Different Doses Of Bupivacaine Research Articles

Intrathecal Co-administration of Morphine Facilitated the Anti-nociceptive of Bupivacaine in a Rat Model of Acute Postoperative Pain.

Introduction: Bupivacaine is one of the commonly used agents for spinal anaesthesia. Moreover, co-administration with morphine can likely increase its anti-nociceptive effect bringing about a reduction in the required dose of bupivacaine. Though this has been observed clinically, preclinical studies on the efficacy of this drug combination are lacking.Methods: Sprague Dawley rats, previously implanted with intrathecal catheters, were administered either bupivacaine (30 mcg) or morphine (30 mcg) or both bupivacaine and morphine (15 mcg each). These doses were determined following prior evaluation of different doses of bupivacaine (3, 10 and 30 mcg). Rats were subjected to hind paw incision under isoflurane anaesthesia, 15 min after drug administration. Anti-nociception was evaluated by estimating mechanical allodynia in a fixed peri-incisional area using von Frey filaments. This was done 4 h after the incision.Results: Both bupivacaine and morphine attenuated allodynia though morphine was more effective. Co-administration of both drugs at half the doses increased the antinociceptive effect of bupivacaine to the 30 mcg dose level.Conclusion: The underlying reason for this enhanced anti-nociception could be the different neural mechanisms responsible for anti-nociception. Local anaesthetics inhibit the generation of action potentials by blocking sodium channels whereas opioids like morphine act through G-protein coupled mu opioid receptor-linked closure of calcium channels in presynaptic terminals. In conclusion, the addition of morphine can facilitate bupivacaine’s anti-nociceptive effect following intrathecal administration. This information could have clinical relevance in the treatment of postoperative pain.

A Randomised Controlled Study of Two Different Doses of Bupivacaine in Ultrasound Guided Axillary Brachial Plexus Block

Introduction: The use of Ultrasound (USG) for needle precision aids in reduction of local anaesthetic volume needed for peripheral nerve blockade. Conventional dosages of 30 to 40 mL of local anaesthetic mixture have been used in peripheral nerve blockades but using a lesser volume will reduce the incidence of local anaesthesia associated systemic toxicity. Aim: To assess the efficacy of two different doses 20 mL and 25 mL of Bupivacaine in USG guided axillary plexus block. Materials and Methods: Sixty patients requiring forearm and hand surgeries were randomised into two groups. Group A received low volume (20 mL of 0.375% bupivacaine) and group B received intermediate volume (25 mL of 0.375% bupivacaine). The quality of anaesthesia in regards to sensory and motor blockade, duration of analgesia, haemodynamic variability and complications were evaluated. Successful block was defined by Vester Anderson’s criteria. Duration of analgesia was measured using Visual Analogue Scale (VAS). Statistical comparison of all continuous variables were assessed utilising Student’s t-test and Mann-Whitney U-test as applicable. Results: No significant difference in onset times were observed as far as sensory and motor blockade was concerned between the two groups A and B with p-values of 0.69 and 0.40, respectively. Group B had significantly longer duration of block in comparison with Group A (p<0.001). Two patients in group A and one patient in Group B required supplemental analgesia with fentanyl boluses. Haemodynamics were stable and no complications were seen in both the groups. Conclusion: Lower volume of Bupivacaine is convincingly prudent for regional blockade under USG guidance than suggested in literature.

Intraoperative and postoperative effects of different doses of bupivacaine: a comparative and prospective study for lower limbs surgeries

