Effects of levobupivacaine and bupivacaine on rat myometrium

Objective： To study the effect of levobupivacaine and bupivacaine on the contractility of isolated uterine muscle strips from pregnant and non-pregnant female rats. Methods： Full-thick myometrial strips were prepared from 18- to 2 l-day pregnant （n=8） and non-pregnant rats （n=7）. After contractions became regular, strips were exposed to cumulative concentrations of the two drugs from 10^-8 to 10^-4 mol/L, amplitude and frequency of the uterine contraction was recorded. Results： Two local anesthetics caused a concentration dependent inhibition on contractility of myometrial strips from pregnant and non-pregnant rats. In the myometrium from non-pregnant rats, -log/C50 of levobupivacaine and bupivacaine were 4.85 and 4.25 respectively. In the myometrium from pregnant rats, similar concentrations of levobupivacaine and bupivacaine were observed, -log/C50 were 2.7 and 2.9 respectively. Levobupivacaine produced an increase in amplitude of contractions, while bupivacaine showed an increased trend in frequency. Conclusion： These results demonstrate that levobupivacaine and bupivacaine may inhibit myometrium contractility. The inhibitory effect of levobupivacaine or bupivacaine is not enhanced by gestation in rat. Levobupivacaine may have more positive influence than bupivacaine in pregnant myometrium.

Anti-inflammatory efficiency of levobupivacaine in an experimental colitis model

AIM:To investigate the efficiency of levobupivacaine in treating experimentally induced colitis in rats.METHODS:Colitis was induced by trinitrobenzene sulfonic acid and ethanol in 30 rats under general anesthesia,and 10 rats were used as a sham group.Subsequent to induction of colitis,rats were divided into three groups;budesonide group received 0.1 mg/kg budesonide,levobupivacaine group received 10 mg/kg levobupivacaine and saline group received 1 mL saline solution via rectal route for 7 d.In the sham group,only routine rectal catheterization was performed without use of any material.At the end of 7 d,laparotomy and total colectomy were performed for histopathological ex-amination in all rats and blood samples were drawn for measurement of tumor necrosis factor(TNF)-αand interleukin(IL)-6 following cardiac puncture.Macroscopic and microscopic evaluations of the specimens were performed by a pathologist blinded to group assignment of the rats.RESULTS:Weight loss(P=0.016)and macroscopic examination scores(P=0.001)were significantly higher in saline group than others.Histopathological scoring was comparable between all colitis groups(P=0.350).There was no significant difference in TNF-αlevels and IL-6 levels(P=0.150).CONCLUSION:The significant improvement in macroscopic scores suggests that levobupivacaine may have topical anti-inflammatory effects in an experimental colitis model;however,this finding was not supported by microscopic findings.

Comparison of a Standard Dose with a Low Dose of Levobupivacaine in Spinal Anesthesia for Caesarean Section

Obstetric anesthesia carries great responsibilities because there are two patients, the mother and the fetus. The purpose of the present study is to compare two doses of Levobupivacaine for spinal anesthesia at elective cesarean section, to determine the best dose that can give mother and fetal hemodynamic stability and a fast anesthesia recovery after the surgery. Method: We conducted a prospective randomized comparative study in 56 patients undergoing cesarean section with spinal dose of Levobupivacaine 6 mg (22 patients) and 10 mg (34 patients), both groups combined with 25 μg of fentanyl. The two doses of local anesthetic were compared with regard to sensory and motor blockade, the need for supplementation epidural, the severity of hypotension and other complications. Result: The 6 mg of levobupivacaine group presents no difference in the incidence of hypotension, bradycardia, nauseas or vomiting compared with the 10 mg of levobupivacaine group, but presents higher incidence of supplementary analgesia and lower mother satisfaction. Conclusions: The combination of 6 mg of levobupivacaine with 25 μg of fentanyl on spinal anesthesia can be an option for short time cesarean section, buy doesn’t present a superior profile in side effects over the 10 mg of levobupivacaine with 25 μg of fentanyl combination with worst maternal satisfaction.

