Maximum Level Of Sensory Blockade Research Articles

Comparison of Two Different Volumes of Epidural Normal Saline for Enhancing the Effects of Spinal Anesthesia in Adult Patients Undergoing Elective Lower Limb Surgeries: A Prospective Randomized Study

Background: The combined spinal-epidural (CSE) anesthesia technique gives a reliable subarachnoid block as well as the flexible epidural block. One of the modified technique of CSE is epidural volume expansion (EVE) in which normal saline or local anesthetic (LA) is instilled though epidural catheter leading to increase in level of sensory blockade. Aim of the study was to compare two different volumes of normal saline for enhancing the effects of spinal anaesthesia in adult patients undergoing elective lower limb surgeries.
 Methods: 90 patients were randomly divided into two group. Group A - 45 patients who were received intrathecal 2.0ml of 0.5% hyperbaric bupivacaine and epidural 10ml of 0.9% normal saline for EVE using CSE technique. Group B - 45 patients who were received intrathecal 2.0ml of 0.5% hyperbaric bupivacaine and epidural 15ml of 0.9% normal saline for EVE using CSE technique.
 Results: The demographic data were comparable in both groups. Significant difference was seen in total duration of sensory blockade between group A (192.11±9.80) and group B (Mean ± SD 215.33±17.57minutes) (p<0.0001). Total duration of motor blockade was longer in group B (Mean± SD: 181.91± 16.42) as compared to group A (Mean ± SD: 162.48 ± 9.35 minutes) (p<0.0001).
 Conclusion: We conclude that epidural volume expansion (EVE) with 15 ml epidural normal saline was associated with faster onset, higher level and early achieve maximum level of sensory blockade, longer two segment regression time, early onset and longer duration of motor blockade as compared to EVE with 10 ml epidural normal saline.

Comparative Evaluation of Efficacies of Clonidine and Dexmedetomidine as an Adjuvant to Intrathecal Hyperbaric 0.5% Bupivacaine in Patients Scheduled for Elective Lower Limb Surgeries

Background and Aim: Several adjuvants have been utilized to enhance the standard of analgesia over the time of post-surgery. We have undertaken this study to evaluate and compare the efficacies of clonidine and dexmedetomidine as an adjuvant to intrathecal hyperbaric 0.5% bupivacaine in patients scheduled for elective lower limb surgeries. Material and Methods: The present study is blinded randomized case control done in the department of the Emergency Medicine in the medical college and associated hospital. All patients undergoing elective lower limb surgery were included for the study. After obtaining the consent letter signed from the patients; total of 180 patients were included in the study. Patients were divided into 3 groups: Group A (control group): received 15mg of 0.5% hyperbaric bupivacaine with 0.5 ml normal saline. Group B (clonidine group): received 15mg of 0.5% hyperbaric bupivacaine with 50µg clonidine. Group C (dexmedetomidine group): received 15mg of 0.5% hyperbaricbupivacaine with 5µg dexmedetomidine. Various parameters were examined were: Onset of sensory blockade and motor blockade, Maximum level of sensory blockade and time taken for the same, Maximum level of motor blockade and time taken for the same. Results: There is no clinical significance between group B and group C regarding mean time taken for onset of sensory blockade. The mean duration of analgesia is 194 ± 26.98 mins in group A (controlgroup), 346.37 ± 32.16 mins in group B (clonidine group) 373.37 ± 38.17 mins in group C (dexmedetomidine group). There is a statistically highly significant difference between group A and group B. Conclusion: The supplementation of bupivacaine with dexmedetomidine 5 μg or clonidine 50 μgin spinal anaesthesia produces significant shorter onset of motor and sensory block with longer duration of sensory and motor block when compared to bupivacaine alone.