Background Central neuraxial block is the gold standard for surgeries below the level of the umbilicus, especially for lower limb operations. Bupivacaine of different concentrations are used for regional blocks and the side effects are attributed to the concentration of the local anaesthetics used. Objective The aim of this study was to prospectively investigate the intraoperative and postoperative effects of different doses of bupivacaine in lower limb surgeries. Methodology A double-blind randomized controlled study was conducted on 120 patients scheduled for emergency lower limb surgeries at Ahmadu Bello University Teaching Hospital from January to December 2017. The patients were randomly grouped into two groups: 1 and 2. The patients in group 1 received 10 mg of 0.5% bupivacaine and 10 μg of fentanyl, whereas those in group 2 received 7.5 mg of 0.5% bupivacaine and 10 μg of fentanyl. Parameters considered included the hemodynamic indices, quality of intraoperative analgesia, onset time of sensory and motor blockade, level of sensory and motor blockade, and duration of the sensory and motor blockade. A P value less than 0.05 was considered statistically significant. Results There was no statistically significant difference (P Conclusion This study has established that 7.5 mg of 0.5% bupivacaine with 10 μg fentanyl has operative analgesia of equal efficacy as 10 mg of 0.5% bupivacaine.

Comparative evaluation of Intrathecal Fentanyl with different doses of Bupivacaine on lower limb surgery

Introduction: Intrathecal administration of opioids and local anaesthetics provides good analgesia. Fentanyl potentiates the afferent surgical blockade and improves both intra and post operative analgesia. The synergism between intrathecal opioids and local anaestheticsachieves a reliable spinal anaesthesia with minimal hypotension. The optimal doses and dilutions of intrathecal combination of bupivacaine and fentanyl remain a subject of discussion. Therefore, we designed this study to compare the effects of different doses of hyperbaric bupivacaine 0.5% (10 mg, 12.5 mg, 15 mg) with fentanyl 25 microgram in subarachnoid block on quality of anaesthesia and recovery. Objectives: To observe sensory and motor blockcharacteristics and effects of different doses of bupivacaine on haemodynamic parameters. Method: A prospective randomized study was carried out on three groups of 20 each. Group A patients were given 0.5% hyperbaric bupivacaine 10 mg, fentanyl 25 µg and 0.9% normal saline 1.5 ml. Group B patients were given with 0.5% hyperbaric bupivacaine 12.5 mg, fentanyl 25 µg and 0.9% normal saline 1ml. Group C patients were given 0.5% hyperbaric bupivacaine 15 mg, fentanyl 25 µg and 0.9% normal saline 0.5 ml. Results: Duration of sensory block was prolonged in group C (139.50±16.05 minutes) than group A (129.00±18.32 minutes). On statistical comparison, group B and C (126.25±15.29 minutes and 132.75±10.70 minutes respectively) had significant prolonged duration of motor block than group A (114.00±18.11 minutes). Conclusion: Fentanyl 25µg with 0.5% hyperbaric bupivacaine 12.5 mg is superior in terms of characteristics of sensory and motor block and haemodynamic stability.

The Effect of Different Doses of Intrathecal Hyperbaric Bupivacaine Plus Sufentanil in Spinal Anesthesia for Cesarean Sections

BackgroundDecreasing side effects and improving the quality of block in caesarean sections by appropriate dosage of local anesthetics and adjuvants could play an important role in the safe management of cesarean section. The present study aimed at comparing the effects of 3 different doses of intrathecal hyperbaric bupivacaine injected with a fixed dose of sufentanil in cesarean sections.MethodsIn a double- blind randomized clinical trial, 105 candidates of elective cesarean section were randomly assigned into 3 groups of 8, 9, and 10 mg of intrathecal bupivacaine plus sufentanil 2.5 µg. The maximum level of sensory block, the intensity of motor block, and vital signs were measured at regular intervals. The incidence of hypotension and bradycardia were also recorded.ResultsNo significant difference was found between the maximum level of sensory block and the intensity of motor block in 3 groups. The incidences of hypotension and bradycardia as well as administration of atropine and ephedrine were comparable among the 3 groups (P > 0.05).ConclusionsAccording to similar effects of different doses of bupivacaine, administration of lower doses of bupivacaine (8mg) is more reasonable for spinal anesthesia for cesarean section.

Effects on QTc Interval of 2 Different Doses of Spinal Anesthesia in Inguinal Hernia Operations.

