Efficacy of intrathecal midazolam in potentiating the analgesic effect of intrathecal fentanyl in patients undergoing lower limb surgery

Comparative Analysis of Intrathecal Bupivacaine With Fentanyl Versus Intrathecal Bupivacaine With Midazolam in Lower Abdominal and Lower Limb Surgeries

Many different adjuvants are added intrathecally along with local anaesthetics to prolong intraoperative and postoperative analgesia. Hence, this study aimed to compare intrathecal bupivacaine with fentanyl and bupivacaine with midazolam in lower abdominal and lower limb surgeries. Following permission from the Hospital Ethical Committee (Research Protocol No.: IESC/PGS/2022/143), the study was conducted on a sample of 60 patients, divided into two groups, Group F and Group M, with 30 patients each, representing the American Society of Anaesthesiologist's (ASA) grades I and II. The patients were between the ages of 18 and 60 and featured both males and females, scheduled to undergo elective surgical procedures on the lower abdomen and lower limbs via spinal anaesthesia. Group "F": 3 ml of 0.5% hyperbaric bupivacaine hydrochloride with 0.5 ml (25 mcg) of fentanyl (preservative-free) intrathecally. Group "M": 3 ml of 0.5% hyperbaric bupivacaine hydrochloride with 0.5 ml (2.5 mg) of midazolam (preservative-free) intrathecally. The primary aim was to study the onset of motor and sensory block and duration of analgesia with the addition of midazolam or fentanyl to 0.5% heavy bupivacaine in the sub-arachnoid block. A secondary aim was to evaluate the quality of anaesthesia and postoperative analgesia, determine the haemodynamic stability in the intraoperative and postoperative period in the two study groups, and observe any adverse effects of study drugs. Group F exhibited a substantially longer duration for both sensory (211.5 vs. 154.4 min) and motor blockade (269.8 vs. 214.6 min) compared to Group M, as well as a rapid onset time for both sensory (2.6 vs. 3.3 min) and motor blockade (3.1 vs. 3.9 min). Also, Group F had a significantly longer duration of effective analgesia compared to Group M (266 ± 15.9 vs. 197.6 ± 13.7 minutes). The addition of 0.5 ml (2.5 mg) Midazolam with 0.5% hyperbaric Bupivacaine intrathecally prolonged the duration of anaesthesia and postoperative analgesia; however, fentanyl 0.5 ml (25 mcg) has a more prolonged duration of intraoperative and postoperative analgesia.

Comparison of Fentanyl With Midazolam As Adjuvants to Levobupivacaine in Spinal Anesthesia for Cesarean Sections: A Randomized Controlled Trial

Background and objectives Spinal anesthesia stands as a cornerstone for patients undergoing lower segment cesarean section (LSCS), offering advantages like faster onset and high block density. Levobupivacaine, known for its high potency and long-acting nature, has a slower onset. The safety of intrathecal fentanyl or midazolam is evaluated as an adjuvant to levobupivacaine in parturients. This study aims to compare the duration of postoperative analgesia provided by fentanyl or midazolam added to 0.5% hyperbaric levobupivacaine in elective cesarean sections. Secondary objectives include evaluating the onset and duration of sensory and motor blockade and the incidence of nausea and vomiting. Identifying the more effective adjuvant will help optimize spinal anesthesia protocols, improve postoperative outcomes, and enhance patient comfort and recovery. Methods This study was conducted at SRM Medical College Hospital and Research Centre, Chennai, India, over six months (May 1, 2023, to October 1, 2023). A total of 90 patients undergoing elective LSCS received spinal anesthesia in a prospective randomized double-blinded controlled trial. Patients were allocated to three groups: Group A received levobupivacaine with fentanyl, Group B received levobupivacaine with midazolam, and Group C received levobupivacaine with normal saline. Block characteristics, postoperative analgesia, hemodynamic stability, and complications were assessed. Assessments were conducted at specified time points: intraoperatively, every five minutes for the first 30 minutes, every 10 minutes for the next hour, every two hours for six hours, and every four hours up to 24 hours postoperatively. Statistical analysis utilized one-way analysis of variance (ANOVA). Results Group B (levobupivacaine with midazolam) exhibited a shorter time to sensory block onset (88 seconds) compared to Groups A and C (both 145 seconds) (p < 0.001). Group A (levobupivacaine with fentanyl) showed a shorter time to maximum motor block (p = 0.045) than Groups B and C. The sensory block duration was significantly longer in Group A (127.5 minutes) compared to Group B (60 minutes) and Group C (69 minutes) (p < 0.001). Motor block duration was also prolonged in Group A (251 minutes) compared to Group B (147 minutes) and Group C (177 minutes) (p = 0.045). The first analgesic requirement was delayed in Group A (248 minutes), whereas Groups B (115 minutes) and C (90 minutes) (p < 0.001) required more frequent analgesia. Group A experienced a higher incidence of postoperative nausea and vomiting. Conclusion Midazolam accelerated sensory block onset, while fentanyl prolonged anesthesia duration without significantly affecting motor block. Fentanyl delayed the first analgesic requirement, whereas midazolam reduced postoperative nausea, vomiting, and shivering.

