Quantitative assessment of motor block in labouring women receiving epidural analgesia

Comparison of analgesic effects between programmed intermittent epidural boluses and continuous epidural infusion after cesarean section: a randomized controlled study

BACKGROUND

This study aimed to compare the analgesic effects of programmed intermittent epidural boluses (PIEB) and continuous epidural infusion (CEI) for postoperative analgesia after elective cesarean section (CS).

METHODS

Seventy-four women who underwent elective CS were randomized to receive either PIEB or CEI. The PIEB group received 4 ml-intermittent boluses of 0.11% ropivacaine every hour at a rate of 120 ml/h. The CEI group received a constant rate of 4 ml/h of 0.11% ropivacaine. The primary outcome was the pain score at rest at 36 h after CS. Secondary outcomes included the pain scores during mobilization, time-weighted pain scores, the incidence of motor blockade, and complications-related epidural analgesia during 36 h after CS.

RESULTS

The pain score at rest at 36 h after CS was significantly lower in the PIEB group compared with that in the CEI group (3.0 vs. 0.0; median difference: 2, 95% CI [1, 2], P < 0.001). The mean time-weighted pain scores at rest and during mobilizations were also significantly lower in the PIEB group than in the CEI group (pain at rest; mean difference [MD]: 37.5, 95% CI [24.6, 50.4], P < 0.001/pain during mobilization; MD: 56.6, 95% CI [39.8, 73.5], P < 0.001). The incidence of motor blockade was significantly reduced in the PIEB group compared with that in the CEI group (P < 0.001).

CONCLUSIONS

PIEB provides superior analgesia with less motor blockade than CEI in postpartum women after CS, without any apparent adverse events.

Effects of midline laparotomy on cough strength: a prospective study measuring cough pressure

BACKGROUND

Laparotomy is assumed to decrease cough strength due to three factors: abdominal muscle trauma, postoperative pain, and diaphragmatic dysfunction. However, the effect of trauma from laparotomy itself on strength (net of the other two factors) has not been measured to our knowledge. The aim of this study was to measure the effect of laparotomy on cough strength after first measuring the effect of epidural analgesia.

METHODS

In 11 patients scheduled for open midline laparotomy, cough pressure (PCOUGH), a proxy for strength, was measured with a rectal balloon at three moments: before the procedure, at baseline; before surgery, under epidural bupivacaine to T6; and postoperatively, under epidural bupivacaine to the same analgesic level (T6). Continuous variables were compared using the Wilcoxon signed-rank test. The repeatability of PCOUGH measurements was confirmed with the intraclass correlation coefficient (ICC). Pain on coughing, hand grip strength, and the Ramsay and modified Bromage scores were also recorded.

RESULTS

Median (interquartile range) PCOUGH decreased from a baseline of 103 (89-137) to 71 (56-116) cmH2O under presurgical epidural bupivacaine (P=0.003). Postoperative PCOUGH remained unchanged at 76 (46-85) cmH2O under epidural analgesia (P=0.131). The ICCs indicated excellent repeatability of the PCOUGH measurements (P<0.001). Pain on coughing was 0 to 1 in all subjects. Hand grip strength and the Ramsay and Bromage scores were unchanged.

CONCLUSIONS

Although thoracic epidural bupivacaine reduces cough strength as measured by PCOUGH, midline laparotomy does not further reduce strength in the presence of adequate epidural analgesia.

The Effect of Caudal Ropivacaine and Morphine on Postoperative Analgesia in Total Laparoscopic Hysterectomy: A Prospective, Double-Blind, Randomized Controlled Trial

Purpose

Multiple regional nerve blocks proved no additional benefit in total laparoscopic hysterectomy in multimodal analgesia, as postoperative pain may mainly originate from the vaginal cuff. Theoretically, caudal block can relieve pain from the vaginal cuff by a sacral spinal nerve block. We aimed to verify whether a caudal block with ropivacaine and morphine can achieve an analgesic effect without additional adverse effects after a total laparoscopic hysterectomy.

Patients and Methods

Forty-eight patients undergoing total laparoscopic hysterectomy were randomly allocated to receive preoperative caudal block with 20 mL of mixture including 0.25% ropivacaine and 2 mg morphine (caudal block group) or sham block (sham group). The primary outcome was the postoperative 24 h cumulative sufentanil consumption.

Results

Median (IQR) sufentanil consumption in the first 24 postoperative hours of the caudal block group and the sham group was 0.00 (0.00 to 0.05) μg/kg vs 0.13 (0.04 to 0.21) μg/kg, respectively, p < 0.001. The majority of patients felt that visceral pain was more intense than incisional pain at 1, 6, 12, and 24 h post-surgery in the sham group (95.8% at 1 h, 95.8% at 6 h, 95.8% at 12 h, and 75% at 24 h post-surgery). Compared to the sham group, the caudal block reduced visceral pain scores at rest and during movement at 1 h (p < 0.001), 6 h (p < 0.001), 12 h (p < 0.001), and 24 h (p < 0.001) post-surgery. Intraoperative remifentanil consumption was significantly lower in the caudal block group than in the sham group (p = 0.004). There were no significant differences in other secondary outcomes between the two groups.

Conclusion

A caudal block with ropivacaine and morphine could provide a satisfactory analgesic effect for 24 h postoperatively without additional adverse effects after total laparoscopic hysterectomy.

Perioperative Anxiolysis and Analgesic Effect after Premedication with Melatonin and Pregabalin in Total Hip Arthroplasty under Spinal Anaesthesia: A Prospective Comparative Trial

Background

Preoperative anxiety plays a critical role in post-operative pain response and other outcomes. Melatonin is a naturally secreted hormone which has anxiolytic, sedative, and analgesic properties. Pregabalin, analogue of gabapentin which has property of anxiolytic and analgesic effects.

Materials and Methods

Total 96 patients undergoing total hip arthroplasty, divided into 3 groups of 32 each and were given placebo (group I), melatonin 6 mg (group II), and pregabalin 150 mg (group III). Anxiety level, postoperative pain score, sedation level and duration as well as characteristics of spinal anaesthesia were assessed with other vital parameters.

Results

Group I showed an increment in the anxiety score from baseline whereas in group II and group III, there was a decline in pre-operative anxiety score from baseline at all the periods of observation and more significantly in group III. Visual analogue scale (VAS) score and total dose of rescue analgesia were highest in group I, but group II and group III were comparable to each other. However, the durations of spinal anaesthesia and motor blockade showed a statistically significant difference with maximum duration in group III followed by II and then I. The level of sedation among the three groups were comparable at all the periods of observation.

Conclusions

Pregabalin was found better for perioperative anxiolysis, post-operative analgesia and for prolongation of duration of spinal anaesthesia when compared to melatonin.

Comparison of the effects of spinal anesthesia, paracervical block and general anesthesia on pain, nausea and vomiting, and analgesic requirements in diagnostic hysteroscopy: A non-randomized clinical trial

Background

The aim of this study was to compare the effect of spinal anesthesia (SPA), paracervical block (PB), and general anesthesia (GA), on pain, the frequency of nausea and vomiting and analgesic requirements in diagnostic hysteroscopy.

