Kosir MA, Kozol RA, Perales A, McGee K, Beleski K, Lange P, Dahn M.
Is DVT prophylaxis overemphasized? A randomized prospective study.
J Surg Res 1996 Feb 1;60(2):289-92

VA Medical Center, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.

This study was designed to prospectively evaluate a previously published
prognostic index for predicting deep venous thrombosis (DVT) in general surgical
patients with conventional prophylaxis. Patients undergoing procedures of at
least 1 hr duration (abdominal, thoracic, head and neck, inguinal) requiring
general or spinal anesthetic were prospectively randomized into the following
groups: Group 1, sequential pneumatic compression devices during surgery and 2
days postoperatively; Group 2, subcutaneous heparin (5000 U q 12 hr) starting 1
hr before surgery and for 7 days postop; Group 3, control group. All patients
underwent duplex evaluation of bilateral lower extremity deep venous systems
preoperatively and on postoperative Days 1, 3, and 30. In addition, a previously
developed predictive DVT incidence indicator, the prognostic index (PI), was
calculated for each patient. A total of 137 patients were entered into the study
with 29 removed for patient/staff reasons. There were no differences in PI among
the three groups at the 0.05 level (ANOVA). The distribution of risk factors for
DVT including increased age, body size, hemoglobin (Hb), and colorectal
procedures were distributed evenly among the groups. Additional factors such as
diabetes, COPD, PVD, immobilization, and cancer were also evenly distributed
among the groups. The PI predicted a 20% incidence of DVT. For Groups 1 (n = 25),
2 (n = 38), and 3 (n = 45) no DVTs were detected over the 30 days of study.
During the study period, 8 DVTs were detected by duplex evaluation in general
surgical patients not in the study (1.5%). In conclusion, in a prospective
randomized study using sequential pneumatic compression devices, subcutaneous
heparin or no prophylaxis in matched general surgical patients at moderate to
high risk for thromboembolism, no DVTs occurred for up to 30 days. Furthermore,
neither a PI nor other factors associated with DVT accurately predicted the
incidence of DVT in this patient population.