Spinal Ropivacaine for Lower Limb Surgery: A Dose–Response Study

Effect of single spinal anesthesia with two doses ropivacaine on urinary retention after hemorrhoidectomy in male patients

Background

Anorectal diseases are common in the population and include internal, external, and mixed hemorrhoids. Although hemorrhoid surgery is a brief operation, anesthesia, anesthetic drugs, drug concentrations, and anesthesia level control are closely related to postoperative uroschesis. For hemorrhoid surgery, a single spinal block with ropivacaine is commonly used that blocks the S2-S4 parasympathetic nervous system, which in turn governs the voiding reflex, causing postoperative urinary retention; this affects the recovery of patients. This study was performed to investigate the effects of two doses ropivacaine that provided satisfactory analgesia and muscle relaxation and inhibited adverse reflexes on urinary retention after hemorrhoidectomy.

Methods

The study included 200 male patients who underwent anorectal surgery with American Society of Anesthesiologists (ASA) grade I-II single elective spinal anesthesia between March 2021 and March 2022. Patients were randomly assigned to 2 groups using a random number table: Group A (n = 100) received 10 mg 0.5% ropivacaine (1.5 ml 1% ropivacaine + 1.5 ml 10% glucose = 3 ml), and Group B (n = 100) received 15 mg 0.5% ropivacaine (1.5 ml 1% ropivacaine + 1.5 ml 10% glucose = 3 ml).

Results

The anal sphincter exhibited good relaxation, and no obvious traction pain or significant difference in the time of muscle strength recovery was observed between the 10 mg and 15 mg 0.5% ropivacaine groups (P > 0.05). The 10 mg 0.5% ropivacaine group had shorter time of micturition exceeding 100 ml and lower voiding International Prostate Symptom Score than the 15 mg 0.5% ropivacaine group (P < 0.01).

Conclusions

Single spinal anesthesia with 10 mg 0.5% ropivacaine not only provides satisfactory anesthetic effect for hemorrhoidectomy but also has less influence on postoperative uroschesis and is worthy of clinical application.

Trial registration

The study was registered in the Chinese Clinical Trial Registry (http://www.chictr.org.cn; identifier: ChiCTR2,100,043,686) on February 27, 2021.

Comparing the minimum local anesthetic dose of ropivacaine in real-time ultrasound-guided spinal anesthesia and traditional landmark-guided spinal anesthesia: a randomized controlled trial of knee surgery patients

Background

Through previous studies and clinical practice, we have found that real-time ultrasound-guided (UG) spinal anesthesia (SA) and traditional landmark-guided (LG) SA each require a different minimum local anesthetic dose (MLAD) of ropivacaine. For this study, we used Dixon’s up-and-down sequential method to analyze and compare the MLAD of different ropivacaine concentrations required for the UG and LG SA methods.

Methods

A total of 120 patients undergoing knee surgery were consecutively recruited and randomly divided into four groups (30 patients per group). These groups were categorized as follows: Group I: high ropivacaine ultrasound-guided (HRUG), Group II: low ropivacaine ultrasound-guided (LRUG), Group III: high ropivacaine landmark-guided (HRLG), and Group IV: low ropivacaine landmark-guided (LRLG). SA was established by a bolus administration of up-and-down doses of 0.75% or 0.5% plain ropivacaine. Initial doses of 16, 18, 12, and 14 mg were administered to groups I–IV, and after that, increased or decreased by 1.5 mg according to dose effectiveness. Upon identifying the intervertebral puncture level, a lumbar X-ray was performed with metal markers, and actual radiographic findings were identified and compared to the initial markings.

Results

For UG groups, the MLAD in the LRUG group was significantly higher than in the HRUG group [20.192 mg (95% CI, 19.256–21.174) versus 17.176 mg (95% CI, 16.276–18.124), respectively; P<0.001]. For LG groups, the MLAD in the LRLG group was significantly higher than in the HLRG group [14.478 mg (95% CI, 13.364–15.500) versus 13.201 mg (95% CI, 11.959–14.571), respectively; P=0.047]. When comparing both high ropivacaine groups (HRGs: I/III) to the low ropivacaine groups (LRGs: II/IV), we found that both UG subgroups (I/II) had a significantly higher MLAD than LG subgroups (III/IV) (P<0.001). US identified L4–5 in up to 90% of cases. Comparatively, palpation was successful in only 33.3% of patients. The rates of cephalad localization by US and palpation were 6.67% vs. 66.67%, respectively (P=0.002).