Epidural administration of ropivacaine and midazolam is superior to intra-articular administration as postoperative analgesia after isolated arthroscopic anterior cruciate ligament reconstruction with hamstrings autograft: a randomized controlled clinical trial

OBJECTIVE

Reconstructive surgery of the anterior cruciate ligament (ACL) is quite common, previous studies have documented that adequate pain control in the early phases of the postoperative period translates into early mobility and a rapid start of rehabilitation. Therefore, the search for new strategies for postoperative pain control is justified. The aim of this study was to compare intra-articular to the epidural administration of ropivacaine and midazolam as postoperative analgesia after arthroscopic ACL reconstruction with hamstring autograft (HA).

MATERIAL AND METHODS

Double-blinded, prospective randomized clinical trial included 108 consecutive patients aged from 18 to 50 years that had undergone arthroscopic ACL reconstruction with HA. The patients were randomly assigned to 2 groups. The first group received intraarticular ropivacaine and midazolam. The second group received epidural ropivacaine and midazolam. The need for rescue analgesia, the postoperative pain experienced, side effects and complications of the analgesic drugs were evaluated.

RESULTS

The intra-articular group received statistically significantly higher mean doses of rescue analgesia on the first two days (2.8 ​± ​1.0 vs. 1.3 ​± ​0.6 in the epidural group; p ​= ​0.001). Visual Analogue Scale scores at flexion were statistically significantly higher in the intra-articular group over the entire study period. The intra-articular group also reported a statistically significantly lower range-of-motion 87 ​± ​15 vs. 102 ​± ​11 in the epidural group (p ​= ​0.001).

CONCLUSIONS

Epidural administration of ropivacaine combined with midazolam in patients undergoing primary ACL reconstruction with HA was clinically and significantly better relative to rescue analgesia and the intensity of pain in the first 48 postoperative hours when compared to intraarticular administration. There was no difference in terms of adverse effects and complications.

LEVEL OF EVIDENCE: 2

Adding intrathecal midazolam to local anesthetics improves sensory and motor block and reduces pain score without increasing side effects in lower limb surgeries: A meta-analysis and systematic review

This meta-analysis was done to investigate the role of intrathecal midazolam in lower limb surgeries regarding prolongation of spinal block, postoperative pain control and associated side effects. The included studies reported onset and duration of sensory and motor block, time to first request analgesia, 24h opioid consumption, postoperative pain control, and associated side effects following use of intrathecal midazolam for lower limb surgeries. This review was performed following the PRISMA guidelines and using the online databases, Medline, Science Direct, Google scholar and Cochrane library. We registered this review with the PROSPERO database (ID-CRD42022346361) in August 2022. A total of 10 randomised controlled trials were included in this meta-analysis. Our results showed patients receiving 1mg intrathecal midazolam showed significantly faster onset of sensory block [P=.001 (CI: -0.98, -0.31)]. Duration of sensory and motor block were also significantly prolonged in intrathecal midazolam group [P<.00001 (CI: 18.08, 39.12), P=.002 (CI: 0.45, 2). Intrathecal midazolam also increased the time to first request analgesia [P=.0003, (CI: 1.22, 4.14)]. Pain scores at 4 and 12h postoperatively were significantly lower in patients receiving intrathecal midazolam [P=.00001 (CI: -1.20, -0.47) and P=.05 (CI: -0.52, -0.01) respectively]. In conclusion, the addition of intrathecal midazolam to local anesthetics in lower limb surgeries results in early onset of sensory and motor block. It also increases the duration of sensory and motor block. The time to first request analgesia is increased. VAS pain scores at 4 and 12h postoperatively were also lower without any increased side effects.