Effect of Adding Magnesium Sulphate to Epidural Bupivacaine Compared to Addition of Fentanyl in Patients undergoing Lower Limb Orthopedic Surgery under Combined Spinal Epidural Anathesia

Abstract Background The use of opioids in intrathecal or epidural anesthesia has become popular to optimize postoperative analgesia. However, opioid-induced side effects, such as respiratory depression, nausea, vomiting, urinary retention and pruritus, limit their use. Objectives The purpose of this study was to assess the postoperative analgesic requirements and the analgesic effect of adding magnesium sulphate to epidural bupivacaine compared to addition of fentanyl in patients undergoing lower limb orthopedic surgery under combined spinal epidural anathesia. Patients and Methods After approval of ethical committee in our study and obtaining written informed consent from eligible patients the study was conducted on 60 patients classified to ASA I and II scheduled for lower limb orthopedic surgery. The study presents double armed randomized interventional prospective study including patients allocated into two equal groups each consists of 30 patients. Group (A): patients received magnesium sulphate added to bupivacaine in epidural, Group (B): patients received fentanyl added to bupivacaine in epidural Results The results of their study showed that the maximum level of sensory blockade was significantly higher in the combined fentanyl with magnesium group as compared with fentanyl group alone and magnesium sulphate group alone. The duration of sensory blockade of the combined fentanyl and magnesium group was significantly prolonged as compared to the other two groups as for the other two group the difference in the blockade duration was insignificant Conclusion We concluded that either magnesium sulfate (75 mg) combined with (10 ml) 0.25% Bupivacaine or fentanyl (1 µg/kg) combined with (10 ml) 0.25% Bupivacaine in combined spinal epidural improves intraoperative analgesia and prolongs early postoperative analgesia in lower limb orthopedic surgeries. The duration of analgesia was more prolonged in magnesium sulphate group than in the fentanyl group and this difference was statistically significant.

A comparative Study of Epidural Ropivacaine 0.75% Alone and Ropivacaine with Dexmedetomidine for Lower Limb Surgeries

Background: Ropivacaine in epidural anaesthesia provides good analgesia, lesser motor blockade and cardiac stability. Addition of adjuvants like dexmedetomidine provides longer duration of analgesia, prolonged motor blockade with adequate sedation. Our study compares Ropivacaine alone and in combination with dexmedetomidine on block characteristics, postoperative analgesia and sedation. Methods: Following institutional ethical committee clearance and patients informed written consent Sixty patients (ASA I, II) aged 18 - 60 years of either sex posted for elective lower abdominal and lower limb surgeries were randomized into two groups, Group R and Group RD. The patients in group R received 19ml of 0.75% Ropivacaine with 1ml of normal saline and the patients in group RD received 19ml of 0.75% Ropivacaine with dexmedetomidine (1μg/kg) respectively. Both groups were compared with respect to onset and duration of sensory and motor blockade, intensity of motor blockade using modified bromage scale, maximum level of sensory blockade, sedation score, hemodynamic variations and adverse effects. Results: The mean onset of sensory and motor block in group R was 11.36±3.03& 16.63±2.70 minutes, in group RD was 6.80±1.30 & 12.10±1.63 minutes respectively. Duration of sensory and motor block in Group R was 199.60±23.4 & 150±17.64 minutes and in group RD was 296.30±21.12 & 235.00±17.64 minutes respectively. The patients in Group RD had rapid onset of action, significant prolongation of motor and sensory block, intense motor block, better sedation score and postoperative analgesia (p<0.05).No significant hemodynamic changes in either group. Conclusion: There is a clear synergism between dexmedetomidine and ropivacaine compared with ropivacaine in epidural anaesthesia

A prospective randomised comparative study between 10 ml and 15 ml of normal saline for epidural volume expansion on 10mg of 0.5% hyperbaric bupivacaine spinal anesthesia for elective infraumbilical surgeries in adult patients

