Impact of Opioid Free Anesthesia on Outcome After Hip Arthroplasty by Direct Anterior Approach.

Randomized Controlled Trial Study in Hip Arthroplasty by Direct Anterior Approach Using Opioid Free Anesthesia (OFA) Versus Standard Opioid Anesthesia.

all patients with a first anterior arthroplasty, give their informed consent to be randomized to control or study protocol.

control means no high steroid dose, opioids for anesthesia; paracetamol, NSAIDs and opioids as analgesia.

study protocol means methylprednisolone 125 mg and opioid free anesthesia followed by paracetamol, NSAIDs and if needed opioids as escape.

study group means for Anesthesia:

1. High dose corticoids pre-operative: 125 mg Methylprednisolone. (Medrol) pre incision and 24h postoperative
2. OFA using a multimodal approach including alpha2agonists, lidocaine and low dose ketamine (max 1mg/kg).
3. Avoid opioids post-operative by using multimodal non-opioid analgesics after OFA. Avoid epidural to allow rapid mobilization.

all patients get Tranexamic acid 1 g (2 amp Exacyl 500mg) before and 1 g after surgery. It act as antifibrinolytic to reduce postoperative bleeding. (reversibly binding to lysine receptor sites on plasminogen) Try to give Continuous deep neuromuscular block (NMB) with a post titanic count (PTC) < 3 by continuous infusion and monitoring of NMB.

Intravenous Fluid restrictions to 1 ml/kg/h as long as pulse pressure (or plethysmograph) variation < 20% to reduce wound edema.

The pericapsular injections of local anesthetic, provided the patient had no contraindications such as poor renal function or allergies. 100 ml Ropivacaine 0,2% (max dose 3 mg/kg) + additives (Adrenaline 2,5 cc) (Ropivacaine: max 3 mg/kg)

Inclusion Criteria:

• arthroplasty by anterior approach

Exclusion Criteria:

• allergy or impossible to use any of the drugs included
• revision procedure
• major cardiovascular, pulmonary or renal insufficiency requiring planned post operative intensive care admission