Isobaric Spinal Anesthesia Research Articles

Effects of Hyperbaric and Isobaric Bupivacaine on Hemodynamic Profiles and Block Characteristics Among Parturients Undergoing Elective Cesarean Section Under Spinal Anesthesia: A Randomized Controlled Trial.

Cesarean section (CS) is a surgical procedure where the baby is delivered through incisions made in the abdomen and uterus. Bupivacaine is a widely recognized local anesthetic available in different baricity and it is frequently used for spinal anesthesia. The baricity of bupivacaine impacts hemodynamic profiles and block characteristics. To compare the effects of hyperbaric and isobaric bupivacaine on hemodynamic profiles and block characteristics among parturients undergoing elective cesarean section under spinal anesthesia at Dilla University Referral Hospital. 64 pregnant mothers scheduled for elective cesarean section under spinal anesthesia were randomly assigned to two groups: Group A received a dose of 12.5 mg of isobaric bupivacaine (n = 32), Group B received a dose of 12.5 mg of hyperbaric bupivacaine (n = 32). Prior to conducting the study, the necessary ethical approvals were obtained. For comparing numerical variables between the two groups, the independent Sample t-test or Mann-Whitney U-test was employed as needed. Repeated measurements were analyzed using mixed ANOVA. Categorical variables were assessed using either the chi-square test or Fisher's exact test. Statistical significance was set at P < 0.05, with a power of 90%. The mean Systolic Blood Pressure (SBP), Diastolic Blood pressure (DBP), and Mean Arterial Blood Pressure (MAP) showed significant decrement in the group receiving isobaric spinal anesthesia compared to those receiving hyperbaric bupivacaine. The decrement was observed from the 6th to 30th minute (p<0.05). Furthermore, the hyperbaric group had a faster onset time for achieving the maximum sensory block, with a median time of 3 (1) min compared to 4 (2) mins in the isobaric group (p<0.001). We conclude that hyperbaric bupivacaine provides stable intraoperative hemodynamic parameters and an earlier onset of block than isobaric bupivacaine. Therefore, we recommend clinicians to use hyperbaric bupivacaine for cesarean delivery.

To Compare Isobaric Thoracic Spinal Anesthesia Versus General Anesthesia in Laparascopy Cholecystectomy

Background: The laparoscopic cholecystectomy procedure is typically carried out under general anesthesia, but regional techniques, such as low thoracic isobaric spinal anesthesia, have been used to manage patients with significant medical problem like coexisting systemic disease, who are deemed to be high risk in general anesthesia. Segmental spinal anesthesia has great outcomes in terms of post-operative discomfort, the need for analgesics, relatively fewer complications, and shorter hospital stays. Thus the aim of this study to avoid and minimize the risk of general anesthesia who does not have any significant comorbidity. So it might be a substitute for a standard laparoscopic cholecystectomy. Material and Methods: Total 60 adult patient with ASA1 &amp; I I, 18-60 years, with normal coagulation profile, is divided into 2 groups. Group IS (Isobaric) - given 2.5 ml of isobaric preservative free bupivacaine 0.5% (levobupivacaine) + 0.5 mg of Fentanyl at T9-T10/T10-T11 into sub arachnoid space. Group GA – given general anesthesia using propofol, fentanyl citrate and atracurium besylate. After intubation, ventilation was controlled and balanced anesthesia was continued with isoflurane. After completion, neuromuscular block was anatagonized neostigmine methylsulfate and glycopyrrolate at the end of surgery. Results: Isobaric spinal anesthesia showed good control in intraoperative as well as postoperative pain control as compared to general anesthesia. In few patients, there were minor degrees of nausea, vomiting, abdominal pain, shoulder pain, patient anxiety or itchng which were treated with standard medication like fentanyl and midazolam. All patients can resume oral intake on the day of surgery. Conclusions: In conclusion, this study provide evidence that segmental spinal anesthesia can be used in place of general anesthesia in healthy individuals also.

