The Effects of Premedication With Three Different Doses of Intravenous Dexmedetomidine on Spinal Anesthesia: A Randomized Comparative Study

BACKGROUND

Intravenous dexmedetomidine is one of the commonly preferred techniques for sedation during any regional procedure. However, only a very few studies compared the impact of different bolus doses during spinal anesthesia, and none for our geographical area.

MATERIALS AND METHODS

A total of 60 patients were allocated into either of the three groups (group I, II, III) to receive intravenous dexmedetomidine 0.5, 0.75, and 1 mcg/kg, respectively. The primary outcome was to compare the duration of sensory and motor blockade and the secondary outcomes were the level of sedation, hemodynamic stability, duration of analgesia, and the side effects, if any.

RESULTS

Two-dermatome regression time and the duration of motor block were significantly higher in groups II and III when compared to group I. However, the difference in duration of analgesia, Ramsay sedation scores, bradycardia, and hypotension was statistically insignificant between the groups.

CONCLUSION

Intravenous dexmedetomidine in doses of 0.75 and 1 mcg/kg significantly prolongs the two-dermatome regression time and duration of the motor block when compared to 0.5 mcg/kg dose. Hence, it is better to titrate the dose between 0.75 and 1 mcg/kg, as the administration of bolus intravenous Dex in doses ranging between 0.75 and 1 mcg/kg appears to provide adequate intraoperative block characteristics while maintaining hemodynamic stability without any significant respiratory depression or other adverse effects.

High-volume patient-controlled epidural vs. programmed intermittent epidural bolus for labour analgesia: a randomised controlled study

The aim of neuraxial analgesia is to achieve excellent pain relief with the fewest adverse effects. The most recently introduced technique for epidural analgesia maintenance is the programmed intermittent epidural bolus. In a recent study, we compared this with patient-controlled epidural analgesia without a background infusion and found that a programmed intermittent epidural bolus was associated with less breakthrough pain, lower pain scores, higher local anaesthetic consumption and comparable motor block. However, we had compared 10 ml programmed intermittent epidural boluses with 5 ml patient-controlled epidural analgesia boluses. To overcome this potential limitation, we designed a randomised, multicentre non-inferiority trial using 10 ml boluses in each group. The primary outcome was the incidence of breakthrough pain and total analgesic intake. Secondary outcomes included motor block; pain scores; patient satisfaction; and obstetric and neonatal outcomes. The trial was considered positive if two endpoints were met: non-inferiority of patient-controlled epidural analgesia with respect to breakthrough pain; and superiority of patient-controlled epidural analgesia with respect to local anaesthetic consumption. A total of 360 nulliparous women were allocated randomly to patient-controlled epidural analgesia-only or programmed intermittent epidural bolus groups. The patient-controlled group received 10 ml boluses of ropivacaine 0.12% with sufentanil 0.75 μg.ml^-1 ; the programmed intermittent group received 10 ml boluses supplemented by 5 ml patient-controlled boluses. The lockout period was 30 min in each group and the maximum allowed hourly local anaesthetic/opioid consumption was identical between the groups. Breakthrough pain was similar between groups (11.2% patient controlled vs. 10.8% programmed intermittent, p = 0.003 for non-inferiority). Total ropivacaine consumption was lower in the PCEA-group (mean difference 15.3 mg, p < 0.001). Motor block, patient satisfaction scores and maternal and neonatal outcomes were similar across both groups. In conclusion, patient-controlled epidural analgesia is non-inferior to programmed intermittent epidural bolus if equal volumes of patient-controlled epidural analgesia are used to maintain labour analgesia and superior with respect to local anaesthetic consumption.

Evaluation of the Effect of Intravenous Dexamethasone on the Duration of Spinal Anaesthesia in Parturients Undergoing Lower Segment Caesarean Section

Introduction Dexamethasone is shown to prolong the duration of nerve blocks when administered perineurally as well as intravenously. The effect of intravenous dexamethasone on the duration of hyperbaric bupivacaine spinal anesthesia is lesser known. We conducted a randomized control trial to determine the effect of intravenous dexamethasone on the duration of spinal anesthesia in parturients undergoing lower-segment cesarean section (LSCS). Methods Eighty parturients planned for LSCS under spinal anesthesia were randomly allocated to two groups. Patients in group A were administered dexamethasone intravenously, and group B received normal saline intravenously before spinal anesthesia. The primary objective was to determine the effect of intravenous dexamethasone on the duration of sensory and motor block after spinal anesthesia. The secondary objective was to determine the duration of analgesia and complications in both groups. Result The total duration of the sensory and motor blocks in group A was 118.38 ± 19.88 minutes and 95.63 ± 19.91 minutes, respectively. The entire sensory and motor blockade duration in group B was 116.88 ± 13.48 minutes and 97.63 ± 15.15 minutes, respectively. The difference between the groups was found to be statistically insignificant. Conclusion Intravenous 8 mg dexamethasone in patients planned for LSCS under hyperbaric spinal anesthesia does not prolong the sensory or motor block duration compared to placebo.

