Perioperative analgesia with subarachnoid fentanyl-bupivacaine for cesarean delivery

Cesarean Sections Under Spinal Anaesthesia: Comparison of Varying Doses of Dexmedetomidine Combined with 0.75% Hyperbaric Ropivacaine: A Double-Blind Randomized Trial

Objective

The primary aim of this study was to evaluate the effects of 5 μg, 7.5 μg, and 10 μg doses of dexmedetomidine added to hyperbaric 0.75% ropivacaine on the duration of analgesia during cesarean section. Furthermore, the onset of sensory and motor block, hemodynamics, sedation, and adverse effects were investigated.

Methods

A total of 120 full-term parturients scheduled for cesarean section under spinal anaesthesia were randomized into three groups. Group RD5 received intrathecal hyperbaric 0.75% ropivacaine 15 mg (2 mL) plus dexmedetomidine 5 μg (0.5 mL), group RD7.5 received intrathecal hyperbaric 0.75% ropivacaine 15 mg (2 mL) plus dexmedetomidine 7.5 μg (0.5 mL), and group RD10 received intrathecal hyperbaric 0.75% ropivacaine 15 mg (2 mL) plus dexmedetomidine 10 μg (0.5 mL). Sensorimotor blockade characteristics, analgesia duration, hemodynamic variables, and adverse events were documented. Student's t-test and the chi-square test were used for data analysis.

Results

In groups RD5, RD7.5, and RD10, the onset of sensory block was 2.96±1.32 min, 2.26±1.50 min, and 1.96±0.93 min, respectively, while the onset of motor block was 9.63±0.11 min, 8.63±0.58 min, and 6.40±0.14 min, respectively. The duration of analgesia was significantly prolonged in group RD10 compared with groups RD7.5 and RD5 (483.43±76.21 vs. 398.74±73.59 vs. 362.58±79.87 min, respectively, P=0.001). Group RD10 also exhibited significantly higher incidences of sedation, bradycardia, and vomiting.

Conclusion

We conclude that increasing dexmedetomidine doses decreases the onset of sensory and motor blockade while prolonging analgesia duration in a dose-dependent manner.

The effect of intrathecal pethidine on post-spinal anesthesia shivering after cesarean section: a systematic review and meta-analysis

Background

Spinal anesthesia is the most preferred method for cesarean section (C-section). This meta-analysis was performed to determine the effect of low and high intrathecal doses of pethidine on the maternal outcomes after C-section.

Methods

A systematic search of PubMed, Scopus, Cochrane Library, and Google Scholar was performed. Random-effects meta-analysis was performed to derive odds ratios (ORs) from dichotomous data.

Results

Seventeen randomized controlled trials with 1304 C-section patients were included. Patients who had received intrathecal pethidine experienced decreased shivering and intensity of shivering (OR 0.13; P<0.001) and (OR 0.21; P<0.001), respectively. Moreover, vomiting (OR 2.47; P=0.002) and pruritus (OR 5.92; P<0.001) were significantly higher in the pethidine group. There was no statistically significant difference in the incidence of nausea (OR 2.55; P=0.06) and hypotension (OR 0.91; P=0.67).

Conclusions

Intrathecal pethidine can effectively decrease shivering, although it increases the risk of vomiting and pruritus. No significant difference was found both in the maternal hypotension and nausea.

A Comparison of Subarachnoid Block Characteristics Following Co-administration of Fentanyl Premixed With Hyperbaric Bupivacaine Versus Antecedent or Succedent to Hyperbaric Bupivacaine: A Randomized Controlled Study

Background Adjuvants are often used during subarachnoid block to enhance and prolong the analgesia and decrease the adverse effects of high doses of local anesthetic agents. Intrathecal fentanyl premixed with hyperbaric bupivacaine has been used in spinal anesthesia and compared with the sequential use of these drugs in separate syringes. However, given the paucity of literature, we conducted this study where premixed antecedent and succedent administration of intrathecal fentanyl with hyperbaric bupivacaine were compared in terms of flow dynamics, block characteristics, and hemodynamic alterations. Methodology This prospective, randomized, triple-blinded comparative study was conducted among 160 patients who were randomly allocated into four groups. Group A (n = 40) (control) received 3.0 mL (15 mg) of 0.5% hyperbaric bupivacaine and 0.5 mL of normal saline via a 5.0 mL syringe. Group B (n = 40) received 3.0 mL (15 mg) of 0.5% hyperbaric bupivacaine and 0.5 mL (25 µg) of fentanyl premixed via a single 5.0 mL syringe. Group C (n = 40) received 0.5 mL (25 µg) of fentanyl via a 1.0 mL syringe followed by 3.0 mL (15 mg) of 0.5% hyperbaric bupivacaine via a 5.0 mL syringe. Group D (n = 40) received 3.0 mL (15 mg) of 0.5% hyperbaric bupivacaine via a 5.0 mL syringe followed by 0.5 mL (25 µg) of fentanyl via a 1.0 mL syringe. The onset and regression of sensory and motor blockade, hemodynamic parameters, time to first rescue analgesia, and adverse events were observed. Data analysis was done using SPSS version 17.0 (SPSS Statistics Inc., Chicago, IL, USA). Results The mean time taken for the onset of sensory and motor blockade was least in Group D followed by Group C. Duration of sensory and motor blockade was prolonged in Group D. Patients in Group A experienced more hypotension than Groups B, C, and D. Requirement of rescue analgesia was delayed in Groups C and D. Conclusions Administering 25 µg (0.5 mL) of Fentanyl separately after 15 mg (3.0 mL) of 0.5% hyperbaric bupivacaine results in early onset and prolonged duration of sensory and motor blockade, intraoperative hemodynamic stability, the delayed requirement of rescue analgesia postoperatively, and fewer side effects compared to its co-administration as a premixed solution or antecedent to hyperbaric bupivacaine.

Perioperative Analgesia and Patients' Satisfaction in Spinal Anesthesia for Cesarean Section: Fentanyl Versus Morphine

Perioperative analgesia for cesarean section aims to ensure the mother's comfort, facilitate a smooth surgical experience, and promote a successful recovery. One-hundred-ninety patients were enrolled in a randomized double-blind study designed to assess the quality of perioperative analgesia, level of satisfaction, and incidence of adverse reactions in elective cesarean section under spinal anesthesia when fentanyl or morphine was added to bupivacaine. Two treatment groups comprising 173 subjects were compared in the per-protocol analysis: F (fentanyl, standard dose 25 μg) and M (morphine, standard dose 100 μg). Numerical pain scores were recorded perioperatively for 72 h (both at rest and on mobilization), with overall postoperative satisfaction and analgesic-related side effects. The patients in the morphine group had significantly better pain management (Mann-Whitney U test, p < 0.001) and higher level of satisfaction (Mann-Whitney U test, p < 0.001). The latter was related to the greater need for rescue medication in the fentanyl group (OR = 4.396; p = 0.019). On the other hand, fentanyl had significantly fewer non-life-threatening side effects, such as high-intensity pruritus (Mann-Whitney U test, p < 0.001), nausea (OR = 0.324; p = 0.019), vomiting and dizziness upon first mobilization (OR = 0.256; p < 0.001). It remains for future clinical trials to help establish doses that will tilt the scale to one side or the other.

Safety and effectiveness of adding fentanyl or sufentanil to spinal anesthesia: systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Spinal infusions of either fentanyl or sufentanil have been reported in international reports, articles, and scientific events worldwide. This study aimed to determine whether intrathecal fentanyl or sufentanil offers safety in mortality and perioperative adverse events.

METHODS

MEDLINE (via PubMed), EMBASE, CENTRAL (Cochrane library databases), gray literature, hand-searching, and clinicaltrials.gov were systematically searched. Randomized controlled trials with no language, data, or status restrictions were included, comparing the effectiveness and safety of adding spinal lipophilic opioid to local anesthetics (LAs). Data were pooled using the random-effects models or fixed-effect models based on heterogeneity.

RESULTS

The initial search retrieved 4469 records; 3241 records were eligible, and 3152 articles were excluded after reading titles and abstracts, with a high agreement rate (98.6%). After reading the full texts, 76 articles remained. Spinal fentanyl and sufentanil significantly reduced postoperative pain and opioid consumption, increased analgesia and pruritus. Fentanyl, but not sufentanil, significantly reduced both postoperative nausea and vomiting, and postoperative shivering; compared to LAs alone. The analyzed studies did not report any case of in-hospital mortality related to spinal lipophilic opioids. The rate of respiratory depression was 0.7% and 0.8% when spinal fentanyl or sufentanil was added and when it was not, respectively. Episodes of respiratory depression were rare, uneventful, occurred intraoperatively, and were easily manageable.

CONCLUSION

There is moderate to high quality certainty that there is evidence regarding the safety and effectiveness of adding lipophilic opioids to LAs in spinal anesthesia.

Accuracy of Spinal Anesthesia Drug Concentrations in Mixtures Prepared by Anesthetists

OBJECTIVE

Medication errors include the indirect dosing of drugs. For spinal anesthesia mixtures of local anesthetics, opioids are drawn from ampoules and combined in a syringe, according to clinical practice. We set out to determine the accuracy of the drug mixtures.

METHODS

Physicians of our department were invited to prepare the mixture used for spinal anesthesia for cesarean section, consisting of 10-mg hyperbaric bupivacaine (2-mL volume), 20-μg fentanyl (0.4-mL volume), and 100-μg morphine (0.1-mL volume). Concentrations of these drugs were determined by means of high performance liquid chromatography. Interindividual and intraindividual variations were assessed.