Optimum compatibility of ropivacaine and sufentanil for isobaric spinal anesthesia in caesarean section

Objective To investigate the optimum compatibility of ropivacaine and sufentanil for isobaric spinal anesthesia in caesarean section. Methods A total of 160 nulliparous parturients who were at full term with a singleton fetus, of American Society of Anesthesiology physical status Ⅰ or Ⅱ, scheduled for elective caesarean section under subarachnoid block, were divided into 4 groups (n=40 each) using a random number table method: 1% ropivacaine 1.5 ml (15 mg)-normal saline 3.5 ml group (group A), 1% ropivacaine 1.2 ml (12 mg)-sufentanil 0.5 ml (5 μg)-normal saline 3.3 ml group (group B), 1% ropivacaine 1 ml (10 mg)-sufentanil 0.5 ml (5 μg)-normal saline 3.5 ml group (group C), and 1% ropivacaine 0.8 ml (8 mg)-sufentanil 0.5 ml (5 μg)-normal saline 3.7 ml group (group D). Drugs were injected in cephalad direction at a rate of 0.1 ml/s.The upper spread of sensory block, degree of motor block, abdominal muscle tension, traction response, requirement for atropine and ephedrine and neonatal Apgar scores were recorded. Results Neonatal Apgar scores were all within the normal range.A, B and C groups had similar upper spread of sensory block which was higher than that in group D. The onset time of block was significantly prolonged, and the requirement for atropine and ephedrine was increased in group A as compared with B, C and D groups (P 0.05). The requirement for supplemented epidural local anesthetics was 30% (12 cases) in group D. The recovery time to ambulation was significantly shorter in C and D groups than in A and B groups(P 0.05). Conclusion One percent ropivacaine 1 ml (10 mg)-sufentanil 0.5 ml (5 μg)-normal saline 3.5 ml is the optimum compatibility of ropivacaine and sufentanil for isobaric spinal anesthesia in caesarean section. Key words: Amides; Sufentanil; Anesthesia, spinal; Cesarean section

Eficácia e efeitos hemodinâmicos da anestesia raquidiana com ropivacaína isobárica, hipobárica ou hiperbárica em cães anestesiados com isofluorano

RESUMO: O presente estudo objetivou avaliar a anestesia raquidiana com ropivacaína em cães alterando a baricidade do anestésico local, investigando as alterações hemodinâmicas e complicações. Foram utilizados seis cães, Beagle, 4 anos, submetidos a anestesia inalatória com isofluorano e aos tratamentos: Ghipo = anestesia raquidiana hipobárica (0,5 mL NaCl 0,9% + 0,5 mL ropivacaína 0,75%); Giso = anestesia raquidiana isobárica (0,5 mL NaCl 1,53% + 0,5 mL ropivacaína 0,75%); Ghiper = anestesia raquidiana hiperbárica (0,5 mL glicose 10% + 0,5 mL ropivacaína 0,75%). Após indução anestésica e manutenção com isofluorano, os animais foram posicionados em decúbito lateral direito para a passagem de um cateter de artéria pulmonar pela veia jugular esquerda. Após esse procedimento, a punção subaracnóide foi realizada entre L5-L6 com uma agulha espinhal 22G, seguida da administração de 1 mL de anestésico local em 1 min. Os animais foram mantidos por 60 minutos anestesiados em decúbito ventral. A FC, f, PAM, DC, PAPm e TºC apresentaram aumento progressivo em todos os grupos enquanto que a PCPm, apenas no GHIPO, aumentou ao longo de todos os momentos. O IRPT no GISO apresentou valores significativamente superiores no M1, M5 e M10 comparado aos demais grupos, exceto no M5, em que o GISO diferiu somente do GHIPER. O IRVP no GISO aumentou no M5 em comparação ao MB. Foram observados efeitos adversos como déficit motor unilateral, atonia vesical, excitação, dor aguda e quemose. De acordo com os dados obtidos no presente estudo pode-se concluir que os animais que receberam anestesia raquidiana com as soluções hiperbárica e isobárica apresentaram maior bloqueio motor comprovando que a baricidade influencia diretamente o tipo de fibra a ser bloqueada. A utilização de solução isobárica resulta em um bloqueio misto (motor e sensitivo). As alterações hemodinâmicas descritas na literatura como, bradicardia e hipotensão, não puderam ser evidenciadas neste estudo embora o volume de anestésico tenha sido baixo associado a influência dos efeitos do isofluorano. Em relação às complicações evidenciadas, sugere-se acompanhamento pós-anestésico dos animais submetidos à anestesia raquidiana a fim de que quaisquer alterações possam ser identificadas precocemente e tratadas.