Methods

This single-center, non-randomized, parallel-group, clinical trial was conducted on 66 diagnostic hysteroscopy candidates who were selected by convenience sampling at Fatemieh Hospital, in Hamadan, Iran, in 2021.

Results

The mean pain score during recovery and the need for analgesic injections was found to be significantly higher in the GA group compared to that in the SPA group (pain: 3.77 ± 2.25 vs. 0.10 ± 0.30, P < 0.001), (analgesic: 50 vs. 0%, P < 0.001) and PB group (pain: 3.77 ± 2.25 vs. 0.90 ± 1.37, P < 0.001), (analgesic 50 vs. 10%, P < 0.001), respectively. However, no statistically significant difference was observed between the mean pain score between SPA and PB groups (0.10 ± 0.30 vs. 0.90 ± 1.3, P = 0.661). In addition, there were no significant differences between groups on nausea/vomiting after operation (P = 0.382). In adjusted regression analysis (adjusting for age, weight, gravid, abortion, and cause of hysteroscopy), the odds ratio (OR) of pain score during recovery was increased in PB (OR: 4.471, 95% CI: 1.527-6.156, P = 0.018) and GA (OR: 8.406, 95% CI: 2.421-9.195, P = 0.001) groups compared with the SPA group. However, in adjusting based on times of surgery duration, anesthesia duration, recovery and return of motor function, the ORs of pain score between groups was not statistically significant.

Conclusion

Despite reduced pain during recovery in patients receiving SPA, duration of anesthesia, recovery period, and return of motor function were significantly prolonged compared to those receiving PB or GA. It seems that PB with less recovery time and faster return of motor function than SPA and also mild pain during recovery compared to GA can be a good option for hysteroscopy.

Clinical trial registration

http://www.irct.ir, identifier IRCT20120915010841N26.

Comparison between 10 and 12 mg doses of intrathecal hyperbaric (0.5%) bupivacaine on sensory block level after first spinal failure in cesarean section: A double-blind, randomized clinical trial

Background

Reducing adverse effects during cesarean delivery and improving the quality of sensory blocks with appropriate doses of intrathecal hyperbaric bupivacaine can play an important role in the safe management of cesarean delivery. The aim of this study was to compare the doses of 10 and 12 mg of intrathecal hyperbaric bupivacaine 0.5% on sensory block level after first spinal failure in cesarean section (CS).

Methods

In this double-blind, randomized clinical trial, 40 candidates of CS after first spinal failure with class I-II based on American Society of Anesthesiologists (ASA) were randomly assigned into two equal groups (n = 20). Group A and B received the spinal anesthesia with 10 mg and 12 mg of hyperbaric bupivacaine (0.5%), respectively. Maximum levels of sensory block, motor block quality, and vital signs were measured in two groups by 60 min after SPA. Incidence of SPA complications during surgery were also recorded. Data were analyzed by SPSS ver.21 software using repeated measures analysis of variance at 95% confidence interval (CI) level.

Results

Excellent quality of sensory blocks and complete quality of motor blocks were achieved in all participants (100%). However, the mean time to onset of anesthesia (4.47 ± 0.69 vs. 3.38 ± 0.47, P < 0.001) and time to reach T10 level (60.73 ± 11.92 vs. 79.00 ± 19.21, P < 0.001) in the Group A, were significantly shorter than in the patients of Group B. The incidence of hypotension (P = 0.001), nausea/vomiting (P = 0.007) and bradycardia (P = 0.012) as well as administration of ephedrine and atropine were significantly higher in Group B compared to Group A.

Conclusion

Spinal anesthesia can be safely repeated with a 10 mg of hyperbaric bupivacaine 0.5% in a caesarean section after the initial spinal failure.

Clinical trial registration

[https://en.irct.ir/trial/40714], identifier [IRCT20120915010841N20].

Evaluation Effect of Aspiration of 0.2 ml of Cerebrospinal Fluid After Completion of Injection 0.5% Bupivacaine and Reinjection Into Subarachnoid Space on Sensory and Motor Block in Cesarean Section: A Randomized Clinical Trial

Background

Spinal anesthesia (SPA) is the most common type of anesthesia administered for cesarean section. The main aim of this study was to evaluate the effect of aspiration of CSF (0.2 mL) immediately after SPA with hyperbaric 0.5% bupivacaine on the extent of sensory and motor block.

Methods

In this clinical trial, 60 women at ≥37 weeks of gestation and aged between 18 and 46 years, candidate for cesarean delivery under spinal anesthesia were randomly allocated into two equal groups (n = 30). Group A (CSF-aspiration group) received the spinal anesthesia with 10 mg of hyperbaric 0.5% bupivacaine with aspiration of 0.2 ml of CSF. Group B (no-CSF-aspiration group) received only 10 mg of 0.5% hyperbaric bupivacaine. Pin-prick analgesia and motor block were tested during the induction.

Results

The mean maximum level of analgesia was T6 in each group. Although the mean time to reach the maximum level of anesthesia (4.43 ± 5.14 vs. 2.76 ± 2.04, P = 0.107) and to reach T10 level (50.56 ± 11.51 vs. 49.10 ± 13.68, P = 0.665) in the CSF-aspiration group is longer than the non-CSF-aspiration group, but this differences were not significant. There were no significant between-group differences regarding sensory and motor block quality (P = 0.389) or failed SPA (four cases in CSF-aspiration group vs. two cases in no-CSF-aspiration group, P = 0.389). The incidence of bradycardia, hypotension, headache, vomiting and nausea were similar in both groups (P > 0.05). In addition, the difference in hemodynamic parameters between the two groups over times was not statistically significant.

Conclusion

Our finding indicated that the aspiration of 0.2 ml of CSF after injection of spinal anesthesia with hyperbaric 0.5% bupivacaine does not seem to affect the extent of sensory and motor block, success rate, or outcome after SPA in cesarean section.

Clinical Trial Registration

[https://www.irct.ir/search/result?query=IRCT20120915010841N25], identifier [IRCT20120915010841N25].

A Randomized Controlled Trial for Prevention of Postspinal Anesthesia Shivering in Gynecological Surgeries: Mirtazapine vs. Dexamethasone

Background

The frequency of shivering regarding regional anesthesia is 55%. Newer effective and tolerable options for postspinal anesthesia shivering (PSAS) prophylaxis are necessary to improve patients' quality of care. This research assessed the impact of preemptive mirtazapine versus preemptive dexamethasone to decrease frequency and severity of PSAS in gynecological procedures.

Methods

300 patients booked for gynecological procedures under spinal anesthesia (SA) were randomly apportioned into three groups (100 each) to get one preemptive dose of 30 mg mirtazapine tablet (M group), 8 mg dexamethasone diluted in 100 ml of saline infusion (D group) or placebo (C group) two hours before surgery. Incidence of clinically significant PSAS was the primary outcome. Core temperature, shivering score, hemodynamics changes, adverse events, and patient satisfaction score were documented as secondary outcomes.

Results

Compared with C group, mirtazapine and dexamethasone decreased incidence of clinically significant shivering (74% vs. 16% and 31%, respectively; P < 0.001). M and D groups had less hypotensive episodes during 5–25 min after intrathecal injection (P < 0.001). 90 min after SA, tympanic temperatures were lower than baseline values in the three groups (P < 0.001). Pruritus, nausea, and vomiting were more often in C group (P < 0.001), whereas sedation was more frequent in M group (P < 0.001). C group had the lowest satisfaction scores (P < 0.001).