BackgroundCardiac arrhythmia is a significant cause of morbidity and mortality. In this study, through examination of the effects on the QTc interval of different doses of hyperbaric bupivacaine, we investigated the relationship with arrhythmia.Material/MethodsA total of 60 patients were separated into 2 groups: spinal block was applied with 10 mg bupivacaine to Group S1 and with 15 mg to Group S2. The mean arterial pressure (MAP) and heart rate (HR) values were recorded before the spinal block and at 5 and 30 min after the block and at 60 min postoperatively. By recording the time of the spinal sensory block to reach T10 dermatome (Anaesth T) and the duration of the surgical procedure (Surg T.), the QTc intervals were calculated.ResultsThe demographic data were similar in both groups. A statistically significant difference was determined between the S1 and S2 groups between the baseline and the 30 mins after spinal block QTc intervals (p=0.001). No statistically significant difference in HR values was determined between the groups at baseline, 5 min after spinal block, and 1 h after surgery (all p>0.05), but at 30 min after spinal block value there was a statistically significant difference (p=0.010). No statistically significant difference was determined in MAP values between the groups at baseline and 1 h after surgery (p>0.05).ConclusionsThe QTc interval lengthened in a dose-dependent manner after spinal anesthesia was applied with different doses of bupivacaine, but the doses used did not cause any severe arrhythmia.

Cardiovascular tolerance of intravenous bupivacaine in broiler chickens (Gallus gallus domesticus) anesthetized with isoflurane

ObjectiveTo determine the median effective dose (ED50) of intravenous (IV) bupivacaine associated with a 50% probability of causing clinically relevant cardiovascular effects [defined as 30% change in heart rate (HR) or mean arterial pressure (MAP)] in chickens anesthetized with isoflurane. Study designRandomized up-and-down study. AnimalsA total of 14 Ross-708 broiler chickens (Gallus gallus domesticus) weighing 1.70–2.75 kg. MethodsAnesthesia was induced and maintained with isoflurane. Monitoring included the electrocardiogram and invasive arterial pressures. Chickens were administered bupivacaine IV over 2 minutes using a dose based on the response of the previous animal. Dose was decreased when HR and/or MAP in the previous animal increased or decreased ≥30% after bupivacaine administration, or increased when HR or MAP changed <30%. The ED50 was defined as the dose resulting in ≥30% variation in HR or MAP in 50% of the population studied. ResultsThe IV ED50 of bupivacaine was 1.94 mg kg−1 using Dixon’s up-and-down method and 1.96 mg kg−1 by logistic regression. Conclusions and clinical relevanceThese results suggest that 1.33 and 1.96 mg kg−1 of IV bupivacaine are associated with a respective 1 or 50% probability of a clinically significant change in MAP in isoflurane-anesthetized chickens. Identification of the cardiovascular changes associated with different doses of bupivacaine can be used as the basis for studies of therapeutic applications in the domestic chicken. Further studies are required to determine interspecies variation.

Comparison of the safety of different doses of bupivacaine combined with epidural anesthesia for delivery women undergoing cesarean operation

