Subarachnoid Block Characteristics Research Articles

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.

Efficacy of dexmedetomidine and magnesium sulphate as adjuvant to bupivacaine among patients undergoing lower extremity surgeries

In this prospective randomised double blind study, an attempt was made to compare the effects of adding dexmedetomidine 10 mcg or magnesium sulphate 50mg to 0.5% hyperbaric bupivacaine on subarachnoid block characteristics and postoperative analgesia in patients undergoing elective lower extremity surgeries. Randomization of the participants was done in three equal groups (n=30). A total of 90 patients of age between 18-60 years of either sex and good physical status posted for elective lower extremity surgery were included. Group B received 15 mg hyperbaric bupivacaine(3ml) with 0.5ml preservative free normal saline,Group D received 15 mg hyperbaric bupivacaine (3ml) with 10 mcg dexmedetomidine in 0.5 ml preservative free normal saline intrathecally and Group M received 15 mg hyperbaric bupivacaine (3ml) with 50mg magnesium sulphate (0.5ml) intrathecally for subarachnoid block. Different parameters of sensory block, motor block and analgesia effect were assessed as outcomes. Results showed that the groups were similar in demographic parameters like age, sex, height, weight, physical status. Bupivacaine with dexmedetomidine as adjuvant shows early onset of sensory and motor block, early onset of peak block height, prolonged sensory block, prolonged two segment regression time.

Effect of intrathecal clonidine on subarachnoid block characteristics in patients undergoing TURP and TURBT

Effect of intrathecal clonidine on subarachnoid block characteristics in patients undergoing TURP and TURBT

Effect of 3 Different Doses of Intrathecal Dexmedetomidine (2.5µg, 5µg, and 10 µg) on Subarachnoid Block Characteristics: A Prospective Randomized Double Blind DoseResponse Trial

Background: The extended analgesic efficacy of intrathecal dexmedetomidine (ITD) has been investigated in a few clinical trials; however, there is a lack of conclusive evidence upon its ideal dosage. Objectives: To elucidate the dose-response relationship between ITD and subarachnoid block characteristics, particularly the duration of analgesia and differential analgesia (DA: defined as time difference from the offset of motor blockade to the first analgesic requirement on numerical rating scale ≥ 4.0). Study Design: Prospective, randomized double blind active control trial. Setting: Medical college teaching hospital. Methods: Ninety adult (18 – 60 years) patients undergoing elective lower abdominal and lower limb surgeries were randomized into 3 groups to receive intrathecal 0.5% bupivacaine 3 mL with 2.5 µg (group BD2.5), 5µg (group BD5), or 10 µg (group BD10) dexmedetomidine in 0.5 mL normal saline. The 2 segment sensory regression times (TSSRT), duration of motor blockade analgesia, DA, and perioperative adverse effects were assessed. The primary outcome was duration of analgesia and DA. Statistics: ANOVA, Kruskal Wallis test, Chi-square (χ2), and Fisher’s exact test, significance: P < 0.05. Results: The onset of sensory block was significantly earlier in group BD10 compared with group BD5 (P = 0.035) and BD2.5 (P = 0.010) while the onset of motor block was significantly earlier in group BD10 compared with BD2.5 (P = 0.020). There was a significant and dose-dependent prolongation of the duration of sensory block (127.50, 149.17, and 187.50 minutes; P < 0.001), motor block (258.50, 331, and 365 minutes; P < 0.001), analgesia (306.17, 396.50, and 512 minutes; P < 0.001), and DA (47.67, 65.50, and147 minutes; P < 0.001) with escalating doses of ITD, respectively. Group BD10 required significantly fewer rescue analgesics compared with other 2 groups (P = 0.001). Except for mild sedation which was significantly higher in group BD10; all the groups were comparable with respect to hemodynamic and other adverse effects. Limitations: Lack of placebo group, exclusion of higher doses (15µg) of ITD, and short duration of postoperative follow-up. Conclusions: The addition of 10 µg compared with 2.5 µg or 5µg ITD to 0.5% hyperbaric bupivacaine is associated with significantly earlier onset of sensory and motor block as well as prolonged duration of sensory block, motor block, analgesia, and DA with a comparable adverse effect profile. Key words: Analgesia, bupivacaine, dexmedetomidine, differential analgesia, intrathecal, pain, spinal anaesthesia

Efficacy of intrathecal midazolam in potentiating the analgesic effect of intrathecal fentanyl in patients undergoing lower limb surgery.

