Background and Aims At University Hospital Lewisham (UHL), a 450-bed district general hospital in South East London, we have observed an increase in the use of Infiltration between the Popliteal artery and Capsule of the Knee (IPACK) blocks in the last year, with anecdotal improvement in pain outcomes. We aim to compare the effectiveness of different regional anaesthetic techniques observed, in order to enhance patients’ acute pain management and recovery.

Methods Using SPSS software, we retrospectively analysed 100 patients who underwent total knee arthroplasty at UHL. The patients were identified using the Acute Pain Team’s review pro-forma which includes pre-admission analgesic requirement, morphine equivalent requirements (MER) at day 1 and 2, and pain assessment using Numeric Rating Scale (NRS). We used the electronic records system for tourniquet time and time to mobilisation. We subdivided patients into three groups: 1)IPACK+adductor canal block (ACB)+local infiltration of analgesia (LIA); 2)ACB+LIA; 3)LIA only.

Results There were no statistically significant differences in MER or in time to mobilisation between the groups. Although there was a decrease in NRS score at rest and during mobilisation on day 1, we did not detect any significant difference (table 1). However, the largest proportion of the patients with

>= 100mins tourniquet time (table 2) and pre-admission opioid use was found in group 1 (table 3).

Conclusions Our data, although suggestive, showed using IPACK blocks has no statistical benefit. IPACK blocks are growing in popularity; with increased regular practice and honing of technique, studies with a higher patient population may show statistical benefits.