To compare patients with increased risk of bleeding who received combined blood reinfusion and femoral nerve block in total knee replacement (TKR) to regular patients treated routinely with respect to pain relief, blood loss, and knee function.
In a consecutive series of 67 patients who underwent unilateral TKR, 12 patients with increased risk of bleeding owing to cardiac disease or previous thromboembolic events received continuous femoral nerve block and blood reinfusion, without tranexamic acid (TA) injection. The remaining 55 patients were controls who received standard postoperative treatment (TA injection, local injection of analgesics, and suction drainage without reinfusion). The volume of blood loss (drained or reinfused), pain score (using a visual analogue scale) and knee function (using the Knee Society Score [KSS]) in the 2 groups were compared.
In the study group, patients were 5 years older and tended to have a lower preoperative KSS function score (35 vs. 45, p=0.08) and a higher function-related pain score (6.5 vs. 6, p=0.10). The mean volume of drained blood wasted in the study group did not differ significantly from the mean total volume of drained blood in the control group (235 vs. 300 ml, p=0.14). Similarly, the mean decrease in postoperative haemoglobin concentration did not differ significantly between the respective groups (2.1 vs. 2.1 mmol/l, p=0.97). A significantly greater proportion of patients received allogenic blood transfusion in the study group than in controls (3/12 vs. 2/55, p<0.01). The study group exhibited significantly higher pain scores during training (1.7 vs. 1.4, p=0.03) and lower escape oxycodone consumption (5 vs. 15 mg/kg, p=0.06) on postoperative day 1 (but not other days). The duration of hospitalisation was also longer (5.5 vs. 4 days, p=0.04).
In TKR patients with increased risk of bleeding, blood reinfusion combined with femoral nerve block is safe and comparable to standard methods of pain control (local injection of analgesics).