Objective To explore the safety of different doses of bupivacaine combined with epidural anesthesia for delivery women undergoing cesarean operation. Methods A total of 120 cases of parturient women with cesarean section surgery were randomly divided into A, B, C three groups (40 cases in each group). A group was subarachnoidly given 0.5% levobupivacaine 1.5mL(7.5mg), B group was given 0.5% levobupivacaine 2.0mL(10.0mg), C group was given 0.5% levobupivacaine 2.5mL(12.5mg). The anesthesia effect in three groups was recorded. Results 5 min after anesthesia, the central venous pressure, heart rate, blood oxygen saturation in A group were (79.47±10.65)mmHg, (83.94±8.21)times/min, (98.16±1.17)%, which in B group were (76.38±10.15)mmHg, (84.03±8.19)times/min, (98.48±1.06)%, which in C group were (66.28±18.49)mmHg, (76.38±5.68)times/min, (95.03±0.45)%.10 min after anesthesia, the central venous pressure, heart rate, blood oxygen saturation in A group were (83.54±10.03)mmHg, (84.03±8.34)times/min, (98.25±1.19)%, which in B group were (82.46±10.11)mmHg, (83.95±8.24)times/min, (98.04±1.15)%, which in C group were (69.06±17.03)mmHg, (74.19±5.48)times/min, (94.85±0.41)%, the changes of heart function index in A group and B group had statistically significant differences compared with those in C group(F=5.165, 6.487, 7.125, 6.145, 5.378, 6.145, all P<0.05). In A group, excellent anesthesia in 9 cases, good in 17 cases, and poor in 14 cases; those in B group were 24 cases, 13 cases, 3 cases; those in C group were 28 cases, 11 cases and 1 case.The anesthesia effect of B group and C group was significantly higher than A group(χ2=4.887, P<0.05). In A group, hypotension occurred in 1 case, bradycardia in 2 cases, 2 cases had nausea and vomiting, shortness of breath 0 case.In B group, hypotension occurred in 2 cases, 2 cases of bradycardia, nausea and vomiting 3 cases, difficulty in breathing in 1 case.In C group, 15 cases of hypotension, bradycardia in 11 cases, 14 cases had nausea and vomiting, dyspnea in 7 cases.The incidence rate of adverse reactions of C group was higher than A group and B group(χ2=4.168, 5.122, 4.784, 5.122, all P<0.05). Conclusion The anesthesia effects of levobupivacaine combined spinal and epidural anesthesia in cesarean section surgery is related with dosage, the greater the dosage, the anesthesia effect is stronger, but the circulation disturbance, the greater the use the share such as 10mg dose of levobupivacaine is more suitable, worthy of popularization and application in clinic. Key words: Cesarean section; Anesthesia; Levobupivacaine

Randomized Clinical Comparison of Three Different Doses of Bupivacaine with Fentanyl for TURP-Search for Optimal Dose to Be Used in Day Care Urological Procedures

Background: Patients who are candidates for TURP are elderly with cardiovascular and respiratory diseases with anticipated problems during spinal anesthesia. Aim: To compare three different doses (5mg, 7.5mg and 10mg) of Bupivacaine after adding 25 mcg of fentanyl during spinal anesthesia in transurethral resection of prostate surgeries. Methods: Single blinded Randomized clinical study conducted in 75 patients. The subjects were allocated in to three groups. Group A - received Inj. 0.5% Bupivacaine 5 mg, Group B- received Inj. 0.5% Bupivacaine 7.5 mg, Group C received Inj.0.5% Bupivacaine 10 mg added with 25 mcg of Fentanyl. Baseline and intraoperative vital parameters, time to sensory block at t10, maximum sensory height, time to two segment sensory regression, total duration of sensory blockade, grading of motor blockade and total duration of motor blockade were recorded. Results: Maximum sensory level achieved in Group A was T9, Group B T7 and in Group C it was T5. Time to T10 level in Group A was 7.88 ±0.80 minutes, Group B 5.41 ±0.50 minutes and Group C 3.33 ±0.65 minutes. Two segment sensory regression times in Group A was 56.8±13.61 minutes, Group B 79.58 ±25.32 minutes, and Group C was 116.25 ±9.35 minutes. Total duration of pain free interval in Group A was 84.6 ±20.41 minutes, Group B 104.12 ±45.89 minutes. Group C was 194.20 ±41.53 minutes. Conclusion: Low dose of Bupivacaine (5mg) with addition of Fentanyl 25 μg can be used for painless TURP surgeries when compared to higher doses (7.5mg and 10 mg) without any major side effects and facilitates early discharge.

