Maximum Block Research Articles

Intrathecal ropivacaine with or without tramadol for lower limb orthopedic surgeries.

Background and Aim: Preservative free tramadol has been used as an adjuvant to intrathecal bupivacaine. However, the effect of the addition of tramadol on intrathecal isobaric ropivacaine has never been studied.Material and Methods: This prospective, randomized, double-blind study was conducted in 50 adult male American Society of Anesthesiologists grade I or II patients, aged 18–60 years, being operated for unilateral femur fractures. An epidural catheter was inserted in L2-L3 interspace and subarachnoid block was given in L3-L4 space. The patients were randomized to receive 0.5 mL normal saline (group R) or 0.5 mL (25 mg) preservative free tramadol (group RT) with 2.5 mL of 0.75% intrathecal ropivacaine. Hemodynamic parameters, sensory level, motor block, sedation and side-effects were recorded. Statistical analysis was done using Student's t-test, Chi-square test, Fischer's exact test and repeated measures ANOVA.Results:The time of sensory block onset was 9.2 ± 4.9 min and 8.6 ± 5.3 min (P = 0.714) in group R and group RT, respectively. The motor block onset was also comparable in both the groups (P = 0.112). The duration of sensory block was 147.2 ± 37.4 min in group R and 160.4 ± 40.9 min in group RT (P = 0.252). The median maximum block height achieved in both the groups was T6 and the time to achieve the maximum block was also comparable statistically (P = 0.301).Conclusion: The addition of intrathecal tramadol 25 mg to the isobaric ropivacaine does not alter the block characteristics produced by intrathecal ropivacaine alone.

A randomized controlled study comparing intrathecal hyperbaric bupivacaine-fentanyl mixture and isobaric bupivacaine-fentanyl mixture in common urological procedures.

Background and Aims:Bupivacaine is available in isobaric and hyperbaric forms for intrathecal use and opioids are used as additives to modify their effects. The aim of this study was to compare the efficacy and haemodynamic effect of intrathecal isobaric bupivacaine-fentanyl mixture and hyperbaric bupivacaine-fentanyl mixture in common urological procedures.Methods:One hundred American Society of Anesthesiologists physical status 1 and 2 patients undergoing urological procedures were randomized into two groups. Group 1 received 3 ml of 0.5% isobaric bupivacaine with 25 μg fentanyl while Group 2 received 3 ml of 0.5% hyperbaric bupivacaine with 25 μg fentanyl. The parameters measured include heart rate, blood pressure, respiratory rate, onset and duration of motor and sensory blockade. Student's unpaired t-test and the χ2 test were used to analyse the results, using the SPSS version 11.5 software.Results:The haemodynamic stability was better with isobaric bupivacaine fentanyl mixture (Group 1) than with hyperbaric bupivacaine fentanyl mixture (Group 2). The mean onset time in Group 1 for both sensory block (4 min) and motor block (5 min) was longer compared with Group 2. The duration of sensory block (127.8 ± 38.64 min) and motor block (170.4 ± 27.8 min) was less with isobaric bupivacaine group compared with hyperbaric bupivacaine group (sensory blockade 185.4 ± 16.08 min and motor blockade 201.6 ± 14.28 min). Seventy percent of patients in Group 2 had maximum sensory block level of T6 whereas it was 53% in Group 1. More patients in Group 1 required sedation compared to Group 2.Conclusion:Isobaric bupivacaine fentanyl mixture was found to provide adequate anaesthesia with minimal incidence of haemodynamic instability.