Introduction: The technique of combined spinal epidural (CSE) anaesthesia has become popular for patients undergoing elective infraumbilical surgeries where intraoperative prolonged and effective post-operative analgesia is required. CSE has the reliability of subarachnoid block as well as the flexibility of epidural block. The epidural volume expansion (EVE) technique is a modification of CSE in which the level of sensory analgesia obtained by subarachnoid block is increased by saline administered through the epidural catheter. Aims and Objectives: The present study was designed to compare different volumes of normal saline (10ml and 15ml) for epidural volume expansion on spinal anaesthesia with 10 mg (2 ml) of 0.5% hyperbaric bupivacaine for elective infraumbilical surgeries in adult patients with respect to sensory and motor block characteristics and haemodynamic stability. Materials and Methods: In this randomized, double blind, prospective study, ninety patients of ASA I and II of age group 18 – 59 years undergoing elective infraumbilical surgeries were randomly assigned into three groups namely group 0, group 10 and group 15. Combined Spinal Epidural technique was performed using double segment technique in lateral position in all the patients. Group 0 received 10 mg of 0.5% hyperbaric Bupivacaine intrathecally without EVE, group 10 received 10mg of 0.5% hyperbaric Bupivacaine followed by EVE with 10 ml of normal saline, group 15 received 10mg of 0.5% hyperbaric Bupivacaine followed by EVE with 15 ml of normal saline. Results: There were no statistically significant difference in the demographic data among the studied groups. Regarding block profile, the time of onset of sensory block was found to be statistically insignificant whereas a significant difference was noted among the three groups regarding maximum level of sensory blockade. Time to achieve maximum level of sensory blockade was observed to be longest in group 15 (mean ± SD: 4.76 ±0.72 minute

The Comparative Study of Epidural Anesthesia between Isobaric Ropivacaine 0.5% and Isobaric Bupivacaine 0.5% for Lower Abdominal Surgery.

Aim:The aim of the study was to compare the effectiveness of ropivacaine (0.5%) and bupivacaine (0.5%) in epidural neuraxial blockade for elective lower abdominal surgeries.Methods:The present study was conducted in sixty patients undergoing elective lower abdominal surgeries under epidural anesthesia who were included after satisfying the eligibility criteria. The patients were randomly divided into two groups. An epidural catheter was inserted in cephalad direction using Tuohy epidural needle at L2–L3 or L3–L4 with the help of loss of resistance to air technique. Twenty milliliter of the study drug was given, sensory blockade was tested using the pinprick method, and quality of motor blockade was assessed by the modified Bromage scale.Results:In our study, demographic data comparing age and sex show no statistically significant difference among both the groups. In our study, the mean time for the onset of sensory block consider at T10 in Group B was 10.05 ± 2.1 min and in Group R was 9.8 ± 1.8 min. Moreover, the mean time duration of sensory block in Group B was 5.56 ± 0.059 h and in Group R was 5.34 ± 0.073 h. The onset of motor block in Group B was 4.98 ± 1.07 min and in Group R was 5.28 ± 1.2 min, but the duration of motor block for Group B was 4.63 ± 0.39 h and for Group R was 3.53 ± 0.23 h, which is clinically and statistically significant. The maximum level of sensory blockade for Group B was T4 and for Group R was T5. The range of block in Group B was T10–T4 and in Group R was T10–T35.Conclusion:The onset of sensory block was comparable in both the group, but the duration of sensory block is shorter with ropivacaine compared to bupivacaine. The onset of motor blockade was comparable in both the groups, but the duration of motor blockade was also shorter and the degree of motor block was less intense with ropivacaine compared to bupivacaine.

