Pregabalin Effects on Hypotensive Anesthesia During Spine Surgery.
Condition: Spine Surgery
Study type: Interventional

Summary: 
      Elective lumbar spine surgical procedures are commonly performed under controlled hypotension
      during general anesthesia. That is beneficial to limit the intraoperative blood loss and
      transfusions and improves surgical field. Deliberate hypotension could be achieved via
      various medications but mostly associated with significant side effects. Pregabalin
      effectively augmented hypotensive anesthesia. The hypothesis is that Pregabalin 150 mg single
      preoperative dose may augment intraoperative deliberate hypotension that will be reflected on
      blood loss and nitroglycerin consumption.
    

Detailed description: 
      An arterial line will be established then general anesthesia will be conducted. After
      adequate preoxygenation, anesthesia induction by IV fentanyl 1.5µg/kg, propofol 2 mg/kg, and
      atracurium 0.5 mg/kg then appropriated size tracheal tube. The ventilator settings will be
      adjusted to maintain the end-tidal carbon dioxide tension (ETco2) at 30-35 mm Hg. Anesthesia
      will be maintained by isoflurane concentration 1.2%, with 40% oxygen in air then IV infusion
      of fentanyl 0.05 mcg/kg/min was started while atracurium 0.1 mg/kg incremental dose as
      required. Then patients will be turned into the prone position above pad support permitting
      free hanging of the abdomen. Intraoperatively, the target mean arterial arterial blood
      pressure (MBP) is 55-65 mm Hg. After surgical incision, if MBP exceeds 65 mm Hg (defined as
      hypertension) it will be managed by: increasing isoflurane MAC up to 2%, if no response after
      5 min, Nitroglycerin infusion initiated at 0.5 mcg/kg/min to 40 mcg/kg/min. Hypotension (MBP
      <55 mm Hg) will be treated by stopping nitroglycerin, proper compensation of losses, reducing
      Isoflurane MAC. If persisted; vasoactive drugs will be used. Bradycardia (HR <50 beat/min.),
      treated with 0.01 mg/kg atropine IV increments.

      The nitroglycerin infusion will be stopped after the finial surgical hemostasis. Fentanyl
      infusion will be stopped before ligament sutures. Isoflurane will be closed after the last
      surgical suture. After dressing, patient will be turned to the supine position and morphine
      0.025 mg/kg IV will be administered then 0.04 mg/kg neostigmine and 0.015 mg/kg atropine for
      reversal. Extubation will be done after establishment of acceptable spontaneous respiration.
    

Intervention name(s): Pregabalin; placebo
Intervention type(s): Drug; Drug
Intervention description(s): Pregabalin 150 mg capsule, one h preinduction of general anesthesia; given a placebo identical capsule once one hour before anesthesia
Other intervention name(s): (LYRICA® 150 mg capsule- PFIZER); control
Intervention MeSH terms: Pregabalin
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Supportive Care
Keywords: Pregabalin, hypotensive anesthesia, blood loss, analgesia