الفهرس 
Introduction.Only 14 pages are availabe for public view
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Abstract
This study was done aiming at comparing the peri-operative effects of
dexmedetomidine and fentanyl in patients scheduled for lumbar discectomy with
TIVA. The hemodynamics, the rate difference of propofol consumption, the analgesic
requirements and the postoperative recovery charachteristics were compared.
Fifty patients undergoing single level posterior approach lumbar discectomy were
allocated into two groups; D and F.
Patients in Group D received dexmedetomidine 0.6 μg/kg IV over 10 minutes and
patients in Group F received fentanyl 1 μg/kg IV as loading doses before induction.
After pre-oxygenation, anesthesia was induced with 20 mg of propofol boluses
given until the BIS became less than 60. After loss of consciousness and adequate
manual ventilation, Cisatracurium at a dose of 0.15 mg/kg was used to facilitate
tracheal intubation. After orotracheal intubation, the lungs were ventilated. All
patients were placed in a prone position on a standard operating frame.
Anesthesia was maintained with air/oxygen mixture (1:1), controlled ventilation
and propofol infusion (50-150 μg/kg/min). The TOF was assessed every 10 minutes.
Cisatracurium (0.03mg/kg) was administered when the TOF count becomes ≥2.
Dexmedetomidine infusion was maintained at a dose of 0.2 μg/kg/h for group (D)
and fentanyl infusion was maintained at a dosage of 0.5 μg/kg/h for group (F).
Dexmedetomidine and fentanyl infusions were increased by 0.1 μg/kg/h according to
the hemodynamics. The infusions of dexmedetomidine and fentnayl were adjusted to
keep the mean arterial blood pressure not <20 % nor >10 % from the preoperative
baseline value.
End tidal CO2 of 35-40 mmHg was maintained. BIS range between 40 and 60 was
considered adequate for hypnotic state. Absence of the 4th, 3rd and 2nd twitches of the
TOF was the targeted degree of muscle relaxation.
Summary
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The Fentanyl infusion was terminated at the end of discectomy and the
dexmedetomidine infusion was terminated at the beginning of skin closure.
Paracetamol at a dose of 15 mg/kg IV was given at the start of skin closure for both
groups. Propofol was discontinued towards the end of the case with the goal of
achieving a quick recovery without allowing BIS values over 60 before the dressing
is applied.
Neostigmine (0.05 mg/kg) and atropine (0.02 mg/kg) were administered to
antagonize residual neuromuscular block at the end of the procedure. The patient was
extubated at a T4/T1 of 0.75 and BIS of 90-100.
After the operation, the patient was transferred to the recovery room and the
consciousness score was evaluated every 5 min using the modified Aldrete score
(respiration, O2 saturation, motor activity, consciousness and blood pressure) until
ready for discharge.
The propofol induction and maintenance doses were significantly lower in group D
than group F. Cisatracurium consumption was insignificantly lower in group D than
group F.
The MAP after induction was significantly lower in group D than group F. Both
dexmedetomidine and fentanyl effectively abolished the stress response to
laryngoscopy and intubation. The maintenance doses of dexmedetomidine and
fentanyl were increased to 0.3 μg/kg/hr and 0.2 μg/kg/hr respectively to counteract
the stress response to surgical skin incision. No rebound increase in MAP was noted
after dexmedetomidine discontinuation.
All over the perioperative period, the HR was lower in group D than group F. A
single case in group D developed bradycardia after induction of anesthesia. The
patient’s HR increased spontaneously to 63 beat/minute after intubation, so it didn’t
necessitate any interference hence the stress of intubation was enough.
At the end of anesthesia, extubation time was slightly longer in group F than in
Summary
107
group D however to a statistically insignificant extent. PACU discharge time was
slightly prolonged however to a statistically insignificant extent in group D than
group F.
Patients in group D required supplemental analgesia significantly earlier than those
of group F.
The incidence of nausea was significantly lower in group D than in group F. The
incidence of vomiting was lower in group D than group F however to a statistically
insignificant extent. The incidence of shivering and respiratory depression was lower
in group D than group F however to a statistically insignificant extent. The incidence
of bradycardia and dry mouth was higher in group D than group F however to a
statistically insignificant extent.