Preoperative administration of local infiltration anaesthesia decreases perioperative blood loss during total knee arthroplasty – a randomised controlled trial

PURPOSE: Local infiltration anaesthesia (LIA) consisting of ropivacaine, epinephrine and ketorolac administered at the end of surgery has become the gold standard for postoperative analgesia as it provides improved postoperative pain relief compared to other methods. The use of LIA has retrospectively been shown to be associated with decreased perioperative blood loss. However, no randomised controlled trials have examined the effect of of preoperative LIA on blood loss. This study aimed to compare pre- vs perioperative LIA during TKA surgery, with a primary outcome of perioperative blood loss. METHODS: The present study was performed as a prospective single-center randomised controlled trial. A total of 100 patients undergoing primary TKA between October 2016 and March 2018 were randomised to receive either pre- or perioperative LIA. Perioperative blood loss was measured, as well as pre- and postoperative haemoglobin levels. Postoperative pain was estimated at intervals approximately 24, 48 and 72 hours after surgery; analgesic drug consumption was recorded for each patient, as well as the total length of stay as an in-patient. RESULTS: Ninety six patients received either pre- or perioperative LIA as part of the intervention and control group respectively. Average blood loss was 39% lower in the intervention group at 130 ml vs 212 ml in the control group (p=0.002). No significant difference in haemoglobin drop, postoperative pain or length of hospital stay was found. CONCLUSIONS: Preoperative LIA resulted in a 39% decrease in perioperative blood loss during TKA surgery compared to perioperative administration while providing non-inferior postoperative pain relief.