Comparison of the effect of adding midazolam versus fentanyl to intrathecal levobupivacaine in patients undergoing cesarean section: double-blind, randomized clinical trial

BACKGROUND

Many adjuvants are added to prolong the effects of spinal analgesia. We investigated the postoperative analgesic efficacy of the addition of midazolam or fentanyl to intrathecal levobupivacaine in women undergoing cesarean delivery.

METHODS

Eighty patients were randomly assigned to two groups (n = 40). Group M received 10 mg of 0.5% levobupivacaine plus 2 mg of midazolam. Group F received 10 mg of 0.5% levobupivacaine plus 25 μg of fentanyl. Assessments included motor and sensory block, APGAR score, time to first request for analgesia, postoperative pain score, total consumption of rescue analgesics, and adverse effects.

RESULTS

Sensory blockade was prolonged in Group M compared with Group F (215.58 ± 27.94 vs. 199.43 ± 19.77 min; p = 0.004), with no differences in other characteristics of the spinal block in intraoperative hemodynamics or APGAR score. The mean time to first request for rescue analgesia was longer in Group M (351.45 ± 11.05 min) than in Group F (268.83 ± 10.35 min; p = 0.000). The median total consumption of rescue analgesics in the first 24 hours postoperatively was 30 mg in Group M vs. 60 mg in Group F (p = 0.003). The median Visual Analog Scale (VAS) scores were lower in Group Ethan in Group F from the 8th to the 12th hour postoperatively, with no differences between the groups at other time points. The incidence of adverse effects was higher in Group F than in Group M.

CONCLUSION

Intrathecal midazolam (2 mg) was superior to intrathecal fentanyl (25 μg) in increasing the duration of the sensory blockade and postoperative analgesia with lower postoperative pain scores and decreasing the incidence of adverse effects.

Addition of Dexmedetomidine and Fentanyl to Intrathecal Hyperbaric Bupivacaine for Lower Limb Surgeries: A Randomized, Comparative Study

BACKGROUND AND AIM

There is an unmet need to prolong analgesia duration following regional anesthesia; dexmedetomidine as an adjuvant for the intrathecal block has gained popularity over the last few years. The present study compares the onset, duration of sensory and motor block, postoperative analgesia, hemodynamic changes, and adverse effect of dexmedetomidine or fentanyl as an adjuvant to hyperbaric bupivacaine administered intrathecally.

METHODS

With approvals, 60 American Society of Anesthesiologists (ASA) physical status I and II adult patients undergoing lower limb surgeries under subarachnoid block were randomized to receive either 5 µg dexmedetomidine (group BD, n=30) or 25 μg fentanyl (group BF, n=30) intrathecally along with 12.5 mg hyperbaric bupivacaine. The time to onset of sensory and motor blockade, time to peak block, intraoperative hemodynamic variations, duration of postoperative analgesia, and associated intraoperative and postoperative complications, if any, were recorded and compared statistically. SPSS v16 (IBM Corp., New York, United States) was used, and P<0.05 was considered significant.

RESULTS

The onset of sensory block in group BD was 1.54 ±0.38 minutes and 3.4 ± 0.40 minutes (P<0.001) in group BF. Time taken for the sensory level to reach T10 in group BD was 3.11± 0.43 minutes and 5.55 ± 0.60 minutes (P<0.001) in group BF. Time taken for two-segment regression in group BD was 160.06 ± 6.85 minutes and 110.4 ± 6.03 minutes (P<0.001) in group BF. The onset of motor block was 2.58 ± 0.437 minutes in group BD and 4.43 ± 0.43 minutes (P<0.001) in group BF. The total duration of analgesia in group BD was 365.8 ± 24.76 minutes and 213.33 ± 20.19 minutes (P<0.001) in group BF. Minimum intraoperative hemodynamic variations were found in group BD, and two groups had comparable side effects.