Conclusion

Prophylactic administration of mirtazapine or dexamethasone attenuated shivering with minimal hazards in patients scheduled for gynecological surgeries under spinal anesthesia with priority to mirtazapine. The trial is registered with NCT03675555.

Comparison of spinal anaesthesia with isobaric chloroprocaine and general anaesthesia for short duration ambulatory urological procedures

Background and Aims:

Chloroprocaine is a short-acting local anaesthetic agent for spinal anaesthesia (SA) that has been used in day care surgeries due to its faster recovery characteristics and faster discharge rates compared to other local anaesthetics. This study aimed at finding out its efficacy for the same as compared to general anaesthesia (GA).

Material and Methods:

This observational study was conducted on 60 patients belonging to the American Society of Anaesthesiologists (ASA) physical status I and II who underwent short elective urological procedures (<60 min) under GA (group GA) as per standard of care in our hospital (n = 30) and SA (group SA) with 50 mg 1% isobaric 2-Chloroprocaine (n = 30). Time taken to meet the discharge criteria, modified Aldrete score and modified post anaesthesia discharge score in each group were noted. The cost of the anaesthetic procedure, anaesthetic procedural time, hemodynamics, supplemental analgesia, complications related to the procedure were noted and compared.

Results:

Patient characteristics and duration of surgery were comparable. Time taken by group SA was significantly higher than group GA to meet the discharge criteria. Cost of GA [2624.76 (166.16) units] was significantly more than SA [1561.63 (81.32) units, P < 0.05]. There was no requirement of supplemental analgesia in group SA and no hemodynamic instability or complications in either group.

Conclusion:

GA is significantly better as compared to SA with 50 mg 1% isobaric 2-Chloroprocaine as an anesthetic technique in day care urology surgeries in terms of faster recovery and faster discharge rate but is costlier.

Postspinal anesthesia shivering in lower abdominal and lower limb surgeries: a randomized controlled comparison between paracetamol and dexamethasone

Background

Shivering is known to be a frequent complication in patients undergoing surgery under neuraxial anesthesia with incidence of 40–70%. Although many pharmacological agents have been used to treat or prevent postspinal anesthesia shivering (PSAS), the ideal treatment wasn’t found. This study evaluated the efficacy of paracetamol and dexamethasone to prevent PSAS in patients undergoing lower abdominal and lower limb surgeries.

Methods

Three hundred patients scheduled for surgeries under spinal anesthesia (SA) were allocated into three equal groups to receive a single preoperative dose of oral paracetamol 1 g (P group), dexamethasone 8 mg intravenous infusion (IVI) in 100 ml normal saline (D group) or placebo (C group), 2 h preoperatively, in a randomized, double-blind trial. The primary endpoint was the incidence of clinically significant PSAS. Secondary endpoints included shivering score, the change in hemodynamics, adverse events (e.g., nausea, vomiting and pruritis) and patients` satisfaction.

Results

Clinically significant PSAS was recorded as (15%) in P group, (40%) in D group and (77%) in C group (P < 0.001). The mean blood pressure values obtained over a 5-25 min observation period were significantly higher in the D group (P < 0.001). Core temperature 90 min after SA was significantly lower in the 3 groups compared to prespinal values (P < 0.001). Nausea, vomiting and pruritis were significantly higher in the C group (P < 0.001). P and D groups were superior to C group regarding the patients’ satisfaction score (P < 0.001).

Conclusion

Paracetamol and dexamethasone were effective in prevention of PSAS in patients undergoing lower abdominal and lower limb surgeries compared to placebo controls.

Trial registration

ClinicalTrials.gov Identifier: NCT03679065 / Registered 20 September 2018 - Retrospectively registered, http://www.ClinicalTrial.gov.

Comparison of standing stability with different doses in epidural fentanyl among post-cesarean delivery women: a prospective trial

BACKGROUND

The study purpose was to determine the safety and efficacy of different doses of epidural fentanyl plus local anesthetics on ambulation for patients who had elective cesarean delivery.

METHODS

A prospective study at a single community hospital used posturography to compute Sway area for assessment of standing stability [ISRCTN14517337]. Continuous epidural infusion of 0.2% ropivacaine containing either 2.5 mcg.mL^-1 (Group 1, n = 8) or 5 mcg.mL^-1 fentanyl (Group 2, n = 8) was randomly assigned to an individual and started at a rate of 5 mL.h^-1 postoperatively and continued for 48 hours after cesarean delivery in addition to standing acetaminophen and ibuprofen. Posturography measured with SYMPACK™ was used to compute Sway area for investigation of standing stability. The unpaired t-test was used to compare continuous variables between groups. Analysis of variance (ANOVA) was used to assess differences of Sway area measured repeatedly within groups.

RESULTS

Participants' demographics, pain status, and leg motor function one day after cesarean delivery were not different between groups. Sway area in Group 1 was not different across three repeated measurements. Sway area of Group 2 on postoperative day 1, with epidural analgesia, was significantly higher than at the baseline (4.1 ± 2.8 vs. 3.1 ± 1.1 cm², p < 0.05).

CONCLUSIONS

Because both low and high concentrations of epidural fentanyl allowed participants to ambulate with the same pain effect, the lower concentration of continuous epidural fentanyl (2.5 mcg.mL^-1 at 5 mL.h^-1) is warranted to avoid potential adverse events during ambulation after cesarean delivery.

Duration of postoperative analgesia with Nalbuphine vs Butorphanol as an adjunct to spinal anesthesia for lower limb orthopedic surgeries: A randomized double-blind active control trial

Background and Aims:

Nalbuphine as well as butorphanol as adjuvant to intrathecal bupivacaine have been studied in comparison to bupivacaine alone. Both are kappa receptor agonist and have never been compared for its efficacy in terms of postoperative analgesia. The aim of this study was to evaluate duration of postoperative analgesia as well as intraoperative block characteristics using intrathecal nalbuphine hydrochloride (800 μg) or butorphanol (25 μg) as adjuvant to hyperbaric bupivacaine (12.5 mg) in lower limb fracture femur surgeries as compared to active control, that is, saline and bupivacaine.

Material and Methods:

This prospective, randomized, double-blind, active control study was conducted on 90 adult patients of either sex belonging to ASA grade I/II, aged 18–70 years, being operated for fracture femur surgeries in tertiary care hospital of North India. Patients were randomly divided into 3 groups (n = 30) Group A: received 0.5% hyperbaric bupivacaine 12.5 mg with 800 μg nalbuphine. Group B: Received 0.5% hyperbaric bupivacaine 12.5 mg with 25 μg butorphanol. Group C: Received 0.5% hyperbaric bupivacaine 12.5 mg with normal saline. Total volume injected was 3.0 ml. Duration of analgesia, mean VAS scores, requirement of rescue analgesia in 24 h along with intraoperative sensory or motor characteristics of block and hemodynamic parameters were studied. Statistical analysis was done using ANOVA with post-hoc Tukey test, Student’s t-test and Chi-Square test.

