Spine Surgery
Conditions
Keywords
Pregabalin, hypotensive anesthesia, blood loss, analgesia
Brief 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.
Interventions
DRUGPregabalin
Pregabalin 150 mg capsule, one h preinduction of general anesthesia
DRUGplacebo
given a placebo identical capsule once one hour before anesthesia
Sponsors
Mansoura University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
No
Inclusion criteria
* American Society of Anesthesiologists (ASA) score I-II * admitted to undergo lumbar discectomy or spinal fixation surgery under general anesthesia
Exclusion criteria
* Patients on anti-hypertensive treatment, diuretics, corticosteroids, pregabalin, gabapentin, anticonvulsants, antipsychotics, * alcohol addiction or drug abuse * patients with history of allergy to any drug used in the study . * pregnant or nursing women * patients with peripheral neuropathy, endocrinal diseases, bleeding abnormality, * cardiac, hepatic or renal impairment
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Nitroglycerin consumption | Intraoperative | the total nitroglycerin consumption in milligram to maintain the target mean arterial pressure (MAP) 55- 65 mmHg. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The number of transfused blood unites | intraoperative | Packed red blood cell unites |
| heart rate (HR) | Basal, during intubation, then at 1, 5, 30, 60, 90, 120, 150, 180, 210 minutes post extubation, then postoperatively at 1 and 2 hours. | in beat/min |
| end-tidal isoflurane concentration | at 30, 60, 90, 120, 150 , 180, 210 minutes after intubation. | in percent |
| Surgeon satisfaction about the field | within 2 hours from the end of surgery. | using a six-point scale (0 = no bleeding, virtually bloodless field; 5 = uncontrolled) bleeding). |
| Sedation | at 0, 2, 4, 6, 12, 24 hours postoperatively | (Ramsay sedation scale) |
| Estimated blood loss | intraoperative | towels are weighted, plus suction volume without irrigation fluids in milliter. |
| Postoperative pain | at 0, 2, 4, 6, 12, 24 hours postoperatively. | (VAS 0-10 scale) 10 is the worst pain |
| The total morphine consumption | in the 1st 24 hours postoperatively | in mg |
| Frequency of adverse effects | during the first 24 hours postoperatively | dizziness, headache, nausea and vomiting, or pruritus. |
| Peak airway pressures | 10 minutes after settled prone position | in centimeter water |
| invasive mean arterial blood pressure (MAP) | Basal, during intubation, then at 1, 5, 30, 60, 90, 120, 150, 180, 210 minutes post extubation, then postoperatively at 1 and 2 hours. | in millimeter mercury (mmHg) |
| The time to the first request of analgesia. | 24 hours postoperative | in hours |
Countries
Egypt
Outcome results
None listed