Comparative Study Between Two Adjuvant Drugs to Bupivacaine for Post-operative Epidural Analgesia in Abdominal Surgeries

Comparative Study Between Two Adjuvant Drugs to Bupivacaine for Post-operative Epidural Analgesia in Abdominal Surgeries

Comparative Study Between Dexmedetomidine and Fentanyl as Adjuvants to Bupivacaine for Post-operative Epidural Analgesia in Abdominal Surgeries

Epidural analgesia is associated with early postoperative mobilization and rehabilitation with minimally associated pain and discomfort. Analgesic effect of local anesthetics is augmented by addition of adjuvants in epidural anesthesia ensuring satisfactory postoperative period. This study evaluates the effect of dexmedetomidine and fentanyl as additives to bupivacaine for epidural analgesia.

The aim of the study is to evaluate the effect of dexmedetomidin and fentanyl as adjuvants to bupivacaine for postoperative epidural analgesia in abdominal surgeries regarding block characteristics, post-operative analgesia, hemodynamic changes and any anticipated side effects. Type of Study: Prospective randomized comparative clinical study. Study Setting: The operating theatres of Ain Shams University Hospitals Study Period: One year Sampling Method: Random sampling Patients randomly allocated by computer generated randomization and using opaque sealed envelopes to one of the three study groups according to the adjuvant drug used in postoperative analgesia. Sample Size: Total 75 cases divided into 25 cases in each group. Kiran et al. (2018) reported a rather large effect size comparing onset to sensory block and time to maximum motor block. In a one-way ANOVA study, sample sizes of 25 cases per group in three groups whose means are to be compared. The total sample of 75 subjects achieves 80% power to detect differences among the means versus the alternative of equal means using an F test with a 0.0500 significance level. The size of the variation in the means is represented by the effect size = 0.4

Normal saline 2 ml will be mixed with 48 ml bupivacaine 0.125% in an elastomeric pump. The rate of epidural infusion will be 5ml/hr for the postoperative 24 hours.

Fentanyl 2 ml (100 μg) will be mixed with 48 ml bupivacaine 0.125% in an elastomeric pump. The rate of epidural infusion will be 5ml/hr for the postoperative 24 hours.

Dexmedetomidine 1 ml (100 μg) plus 1 ml normal saline will be mixed with 48 ml bupivacaine 0.125% in an elastomeric pump. The rate of epidural infusion will be 5ml/hr for the postoperative 24 hours.

will be assessed by pin prick and cold application from the start of epidural infusion till scoring 1 at the 3 point scale. Assessment will be done every 5 minutes until the onset of sensory block using a 3-point scale: 0=normal sensation, 1=loss of sensation of pin prick (analgesia), and 2=loss of sensation of touch (anesthesia).

for 24 hours using the Visual Analogue Scale ranging from 0 to 10 (0 - no pain, 10 - worst pain ever) at 0, 2, 6, 12 and 24 hrs after starting epidural infusion.

will be assessed if occurred by Bromage three point score (0-3) for the lower extremity during the 24 hours following epidural infusion where 0: no motor impairment (able to move the hip, knee, and ankle joints); unable to raise either extended leg (able to move joints of knee and ankle); unable to raise extended leg and flex knee (able to move joint of ankle); 3; unable to move knee and foot.

Mean arterial pressure in mmHg will be monitored continuously and recorded just before the initiation of epidural infusion and thereafter at 2, 6, 12 and 24 hrs. postoperatively during the 24 hours following epidural infusion

Heart rate (HR) in beats per minute (bpm) will be monitored continuously and recorded just before the initiation of epidural infusion and thereafter at 2, 6, 12 and 24 hrs. postoperatively during the 24 hours following epidural infusion

Peripheral oxygen saturation in blood (SpO2) will be monitored continuously and recorded just before the initiation of epidural infusion and thereafter at 2, 6, 12 and 24 hrs. postoperatively during the 24 hours following epidural infusion

Inclusion Criteria: ASA I or ASA II patients. Age group: 21-70 years old. BMI ≤40 Duration of procedure ≤ 180 minutes. Exclusion Criteria: Patients with known neurologic and psychiatric illness will be excluded from the study. Contraindications for epidural anesthesia as patient refusal, bleeding or coagulation test abnormalities, local skin infection at spinal lumbar region, raised intracranial pressure and hypovolemia Spine abnormalities. Systemic disorders like hematological, respiratory, cardiac, renal or hepatic insufficiency. Allergy to any of the drugs used in the study.

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