RESULTS

We analyzed 96 samples from 31 physicians. Fifty-one percent of the measured bupivacaine concentrations were in ±10% deviation range of the intended concentration; 17% of the fentanyl and 24% of the morphine concentrations were in this range. A total of 2.1% of the samples had a bupivacaine concentration corresponding to a dose of 8 mg or less, and 11.5% of the samples had a morphine concentration corresponding to a dose of 150 μg or greater. Intraindividual variations were 10.9% for bupivacaine, 24.7% for fentanyl, and 38.9% for morphine.

CONCLUSIONS

Our results show a high deviation of the obtained from the intended concentrations. Two percent of the samples had bupivacaine concentrations that probably resulted into an insufficient analgesia, and 11% of the samples had morphine concentrations that, according to guidelines, would require a longer monitoring period than with the intended dose.

Epidural administration of 2% Mepivacaine after spinal anesthesia does not prevent intraoperative nausea and vomiting during cesarean section: A prospective, double-blinded, randomized controlled trial

BACKGROUND

Intraoperative nausea and vomiting (IONV) is a common symptom during cesarean section (CS) delivery causing significant discomfort to patients. Combined spinal and epidural anesthesia (CSEA) can provide both intraoperative anesthesia and postoperative analgesia. During CSEA, it is reasonable to administer local anesthetics to the epidural space before patient complaints to compensate for the diminished effect of spinal anesthesia. Therefore, we hypothesized that intraoperative epidural administration of 2% mepivacaine would reduce the incidence of IONV.

METHODS

Patients who were scheduled for elective CS were randomly allocated to 2 groups. Patients and all clinical staff except for an attending anesthesiologist were blinded to the allocation. After the epidural catheter was inserted at the T11-12 or T12-L1 interspace, spinal anesthesia was performed at the L2-3 or L3-4 interspace to intrathecally administer 10 mg of 0.5% hyperbaric bupivacaine. Twenty min after spinal anesthesia, either 5 mL of 2% mepivacaine (group M) or saline (group S) was administered through an epidural catheter. Vasopressors were administered prophylactically to keep both the systolic blood pressure ≥ 80 % of the baseline value with the absolute value ≥ 90 mm Hg and the mean blood pressure ≥ 60 mm Hg. The primary endpoint was the incidence of IONV. The secondary endpoints were degree of nausea, the degree and incidence of pain, and Bromage score.

RESULTS

Ninety patients were randomized, and 3 patients were excluded from the final analysis. There was no significant difference in the incidence of IONV between the groups (58% in group M and 61% in group S, respectively, P = .82). In contrast, the incidence and degree of intraoperative pain in group M were significantly lower compared to group S. In addition, the incidence of rescue epidural administration of fentanyl (18% vs 47%) or mepivacaine (2.3% vs 25%) for intraoperative pain was lower in group M compared to group S.

CONCLUSIONS

Our results indicate that epidural administration of 2% mepivacaine 20 minutes after spinal anesthesia does not reduce the incidence of IONV in CS under CSEA. However, intraoperative epidural administration of 2% mepivacaine was found to improve intraoperative pain.

Spinal anesthesia for elective cesarean section. Bupivacaine associated with different doses of fentanyl: randomized clinical trial

OBJECTIVE

Assess patients submitted to elective cesarean section under spinal anesthesia, and the efficacy of different doses of fentanyl associated with bupivacaine.

METHODS

The study included 124 pregnant women randomly distributed into 4 groups (n = 31) according to different doses of fentanyl (15 μg, 10 μg, 7.5 μg), Groups I, II, and III, respectively, and control group IV, associated with 0.5% hyperbaric bupivacaine (10 mg). An epidural catheter was inserted in case epidural top-up was required. We assessed the anesthetic blockage characteristics, negative maternal and neonatal outcomes, and maternal side effects. Statistical analysis was performed using Kruskal-Wallis, Fisher's exact and chi-square tests. The level of significance was 5% (p < 0.05).

RESULTS

The quality of analgesia, time for the first complaint of pain and motor block recovery time were significantly better for groups that received fentanyl in comparison to controls (p < 0.001). None of the groups had negative maternal-fetal outcomes. Nausea was significantly more frequent in patients in Groups II (10 µg) and III (7.5 µg) when compared to Groups I (15 µg) and IV (no fentanyl). Vomiting was more frequent in Group III than in Group I (p = 0.006). The incidence of pruritus was significantly higher in the groups receiving fentanyl (p = 0.012).

CONCLUSIONS

Among the solutions studied, the spinal anesthesia technique using 15 µg of fentanyl associated with 10 mg of hyperbaric bupivacaine provided satisfactory analgesia and very low incidence of adverse effects for patients submitted to cesarean section.

TRIAL REGISTRATION NUMBER

UTN U1111-1199-0285.

REBEC

RBR-5XWT6T.

Comparison of Intrathecal Fentanyl and Buprenorphine as an Adjuvant to 0.5% Hyperbaric Bupivacaine for Spinal Anesthesia

Purpose:

This study was designed to evaluate and compare three groups, that is, (1) normal saline 0.5 mL with 15 mg of 0.5% hyperbaric bupivacaine normal (BN), (2) intrathecal fentanyl 25 μg (0.5 mL) as an adjuvant to 15 mg of 0.5% hyperbaric bupivacaine fentanyl (BF), and (3), 150 μg buprenorphine with 15 mg of 0.5% hyperbaric bupivacaine buprenorphine (BB) with respect to the onset and duration of sensory and motor spinal block, level of anesthesia, effects on hemodynamic parameters, requirement of postoperative analgesia, and side effects in patients aged 16–60 years undergoing surgical and orthopedic procedures requiring spinal anesthesia.

Methods:

A prospective, observational study was performed at a single center with 90 consecutive patients enrolled as per the inclusion criteria. Patients were divided into three groups of 30 each based on drugs administered, BN, BF, and BB groups, and outcome measures were recorded. The three groups were compared with the analysis of variance test for the continuous variables, with P < 0.05 considered statistically significant.

Results:

The groups were similarly matched with respect to age. The earliest onset of sensory block was in the BF group (2.87 min), P < 0.05. Similarly, the mean time to achieve the highest sensory level was least in the BF group (9.63 min), P < 0.05. The onset of motor blockade was earliest in the BB group (7.65 min), P < 0.05. The mean time for two segment regression was maximum in the BB group (126.03 min), P < 0.05. The mean time for regression to L1 was the longest in the BB group (200.83 min), P < 0.05. Maximum duration of analgesia after spinal drug administration was the highest in the BB group (412.17 min), P < 0.05.

Conclusion:

The addition of both buprenorphine 150 μg and fentanyl 25 μg to 0.5% hyperbaric bupivacaine 15 mg enhances the quality and duration of sensory block for spinal anesthesia providing better postoperative analgesia, while decreasing the incidence of complications associated with each drug alone.

Effects of intrathecal opioids on cesarean section: a systematic review and Bayesian network meta-analysis of randomized controlled trials

PURPOSE

We aimed to compare the beneficial and harmful effects of opioids used as adjuncts to local anesthetics in patients undergoing cesarean section under spinal anesthesia.

METHODS

We searched electronic databases and ClinicalTrials.gov from their inception until March, 2021 without language restrictions. The primary outcome was the complete analgesia duration (Time to VAS > 0). Data were synthesized using the Bayesian random-effects model. Evidence confidence was evaluated using the Confidence In Network Meta-Analysis.

RESULTS

We identified 66 placebo-controlled randomized controlled trials (RCTs) comprising 4400 patients undergoing elective cesarean section. Compared with the placebo, intrathecal opioids (fentanyl, sufentanil, and morphine) significantly prolonged the analgesia duration by 96, 96, and 190 min, respectively (mean difference). Despite morphine ranking first, opioid efficacy was similar; the results were inconsistent with respect to other analgesic outcomes. Except for diamorphine, all opioids were associated with significant increases in the pruritus incidence. Sufentanil and morphine were associated with increases in the respiratory depression incidence.

CONCLUSIONS

We confirmed that intrathecal opioids benefit postoperative analgesia. Although morphine seems to be the most appropriate agent, some results were inconsistent, and the evidence confidence was often moderate or low, especially for adverse outcomes. Well-designed RCTs with an evidence-based approach are imperative for determining the most appropriate opioid for cesarean sections.