Conclusions

We found a higher MLAD of ropivacaine was required for UG SA at the L4–5 level due to the method providing a more accurate (less cephalad) localization than traditional LG SA.

Trial Registration

Chinese Clinical Trial Registry ChiCTR2000033158.

Comparative Evaluation of Three Different Doses of Spinal Isobaric Ropivacaine in Patients Undergoing Day Care Perineal Surgeries: A Randomized Double-blind Study

Background and objective:

Ropivacaine owing to its propensity of causing motor blockade of reduced duration, is preferred for ambulatory day care surgery. Intrathecal ropivacaine has shown effective analgesia for lower limb surgery. Our study plans to evaluate spinal ropivacaine in three different doses in patients undergoing day care perineal surgery.

Methodolgy:

90 ASA-I patients scheduled to undergo day care perineal surgery were randomized to receive intrathecal ropivacaine. Group I (n=30) received 15mg of intrathecal ropivacaine, Group II (n=30) received 18.75 mg of intrathecal ropivacaine and Group III (n=30) received 22.5 mg of intrathecal ropivacaine. Onset of sensory block at T 10, peak sensory block level, duration of sensory block, onset and duration of motor block and relevant safety data were recorded.

Result:

Onset of analgesia was significantly shorter in Group III (3.5 min ; P <0.0001). However, time taken for peak sensory blockade was comparable in group II and III (12.76 and 11.93 mins). Duration of analgesia was longer and statistically significant in Group III (201.6 mins: P <0.0001) when compared to Group I and II. Onset of motor block was observed to be shortest in Group III (6.7 mins) and duration of motor block was longest in Group III (153.73 mins). These two parameters were statistically significant than Group I and II (P <0.0001).

Conclusion:

Intrathecal ropivacaine in a dose of 18.75 and 22.5 mg were observed to be equally effective in providing satisfactory analgesia. However, higher dose was associated with profound sensory and motor block.

Ropivacaine: Anesthetic consideration in elderly patients for transurethral resection of prostrate a clinical trial

Background:

Ropivacaine has less systemic toxicity and greater differentiation of sensory and motor blockade after subarachnoid block. This study was aimed to evaluate the anesthetic efficacy of intrathecal 0.75% isobaric ropivacaine alone or with fentanyl in elderly patients undergoing transurethral resection of prostrate.

Materials and Methods:

Fifty four elderly consented patients of ASA grade I-III scheduled for transurethral resection of prostrate under the subarachnoid block were randomized to receive either intrathecal 4 mL of 0.75% isobaric ropivacaine (Group R, n = 27) or 3.5 mL of 0.75% isobaric ropivacaine with 0.5 mL (25 μg) of fentanyl (Group RF, n = 27). The characteristics of sensory and motor blockade, intraoperative hemodynamic changes, and secondary effects were noted for evaluation.

Results:

There was no significant difference in the demographic profile of patients. The surgical anesthesia was adequate for TURP surgery in all patients. The median time to achieve the sensory blockade at T10 dermatome was 3.2 ± 1.5 min in Group R and 3.5 ± 1.3 min in Group RF. The median duration of sensory blockade at T10 was 130.6 ± 10.2 min in Group R and 175.8 ± 8.6 min in Group RF. The median duration of complete motor block was significantly shorter than the duration of sensory blockade (P < 0.001). There were fewer episodes of manageable hypotension in 5 patients of Group R and 11 patients of Group RF. No secondary effects have occurred in any patients.

Conclusion:

The intrathecal 0.75% isobaric ropivacaine alone or with fentanyl has provided effective surgical anesthesia for transurethral resection of prostrate and hemodynamic stability in elderly patients.

