Fibrinogen metabolism in patients with spinal cord injury

Deep venous thrombosis and pulmonary thromboembolism are common within weeks of spinal cord injury (SCI) but clinically uncommon in the chronically paralyzed. Fibrinogen half-life (FHL) and fibrin uptake of the legs (FUT), as indicators of an active thrombotic process, have been used to test this clinical impression.

Data from the use of autologous preparations of radioiodinated fibrinogen to determine FHL and FUT in 17 men paralyzed at cervical (6), thoracic (10), and lumbar levels (1), at ASIA grades A (15) and C (2) in 1974 to 1976 were reviewed. Group A consisted of 12 subjects 29 +/- 8 years of age and paralyzed 1 week to 5 months (median, 1 month). Group B consisted of 5 subjects 46 +/- 17 years of age and paralyzed 24 to 96 months (median, 36 months). Group B subjects were older and paralyzed longer than Group A. Group C consisted of 4 able-bodied control subjects enrolled at the same time for FHL studies, and these subjects were 34 to 38 years of age.

FHL was 61 +/- 14 hours for all SCI subjects and 95 +/- 23 hours for Group C (P = 0.001). Group A FHL was 59 +/- 16 hours, and FUT was positive in 8 of 12 subjects. Group B FHL was 66 +/- 7 hours, and FUT was positive in 3 of 4 subjects (1 FUT not done; P = 0.30 and 1.0, respectively).

Fibrinogen metabolism was abnormal in patients with acute SCI at high risk for pulmonary thromboembolism (PE) but continued to be abnormal beyond the high risk period for PE, possibly because of the greater age of the patients in the long-term paralysis group.