Dexmedetomidine as an Additive to Spinal Anaesthesia in Orthopaedic Patients Undergoing Lower Limb Surgeries: A Randomized Clinical Trial Comparing Two Different Doses of Dexmedetomidine

A Comparison of Subarachnoid Block Characteristics Following Co-administration of Fentanyl Premixed With Hyperbaric Bupivacaine Versus Antecedent or Succedent to Hyperbaric Bupivacaine: A Randomized Controlled Study

Background Adjuvants are often used during subarachnoid block to enhance and prolong the analgesia and decrease the adverse effects of high doses of local anesthetic agents. Intrathecal fentanyl premixed with hyperbaric bupivacaine has been used in spinal anesthesia and compared with the sequential use of these drugs in separate syringes. However, given the paucity of literature, we conducted this study where premixed antecedent and succedent administration of intrathecal fentanyl with hyperbaric bupivacaine were compared in terms of flow dynamics, block characteristics, and hemodynamic alterations. Methodology This prospective, randomized, triple-blinded comparative study was conducted among 160 patients who were randomly allocated into four groups. Group A (n = 40) (control) received 3.0 mL (15 mg) of 0.5% hyperbaric bupivacaine and 0.5 mL of normal saline via a 5.0 mL syringe. Group B (n = 40) received 3.0 mL (15 mg) of 0.5% hyperbaric bupivacaine and 0.5 mL (25 µg) of fentanyl premixed via a single 5.0 mL syringe. Group C (n = 40) received 0.5 mL (25 µg) of fentanyl via a 1.0 mL syringe followed by 3.0 mL (15 mg) of 0.5% hyperbaric bupivacaine via a 5.0 mL syringe. Group D (n = 40) received 3.0 mL (15 mg) of 0.5% hyperbaric bupivacaine via a 5.0 mL syringe followed by 0.5 mL (25 µg) of fentanyl via a 1.0 mL syringe. The onset and regression of sensory and motor blockade, hemodynamic parameters, time to first rescue analgesia, and adverse events were observed. Data analysis was done using SPSS version 17.0 (SPSS Statistics Inc., Chicago, IL, USA). Results The mean time taken for the onset of sensory and motor blockade was least in Group D followed by Group C. Duration of sensory and motor blockade was prolonged in Group D. Patients in Group A experienced more hypotension than Groups B, C, and D. Requirement of rescue analgesia was delayed in Groups C and D. Conclusions Administering 25 µg (0.5 mL) of Fentanyl separately after 15 mg (3.0 mL) of 0.5% hyperbaric bupivacaine results in early onset and prolonged duration of sensory and motor blockade, intraoperative hemodynamic stability, the delayed requirement of rescue analgesia postoperatively, and fewer side effects compared to its co-administration as a premixed solution or antecedent to hyperbaric bupivacaine.

Intrathecal Dexmedetomidine Combined With Ropivacaine in Cesarean Section: A Prospective Randomized Double-Blind Controlled Study

Objective

This study aimed to find the best dose of dexmedetomidine in spinal anesthesia for cesarean section.

Methods

120 American Society of Anesthesiologists (ASA) Class I and II parturients undergoing elective cesarean delivery under spinal anesthesia were randomly allocated into four groups treated with intrathecal ropivacaine (12 mg) alone (Group R) or in combination with dexmedetomidine 5 μg (Group RD1), 7.5 μg (Group RD2) and 10 μg (Group RD3). Characteristics of spinal anesthesia, hemodynamic changes, adverse effects, stress reactions and neonatal outcomes were recorded in the four groups.

Results

Patients in Group RD1, RD2, and RD3 had significantly longer sustained sensory and motor block time than patients in Group R. All four groups had comparable onset times of sensory and motor block. The time for the level of sensory block to lower to S1 was longer in Group RD1 (411.07 ± 106.66 min), Group RD2 (397.03 ± 125.39 min) and Group RD3 (468.63 ± 116.43 min) than in Group R (273.60 ± 88.34 min) (p < 0.001). The time to recover from motor block to a Bromage score of IV was longer in Group RD1 (353.60.07 ± 137.28 min), Group RD2 (350.57 ± 118.01 min) and Group RD3 (404.67 ± 112.83 min) than in Group R (232.70 ± 93.29) (p < 0.01). The incidence of chills was significantly lower in the Group RD1, RD2, and RD3 than in the Group R (p < 0.001). There was no significant difference in the incidence of adverse effects such as hypotension, bradycardia, nausea, vomiting, hypoxemia and pruritus in the four groups (p > 0.05). There was no statistically significant visceral traction response or fentanyl use in the four groups (p > 0.05). Phenylephrine dosing was significantly higher in Group RD2 and RD3 than in Group R (p < 0.05), and there was no significant difference in phenylephrine dosing between Group RD1 and Group R (p > 0.05). There were no statistical differences in postnatal Apgar scores (1 min, 5 min after birth) (p > 0.05). The postoperative concentrations of β-endorphin (β-EP), cortisol (Cor) and tumor necrosis factor-α (TNF-α) in the Group RD1, RD2, and RD3 were lower than that in Group R (p < 0.05).

Conclusion

Intrathecal 5μg of dexmedetomidine as an adjuvant to ropivacaine relieved intraoperative chills, did not increase intraoperative and postoperative adverse effects, did not increase the amount of intraoperative vasoconstrictor used, and reduced intraoperative stress reactions as well as prolonged the duration of maternal sensory and motor block, so this dose is appropriate for cesarean section.

Clinical Trial Registration

[www.chictr.org.cn/], identifier [ChiCTR2200056052].

Efficacy of premixed versus succedent administration of fentanyl and bupivacaine in subarachnoid block for lower limb surgeries: A randomised control trial

Background and Aims

Subarachnoid block is the most commonly used anaesthesia technique for lower limb surgeries. Opioids are the most commonly used adjuvants with local anesthetics (LA). Adjuvants are given premixed with LA loaded in a single syringe. This study was conducted to evaluate differences in level of sensory and motor block and incidence of hypotension whilst administering hyperbaric bupivacaine and fentanyl either in a single syringe or different syringes. The effect of administering opioid prior to LA and vice versa on these parameters was also assessed.

Methods

One hundred and twenty patients were randomly allocated into three groups of 40 each: Group A received premixed 0.5% heavy bupivacaine 2.5 ml (12.5 mg) and 0.5 ml (25 microgram) of fentanyl in a single 3.0 ml syringe, Group B received 0.5 ml (25 microgram) of fentanyl in a 3.0 ml syringe followed by 0.5% heavy bupivacaine 2.5 ml (12.5 mg) in a 3.0 ml syringe, Group C received 0.5% heavy bupivacaine 2.5 ml (12.5 mg) in a 3.0 ml syringe followed by 0.5 ml (25 microgram) fentanyl in a 3.0 ml syringe. All statistical calculations were done using SPSS 21 version statistical program for Microsoft Windows.

Results

The mean time for onset of sensory and motor block was least in group C followed by group B. The duration of sensory and motor block was prolonged in groups B and C. Patients in group A experienced more hypotension as compared to groups B and C.

Conclusion

Administering hyperbaric bupivacaine first followed by fentanyl leads to an early onset and prolonged duration of sensory and motor block.