CONCLUSION

Dexmedetomidine 5 μg added to intrathecal bupivacaine produced early-onset and prolonged block compared with fentanyl 25 μg. No significant attributable adverse effects were noted for both the drugs except the fall in blood pressure, which was gradual in dexmedetomidine but a steep fall in fentanyl.

Nalbuphine versus Midazolam as an Adjuvant to Intrathecal Bupivacaine for Postoperative Analgesia in Patients Undergoing Cesarean Section

Background and Purpose

Adding adjuvants to intrathecal hyperbaric bupivacaine provides long analgesic duration with less adverse effects. The aim of this study was to compare intrathecal nalbuphine versus midazolam in patients undergoing cesarean section.

Clinical Trial ID

NCT03918187.

Patients and Methods

This was a prospective randomized controlled study conducted on 90 females undergoing cesarean section under spinal anesthesia who were randomly allocated to three equal groups of 30 patients each: group C received hyperbaric bupivacaine 12.5 mg plus 0.5 mL saline, group N received hyperbaric bupivacaine 12.5 mg plus 1 mg nalbuphine, group M received hyperbaric bupivacaine 12.5 mg plus 2.5 mg midazolam. The onset and duration of sensory and motor block, effective analgesic time, analgesic requirements, adverse effects, sedation, and Apgar scores were recorded.

Results

There was significant rapid onset of sensory and motor block (1.95±.44 and 3.50±0.43 min) with slower regression of sensory block and time to bromage I (211.6±13.2 and 219.8±20.2 min) in group N compared to groups M, C (p < 0.001), with statistically significant rapid onset and long duration of both blocks in group M compared to C (p<0.001). The effective analgesic time was significantly prolonged in group N (263.7±16.3) compared to groups M and C (224.2 ± 18.6, 185.5±17.45), respectively, (p<0.001) and prolonged in group M compared to C (p<0.001), with increase in analgesic requirement in group C compared to groups N and M (p<0.001) and no significant difference between groups N and M. There was higher sedation score in groups N, M (1.78±0.63, 2.75±0.54), respectively, compared to group C (0.61±0.12) (p<0.001) with lower Apgar score in group M (6.9±0.73) at one minute than in groups N, C (7.1±0.91, 7.7±0.84) (p<0.001). There was no significant difference between groups regarding the adverse effects.

Conclusion

Adding 1 mg nalbuphine to 12.5 mg hyperbaric bupivacaine provided more effective postoperative analgesia than adding 2.5 mg midazolam, with less non-significant adverse effects in midazolam group in patients undergoing elective cesarean section.

Use of intrathecal midazolam or fentanyl as an adjunct to spinal anaesthesia with bupivacaine for lower limb surgery: A randomised controlled study

Background

Intrathecal adjuncts have been used to prolong the quality and duration of subarachnoid anaesthesia. Midazolam given intrathecally is reported to have antinociceptive properties. The purpose of this study was to compare intrathecal midazolam with fentanyl for pain relief and patient comfort.

Methods

In this prospective, double-blind, randomised controlled trial, 90 patients for lower limb surgeries were randomly allocated to three groups: "control group" (3 ml 0.5% heavy bupivacaine), "fentanyl group" (3 ml 0.5% bupivacaine + 10 mcg fentanyl) and "midazolam group" (3 ml 0.5% bupivacaine + 1 mg midazolam). Level, duration, and quality of blocks were compared along with the duration and quality of postoperative analgesia. Haemodynamic stability and any associated complications were also noted.

Results

Onset of block was fastest in Group C (28.5 ± 13.48 min) vis-a-vis other groups (35.5 ± 26.05 min for Group "F" and 28.5 ± 23.68 min for Group "M"; P = 0.51). Duration of block was comparable in all groups (130.5 ± 39.3 min Group "C"; 126.5 ± 44.0 min Group "F" and 129.5 ± 45.7 min Group "M"; P > 0.5).Addition of adjuncts did not significantly defer the appearance of pain. Intensity of pain was lower in Group "M". Average VAS scores were lower for Group "M" (3-4) than those for Group "C" (4-5) and Group "F" (4-6).Majority of patients required at least one dose of rescue analgesic; however, those receiving fentanyl reported better quality of postoperative analgesia than those in midazolam group.

Conclusion

Adjuvants improve quality of postoperative analgesia (fentanyl better than midazolam).