The Effect of Intraoperative Ketamine on Opioid Consumption and Pain After Spine Surgery in Opioid-dependent Patients
Condition: Postoperative Pain; Chronic Pain; Analgesics
MeSH terms: Chronic Pain; Pain, Postoperative
Study type: Interventional
Phase: Phase 4

Summary: 
      Patients with a daily use of opioids may develop higher postoperative pain levels, often need
      high doses of morphine and therefore their pain may be difficult to treat. A low dose of an
      old anesthetic drug, ketamine, administered during surgery can possibly reduce pain and
      morphine consumption in these patients. Our purpose is to investigate the effect of low dose
      ketamine on morphine consumption and pain after spine surgery in patients with a daily use of
      opioids. Our hypothesis is that low dose ketamine can reduce morphine consumption, pain and
      side-effects after spine surgery.
    

Detailed description: 
      Opioid-dependent patients can develop hyperalgesia and often have a high opioid consumption
      postoperatively due to opioid tolerance. Intraoperative ketamine in subanesthetic doses can
      possibly reduce hyperalgesia and reduce opioid-tolerance in these patients. Ketamine is a
      non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist that works by blocking the
      NMDA receptors in the central and peripheral nerve system. It can be used for general
      anesthesia but the drug also has other properties including lowering of central excitability
      and reducing postoperative opioid tolerance by modeling the opioid receptors. Further more it
      can possibly reduce chronic pain by blocking wind-up effect when blocking the NMDA receptors.

      Our purpose is to investigate the effect of intraoperative ketamine on opioid consumption and
      pain after spine surgery in opioid-dependent patients. Our hypothesis is that ketamine can
      reduce opioid consumption and reduce postoperative pain and side effects compared to placebo.
    

Intervention name(s): (S)-(+)-Ketamine Hydrochloride Solution 25 mg/ml; Isotonic sodium chloride 0.9 percent; Paracetamol 1 g; Morphine Sulphate 1 mg/ml; Morphine Sulphate 1 mg/ml; Ondansetron 2 mg/ml; Usual daily opioids; Morphine Sulphate 1 mg/ml; Sufentanil 5 microgram/ml
Intervention type(s): Drug; Drug; Drug; Drug; Drug; Drug; Drug; Drug; Drug
Intervention description(s): Ketamine (25 mg/ml) bolus 0.5 mg/kg administered immediately after induction of anesthesia, followed by infusion ketamine 0,25 mg/kg/hour that is terminated when the last suture to the skin has been performed.; Isotonic sodium chloride 0.9 percent 0.02 ml/kg administered immediately after induction of anesthesia, followed by infusion isotonic sodium chloride 0.01 ml/kg/hour that is terminated when the last suture to the skin has been performed.; Paracetamol 1 g orally 1 hour preoperatively and every 6 hours after extubation time during the first 24 hours.; Morphine Sulphate 1 mg/ml administered as patient-controlled analgesia (PCA, bolus 2.5 mg, lockout 5 minutes) 0-24 hours postoperatively; Morphine Sulphate 1 mg/ml, bolus 2.5 mg administered by the PACU nurse on request of the patient for the first hour postoperatively.; Ondansetron 2 mg/ml 4 mg iv in case of moderate to severe nausea, supplemented by Ondansetron 1 mg iv if needed; The patients usual daily opioid consumption are administered during the study period; Morphine Sulphate 1 mg/ml, bolus 0.4 mg/kg administered 45 minutes before expected awakening.; Sufentanil 5 microgram/ml, bolus 5 micrograms administered by the anaesthetic nurse in the operating room if the patient is in pain upon awakening.
Other intervention name(s): Ketamine; Isotonic saline; Paracetamol; Morphine; Morphine; Zofran; Morphine; Morphine; Sufentanil
Intervention MeSH terms: Acetaminophen; Sufentanil; Ketamine; Morphine; Dsuvia; Ondansetron
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Morphine consumption; Postoperative pain; Ketamine; Side effects; Spine surgery; Chronic pain