EXPERIENCE OF THE USE OF LEVOBUPIVACAINE FOR SPINAL ANESTHESIA IN UROLOGICAL INTERVENTIONS

The prospective study included data obtained during the surgical treatment of 55 urological patients. In the X10 group (n = 25) for spinal anesthesia used 2 ml of a 0.5% isobaric solution of levobupivacaine (10 mg), in the X15 group (n = 30) - 3 ml of a similar solution (15 mg). Results. The time to the motor blockade of Bromage I in the study groups was 9 ± 3 min versus 8 ± 3 min, p = 0.154, to Bromage III - 18 ± 7 min versus 13 ± 3 min, p = 0.001. In group X10 motor blockade did not develop in 1, reached only the first degree - in 1, only the second degree - in 5 patients. In the X15 group, all patients underwent motor blockade of the third degree, except for 2 patients, in whom block reached only the second degree. The maximum level of sensory blockade in the group X10 was Th8, X15 - Th9. In the X10 group, the upper blockade level, not exceeding Th11, was observed in 11 (44%), and in the X15 group - in 17 (57%) patients. In 6 cases of the X10 group (24%) and 5 cases of the X15 group (17%) had to add sedation or general anesthesia. The duration of motor blockade before the beginning of recovery was 163 ± 57 min versus 195 ± 66 min, p = 0.076, until the motor block regressed completely - 219 ± 66 min versus 290 ± 90 min, p = 0.002. Arterial hypotension was observed in one patient group X10 (4%) and 0 group X15, bradycardia in 7 (28%) and 7 (23%) patients, respectively. There were no transient neurologic symptoms in any cases. Conclusions. Spinal anesthesia with isobaric levobupivacaine was characterized by a slow development of the complete motor block, unpredictably low upper level of the sensory blockade and a long-lasting motor block. It can be used in patients with high risk of arterial hypotension or transient neurologic symptoms, provided sufficient time is available before the operation, the possibility of sedation and / or the addition of general anesthesia.

A Comparative Study for the Analgesic Efficacy and Safety Profile of Fentanyl versus Clonidine as an Adjuvant to Epidural Ropivacaine 0.75% in Lower Abdominal Surgeries.

Context:Different adjuvants are coadministered with local anesthetics to improve the speed of onset and duration of analgesia, and to reduce the dose, the selection of which is often left to the choice of an anesthesiologist.Aim:The aim of this study was to compare the analgesic efficacy and safety profile of fentanyl and clonidine as an adjuvant to epidural ropivacaine anesthesia.Setting and Design:With institutional ethical committee clearance, a prospective, randomized, placebo-controlled double-blind clinical study was conducted at Vivekananda Polyclinic and Institute of Medical Sciences, Lucknow.Material and Methods:Two groups with thirty patients each were randomly allocated to receive 15–20 ml of 0.75% ropivacaine with 75 μg clonidine or 15–20 ml of 0.75% ropivacaine with 75 μg fentanyl, respectively. Block characteristics such as onset of analgesia, maximum level of sensory blockade, complete motor blockade, hemodynamic, time to two-segment regressions, time for rescue analgesia, time to complete motor recovery, and side effects were analyzed.Results:Results showed that the onset of blockade is faster when fentanyl is used as additives. Time for two-segment regression was earlier in fentanyl group but time for rescue analgesia was longer in clonidine group.Statistical Analysis:Two groups were compared by Student's t-test and Chi-square test; ANOVA and significance of mean difference bet were done by Newman–Keuls test.Conclusion:Addition of clonidine to epidural ropivacaine provides superior analgesia than the addition of fentanyl to epidural ropivacaine without much difference in side effect profile.

Comparison of Postoperative Pain After Epidural Anesthesia Using 0.5%, 0.75% Ropivacaine and 0.5% Bupivacaine in Patients Undergoing Lower Limb Surgery: A Double-Blind Study.