Erector spinae plane block versus fascia iliaca block after total hip arthroplasty: a randomized clinical trial comparing analgesic effectiveness and motor block

Background

Ultrasound-guided, supra-inguinal fascia iliaca block (FIB) provides effective analgesia after total hip arthroplasty (THA), but is complicated by high rates of motor block. The erector spinae plane block (ESPB) is a promising motor-sparing technique. In this study, we test the analgesic superiority of FIB over ESPB, while also comparing motor impairment.

Methods

In this randomized, observer-blinded clinical trial, patients scheduled for THA with spinal anesthesia were randomly assigned to receive either ultrasound-guided FIB or ESPB preoperatively. Primary outcome was morphine consumption at 24 hours after surgery. Secondary outcomes were: pain scores; assessment of sensory and motor block; incidence of postoperative nausea and vomiting and other complications; and development of chronic post-surgical pain.

Results

Sixty patients completed the study. There were no statistically-significant differences in morphine consumption at 24 hours (p = 0.68) or pain scores at any time point. FIB produced more reliable sensory block in the femoral nerve (p = 0.001) and lateral femoral cutaneous nerve (p = 0.018) distributions. However, quadriceps motor strength was better preserved in the ESPB group when compared to the FIB group (p = 0.002). No differences were observed for hip adduction motor strength (p = 0.253). No differences between groups were observed in terms of side effects or chronic pain incidence.

Consclusions

ESPB may represent a promising alternative to FIB for postoperative analgesia after THA. ESPB and FIB offer similar opioid-sparing benefits within the first day after surgery, but ESPB results in less quadriceps motor impairment.

Isobaric forms of ropivacaine vs. bupivacaine in lower abdominal surgeries: a hospital-based, prospective, comparative study

We aimed to assess whether ropivacaine (0.75%; 22.5 mg) can replace bupivacaine (0.5%; 15 mg) as a better intrathecal anesthetic in lower abdominal surgery. In this hospital-based, single-blind, randomized, prospective, comparative study, 100 patients of either sex, aged between 18 and 70 years, weighing 40-80 kg, with American Society of Anesthesiologists physical status 1 and 2, and undergoing lower abdominal surgery were randomly allocated into two groups to receive intrathecal isobaric bupivacaine 0.5% 3 mL (15 mg) or ropivacaine 0.75% 3 mL (22.5 mg). In the intraoperative period, the onset, efficacy, duration, and regression of sensory and motor blockade and the quality of anesthesia and hemodynamic effects were observed at regular intervals. The ropivacaine and bupivacaine groups were comparable for demographic parameters. The duration of onset of sensory and motor blocks was significantly shorter in the bupivacaine group (P < 0.01). In the ropivacaine group, a faster recovery from sensory block (P = 0.02) and higher segmental height [thoracic (T)10 and T8] were achieved (P < 0.01). Bradycardia and hypotension were insignificant in the ropivacaine group (P > 0.05). Isobaric ropivacaine is a better spinal anesthetic in lower abdominal surgeries as it provides faster recovery from sensory block and a higher level of segmental sensory block with fewer side-effects.

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].

Transmuscular Quadratus Lumborum Block versus Infrainguinal Fascia Iliaca Nerve Block for Patients Undergoing Elective Hip Replacement: A Double-blinded, Pilot, Randomized Controlled Trial

Purpose

Transmuscular quadratus lumborum (TQL) block has been described as an effective option for postoperative analgesia in patients undergoing hip replacement with single injection described as providing analgesia for up to 24 h. We hypothesize that a TQL block, when compared to fascia iliaca block (FIB), will provide better analgesia and less motor block in the initial 24-h postoperative period.

Patients and Methods

Fifty patients undergoing elective hip replacement surgery, ASA I–III, were included in the study. Patients were randomized into two groups. Patients in group A received spinal anesthesia followed by FIB. Patients in group B received spinal anesthesia followed by TQLB. Postoperative pain scores and motor block were assessed at 6 and 24 hours. The primary outcome measure was 24 h total morphine consumption. Secondary outcome measures included pain score (VNS) and motor block (modified Bromage scale) at 6 and 24 h postoperatively.