Assessment of Gura Raului Dam Safety Using Measurements of Structural Response to Ambient Vibrations

A very important research direction in today's dam engineering is related to structural ageing of concrete dams and ways to monitor structural and material characteristics changes to reduce and manage the associated risks.In situ ambient vibration measurements used to identify the dynamic characteristics of the structure and the development of hybrid models (the mathematical model bounded to a certain in situ measurement program and calibrated using the recorded data) represent an appealing method for the evaluation of the safety reserves of concrete water retention structures. However, mathematical modelling can be done with varying degrees of complexity and the results obtained for the couple dam model - recorded data can significantly vary depending on the size and complexity of the analyzed model.The presented study, developed for Gura Raului buttress dam in Romania, consisted in 2 measurements campaigns and the development of 4 mathematical models, via the finite element method, with different degrees of complexity - a representative maximum height block, a spillway block, the whole spillway made of 3 identical blocks and the complete dam made of 22 blocks. The paper presents the in situ measurement results, the calibration of the maximum height block based on the first measurement data set and the analysis of the results obtained for the other 3 models compared with the recorded data.

Two syringe spinal anesthesia technique for cesarean section: A controlled randomized study of a simple way to achieve more satisfactory block and less hypotension.

Background:Multiple trials have been tried to prevent hypotension during spinal anesthesia. However, the drug choice and mode of administration is still a matter of debate.Objectives:To compare the outcome of spinal injection of hyperbaric bupivacaine and fentanyl separately to standard injection of mixed fentanyl with hyperbaric bupivacaine.Settings and Design:A randomized, controlled clinical trial.Patients and Methods:One hundred twenty-four parturient scheduled for elective cesarean section were randomly allocated into two groups, each 62 parturient: Group M received spinal anesthesia using 10 mg bupivacaine 0.5% premixed with 25 μg fentanyl in the same syringe and Group S received 25 μg fentanyl in one syringe and 10 mg bupivacaine 0.5% without barbotage in a second syringe.Results:Patients with intraoperative pain that was controllable without the need for a shift to general anesthesia was significantly lower in Group S (3.2%) than in Group M (16.1%). The frequency of hypotension was significantly lower in Group S compared to Group M (P < 0.05). Time till the onset of sensory block was nonsignificantly shorter with nonsignificantly higher mean level of maximal sensory block in Group S compared to Group M (P > 0.05). There was no significant difference in the time till occurrence of hypotension, duration of hypotension, mean dose of ephedrine used for the treatment of hypotension and frequency of patients developed itching between the groups (P > 0.05).Conclusion:Separate intrathecal injection of fentanyl and hyperbaric bupivacaine provided a significant improvement in the quality of sensory block and significant reduction of the frequency of hypotension compared to injection of mixed medications.

Comparison of Neuromuscular Blockade with Rocuronium in Young and Elderly Patients with or without Renal Failure

ABSTRACT Context The duration of neuromuscular block with rocuronium is affected by old age as well as renal impairment. It would be helpful for anesthetists to know the variation in the block in elderly patients with renal failure and the significance of neuromuscular monitoring in this group. Aim The aim of our study is to investigate the neuromuscular effects of 0.6 mg/kg rocuronium under general anesthesia in young adults and elderly patients with or without renal failure. Study design Prospective randomized controlled study. Materials and methods Young and elderly 100 patients were divided into 4 groups of 25 each, with or without renal failure. General anesthesia with propofol 2 mg kg intravenous (iv), fentanyl 2 μg kg iv, and 60% N2O in O2 were given. Neuromuscular monitoring was started immediately after the induction of anesthesia and before the administration of muscle relaxant. After the stabilization of control responses, 0.6 mg kg rocuronium was injected intravenously. The onset time, time to achieve maximum block, and the recovery times were noted. Statistical analysis used The statistical analysis of the data from the study was performed with the Statistical Package for the Social Sciences (SPSS) software for Window Release 14.0. One-way analysis of variance, Bonferroni's, and chi-square test were used to compare patients’ characteristics. Results The duration of block as well as the recovery indices were significantly prolonged in the elderly compared to the young patients. Maximum prolongation was observed in the elderly group with renal failure. This underlines the importance of neuromuscular monitoring in these patients. How to cite this article Gvalani SK, Pradeep L. Comparison of Neuromuscular Blockade with Rocuronium in Young and Elderly Patients with or without Renal Failure. Res Inno in Anesth 2016;1(2):45-51.