Comparison of isobaric spinal anesthesia and caudal anesthesia in anorectal surgery

目的 探讨等比重腰麻与骶麻在肛肠手术中的麻醉效果。 方法 选择择期或急诊肛肠手术患者50例，按照数字表法将患者随机分为等比重腰麻组(A组)和骶麻组(B组)，每组25例。比较两组患者麻醉起效时间及麻醉效果优良率，并观察术中直肠牵拉反应、局麻药中毒、术后尿潴留等并发症发生率。 结果 A组麻醉起效时间为(5.0±0.3)min，麻醉效果优良率为96.0%，直肠牵拉反应、局麻药中毒、术后尿潴留等并发症发生率分别为0.0%、0.0%、12.0%；B组起效时间为(20.0±0.5)min，麻醉效果优良率为76.0%，三项并发症发生率分别为60.0%、8.0%和28.0%。两组麻醉起效时间比较差异有统计学意义(t＝21.324，P<0.05)，麻醉效果优良率比较差异有统计学意义(χ2＝6.246，P<0.05)，并发症发生率比较差异均有统计学意义(均P<0.05)。 结论 与骶麻相比，等比重腰麻是肛肠手术中比较理想的安全的麻醉方式。

A Comparison of the Effects of Preanesthetic Administration of Crystalloid Versus Colloid on Intrathecal Spread of Isobaric Spinal Anesthetics and Cerebrospinal Fluid Movement

Movement of the cerebrospinal fluid (CSF) is one of the most important factors in determining the intrathecal spread of isobaric spinal anesthetics. Preanesthetic administration of either crystalloid or colloid immediately before spinal anesthesia (preload) may result in different CSF pulsatile movement because of their different physical properties. We examined whether preload of crystalloid versus colloid may have different effects on the intrathecal spread of isobaric spinal anesthetics as a result of their different CSF dynamics regarding its pulsatile movement. In a clinical study of isobaric spinal anesthesia, patients were allocated into 1 of 2 groups according to preload with either crystalloid (n = 30) or colloid (n = 30) before spinal anesthesia with 0.5 isobaric tetracaine. The pulsatile movements of CSF at the L2-3 intervertebral space and midportion of the aqueduct of Sylvius were also examined by magnetic resonance images in healthy volunteers (n = 23) at 0, 30, and 60 minutes after administering either crystalloid or colloid. In the clinical study, the time to reach the peak sensory block level was delayed significantly in the crystalloid preload group (27.2 ± 17.8 minutes; P < 0.01) compared with the colloid preload group (13.9 ± 7.0 minutes). The median sensory block levels of the crystalloid preload group at 15 minutes (T10, P < 0.05) and 20 minutes (T9.5, P < 0.05) were significantly lower than those (T8, T7, respectively) of the colloid preload group. In the magnetic resonance imaging study, cranially directed CSF pulsatile movement decreased significantly at the L2-3 intervertebral intrathecal space at 30 minutes after crystalloid administration, but not after colloid administration. The CSF production rate significantly increased at 30 minutes (637 μL/min, P < 0.05) after crystalloid preload compared with the baseline measurement (448 μL/min), and then slightly decreased (609 μL/min) at 60 minutes. In the colloid preload group, the CSF production rate was not statistically significant compared with the baseline measurement (464, 512, and 542 μL/min at baseline, 30, and 60 minutes, respectively). Compared with a colloid preload, which may be comparable to the no-preload condition, crystalloid preload prolonged the time to reach the peak sensory block level in isobaric spinal anesthesia, which might have been caused by a significant decrease in CSF pulsatile movement. This attenuated CSF pulsatile movement in the crystalloid preload group might have resulted from significant increases of CSF production.