Comparison between 0.06% and 0.1% Levobupivacaine Combined with 2 μg/mL of Fentanyl for Epidural Labor Analgesia

Purpose: Levobupivacaine is thought to be a good alternative to bupivacaine for epidural labor analgesia because of its pharmacologic profile. However, the optimal concentration of levobupivacaine for labor analgesia has not been adequately studied. The objective of this retrospective study was to compare the analgesic effect of levobupivacaine between 0.06% and 0.1% both combined with 2 μg/mL of fentanyl. Methods: Primiparous women (ASA I, II) who delivered their babies to our hospital using combined spinal epidural analgesia and patient-controlled epidural analgesia between August 1, 2011 and September 30, 2011 were included into this retrospective study. The analgesic solution for epidural administration was 0.06% levobupivacaine with 2 μg/mL of fentanyl between August 1 and 31, and 0.1% levobupivacaine with 2 μg/mL of fentanyl between September 1 and 30. Their anesthetic and obstetric charts were reviewed to compare obstetric outcome, anesthetic intervention, and patients’ satisfaction. Results: There were 46 women fulfilling the inclusion criteria: 23 women in 0.06% group, and 23 women in 0.1% group. The number of patients who needed more than 3 requests for one actual bolus was significantly higher in the 0.06% group (P 0.05). Conclusion: Our results revealed that 0.06% levobupivacaine combined with 2 μg/mL fentanyl does not provide sufficient analgesic effects for epidural labor analgesia. It seems that levobupivacaine has not been adequately studied after its withdrawal from the US market. Further studies should be conducted to determine the optimal concentration of levobupivacaine for epidural labor analgesia.

Laparoscopic-assisted instillation of epinephrine and levobupivacaine enables cornual excision and anatomical reconstruction in unruptured cornual pregnancy

The objective of this report is to describe the possible use of intramiometrial vasoconstrictive agents for laparoscopic management of interstitial pregnancy and the consequences in anatomical results and reproductive outcomes. Cornual resection can be performed by laparoscopy, but the high vascularization of this area may result in profuse bleeding and laparoscopic suturing under these conditions might be impossible for the majority of the surgeons. We present a case that describes the possible use of intramiometrial instillation of a solution of diluted epinephrine and levobupivacaine under laparoscopic guidance that permitted a bloodless cornual excision with complete reconstruction. Vasoactive agents might have potentially serious cardiovascular side effects and the correct election of the active principle and the dosage is essential to reduce the risk of the surgery and obtain good anatomical results and reproductive outcomes. In conclusion, unruptured interstitial pregnancies can be managed successfully with intramyometrial instillation of epinephrine and bupivacaine. This simple technique is particularly attractive as it facilitates anatomical reconstruction of the cornual area, gives enough time to perform a complete suture of the defect and reduces the risk of laparotomic conversion.

Comparison between intrathecal hyperbaric bupivacaine and levobupivacaine for ambulatory knee arthroscopy

AIM: To compare the effect of hyperbaric levobupivacaine and bupivacaine on the quality of the block, patient satisfaction, and discharge time in patients undergoing arthroscopic knee surgery under unilateral spinal anesthesia.METHODS: One hundred and thirty-two patients, American Society of Anaesthesiologists Ⅰ or Ⅱ, scheduled for elective ambulatory knee arthroscopy were randomly assigned to four double-blind groups. To achieve a unilateral spinal block, Group BF received 5 mg of hyperbaric bupivacaine plus 20 μg of fentanyl intrathecally, Group LF received 5 mg of hyperbaric levobupivacaine plus 20 μg of fentanyl intrathecally, Group B received 5 mg of hyperbaric bupivacaine intrathecally, and Group L received 5 mg of hyperbaric levobupivacaine intrathecally. The level and duration of the sensory block, the intensity and duration of the motor block, the time to first analgesic requirement, and the time elapsed until the patient's discharge were recorded. Hemodynamic values and adverse effects were also recorded. RESULTS: The duration of time needed to reach the T12 dermatome level was significantly longer in Group L [7(3-20) min] than in Group B [6(3-12) min](P = 0.006). The maximum sensory level reached on the side undergoing the operation was significantly higher in Group BF than in Group B(P < 0.05). The intensity of the motor blockade was greater in Group BF than in Group LF and L. Complete recovery from motor blockade occurred earlier in Groups LF [75(45-165) min] and L [63(35-120) min] than in Group BF [115(60-180) min](P < 0.05). The length of time needed for the sensory block to regress to the level of S2 was shorter in Group L(154 ± 50) than in Group BF(192 ± 66)(P < 0.05). The quality of the block was significantly lower in Group L than in Groups BF, LF and B(P = 0.012, P = 0.003, and P < 0.001, respectively). The time elapsed until Visual Analog Scale ≥ 4 was significantly shorter in Group L(110 ± 48) than in Groups BF(200 ± 60), LF(156 ± 61) and B(162 ± 52)(P < 0.05). The time elapsed until the patient's discharge was shorter in Groups B(244 ± 54) and L(229 ± 55) than in Group BF(288 ± 64)(P = 0.021 and P = 0.001, respectively). There were no differences among the groups regarding hemodynamic parameters and adverse events, except for pruritus. The occurrence of pruritus was significantly more frequent in Groups BF and LF than in other groups. CONCLUSION: In conclusion, 5 mg of hyperbaric bupivacaine and 5 mg of hyperbaric levobupivacaine plus 20 μg of fentanyl provided a better spinal anesthesia than 5 mg of hyperbaric levobupivacaine alone.