Efficacy and potency of intrathecally administered bupivacaine and bupivacaine with midazolam in lower limb surgery at Ahmadabad, India

Background and Aim: Many drugs have been used for spinal anaesthesia in lower limb surgery e.g. Lignocaine, bupivacaine, ropivacaine etc. Bupivacaine is still considered as a standard drug as far as therapeutic and side effect profile is concerned. The aim of present study to evaluate efficacy and potency of intrathecally administered bupivacaine and bupivacaine with midazolam on sensory and motor blockade, hemodynamic stability, side effects and post operative pain relief in lower limb surgery. Methods: A randomized controlled study was conducted on 50 patients aged 20-70 years at AMC MET Medical College, Ahmadabad, Gujarat, India. Patients were scheduled for lower limb surgeries after taking informed consent. Patients who were selected and posted for surgeries were randomly allocated in two groups. Group A received 3 ml (15 mg) hyperbaric bupivacaine 0.5% plus 0.2 ml 0.9% saline and Group B received 3 ml (15 mg) hyperbaric bupivacaine 0.5% plus 0.2 ml (1 mg) preservative free midazolam. Duration of surgery for each case was noted. Pain measurement was done using VAS scale. Results: No statistically significant difference in duration of surgery was observed between the two groups. Difference between time to onset of sensory block and time to achieve maximum block height was not statistically significant between two groups (P > 0.05) maximum level of sensory block in both groups was between T6 – T10­. Conclusion: Addition of preservative free midazolam to intrathecal bupivacaine prolongs sensory blockade and postoperative analgesia without increasing motor blockade and any adverse effects. Keywords: Ahmadabad, Anaesthesia, Bupivacaine, Midazolam, Surgery

Comparison of different regimens of intravenous dexmedetomidine on duration of subarachnoid block.

Background and Aims:Many studies have studied the effect of intravenous dexmedetomidine on the prolongation of the duration of the subarachnoid block (SAB). These studies had administered dexmedetomidine using different regimens. This study was designed to find out the suitable regimen with maximum advantages and minimum disadvantages.Material and Methods:Ninety-three ASA 1 and 2 patients scheduled to undergo surgeries under SAB were randomly allocated into three groups namely B, M, and BM. After SAB, Group B received 0.5 μg/kg of dexmedetomidine bolus over 15 min, Group M received 0.5 μg/kg/h of dexmedetomidine infusion until the end of surgery, Group BM received both bolus and infusion.Results:The time to achieve T10 sensory level (SL) was significantly faster in the Groups B and BM than in the Group M. Maximum block height achieved was T4 and was same in all the groups. The Time to achieve maximum SL and Bromage 3 was comparable in all groups. The two-segment regression time and time to reach Bromage 0 was significantly higher in Groups M and BM than Group B. The time for a first request of analgesia was similar in Groups M and BM. The maximum sedation attained in all groups was Ramsay Sedation Score of 3. Side effects such as bradycardia, hypotension, and desaturation were comparable between the groups.Conclusion:We conclude that the continuous infusion of dexmedetomidine results in more advantages than just a bolus dose. Therefore, we suggest using only the maintenance dose of intravenous dexmedetomidine after subarachnoid blockade for prolonging the duration and achieving sedation.

Main degradation mechanism in AsTeGeSiN threshold switching devices

AsTeGeSiN threshold switching devices which have recently been reported as reliable selectors in 3D memories are investigated in terms of the main degradation mechanism. The trap-limited conduction mechanism is also applicable to AsTeGeSiN threshold switching devices. This is verified by the conduction currents at various temperatures. Using the trap-limited conduction mechanism, it is revealed that the trap generations primarily occur during pulse cycling measurements. This is also verified using low-frequency noise measurements. The increased trap densities are directly related to low-frequency noise densities. Also, the speed of the current degradation is estimated using the number of pulse cycles. An increase in the current level by pulse cycles is harmful to the read margin of a selector in 3D memories. Because of this effect, the block size of the 3D memory architecture is limited by suitable reading operation. For example, the maximum block size after 104 pulse cycles is reduced by almost 1/4 times than that before giving the pulse cycles for reliable operation. This degradation is a limiting factor for high-density 3D memories with AsTeGeSiN threshold switching devices as a selector. ©2015 Elsevier Science Ltd. All rights reserved.