Interventions for preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section

BACKGROUND

Nausea and vomiting are distressing symptoms which are experienced commonly during caesarean section under regional anaesthesia and in the postoperative period.  OBJECTIVES: To assess the efficacy of pharmacological and non-pharmacological interventions versus placebo or no intervention given prophylactically to prevent nausea and vomiting in women undergoing regional anaesthesia for caesarean section.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (16 April 2020), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of studies and conference abstracts, and excluded quasi-RCTs and cross-over studies.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Our primary outcomes are intraoperative and postoperative nausea and vomiting. Data entry was checked. Two review authors independently assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

Eighty-four studies (involving 10,990 women) met our inclusion criteria. Sixty-nine studies, involving 8928 women, contributed data. Most studies involved women undergoing elective caesarean section. Many studies were small with unclear risk of bias and sometimes few events. The overall certainty of the evidence assessed using GRADE was moderate to very low. 5-HT3 antagonists: We found intraoperative nausea may be reduced by 5-HT3 antagonists (average risk ratio (aRR) 0.55, 95% confidence interval (CI) 0.42 to 0.71, 12 studies, 1419 women, low-certainty evidence). There may be a reduction in intraoperative vomiting but the evidence is very uncertain (aRR 0.46, 95% CI 0.29 to 0.73, 11 studies, 1414 women, very low-certainty evidence). There is probably a reduction in postoperative nausea (aRR 0.40, 95% CI 0.30 to 0.54, 10 studies, 1340 women, moderate-certainty evidence), and these drugs may show a reduction in postoperative vomiting (aRR 0.47, 95% CI 0.31 to 0.69, 10 studies, 1450 women, low-certainty evidence). Dopamine antagonists: We found dopamine antagonists may reduce intraoperative nausea but the evidence is very uncertain (aRR 0.38, 95% CI 0.27 to 0.52, 15 studies, 1180 women, very low-certainty evidence). Dopamine antagonists may reduce intraoperative vomiting (aRR 0.41, 95% CI 0.28 to 0.60, 12 studies, 942 women, low-certainty evidence) and postoperative nausea (aRR 0.61, 95% CI 0.48 to 0.79, 7 studies, 601 women, low-certainty evidence). We are uncertain if dopamine antagonists reduce postoperative vomiting (aRR 0.63, 95% CI 0.44 to 0.92, 9 studies, 860 women, very low-certainty evidence). Corticosteroids (steroids): We are uncertain if intraoperative nausea is reduced by corticosteroids (aRR 0.56, 95% CI 0.37 to 0.83, 6 studies, 609 women, very low-certainty evidence) similarly for intraoperative vomiting (aRR 0.52, 95% CI 0.31 to 0.87, 6 studies, 609 women, very low-certainty evidence). Corticosteroids probably reduce postoperative nausea (aRR 0.59, 95% CI 0.49 to 0.73, 6 studies, 733 women, moderate-certainty evidence), and may reduce postoperative vomiting (aRR 0.68, 95% CI 0.49 to 0.95, 7 studies, 793 women, low-certainty evidence). Antihistamines: Antihistamines may have little to no effect on intraoperative nausea (RR 0.99, 95% CI 0.47 to 2.11, 1 study, 149 women, very low-certainty evidence) or intraoperative vomiting (no events in the one study of 149 women). Antihistamines may reduce postoperative nausea (aRR 0.44, 95% CI 0.30 to 0.64, 4 studies, 514 women, low-certainty evidence), however, we are uncertain whether antihistamines reduce postoperative vomiting (average RR 0.48, 95% CI 0.29 to 0.81, 3 studies, 333 women, very low-certainty evidence). Anticholinergics: Anticholinergics may reduce intraoperative nausea (aRR 0.67, 95% CI 0.51 to 0.87, 4 studies, 453 women, low-certainty evidence) but may have little to no effect on intraoperative vomiting (aRR 0.79, 95% CI 0.40 to 1.54, 4 studies; 453 women, very low-certainty evidence). No studies looked at anticholinergics in postoperative nausea, but they may reduce postoperative vomiting (aRR 0.55, 95% CI 0.41 to 0.74, 1 study, 161 women, low-certainty evidence). Sedatives: We found that sedatives probably reduce intraoperative nausea (aRR 0.65, 95% CI 0.51 to 0.82, 8 studies, 593 women, moderate-certainty evidence) and intraoperative vomiting (aRR 0.35, 95% CI 0.24 to 0.52, 8 studies, 593 women, moderate-certainty evidence). However, we are uncertain whether sedatives reduce postoperative nausea (aRR 0.25, 95% CI 0.09 to 0.71, 2 studies, 145 women, very low-certainty evidence) and they may reduce postoperative vomiting (aRR 0.09, 95% CI 0.03 to 0.28, 2 studies, 145 women, low-certainty evidence). Opioid antagonists: There were no studies assessing intraoperative nausea or vomiting. Opioid antagonists may result in little or no difference to the number of women having postoperative nausea (aRR 0.75, 95% CI 0.39 to 1.45, 1 study, 120 women, low-certainty evidence) or postoperative vomiting (aRR 1.25, 95% CI 0.35 to 4.43, 1 study, 120 women, low-certainty evidence). Acupressure: It is uncertain whether acupressure/acupuncture reduces intraoperative nausea (aRR 0.55, 95% CI 0.41 to 0.74, 9 studies, 1221 women, very low-certainty evidence). Acupressure may reduce intraoperative vomiting (aRR 0.52, 95% CI 0.33 to 0.80, 9 studies, 1221 women, low-certainty evidence) but it is uncertain whether it reduces postoperative nausea (aRR 0.46, 95% CI 0.27 to 0.75, 7 studies, 1069 women, very low-certainty evidence) or postoperative vomiting (aRR 0.52, 95% CI 0.34 to 0.79, 7 studies, 1069 women, very low-certainty evidence). Ginger: It is uncertain whether ginger makes any difference to the number of women having intraoperative nausea (aRR 0.66, 95% CI 0.36 to 1.21, 2 studies, 331 women, very low-certainty evidence), intraoperative vomiting (aRR 0.62, 95% CI 0.38 to 1.00, 2 studies, 331 women, very low-certainty evidence), postoperative nausea (aRR 0.63, 95% CI 0.22 to 1.77, 1 study, 92 women, very low-certainty evidence) and postoperative vomiting (aRR 0.20, 95% CI 0.02 to 1.65, 1 study, 92 women, very low-certainty evidence). Few studies assessed our secondary outcomes including adverse effects or women's views.

AUTHORS' CONCLUSIONS

This review indicates that 5-HT3 antagonists, dopamine antagonists, corticosteroids, sedatives and acupressure probably or possibly have efficacy in reducing nausea and vomiting in women undergoing regional anaesthesia for caesarean section. However the certainty of evidence varied widely and was generally low. Future research is needed to assess side effects of treatment, women's views and to compare the efficacy of combinations of different medications.

Prospective Randomized Control Trial Comparing Effect of Dexamethasone Versus Fentanyl as Adjuvants to Intrathecal Bupivacaine for Orthopedic Surgery

Introduction Spinal anesthesia is the most consistent block for lower limb orthopedic surgeries. We conducted this randomized prospective study to evaluate comparative efficacy of intrathecal dexamethasone with fentanyl and normal saline as adjuvants to hyperbaric bupivacaine in spinal anesthesia administered to patients scheduled for lower limb orthopedic surgery. Materials and methods 105 patients scheduled for lower limb orthopedic surgeries under spinal anesthesia were included in this clinical trial. After randomization, patients received an intrathecal injection of hyperbaric bupivacaine (12.5 mg) with 4 mg of dexamethasone in group I, hyperbaric bupivacaine (12.5 mg) with 25 ug fentanyl with 0.5 ml of normal saline in group II and hyperbaric bupivacaine (12.5 mg) with normal saline (1 ml) in group III, so as to make volume of drug equal in all three groups. The observer evaluated the sensory and motor blocks and other parameters like time to self-void, stay in post-anesthesia care unit (PACU) and complications.  Results The total duration of sensory blockade was found to be 311.43, 197.86 and 115.29 minutes and motor blockade of 223.43, 163.86 and 83.0 minutes in groups I, II and III respectively. The PACU stay was 233.14, 173.86 and 93.00 minutes in groups I, II and III, respectively. The average time to self-void was 400.00, 315.29 and 203.00 in three groups, respectively. Conclusion Intrathecal dexamethasone seemed to be an effective adjuvant to spinal bupivacaine as it prolongs the duration of analgesia, stable hemodynamic profile with minimal side effects. Further studies are required to evaluate the optimum dose and long-term safety of intrathecal dexamethasone.

Effect of intrathecal lipophilic opioids on the incidence of shivering in women undergoing cesarean delivery after spinal anesthesia: a systematic review and bayesian network meta- analysis of randomized controlled trials

Background

Shivering is a common side effect in women having cesarean delivery (CD) under spinal anesthesia, which can be bothersome to the patient, and it can also interfere with perioperative monitoring. In several studies, the intrathecal (IT) addition of a lipophilic opioid to local anesthetics has been shown to decrease the incidence of shivering.

Objective

We performed this network meta-analysis to evaluate the effects of intrathecal lipophilic opioids in preventing the incidence of shivering in patients undergoing CD.

Methods

This review was planned according to the PRISMA for Network Meta-Analysis (PRISMA-NMA) guidelines. An English literature search of multiple electronic databases was conducted. We included randomized controlled trials (RCTs) that reported on the incidence of shivering, with study groups receiving either IT fentanyl, sufentanil, or meperidine in women undergoing CD under spinal anesthesia. Quality of the studies was assessed using the modified Oxford scoring system. Using random-effects modeling, dichotomous data were extracted and summarized using odds ratio (OR) with a 95% credible interval (CrI). Statistical analysis was conducted using R studio version 1.0.153 - Inc.

