Total Hip Replacement

A 200 mL 2 mg/mL (0.2%) infusion bag of ropivacaine is split as follows:-

50mLs to the anterior capsule, inferior capsule & gluteus minimus tendon after insertion of acetabular component.

50mL to the posterior capsule/short external rotators (SERs)/gluteus medius tendon & IT band after insertion of femoral component.

50mL subcutaneously prior to wound closure.

Catheter inserted & laid on top of SERs & above piriformis (under posterior aspect of gluteus medius/minimus & 20mL injected after wound closure.

Gabapentin 300 mg 2 hours orally pre-op (Omit pre-op dose in those with renal impairment)

Paracetamol 1g orally

Single shot spinal 2.5-3.0 m mLs Bupivicaine plus TCI propofol for sedation (or a light GA if anaesthetist prefers)

Ondansetron 4mg iv

Dexamethone 8 mg iv

Diclofenac 75 mg iv if tolerated

Tranxenamic acid 1 gram to minimise blood loss - has 120 minute half-life so give just before tourniquet goes down for TKR and just after incision is made for THR

No opiates

No urinary catheter.

Limit fluids to ~ 1 litre intraop if possible.

Surgeon infiltrates with 150 -200 mLs of 0.2% ropivacaine at end of operation.

Surgeon places peri-articular catheter Catheter must be clearly labelled “peri-articular catheter

Infusion set up with McKinley pump.

Ropivacaine 0.2% 200 mLs.

Give 20 mL bolus and set at 5-8 mLs/ hour-

Written by Dr L S Barker

Updated 26/06/10

Bleep 1235

Knee Surgery

Rasmussen et al (2004) open study of 154 patients – 4 groups, 3 of which received intra-articular morphine and ropvacaine. Primary outcome – range of motion and LOS reported as improved and reduced respectively (statistically but no numeric data provided).

Isaac et al (2005) randomised 50 patients undergoing total knee arthroplasty to either standard care or a technique using a local anaesthetic infiltration. Along with this technique there was a restructuring of the service; prior to this the median length of stay was 10.5 days. The median length of stay after the restructuring in the control group was reduced to 6.6 days whereas the infiltration was reduced down to 3.6 days.

Busch et al (2006) randomised 64 patients to infiltration or standard care. They report better analgesia and reduced opioid analgesic requirements.

Toftdahl et al (2007) randomised 80 patients receive either a femoral nerve block (using ropivacaine) or peri-/intra-articular local anaesthesia infiltration. The latter comprised of 50mL of 0.2% ropivacaine into both the anterior and posterior capsule and then 50mL in to the subcutaneous tissue around the surgical field. Outcomes measured on postoperative day 1 showed increased ability to mobilise with the new technique and this continued to day 2 (outcome results for after POD 2 are not reported)

On day 1 there was a reduction in opioid consumption but over a 4 day postoperative period there was a non-significant difference.

Median length of stay for infiltration was 1 day less than nerve block (5 versus 6 days (non-significant)

Hip Surgery

Andersen et al 2007 compared the local infiltration technique against epidural in patients undergoing total hip replacement. Morphine consumption was significantly reduced during the first 20 hours post-operative (26 mg for the epidural group versus 17.5mg for the infiltration group (p=0.004)). Length of stay was also significantly reduced from 7 to 4.5 days. They also monitored motor function using the Bromage scale and this indicated no reduction in motor function with the infiltration technique but significant effects from the epidural (50% of patients affected).

Husted et al (2008) followed 712 patients

undergoing hip or knee surgery and report a median length of stay of 3.8 days with 41% of patients being discharged by day 3 and 92% of patients being discharged by 5.

Kerr & Kohan (2008) followed 325 patients and also report 67% of their hip patients being discharged on day 3 or before and 84% of their knee patients. They also report that a significant amount of their patients did not require extra morphine.

Chondrocyte toxicity

Intra-articular local anaesthetics have been associated with toxicity to the chondrocytes and to the cartilage. Piper and Kim (2008) using an in vitro study looked at ropivacaine versus the other most common local anaesthetic used in this technique, bupivacaine. In cartilage explants chondrocyte viability was shown to be 94.4% for ropivacaine and 78% for bupivacaine (viability in 0.9% sodium chloride was 95.8%). They also looked at cultured chondrocytes and the viability for ropivacaine was 63.9% versus 37.4% for bupivacaine.