Results:

Demographic profile was comparable among all the three groups. Mean duration of postoperative analgesia was 348.33 ± 66.96, 156.17 ± 43.9 and 110.36 ± 29.18 min in group A, B, and C, respectively (P = 0.006). Total doses of rescue analgesia were least in group A (32), followed by group B (42) and group C (64), respectively (P = 0.001). Group A had significantly earlier onset of sensory action (P = 0.03) as compared to group B and C. There was significant difference in sensory (P = 0.08) and motor duration (P = 0.04) among all the three groups. However, onset of motor block, haemodynamic profile and side effects were comparable among groups A, B, and C (P > 0.05).

Conclusion:

Addition of 800 μg nalbuphine and 25 μg butorphanol as adjuvant to intrathecal bupivacaine has better outcome as compared to active placebo group. But intrathecal nalbuphine was more effective compared to intrathecal butorphanol in terms of prolonging postoperative analgesia, reducing rescue analgesic doses and onset of sensory block. However, hemodynamic profile and side effects were comparable among all groups.

In relation to NO-System, Stable Pentadecapeptide BPC 157 Counteracts Lidocaine-Induced Adverse Effects in Rats and Depolarisation In Vitro

Recently, the pentadecapeptide BPC 157-induced counteraction of bupivacaine cardiotoxicity has been reported. Medication includes (i) lidocaine-induced local anesthesia via intraplantar application and axillary and spinal (L4-L5) intrathecal block, (ii) lidocaine-induced arrhythmias, (iii) convulsions, and (iv) lidocaine-induced HEK293 cell depolarisation. BPC 157 applications (intraplantar, intraperitoneal, and intragastric) were given (i) immediately after lidocaine, (ii) 10 min after, or (iii) 5 min before. The BPC 157/NO-system relationship was verified with NO-agents, the NOS-blocker L-NAME and the NOS-substrate L-arginine, given alone and/or together, in axillary and spinal intrathecal blocks. BPC 157 applied immediately after lidocaine or 5 min before the application of lidocaine considerably ameliorated plantar presentation. BPC 157 medication considerably counteracted lidocaine-induced limb function failure; L-NAME was counteracted; L-arginine exhibited counteraction when given immediately after lidocaine, but prolongation was seen when given later. Given together, prophylactically or therapeutically, L-NAME and L-arginine (L-NAME + L-arginine) counteracted the other's response. BPC 157 maintained its original response when given together with L-NAME or L-arginine. When BPC 157 was given together with L-NAME and L-arginine, its original response reappeared. BPC 157 antagonised the lidocaine-induced bradycardia and eliminated tonic-clonic convulsions. Also, BPC 157 counteracted the lidocaine-induced depolarisation of HEK293 cells. Thus, BPC 157 has antidote activity in its own right against lidocaine and local anesthetics.

Comparison of bupivacaine alone and in a combination with lidocaine for caudal block in patients undergoing circumcision: A historical cohort study

OBJECTIVE

Optimal analgesia following ambulatory surgery is an important matter in patient satisfaction, and it reduces unnecessary hospital admissions. This study investigated whether a caudal block with bupivacaine alone or in a combination with lidocaine can alter postoperative pain scores, complications, and peroperative and postoperative analgesic consumption.

MATERIAL AND METHODS

This is a retrospective study that included children who underwent elective circumcision surgery under general anesthesia and caudal analgesia between January and June 2018. Among the 103 children, 17 cases were not analyzed due to an unsuccessful caudal block and procedures simultaneously underwent another operation unrelated to circumcision. We divided the study participants into two groups according to the type of local anesthetic applied: 0.5 mL/kg 0.25% bupivacaine (Group B) and 0.5 mL/kg 0.25% bupivacaine + 3 mg/kg 1% lidocaine (Group BL) caudally.

RESULTS

Pain scores were similar between these groups and remained in the mild-to-moderate range throughout the hospitalization (p>0.05). There were significant differences regarding the rescue analgesic use, first micturition, and mobilization times (p<0.001). In addition, we applied the multivariable logistic regression for fentanyl consumption adjusted for first mobilization and micturition time, unlike mobilization, a significantly increased risk for postoperative delayed micturition (OR, 1.06; 95% CI, 1.0-1.12; p=0.038) was found with intra-operative intravenous fentanyl use.

CONCLUSION

Our results suggest that the caudal block with a lidocaine+bupivacaine combination decreases rescue analgesic consumption at day-case surgery. In circumcision procedures, the caudal block is an effective and safe analgesic method for intraoperative and postoperative pain control with no side effects. This trial was registered at Clinicaltrals.gov, NCT03911648.

Optimum interval time of programmed intermittent epidural bolus of ropivacaine 0.08% with sufentanyl 0.3 μg/mL for labor analgesia: a biased-coin up-and-down sequential allocation trial

BACKGROUND

The programmed intermittent epidural bolus (PIEB) technique is widely used in labor analgesia, but the parameter settings of PIEB have not yet been standardized. We designed a study to identify the optimal interval duration for PIEB using 10 mL of ropivacaine 0.08% and sufentanyl 0.3 μg/mL, a regimen commonly used to control labor pain in China, to provide effective analgesia in 90% of women during the first stage of labor without breakthrough pain.

METHODS

We conducted a double-blind sequential allocation trial to obtain the effective interval 90% (EI90%) during the first stage of labor between April 2019 and May 2019. This study included the American Society of Anesthesiologists physical status II-III nulliparous parturients at term, who requested epidural analgesia. The bolus volume was fixed at 10 mL of ropivacaine 0.08% with sufentanyl 0.3 μg/mL. Participants were divided into four groups (groups 60, 50, 40, and 30) according to the PIEB intervals (60, 50, 40, and 30 min, respectively). The interval duration of the first parturient was set at 60 min and that of subsequent parturients varied according to a biased-coin design. The truncated Dixon and Mood method and the isotonic regression analysis method were used to estimate the EI90% and its 95% confidence intervals (CIs).

RESULTS

Forty-four women were enrolled in this study. The estimated optimal interval was 44.1 min (95% CI 41.7-46.5 min) and 39.5 min (95% CI 32.5-50.0 min), using the truncated Dixon and Mood method and isotonic regression analysis, respectively. The maximum sensory block level above T6 was in nearly 20% of parturients in group 30; however, 5.3%, 0%, and 0% of the parturients presented with sensory block level above T6 in groups 40, 50, and 60, respectively. There were no cases of hypotension and only one parturient complained of motor block.

CONCLUSION

With a fixed 10 mL dose of ropivacaine 0.08% with sufentanyl 0.3 μg/mL, the optimal PIEB interval is about 42 min. Further studies are warranted to define the efficacy of this regimen throughout all stages of labor.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1900022199; http://www.chictr.org.cn/com/25/historyversionpuben.aspx?regno=ChiCTR1900022199.

Randomised Control Trial Comparing Plain Levobupivacaine and Ropivacaine with Hyperbaric Bupivacaine in Caesarean Deliveries

Objective

The study compared spinal block characteristics of equipotent doses of plain 0.5% levobupivacaine, plain 0.75% ropivacaine and hyperbaric 0.5% bupivacaine for elective caesarean (CS) delivery.