Altered Cisatracurium Pharmacokinetics and Pharmacodynamics in Patients with Congenital Heart Defects.

The neuromuscular blocking agent cisatracurium is frequently used adjunctively in anesthesia to facilitate endotracheal intubation and to provide muscle relaxation during surgery. We aimed to determine the pharmacokinetics (PK)/pharmacodynamics (PD) of cisatracurium in patients with congenital heart defects (CHDs), such as ventricular septal defects and atrial septal defects, and to assess the effects of CHDs on the PK/PD profiles of cisatracurium. A modified two-compartment model with drug clearance from both compartments was best fitted to the PK data to determine the PK parameters. The model suggested that septal defects significantly lowered the rate of cisatracurium distribution from the central to peripheral compartment. The intercompartment rate constants k12 and k21 were significantly reduced (35%-60%, P < 0.05) in patients with ventricular septal defects and in patients with atrial septal defects compared with control patients. Consistently, septal defects caused a marked increase (160%-175%, P < 0.001) in the distribution half-life. Furthermore, significantly delayed pharmacodynamic responses to cisatracurium were observed in patients with septal defects. The onset time (i.e., the time to maximal neuromuscular block) was prolonged from 2.2 minutes to 5.0 minutes. PK/PD modeling suggested that reduced concentrations of cisatracurium in the effect compartment due to poorer distribution were the main cause of lagged pharmacodynamic responses. In conclusion, cisatracurium PK/PD were significantly altered in patients with septal defects. Our study should be of use in clinical practice for the administration of cisatracurium to patients with CHDs.

A randomised trial to compare the effect of addition of clonidine or fentanyl to hyperbaric ropivacaine for spinal anaesthesia for knee arthroscopy

Objectives: To evaluate the clinical effects of hyperbaric ropivacaine alone and with clonidine or fentanyl for spinal anaesthesia for knee arthroscopy.Methods: Sixty ASA I/II patients were randomised to receive spinal anaesthesia with hyperbaric ropivacaine alone (Group R), or with clonidine 15 μg (Group RC) or fentanyl 30 μg (Group RF). The sensory and motor block, time to micturition and side effects were assessed.Results: The three groups were similar in mean time to onset of sensory block at T10, height of block and time to maximum block. Sensory regression to S2 took longer in Groups RF and RC compared with Group R (p = 0.001 and p < 0.01, respectively). Time to requirement of rescue analgesia was longer in Groups RF and RC compared with Group R (p = 0.023 and 0.002, respectively). Time for complete regression of motor block and time to voiding were longer in group RC compared with group R (p = 0.022 and p = 0.013, respectively).Conclusion: The addition of fentanyl 30 μg to hyperbaric ropivacaine ma...

Anatomical study of the articular branch of the lateral pectoral nerve to the shoulder joint.

The purpose of this study was to document the distribution of the articular branch of the lateral pectoral nerve (LPN) to the shoulder and to identify a suitable point for its blockade. This study involved the dissection of 43 shoulders of 22 unembalmed cadavers (6 male and 16 female) to identify the LPN and its articular branch to the shoulder. To identify the suitable anatomical point for blocking the articular branch of the LPN, several anatomical landmarks around the shoulder were measured. The articular branch of the LPN to the shoulder was present in 29 of 43 cases (67.4%). The appropriate point to block the articular branch of the LPN was identified at a mean distance of 1.5cm below the clavicle, on the line connecting the closest points between the clavicle and the coracoid process, and at a mean depth of 1.0cm from the skin. The articular branch of the LPN to the shoulder, as well as the muscular and cutaneous branches of the LPN, covers a portion of the shoulder joint with suprascapular and axillary nerves. Surgeons might consider a peripheral block of the suprascapular, axillary, and LPNs to provide maximum block coverage after shoulder joint surgery.