A Case Report of Transient Neurologic Symptoms (TNS) after Isobaric Spinal Anesthesia with 0.5% Bupivacaine

A Case Report of Transient Neurologic Symptoms (TNS) after Isobaric Spinal Anesthesia with 0.5% Bupivacaine

General and Spinal Anesthetic Experiences in a Patient Suspected with a History of Anaphylactic Reaction to Muscle Relaxants: A case report

The use of anesthetic agents may induce a certain number of anaphylactic and anaphylactoid reactions. Anesthesiologists, therefore, are well advised to develop a rational approach to minimize risks and evaluate patients who present with histories of allergic drug reactions in the perioperative period. A 63-year-old female patient was withdrawn from operation due to anaphylactic reaction or life-threatening anaphylactoid reaction occurred during induction of anesthesia and successfully resuscitated. Thereafter, skin prick test to anesthetics including intravenous agents such as thiopental, propofol, ketamine, fentanyl and lidocaine, and muscle relaxants such as succinylcholine, vecuronium and atracurium revealed positive reactions to all the tested muscle relaxants. Next anesthetic experience was done for microvascular decompression surgery without use of muscle relaxants. Two years later, she underwent lumbar laminectomy successfully under isobaric spinal anesthesia using tetracaine.

The Effect of Prehydration on Sensory Block Level in the Isobaric Spinal Anesthesia

Background: Even though the effect of prehydration on the spinal anesthesia-induced hypotension has not yet been concluded, prehydration prior to spinal anesthesia is recommended in order to reduce the incidence and severity of hypotension. We investigated the effects of prehydration on hemodynamic change during spinal anesthesia with isobaric 0.5% tetracaine. Methods: We prospectively performed this study on 96 patients who underwent elective transurethral surgery from October 2002 to January 2004. Patients were randomly allocated to receive either no prehydration or 10 ml/kg crystalloids administered over 10-15 min prior to spinal anesthesia. We compared dermatomal spreads of spinal anesthesia, hemodynamic parameters (blood pressure, heart rate), incidences of hypotension and bradycardia between two groups. Results: Hemodynamic parameters, incidences of hypotension and bradycardia showed no statistically significant differences during spinal anesthesia between two groups. There were statistically significant differences in the dermatomal spread of sensory levels between two groups from 5 to 90 min after spinal anesthesia. Sensory block levels in prehydration group were statistically lower than no prehydration group. Conclusion: We hypothesized that prehydration can be one of factors that influence on dermatomal spread of local anesthetics in isobaric spinal anesthesia. The difference of dermatomal spread between two groups may be caused by brain blood barrier (BBB)-freely passing crystalloids, which may influence on the volume and density of cerebrospinal fluids. To verify this phenomenon found in our study, further investigation is still warranted.

Comparative Study of Isobaric Bupivacaine Spinal Anesthesia in the Supine and Prone Positions

Background: Isobaric bupivacaine has same baricity as cerebrospinal fluid and therefore, so it remains at the level of injection. But, the risk of high spinal anesthesia exist, because increased intrathecal pressure is possible in prone position as isobaric bupivacaine has mild hypobaricity at body temperature but is isobaric at room temperature. So, we studied the influence of the position of the blockade of spinal anesthesia in isobaric spinal anesthesia. Methods: We studied 26 patients undergoing elective surgery for which spinal anesthesia was considered appropriate. One group (the P group) were scheduled for surgery in the prone position with a frame (n = 13), the second group (the S group) were scheduled for surgery in the supine position (n = 13). Patients were injected with 12 mg of 0.5% isobaric bupivacaine at L3-4 in the lateral decubitus position with a 22 G spinal needle at the rate of 0.2 ml/sec. We then assessed anesthetic blockade level, heart rate, and blood pressure. Results: The height of the sensory block in the prone position group was at the 10th thoracic dermatome, whereas in the supine position this was at the 8th thoracic dermatome at 15 minutes. There was a little difference between the two groups, but this was insignificant statistically. Conclusions: Both the supine and the prone positions are suitable for isobaric spinal anesthesia with bupivacaine. Isobaric spinal anesthesia in the prone position with a frame is as safe as in the supine position. Spinal anesthesia with isobaric bupivacaine is considered to have a low risk of high spinal anesthesia and a low complication level in the prone position with a frame, as for the supine position.