Results

Twenty-one studies consisting of 1433 patients (Control group: 590 patients in twenty-one studies; Fentanyl group:199 patients in seven studies; Sufentanil group: 156 patients in five studies; Meperidine group: 488 patients in ten studies) met the inclusion criteria for this systematic review investigating the effect of intrathecal lipophilic opioids in preventing the incidence of shivering in women undergoing cesarean delivery under spinal anesthesia. Methodological validity scores ranged from 3 to 7. The Bayesian mixed network estimate showed the incidence of shivering was significantly lower with IT fentanyl (pooled odds ratio (OR): 0.13; 95% credible interval (CrI): 0.04 to 0.35; P = 0.0004) and IT meperidine (OR: 0.12; 95% CrI: 0.05 to 0.29; P < 0.00001), but not with IT sufentanil (OR: 0.37; 95% CrI: 0.11 to 1.22; P = 0.23). The IT fentanyl group had a significantly lower incidence of intraoperative discomfort [Risk Ratio (RR): 0.19; 95% CI: 0.10–0.35; P < 0.00001], the IT sufentanil group had a significantly higher incidence of pruritus (RR: 6.18; 95% CI: 1.18–32.46; P = 0.03) The IT meperidine group had a significantly lower incidence of intraoperative discomfort (2.7% vs. 13.6%; RR: 0.22; 95% CI: 0.09–0.55; P = 0.001), but there was a significant increase in nausea and vomiting (IT meperidine group vs. Control group: 42.7% vs. 19.4%; RR: 2.56; 95% CI: 1.14–5.75; P = 0.02). Meta-regression analysis based on the opioid dose and quality of the study did not impact the final inference of our result.

Conclusion

IT fentanyl significantly decreased the incidence of shivering in women undergoing CD under spinal anesthesia without increasing maternal adverse events, confirming that routine use in this patient population is a good choice. IT sufentanil did not decrease the incidence of shivering. IT meperidine decreased the incidence and severity of shivering, but its use was also associated with significant nausea and vomiting.

Comparison of Epidural Bupivacaine and Dexmedetomidine with Bupivacaine and Fentanyl for Postoperative Pain Relief in Lower Limb Orthopedic Surgery

Context

Different trials have shown that multimodal analgesia through different techniques is associated with superior pain relief. Opioids as epidural adjunct to local anesthetics have been in use for long and α₂ agonists are being increasingly used for same. The present study aims at comparing the hemodynamic, sedative, and analgesic effects of epidurally administered fentanyl and dexmedetomidine when combined with bupivacaine.

Aims

The aim of this study was to compare the efficacy of epidural dexmedetomidine with bupivacaine versus epidural fentanyl with bupivacaine for postoperative pain relief.

Subjects and Methods

In this ongoing randomized double-blind study, 70 patients with ASA physical status classes I and II of either sex between 20 and 60 years scheduled for lower limb orthopedic surgeries under epidural block were randomly divided into two Groups (n = 35). After epidural block with 15 ml of 0.5% bupivacaine, Group I received 1 μg/kg of fentanyl and Group II received 1 μg/kg of dexmedetomidine. Onset and duration of sensory block, motor block, and time to request for the first postoperative analgesia were recorded.

Statistical Analysis Used

The statistical analysis was performed using SPSS (Statistical Package for the Social Sciences) Version 15.0 Statistical Analysis Software, Mann-Whitney U-test and Chi-square test.

Results

The time to achieve T₁₀ sensory block was early in Group I (dexmedetomidine) (8.10 + 1.03 min) as compared to Group II (15.03 + 1.67 min). Onset of motor was earlier in Group I (15.10 + 1.49 min) as compared to Group II (22.77 + 1.41 min). In Group I (dexmedetomidine), the majority of patients required 2-3 rescue doses, while in Group II (fentanyl), the majority of patients required 3-4 rescue doses.

Conclusions

Dexmedetomidine seems to be a better alternative to fentanyl as an epidural adjuvant due to early onset of sensory anesthesia, prolonged postoperative analgesia, and lower consumption of rescue analgesia.

Postoperative Analgesia with Intrathecal Nalbuphine versus Intrathecal Fentanyl in Cesarean Section: A Double-Blind Randomized Comparative Study

Background:

Nalbuphine when used as adjuvant to hyperbaric bupivacaine has improved the quality of perioperative analgesia with fewer side effects. Fentanyl is a lipophilic opioid with a rapid onset following intrathecal injection. It does not cause respiratory depression and improves duration of sensory anesthesia without producing significant side effects.

Aim:

This study aims to compare the postoperative analgesia of intrathecal nalbuphine and fentanyl as adjuvants to bupivacaine in cesarean section.

Methodology:

A prospective, randomized, double-blind, and comparative study was conducted on 150 parturients of American Society of Anesthesiologists (ASA) physical status I and II of age group 20–45 years with normal coagulation profile undergoing cesarean section under spinal anesthesia. These patients were randomized into three groups with fifty patients in each group. Group I received 2 ml of 0.5% hyperbaric bupivacaine (10 mg) plus 0.4 ml nalbuphine (0.8 mg), Group II received 2 ml of 0.5% hyperbaric bupivacaine (10 mg) plus 0.4 ml fentanyl (20 μg), and Group III received 2 ml of 0.5% hyperbaric bupivacaine (10 mg) plus 0.4 ml of normal saline.

Results:

The mean duration of effective analgesia was 259.20 ± 23.23 min in Group I, 232.70 ± 13.15 min in Group II, and 168.28 ± 7.55 min in Group III. The mean number of rescue analgesics required was significantly lower (P < 0.001) in Group I as compared to Group II and III.

Conclusion:

Both intrathecal nalbuphine 0.8 mg and fentanyl 20 μg are effective adjuvants to 0.5% hyperbaric bupivacaine in subarachnoid block. However, intrathecal nalbuphine prolongs postoperative analgesia maximally and may be used as an alternative to intrathecal fentanyl in cesarean section.

Perioperative analgesia after intrathecal fentanyl and morphine or morphine alone for cesarean section: A randomized controlled study

OBJECTIVES

Intrathecal morphine is used in the postoperative management of pain after caesarean section (CS), but might not be optimal for intraoperative analgesia. We hypothesized that intrathecal fentanyl could supplement intraoperative analgesia when added to a local anesthetic and morphine without affecting management of postoperative pain.

METHODS

This prospective, randomized, double-blind, parallel-group study included 60 parturients scheduled for elective CS. Spinal anesthesia consisted of bupivacaine with either morphine 100 μg (M group), or fentanyl 25 μg and morphine 100 μg (FM group). The frequency of intraoperative pain and pethidine consumption in the 24 hours postoperatively was recorded.

RESULTS

Fewer patients in the FM group required additional intraoperative analgesia (P < .01, relative risk 0.06, 95% confidence interval [CI] 0.004-1.04). The FM group was noninferior to the M group for 24-hour opioid consumption (95% CI -10.0 mg to 45.7 mg, which was below the prespecified boundary of 50 mg). Pethidine consumption in postoperative hours 1 to 12 was significantly higher in the FM group (P = .02). Postoperative nausea and vomiting (PONV) were more common in the FM group (P = .01). Visual analog scale scores, effective analgesia, Apgar scores, and rates of pruritus and respiratory depression were similar between the groups.

CONCLUSIONS

Intrathecal combination of fentanyl and morphine may provide better perioperative analgesia than morphine alone in CS and could be useful when the time from anesthesia to skin incision is short. However, an increase in PONV and possible acute spinal opioid tolerance after addition of intrathecal fentanyl warrants further investigation using lower doses of fentanyl.

Comparing the Effect of Adding Fentanyl, Sufentanil, and Placebo with Intrathecal Bupivacaine on Duration of Analgesia and Complications of Spinal Anesthesia in Patients Undergoing Cesarean Section

Background

Spinal anesthesia is the method of choice for most elective and emergency Cesarean sections. To increase the duration of anesthesia and improve the quality of analgesia during and after surgery, intrathecal opioids, as adjuvant drugs, are used in combination with local anesthetics.

Methods

This was a double-blind clinical trial performed on 99 patients. Women were divided into 3 groups of fentanyl, sufentanil, and placebo. For fentanyl group, 12.5 mg of bupivacaine and 25 micrograms of fentanyl; for sufentanil group, 12.5 mg of bupivacaine and 2.5 micrograms of sufentanil; and for placebo group, 12.5 mg of bupivacaine and a half mL of normal saline were injected in subarachnoid space. The sensory and motor block, hemodynamic status (mean blood pressure and heart rate), and probable complications were assessed.

Results

There was no significant difference between the groups in demographic characteristics. Durations of analgesia were, respectively, 314 ± 42.95, 312.5 ± 34.44, and 116.1 ± 42.24 minutes in the fentanyl, sufentanil, and placebo groups (P = 0.0001). Duration of sensory and motor block was higher in fentanyl and sufentanil groups compared with the placebo group. The highest duration of sensory and motor block was noted in sufentanil group (P = 0.0001). No significant difference was found between the groups in the hemodynamic parameters (P > 0.05). The frequency of itching in the fentanyl group was higher than sufentanil and placebo groups (P = 0.003). Also, shivering was higher in the placebo group compared with other groups (P = 0.036).

Conclusions

According to the results, adding 25 microgram fentanyl or 2.5 microgram sufentanil to intrathecal bupivacaine increased the duration of analgesia and provided hemodynamic stability with no major complication. As administering intrathecal fentanyl had a similar duration of analgesia like sufentanil with faster return of motor block and ambulation, it seems that it is a preferred additive for Cesarean section surgery.

Comparison of intrathecal clonidine and fentanyl in hyperbaric bupivacaine for spinal anesthesia and postoperative analgesia in patients undergoing lower abdominal surgeries

BACKGROUND

There are many adjuvant used along with bupivacaine for subarachnoid block, but fentanyl and clonidine are commonly used as adjuvant to intrathecal bupivacaine for prolonging both sensory and motor blockade as well as postoperative analgesia in patients undergoing lower abdominal surgeries.

OBJECTIVE

There is a paucity of studies comparing the efficacy of fentanyl and clonidine as adjuvant to intrathecal bupivacaine for improving intraoperative effect and postoperative analgesia in lower abdominal surgeries instigated us compare the effect of these drugs.