A randomized controlled trial comparing haemodynamic stability in elderly patients undergoing spinal anaesthesia at L5, S1 versus spinal anaesthesia at L3, 4 at a tertiary African hospital.

Spinal anaesthesia is a routinely used anaesthetic technique in elderly patients (> 60 years) undergoing operations involving the lower limbs, lower abdomen, pelvis and the perineum. Spinal anaesthesia has several advantages over general anaesthesia including stable haemodynamic variables, less blood loss, less post-operative pain, faster recovery time and less post-operative confusion. Despite these advantages, the sympathetic blockade induced by spinal anaesthesia can result in hypotension, bradycardia, dysrhythmias and cardiac arrests. Conventionally, spinal anaesthesia is performed at the level of L3,4 interspace; with a reported incidence of hypotension in the elderly ranging between 65% and 69%. A possible strategy for reducing spinal induced hypotension would be to minimize the peak block height to as low as possible for the planned procedure. To determine the difference in haemodynamic stability between elderly patients undergoing spinal anaesthesia at L5, S1 interspace compared to those at L3, 4. Thirty two elderly patients scheduled for lower limb or pelvic surgery under spinal anaesthesia were randomized into 2 groups (control group and intervention group) using a computer generated table of numbers. Control group; received 2.5 mls 0.5% hyperbaric bupivacaine injected intrathecally at the L3, 4 interspace and Intervention group; 2.5mls 0.5% hyperbaric bupivacaine injected intrathecally at the L5, S1 interspace. The two groups had similar baseline characteristics in age, sex, body mass index and use of anti-hypertensive medications. There was 68.8% proportion of hypotension in the control group and 75% in the intervention group. The difference was not found to be statistically significant (p= 0.694). During the study period, there were 106 episodes of hypotension, out of which, 65 were in the control group and 41 in the intervention group (p=0.004).. Linear regression analysis of the decrease in mean arterial pressures (MAP) showed a higher decrease in MAP in the control group (p 0.018). There were more crystalloids used in the control group (1006mls ± 374) than in the intervention group (606mls ±211) with a p< 0.0001. There was no difference in the amounts of vasopressors used between the two groups (p=0.288). There was no difference in the change in heart rates, conversion to general anaesthesia, use of supplementary intravenous fentanyl and the peak maximum block level achieved. The time to peak maximum sensory block level was 9.06min and 13.07min in the control group and intervention groups, respectively (p<0.0001). Among this population, there was no difference in the proportion of those with hypotension between the elderly patients who received their spinal anaesthesia at L3,4 and those who received spinal anaesthesia at L5,S1. The intervention group had better outcomes with significantly less episodes of hypotension. It took a longer time to achieve a maximum peak sensory block in the intervention group. Performing spinal anaesthesia at the level of L5,S1 was found to provide an adequate sensory block for a wide range of pelvic, perineal and lower limb surgeries.

Interference effects on wind pressure distribution between two high-rise buildings

Interference effects on wind pressure distributions between two buildings with various configurations in tandem, oblique, and parallel arrangements were studied in detail by applying the synchronous pressure measurement technique. Configurations included six kinds of breadth ratios (Br=Binterfering/Bprincipal) and four kinds of height ratios (Hr=Hinterfering/Hprincipal). The characteristics of wind pressure distribution were further investigated in the most unfavorable parallel arrangements. Results showed that the mean pressure was often beneficial because of shielding, whereas the peak pressure of the lateral facade adjacent to the interfering building was mainly amplified. With increased Br and Hr, the corresponding shielding and amplification effects became more remarkable. When Hr<1 in tandem arrangement, the local mean and peak pressures on the lateral facade increased by 56% and 53%, respectively, because of the three-dimensional flow effects. The channeling effect in parallel arrangement should be given sufficient attention for the observed maximum interference factors (IFmax) of the mean and peak pressures reach up to 2.6 and 1.91, respectively. Finally, high precision regression equations were proposed to present the relationship between the maximum block interference factor (BIFmax) and building spacing in parallel arrangement.