Background:Ropivacaine (S (-)-1-propyl-2”, 6”; pipecoloxylidide hydrochloride) a newer long-acting amide local anesthetic has various clinical and pharmacokinetic advantages over bupivacaine.Aims:The aim of this study is to compare the onset as well as the duration of sensory block, hemodynamic variables, and postoperative analgesia with 0.5%, 0.75% ropivacaine and 0.5% bupivacaine after epidural anesthesia for lower limb orthopedic surgery.Patients and Methods:Sixty American Society of Anesthesiologists I and II patients scheduled for lower limb orthopedic surgery were enrolled into this randomized, double-blind study. Epidural block was obtained with 15 ml of 0.5% ropivacaine (Group I), 15 ml of 0.75% ropivacaine (Group II), and 15 ml of 0.5% bupivacaine (Group III). The onset time, duration, and maximum level of sensory blockade achieved, as well as hemodynamic parameters and any side effects, were noted and treated accordingly. Postoperative monitoring for pain by visual analog scale (VAS) was done every 2 hourly for 24 h and transient neurological symptoms for 72 h.Statistical Analysis:Chi-square test for nonparametric data and ANOVA for parametric data.Results:Demographic characteristics were similar among groups. The onset of sensory block varied from 22.35 ± 2.74 min (mean ± standard deviation [SD]) in Group I, 16.95 ± 2.96 min (mean ± SD) in Group II, and 19.70 ± 2.25 min (mean ± SD) in Group III. The mean duration of analgesia in Group III (157 ± 14.90 min)was comparable to Group II (149 ± 16.51 min) but it was significantly more than Group I (141.5 ± 17.55 min). Postoperatively, VAS scores were higher in Group I patients who required more number of postoperative epidural top-ups with tramadol. Adverse effects were noted and treated accordingly. There was no incidence of transient neurological symptoms postoperatively.Conclusion:Both ropivacaine and bupivacaine provided effective epidural anesthesia for lower limb surgery. Postoperative pain was less with 0.5% bupivacaine and 0.75% ropivacaine as compared to 0.5% ropivacaine.

A comparative study of dexmedetomidine and fentanyl as an adjuvant to epidural bupivacaine in lower limb surgeries

Background: Epidural anesthesia is the most commonly used technique for inducing surgical anesthesia and postoperative analgesia in patients undergoing lower limb surgeries. Fentanyl as an adjuvant to epidural local anesthetic has been used for a long time. Dexmedetomidine is a potent and highly selective α-2-adrenoceptor agonist with analgesic potency. Aim: The aim of the present study was to compare the effect of dexmedetomidine and fentanyl as an adjuvant to epidural bupivacaine in lower limb surgeries. Materials and Methods: Sixty patients belonging to the American Society of Anesthesiologists' Grade I or II who were undergoing lower limb surgery were randomly divided into two groups. Group BD: received epidural study solution of 38 ml of 0.25% bupivacaine hydrochloride + 1 ml of 100 μg dexmedetomidine + 1 ml of normal saline. Group BF: received epidural study solution of 38 ml of 0.25% bupivacaine hydrochloride + 2 ml of 100 μg fentanyl. Onset and maximum level of sensory blockade, time to attain maximum sensory level, time to complete motor blockade, time for two-segment regression, duration of analgesia and motor block, heart rate, and blood pressure were observed. Pain and sedation were assessed by numerical rating scale and Ramsay Sedation Scale, respectively. Data were recorded and statistically analyzed. Results: The onset of sensory blockade and time to attain maximum sensory level in Group BD were earlier than that of Group BF (P < 0.001). Duration of analgesia and motor blockade in Group BD were significantly more than that of Group BF (P < 0.001). Postoperative visual analog scale was reduced statistically significantly in Group BD (P < 0.001). Conclusion: Dexmedetomidine as an adjuvant to epidural bupivacaine is a better alternative to fentanyl with higher analgesic property.