Update on the clinical utility and practical use of ropivacaine in Chinese patients

We reviewed the Chinese and English literature for efficacy and tolerability data as well as pharmacological properties of ropivacaine in Chinese patients. Ropivacaine is a long-acting amide local anesthetic agent that elicits nerve block via reversible inhibition of sodium ion influx in nerve fibers. The available evidence in the literature on anesthesia practice indicates that ropivacaine produces equally surgical sensory block and postoperative and obstetrics analgesia with good maternal and fetal outcome to those of bupivacaine or levobupivacaine. It appears to be associated with comparable onset, quality, and duration of sensory block, but with a lower incidence or grade of motor block, compared to bupivacaine. The satisfaction of both patients and surgeons is high when ropivacaine is used. Thus, ropivacaine appears to be an important option for regional anesthesia and for the management of postoperative and labor pain, with its enhanced sensorimotor differentiation blockage at lower concentrations and enhanced safety at higher concentrations.

Comparison of intrathecal ropivacaine-fentanyl and bupivacaine-fentanyl for major lower limb orthopaedic surgery: A randomised double-blind study

Background and Aims:

Intrathecal bupivacaine results in complete anaesthetic block of longer duration than ropivacaine. Fentanyl as an adjuvant may improve the quality of spinal block of ropivacaine while maintaining its advantage of early motor recovery. In this study, we proposed to compare the efficacy and safety of intrathecal ropivacaine-fentanyl (RF) with bupivacaine-fentanyl (BF) for major lower limb orthopaedic surgeries.

Methods:

Sixty patients were randomly allocated to receive either intrathecal 15 mg 0.5% ropivacaine with 25 mcg fentanyl (Group RF) or 15 mg 0.5% bupivacaine with 25 mcg fentanyl (Group BF). The onset, duration, spread of sensory and motor block, haemodynamic parameters and side effects were recorded. Statistical Package for Social Sciences 20 software was used for statistical analysis.

Results:

Time to reach highest sensory level and complete motor block were comparable. Sensory regression to L1 dermatome was 226 ± 46.98 min in Group RF and 229.33 ± 50.51 min in Group BF, P = 0.36. The motor recovery to Bromage scale 1 was faster in Group RF (242.8 ± 47.06 min) than Group BF (268 ± 49.9 min) P = 0.023. Time for rescue analgesia was prolonged in Group BF (263.33 ± 63 min) when compared to Group RF (234.44 ± 58.76 min), P = 0.021. The haemodynamic stability was better in Group RF than Group BF.

Conclusion:

Intrathecal RF provided satisfactory anaesthesia with haemodynamic stability for major lower limb orthopaedic surgery. It provided similar sensory but shorter duration of motor block compared to BF which is a desirable feature for early ambulation, voiding and physiotherapy.

A comparative evaluation of hyperbaric ropivacaine versus hyperbaric bupivacaine for elective surgery under spinal anesthesia

Background:

Recently introduced ropivacaine is 40% less potent than bupivacaine. Ropivacaine made hyperbaric by the addition of dextrose is known to provide reliable spinal anesthesia (SA). This study was designed to compare the clinical efficacy of equal doses of hyperbaric 0.5% ropivacaine with 0.5% bupivacaine for SA.

Materials and Methods:

Eighty American Society of Anesthesiologists grade I-II patients undergoing elective infraumbilical surgeries under SA were recruited and randomized to receive 3ml of hyperbaric ropivacaine 5mg/ml containing dextrose 83 mg/ml (by the addition of desired dose of 25% dextrose) in Group R or 3ml of hyperbaric bupivacaine 5mg/ml containing dextrose 80 mg/ml in Group B. Monitoring of vitals and observation for the block parameters were carried out. The data were presented as mean with a standard deviation and frequency with percentage. Statistical analysis was performed using InStat computer software with appropriate tests and P < 0.05 was considered to be significant.