METHODS

This prospective, randomized study is conducted on 100 American Society of Anesthesiologists I or II patients between 18 and 65 years of age divided into two groups of 50 each. The patients were given 2.5 ml of 0.5% hyperbaric bupivacaine with either 50 μg of clonidine (BC Group) or 25 μg of fentanyl (BF Group) intrathecally. The onset and duration of sensory and motor block, sedation score, hemodynamic parameters, total analgesia time, and potential side effects were recorded and compared.

RESULTS

Both the groups were comparable in demographic data, onset and duration of sensory and motor blockade, hemodynamic parameters, but the duration of analgesia is significantly longer in clonidine group when compared with fentanyl group. Sedation score is more in clonidine group.

CONCLUSION

Addition of clonidine to intrathecal bupivacaine offers longer duration of postoperative analgesia than fentanyl but with higher sedation.

Analgesic Efficacy of Transverse Abdominal Plane Block after Elective Cesarean Delivery - Bupivacaine with Fentanyl versus Bupivacaine Alone: A Randomized, Double-blind Controlled Clinical Trial

Background:

The analgesic benefit of transversus abdominis plane (TAP) blocks for cesarean delivery remains controversial. In our study, we compared the analgesic efficacy of TAP block using local anesthetic bupivacaine and adjunct fentanyl with bupivacaine alone in patients undergoing elective cesarean section.

Methods:

Our study was a randomized, double-blind, controlled clinical trial where sixty patients undergoing elective cesarean delivery under subarachanoid block (2 ml of 0.5% bupivacaine) were randomized into two groups, A and B. At the end of the surgical procedure, bilateral TAP block was performed guided by the ultrasound. Group A received 38 ml of 0.25% bupivacaine and 2 ml of 50 μg of fentanyl, whereas Group B received 38 ml of 0.25% bupivacaine + 2 ml of normal saline. The total volume was divided equally and administered bilaterally. Each patient was assessed for 24 h after TAP block, for time to rescue analgesia, pain using visual analog scale (VAS) score at rest and on movement, hemodynamic parameters (heart rate and blood pressure), nausea, vomiting, and sedation. Diclofenac 75 mg was given as rescue analgesia when the patient complained of pain or when VAS score >4.

Results:

Prolonged postoperative analgesia was noticed with both the groups, with a mean time to rescue analgesia of approximately 6.5 h. There was no significant difference in time to rescue analgesia (6.49 ± 0.477 vs. 6.5 ± 0.480) when both the groups were compared among themselves. The pain scores among the two groups when compared did not show any added benefit. Incidence of nausea, vomiting, and sedation when compared between both the groups showed no difference.

Conclusion:

The TAP block as a part of a multimodal analgesic regimen definitely has a role in providing superior analgesia in the postoperative period. However, adjunct fentanyl to local anesthetic bupivacaine was found to have no added advantage when quality and duration of analgesia was compared.

Relation between fentanyl dose and patient state index during spinal anesthesia for elective cesarean section

Background

In spinal anesthesia for cesarean section, the addition of fentanyl to the local anesthetic has been reported to improve perioperative analgesia. However, there is only limited knowledge on sedative effects of the added fentanyl. We examined whether the patient state index® (PSI) can detect and present the light sedated level with patients undergoing cesarean section.

Findings

We measured respiratory rate (RR), SpO2, and PSI values. Between child delivery and the completion of the operation, the proportions of time with the PSI values <90 and 80 were calculated. RR <8 breaths/min or SpO2 <95 % was defined as respiratory depression. Respiratory depression was not observed in any patient. At fentanyl doses of 10, 15, and 20 μg, the proportions of time with the PSI <90 were 14.5 ± 20.8, 49.4 ± 35.3, and 71.1 ± 22.9 %, respectively (P < 0.01). There were significant differences between 10 and 15 μg (P < 0.05), and 10 and 20 μg (P < 0.01). Similarly, the proportions of time with the PSI values <80 were 0.5 ± 1.8, 21.1 ± 24.1, and 31.8 ± 32.2 %, respectively (P < 0.05). There was a significant difference between 10 and 20 μg (P < 0.05).

Conclusions

The PSI values decreased in a dose-dependent manner with increasing dose of fentanyl, but no respiratory depression was observed. The PSI values decreased to less than 90, when fentanyl was administered more than 15 μg. Furthermore, the PSI values decreased to less than 80, when fentanyl was administered 20 μg.

Analgesic efficacy of intrathecal fentanyl during the period of highest analgesic demand after cesarean section: A randomized controlled study

Cesarean section (CS) is one of the most common surgical procedures in female patients. We aimed to evaluate the postoperative analgesic efficacy of intrathecal fentanyl during the period of greatest postoperative analgesic demand after CS. This period was defined by detailed analysis of patient-controlled analgesia (PCA) usage.This double-blind, placebo-controlled, parallel-group randomized trial included 60 parturients who were scheduled for elective CS. Participants received spinal anesthesia with bupivacaine supplemented with normal saline (control group) or with fentanyl 25 μg (fentanyl group). To evaluate primary endpoints, we measured total pethidine consumption over the period of greatest PCA pethidine requirement. For verification of secondary endpoints, we recorded intravenous PCA requirement in other time windows, duration of effective analgesia, pain scores assessed by visual analog scale, opioid side effects, hemodynamic changes, neonatal Apgar scores, and intraoperative pain.Detailed analysis of hour-by-hour PCA opioid requirements showed that the greatest demand for analgesics among patients in the control group occurred during the first 12 hours after surgery. Patients in the fentanyl group had significantly reduced opioid consumption compared with the controls during this period and had a prolonged duration of effective analgesia. The groups were similar in visual analog scale, incidence of analgesia-related side effects (nausea/vomiting, pruritus, oversedation, and respiratory depression), and neonatal Apgar scores. Mild respiratory depression occurred in 1 patient in each group. Fewer patients experienced intraoperative pain in the fentanyl group (3% vs 23%; relative risk 6.8, 95% confidence interval 0.9-51.6).The requirement for postoperative analgesics is greatest during the first 12 hours after induction of anesthesia in patients undergoing CS. The addition of intrathecal fentanyl to spinal anesthesia is effective for intraoperative analgesia and decreases opioid consumption during the period of the highest analgesic demand after CS, without an increase in maternal or neonatal side effects. We recommend using intrathecal fentanyl for CS in medical centers not using morphine or other opioids intrathecally at present.

Sufentanil and Bupivacaine Combination versus Bupivacaine Alone for Spinal Anesthesia during Cesarean Delivery: A Meta-Analysis of Randomized Trials

Objective

The addition of lipophilic opioids to local anesthetics for spinal anesthesia has become a widely used strategy for cesarean anesthesia. A meta-analysis to quantify the benefits and risks of combining sufentanil with bupivacaine for patients undergoing cesarean delivery was conducted.

Methods

A comprehensive literature search without language or date limitation was performed to identify clinical trials that compared the addition of sufentanil to bupivacaine with bupivacaine alone for spinal anesthesia in healthy parturients choosing cesarean delivery. The Q and I² tests were used to assess heterogeneity of the data. Data from each trial were combined using relative ratios (RRs) for dichotomous data or weighted mean differences (WMDs) for continuous data and corresponding 95% confidence intervals (95% CIs) for each trial. Sensitivity analysis was conducted by removing one study a time to assess the quality and consistency of the results. Begg’s funnel plots and Egger’s linear regression test were used to detect any publication bias.

Results

This study included 9 trials containing 578 patients in the final meta-analysis. Sufentanil addition provided a better analgesia quality with less breakthrough pain during surgery than bupivacaine alone (RR = 0.10, 95% CI 0.06 to 0.18, P < 0.001). Sensory block onset time was shorter and first analgesic request time was longer in sufentanil added group compared with the bupivacaine-alone group (WMD = −1.0 min, 95% CI −1.5 to −0.58, P < 0.001 and WMD = 133 min, 95% CI 75 to 213, P < 192, respectively). There was no significant difference in the risk of hypotension and vomiting between these two groups. But pruritus was more frequentely reported in the group with sufentanil added (RR = 7.63, 95% CI 3.85 to 15.12, P < 0.001).

Conclusion

Bupivacaine and sufentanil combination is superior to that of bupivacaine alone for spinal anesthesia for cesarean delivery in analgesia quality. Women receiving the combined two drugs had less breakthrough pain, shorter sensory block onset time, and longer first analgesic request time. However, the addition of sufentanil to bupivacaine increased the incidence of pruritus.

A randomized controlled study between fentanyl and Butorphanol with low dose intrathecal bupivacaine to facilitate early postoperative ambulation in urological procedures

Introduction:

Opioids are widely used in conjunction with local anesthetics as they permit the use of lower dose of local anesthetics while providing adequate anesthesia and analgesia. It both provides adequate anesthesia as well as lower drug toxicity neuraxial administration of opioids in conjunction with local anesthetics improves the quality of intraoperative analgesia and prolongs the duration of postoperative analgesia. Bupivacaine is the most commonly used drug for subarachnoid block due to its lesser side effects. The present study was conducted to decrease the overall dose of local anesthetics with opioid combination for urological procedure with respect to quality of anesthesia and recovery with patient's satisfaction.

Materials and Methods:

The study population was randomly allocated by computer generated table into two groups; Group A: 5 mg 0.5% bupivacaine + 25 mcg and Group B: 5 mg 0.5% bupivacaine + 25 mg butorphanol.