A Comparison of Spinal Anesthesia with Levobupivacaine and Hyperbaric Bupivacaine for Cesarean Sections:A Randomized Trial

Purpose: Levobupivacaine showed a lower risk of cardiovascular and central nervous system (CNS) toxicity than bupivacaine which is the most popular local anesthetic agent in obstetric practice. The aim of this study was to investigate the clinical efficacy of levobupivacaine compared with hyperbaric bupivacaine for spinal anesthesia for cesarean section. Methods: 60 pregnant women in ASA I - II group scheduled to have elective cesarean operation were allocated into the study. Patients were randomly divided into two groups. The combinations 10 mg levobupivacaine (0.5%) + fentanyl (15 μcg) for Group LF (n = 30) patients, 10 mg hyperbaric bupivacaine (0.5%) + fentanyl (15 μcg) for BF (n = 30) patients were intrathecally administrated a total of 2.3 cc. Sensory and motor block characteristics of the groups were assessed with pinprick and Bromage scale;observed hemodynamic changes and side effects were recorded. Results: The time to reach maximum dermatome for the sensory block, time to regression by two dermatomes and time to regress to T12 dermatome was found to be significantly long in Group BF. It was observed that in Group BF, the evolution of the motor block was faster and lasted longer. Whereas hypotension, bradycardia and nausea were less in Group LF, the need for ephedrine was higher in Group BF (p < 0.05). Conclusion: Since motor block time is shorter, and side effects like hypotension, bradycardia and nausea are less, the combination of levobupivacaine + fentanyl can be a good alternative in cesarean sections.

Comparison of bupivacaine, ropivacaine and levobupivacaine with sufentanil for patient-controlled epidural analgesia during labor： a randomized clinical trial

Ropivacaine and levobupivacaine have been introduced into obstetric analgesic practice with the proposed advantages of causing less motor block and toxicity compared with bupivacaine. However, it is still controversial whether both anesthetics are associated with any clinical benefit relative to bupivacaine for labor analgesia. This study aimed to compare the analgesic efficacy, motor block and side effects of bupivacaine, ropivacaine and levobupivacaine at lower concentrations for patient-controlled epidural labor analgesia. Methods Four hundred and fifty nulliparous parturients were enrolled in this randomized clinical trial. A concentration of 0.05%, 0.075%, 0.1%, 0.125% or 0.15% of either bupivacaine （Group B）, ropivacaine （Group R） or levobupivacaine （Group L） with sufentanil 0.5 ug/ml was epidurally administered by patient-controlled analgesia mode. Effective analgesia was defined as a visual analogue scale score was 〈30 mm. The relative median potency for each local anesthetic was calculated using a probit regression model. Parturients demographics, sensory and motor blockade, obstetric data, maternal side effects, hourly volumes of local anesthetic used, and others were also noted. Results There were no significant differences among groups in the numbers of effective analgesia, pain scores, hourly local anesthetic amount used, sensory and motor blockade, labor duration and mode of delivery, side effects and maternal satisfaction （P 〉0.05）. The relative median potency was bupivacaine/ropivacaine： 0.828 （0.602-1.091）, bupivacaine/levobupivacaine： 0.845 （0.617-1.12）, ropivacaine/levobupivacaine： 1.021 （0.774-1.354）, respectively. However, a significantly less number of effective analgesia and higher hourly local anesthetic use were observed in the concentration of 0.05% than those of 〉0.1% within each group （P 〈0.05）. Conclusions Using patient-controlled epidural analgesia, lower concentrations of bupivacaine, ropivacaine and levobupivacaine with s＇ufentanil produce similar analgesia and motor block and safety for labor analgesia. The analgesic efficacy mainly depends on the concentration rather than the type of anesthetics.