Results:

Ropivacaine produced a slower onset of sensory block (ropivacaine 4.5 min; bupivacaine 3.2 min; P < 0.05) and the mean total duration of sensory block was significantly lesser (ropivacaine155 min; bupivacaine 190.5 min; P < 0.05). Patients in the ropivacaine Group R had significantly more rapid recovery from the motor blockade (ropivacaine120 min; bupivacaine 190 min; P < 0.05) and passed urine sooner than the patients in bupivacaine Group B (ropivacaine 257 min; bupivacaine 358 min; P < 0.05).

Conclusion:

Ropivacaine 15 mg in dextrose 8.3% provides reliable SA of shorter duration than bupivacaine 15 mg in 8% dextrose.

Intrathecal fentanyl as an adjuvant to 0.75% isobaric ropivacaine for infraumbilical surgery under subarachnoid block: A prospective study

Background:

Subarachnoid blockade can be used in all surgical procedures carried out on the infraumbilical region. This study was aimed to evaluate the clinical efficacy and safety of intrathecal fentanyl as an adjuvant to 0.75% isobaric ropivacaine on onset, duration, intensity, and recovery time of sensory and motor blockade of subarachnoid block for infra umbilical surgery.

Methods:

One hundred sixty adult consented patients of either gender with American Society of Anesthesiologist ASA I and II scheduled for infraumbilical surgery were randomized into two groups of 80 patients each to receive either intrathecal study solution of 4 mL of 0.75% ropivacaine with 0.4 mL of 0.9% sodium chloride (Group I-Ropivacaine Control Group RC) or fentanyl (20 μg) (Group II-Ropivacaine with Fentanyl RF). The end points were hemodynamic variability, onset of analgesia at T 10, maximum sensory analgesic level, time to complete motor blockade, duration of sensory and motor blockade and adequacy of surgical anesthesia. The post-spinal nausea and vomiting, shivering, pruritus, respiratory depression or any other side-effects were also assessed. At the end of study, data were systematically complied and analyzed for statistically significance.

Result:

The intrathecal fentanyl has accelerated the onset time to achieve sensory blockade to T10 dermatome and motor blockade. Small dose of intrathecal fentanyl with ropivacaine has prolonged the duration of analgesia in the early post-operative period when compared with intrathecal ropivacaine alone. The intraoperative hemodynamic variability showed no statistically significant differences between groups.

Conclusion:

Intrathecal fentanyl as an adjuvant to 0.75% isobaric ropivacaine demonstrated better clinical profile as compared to ropivacaine alone.

Hypobaric spinal anesthesia with ropivacaine plus sufentanil for traumatic femoral neck surgery in the elderly: a dose-response study

BACKGROUND

In this randomized, prospective trial, we sought to determine the effective dose of hypobaric ropivacaine with sufentanil providing 95% success (ED95) in spinal anesthesia for traumatic femoral neck surgery in the elderly.

METHODS

Sixty-eight elderly patients with unilateral hip fracture randomly received 6, 8, 10, or 12 mg spinal hypobaric ropivacaine combined with 5 µg sufentanil. Patients remained in a lateral position for 15 minutes after spinal injection. The dose was considered successful if a unilateral sensory block >T12 was achieved, and there was no need for additional analgesia or conversion to general anesthesia. The ED95 was determined using logit analysis. The incidence of severe and very severe hypotension (systolic blood pressure decrease by >30% and >40% baseline, respectively) and the use of remifentanil were compared among groups using χ(2) test for trend.

RESULTS

Three patients were excluded because of failure to reach the subarachnoid space. No differences in baseline demographic data were observed among groups. The ED95 for hypobaric ropivacaine was determined to be 9 mg (95% confidence interval, 8-14). Increasing doses of ropivacaine (6, 8, 10, and 12 mg) demonstrated a positive trend with respect to incidence of hypotension (53%, 47%, 87%, and 81%, P = 0.0004) and a negative trend with respect to the use of remifentanil (41%, 12%, 0%, and 0%, P = 0.0004). A significant difference in the level of sensory block (P < 0.0001) was observed among operative and nonoperative sides but not among ropivacaine dosing groups (P = 0.16). No difference in motor blockade, incidence of very severe hypotension, total dose of ephedrine, duration of surgery, patient satisfaction, operating conditions, or surgeon satisfaction scores was observed among groups. No cases of bradycardia were observed. No patient had a preoperative sensory level <T12 after 15 minutes in the lateral decubitus position, and no cases were converted to general anesthesia. There was no difference in undesirable outcomes or postoperative troponin values among groups.