Results:

Highest level of sensory block was T9 and T8 with the fentanyl group and butorphanol group, respectively. The onset of sensory block was early in fentanyl group than butorphanol group. Duration of both sensory and motor block was significantly higher in butorphanol group. There was no incidence of itching in both groups. There were two patients in fentanyl group and one in butorphanol with hypotension for which injection mephentermine was given. Two patients in fentanyl group complained of nausea and vomiting, for which injection ondansetron was given. One patient complained of pain in fentanyl group for which injection propofol with injection fentanyl was supplemented.

Conclusion:

Low-dose bupivacaine with butorphanol group was devoid of any side effects in the present study but low dose bupivacaine in addition with fentanyl is superior in terms of early postoperative recovery resulting in early discharge and better outcome in comparison to bupivacaine and butorphanol group, which is beneficial in elderly patients with comorbidity.

Efficacy of lipophilic vs lipophobic opioids in addition to hyperbaric bupivacaine for patients undergoing lower segment caeserean section

BACKGROUND

Subarachnoid block is the preferred technique for providing anesthesia for patients undergoing cesarean section. Various pharmacological agents in added to local anesthetics (LA) modify their original effects in terms of block characteristics and quality of analgesia. However, there is ongoing debate about this practice of using adjuncts with LA. We tested whether addition of lipophilic versus lipophobic opioids to LA gives any clinical benefits to maternal and fetal outcome when used in these patients requiring spinal anesthesia.

SUBJECTS AND METHODS

Sixty American Society of Anesthesiologists I and II parturients, undergoing elective cesarean section requiring subarachnoid block, were included in our study. The parturients were allocated randomly to three groups of 20 each to receive bupivacaine 12.5 mg (Group I), bupivacaine 12.5 mg + morphine 0.2 mg (Group II), bupivacaine 12.5 mg + fentanyl 25 μg (Group III), preservative free physiological saline 0.9% was added to all the solutions to achieve a total volume of 4 ml. The parameters studied were the time of onset, sensory level of the block achieved, total duration of analgesia, any need of rescue analgesics, maternal side effects, and fetal outcome.

RESULTS

Onset of block was early 4.30 ± 0.12 min in Group III as compared to Group I 4.64 ± 0.28 min and Group II 4.505 ± 0.22 min. Mean duration of analgesia (hours) was higher in Group II 15.91 ± 0.96 h as compared to Group I 1.95 ± 0.55 h and Group III 4.39 ± 0.2 h. Incidence of nausea, vomiting, and shivering was more in the control group as compared to study groups, whereas sedation and pruritus were seen more in the study groups. No adverse effects on fetus were seen with use of opioids and comparable Apgar scores were noted.

CONCLUSION

Addition of intrthecal fentanyl causes rapid onset of block whereas intrathecal morphine provides prolonged analgesia with comparable neonatal wellbeing.

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

Introduction:

The intrathecal administration of combination of drugs has a synergistic effect on the subarachnoid block characteristics. This study was designed to study the efficacy of intrathecal midazolam in potentiating the analgesic duration of fentanyl along with prolonged sensorimotor blockade.

Materials and Methods:

In a double-blind study design, 75 adult patients were randomly divided into three groups: Group B, 3 ml of 0.5% hyperbaric bupivacaine; Group BF, 3 ml of 0.5% hyperbaric bupivacaine + 25 mcg of fentanyl; and Group BFM, 3 ml of 0.5% hyperbaric bupivacaine + 25 mcg of fentanyl + 1 mg of midazolam. Postoperative analgesia was assessed using visual analog scale scores and onset and duration of sensory and the motor blockade was recorded.

Results:

Mean duration of analgesia in Group B was 211.60 ± 16.12 min, in Group BF 420.80 ± 32.39 min and in Group BFM, it was 470.68 ± 37.51 min. There was statistically significant difference in duration of analgesia between Group B and BF (P = 0.000), between Group B and BFM (P = 0.000), and between Group BF and BFM (P = 0.000). Both the onset and duration of sensory and motor blockade was significantly prolonged in BFM group.

Conclusion:

Intrathecal midazolam potentiates the effect of intrathecal fentanyl in terms of prolonged duration of analgesia and prolonged motor and sensory block without any significant hemodynamic compromise.

Association of lipophilic opioids and hyperbaric bupivacaine in spinal anesthesia for elective cesarean section. Randomized controlled study

PURPOSE

To evaluate the efficacy and side-effects of fentanyl and sufentanil combined with hyperbaric spinal bupivacaine in elective cesarean section.

METHODS

A prospective, randomized, double-blind study with 64 term parturients, distributed into 2 groups according to the opioid combined with hyperbaric bupivacaine 0.5% (10mg): GF - fentanyl (25 µg) and GS - sufentanil (5.0 µg). The latency and maximum sensory block level; degree and duration of motor block; duration and quality of analgesia; maternal-fetal repercussions were evaluated. This was an intention-to-treat analysis with a 5% significance level.

RESULTS

The latency period, maximum sensory block level, motor block degree and perioperative analgesia were similar in both groups. Motor block and analgesia had a longer duration in the sufentanil group. Maternal adverse effects and neonatal repercussions were similar. The incidence of hypotension was higher in the fentanyl group. In both groups, there was a predominance of patients who were awake and either calm or sleepy.

CONCLUSIONS

The addition of fentanyl and sufentanil to hyperbaric subarachnoid bupivacaine was shown to be effective for the performance of cesarean section, and safe for the mother and fetus. Analgesia was more prolonged with sufentanil.

Intrathecal Meperidine versus intrathecal Fentanyl for prevention of shivering in lower limb orthopedic surgeries under spinal anesthesia: A randomized double-blind placebo-controlled trial

Objective:

Shivering is an unpleasant sensation for patients who undergoing spinal anesthesia. This randomized double-blind clinical trial study was designed to compare the effect of intrathecal fentanyl with intrathecal meperidine for prevention of shivering in lower limb orthopedic surgeries under spinal anesthesia.

Methods:

Ninety patients were randomly recruited to receive either 3 ml of 0.5% hyperbaric bupivacaine plus 20 μg of fentanyl (Group F), or 3 ml of 0.5% hyperbaric bupivacaine plus 0.2 mg/kg of meperidine (Group M), or 3 ml of 0.5% hyperbaric bupivacaine plus normal saline (Group S). The incidence and intensity of shivering were compared in three groups. Data were analyzed by analysis of variances, Mann–Whitney U-test followed by Chi-square test.

Findings:

There were not statistically differences in complications and side-effects between three groups. Total incidence of shivering was similar between Groups F and M (16.7% vs. 13.3% respectively, P = 0.72) whereas it was significantly different to Group S (43.3%) (P = 0.025 for Group F vs. S, and P = 0.011 for Group M vs. S). Also the intensity of shivering between Groups F and M was similar (P = 0.66), while it was significantly less in these groups compared to Group S (P = 0.013 and P = 0.004, respectively).

Conclusion:

Addition of fentanyl 20 μg or meperidine 0.2 mg/kg to 0.5% bupivacaine intrathecally significantly decreased the incidence of shivering in lower limb orthopedic surgeries. There was no significant difference between two drugs with this respect.

[Low-dose levobupivacaine plus fentanyl combination for spinal anesthesia in anorectal surgery]

BACKGROUND

The aim of this study was to investigate the effects of spinal anesthesia using two different doses of fentanyl combined with low-dose levobupivacaine in anorectal surgery.

METHODS

In this prospective, double-blind study, 52 American Society of Anaesthesiologists I-II patients scheduled for elective anorectal surgery were randomized into two groups. The patients in group I received intrathecal 2.5mg hyperbaric levobupivacaine plus 12.5μg fentanyl and in group II received intrathecal 2.5mg hyperbaric levobupivacaine plus 25μg fentanyl. All the patients remained in the seated position for 5min after completion of the spinal anesthesia. Sensory block was evaluated with pin-prick test and motor block was evaluated with a modified Bromage scale.

RESULTS

Motor block was not observed in both of the groups. The sensory block was limited to the S2 level in group I, and S1 level in group II. None of the patients required additional analgesics during the operation. Time to two-segment regression was shorter in group I compared with group II (p<0.01). One patient in group I and 5 patients in group II had pruritus. Hemodynamic parameters were stable during the operation in both of the groups.

CONCLUSION

Spinal saddle block using hyperbaric levobupivacaine with both 12.5μg and 25μg fentanyl provided good quality of anesthesia without motor block for anorectal surgery in the prone position.

Bupivacaine-sufentanil versus bupivacaine-fentanyl in spinal anesthesia of patients undergoing lower extremity surgery

BACKGROUND

The addition of intrathecal opioids to local anesthetics seems to improve the quality of analgesia and prolong the duration of analgesia, when using a subarachnoid block in Iranian patients with their specific pain tolerance.

OBJECTIVES

The aim of this study was to evaluate the effects of adding fentanyl or sufentanil, to intrathecal bupivacaine, in terms of the onset and duration of; sensory block, motor block, hemodynamic effects and postoperative pain relief.

PATIENTS AND METHODS

This randomized clinical trial included 90 patients who underwent orthopedic lower limb surgeries. Subjects were divided into experimental groups; intrathecal fentanyl 25 µg (F), and sufentanil 2.5 µg (S), along with a placebo 0.5 mL normal saline (C) group, which were added to bupivacaine 0.5%, 15 mg. Duration of complete and effective analgesia was recorded (by a visual analogue scale-VAS). The pain scores were assessed postoperatively. Intraoperative mean arterial pressure (MAP), heart rate and oxygen saturation (SPO(2)) were recorded. The incidence of side effects such as; nausea, vomiting, pruritus, shivering, bradycardia and hypotension were also recorded.