Results

There was no statistical difference in morphine consumption between the two groups (p-value 0.699). There was no difference in pain scores at 6 h (p-value 0.540) or 24 h (p-value 0.383). There was no difference in motor block at 6 h (p-value 0.497) or at 24 h (p-value 0.773).

Conclusion

Transmuscular quadratus lumborum block along with spinal anesthesia for patients undergoing elective hip replacement surgery does not reduce opioid consumption or motor weakness when compared to fascia iliaca block. The results and conclusion apply to a dose of 20 mL of 0.25% bupivacaine used in each group.

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].

Comparing intravenous dexmedetomidine and clonidine in hemodynamic changes and block following spinal anesthesia with ropivacaine in lower limb orthopedic surgery: a randomized clinical trial

Dexmedetomidine (DEX) can prolong duration of anesthesia and shorten onset of sensory and motor block relative to clonidine. This study attempted to compare the efficacy of intravenous DEX and clonidine for hemodynamic changes and block after spinal anesthesia with ropivacaine in lower limb orthopedic surgery. In a double-blind randomized clinical trial, 120 patients undergoing spinal anesthesia in lower limb orthopedic surgery were recruited and divided into three groups using balanced block randomization: DEX group (n = 40; intravenous DEX 0.2 µg/kg), clonidine group (n = 40; intravenous clonidine 0.4 µg/kg), and placebo group (n = 40; intravenous normal saline 10 mL) in which pain scores were assessed using visual analogue scales (at recovery, and 2, 4, 6, and 12 hours after surgery) and time to achieve and onset of sensory and motor block. Statistically significant differences were found in mean arterial pressure among the groups at all times except baseline (P = 0.001), with a less mean arterial pressure and a prolonged duration of sensory and motor block (P = 0.001) in the DEX group where pain relieved in patients immediately after surgery and at above mentioned time points (P = 0.001). Simultaneous administration of intravenous DEX with ropivacaine for spinal anesthesia prolongs the duration of sensory and motor block and relieves postoperative pain, and however, can decrease blood pressure. Although intravenous DEX as an adjuvant can be helpful during spinal anesthesia with ropivacaine, it should be taken with caution owing to a lowering of mean arterial pressure in patients especially in the older adults. This study was approved by Ethical Committee of Arak University of Medical Sciences (No. IR.Arakmu.Rec.1395.450) in March, 2017, and the trial was registered and approved by the Iranian Registry of Clinical Trials (IRCT No. IRCT2017092020258N60) in 2017.

Hyperbaric prilocaine vs. hyperbaric bupivacaine for spinal anaesthesia in women undergoing elective caesarean section: a comparative randomised double-blind study

Hyperbaric bupivacaine spinal anaesthesia remains the gold standard for elective caesarean section, but the resultant clinical effects can be unpredictable. Hyperbaric prilocaine induces shorter motor block but has not previously been studied in the obstetric spinal anaesthesia setting. We aimed to compare duration of motor block after spinal anaesthesia with prilocaine or bupivacaine during elective caesarean section. In this prospective randomised, double-blind study, women with uncomplicated pregnancy undergoing elective caesarean section were eligible for inclusion. Exclusion criteria included: patients aged < 18 years; height < 155 cm or > 175 cm; a desire to breastfeed; or a contra-indication to spinal anaesthesia. Patients were randomly allocated to two groups: the prilocaine group underwent spinal anaesthesia with 60 mg intrathecal prilocaine; and the bupivacaine group received 12.5 mg intrathecal heavy bupivacaine. Both 2.5 µg sufentanil and 100 µg morphine were added to the local anaesthetic agent in both groups. The primary outcome was duration of motor block, which was assessed every 15 min after arriving in the post-anaesthetic care unit. Maternal haemodynamics, APGAR scores, pain scores, patient satisfaction and side-effects were recorded. Fifty patients were included, with 25 randomly allocated to each group. Median (IQR [range]) motor block duration was significantly shorter in the prilocaine group, 158 (125-188 [95-249]) vs. 220 (189-250 [89-302]) min, p < 0.001. Median length of stay in the post-anaesthetic care unit was significantly shorter in the prilocaine group, 135 (120-180 [120-230]) vs. 180 (150-195 [120-240]) min, p = 0.009. There was no difference between groups for: maternal intra-operative hypotension; APGAR score; umbilical cord blood pH; maternal postoperative pain; and patients' or obstetricians' satisfaction. We conclude that hyperbaric prilocaine induces a shorter and more reliable motor block than hyperbaric bupivacaine for women with uncomplicated pregnancy undergoing elective caesarean section.