Methods

A total of 100 parturient women undergoing elective CS under spinal anaesthesia were enrolled for the study. The parturients were randomly assigned to receive one of the following in a subarachnoid block: hyperbaric 0.5% bupivacaine 10 mg (group B), plain 0.5% levobupivacaine 10 mg (group L), or plain 0.5% ropivacaine 15 mg (group R).

Results

Motor block duration [groups B, LB, R: 143.78 (30.43) minutes, 139.31 (33.38) minutes, 137.32 (27.39) minutes, respectively; P=0.80], sensory block duration [groups B, LB, R: 122.87 (34.93) minutes, 113.03 (39.24) minutes, 125.58 (24.93) minutes, respectively; p=0.30] and first analgesic request time [groups B, LB, R: 136.87 (28.70) minutes, 133.59 (27.30) minutes, 144.19 (32.09) minutes, respectively; p=0.35] were statistically comparable. The groups were statistically comparable for sensory block onset time [T6 block; groups B, LB, R: 4.62 (2.80) minutes, 4.93 (2.63) minutes, 5.73 (3.00) minutes, respectively; p=0.29] but motor block onset time was statistically prolonged for group R as compared to group B [Bromage 3 block; group B, LB, R: 5.93 (3.41) minutes, 9.00 (4.00) minutes, 10.16 (5.66) minutes, respectively; p=0.001]. No statistically significant differences were seen in sensory and motor block recovery times, haemodynamic parameters or side-effects.

Conclusion

The anaesthesia from a spinal block with 10 mg plain levobupivacaine or 15 mg plain ropivacaine is comparable to the anaesthetic effect of 10 mg hyperbaric bupivacaine in elective caesarean deliveries.

The Effect Of The Use Of Pre-Emptive Oral Pregabalin On The Postoperative Spinal Analgesia In Patients Presented For Orthopedic Surgeries: Randomized Controlled Trial

Background

Preoperative oral pregabalin could improve postoperative analgesia and prevent chronic pain development. The aim of this study is to evaluate the effect of oral pregabalin on the duration and quality of postoperative analgesia in spinal anesthesia.

Methods

Sixty adult patients presented for internal fixation of femoral fracture under spinal anesthesia were included in the study. They were randomly distributed to a placebo group and a pregabalin group receiving 150 mg pregabalin capsules 1 hr before surgery. The onset, duration, and regression of sensory and motor block were recorded. Rescue analgesia consumption, postoperative pain score, and quality of sleep were also assessed.

Results

Oral pregabalin significantly prolonged the time to two-segment regression of sensory block, reaching 86.67±17.88 mins, the time required to regression of spinal block to L2, reaching 155.33± 34.71 mins, and the duration of motor block, reaching 138 ± 23.5 mins, with no effect on the onset of sensory or motor block (P = 0.60 and 0.62). It significantly decreased the VAS score 4 hrs, 6 hrs, and 12 hrs postoperatively, prolonged the duration of postoperative analgesia, reaching 392.00±47.23 mins, and decreased morphine consumption to 7.67±3.65 mg. It also improved the quality of sleep in the first night after surgery.

Conclusion

Preemptive oral pregabalin prolonged the time to the first request for postoperative analgesics and improved sleep in the first night after surgery.

Programmed intermittent epidural bolus as compared to continuous epidural infusion for the maintenance of labor analgesia: a prospective randomized single-blinded controlled trial

Background

Programmed intermittent epidural bolus (PIEB) techniques are a new area of interest for maintaining labor analgesia due to the potential to decrease motor block and improve labor analgesia. This study compares continuous epidural infusion (CEI) to 2 PIEB regimens for labor analgesia.

Methods

One hundred fifty patients undergoing scheduled induction of labor at term gestation having epidural labor analgesia were randomized to receive an epidural analgesia regimen of bupivacaine 0.125% with fentanyl 2 μg/ml at either PIEB 5 ml every 30 min (Group 5q30), PIEB 10 ml every 60 min (Group 10q60), or 10 ml/h continuous infusion (Group continuous epidural infusion [CEI]). The primary outcome is the pain scores throughout labor. Secondary outcomes include degree of motor block, dermatomal sensory levels, the number of physician-administered boluses, and patient satisfaction.

Results

While the average pain scores throughout labor did not differ significantly between groups, fewer patients in group 10q60 received physician-administered boluses for breakthrough pain (34.9% in 10q60 vs. 61.0% in 5q30 and 61.9% in CEI, P = 0.022). Dermatomal sensory levels, degree of motor block, and patient satisfaction did not differ significantly between groups.

Conclusions

Our study suggests that high volume PIEB regimens for labor analgesia decrease breakthrough pain and physician-administered boluses.

Sequential intrathecal injection of fentanyl and hyperbaric bupivacaine at different rates: does it make a difference? A randomized controlled trial

Background

Previous studies have shown that sequential intrathecal injection of fentanyl and hyperbaric bupivacaine for cesarean section (CS) anesthesia provides a superior anesthetic effect than use of bupivacaine alone, and prolongs postoperative analgesia. Herein, we investigated whether rapid intrathecal injection of fentanyl followed by slow injection of hyperbaric bupivacaine affects the duration of postoperative analgesia, the effectiveness of anesthesia, and hemodynamic status.

Methods

Fifty-six parturients with American Society of Anesthesiologists physical status I or II, aged 18–40 years, and scheduled to undergo elective CS were randomly assigned to 2 groups of 28 patients each. The normal sequential group received sequential intrathecal injections of fentanyl and hyperbaric bupivacaine at the same rate, each with a 5 ml syringe. The rapid sequential group received a rapid intrathecal injection of fentanyl with an insulin syringe, followed by a slow injection of hyperbaric bupivacaine with a 5 ml syringe. The onset of sensory block, the timing of the first rescue analgesia, the doses of rescue analgesics, the degree of postoperative pain, the onset and duration of motor block, the incidence and duration of hypotension, and spinal anesthesia-related complications were recorded.

Results

While both approaches had comparable spinal anesthesia-related complications, incidence and duration of hypotension, and doses of ephedrine, the rapid sequential group exhibited a more rapid onset of sensory block, a higher sensory level, and more prolonged postoperative analgesia.

Conclusions

Rapid sequential injection of fentanyl and hyperbaric bupivacaine produced superior anesthesia and more prolonged postoperative analgesia than sequential injections of both at the same rate.

Effect of intrathecal dexmedetomidine on preventing shivering in cesarean section after spinal anesthesia: a meta-analysis and trial sequential analysis

Objective

Intrathecal dexmedetomidine (DEX) has been used to prevent shivering in patients undergoing cesarean section. The aim of this meta-analysis was to evaluate whether intrathecal DEX could prevent shivering in cesarean section after spinal anesthesia.

Methods

We searched PubMed, Embase, Web of Science, and the Cochrane Library for randomized controlled trials (RCTs) comparing intrathecal DEX in cesarean section after spinal anesthesia with placebo and reporting on shivering, postoperative nausea and vomiting (PONV), hypotension, and bradycardia. Trial sequential analysis (TSA) was also carried out for RCTs comparing DEX with placebo. This meta-analysis has been registered on PROSPERO, and the registration number is CRD42017071640.