Comparison of Levobupivacaine and Clonidine with Bupivacaine and Clonidine in Spinal Anaesthesia for Lower Segment Caesarean Section

Comparison Of Levobupivacaine And Clonidine With Bupivacaine And Clonidine In Spinal anaesthesia ForLowerSegmentCaesareanSection Introduction: Intrathecal LevoBupivacaine is having similar clinical profile with less cardio-toxicity than Bupivacaine is used commonly for LSCS. Clonidine as an additive to LA provides effective, prolonged and dose dependent analgesia. In this study we compared effect of intrathecal Clonidine 30 μg and 0.5% isobaric Levobupivacaine 9 mg with Clonidine 30 μg and 0.5% hyperbaric Bupivacaine 9 mg for LSCS. Material and method : In this study we want to compare onset, degree, maximum sensory level achieved, time required to achieve the maximum level of sensory blockade, duration of effective sensory blockade and onset and degree of effective motor blockade ,its cardiac effect and effect on APGAR score of baby after intratheacal Clonidine 30 μg as an adjuvant to intrathecal 0.5% isobaric Levobupivacaine 9 mg and 0.5% hyperbaric Bupivacaine9mg. Observations:The mean time for the onset of motor blockade in patients in group B was 1.90 ± 0.54 min and in group L was 2.15 ± 0.47 min. Mean time required for maximum motor blockade was 4.70 ± 0.65 min for group B and 4.30 ± 0.59 min for group L. Time of onset of analgesia at T6 was 6.40 ± 0.81 in group B and 6.70± 0.84 min in L group. Time requited to achieve maximum level of analgesia was 7.20 ± 1.21min in group B and 7.33 ± 1.26 min in group L. Bradycardia was statistically significant in patients of group B as compared to that in group L. Two dermatome regression in group B was at 158.27 ± 5.01 min and in group L it was at 157.83 ± 3.49 min. The first rescue analgesic required in group B was at 167.68 ± 3.84 min and in group L was at 165.73 ±4.65min. Conclusion:We observed that that isobaric Levobupivacaine with Clonidine has got comparable pharmacokinetic in onset and offset of sensory and motor block, less cardiovascular side effects, good intraoperative and postoperative analgesia without sedation and adverse effect on Apgar score so we conclude that Levobupivacaine with Clonidine is a better choice in LSCS than Bupivacaine with Clonidine.

English

BACKGROUND: Hemodynamic disturbance and uteroplacental hypoperfusion can occur due to Aortocaval Compression (ACC) in parturient which are further aggravated by SAB. Incidence of maternal hypotension due to cephalad spread of local anesthetic (LA) in subarachnoid space and ACC by gravid uterus; both these factors influenced by parturient's posture during and immediately after SAB, we tested the hypothesis that keeping parturient in sitting position for five minutes after SAB, likely limit the spread of LA, thus reduce the incidence of hypotension and Intraoperative ephedrine requirements. AIMS AND OBJECTIVES: to determine the effects of making parturient sit up for five minutes after SAB, that would have on sensory block height, incidence of hypotension and ephedrine requirements. Secondarily, to study duration of postoperative analgesia. MATERIALS AND METHODS; Single blinded randomized comparative study having 30 parturients in each group CS and CL were allocated to receive 2ml of hyperbaric bupivacaine with 0.4ml NS, Or 20 µgm fentanyl added to 2 ml hyperbaric bupivacaine group FS or FL, either in sitting group (made to sit for 5 min. post SAB before supine) or in lying group, made supine immediately. The maximum level of sensory blockade achieved and monitoring of heart rate, noninvasive blood pressure, respiratory rate and oxygen saturation were done every 2 min for first 10 min then at 15 min interval for remainder of operation. Postoperatively, onset of pain was noted. STATISTICAL ANALYSIS: By using descriptive and inferential statistics using unpaired t-test, chi Square test, and Mann-Whitney U test. The Software used was SPSS 17.0 version and Graph Pad Prism 5.0. Analyzed data was expressed as mean ± SD for continuous variables and number (%) for categorical variables. P value < 0.05 was considered statistically significant RESULTS: Sitting Groups had lower sensory block height than lying Groups; also required less ephedrine. Duration of postoperative analgesia was prolonged in both the fentanyl Groups. CONCLUSION: prolonged sitting position after spinal anesthesia not only limit the spread of LA, producing lower sensory block height but also reduces the incidence of