Effects of adding dexmedetomidine, fentanyl, and verapamil to 0.5% ropivacaine on onset and duration of sensory and motor block in forearm surgeries: a randomized controlled trial

This study was aimed to compare the onset and duration of axillary block with ropivacaine 0.5% plus either dexmedetomidine, fentanyl, or verapamil in forearm surgeries. This double-blind clinical trial enrolled three equal-sized block-randomized groups of patients (n = 105) scheduled for hand and forearm surgery at Arak, Iran in 2019, who received: (i) ropivacaine (40 mL/0.5%) + dexmedetomidine (1 μg/kg), (ii) ropivacaine (40 mL/0.5%) + fentanyl (1 μg/kg), and (iii) ropivacaine (40 mL/0.5%) + verapamil (2.5 mg), respectively. We recorded some vital signs such as mean arterial pressure, heart rate and oxygen saturation, onset of complete sensory and motor block, duration of the block, opioid use, as well as pain score at recovery and certain time points (2, 4, 6, 12, and 24 hours post-operation). Adding dexmedetomidine to ropivacaine (40 mL/0.5%) prolonged the duration of sensory (P = 0.001) and motor block (P = 0.001) in compared to adding fentanyl and verapamil and it also shortens the time to onset of sensory (P = 0.001) and motor block (P = 0.001). There is a significant difference between three groups in terms of visual analog scale mean and the lowest pain score was obtained in the dexmedetomidine group (P = 0.001), significant time trend (P = 0.001), as well as the time and groups interaction (P = 0.001). Dexmedetomidine was concluded to be associated with alleviated pain; reduced opioid use; short onset of sensory block; and prolonged duration of sensory and motor block. It hence is recommended to lengthen the duration of axillary block and to help relieve postoperative pain and ultimately to move to cut down the postoperative opioid use in forearm surgery. The study was approved by the Ethical Committee of Arak University of Medical Sciences (approval No. IR.ARAKMU. REC.1397.266), and registered on Iranian Registry of Clinical Trials (registration No. IRCT20141209020258N111) on May 9, 2019.

Efficacy of premixed versus succedent administration of fentanyl and bupivacaine in subarachnoid block for lower limb surgeries: A randomised control trial

Background and Aims

Subarachnoid block is the most commonly used anaesthesia technique for lower limb surgeries. Opioids are the most commonly used adjuvants with local anesthetics (LA). Adjuvants are given premixed with LA loaded in a single syringe. This study was conducted to evaluate differences in level of sensory and motor block and incidence of hypotension whilst administering hyperbaric bupivacaine and fentanyl either in a single syringe or different syringes. The effect of administering opioid prior to LA and vice versa on these parameters was also assessed.

Methods

One hundred and twenty patients were randomly allocated into three groups of 40 each: Group A received premixed 0.5% heavy bupivacaine 2.5 ml (12.5 mg) and 0.5 ml (25 microgram) of fentanyl in a single 3.0 ml syringe, Group B received 0.5 ml (25 microgram) of fentanyl in a 3.0 ml syringe followed by 0.5% heavy bupivacaine 2.5 ml (12.5 mg) in a 3.0 ml syringe, Group C received 0.5% heavy bupivacaine 2.5 ml (12.5 mg) in a 3.0 ml syringe followed by 0.5 ml (25 microgram) fentanyl in a 3.0 ml syringe. All statistical calculations were done using SPSS 21 version statistical program for Microsoft Windows.

Results

The mean time for onset of sensory and motor block was least in group C followed by group B. The duration of sensory and motor block was prolonged in groups B and C. Patients in group A experienced more hypotension as compared to groups B and C.

Conclusion

Administering hyperbaric bupivacaine first followed by fentanyl leads to an early onset and prolonged duration of sensory and motor block.