Results

Six randomized clinical trials comparing 360 patients were included in this study. Compared with placebo, intrathecal DEX significantly reduced the incidence of shivering (risk ratio [RR]=0.40; 95% CI [0.26, 0.62]; P<0.0001). No significant difference was found in the incidence of PONV (RR=1.34; 95% CI [0.82, 2.18]; P=0.24), hypotension (RR=1.09; 95% CI [0.84, 1.42]; P=0.50), or bradycardia (RR=1.55; 95% CI [0.54, 4.42]; P=0.42). However, no firm conclusions can be made based on the results of all outcomes according to the TSA.

Conclusion

This meta-analysis found that intrathecal DEX could prevent shivering in cesarean section after spinal anesthesia and did not induce PONV, hypotension, or bradycardia. However, firm conclusions cannot be made until more studies are conducted.

Comparison of saddle, lumbar epidural and caudal blocks on anal sphincter tone: A prospective, randomized study

Objective

To compare the effects of saddle, lumbar epidural and caudal blocks on anal sphincter tone using anorectal manometry.

Methods

Patients undergoing elective anorectal surgery with regional anaesthesia were divided randomly into three groups and received a saddle (SD), lumbar epidural (LE), or caudal (CD) block. Anorectal manometry was performed before and 30 min after each regional block. The degree of motor blockade of the anal sphincter was compared using the maximal resting pressure (MRP) and the maximal squeezing pressure (MSP).

Results

The study analysis population consisted of 49 patients (SD group, n = 18; LE group, n = 16; CD group, n = 15). No significant differences were observed in the percentage inhibition of the MRP among the three regional anaesthetic groups. However, percentage inhibition of the MSP was significantly greater in the SD group (83.6 ± 13.7%) compared with the LE group (58.4 ± 19.8%) and the CD group (47.8 ± 16.9%). In all groups, MSP was reduced significantly more than MRP after each regional block.

Conclusions

Saddle block was more effective than lumbar epidural or caudal block for depressing anal sphincter tone. No differences were detected between lumbar epidural and caudal blocks.

Intravenous Midazolam as More Effective Than Propofol for Preventing Pruritus After Intrathecal Sufentanil in Surgical Patients: A Randomized Blinded Trial

Background

Pruritus is a troublesome side effect of intrathecal opioids. Midazolam can reinforce GABA-mediated inhibition of the medullary dorsal horn neurons, and thus theoretically has potential to suppress opioid-induced pruritus.

Objectives

This prospective double-blinded randomized trial aimed at comparing the effects of propofol, midazolam, and a combination of the two on the prevention of pruritus induced by intrathecal sufentanil.

Methods

Eighty-four patients undergoing spinal anesthesia with 3 mL hyperbaric bupivacaine 0.5% and 5 μg sufentanil (1 mL) were randomly allocated to one of the three study groups: Group 1, who were administered 20 mg intravenous (IV) propofol bolus, then 50 μg/kg/min IV infusion; Group 2, who were administered 0.03 mg/kg IV midazolam bolus, then 0.02 mg/kg/h IV infusion; and Group 3, who were administered 10 mg IV propofol and 0.015 mg/kg IV midazolam bolus, then 25 μg/kg/min propofol and 0.01 mg/kg/h midazolam IV infusion. The incidence rates and severity of pruritus were assessed intraoperatively and postoperatively for 24 hours.

Results

The Ramsay Sedation Score was highest for the propofol group throughout the duration of the anesthetic process. Overall, 17 patients in the propofol group (60.7%), eight patients in the midazolam group (28.6%), and nine patients in the propofol-midazolam group (32.1%) developed pruritus (P = 0.027). Intraoperative pruritus was observed in seven patients in the propofol group (25%), two patients in the midazolam group (7.1%), and five patients in the midazolam-propofol group (17.9%) (P = 0.196). Postoperative pruritus developed in 12 patients in the propofol group (42.9%), six patients in the midazolam group (21.4%), and four patients in the midazolam-propofol group (14.3%) (P = 0.041). There was no significant difference between the groups with respect to the severity of pruritus (P > 0.05).

Conclusions

This study showed that in comparison with propofol, the administration of 0.03 mg/kg IV midazolam bolus followed by 0.02 mg/kg/h could be more effective in the prevention of intrathecal sufentanil-induced pruritus without increasing sedation and other side effects.

Determination of the median effective dose (ED50) of spinal plain ropivacaine for motor block in adults

BACKGROUND

The median effective dose (ED50) for motor blockade of spinal plain bupivacaine in adults was previously reported; however, that of ropivacaine is unknown. This study aimed to determine the ED50 for motor blockade of spinal plain ropivacaine in adults, evaluating the effect of age on this parameter.

METHODS

133 patients in need of combined spinal and epidural anesthesia were enrolled in this sequential allocation study. They were divided into 6 groups according to age: 20-30, 31-40, 41-50, 51-60, 61-70, and 71-80 years. Using the up-and-down method of Dixon, the ropivacaine dose was varied according to the preceding patient's reaction. The modified Bromage and hip motor function score was used to evaluate the degree of motor block after administration of ropivacaine. ED50 values were estimated by the method of Dixon and Massey. Other indexes, including the onset of motor block, the analgesia level, and the duration of motor block were also assessed.

RESULTS

the ED50 for motor block of intrathecal ropivacaine was 20.96 mg (95 % CI: 19.83-22.16 mg) in 20-30, 19.05 mg (95 % CI: 18.43-19.70 mg) in 31-40, 17.91 mg (95 % CI: 17.10-18.76 mg) in 41-50, 17.91 mg (95 % CI: 16.49-19.44 mg) in 51-60, 16.11 mg (95 % CI: 14.50-17.90 mg) in 61-70, and 15.75 mg (95 % CI: 13.98-17.73 mg) in 71-80 year-old patients. Maximum cephalic analgesic effects were obtained at the L4-T6 and L4-T2 levels, at 5 and 10 min, respectively, after intrathecal administration of ropivacaine in all groups.

CONCLUSION

the ED50 for motor block in spinal plain ropivacaine decreases with advancing age, indicating that age has an influence on the potency of spinal ropivacaine.

Effect of mini-dose epidural dexmedetomidine in elective cesarean section using combined spinal-epidural anesthesia: a randomized double-blinded controlled study

BACKGROUND

Combined spinal-epidural anesthesia is commonly used for elective cesarean section. Our study aimed to evaluate the effect of adding dexmedetomidine to epidural bupivacaine and fentanyl in patients undergoing elective cesarean section using combined spinal-epidural anesthesia.

METHODS

Eighty healthy women at term were randomly assigned to two groups: a control group (n = 40; "Bup/Fen group") received combined spinal-epidural anesthesia with intrathecal hyperbaric bupivacaine 5 mg and an epidural mixture of 10 mL plain bupivacaine 0.25 % and fentanyl 50 μg, whereas the study group (n = 40; "Dex/Bup/Fen group") received 1 mL epidural dexmedetomidine 0.5 µg/kg in addition. The primary outcome measure was the difference between the groups in the supplementary fentanyl analgesic required. The quality of surgical anesthesia, incidences of hypotension and bradycardia, APGAR scores, intraoperative pain assessment, and onset of postoperative pain, sedation score, and side effects were recorded.