Effect of retigabine on median effective dose of bupivacaine and chloroprocaine for induction of convulsion in mice

Objective To investigate the effect of KCNQ2/3 channel opener retigabine on the median effective dose (ED50) of bupivacaine and chloroprocaine for induction of convulsion in mice and the relationship between KCNQ2/3 channels and the neurotoxicity of local anesthetics.Methods Pathogen-free female Kunming mice,weighing 20-30 g,were used in the study.The experiment was performed in two parts.Part Ⅰ Sixty mice were randomly divided into 2 groups (n =30 each):control group (group C) and retigabine group (group R).The C and R groups were further divided into 3 subgroups with different doses of chlorprocaine (C + L1,C + L2 and C+ L3 groups,and R+ L1,R+ L2 and R+ L3 groups,n =10 each).In groups C and R,0.9％ normal saline 0.005 ml/g and retigabine 20 mg/kg were injected intraperitoneally,respectively,and chlorprocaine was injected intraperitoneally 20 min later.The doses of chlorprocaine were 150.0,172.5 and 198.4 mg/kg in C + L1,C + L2 and C + L3 groups,respectively,and 198.4,228.2 and 262.4 mg/kg in R+ L1,R+ 12 and R+ L3 groups,respectively.Part Ⅱ Eighty mice were randomly divided into 2 groups (n =40 each):control group (group C) and retigabine group (group R).The C and R groups were further divided into 4 subgroups with different doses of bupivacaine (C + B1,C + B2,C + B3 and C + B4 groups,and R + B1,R + B2,R + B3 and R + B4 groups,n =10 each).In groups C and R,0.9％ normal saline 0.005 ml/g and retigabine 20 mg/kg were injected intraperitoneally,respectively,and bupivacaine was injected intraperitoneally 20 min later.The doses of bupivacaine were 37.8,43.5,50.0 and 57.5 mg/kg in C + B1,C + B2,C + B3 and C + B4 groups,respectively,and 50.0,57.5,66.1 and 76.0 mg/kg in R + B1,R + B2,R + B3 and R + B4 groups,respectively.The ED50 and 95％ confidence interval (CI) of bupivacaine and chloroprocaine for induction of convulsion were calculated by Probit analysis.Results The ED50(95％ CI) of chloroprocaine was 165.3 (155.8-175.0) mg/kg,and the ED50(95％CI) of bupivacaine was 41.1 (36.7-44.5) mg/kg in C group.The ED50 (95％ CI) of chloroprocaine was 212.4 (200.2-224.3) mg/kg,and the ED5o (95％ CI)of bupivacaine was 51.5 (945.1-56.0)mg/kg in R group.Compared with group C,the ED50 of bupivacaine and chloroprocaine for induction of convulsion was significantly increased in group R (P ＜ 0.01).Conclusion KCNQ2/3 channel opener retigabine can significantly increase the ED50 of bupivacaine and chloroprocaine for induction of convulsion and reduce convulsion induced by bupivacaine and chloroprocaine in mice,indicating that the neurotoxicity of local anesthetics is related to inhibition of KCNQ2/3 channels. Key words: KCNQ2 potassium channel; KCNQ3 potassium channel; Anesthetics, local; Drug toxicity ; Dose-response relationship, drug

A comparison of two different doses of bupivacaine in caudal anesthesia for neonatal circumcision

A comparison of two different doses of bupivacaine in caudal anesthesia for neonatal circumcision

Prolongation of epidural bupivacaine effects with hyaluronic acid in rabbits

To assess the prolongation of epidural bupivacaine by hyaluronic acid viscous formulations we designed a cross-over study in rabbits. Different doses of bupivacaine (3 or 6 mg) either as a solution (bupivacaine hydrochloride), or as viscous formulations with hyaluronic acid (bupivacaine base and bupivacaine hydrochloride) were administered in a rabbit model of epidural anesthesia. In the first part of the study, in vitro release characteristics were determined. Then pharmacodynamic effects and pharmacokinetic profiles of each bupivacaine formulation were studied. The rank order release rate of bupivacaine in vitro was always hydrochloride solution⪢viscous physical mixture of bupivacaine with hyaluronic acid>viscous ionic complex of bupivacaine base with hyaluronic acid. Onset time of epidural anesthesia was similar whatever the formulation of bupivacaine used. We did not find any blockade prolongation when 3 mg bupivacaine was administered, but significant blockade prolongations were observed with viscous formulations incorporating 6 mg bupivacaine. The observed reduction in the absorption rate of bupivacaine into the systemic circulation for both viscous hyaluronic formulations after 6 mg of bupivacaine may explain the prolongation of spinal effects. Drug release and duration of action were found to be viscosity controlled as linear relationships were found between pharmacodynamic effects and viscosity. Our results were in accordance with those reported with bupivacaine–cyclodextrin complex, another formulation with a molecular dispersion of the drug, resulting in a moderate prolongation of action.