Introduction:The intrathecal administration of combination of drugs has a synergistic effect on the subarachnoid block characteristics. This study was designed to study the efficacy of intrathecal midazolam in potentiating the analgesic duration of fentanyl along with prolonged sensorimotor blockade.Materials and Methods:In a double-blind study design, 75 adult patients were randomly divided into three groups: Group B, 3 ml of 0.5% hyperbaric bupivacaine; Group BF, 3 ml of 0.5% hyperbaric bupivacaine + 25 mcg of fentanyl; and Group BFM, 3 ml of 0.5% hyperbaric bupivacaine + 25 mcg of fentanyl + 1 mg of midazolam. Postoperative analgesia was assessed using visual analog scale scores and onset and duration of sensory and the motor blockade was recorded.Results:Mean duration of analgesia in Group B was 211.60 ± 16.12 min, in Group BF 420.80 ± 32.39 min and in Group BFM, it was 470.68 ± 37.51 min. There was statistically significant difference in duration of analgesia between Group B and BF (P = 0.000), between Group B and BFM (P = 0.000), and between Group BF and BFM (P = 0.000). Both the onset and duration of sensory and motor blockade was significantly prolonged in BFM group.Conclusion:Intrathecal midazolam potentiates the effect of intrathecal fentanyl in terms of prolonged duration of analgesia and prolonged motor and sensory block without any significant hemodynamic compromise.

Comparison of Effect of Intrathecal Buprenorphine vs Clonidine as an Adjuvant to Hyperbaric Bupivacaine on Subarachnoid Block Characteristics

Comparison of Effect of Intrathecal Buprenorphine vs Clonidine as an Adjuvant to Hyperbaric Bupivacaine on Subarachnoid Block Characteristics

Preemptive analgesia of oral clonidine during subarachnoid block for laparoscopic gynecological procedures: A prospective study.

Background:Preemptive analgesia is known modality to control the peri-operative pain. The present study was aimed to evaluate the effects of oral clonidine on subarachnoid block characteristics, hemodynamic changes, sedation and respiratory efficiency in patients undergoing laparoscopic gynecological procedures.Patients and Methods:A total of 64 adult consenting females of American Society of Anesthesiologist physical status I and II were randomized double blindly into two groups of 32 patients each. Patients in the clonidine group received oral clonidine (100 μg) and patients of the control group received placebo capsule, 90 min before subarachnoid block with 0.5% hyperbaric bupivacaine (3.5 ml). The onset of sensory and motor block, maximum cephalic sensory level and regression times of sensory and motor blockade were assessed. Intra-operative hemodynamic changes, respiratory efficiency, shoulder pain and sedation score were recorded. The other side-effects, if any were noted and managed.Results:The onset of sensory blockade was earlier in patients of clonidine group with prolonged duration of analgesia (216.4 ± 23.3 min vs. 165.8 ± 37.2 min, P < 0.05), but no significant difference was observed on motor blockade between groups. The hemodynamic parameters and respiratory efficiency were maintained within physiological limits in patients of clonidine group and no patient experienced shoulder pain. The Ramsey sedation score was 2.96 ± 0.75. In the control group, 17 patients experienced shoulder pain, which was effectively managed with small doses of ketamine and 15 patients required midazolam for anxiety.Conclusion:Premedication with oral clonidine (100 μg) has enhanced the onset and prolonged the duration of spinal analgesia, provided sedation with no respiratory depression. The hemodynamic parameters remained stabilized during the pneumoperitoneum.

Neuraxial opioids in geriatrics: A dose reduction study of local anesthetic with addition of sufentanil in lower limb surgery for elderly patients

Background and Objectives:Neuraxial anesthesia in the elderly is associated with exaggerated responses to conventional doses of local anesthetics, thereby increasing the incidence of hemodynamic complications. A double-blind prospective study was carried out in our institute with an aim to compare the hemodynamic stability and quality of the conventional dose of hyperbaric bupivacaine (LA) with low dose of LA and sufentanil in elderly patients scheduled for lower limb surgery, randomized to receive combined spinal epidural anesthesia.Methods:A total of 50 elderly patients of ASA grade I and II, divided randomly into groups I and II, of either sex undergoing lower limb surgery under combined spinal epidural anesthesia at our institute attached to a Government Medical College were enrolled for study. Group I received 2.5 ml of intrathecal hyperbaric bupivacaine (LA), while group II received 1.5 ml of intrathecal LA+0.1 ml sufentanil (5 μg). Both initial and postoperative subarachnoid block characteristics, hemodynamic and respiratory parameters, duration of analgesia, and side effects were observed and recorded. Statistical analysis was carried out using Chi-square and paired t test.Results:Demographic profile was comparable in both groups. Group I had a greater incidence of hypotension and, consequently, higher use of vasopressors (P<0.05). Onset of sensory analgesia, time to achieve peak sensory level, and recovery from motor blockade were significantly earlier in group II (P<0.05). Postoperative consumption of LA through epidural route was significantly higher in group I (P<0.05). The side effect profile was similar, except for a significantly higher incidence of shivering in group I (P<0.05).Conclusions:The study established that the dose of a local anesthetic can be safely and significantly lowered by 40%, with addition of low-dose sufentanil, thereby avoiding the hemodynamic fluctuation and providing a stable perioperative and postoperative period in the geriatric population. In addition, duration of sensory analgesia is prolonged and postoperative requirement for the epidural top-up also decreases.