RESULTS

There was no statistically significant difference between the groups regarding block characteristics. Significantly less intraoperative and postoperative fentanyl were required by the Dex/Bup/Fen group (P = 0.015 and P = 0.0011, respectively). There was no statistically significant difference between the groups regarding sedation score or the incidences of hypotension, nausea and vomiting, dizziness, and pruritus.

CONCLUSIONS

The addition of mini-dose epidural dexmedetomidine 0.5 µg/kg as a single injection to bupivacaine fentanyl in women undergoing elective cesarean section with combined spinal-epidural anesthesia improved intraoperative conditions and the quality of postoperative analgesia.

Isometric force dynamometer is superior to bromage score in prediction of patients' ambulation after spinal anesthesia in ambulatory surgeries

BACKGROUND

The aim of our study was to use a quantitative measure of muscle strength to identify the muscle power at which the patient can safely ambulate unassisted after spinal anesthesia.

METHODS

Twenty ASA physical status I and II patients undergoing elective perineal or lower abdominal surgery under spinal anesthesia were enrolled in the study. Spinal anesthesia was conducted using 10 mg heavy bupivacaine. The regression of motor block was assessed both qualitatively using the Bromage score and quantitatively by measuring the isometric contraction of the knee, hip, and ankle flexors every 15 minutes until the patient was able to ambulate unassisted.

RESULTS

The rate of regression of the Bromage score was faster than regression of the isometric forces at all tested joints. As the median Bromage score reached 0 (no motor blockade), the mean±SD motor power recoveries at the knee, hip, and ankle were 28.2%±16%, 45.5%±24%, and 56.3%±28 %, respectively, and only 6 of 20 patients (30%, 95% confidence interval 10%-53%) were able to walk unassisted. After 75 minutes passed, 90% of the patients (95% confidence interval 56%-99%) were able to walk unassisted with mean motor power recovery of 63.6%±20%, 82.1%±27%, and 90.2%±24% at the knee, hip, and ankle, respectively. The area under the receiver operating characteristic curves was significantly higher with isometric contraction at different joints than the Bromage score (P<0.001). In addition, isometric contraction at different joints was effective in predicting the patients' ability to walk unassisted after subarachnoid block with prediction probabilities of 0.901, 0.948, and 0.958 for the knee, hip, and ankle, respectively, as compared with 0.752 for the Bromage score (P<0.001).

CONCLUSION

Quantitative measurement of the degree of recovery of the motor power of the knee, hip, or ankle flexors is more accurate and superior to the qualitative Bromage score, as a predictor of the patient's ability to safely ambulate after spinal anesthesia. This may be recommended when assessing motor block when small-dose anesthetic solutions are used.

Minimum effective dose of spinal ropivacaine with and without fentanyl for postpartum tubal ligation

BACKGROUND

Ropivacaine may be the ideal spinal anesthetic for postpartum tubal ligation due to its medium duration of action, low incidence of side effects and possibly reduced post-anesthetic care unit (PACU) stay.

METHODS

Two prospective up-down sequential allocation studies were performed using hyperbaric spinal ropivacaine via a combined spinal-epidural anesthetic technique for patients undergoing postpartum tubal ligation. The first study was performed using an initial dose of 12.5 mg hyperbaric ropivacaine, which was adjusted in testing intervals of 0.5 mg. The second study used an initial dose of 16 mg hyperbaric ropivacaine, a testing interval of 1.0mg, and a fixed dose of fentanyl 10 μg. The need to supplement the block with intravenous or epidural agents was defined as a failure. Failures were treated with epidural lidocaine.

RESULTS

The first and second studies recruited 24 and 17 patients, respectively. The median effective dose (ED50) for hyperbaric spinal ropivacaine was 16.4 mg (95% CI 13.7-19) with an ED95 estimate of 21.9 mg. The median effective dose of spinal ropivacaine with fentanyl 10 μg was 17.0 mg (95% CI 15.4-18.7) with an ED95 estimate of 21.3 mg. When data were combined, the overall ED50 for ropivacaine was 16.7 mg (95% CI 15.1-18.4) with an ED95 estimate of 22.5 mg (95% CI 16.3-28.8). A T8 block was not achieved in 4 patients receiving spinal ropivacaine alone, and 1 patient receiving spinal ropivacaine with fentanyl. The majority (82%) of patients who did not receive epidural local anesthetic supplementation had recovery of motor block within 60 min following PACU admission.

CONCLUSION

Spinal hyperbaric ropivacaine 22 mg with or without fentanyl 10 μg could be used for postpartum tubal ligation surgery.

Estimation of the minimum motor blocking potency ratio for intrathecal bupivacaine and lidocaine

BACKGROUND

The up-down sequential allocation model has been adapted to investigate a variety of clinical and pharmacological issues in neuraxial anaesthesia including the estimation of relative potency ratios for analgesia and motor block of the most commonly used epidural and intrathecal local anaesthetics. The aim of this study was to establish the median effective doses (ED50) for motor block with intrathecal lidocaine and bupivacaine and to define the relative motor blocking potency ratio.

METHODS

In this prospective, randomised, double blind, parallel group, up-down sequential allocation study, we enrolled 71 parturients undergoing elective caesarean section under combined spinal-epidural anaesthesia. The women received either intrathecal lidocaine 2% w/v or bupivacaine 0.5% w/v. The initial dose was 4 mg for bupivacaine and 12 mg for lidocaine. Subsequent doses were determined by the outcome in the previous parturient, according to the up-down sequential allocation technique. The end point was the occurrence of any motor block in either lower limb within 5 min.

RESULTS

The intrathecal ED50 for motor block was 13.7 mg for lidocaine (95% CI, 13.1 to 14.4) and 3.4 mg for bupivacaine (95% CI, 2.6 to 4.1) (P<0.0001) and the relative motor blocking potency ratio was 4.1 (95% CI 3.3 to 5.2).

CONCLUSIONS

Intrathecal bupivacaine was 4.1 times more potent than lidocaine for motor block.

Laparoscopy-assisted subtotal gastrectomy under thoracic epidural-general anesthesia leading to the effects on postoperative micturition

BACKGROUND

Recently, the laparoscopic surgical technique has been widely applied to major surgery as it can minimize surgical incision, reduce blood loss, and shorten hospital stay. In this study, we evaluated the effectiveness of the laparoscopic surgery on postoperative micturitional function in comparison to open surgery.

METHOD

Sixty patients undergoing subtotal gastrectomy were assigned to either laparoscopic (L group, n = 30) or open surgery (O group, n = 30) groups. The combined thoracic epidural-general anesthesia was performed on all patients, and epidural patient-controlled analgesia (PCA) using ropivacaine and sufentanil was maintained for two days following surgery. After surgery, visual analog pain score (VAS), levels of sensory and motor block, observer's assessment of alertness/sedation score (OAA/S), time to first flatus, ambulation and oral intake, and micturition function were assessed.

RESULTS

The L group showed much earlier ambulation, flatus and oral intake than the O group. Although the scores of VAS and OAA/S were not significantly different between the two groups, the micturition problem scores of the L group were lower than that of the O group (P < 0.05). All patients of the L group had no difficulty in self-voiding, whereas four patients in the O group required urinary catheterization on the first postoperative day (POD1).

