Dexmedetomidine group (Group D)
Bradycardia, restless, Hypotension, pain
SECONDARY
Epidural bolus dose of 12 ml (10 ml 0.25% bupivacaine plus 100 µg dexmedetomidine (Precedex™, Dexmedetomidine HCl 100 µg/mL, Pfizer Inc.) in 2 ml volume, top-up dose of 8 ml (6 ml 0.25% bupivacaine plus 20 µg dexmedetomidine in 2 ml volume) [The level of sensory block was checked (for spinal then for epidural) by pinpricking with a 24G hypodermic needle at T10 dermatome midclavicular line using a 3-point scale: 0 = normal sensation, 1 = loss of sensation of pin prick (analgesia), 2 = loss of sensation of touch (anesthesia) [The onset of sensory blockade injected intrathecally with maximal cephalic spread was assessed every 5 min for 30 min and then every 30 min. When sensory block regressed to T10 dermatome, epidural bolus dose was given according to each group. The onset, maximum level of sensory blockade and duration of epidural analgesia were recorded. The duration of analgesia from the time of epidural injection until VAS score ≥ 3 was recorded.Monitoring of the patient’s vital signs (HR, MAP, and peripheral oxygen saturation) was recorded every 5 min for the first 30 min, after epidural bolus injection, and then every 30 min until the end of the operation. Hypotension (fall in mean blood pressure > 20% of baseline) treated by volume expansion or by incremental doses of IV ephedrine 3–6 mg. Bradycardia (heart rate < 60/min) was treated by 0.6 mg IV atropine.Ramsey sedation score was used to assess the patient’s level of sedation (0–6) [1 = Patient is anxious and agitated or restless, or both.2 = Patient is cooperative, oriented, and tranquil.3 = Patient responds to commands only.4 = Patient exhibits brisk response to light glabellar tap or loud auditory stimulus.5 = Patient exhibits a sluggish response to light glabellar tap or loud auditory stimulus.6 = Patient exhibits no response.The sedation score was recorded just before the initiation of epidural injection and 2 h postoperatively.Postoperatively, patients were evaluated for pain every 2 h until 8 h and then every 4 h until 24 h. If VAS ≥ 3, injection of the top-up dose in the epidural catheter was performed according to each group, number and total doses were recorded. If pain persisted after 3 top-up doses with time interval of 30 min, ketorolac 30 mg IM was given, the timing and total dose required in the first 24 h were recorded. Patients completed 120 min after bolus injection in post anesthesia care unit (PACU) for monitoring and recording of any side effects postoperatively. 5-points Likert scale was used to evaluate patient satisfaction 24 h postoperatively, where 1 = very non satisfied, 2 = dissatisfied, 3 = neutral, 4 = satisfied, and 5 = highly satisfied.The primary outcome of our study was the duration of postoperative analgesia defined by the time from epidural bolus injection till VAS ≥ 3 and secondary outcomes included the occurrence of any side effects related to the study drugs and patient satisfaction score.