Local infiltration analgesia (LIA) gives superior analgesia compared to epidural analgesia after total knee replacement.

Scharlaeken I 1,2, Van Overschelde P 3, Byn P 3, Allaert S 1, Van de Velde M 2, Kalmar AF 1
1 Maria Middelares Hospital, Dept of Anesthesia & Intensive Care, Gent, Belgium
2 University Hospitals Leuven, Katholieke Universiteit Leuven, Dept of Anesthesia, Leuven, Belgium
3 Maria Middelares Hospital, Dept of Orthopaedics, Gent, Belgium,

Background and Goal
Local infiltration analgesia (LIA) is an emerging alternative for patient controlled epidural analgesia (PCEA) for postoperative pain relief after total knee replacement. LIA allows faster mobilisation - with beneficial orthopaedic results-, obviates an urinary catheter, eliminates the risks of epidural catheters, and fastens patient turnover. Conversely, PCEA is considered the gold standard
for pain relief in the first days after this type of surgery. The aim of this observational study was to
evaluate patient perception of the quality of analgesia, postoperative nausea & vomiting, and general comfort.

Materials and Methods
81 patients undergoing a total knee replacement between April and July 2015, were asked about pain scores at D0, D2, and D7, PONV, and general comfort. 40 patients received PCEA and 41 patients received LIA (70ml Ropivacaine 2%, ketorolac 30mg and adrenaline 0.4mg). All surgeries were performed using the same surgical technique by two orthopaedic surgeons, under a standardised general anaesthesia. Spinal anaesthesia with 2.5 ml levobupivacaine 0.25% was given prior to induction of general anesthesia, associated with either PCEA (levobupivacaine / sufentanil) for three days, or LIA during surgery, according to the preference of the surgeon. A strict protocol for other analgesic medication (paracetamol, NSAID and tramadol) was applied in all patients in both groups.

Results and Discussion
The figure summarizes the results in box-plots. The dots represent the average values. The asterisks represent a significant difference.
At D0, no significant difference in pain scores was reported. Patients in the LIA group reported significantly better pain scores at D2 and D7 and PONV scores. General comfort was not significantly different (F-test : P=0.054). In addition to significantly better average scores in the LIA group, a remarkably favorable 75th percentile for most questions indicates a much lower incidence of the most extreme discomfort in this group.

Conclusion
In addition to faster mobilisation of the patients and elimination of the risks and burden of an epidural catheter and PCEA, LIA delivers equal to better analgesia, and better PONV and general comfort scores.

References
1 Kerr DR, Kohan L. Local infiltration analgesia: a technique for the control of acute postoperative pain following knee and hip surgery: a case study of 325 patients. Acta Orthop. 2008 Apr;79(2):174-83.