RESULTS

MAP and heart rate results showed no significant changes at the designated time points among the three groups (P > 0.05). However, SPO2 and VAS showed significant changes at the designated time points among the three groups (P < 0.05). The duration of complete and effective analgesia was also significantly longer in the sufentanil group (P < 0.05). Motor block did not exhibit any significant difference (P = 0.67). Only pruritus as a side effect was significantly higher in the sufentanil group (P < 0.05), while all other evaluated side effects were significantly lower in the sufentanil group (P < 0.05).

CONCLUSIONS

The addition of 2.5-3 mcg sufentanil to 15 mg 0.05% bupivacaine maintained the patient's hemodynamic stability similar to fentanyl. Intrathecal sufentanil added to bupivacaine,when compared with fentanyl, may lead to prolonged duration of analgesia, facilitate the spread of the sensory block, increase mean SPO2 levels, and reduce overall side effects.

Low-dose levobupivacaine plus fentanyl combination for spinal anesthesia in anorectal surgery

BACKGROUND

the aim of this study was to investigate the effects of spinal anesthesia using two different doses of fentanyl combined with low-dose levobupivacaine in anorectal surgery.

METHODS

in this prospective, double-blind study, 52 American Society of Anaesthesiologists I-II patients scheduled for elective anorectal surgery were randomized into two groups. The patients in group I received intrathecal 2.5mg hyperbaric levobupivacaine plus 12.5 μg fentanyl and in group II received intrathecal 2.5mg hyperbaric levobupivacaine plus 25 μg fentanyl. All the patients remained in the seated position for 5 min after completion of the spinal anesthesia. Sensory block was evaluated with pin-prick test and motor block was evaluated with a modified Bromage scale.

RESULTS

motor block was not observed in both of the groups. The sensory block was limited to the S2 level in group I, and S1 level in group II. None of the patients required additional analgesics during the operation. Time to two-segment regression was shorter in group I compared with group II (p<0.01). One patient in group I and 5 patients in group II had pruritus. Hemodynamic parameters were stable during the operation in both of the groups.

CONCLUSION

spinal saddle block using hyperbaric levobupivacaine with both 12.5 μg and 25 μg fentanyl provided good quality of anesthesia without motor block for anorectal surgery in the prone position.

Interventions at caesarean section for reducing the risk of aspiration pneumonitis

BACKGROUND

Aspiration pneumonitis is a syndrome resulting from the inhalation of gastric contents. The incidence in obstetric anaesthesia has fallen, largely due to improved anaesthetic techniques and the increased use of regional anaesthesia at caesarean section. However, aspiration pneumonitis is still a cause of maternal morbidity and mortality, and it is important to use effective prophylaxis.

OBJECTIVES

To determine whether interventions given prior to caesarean section reduce the risk of aspiration pneumonitis in women with an uncomplicated pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2013).

SELECTION CRITERIA

Randomised controlled trials were included. Quasi-randomised trials were excluded.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Data entry was checked. Fixed-effect meta-analysis was used to combine data where it was reasonable to assume that studies were estimating the same underlying treatment effect. If substantial clinical or statistical heterogeneity was detected, we used random-effects analysis to produce an overall summary.

MAIN RESULTS

Thirty-two studies were included in this review. However, only 22 studies, involving 2658 women, provided data for analysis. All the women in the included studies had a caesarean section under general anaesthesia. The studies covered a number of comparisons, but were mostly small and of unclear or poor quality.When compared with no treatment or placebo, there was a significant reduction in the risk of intragastric pH < 2.5 with antacids (risk ratio (RR) 0.17, 95% confidence interval (CI) 0.09 to 0.32, two studies, 108 women), H2 antagonists (RR 0.09, 95% CI 0.05 to 0.18, two studies, 170 women) and proton pump antagonists (RR 0.26, 95% CI 0.14 to 0.46, one study 80 women). H2 antagonists were associated with a reduced the risk of intragastric pH < 2.5 at intubation when compared with proton pump antagonists (RR 0.39, 95% CI 0.16 to 0.97, one study, 120 women), but compared with antacids the findings were unclear. The combined use of 'antacids plus H2 antagonists' was associated with a significant reduction in the risk of intragastric pH < 2.5 at intubation when compared with placebo (RR 0.02, 95% CI 0.00 to 0.15, one study, 89 women) or compared with antacids alone (RR 0.12, 95% CI 0.02 to 0.92, one study, 119 women).

AUTHORS' CONCLUSIONS

The quality of the evidence was poor, but the findings suggest that the combination of antacids plus H2 antagonists was more effective than no intervention, and superior to antacids alone in preventing low gastric pH. However, none of the studies assessed potential adverse effects or substantive clinical outcomes. These findings are relevant for all women undergoing caesarean section under general anaesthesia.

Comparison of intrathecal levobupivacaine combined with sufentanil, fentanyl, or placebo for elective caesarean section: a prospective, randomized, double-blind, controlled study

Background

The addition of opioids to local anesthetics contributes to the quality of spinal anesthesia and postoperative analgesia.

Objective

In our prospective, randomized, double-blind, controlled study, our aim was to compare the effect of low-dose sufentanil plus levobupivacaine or a fentanyl plus levobupivacaine mixture on anesthesia quality, block characteristics, newborn and mother well-being, surgeon satisfaction, and duration of postoperative analgesia.

Methods

Ninety-three patients were randomized into 3 groups (n = 31). Patients in Group C received 0.5% levobupivacaine (2.2 ± 0.2 mL), Group S received 2.5 µg sufentanil plus 0.5% levobupivacaine (2.2 ± 0.2 mL), and Group F received 10 µg fentanyl plus 0.5% levobupivacaine (2.2 ± 0.2 mL) intrathecally completed to a volume of 3 mL with the addition of saline in all groups. Patients’ demographics, sensory and motor block characteristics, hemodynamics, Apgar scores, umbilical blood gas values, maternal side effects, surgeon satisfaction score, time to first analgesia requirement, and additional analgesic use within 24 hours were recorded.

Results

In Group S and Group F, target levels of sensory and motor block were achieved more rapidly (P < 0.001). The hemodynamic values were lower (P < 0.05), and the duration of sensory blockade and the time of first analgesic requirement were longer (P < 0.001) in Group S. Additional analgesic requirement during first 24-hour period was lowest in Group S, and highest in Group C (P < 0.001). Apgar scores and umbilical blood gas samples were similar between groups. Postoperative pruritus was more frequent in Group S (P < 0.001) and surgeon satisfaction score was significantly lower in Group C (P = 0.003).

Conclusions

We suggest that the addition of sufentanil and fentanyl to intrathecal levobupivacaine during caesarean section surgery is more effective than the administration of levobupivacaine alone. The addition of sufentanil to levobupivacaine allowed rapid onset time for sensory and motor block levels. It also extended the duration of postoperative analgesia and led to a decrease in total analgesic requirement. ClinicalTrials.gov identifier: NCT01858090.

A study to compare the analgesic efficacy of intrathecal bupivacaine alone with intrathecal bupivacaine midazolam combination in patients undergoing elective infraumbilical surgery

Spinal anaesthesia, which is one of the techniques for infraumbilical surgeries, is most commonly criticized for limited duration of postoperative analgesia. Several adjuvants have been tried along with local anesthetic for prolonging the duration of analgesia. In this study, we have observed the effect of midazolam as an adjuvant in patients undergoing infraumbilical surgery. In this prospective, randomized, double blinded, and parallel group and open label study of 90 adult patients aged 18–60 years, of American Society of Anaesthesiologists (ASA) status I and II, scheduled for elective infraumbilical surgery, were randomly allocated in two groups. Each patient in group “B” received hyperbaric bupivacaine 12.5 mg along with 0.4 mL of normal saline in the subarachnoid block, and patients of group “BM” received 12.5 mg hyperbaric bupivacaine along with preservative free midazolam 0.4 mL (2 mg). We found that use of midazolam as adjuvant with the local anesthetic in spinal anaesthesia significantly increases the duration of analgesia (median 320 min versus 220 min) and motor block (median 255 min versus 195 min) but decreases the incidence of postoperative nausea-vomiting (PONV).

Hyperbaric articaine with or without fentanyl in spinal anaesthesia: patient and observer blinded comparison

BACKGROUND

The rapid and short-acting local anaesthetic articaine is a feasible spinal anaesthetic for day-case open inguinal herniorrhaphy (OIH). We hypothesised that similarly to other spinal local anaesthetics, the addition of fentanyl may prolong articaine spinal analgesia without prolonging motor block.

METHODS

We performed a randomised, controlled study in 100 adult patients undergoing OIH. Spinal anaesthesia was induced by injecting hyperbaric articaine 72 mg with (Group A + F) or without (Group A) fentanyl 10 μg with the patient in lateral decubitus position. The distribution of sensory block was tested using pinprick and controlled by tilting the operating table 10 up or down. Motor block testing was based on the patient's ability to flex knees and ankles. Rescue analgesic was intravenous (i.v.) fentanyl. Pain scores were registered, and i.v. paracetamol 1 g was given as the first post-operative analgesic.

RESULTS

There were no differences (A + F vs. A) in the maximum median extension of the sensory block (T5 vs. T5), mean duration of sensory block ≥ T10 (76 min vs. 73 min), or total duration of sensory (146 min vs. 146 min) or motor block (99 min vs. 107 min). Fewer patients in Group A + F needed fentanyl (5 vs. 14, P < 0.05) perioperatively or paracetamol (3 vs. 18, P < 0.001) post-operatively.

