Opioid-free Anesthesia and Acute Postoperative Pain

This study aimed to study postoperative pain after opioid free anesthesia or opioid based anesthesia after urologica; procedures. The two study groups opioid free (OFA) and opioid based (OBA) were as follows: OFA: Anesthesiology technique based on Mulier protocol. Before induction, loading dose of dexmedetomidine 0,25mcg/kg (max 20mcg). Induction with dexmedetomidine 0,1mcg/kg, lidocaine 1mg/kg, ketamine 0,1mg/kg plus propofol 2mg/kg plus rocuronium1mg/kg IBW (if required). Maintenance with dexmedetomidine 0,1mcg/kg/h, lidocaine 1mg/kg/h, ketamine 0,1mg/kg/h and propofol infusion adjusted according to bispectral index indication ( BIS maintained 40-60). 15 minutes prior to end of surgery, the dose of drugs is reduced to dexmedetomidine 0,05mcg/kg/h, lidocaine 0,5mg/kg/h, ketamine 0,05mg/kg/h. OBA: Total intravenous anesthesia with propofol for maintenance of anesthesia. Fentanyl 2mcg/kg only at induction and infusion of propofol and remifentanil for maintenance, with doses adjusted according to bispectral index indication ( BIS maintained 40-60). Both groups receive ranitidine 50mg, dexamethasone 4 mg and paracetamol 1g iv 15 min before the end of surgery. Postoperative analgesia for both groups consists of paracetamol 3g/24h iv, rescue analgesia with tramadol 1mg/kg iv max x3, rescue for PONV ondacetron 4 mg iv. The outcomes assessed were: Primary outcome: 1. Intensity of acute postoperative pain (NRS 0-10), time frame up to 24h postoperatively 2. Nausea and vomiting Secondary outcome: 1. Change in minimental state evaluation test, time frame pre-op, 1h post-op, at discharge 2. Severe postoperative adverse effect related to anesthesia (postoperative hypoxemia, ileus, postoperative cognitive dysfunction)