Dexmedetomidine in Thoracoscopic Surgery: Opioid-Sparing Strategy
Condition: Opioid Use; Postoperative Pain
MeSH terms: Pain, Postoperative
Study type: Interventional

Summary: 
      Numerous studies in recent years have shown that the use of opioid-free analgesia can reduce
      opioid use and length of stay in the recovery room, as published in the journals Anesthesia &
      Analgesia1. Compared with traditional opioid analgesic anesthesia, opioid-free analgesic
      anesthesia can be used to reduce postoperative respiratory complications, postoperative
      nausea and vomiting, and postoperative opioid needs. During surgery, opioid analgesics may
      have immunosuppressive effects, but different anesthesia/analgesia methods will change the
      individual's stress response, affect the human body's cellular immunity, and may even lead to
      changes in angiogenesis growth factors associated with cancer recurrence, so it is likely to
      affect the prognosis of cancer patients. In addition, Dexmedetomidine, a highly selective
      alpha-2 adrenergic receptor agonist, can replace opioids for pain relief during surgery,
      providing superior analgesia and reducing opioid use while reducing the need for general
      anesthetics amount, thus avoiding suppression of immune system function. A study in the
      Journal of Anaesthesiology Clinical Pharmacology pointed out that Dexmedetomidine can be used
      to replace opioid analgesics in surgical anesthesia, and there was no difference in the use
      of rescue opioid analgesics during and after surgery5. Several clinical studies have shown
      that opioid-free anesthesia is significantly associated with a lower incidence of respiratory
      complications and postoperative nausea and vomiting. Therefore, general anesthesia combined
      with Dexmedetomidine can be regarded as an opioid-free anesthesia strategy.
    

Detailed description: 
      Study protocol

      All patients received target-controlled infusion (TCI) propofol (3-5 μg ml-1), 2% lidocaine
      1.5 mg kg-1 and cisatracurium (0.15-0.2 mg kg-1) or rocuronium (0.6-1.0 mg kg-1).

      During induction, the dexmedetomidine group received a loading dose of 0.5 µg kg-1 of
      dexmedetomidine for 10 minutes. Meanwhile, propofol TCI was started with target of bispectral
      index set between 40 and 60. After the loading dose was complete, tracheal intubation was
      performed without opioid analgesic. The following maintenance dose was set as 0.5 µg kg-1 h-1
      until the specimen was excised and two-lung ventilation was performed. Dexmedetomidine was
      then stopped. In contrast, the conventional control group was administered an intermittent
      bolus dose of fentanyl (0.3-0.5 µg kg-1) to reduce stimuli before tracheal intubation.

      In the maintenance phase, parecoxib (40 mg) or propacetamol (1 g) was given if indicated.
      Anaesthesia was maintained with TCI propofol, and the depth of anaesthesia was monitored
      using a bispectral index between 40 and 60. Fentanyl was used as a rescue analgesic during
      the operation. In both groups, when the patient's HR or mean arterial pressure (MAP) was >25%
      of the baseline, an intermittent bolus dose of 15-25 µg fentanyl was administered. At the end
      of surgery, patients received intercostal nerve block under thoracoscopy by surgeon.

      Haemodynamic stabilisation was achieved in the following situations. If analgesic was
      administered but the MAP remained elevated at >25% of baseline, nicardipine was considered.
      If hypotension with MAP dropped >25% from baseline, ephedrine was considered. If bradycardia
      with HR dropped to <50, atropine was considered.

      Pain intensity was assessed in the post-anaesthesia care unit (PACU) using a numerical rating
      scale (NRS) ranging from 0 to 10 every 15 minutes until 1 hour after surgery. The goal NRS
      score was <3. If the severity was higher than 3, an intermittent bolus of fentanyl was used.
      Furthermore, we recorded postoperative complications including nausea, vomiting and
      respiratory compromise. On the following day, we visited the patient to record complications,
      severity of postoperative pain and analgesia use in the general ward.
    

Intervention name(s): Dexmedetomidine
Intervention type(s): Drug
Intervention description(s): Initially give loading dose with 0.5 mcg/kg for 10 min and then keep maintenance dose with 0.5 mcg/kg/h until two-lung ventilation.
Intervention MeSH terms: Dexmedetomidine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: Dexmedetomidine; Opioid-free anesthesia; Non-small Cell Lung Cancer