Programmed intermittent epidural bolus vs. patient-controlled epidural analgesia for maintenance of labour analgesia: a two-centre, double-blind, randomised study†

The programmed intermittent epidural bolus technique has shown superiority to continuous epidural infusion techniques, with or without patient-controlled epidural analgesia for pain relief, reduced motor block and patient satisfaction. Many institutions still use patient-controlled epidural analgesia without a background infusion, and a comparative study between programmed intermittent epidural bolus and patient-controlled epidural analgesia without a background infusion has not yet been performed. We performed a randomised, two-centre, double-blind, controlled trial of these two techniques. The primary outcome was the incidence of breakthrough pain requiring a top-up dose by an anaesthetist. Secondary outcomes included: motor block; pain scores; patient satisfaction; local anaesthetic consumption; and obstetric and neonatal outcomes. We recruited 130 nulliparous women who received initial spinal analgesia, and then epidural analgesia was initiated and maintained with either programmed intermittent epidural bolus or patient-controlled epidural analgesia using ropivacaine 0.12% with sufentanil 0.75 µg·ml^-1 . The programmed intermittent epidural bolus group had a programmed bolus of 10 ml every hour, with on-demand patient-controlled epidural analgesia boluses of 5 ml with a 20 min lockout, and the patient-controlled epidural analgesia group had a 5 ml bolus with a 12 min lockout interval; the potential maximum volume per hour was the same in both groups. The patients in the programmed intermittent epidural bolus group had less frequent breakthrough pain compared with the patient-controlled epidural analgesia group, 7 (10.9%) vs. 38 (62.3%; p < 0.0001), respectively. There was a significant difference in motor block (modified Bromage score ≤ 4) frequency between groups, programmed intermittent epidural bolus group 1 (1.6%) vs. patient-controlled epidural analgesia group 8 (13.1%); p = 0.015. The programmed intermittent epidural bolus group had greater local anaesthetic consumption with fewer patient-controlled epidural analgesia boluses. Patient satisfaction scores and obstetric or neonatal outcomes were not different between groups. In conclusion, we found that a programmed intermittent epidural bolus technique using 10 ml programmed boluses and 5 ml patient-controlled epidural analgesia boluses was superior to a patient-controlled epidural analgesia technique using 5 ml boluses and no background infusion.

Intrathecal Use of Isobaric Levobupivacaine 0.5% Versus Isobaric Ropivacaine 0.75% for Lower Abdominal and Lower Limb Surgeries

Background

This study was undertaken to compare and evaluate the efficacy of 3-ml 0.5% isobaric levobupivacaine versus 3-ml 0.75% isobaric ropivacaine in patients undergoing elective lower abdominal and lower limb surgeries.

Methods

We allocated 60 patients into two groups (n=30 each) to receive either a spinal block of 3-ml 0.5% isobaric levobupivacaine (group L) or 3-ml 0.75% isobaric ropivacaine (group R). Haemodynamic parameters were measured intraoperatively till the end of surgery and postoperatively for two hours. The onset and duration of sensory block and motor block were recorded. Adverse events were also recorded. The student’s unpaired t-test was used for comparing the continuous variables.

Results

The mean age in group L was 37.83 ±16.51 years and the mean age in group R was 38.50 ±12.97 years. The mean onset of sensory block in group L (6.97 ±1.82 mins) was significantly faster than in group R (8.47 ±2.55 mins), p<0.05. Similarly, so was the mean onset of motor block in group L (10.27 ±1.92 mins) versus group R (12.93 ±2.55 mins), p<0.05. The mean duration of sensory block in group L (147.63 ±27.53 mins) was significantly longer than in group R (97.40 ±12.38 mins), p<0.05, as was the mean duration of motor block in group L (207.33 ±22.27 mins) versus group R (146.60 ±21.22 mins), p<0.05. In group L, 13.3% of patients had complications, with hypotension being the most common (6.7%); in group R, 40% had complications, of which bradycardia was the most common (13.3%).

Conclusion

There was an earlier onset of sensory and motor block and prolonged duration of sensory and motor block with intrathecal administration of 3-ml 0.5% isobaric levobupivacaine as compared to 3-ml 0.75% isobaric ropivacaine. Haemodynamic parameters were more stable with levobupivacaine than ropivacaine. Adverse effects were more common with ropivacaine.

