Prospective double-arm study of fibrinolysis in surgical patients.

BACKGROUND: During surgery, the balance between thrombosis and fibrinolysis is altered. Methods reported to increase fibrinolysis, such as compression devices, may reduce venous thrombosis. However, there are no prospective studies comparing methods and the effect on fibrinolysis. MATERIALS AND METHODS: In a prospective study, general surgical patients were randomized to either sequential compression devices (Group 1) or subcutaneous heparin (Group 2), and fibrinolysis factors were measured in order to determine the effect on the fibrinolysis system. Blood samples were drawn at a similar time of the day with the tourniquet off. Specifically, t-PA antigen, plasminogen activator inhibitor-1 (PAI-1), and D-dimer were measured preoperatively (preop) and on Postoperative Days (POD) 1 and 7 by the ELISA method. Fibrinolysis factors were reported as the mean +/- SD and as percentage change from preoperative values. Noninvasive vascular studies were performed preop, and on POD 1, 7, and 30, by an examination of the infrainguinal venous system and external iliac veins in bilateral lower extremities. Nonambulatory patients were excluded from the study and DVT prophylaxis methods were initiated at surgery and used through POD 2. RESULTS: For the 136 patients in the study, there were no differences in clinical characteristics such as age, surgical time (all > 60 min), anesthesia type (general or spinal), type of surgical procedure, or other risk factors for DVT. Two DVTs occurred at POD 1 and 30 (both Group 2), and one pulmonary embolism in each group (POD 7 for Group 1; POD 1 for Group 2). For subjects without thrombosis, D-dimer changes were parallel for both groups, increasing through POD 7. Similarly, t-PA antigen levels rose from baseline on POD 1 in both groups, with a return toward baseline by POD 7. The PAI-1 levels increased on POD 1 in both groups, but severalfold more in Group 1 (compression devices). The elevation in PAI-1 decreased by 50% in Group 1 by POD 7, while values returned to normal in Group 2. These changes were not significant using the Mann-Whitney test. Only three patients had thrombotic episodes so that data on changes in fibrinolysis factors are difficult to compare with the larger group. CONCLUSIONS: This is the first report of a prospective, randomized comparison of fibrinolysis factors using sequential compression devices in comparison to low dose unfractionated heparin in general surgical patients, and comparing postoperative values to preop. Both groups showed an enhanced fibrinolysis by elevation in t-PA antigen and D-dimer on POD 1, as expected when fibrinolysis occurs. While PAI-1 and t-PA work in parallel, the marked elevation of PAI-1 on POD 1 (although only slightly above reference values) and continuing into POD 7 for subjects using compression devices requires further inquiry. The elevation of PAI-1 in the face of elevated t-PA and D-dimer has been reported, but the comparison between patients using sequential compression devices and mini-dose heparin has not been reported. The reason for the elevation requires additional study into other influences on the synthesis, secretion, and/or function of PAI-1 that do not affect t-PA.

A prospective, randomized study of open vs laparoscopic inguinal hernia repair. An assessment of postoperative pain.

OBJECTIVE: To compare postoperative pain after laparoscopic hernia repair and conventional open hernia repair. DESIGN: Prospective, randomized study. SETTING: Veterans Affairs Medical Center. PATIENTS: Sixty-two patients scheduled for elective inguinal hernia repair. INTERVENTIONS: Patients were randomized in the operating room to have a laparoscopic hernia repair (30 patients) or a conventional open hernia repair (32 patients). All operations were performed while the patient was under general anesthesia to avoid anesthesia as a confounding variable. MEASURES: Postoperative pain following laparoscopic hernia repair and open hernia repair were compared using the McGill Pain Score, the McGill Visual Analogue Pain Scale score, and the number of acetaminophen with 30-mg codeine sulfate (Tylenol 3) tablets needed for pain during the first and second 24-hour periods postoperatively. All of the patients were interviewed and the postoperative pain was evaluated by a special study nurse (P.M.L.) who was blinded to the repair technique. RESULTS: At 24 hours, the patients with laparoscopic hernia repair had 26% less pain by the McGill Pain Score (P = .02) and 31% less pain by the McGill Visual Analogue Scale (P = .006) than those who underwent an open hernia repair. At 48 hours the patients who underwent laparoscopic hernia repair had 28% less pain by the McGill Pain Score (P = .03), 42% less pain by the McGill Visual Analogue Scale (P = .002), and used 42% fewer analgesic tablets (P = .004). CONCLUSION: Patients with a laparoscopic hernia repair had significantly less pain postoperatively than those with standard open hernia repairs.

Is DVT prophylaxis overemphasized? A randomized prospective study.

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.