Clinical use of parnaparin in major and minor orthopedic surgery: a review.

Patients undergoing arthroplasty or other orthopedic surgery show a high risk of venous thromboembolism (VTE), involving mortality, morbidity, and social costs; however, the risk for VTE in minor orthopedic surgery should not be underestimated and antithrombotic prophylaxis may be required. According to the literature, low-molecular-weight heparins (LMWHs) are more effective in preventing VTE than unfractionated heparins (UFHs) or vitamin K antagonists, and have a lower hemorrhagic risk. By comparing different prophylactic regimens, it has been shown that starting the prophylaxis near the time of the operation is the most critical point for efficacy, whether or not the first dose is administered pre- or post-operatively. Moreover, most thromboembolic complications are observed after discharge and, therefore, many clinicians advocate continuing prophylaxis for longer times (6-8 weeks) in order to further reduce the rate for VTE. The literature on parnaparin, a new LMWH, in VTE prophylaxis was reviewed. Parnaparin is equally effective as UFH, but it offers the advantages of a once-daily administration and improved tolerability, thus allowing the home management of patients with no need for laboratory coagulation tests.

Prophylaxis of venous thromboembolism in minor orthopedic surgery with parnaparin.

This study analyzed the efficacy of venous thromboembolism prophylaxis in knee arthroscopy in 509 patients who received Parnaparin (Alfa Wassermann, Bologna, Italy), 3200 IU to 4250 IU daily, after minor arthroscopic knee surgery. No proximal deep venous thrombosis or other thromboembolic events occurred. Adverse events related to the treatment with Parnaparin were observed in 2 of 172 patients treated with 3200 IU/d and in 6 of 337 patients treated with 4250 IU/d, without any evidence of dose-proportionality in the incidence. Prophylaxis with a low-molecular-weight heparin such as Parnaparin should be considered in all patients who will be undergoing a procedure in which a tourniquet is used. If Parnaparin is used, it should be started immediately after knee arthroscopy at doses of 3200 to 4250 IU/d, according to the characteristics of the patients. Depending on the patient's risk factors, postoperative prophylaxis for 10 days may be appropriate.

Unilateral spinal block for outpatient knee arthroscopy: a dose-finding study.

STUDY OBJECTIVE: To evaluate the onset time, success rate, and recovery profile of unilateral spinal anesthesia produced with 4 mg, 6 mg, and 8 mg of 0.5% hyperbaric bupivacaine. DESIGN: Prospective, randomized, blinded study. SETTING: Outpatient anesthesia unit at a University Hospital. PATIENTS: 90 ASA physical status I and II outpatients, who were scheduled for elective knee arthroscopy. INTERVENTIONS: After standard intravenous midazolam premedication (0.05 mg/kg) and crystalloid infusion (7 mL/kg) were given, patients were placed in the lateral decubitus position on the operative side, and randomly allocated to receive spinal block with either 4 mg (Group 4, n = 30), 6 mg (Group 6, n = 30), or 8 mg (Group 8, n = 30) of 0.5% hyperbaric bupivacaine injected slowly (3 mL/min) with the needle orifice directed toward the dependent side using a 25-gauge Whitacre needle. The lateral decubitus position was maintained for 15 minutes. MEASUREMENTS AND MAIN RESULTS: The onset time of surgical block was 13 +/- 5 minutes in Group 4 and 10 +/- 4 minutes in Group 6 (p = 0.006), and 9 +/- 4 minutes in Group 8 (p = 0.002). The maximum level of sensory block on the operative and nonoperative sides was, respectively, T(10) (T(12)-T(6)) and / (/-L(2)) in Group 4 (p = 0.0005), T(8) (T(12)-T(6)) and / (/-L(5)) in Group 6 (p = 0.0005), and T(7) (T(12)-T(5)) and / (/-T(10)) in Group 8 (p = 0.0005). A strictly unilateral sensory block was observed in 27 Group 4 patients (90%), 28 Group 6 patients (93%) and 23 Group 8 patients (77%) (p = 0.28). Complete unilateral motor block was observed in 29 Group 4 patients (97%), 28 Group 6 patients (93%), and 28 Group 8 patients (93%) (p = 0.80). No failed blocks were reported. Complete regression of spinal anesthesia required 71 +/- 20 minutes in Group 4 (range: 40 to 110 min), 82 +/- 25 minutes in Group 6 (range: 30 to 160 min), and 97 +/- 37 minutes in Group 8 (range: 50 to 120 min) (p = 0.003). CONCLUSIONS: Hyperbaric bupivacaine 4 mg injected slowly through pencil-point directional needles in patients who are maintained in the lateral decubitus position for 15 minutes provided a surgical block that was mostly restricted to the operative side and adequate to perform knee arthroscopy, with a faster recovery profile than when a 6 mg or 8 mg dose was used.