Room A, 10/16/2000 2: 00 PM - 4: 00 PM (PS) Extent of Isobaric Spinal Anesthesia Influences the Timing of Regression and Hemodynamic Consequences of Spinal Block

<b>Room A, 10/16/2000 2: 00 PM - 4: 00 PM (PS) Extent of Isobaric Spinal Anesthesia Influences the Timing of Regression and Hemodynamic Consequences of Spinal Block</b>

The Direction of the Whitacre Needle Aperture Affects the Extent and Duration of Isobaric Spinal Anesthesia

URMEY, WILLIAM F.; STANTON, JENNIFER; BASSIN, PAMELA; SHARROCK, NIGEL E.; Silverman, David G. M.D. Author Information

Isobaric Spinal Anesthesia for Lumbar Disk Surgery

We appreciate the comments of Rung et al. concerning the use of isobaric bupivacaine 0.5% (10 mg) instead of hyperbaric 0.75% bupivacaine as a spinal anesthetic for lumbar disk surgery. The ability to preposition a patient, place the spinal, and allow it to set up during prepping and draping would indeed produce a moderate time savings in the operating room. Prior to our study, we also prepositioned some patients and used hypobaric tetracaine 0.25% (7.5-10 mg) as our spinal anesthetic. The quality of the spinal was good, and we also observed a good time savings. However, in a few patients, we obtained a poor sensory level and, in some, an altogether failed block. These patients eventually had to be turned supine and placed under general anesthesia, which caused significant time delay and cost. Thus, for the present study, we decided to allow the spinal to set up prior to turning to avoid any problems and loss of time should the spinal fail. It would be interesting to note whether Rung et al. have had failed spinals while using their isobaric technique and, if so, whether they would repeat the spinal or turn the patient supine and induce general anesthesia. Rung et al. also state that the incidence of a high spinal level is less with isobaric spinal anesthesia compared with a hyperbaric technique. There is support in the literature for this claim [1]. It would be interesting to know their incidence of intraoperative hypotension compared with sensory spinal level. Our spinal levels rarely were higher than T8, and our incidence of hypotension was no different from that during general anesthesia. For lumbar diskectomies in the prone position, especially on the Wilson frame, the hypotension observed may be more a result of caval compression and decreased return of blood to the heart than high spinal level. Finally, it would be interesting to note whether any time was needed after preparatory time for the isobaric spinal to set up prior to initiation of surgery. Complete onset of motor and sensory block was found to be significantly longer with isobaric compared with hyperbaric bupivacaine [2]. We concur with Rung et al. that spinal anesthesia is more advantageous than general anesthesia for lumbar disk surgery. Different techniques should now be studied to determine which local anesthetic and baricity provides the best intraoperative and postoperative conditions for lumbar diskectomy. W. Scott Jellish, MD, PhD John Shea, MD Zuhair Thalji, MD Department of Anesthesiology; Loyola University Medical Center; Strich School of Medicine; Maywood, IL 60153

Isobaric Spinal Anesthesia for Lumbar Disk Surgery

Isobaric Spinal Anesthesia for Lumbar Disk Surgery

Isobaric Spinal Anesthesia for Lumbar Disk Surgery

Isobaric Spinal Anesthesia for Lumbar Disk Surgery

The Direction of the Whitacre Needle Aperture Affects the Extent and Duration of Isobaric Spinal Anesthesia

