At our district general hospital in the southwest of England, around 694 total knee replacements (TKR) are performed annually. Since spring 2013 we have been using an enhanced recovery protocol for all TKR patients, yet we have neither assessed compliance with the protocol nor whether its implementation has made a discernible and measurable difference to the delivery of care in this patient population. Enhanced recovery after surgery (ERAS) protocols are multi-modal care pathways designed to aid recovery. They are based on best evidence and promote a multi-disciplinary approach which standardises care and encompasses nutrition, analgesia and early mobilisation throughout the pre, intra and postoperative phases of an inpatient stay. ERAS has been found to reduce length of stay (LOS), readmission rates and analgesic requirements following surgery. 1, 2, 3. Additionally, they have been shown to improve range of knee movement following TKR and improve mobility, patient satisfaction whilst reducing mortality and morbidity. 4, 5, 6. With these benefits in mind, we sought to investigate how well our trauma and orthopaedic department was complying with a local ERAS protocol and whether we could replicate the benefits seen within the literature. Following approval from our local audit office in September 2015 we generated a patient list of elective TKR patients under the same surgeon before and after the implementation of the ERAS protocol. Using discharge summaries and patient notes we extracted data for 39 patients operated on prior to the ERAS implementation between January 2011 and December 2012 and 27 patients following its introduction between January 2014 and September 2015. Data collected included length of stay, time to discharge from inpatient physiotherapy and use of analgesia and antiemetics. Alongside this we audited the compliance with all facets of the local ERAS protocol. There was no statistically significant difference between the 2 groups in terms of demographics or pre-operative morbidity. Overall compliance with the ERAS protocol was good but there was some variability, especially with intraoperative medication and type of anaesthesia which was likely due to individual patient factors. Compliance with postoperative analgesia was especially good with 93% of patients receiving all 4 suggested analgesics within the ERAS group. Length of stay (LOS) was significantly reduced by 0.5 days per patient (p value < 0.4). Overall compliance with the ERAS protocol was good but there was some variability, especially with intraoperative medication and type of anaesthesia, which was likely due to individual patient factors. Compliance with postoperative analgesia was especially good with 93% of patients receiving all suggested analgesics within the ERAS group. In terms of LOS, we found a statistically significant difference between the pre-ERAS and ERAS group of 0.5 days per patient. Within the context of our DGH, a 0.5 day reduction in LOS translates to around 350 bed days per year and a potential saving of GBP 105,000 (EUR 132,000) making this a clinically significant finding

Background. Predicting length of stay (LOS) is key to providing a cost effective and efficient arthroplasty service in an era of increasing financial constraint. Previous studies predicting LOS have not considered enhanced recovery protocols in elective hip and knee arthroplasty. Our study aims to identify patient variables in the pre and peri-operative period to predict increased LOS on patients enrolled into the standardised Chichester and Worthing Enhanced Recovery Programme (CWERP). Methods. All patients undergoing elective hip and knee arthroplasty were enrolled into CWERP using standardised anaesthetic, surgical and analgesic protocols. A data analyst prospectively collated data over 6months from anaesthetic charts and daily ward review from 663 patients between Dec 2012 and June 2013. An independent statistician undertook statistical analysis (program R, version 3.1.1). 80% of the 6months consecutive data (530 patients) were analysed, and predictive variables identified. These variables were tested against the remaining 20% of data (133 patients) predicting a LOS greater or less than our median of 4 days. Results. 663 patients were enrolled into CWERP over this period, 54% in hip arthroplasty. Statistical analysis was performed using Chi-squared test for association between actual and predicted (dichotomised) LOS being significant (p<0.0000000017). In the initial 80% (530 patients), this identified the following statistically significant variables in predicting LOS > 4 days: Age > 80 yrs, ASA 4, failure to mobilise on day of surgery, urinary catheterisation and need for blood transfusion. The statistical model when applied to the remaining 20% (133 patients) correctly categorised LOS in 101 (76%) of the patients. Conclusions. Identifying patients who fulfil our variables in the preoperative period affords better planning, maximising resources, bed efficiency and discharge planning. This also provides opportunities for financial remuneration for higher risk patients. Level of Evidence. 4

Post-operative regimes involving the use of intra-articular local anaesthetic infiltration may allow early mobilisation in patients undergoing total knee arthroplasty. Few studies have evaluated such regimes outside specialist arthroplasty units. We aimed to determine whether an enhanced recovery programme including the use of local anaesthetic administration could be adapted for use in a district general setting.

Following introduction of this regime to our unit, 100 consecutive patients undergoing primary total knee arthroplasty were reviewed. 56 patients underwent a standard analgesic regime involving a general or spinal anaesthetic and oral analgesics post operatively (group1). 48 patients underwent the newly introduced regime, which included pre-operative counselling, peri-articular local anaesthetic infiltration at operation and intra-articular local anaesthetic top-up administration post-operatively for 24 hours (group 2). Length of stay, post-operative analgesic requirements, and range of knee motion post-operatively were compared.

Median length of stay was less for patients in group 2 compared with those in group 1 (4 days compared to 5 days, p<0.05). Patients in group 2 required lower total doses of opiate analgesia post-operatively. 90% of patients in group 2 were ambulant on the first post operative day, compared with less than 25% of patients in group 1. Mean knee flexion on discharge was greater in patients in group 2 compared with those in group 1 (85 degrees compared with 75 degrees). No infective complications from intra-articular catheter placement were observed. However, technical difficulties were encountered during the introduction period, including loss of catheter placement, leakage of local anaesthetic and adaptation of nursing time for top-up anaesthetic administration.

A rehabilitation regime involving local anaesthetic infiltration for total knee arthroplasty can successfully be adapted for use in a district general setting. Our results suggest if initial technical difficulties are overcome, this regime can provide effective postoperative analgesia, early mobilisation and reduced hospital stay.

We reviewed renal function of 22 patients who had undergone total knee replacements using the enhanced recovery protocol (Caledonian technique) between August 2012 and November 2012 at a district general hospital in the west of Scotland. Pre-operative and post operative data were compared to determine if there was any change. We observed that 4 out of 22 (18%) of patients had a significant rise in creatinine, and 6 out of 22 (27%) had an abnormal eGFR. These findings were significant and were classed as (Acute Kidney Injury) AKI type 1, which should be treated actively.

Subsequently, we collected data in the same way for 22 patients who underwent total knee replacements without using the enhanced recovery protocol. In this group, only one (5%) had a significant rise in creatinine and 2 (9%) had an abnormal eGFR.

Significant difference is noted in the two groups.

We conclude that the enhanced recovery protocol has some adverse effect on a patient's renal function. Our hypothesis is that this is due to restriction of fluids after surgery but a larger study is needed to find the cause and ways to avoid this.