Preoperative Gabapentin: The Effect on Ropivacaine Subarachnoid Block and Hemodynamics

Gabapentin is an adjuvant analgesic and may enhance the spread of subarachnoid block. We investigated the effects of pretreatment with gabapentin on subarachnoid block characteristics and hemodynamics. Seventy patients undergoing transurethral procedures under subarachnoid anesthesia with 2.2 mL of 0.75% ropivacaine were randomly assigned to receive preoperatively 400 mg of gabapentin 6 hourly, up to a total dose of 1200 mg, or placebo. Sensory and motor blocks were assessed every 30 min until regression of sensory block to L4. At the same time intervals, systolic and diastolic arterial blood pressures and heart rate were recorded. There were no differences between groups in the sensory block levels or degree of motor block. Sensory block 150 min after the subarachnoid injection had regressed to L4 in 26 of 32 patients in the gabapentin group and in 25 of the 33 patients in the control group. Systolic arterial blood pressure was decreased in the gabapentin group (P = 0.002 for the main effect of group, and P = 0.03 at 60 min between the groups). The diastolic arterial blood pressure did not differ between the groups, but overall, the heart rate was more rapid in the gabapentin group (P = 0.002, but only for baseline values between the groups, P = 0.036). Pretreatment with gabapentin had no effect on the spread of sensory block or the regression of motor block but was associated with lower systolic arterial blood pressure values in patients undergoing subarachnoid anesthesia with ropivacaine.

Effect of Addition of Various Doses of Fentanyl Intrathecally to 0.5% Hyperbaric Bupivacaine on Perioperative Analgesia and Subarachnoid-Block Characteristics in Lower Abdominal Surgery

Effect of Addition of Various Doses of Fentanyl Intrathecally to 0.5% Hyperbaric Bupivacaine on Perioperative Analgesia and Subarachnoid-Block Characteristics in Lower Abdominal Surgery

Effect of Addition of Various Doses of Fentanyl Intrathecally to 0.5% Hyperbaric Bupivacaine on Perioperative Analgesia and Subarachnoid-Block Characteristics in Lower Abdominal Surgery: A Dose–Response Study

The purpose of this randomized, double-blind, placebo-controlled trial is to study the effect of adding various doses of fentanyl to 2.2 mL of bupivacaine (0.5% hyperbaric), for spinal anesthetic in non-obstetric population undergoing superficial lower abdominal surgery (hernia repair). A population of 60 patients belonging to ASA classes I and II, scheduled for elective inguinal hernia repair, were randomized to receive a spinal anesthetic with 2.2 mL of bupivacaine (0.5% hyperbaric) and saline (control group), or fentanyl 10, 20, 30, or 40 microg. The volume of injected drug was kept constant at 3 mL by adding preservative-free saline for blinding purposes. Subarachnoid block characteristics, drug-related side effects, and postoperative analgesia requirements were assessed and recorded. Significant improvement in quality and duration of analgesia occurred in treatment groups (receiving fentanyl and bupivacaine) compared with the control group (saline and bupivacaine) (P < .05). However, no improvement in analgesia occurred when the dose of fentanyl added was increased from 10 to 20, 30, or 40 microg. The data suggest that in a non-obstetric population receiving spinal anesthetic for superficial lower abdominal surgery (hernia repair), addition of 10 microg fentanyl to bupivacaine 0.5% (hyperbaric) significantly improves the quality and duration of analgesia. No further advantage occurs if the dose of fentanyl is increased up to 40 mug.

Effect of Addition of Fentanyl (10,20,30,or40 mcg), Intrathecally to 0.5% Hyperbaric Bupivacaine, on Perioperative Analgesia and Subarachnoid Block Characteristics, in Lower Abdominal Surgery.A Dose Response Study

Effect of Addition of Fentanyl (10,20,30,or40 mcg), Intrathecally to 0.5% Hyperbaric Bupivacaine, on Perioperative Analgesia and Subarachnoid Block Characteristics, in Lower Abdominal Surgery.A Dose Response Study