Differences between acceleromyography and electromyography during neuromuscular function monitoring in anesthetized Beagle dogs

ObjectiveQuantitative neuromuscular monitoring is essential for studies of potency and duration of neuromuscular blocking agents, and for detecting residual paralysis in anesthetized patients. This investigation evaluates whether there are systematic differences between acceleromyography (AMG) and electromyography (EMG); two quantitative methods for monitoring neuromuscular block. Study designProspective. AnimalsTen healthy Beagle dogs. MethodsDogs were anesthetized with isoflurane and dexmedetomidine. Both ulnar nerves were stimulated with a train-of-four (TOF) pattern every 15 seconds. The magnitude of the first twitch (T1) and the TOF ratio (magnitude of T4/T1; TOFR) were quantified simultaneously with AMG and EMG, applied randomly to each extremity. The extent of maximal block (T1 depression) and onset time were measured by AMG and EMG during TOF monitoring after the administration of cisatracurium (0.05 mg kg−1). In addition, recovery of T1 to 25% and 75%, the recovery index (time between T1 of 25% and 75%), and recovery of the TOFR to 0.9 were used to characterize recovery from cisatracurium and were compared between monitors. Regression and Bland-Altman plots for T1 and TOFR were also created. ResultsMaximal block and onset time were not different between monitors. Time to recovery of T1 to 25% and 75%, and time to TOF ratio 0.9 was significantly shorter with AMG. The recovery index was not different between monitors. When the TOFR returned to 0.9 with AMG, EMG still measured considerable residual block (TOFR 0.47). Conclusions and clinical relevanceElectromyography consistently detected residual NMB when recovery from NMB was complete as assessed by AMG.

SPARCoC: a new framework for molecular pattern discovery and cancer gene identification.

It is challenging to cluster cancer patients of a certain histopathological type into molecular subtypes of clinical importance and identify gene signatures directly relevant to the subtypes. Current clustering approaches have inherent limitations, which prevent them from gauging the subtle heterogeneity of the molecular subtypes. In this paper we present a new framework: SPARCoC (Sparse-CoClust), which is based on a novel Common-background and Sparse-foreground Decomposition (CSD) model and the Maximum Block Improvement (MBI) co-clustering technique. SPARCoC has clear advantages compared with widely-used alternative approaches: hierarchical clustering (Hclust) and nonnegative matrix factorization (NMF). We apply SPARCoC to the study of lung adenocarcinoma (ADCA), an extremely heterogeneous histological type, and a significant challenge for molecular subtyping. For testing and verification, we use high quality gene expression profiling data of lung ADCA patients, and identify prognostic gene signatures which could cluster patients into subgroups that are significantly different in their overall survival (with p-values < 0.05). Our results are only based on gene expression profiling data analysis, without incorporating any other feature selection or clinical information; we are able to replicate our findings with completely independent datasets. SPARCoC is broadly applicable to large-scale genomic data to empower pattern discovery and cancer gene identification.

Comparison of intrathecal magnesium and fentanyl as adjuvants to hyperbaric bupivacaine in preeclamptic parturients undergoing elective cesarean sections

<b>Aims:</b> The aim of this study was to evaluate the onset, duration of sensory and motor block, hemodynamic effects (if any), duration and quality of postoperative analgesia, and adverse effects of magnesium or fentanyl given intrathecally with hyperbaric 0.5% bupivacaine in patients with mild preeclampsia undergoing elective caesarean sections.<br><b>Materials and Methods:</b> A total of 60 women with mild preeclampsia undergoing elective cesarean section were included in a prospective, double-blind, controlled trial. Patients were randomly assigned to receive spinal anesthesia with 2 mL 0.5% hyperbaric bupivacaine with 12.5 μg fentanyl (Group F) or 0.1 mL of 50% magnesium sulfate (50 mg) (Group M) with 0.15 ml preservative free distilled water. Onset, duration and recovery of sensory and motor block, time to maximum sensory block, duration of spinal anesthesia and postoperative analgesia requirements were studied. Statistical comparison was carried out using the Chi-square or Fisher's exact tests and independent Student's <i>t</i>-test where appropriate.<br><b>Results:</b> The onset of both sensory and motor block was slower in the magnesium group. The duration of spinal anesthesia (246 min ± 11 min vs. 284 min ± 15 min; <i>P</i> < 0.001) and motor block (186.3 ± 12 min vs. 210 ± 10 min; <i>P</i> < 0.001) were significantly longer in the magnesium group. Total analgesic dose requirement was less in Group M. Hemodynamic parameters were comparable in the two groups. Intrathecal magnesium caused minimal side effects.<br><b>Conclusions:</b> The addition of magnesium sulfate 50 mg to bupivacaine for sub-arachnoid block in patients with mild preeclampsia undergoing elective cesarean section prolongs the duration of analgesia and reduces postoperative analgesic requirements without additional side effects and adverse neonatal outcomes