Effect of different doses of intrathecal dexmedetomidine on hemodynamic parameters and block characteristics after ropivacaine spinal anesthesia in lower-limb orthopedic surgery: a randomized clinical trial

The study aims to compare the efficacy of different doses of intrathecal dexmedetomidine on hemodynamic parameters and block characteristics after ropivacaine spinal anesthesia in lower-limb orthopedic surgery. In a double-blind trial, 90 patients undergoing spinal anesthesia for lower-limb orthopedic surgery were included and then randomly assigned to three groups; dexmedetomidine 5 μg/kg, dexmedetomidine 10 μg/kg and placebo. Blood pressure, heart rate, and oxygen saturation were recorded in the three groups at the first 15 minutes and then every 15 to 180 minutes at recovery by a resident anesthesiologist, as well as sensory-motor block onset. The visual analog scale scores for the assessment of pain were recorded at recovery, and 2, 4, 6, and 12 hours postoperatively and the data were analyzed by Stata software. The onset and time to achieve sensory block to ≥ T8 were faster in the 10 μg/kg dexmedetomidine group than the other groups (P = 0.001). The Bromage score was higher in the 10 μg/kg dexmedetomidine group (P = 0.0001) with lower pain score as compared with the 5 μg/kg dexmedetomidine and placebo groups (P = 0.0001). Therefore, an increase in dexmedetomidine hastens the onset of sensory-motor block but not causes side effects. This study was approved by the Ethical Committee of Arak University of Medical Sciences in 2017 (Ethical Code: IR.ARAKMU.REC.1396.37), and the trail was registered and approved by the Iranian Registry of Clinical Trials in 2017 (IRCT No. IRCT2017070614056N12).

Clinical Comparison of Adding Sulfate Magnesium and Dexmedetomidine in Axillary Plexus Block for Prolonging the Duration of Sensory and Motor Block: Study Protocol for a Double-blind Randomized Clinical Trial

BACKGROUND

The purpose of this study was to compare the effect of magnesium sulfate adjunct to dexmedetomidine on increasing the duration of sensory and motor block in axillary block.

MATERIALS AND METHODS

This study is a double-blind clinical trial. Ninety-nine patients were included in the study. They were undergoing forearm and hand surgery and were referred to Vali-e-Asr Hospital in Arak. The patients were divided into three groups. The first group received lidocaine (1.5%) and dexmedetomidine (0.5 μg/kg). The second group patients were given lidocaine (1.5%) plus magnesium. In the control group, lidocaine (1.5%) was adjusted to 35 cc with normal saline. The final volume was 35 cc in the three groups. Sensory and motor block and pain were measured and data were analyzed using SPSS v. 20. The final volume was 35 cc in the three groups.

RESULTS

The sensory and motor block onset time and the stabilization time of the sensory and motor block in the magnesium sulfate group were lower (p<0/001). Pain in recovery, 2, 4, 6, 12, and 24 hours after surgery was lower in the magnesium sulfate group when compared with the dexmedetomidine group (p<0.001). The lowest dose of opioid was used in the dexmedetomidine group 24 hours after surgery (p<0.001).

CONCLUSION

The results showed that dexmedetomidine decreases pain. Magnesium sulfate increased the sensory and motor block onset time, and the sensory and motor block stabilization time, but dexmedetomidine increases the motor block duration.

Adductor canal block: Effect of volume of injectate on sciatic extension

Context:

Spread of local anesthetic within adductor canal to peroneal and tibial nerves is described in literature. This spread could be volume-dependent.

Aims:

In this study, we compared the diffusion of two volumes of 0.375% ropivacaine to popliteal fossa.

Settings and Design:

This was a prospective, randomized controlled, single-blind study conducted in Kassab Orthopaedic Institute of Tunis for 1 year (2018).

Materials and Methods:

A total of 42 patients, American Society of Anesthesiologists I/II scheduled for knee arthroscopy under spinal anesthesia scheduled to receive adductor canal block, were randomized into two groups: group N received 20 mL of ropivacaine 0.375% and group H received 40 mL. We evaluated sensory motor blocks of both peroneal and tibial nerves at 30 and 60 min.

Statistical Analysis Used:

Chi-square or Fisher's exact test was used to compare the number and percentage. P <0.05 was significant.

Results:

At 60 min, complete sensory block of the peroneal nerve was obtained for 16 patients in group H versus 15 patients in group N with no statistically significant difference (P = 0.60). The difference was also not significant (P = 0.27) for the tibial nerve: 14 patients for group H versus 16 for group N. Motor blockade was rare in the two nerve territories.

Conclusion:

Spread of 0.375% ropivacaine to popliteal fossa resulted in high rate of complete sensory blockade of both peroneal and tibial nerves. Diffusion of local anesthetic was not volume-dependent.

A Comparative Study of Intrathecal Bupivacaine and Bupivacaine with Different Doses of Clonidine in Lower Limb Surgeries

Background:

Intrathecal clonidine is a very safe, nonopioid adjuvant to local anesthetics to prolong the duration of analgesia without any major side effects.

