Changes in coagulatory profile after orthopedic surgery.

Platelet count, prothrombin time (PT), partial thromboplastin time (PTT) and fibrinogen concentrations were prospectively evaluated in 65 patients undergoing orthopedic surgery at the National Cheng-Kung University Hospital between June 1990 and February 1991. All patients were hospitalized for at least 7 days after surgery. Coagulation data were collected preoperatively and on the first, third and seventh postoperative days (POD 1, 3, 7). The average estimated blood loss was 374 mL (range, 25-2.350 mL). Stored whole blood transfusion of 2 to 5 units (1 unit = 250 mL) was required by 12 patients. A further 12 patients received a transfusion of two to six units of packed red cells. Platelet count decreased to the lowest level on POD 1, recovered to normal on POD 3 and was even greater by POD 7. PT was prolonged on POD 1, recovered by POD 3 and remained stable on POD 7. PTT was prolonged on POD 1, became more prolonged on POD 3 and returned to normal by POD 7. Fibrinogen concentrations were not significantly altered on POD 1, but increased above the preoperative level on POD 3 and returned gradually to normal by POD 7. Variables such as age, sex, type of operation and duration of tourniquet did not affect these patterns. There was a positive correlation between duration of surgery, net blood loss and decrease in platelet count. This study examined some of the physiologic coagulatory variations after orthopedic surgery. Recognition of these patterns might lead to better clinical judgment when perioperative coagulatory disorders are suspected.