A randomized clinical study comparing spinal anesthesia with isobaric levobupivacaine with fentanyl and hyperbaric bupivacaine with fentanyl in elective cesarean sections.

Background:To date, racemic bupivacaine is the most popular local anesthetic for spinal anesthesia in parturients undergoing elective cesarean delivery. With the introduction of levobupivacaine as pure S (–) enantiomer of bupivacaine which offers advantages of lower cardiotoxicity and neurotoxicity and shorter motor block duration, its use has widely increased in India. However, very few studies have been conducted about its efficacy in obstetric anesthesia. Thus, this study was undertaken to compare the sensorial, motor block levels, and side-effects of equal doses of hyperbaric bupivacaine and levobupivacaine with intrathecal fentanyl addition in elective cesarean cases.Materials and Methods:After approval of College Ethical Committee, 30 parturient with American Society of Anesthesiologists I-II undergoing elective cesarean section were enrolled for study with their informed consent. They were randomly divided equally to either Group BF receiving 10 mg (2 ml) hyperbaric bupivacaine and 25 mcg (0.5 ml) fentanyl, or Group LF receiving 10 mg (2 ml) isobaric levobupivacaine and 25 mcg (0.5 ml) fentanyl. Sensory and motor block characteristics of the groups were assessed with pinprick, cold swab, and Bromage scale; observed hemodynamic changes and side-effects were recorded. Effects on the neonate were observed by APGAR score at 1 and 5 min and umbilical cord blood gas analysis.Results:Hemodynamic parameters like mean arterial pressure of Group BF were found to be lower. Group BF exhibited maximum motor block level whereas in Group LF, max sensorial block level and postoperative visual analog scale scores were higher. Umbilical blood gas pCO2 was slightly higher, and pO2 was marginally lower in Group BF. Onset of motor block time, time to max motor block, time to T10 sensorial block, reversal of two dermatome, the first analgesic need were similar in both groups.Conclusion:Intrathecal isobaric levobupivacaine-fentanyl combination is a good alternative to hyperbaric bupivacaine-fentanyl combination in cesarean surgery as it is less effective in motor block, it maintains hemodynamic stability at higher sensorial block levels.

Effect of intravenous dexmedetomidine on bupivacaine spinal analgesia

Background: Dexmedetomidine, a new α2 agonist, has been proven to prolong spinal anesthesia when administered through intrathecal route. This study was conducted to evaluate the effects of intravenous (IV) dexmedetomidine on spinal bupivacaine anesthesia. Materials and Methods: A prospective, randomized, double-blind, and placebo-controlled study was conducted on 80 female patients with the American Society of Anesthesiologists (ASA) grades I and II, aged 18-65 years undergoing abdominal hysterectomy under spinal anesthesia. After spinal anesthesia, patients in group D received a loading dose of 1 μg/kg IV dexmedetomidine over 10 min and followed by a dose of 0.2 μg/kg/h till the end of operative procedure, while patients in group C received the same calculated volume of normal saline. The time to reach peak sensory block level, time taken for two segment regression and maximum motor block, Ramsay sedation score, modified Bromage score, and visual analogue scale were recorded and were statistically analyzed using Statistical Package for Social Sciences (SPSS Inc. Chicago, IL, USA) Windows-based version 16.0. Results: Sensory regression to S1 was prolonged in the dexmedetomidine group compared to the control group (294 ± 18.2 min vs. 288 ± 24.3 min, P < 0.05). The time taken for motor block regression to modified Bromage score 6 in groups D and C were 263.73± 38.4 min and 251.7529.6 min, respectively (P = 0.008). Conclusion: IV infusion of dexmedetomidine significantly prolonged the duration of sensory and motor block of hyperbaric spinal bupivacaine with significant side effects.