Objective:

The purpose of the present study was to evaluate the efficacy of clonidine in two different doses as an adjuvant to bupivacaine intrathecally in lower limb surgeries.

Materials and Methods:

A total of 75 adult patients scheduled to undergo lower limb surgeries were randomly allocated into either of three groups of 25 patients. Group I received 12.5 mg bupivacaine, Group II patients received bupivacaine 12.5 mg with clonidine 15 μg, and patients in Group III received bupivacaine 12.5 mg with clonidine 30 μg intrathecally. A total volume of 3 ml was made in all groups using normal saline. The hemodynamic parameters, onset, and duration of sensory block, highest dermatomal level of sensory block, motor block onset, time to complete motor block recovery, and mean time to request of the first analgesic were recorded. Side effects or any other complications were noted.

Results:

The mean time of onset of sensory block and motor block was less in clonidine groups. The mean duration of sensory block was significantly prolonged in clonidine groups as compared to study group. The duration of motor block (in minutes) was significantly prolonged in Group III (171.60 ± 38.20) as compared to Group I (113.20 ± 35.79) and Group II (115.20 ± 38.41). The time of analgesic request in Group I was 148.16 ± 43.99 min, 190.60 ± 38.08 in Group II, and 200.80 ± 59.85 min in Group III.

Conclusions:

The addition of intrathecal clonidine 15 μg to small dose bupivacaine increased the spread, duration of analgesia, and produced effective spinal anesthesia with stable hemodynamics and did not prolong postoperative motor block.

Freezing of Swallowing

Background

Swallowing deficits and freezing phenomena represent severe parkinsonian features. Freezing as a symptom occurring during swallowing has not been reported on yet.

Methods

We report on 3 patients with probable PSP-parkinsonism (PSP-P) who manifested freezing of swallowing (FOS).

Results

All 3 patients experienced severe weight loss in recent months. At examination, 1 patient had freezing of gait. Video fluoroscopy showed nonfunctional trembling movements of the tongue and palate during chewing and volitional swallowing, with a 6- to 8-Hz frequency that is typical for freezing episodes during walking and finger tapping. These freezing episodes were accompanied by impaired oral bolus transportation. The pharyngeal phase was not relevantly affected.

Conclusions

FOS represents a novel disease feature of PSP-P. The feature may have fundamental, but potentially treatable, consequences for patients' health and quality of life and may be considered in patients with degenerative parkinsonism who experience severe and unexplained weight loss.

Comparative study of two doses of intrathecal dexmedetomidine as adjuvant with low dose hyperbaric bupivacaine in ambulatory perianal surgeries: A prospective randomised controlled study

Background and Aims:

Dexmedetomidine (DMT), as intrathecal adjuvant has been shown to successfully prolong duration of analgesia but delay the motor recovery. Hence, this study was designed to find out the dose of DMT which can provide satisfactory analgesia without prolonging motor block.

Methods:

A total of 50 patients scheduled for elective perianal surgeries were randomly allocated to Groups C or D (n = 25). Group D received hyperbaric bupivacaine 0.5% 4 mg + DMT 5 μg and Group C received hyperbaric bupivacaine 0.5% 4 mg + DMT 3 μg intrathecally. Onset and duration of sensory and motor blockade, duration of analgesia, time for ambulation and first urination were recorded. Adverse effects if any were noted.

Results:

Demographic characters, duration of surgery were comparable. The onset of sensory block to S1 was 9.61 ± 5.53 min in Group C compared to 7.69 ± 4.80 min in Group D (P = 0.35). Duration of sensory (145.28 ± 83.17 min – C, 167.85 ± 93.75 min – D, P = 0.5) and motor block (170.53 ± 73.44 min – C, 196.14 ± 84.28 min, P = 0.39) were comparable. Duration of analgesia (337.86 ± 105.11 min – C, 340.78 ± 101.81 min – D, P = 0.9) and time for ambulation (252.46 ± 93.72 min – C, 253.64 ± 88.04 min – D, P = 0.97) were also comparable. One patient in each group had urinary retention requiring catheterization. No other side effects were observed.

Conclusion:

Intrathecal DMT 3 μg dose does not produce faster ambulation compared to intrathecal DMT 5 μg though it produces comparable duration of analgesia for perianal surgeries.

A comparative study between intrathecal dexmedetomidine and fentanyl as adjuvant to intrathecal bupivacaine in lower abdominal surgeries: A randomized trial

Context:

Spinal anesthesia is preferred choice of anesthesia in lower abdominal surgeries since long time. However problem with this is limited duration of action, so for long duration surgeries alternative are required. Dexmedetomidine is a highly selective alpha-2-adrenergic agonist has property to potentiate the action of local anesthetic used in spinal anesthesia. Fentanyl is an opioid and it has also the same property.