Costs

Ropivacaine 0.2% ampoules 10mL – £9.50 for 50mL (£38.00 for 200mL)

Ropivacaine 0.2% infusion 200mL – £16.78 for 200mL

The studies that have been performed using this technique indicates that there is reduced opioid requirements, increased mobility, reduced length of stay, and those that have measured it there is also an increase in patient satisfaction.

Ropivacaine (Naropin) was introduced onto the market in 1995 as a long acting amino-amide local anaesthetic, similar in onset, potency and duration of action to that of Bupivacaine. It offers a greater margin of safety when compared to racemic bupivacaine in terms of its cardiotoxic and central nervous system toxic effects. Studies show that the threshold for CNS toxicity for ropivacaine is approximately twice the plasma concentration than the threshold for bupivicaine.

It is for this reason that it has become the drug of choice when using it for the large volumes of dilute local anaesthetic that are used with peri-articular infiltration.

It is well demonstrated that the site of administration and consequently rate of plasma absorption is the most important indicator of the potential for local anaesthetic toxicity. For example, the rate of absorption from the brachial plexus is thought to be far greater than that from periarticular tissues. Most cases of acute local anaesthetic toxicity described in the literature arise from inadvertent intravascular injection of the local anaesthetic. Again this occurs most commonly in brachial plexus blocks. The potential for inadvertently injecting toxic amounts of ropivacaine intravascularly with this technique is minimal as it is injected under direct vision in aliquots of 50-70 mLs over a period of 30 minutes.

These factors explain why large numbers of cases worldwide have been reported using 300-400mg of Ropivacaine injected peri-articularly with no adverse effects. In all studies using periarticular injections of doses greater than the manufacturers recommendations measured plasma levels were below toxic limits and no symptoms of toxicity occurred. The safety of periarticular administration can be attributed to is sequestration in the tissues and hence a slow uptake into plasma and also the rise in alpha globulins after surgery which binds the drug molecule and leaves less unbound drug to cause toxicity.

• Vendittoli et Al measured plasma levels in 22 patients receiving 400 mg Ropivacaine peri-articularly and all the plasma levels measured were lower than 1.5 micrograms/mL. Some studies have reported mild central nervous system toxicity at 1.5 micrograms/mL but this was after intravenous administration.
• Wiedermann et Al reported no symptoms of systemic toxicity after epidural administration with plasma concentrations of 6.08 micrograms/mL.
• Burm et Al reported a very high total plasma ropivacaine concentration (7.1 micrograms/mL) with no systemic adverse effects during 72 hours of epidural ropivacaine infusion.
• Wulf et Al reported no symptoms of toxicity with a cmax of 3.7 micrograms/mL after iliohypogastric block
• Petterson et al evaluated wound infiltration of ropivacaine for hernia repair surgery with 375 mg of ropivacaine. The highest recorded maximum plasma concentraton was 3.0 micrograms/ mL with no evidence of systemic adverse events.

STAT dose of Gabapentin 300mg (Omit in those with renal impairment)

PLUS Paracetamol 1g PO pre-op

Post op Caledonian medications

Regular – NB if patient on regular opiates pre-admission ask pain team for advice

Paracetamol 1g PO qds

Gabapentin300 mg bd for 3 - 5 days – Omit in renal impairment – for individual assessment)

(100 mg bd in >70 years) (Stop on discharge or before if drowsy)

Oxycontin MR tablets 10 mg bd – review need at 48hours max course 3 – 5 days

(5mg bd in >80 years/renal impairment (eGFR < 30mL/min))

Ibuprofen 400 mg tds (If NSAIDS tolerant – i.e. no recent history of NSAID induced asthma;

GI problems; renal impairment or heart failure)

Laxatives if necessary – Senna 15mg ON and Lactulose 10mL BD

à Then after 5 days or on discharge stepdown analgaesia

Codeine phosphate 30 - 60mg qds or dihydrocodeine 30mg 4-6 hourly

PRN

Oramorph (morphine sulphate 10mg/5mL solution) 5 -10 mg prn 2 hourly for breakthrough pain

(5mg prn 2 hourly > 80 years)

(2.5-5 mg prn 4hourly if eGFR <15mL/min and titrate according to response)

Cyclizine 50mg TDS po/im/iv prn

Ondansetron 4mg bd/tds po/iv prn (maximum of 2 doses)

Ephedrine 30mg PO prn (for dizziness on attempting to mobilise as per protocol.

No history of IHD and Hb > 8.0g/dL)

Please also prescribe sc/im morphine 5mg max 4hourly prn for escape analgesia

On discharge

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