2021, Vol. 3, Issue 2, Part I

Aim: To compare 3 different Dexmedetomidine Doses and Their Effect on the Duration of Spinal Anesthesia.

Methods: Any gender between 18 and 65 years with American Society of Anesthesia physical state I or II (ASA I or II) with body mass index (BMI) 40 kg/m2 or below were included in this study. All patients that were included were randomized, using computer generated random number table, to four groups: control group (group C) and three experimental groups (groups D1.5, D3 and D5). At the site of local anesthesia, a spinal needle 25G was advanced till reaching the intrathecal space and cerebrospinal fluid (CSF) flows through the needle, and then the following were injected according to the groups: Total 100 Patients were included in this study 25 in each group. Group C: 3 mL (15 mg) of 0.5% levobupivacaine+0.5 mL normal saline. Group D1.5: 3 mL (15 mg) of 0.5% levobupivacaine+0.5 mL (1.5 μg) Dexmedetomidine. Group D3: 3 mL (15 mg) of 0.5% levobupivacaine+0.5 mL (3 μg) Dexmedetomidine. Group D5: 3 mL (15 mg) of 0.5% levobupivacaine+0.5 mL (5 μg) Dexmedetomidine. Dexmedetomidine was prepared by dilution on saline to reach the needed dose under complete sterile precautions. For instance; 0.3 ml of Dexmedetomidine with 30 μg was diluted on 100 ml saline to become 3 μg/ml to achieve 1.5 μg per 0.5 ml.

Results: Regarding the onset of the sensory block, there were statistical differences among groups as group C showed onset after 1.7 ± 1.7 min while group D1.5 showed onset of sensory block after 2.5 ± 1.88 min while in group D3 it was 3.12 ± 2.54 min and in group D5 it was 2.63 ± 3.34 min. The previous results showed a dose-response prolongation to the Dexmedetomidine; this prolongation shows a statistically significant between the control group C and the other three groups (p-value 0.001). On the other hand, there were no statistical differences among the study groups (p-value 0.57). Moreover, this prolongation has no clinical significance. Regarding the duration of the sensory block there is, again, a dose- related prolongation with a crescendo pattern (group C 217.21 ± 81.69 min), group D1.5 (221.22 ± 50 min), group D3 (303.56± 43.01 min), group D5 (367.75 ± 97.68 min)). However, there was no statistical significance between the control group and group D1.5 (p-value was 0.24). On the contrary, there was a prolongation in both groups D3 and D5 which have achieved a statistical significance (p value was<0.001) in comparison with the control group. The same pattern was achieved in the duration of the motor block as it was (207.25 ± 45.26min) in group C, (250.27 ± 82.69 min) in group D1.5, (269.67 ± 33.61 min) in group D3 and (320.64 ± 93.12 min) in group D5. The above results showed a statistical difference with significance between groups D5 and D3 on one hand and control group C on the other hand with p-value 0.004. Likewise, there was no statistical significance between both groups C and D1.5 with p-value 0.57 and even more among any experimental groups (D1.5, D3 and D 5 vs. each other).

Conclusion: We concluded that Dexmedetomidine can prolong the duration of the spinal anesthesia with a high safety profile and no complications in both doses 3 and 5 μg but not with a dose of 1.5 μg.