The use of Whitacre spinal needles results in directional flow out of the needle aperture, diverting local anesthetic from the longitudinal axis of the needle.Thus, a change in orientation of the needle aperture would be expected to result in a different local anesthetic distribution in the subarachnoid space. We studied 40 outpatients undergoing elective knee arthroscopy under spinal anesthesia with 60 mg plain lidocaine 2% in a prospective, double-blinded manner. Patients were randomly assigned to either Group I (needle aperture oriented in a cephalad direction throughout intrathecal injection) or Group II (aperture directed caudally). Onset and offset of sensory and motor block were analyzed at frequent intervals. Times to completion of ambulatory milestones, including discharge, were recorded. Group I was characterized by a higher sensory level (T 3.4 +/- 1.3 vs T 6.6 +/- 2.8, P < 0.001). Group I had significantly shorter duration of lumbar sensory anesthesia (149.2 +/- 30.6 min vs 177.8 +/- 23.5 min, P < 0.01) and motor blockade (117.6 +/- 26.1 min vs 150.0 +/- 22.8 min, P < 0.001). Mean time to outpatient discharge was approximately 32 min shorter in Group I. The orientation of the Whitacre needle aperture exerts a major influence on sensory level, as well as the duration of isobaric lidocaine spinal anesthesia. (Anesth Analg 1997;84:337-41)

クロニジン経口投与によるテトラカイン脊椎麻酔の延長効果

クロニジン経口投与によるテトラカイン脊椎麻酔の延長効果

Effect of Increasing Amounts of Epinephrine during Isobaric Bupivacaine Spinal Anesthesia in Elderly Patients

The effects of adding epinephrine to isobaric bupivacaine spinal anesthesia were investigated in 96 ASA class II-III patients aged 75 yr or more scheduled for lower extremity surgery. The subjects were randomly allocated into six groups. All patients received 15 mg bupivacaine plain solution in 4 ml, in the horizontal position. Patients in group 1 received bupivacaine plus 1 ml normal saline; patients in other groups received bupivacaine plus increasing dosages of epinephrine: 0.1 mg (group 2), 0.2 mg (group 3), 0.3 mg (group 4), 0.4 mg (group 5), 0.5 mg (group 6). The segmental level of sensory loss was tested using forceps. The time required for maximal spread of the sensory blockade was significantly 50% greater in group 5 than in group 1. No difference was observed, however, between mean highest levels. Addition of 0.2 mg epinephrine prolonged by a significant 25% regression time to L-2 level. Addition of 0.3 and 0.4 mg epinephrine significantly prolonged two-segment regression time by 36 and 53%, respectively, and regression to L-2 level by 29 and 44%, respectively. Addition of 0.5 mg epinephrine did not result in further prolongation of anesthesia. Motor blockade was also increased by addition of epinephrine. It is concluded that addition of 0.3 mg epinephrine may be useful to increase duration of isobaric bupivacaine spinal anesthesia.

Isobaric Tetracaine Spinal Anesthesia and the Lithotomy Position

The extent and pattern of anesthesia produced by hyperbaric and by isobaric 0.5% tetracaine spinal anesthesia were compared in this blind-observer, randomized study of 103 spinal anesthetics performed in 98 patients having genitourinary surgery in the lithotomy position. Pinprick stimulation showed no significant differences in maximum segmental sensory levels, times to maximum level, or duration of anesthesia for isobaric as compared to hyperbaric tetracaine. No parameters were significantly altered by barbotage of isobaric tetracaine solutions. With injections given to patients in the sitting position and with patients subsequently maintained in a horizontal lithotomy position before being put in the lithotomy position, the addition of dextrose to tetracaine solutions injected at room temperature into the subarachnoid space does not significantly alter the cephalad spread of spinal anesthesia.

Isobaric Spinal Anesthesia with Bupivacaine and Tetracaine

Isobaric Spinal Anesthesia with Bupivacaine and Tetracaine