing clots than the first.

Participants included 107 patients who had pelvic fractures. After surgery, half of the patients wore the low-pressure device; half wore the high-pressure device. There were no major differences between the two groups in the severity of their injuries or the amount of time it took for them to start treatment with mechanical devices.

All of the patients were told to wear the devices on both legs as much as possible while they were in the hospital. Before leaving the hospital, patients had tests to check for blood clots.

Fifteen patients (14 percent) developed clots. There were no deaths due to thrombosis. Ten of the patients with blood clots used the low-pressure thigh-calf device. Five others used the high-pressure calf-foot device. The difference between groups was slight, though patients who formed clots while using the low-pressure device seemed to develop larger, more serious clots.

Age seemed to heighten the risk for clots. Patients who had larger clots were an average of 11 years older than those who had no clots.

The more time that passed between injury and surgery, the more likely patients were to develop blood clots. Patients who formed clots averaged a ten-day delay between injury and surgery. Patients who had surgery within about five days were less likely to show signs of clots. More severe injuries to the pelvis tended to lead to larger blood clots. Regardless of the choice of device, mechanical compression helps lower the chance a blood clot will form.

The authors feel that their sample was not large enough to show the differences between the two mechanical devices. More research is needed to determine whether one type of device is more effective than the other.

References: James P. Stannard, MD, et al. Mechanical Prophylaxis Against Deep-Vein Thrombosis After Pelvic and Acetabular Fractures. In The Journal of Bone and Joint Surgery. July 2001. Vol. 83-A. No. 7. Pp. 1047-1051.

Back