A comparison of spinal anesthesia characteristics following intrathecal bupivacaine or levobupivacaine in lumbar disc surgery

While bupivacaine is the most frequently used local anesthetic for spinal anesthesia, use of levobupivacaine in clinical practice has advanced recently. The aim of our study was to compare the clinical and anesthetic effects of isobaric bupivacaine and isobaric levobupivacaine when administered intrathecally in patients undergoing lumbar disc surgery. ASA I-III, 60 patients were enrolled in this study. Only patients with unilateral single-level (L4-5) lumbar disc hernia were selected and operated in each group and all were operated by the same surgeon. Patients were randomized into two groups, as group B (n = 30): 15 mg 0.5% isobaric bupivacaine, or group L (n = 30): 15 mg 0.5% isobaric levobupivacaine received intrathecally. The level of sensory block dermatome, degree of motor block, intraoperative sensory and motor block characteristics, and postoperative recovery times of spinal anesthesia were evaluated. The satisfaction scores of the surgeon and patients, intraoperative hemodynamic changes, intraoperative and postoperative complications were recorded. The maximum level of sensory blockade was significantly higher in the levobupivacaine group (group L 7 ± 1.63, group B 8.6 ± 1.76 thoracic dermatome, p < 0.05). There was no significant difference in the onset time of sensory (group L 6 ± 3 min, group B 9 ± 4 min) and motor (in group L 7 ± 3 min, in group B 10 ± 4 min) blockade (p > 0.05). There was no significant difference between the groups regarding duration of operation (group L 49 ± 7.3 min, group B 52 ± 8.1, p > 0.05). Recovery times of sensory (175 ± 57 min) and motor (216 ± 59 min) blockade were significantly shorter in the levobupivacaine group (p < 0.05). Mobilization was also earlier in the levobupivacaine group (339 ± 90 min, p < 0.05). Patients' satisfaction and intraoperative, postoperative complications were similar between the two groups. Our results showed that block recovery time was shorter in the levobupivacaine group, this may be a disadvantage for longer operative procedures. But with proper patient selection this can be eliminated. Recovery time was shorter in levobupivacaine group. Therefore, postoperative neurological examination can be done earlier. In addition, early mobilization can be an advantage for postoperative recovery.

Comparison of Bupivacaine and Normal Saline for Epidural Top-up on Sensory Blockade Level during Combined Spinal Epidural Anesthesia

Background: An increase in the maximum level of sensory blockade by epidural 'top-up' in combined spinal epidural anesthesia may be explained by two mechanisms; a volume effect, compressing the dural sac, and a local anesthetic effect. This study was undertaken to investigate the relative importance of these factors. Methods: Eighty patients about to undergo lower limb surgery under combined spinal epidural anesthesia were randomly assigned to four groups. Using the needle-through-needle technique, all patients received a subarachnoid injection of 8 mg of heavy bupivacaine through an epidural catheter. At 30 minutes after subarachnoid injection, an epidural top-up was given according to a randomization code. Experimental groups received 10 ml of saline, 10 ml of bupivacaine 0.25%, or 10 ml of bupivacaine 0.5%. The control group received no epidural top-up. The level of sensory blockade was checked by using the pinprick test at 5, 10, 15, 20, 25 and 30 minutes after subarachnoid injection, and at 5, 10, 15, 20, 25 and 30 minutes after epidural top-up. Blood pressure, heart rate and the incidence of side effects soh as hypotension, bradycardia, nausea, and high block were analyzed. Results: There was no significant difference in maximum level of sensory block among the 10 ml saline, 10 ml bupivacaine 0.25% or 10 ml bupivacaine 0.5% treated groups during epidural phase. Although blood pressure and heart rate were decreased, there were no differences among experimental groups during epidural phase. The most common side effect during combined spinal epidural anesthesia was hypotension. The incidence of bradycardia and high sensory block (above T4 dermatome level) was similar among the groups. Conclusions: After the maximum level of sensory blockade due to subarachnoid injection has been established, an epidural top-up with 10 ml of saline or 10 ml of either 0.25% or 0.5% bupivacaine did not significantly increase the level of subarachnoid block in patients with lower extremity surgery. The author concludes the there were no differences among groups with regard to the volume effect and local anesthetic effect in terms of the sensory blockade level during the epidural phase. However, mod pressure and heart rate in the epidural top-up groups reduced with operation time.