CONCLUSIONS

The effective dose of hypobaric ropivacaine combined with sufentanil 5 µg providing 95% success in spinal anesthesia for traumatic femoral neck surgery in the elderly is ED95 = 9 mg (95% confidence interval, 8-14). Using doses exceeding the ED95 may increase the incidence of hypotension. If doses less than the ED95 are chosen, the use of additional analgesia may be necessary.

Polyanalgesic Consensus Conference 2012: recommendations for the management of pain by intrathecal (intraspinal) drug delivery: report of an interdisciplinary expert panel

INTRODUCTION

The use of intrathecal (IT) infusion of analgesic medications to treat patients with chronic refractory pain has increased since its inception in the 1980s, and the need for clinical research in IT therapy is ongoing. The Polyanalgesic Consensus Conference (PACC) panel of experts convened in 2000, 2003, and 2007 to make recommendations on the rational use of IT analgesics based on preclinical and clinical literature and clinical experiences.

METHODS

The PACC panel convened again in 2011 to update the standard of care for IT therapies to reflect current knowledge gleaned from literature and clinical experience. A thorough literature search was performed, and information from this search was provided to panel members. Analysis of published literature was coupled with the clinical experience of panel members to form recommendations regarding the use of IT analgesics to treat chronic pain.

RESULTS

After a review of literature published from 2007 to 2011 and discussions of clinical experience, the panel created updated algorithms for the rational use of IT medications for the treatment of neuropathic pain and nociceptive pain.

CONCLUSIONS

The advent of new algorithmic tracks for neuropathic and nociceptive pain is an important step in improving patient care. The panel encourages continued research and development, including the development of new drugs, devices, and safety recommendations to improve the care of patients with chronic pain.

The median effective dose of bupivacaine, levobupivacaine, and ropivacaine after intrathecal injection in lower limb surgery

BACKGROUND

Intrathecal anesthesia is commonly used for lower limb surgery. Bupivacaine, levobupivacaine, and ropivacaine have all been used as intrathecal drugs, but their relative potency in this context has not been fully determined. In this study, we determined the median effective dose (ED(50)) of these three local anesthetics for intrathecal anesthesia in lower limb surgery and hence their relative potencies.

METHODS

Seventy-five patients scheduled for lower limb surgery under combined spinal-epidural anesthesia were randomly allocated to one of three groups receiving intrathecal bupivacaine, levobupivacaine, or ropivacaine. The dose of local anesthetic was varied using up-down sequential allocation technique. The dose for the first patient in each group was 8 mg, and the dosing increment was set at 1 mg. Subsequent doses in each group were determined by the outcome in the previous patient using success or failure of the spinal anesthesia as the primary end point. A success was recorded if a bilateral T12 sensory block to cold was attained within 20 min after intrathecal injection, and the surgery proceeded successfully until at least 50 min after the intrathecal injection without supplementary epidural injection. The ED(50) was calculated using the method of Dixon and Massey.

RESULTS

The ED(50)s were 5.50 mg for bupivacaine (95% confidence interval [CI]: 4.90-6.10 mg), 5.68 mg for levobupivacaine (95% CI: 4.92-6.44 mg), and 8.41 mg for ropivacaine (95% CI: 7.15-9.67 mg) in intrathecal anesthesia. The relative anesthetic potency ratios are 0.97 (95% CI: 0.81-1.17) for levobupivacaine/bupivacaine, 0.65 (95% CI: 0.54-0.80) for ropivacaine/bupivacaine, and 0.68 (95% CI: 0.55-0.84) for ropivacaine/levobupivacaine.

CONCLUSION

This study suggests that in intrathecal anesthesia for lower limb surgery, ropivacaine is less potent than levobupivacaine and bupivacaine, whereas the potency is similar between levobupivacaine and bupivacaine.