CONCLUSIONS

Patients who underwent laparoscopic subtotal gastrectomy had a low incidence of micturitional problem and showed early recovery. Therefore, urinary catheterization on POD1 may not be a routine procedure for those who undergo laparoscopic subtotal gastrectomy under combined thoracic epidural-general anesthesia.

Levobupivacaine caudal anesthesia in children: a randomized double-blind comparison with bupivacaine

BACKGROUND

Levobupivacaine is the pure S-enantiomer of bupivacaine. Despite obvious benefits in the event of accidental intravascular injection there has been no studies demonstrating a clinically significant benefit to levobupivacaine over racemic bupivacaine for pediatric regional anesthesia. Given the similar pharmacokinetic profiles of both drugs the studies to date have been underpowered to demonstrate what is likely to be a small difference in clinical effectiveness. Our aim was to determine if there are significant differences in the clinical effectiveness of levobupivacaine compared with racemic bupivacaine for caudal anesthesia in children having lower abdominal surgery. A secondary aim was to determine if there are differences in the incidence of postoperative motor blockade between these agents.

METHODS

Three hundred and ten children ranging in age from 1 month to 10.75 years in age having lower abdominal surgery were enrolled. Patients were randomized in a double blind manner to receive a caudal block with either 0.25% bupivacaine (n = 152) or 0.25% levobupivacaine (n = 155) to a total volume of 1 ml x kg(-1). Motor blockade (modified Bromage scale) and postoperative pain or distress (FLACC behavioral scale for postoperative pain) were measured at predetermined time points during the subsequent 120 min.

RESULTS

There were no significant adverse effects attributable to levobupivacaine. Success rates were defined as a lack of hemodynamic response to first surgical incision and low postoperative pain scores. At a mean duration of 5 min between block completion and first incision success for 1 ml x kg(-1) of 0.25% bupivacaine was 91% and 94% for 0.25% levobupivacaine. Satisfactory postoperative analgesia was present in 98% of patients after bupivacaine caudal anesthesia and 97.5% for levobupivacaine. At 30 min following caudal anesthesia the incidence of postoperative motor block with racemic bupivacaine was 84% and decreased to 7% at 120 min. For levobupivacaine motor block at 30 min postcaudal was present in 85% and decreased to 11% at 120 min.

CONCLUSIONS

Levobupivacaine is an effective agent for caudal anesthesia in children at a recommended dose of 2.5 mg x kg(-1). The rapidity of onset was suitable for establishment of surgical anesthesia and postoperative analgesia was achieved in greater than 97.5% of patients. It appears to be of equivalent potency to racemic bupivacaine in children requiring lower abdominal surgery.

Epidural test dose with levobupivacaine and ropivacaine: determination of ED 50 motor block after spinal administration

BACKGROUND

When a test is required to detect a possible intrathecal catheter, many would seek to use the same local anaesthetic as that used for epidural analgesia. The rapid onset of inappropriate motor block after a local anaesthetic administered epidurally implies intrathecal spread. Because of claims of greater sensory-motor separation, or because of reduced potency compared with bupivacaine, the efficacy of the new local anaesthetics in intrathecal testing has been questioned. The aim of this study was to establish the feasibility of a test dose for an inadvertent intrathecal catheter using ropivacaine and levobupivacaine, and to establish the dose required.

METHODS

Sixty women undergoing elective Caesarean section with a combined spinal- epidural technique were enrolled into this prospective, double-blind sequential allocation study. The women were randomized to receive plain levobupivacaine 0.5% or ropivacaine 0.5% intrathecally. The dose was determined according to up-down sequential allocation. The end-point was any evidence of lower limb motor block within 5 min of injection.

RESULTS

The ED(50) motor block at 5 min was 4.8 mg (95% CI, 4.49, 5.28) for levobupivacaine and 5.9 mg (95% CI, 4.82, 6.98) for ropivacaine (95% CI difference, 0.052, 1.98) (P=0.04). The estimated ED(95) motor block was 5.9 mg (95% CI 5.19, 6.71) for levobupivacaine and 8.3 mg (95% CI, 6.30, 10.44) for ropivacaine. The potency ratio between the two drugs was 0.83 (95% CI, 0.69, 0.99).

CONCLUSIONS

Both local anaesthetics produce evidence of motor block within 5 min of intrathecal injection and could serve as tests of intrathecal administration. Derived ED(95) values suggest 10 mg doses should be effective, but this study did not measure predictive value. Ropivacaine is less potent for motor block than levobupivacaine by a factor of 0.83 (P<0.04).

The Relative Motor Blocking Potencies of Intrathecal Ropivacaine: Effects of Concentration

This study established the median effective dose (ED(50)) for motor block of intrathecal 1% and 0.1% ropivacaine and determined the effects of the concentration of the solution injected on the motor block obtained. We enrolled into this prospective, randomized, double-blind, sequential allocation study 54 parturients undergoing elective Cesarean delivery under combined spinal-epidural technique. Parturients were randomized to receive intrathecal ropivacaine either 1% or 0.1%. The initial dose was chosen to be 4 mg, with subsequent doses being determined by the response of the previous patient (testing interval, 1 mg). The occurrence of any motor block in either lower limb within 5 min from the intrathecal injection of the study solution was considered effective. The motor block at 5 min was 6.1 mg for 1% ropivacaine (95% confidence interval [CI], 5.1-7.1) and was 9.1 mg (95% CI, 7.8-10.3) for 0.1% ropivacaine (P = 0.0013; 95% CI difference, 1.3-4.7). The relative efficacy ratio of the 2 concentrations was 1.5 (95% CI difference, 1.2-1.9) in favor of the larger concentration. The ED(50) of spinal ropivacaine to produce motor block in pregnant patients was significantly influenced by the concentration of the local anesthetic, with dose requirements being increased by 50% for the smaller concentration.

IMPLICATIONS

The minimum local anesthetic dose for motor block with 0.1% ropivacaine is 50% larger than the 1% concentration with a relative efficacy ratio of 1.5. Our findings suggest that more diluted local anesthetic solutions determine less motor block, and this may be considered in ambulant laboring parturients.

Hip-flexed postures do not affect local anaesthetic spread following induction of epidural analgesia for labour

Hip-flexed postures enlarging the pelvic diameter are used to improve the obstetric course of labour. Although most investigations show that lateral and sitting positions do not affect the spread of epidural analgesia, the effect of recently introduced hip-flexed postures has yet to be confirmed. This prospective randomised study included 93 parturients. Ropivacaine 0.1% 12 mL plus sufentanil 0.5 micrograms/mL was administered epidurally over a period of 6 min in one of four postures: sitting, right hip-flexed left lateral position, left hip-flexed right lateral position and supine 30 degrees lateral tilt as a control group. Left and right cephalad and sacral epidural spread were measured every 2 min over a period of 30 min. Pain relief, motor blockade and maternal and fetal side effects were noted. The total epidural spread was 15+/-0.3 dermatomes and the upper level of thermo-algesic blockade T7-T8 (range T3 to T10) in all groups. There were no differences between groups in left or right total spread or upper level of epidural blockade, time to maximal block or pain relief. There was no motor block nor any maternal or fetal side effects. The power of the study (1 - beta) was 93%. We conclude that, for the three hip-flexed postures tested, position does not influence local anaesthetic spread or symmetry of thermo-algesic blockade after induction of obstetric epidural analgesia.