Effects of adding midazolam on the postoperative epidural analgesia with two different doses of bupivacaine

Study Objective: To investigate the interaction of midazolam with different doses of bupivacaine, by comparing the analgesic, sedative, and amnesic effects of continuous epidural midazolam with two different doses of bupivacaine. Design: Prospective, randomized study. Setting: Operating room and intensive care units of a university hospital. Patients: 100 ASA physical status I and II postgastrectomy patients (40–70 yrs) without any complications. Interventions: Patients were divided into four groups (n = 25) and administered continuous thoracic epidural infusion (40 mL/12 hr) of the drugs via a balloon infuser. The contents of the infuser (40 mL) were bupivacaine 180 mg with midazolam 20 mg (HM group), 90 mg with midazolam 20 mg (LM group), 180 mg without midazolam (HC group), or 90 mg without midazolam (LC group). As a rescue medication, 50 mg indomethacin suppository was the first choice, then IM pentazocine 15 mg. Measurements: Analgesia and sedation scores, blood pressure (BP), heart rate, respiratory rate, oxygen saturation, amnesia, the number of rescue medications, and time to the first rescue medication were monitored. The area under the curves (AUCs) of analgesia and sedation scores, and BP were calculated. Main Results: In the HM group, significantly better analgesia and sedation were obtained and the number of rescue medications given was the lowest of the four groups. The time to the first rescue medication was longest in the HM group, followed by the LM group, then the HC, and, finally, LC groups. The numbers of the patients with amnesia were greater in the HM and LM groups than the HC and LC groups. Blood pressure decreased significantly in the HM group but no treatment was necessary. The AUCs of analgesia and sedation scores, and BP were lowest in the HM group. Conclusions: Adding midazolam increased not only analgesic but also sedative effect with increasing dose of bupivacaine in a postoperative continuous epidural administration.

Motor blockade by brachial plexus block in the sheep.

Motor blockade by brachial plexus block in the sheep.

A dose–response study of epidural liposomal bupivacaine in rabbits

Liposomes are drug delivery systems used to prolong local effects of bupivacaine. We studied the relationships between motor and hemodynamic changes and epidural doses of plain bupivacaine (P) and liposomal bupivacaine (L) in rabbits equipped with chronical lumbar epidural and femoral arterial catheters. Liposomal (phosphatidylcholine–cholesterol) suspensions contained 20 mg ml −1 of lipid, and different doses of bupivacaine (Lipo 7.5=7.5-; Lipo 3.7=3.75-; Lipo 2.5=2.5-; Lipo 1.2=1.25-; and Lipo 0.7=0.65-mg of bupivacaine per ml). Forty rabbits were randomly assigned to five groups to receive epidural anesthesia (1 ml) as follows: Groups I to V received 0.65 to 7.5 mg of bupivacaine as P then as L. Release rate of bupivacaine from liposome was significantly slower using Lipo 3.7 than after Lipo 2.5 ( T d was 3.9 h and 1.7 h respectively). Increasing the doses of L and P resulted in faster onset time for complete motor blockade and in a prolonged duration of motor effects. Liposomal formulation appears to be a powerful delivery system to prolong the motor effects of bupivacaine since E 50 was lower and E max higher than after the use of plain solution ( E 50 4.49±1.81 mg and E max 152±40 min for P; and E 50 2.61±0.23 mg and E max 202±9 min for L). Hemodynamic changes were linearly related to doses of bupivacaine injected. The best bupivacaine-to-lipid ratio to prolong motor effects using our model was 3.75 mg and 20.0 mg respectively (Lipo 3.7).