Effect of Speed of Injection on the Maximum Sensory Level for Spinal Anesthesia Using Plain Bupivacaine 0.5% at Room Temperature

Background and Objectives. The aim of this study was to investigate if a ten-fold difference in speed of injection of a plain solution of bupivacaine 0.5% at room temperature into the subarachnoid space would result in a temperature-dependent change in baricity large enough to be reflected in a significant difference between the maximum levels of sensory blockade. Methods. In this prospective study, 40 male patients were randomly assigned to one of two groups. Group 1 patients received 3 ml plain bupivacaine 0.5% (20-22°C) with the speed of injection as fast as possible. Group 2 patients received 3 ml plain bupivacaine 0.5% (20-22°C at a rate of 0.05 ml/sec. Thirty minutes after subarachnoid injection the maximum level of sensory blockade was determined by pinprick in the anterior axillary line by a blinded observer. Results. The mean maximum level of sensory blockade in patients of group 1 was T7.5 (median, T7; range, T3-12) and in group 2 patients T6.4 (median, 5.5; range, T3-11), the difference not being statistically significant (p > 0.05). Conclusions. There is no clinically relevant influence on the maximum level of sensory blockade when bupivacaine 0.5% at room temperature is injected with a ten-fold difference in speed.

Influence of temperature of bupivacaine on spread of spinal analgesia

A prospective, randomised study was performed to investigate the influence of temperature on sensory blockade in spinal anaesthesia. Three ml of plain bupivacaine 0.5% were injected intrathecally at either 4 degrees C, room temperature, or 37 degrees C. There were 10 patients in each group, who were kept sitting for 2 minutes after injection. The maximum level of sensory blockade was significantly higher (p less than 0.01) in the group who received the solution adjusted to 37 degrees C, and variability of level was smaller (p less than 0.05). Time to two-segment regression was shorter in the 37 degrees C group than in the 4 degrees C group (p less than 0.05). Hypotension required administration of ephedrine more often in the 37 degrees C group (p less than 0.05). It is concluded that the use of plain bupivacaine 0.5% adjusted to 37 degrees C results in a higher and more predictable sensory blockade.

Spinal Anesthesia with Plain Bupivacaine 0.5%

Onset (defined as the time between injection and achievement of the highest level of sensory blockade), duration, and regression of sensory and motor blockade after the intrathecal administration of 3 mL plain bupivacaine 0.5%, previously equilibrated to either 37 degrees C or 20 degrees C, were studied in two groups of 20 patients. In patients receiving the solution equilibrated to 37 degrees C, the maximum level of sensory blockade was significantly higher (T 4.6 vs T 7.5), variability was smaller (SEM 0.33 vs 0.58), and duration of the sensory level of blockade at or above T 6, T 8, and T 10 was significantly longer (56 min vs 20 min, 101 min vs 59 min, and 131 min vs 77 min, respectively). There were no significant differences with regard to onset of sensory and motor blockade or either the time needed both for the sensory level of blockade to regress two segments from its highest level and to the first lumbar segment, or the duration of complete motor blockade of the lower limbs. It is concluded that the intrathecal administration of a bupivacaine solution previously equilibrated to 37 degrees C as compared with a solution injected at room temperature results in a higher, more predictable maximum sensory level of blockade with longer duration at or above T 6, T 8, and T 10.