Aims:

To compare the efficacy, analgesic effects, and side-effects of dexmedetomidine and fentanyl as adjuvant to bupivacaine for lower abdominal surgery.

Settings and Design:

The type of this study was double-blind randomized trial.

Subjects and Methods:

A total of 80 patients were randomly allocated in two Group D and Group F. Group D were injected injection bupivacaine 0.5% heavy × 3.0 ml + 0.5 ml of preservative free normal saline containing 5 μg dexmedetomidine. Group F were received injection bupivacaine 0.5% heavy × 3.0 ml + 0.5 ml fentanyl equivalent to 25 μg.

Statistical Analysis Used:

The statistical analysis was performed using SPSS (Statistical Package for Social Sciences) version 15.0 statistical analysis software.

Results:

The results show that highest sensitivity level of T6 and T8 was achieved by higher proportion of subjects from Group D when compared to Group F and sensitivity level T7 was achieved by higher proportion of subjects of Group F when compared to Group D. Duration of analgesic properties was significantly higher in Group D when compared to Group F.

Conclusion:

The findings in the present study suggested that intrathecal adjuvant use of dexmedetomidine as compared to fentanyl provides a longer sensory and motor blockade and also prolongs the postoperative analgesic effect.

Anesthetic effects of adding intrathecal neostigmine or magnesium sulphate to bupivacaine in patients under lower extremities surgeries

BACKGROUND

Regional anesthesia is widely used to perform different surgical procedures including those performed on the extremities. In this study, the anesthetic effects of adding intrathecal neostigmine or magnesium sulphate to bupivacaine in patients under lower extremities surgeries were assessed.

MATERIALS AND METHODS

In this double-blind randomized clinical trial, 90 patients, candidate for lower extremities surgeries in a training hospital, were recruited. The patients with ASA class I and II aging from 20 to 65 years between 2009 and 2010 were evaluated. The selected patients were randomly assigned to receive either bupivacaine alone (Group A, n=30), or bupivacaine plus magnesium sulphate 50% (Group B, n=30), or bupivacaine plus neostigmine (Group C, n=30). Then sensory and motor onset and complete block and the time of recovery were measured.

RESULTS

The sensory block onset time were 3.03 ± 0.981 in group A, 3.90 ± 2.71 in group B and 3.7 ± 1.08 in group C and knee flexion time were not significantly different among the three groups (P > 0.05), whereas the time to complete motor block was significantly longer in group C and motor recovery time were significantly different between groups (P=0.001).

CONCLUSIONS

According to the obtained results, it may be concluded that magnesium sulphate is a safe and effective adjuvant for increasing the onset time of motor block.

Regional intravenous anesthesia in knee arthroscopy

OBJECTIVE

The goal of the study was to investigate the regional intravenous anesthesia procedure in knee arthroscopy and to evaluate the effects of adding ketamine over the anesthesia block charactery and tourniquet pain.

MATERIAL/METHOD

Forty American Society of Anesthesiologists (ASA) II patients who received knee arthroscopy were enrolled. After monitoring, a peripheral IV line was inserted.The venous blood in the lower extremity was evacuated with a bandage, and the proximal cuff of the double-cuff tourniquet was inflated. The patients were randomly split into two groups. While Group P received 80 ml 0.5% prilocaine, Group PK received 0.15 mg/kg ketamine (80 ml in total) via the dorsum of the foot. We recorded onset time of the sensory block, end time of the sensory block, presence of the motor block, the time when the patient verbally reported tourniquet pain and surgical pain, duration of tourniquet tolerance, fentanyl consumption during the operation, time to first analgesic requirement, methemoglobin values at 60 minutes, operative conditions, 24-hour analgesic consumption, discharge time, and hemodynamic parameters.

RESULTS

The body mass index (BMI) of the patients who required general anesthesia was significantly higher than the BMI of other patients. The onset time of the sensory block was shorter for those in Group PK, but the time to first analgesic requirement was longer.

CONCLUSION

Regional intravenous anesthesia using the doses and volumes commonly used in knee arthroscopy may be an inadequate block among patients with high BMI values. Moreover, the addition of ketamine to the local anesthetic solution may produce a partial solution by shortening the onset of sensory block and prolonging the time until the first analgesic is required.