Comparison of levobupivacaine and levobupivacaine with fentanyl in infraumbilical surgeries under spinal anaesthesia.

Background:Intrathecal opioids added to low dose local anesthetics in spinal anaesthesia intensifies sensory block without affecting sympathetic blockade. Aim was to evaluate the safety and efficacy of intrathecal levobupivacaine plain versus levobupivacaine plus fentanyl in infraumbilical surgeries.Materials and Methods:In a prospective randomized double blind study, 100 patients of American Society of Anesthesiologists grades I and II of either sex, 20–65 years of age were included after approval from the Ethics Committee. Informed consent was taken and patients were randomly divided into two groups of 50 each, to receive either 2 ml of 0.5% isobaric levobupivacaine (group L) or 2 ml of 0.5% isobaric levobupivacaine + 25 μg fentanyl (group LF) intrathecally. Patients were monitored for sensory and motor block characteristics, postoperative analgesia, haemodynamics and side effects and complications for 24 h.Results:Onset of sensory block and time to maximum sensory block was rapid in group LF (4.8 ± 1.50 and 8.46 ± 1.87 min) as compared to group L (7.6 ± 1.46 and 15.80 ± 2.43 min) (P < 0.000). Maximum sensory block was T6 in group LF and T8 in group L. Maximum Bromage score was 2 in both groups but was achieved earlier in group LF (P < 0.000). Duration of sensory and motor block was significantly prolonged in group LF (270.98 ± 28.60 and 188.52 ± 9.81 min) as compared to group L (197.58 ± 11.20 and 152.76 ± 9.79 min). Total duration of analgesia was also prolonged in group LF (265.16 ± 26.18 min) as compared to group L (168.16 ± 11.08 min). Patients remained haemodynamically stable and side effects and complications were comparable in both groups. Data was analyzed using “Chi-square test” and “unpaired t-test.”Conclusion:Addition of fentanyl to levobupivacaine leads to early onset and prolonged duration of sensory and motor block as well as postoperative analgesia with stable haemodynamics and minimal side effects.

Head Elevation in Spinal-Epidural Anesthesia Provides Improved Hemodynamics and Appropriate Sensory Block Height at Caesarean Section.

PurposeWe aimed to determine whether head elevation during combined spinal-epidural anesthesia (CSE) and Caesarean section provided improved hemodynamics and appropriate sensory block height.Materials and MethodsForty-four parous women undergoing CSE for elective Caesarean section were randomly assigned to one of two groups: right lateral (group L) or right lateral and head elevated (group HE) position, for insertion of the block. Patients were positioned in the supine wedged position (group L) or the left lateral and head elevated position (group HE) until a block height of T5 to light touch was reached. Group HE was then turned to the supine wedged position with maintenance of head elevation until the end of surgery. Hemodynamics, including the incidence of hypotension, ephedrine dose required, and characteristics of the sensory blocks were analyzed.ResultsThe incidence of hypotension (16 versus 7, p=0.0035) and the required dose of ephedrine [24 (0-40) versus 0 (0-20), p<0.0001] were greater in group L compared to group HE. In group L, the time to achieve maximal sensory block level (MSBL) was shorter (11.8±5.4 min versus 20.1±6.3 min, p<0.0001) and MSBL was also higher than in group HE [14 (T2) versus 12 (T4), p=0.0015].ConclusionHead elevation during CSE and Caesarean section is superior to positioning without head elevation in the lateral to supine position, as it is associated with a more gradual onset, appropriate block height, and improved hemodynamics.