Timing of DVT prophylaxis and risk of postoperative knee prosthesis infection.

This multicenter prospective study was performed to determine risk factors for knee prosthesis infection and the effect of timing doses of prophylactic low-molecular-weight heparins (LMWH) related to time of surgery on the risk of knee prosthesis infection. A total of 5496 consecutive patients who underwent total knee arthroplasty from 2005 to 2006 in 13 orthopedic centers were prospectively followed up for 6 months, and the incidence of knee prosthesis infection was recorded. A case control study was nested in the cohort. Case patients were matched to uninfected (control) patients, and the timing of perioperative LMWH was recorded as the main risk factor. Fifty patients developed postoperative knee prosthesis infection during the follow-up period, yielding an incidence of prosthesis infection of 0.91% (95% CI, 0.68%-1.20%). Forty-four patients were matched to 106 controls. Case patients received the first LMWH dose ±12 hours from the start of surgery more frequently than their control counterparts (odds ratio, 1.5; 95% CI, 0.73-3.0). After adjusting by main risk factors, no statistical association was found between close perioperative timing of LMWH and risk of prosthesis infection. Diabetes mellitus (adjusted odds ratio, 3.2; 95% CI, 1.2-8.8) and wound hematoma (adjusted odds ratio, 4.2; 95% CI, 1.1-16.5) were found to be independent risk factors for prosthesis infection.

Preoperative haematinics and transfusion protocol reduce the need for transfusion after total knee replacement.

BACKGROUND: Unilateral total knee replacement (TKR) can result in a substantial blood loss and 30-50% of these patients receive allogeneic blood transfusion (ABT), this transfusion rate may be even higher among anaemic patients. PATIENTS AND METHODS: We assessed the requirements for ABT in 156 consecutive patients undergoing surgery for primary TKR, who received iron ferrous sulphate (256 mg/day; 80 mg of Fe(2+)), vitamin C (1000 mg/day) and folic acid (5mg/day) during the 30-45 days preceding surgery, and who were transfused if Hb <80 g/L and/or clinical signs/symptoms of acute anaemia/hypoxemia (Group 2). A previous series of 156 TKR patients serves as a control group (Group 1). RESULTS: Compared to those in Group 1, patients in Group 2 presented a lower transfusion rate (5.8% vs. 32%, for Group 2 and Group 1, respectively; p<0.01), and a lower transfusion index (1.78+/-0.44 vs. 2.22+/-0.65 units per transfused patient, respectively; p<0.05). After patient's stratification according to a preoperative Hb above or below 130 g/L, the differences in transfusion rate remained significant, although 19% of patients from Group 2 still needed ABT if their preoperative Hb <130 g/L. CONCLUSION: This protocol seems to be effective for avoiding ABT in non-anaemic TKR patients, whereas for anaemic patients another blood saving strategy, such us preoperative erythropoietin administration or postoperative blood salvage, should be added to further increase its effectiveness.

Perioperative intravenous iron, with or without erythropoietin, plus restrictive transfusion protocol reduce the need for allogeneic blood after knee replacement surgery.

BACKGROUND: Unilateral total knee replacement (TKR) results in a substantial blood loss and 30 to 50 percent of patients receive allogeneic blood transfusion (ABT). Therefore, the effectiveness of a restrictive transfusion trigger (hemoglobin [Hb] level < 8 g/dL) plus stimulation of erythropoiesis was evaluated, with or without blood salvage, for reducing ABT in TKR patients. STUDY DESIGN AND METHODS: A series of 139 consecutive of primary TKR patients received perioperative iron sucrose (2 x 200 mg/48 hr, intravenously [IV]), plus preoperative erythropoietin (EPO; 1 x 40.000 UI, sc) if preoperative Hb level was less than 130 g per L (Group A). This protocol was applied to another series of 173 consecutive TKR patients who also received postoperative unwashed shed blood (USB) if preoperative Hb level was less than 130 g per L (Group B). Perioperative clinical and laboratory data were gathered. RESULTS: No adverse effects of iron sucrose, EPO, or USB administration were witnessed, and only 13 patients received ABT overall (4%). No major differences in perioperative blood counts or iron metabolism variables were observed between groups, but stimulation of erythropoiesis seemed to be more pronounced in those patients receiving EPO (p < 0.05). There were no differences in postoperative complications between groups, but length of hospital stay for patients with a preoperative Hb level of less than 130 g per L was shorter in Group B (p < 0.05). CONCLUSION: This blood saving protocol seems to be effective for reducing ABT in TKR patients. Which patients are more likely to benefit from either perioperative iron administration or selective addition of postoperative blood salvage to pharmacologic treatment, however, needs to be further evaluated.