CONCLUSION

Fentanyl 10 μg added to spinal hyperbaric articaine improved analgesia and reduced analgesic consumption during and after OIH. Fentanyl did not prolong motor block or delay recovery.

Comparison of clinical effects according to the dosage of sufentanil added to 0.5% hyperbaric bupivacaine for spinal anesthesia in patients undergoing cesarean section

Background

Subarachnoid block is a widely used technique for cesarean section. To improve the quality of analgesia and prolong the duration of analgesia, addition of intrathecal opioids to local anesthetics has been encouraged. We compared the effects of sufentanil 2.5 µg and 5 µg, which were added to intrathecal hyperbaric bupivacaine.

Methods

We enrolled 105 full term parturients were randomly divided into 3 groups: Group 1 (control), Group 2 (sufentanil 2.5 µg), and Group 3 (sufentanil 5 µg). In every group, 0.5% heavy bupivacaine was added according to the adjusted dose regimen. We determined the maximum level of sensory block and motor block, the quality of intraoperative analgesia, the duration of effective analgesia and side effects.

Results

There were no significant differences among the 3 groups in the maximum level of the sensory block and motor block. Recovery rate of the sensory block, however, was significantly slower in Group 3 than Group 1. Quality of intraopertive analgesia, muscle relaxation, and duration of effective analgesia were enhanced by increasing the dosage of intrathecal sufentanil. Frequencies of hypotension, maximum sedation level, and pruritus were directly related to the dosage of intrathecal sufentanil, whereas nausea and vomiting occurred only in the groups using sufentanil.

Conclusions

The addition of sufentanil 2.5 µg for spinal anesthesia provides adequate intraoperative analgesia and good postoperative analgesia with minimal adverse effects on the mother.

Interventions for preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section

BACKGROUND

Nausea and vomiting are distressing symptoms which are experienced commonly during caesarean section under regional anaesthesia and can also occur in the period following the procedure. 

OBJECTIVES

To assess the efficacy of pharmacological and non-pharmacological interventions given prophylactically to prevent nausea and vomiting in women undergoing regional anaesthesia for caesarean section.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (27 February 2012) and reference lists of identified studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and excluded quasi-RCTs and cross-over studies.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Data entry was checked.  

MAIN RESULTS

Fifty-two studies met the inclusion criteria but only 41 studies, involving 5046 women, provided useable data for the review involving women having caesareans under regional anaesthesia. The majority of the studies involved women undergoing elective caesarean section. Only two studies included emergency surgery, however, they did not stratify data according to type of surgery. The studies covered numerous comparisons, but the majority of studies involved 5-HT(3) receptor antagonists, dopamine receptor antagonists, corticosteroids or acupressure. Studies were mainly small and of unclear quality.Three classes of intervention were found to be effective in at least three out of four of our primary outcomes (intraoperative nausea, intraoperative vomiting, postoperative nausea and postoperative vomiting). These interventions were 5-HT(3) antagonists, dopamine antagonists and sedatives. Other classes of intervention were effective for fewer than three of our primary outcomes.With 5-HT antagonists, we found a reduction in intraoperative nausea (average risk ratio (RR) 0.64, 95% confidence interval (CI) 0.46 to 0.88, eight studies, 720 women). There were also reductions in postoperative nausea (average RR 0.40, 95% CI 0.25 to 0.64, four studies, 405 women) and vomiting (average RR 0.50, 95% CI 0.32 to 0.77, five studies, 565 women). We did not detect a significant reduction in intraoperative vomiting (average RR 0.56, 95% CI 0.31 to 1.00, seven studies, 668 women).Dopamine antagonists demonstrated a reduction in intraoperative nausea (average RR 0.38, 95% CI 0.25 to 0.57, nine studies, 636 women) and intraoperative vomiting (average 0.39, 95% CI 0.24 to 0.64, eight studies, 536 women), with similar reductions in postoperative nausea (average RR 0.60, 95% CI 0.40 to 0.91, five studies, 412 women) and vomiting (average RR 0.57, 95% CI 0.36 to 0.91, six studies, 472 women). These differences were observed with both metoclopramide and droperidol.Sedatives (most commonly propofol) demonstrated a reduction in intraoperative nausea (average RR 0.71, 95% CI 0.52 to 0.96, four studies, 285 women) and intraoperative vomiting (average RR 0.42, 95% CI 0.26 to 0.68, four studies, 285 women), also with a reduction in postoperative nausea (average RR 0.25, 95% CI 0.09 to 0.71, two studies 145 women) and vomiting (average RR 0.09, 95% CI 0.03 to 0.28, two studies, 145 women).Acupressure was found to be effective for intraoperative nausea (average RR 0.59, 95% CI 0.38 to 0.90, six studies, 649 women) but not postoperative nausea (average RR 0.83, 95% CI 0.68 to 1.00, three studies, 429 women). Acupressure was not effective at reducing vomiting either intraoperatively (average RR 0.74, 95% CI 0.46 to 1.18, six studies, 649 women) or postoperatively (average RR 0.69, 95% CI 0.45 to 1.06, three studies, 429 women).Other effective intervention classes included corticosteroids, antihistamines, and anticholinergics.There were insufficient data to demonstrate any class of intervention was superior to another. There were no significant differences observed in the comparison of combined versus single interventions.Few studies assessed our secondary outcomes or the incidence of adverse effects. However, one study showed an increase in respiratory depression with sedation (midazolam) compared with dopamine antagonists.

AUTHORS' CONCLUSIONS

This review indicates that many different interventions have efficacy in preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section. There is little evidence that combinations of treatment are better than single agents.

Combination of low-dose bupivacaine and opioids provides satisfactory analgesia with less intraoperative hypotension for spinal anesthesia in cesarean section

AIMS

This meta-analysis was undertaken to compare the three most common drug regimens of bupivacaine in spinal anesthesia for cesarean section: high-dose bupivacaine (≥10 mg, HB), low-dose bupivacaine (<10 mg, LB) and combination of low-dose bupivacaine and opioids (LBO).

METHODS

Databases of MEDLINE, EMBASE, and Cochrane Library were searched (updated on October 30, 2011). Primary endpoints were the incidence of intraoperative hypotension and analgesia efficacy. Pooled risk ratio (RR) or standard mean difference and their 95% confidence intervals (95% CI) were calculated. A RR <1 indicates that LB or LBO regimen is associated with less intraoperative complications and better anesthesia or analgesia efficacy.

RESULTS

A total of 11 randomized controlled trials including 605 parturients were analyzed. Results of this meta-analysis showed that compared with HB regimen, LB regimen decreased the incidence of intraoperative hypotension (RR = 0.64, 95% CI: 0.42-0.96) with less satisfactory analgesia (fixed model, RR = 1.50, 95% CI: 1.14-1.98). LBO regimen significantly reduced the incidence of intraoperative hypotension (RR = 0.52, 95% CI: 0.33-0.82) with reliable analgesia efficacy (RR = 2.56, 95% CI: 0.77-8.48).

CONCLUSION

Compared with conventional HB regimen and LB regimen, LBO regimen not only reduced intraoperative hypotension but also provided reliable analgesia. Therefore, LBO regimen should be considered as the preferred drug combination for spinal anesthesia in cesarean section.

Intrathecal fentanyl added to bupivacaine and morphine for cesarean delivery may induce a subtle acute opioid tolerance

BACKGROUND

Previous studies have demonstrated that the addition of intrathecal fentanyl to a spinal anesthetic for cesarean delivery improves intraoperative analgesia. However, intrathecal fentanyl may induce acute tolerance to opioids. The objective of this study was to investigate whether the addition of intrathecal fentanyl to spinal anesthesia with intrathecal morphine increases postoperative analgesic requirements and pain scores.

METHODS

In this randomized, double-blinded study, 40 women having elective cesarean delivery were enrolled. Patients received spinal anesthesia with hyperbaric bupivacaine 12 mg, morphine 200 μg, and fentanyl 0, 5, 10 or 25 μg. Each patient received intravenous patient-controlled analgesia morphine for 24h postoperatively. Outcome measures included postoperative morphine usage and pain scores, as well as intraoperative pain, nausea, hypotension and vasopressor use.

RESULTS

Total morphine use over the 24-h post-spinal study period was similar among the study groups (P=0.129). Postoperative pain scores were higher in patients receiving fentanyl 5, 10 and 25 μg compared to fentanyl 0 μg control group (P=0.003).

CONCLUSIONS

The study results suggest that intrathecal fentanyl may induce acute tolerance to intrathecal morphine. However, because there was no difference in postoperative analgesia requirement and the difference in pain scores was small, the clinical significance of this finding is uncertain.

A Comparative study of intrathecal dexmedetomidine and fentanyl as adjuvants to Bupivacaine

Background:

Various adjuvants have been used with local anesthetics in spinal anesthesia to avoid intraoperative visceral and somatic pain and to provide prolonged postoperative analgesia. Dexmedetomidine, the new highly selective α2-agonist drug, is now being used as a neuraxial adjuvant. The aim of this study was to evaluate the onset and duration of sensory and motor block, hemodynamic effect, postoperative analgesia, and adverse effects of dexmedetomidine or fentanyl given intrathecally with hyperbaric 0.5% bupivacaine.

Materials and Methods:

Sixty patients classified in American Society of Anesthesiologists classes I and II scheduled for lower abdominal surgeries were studied. Patients were randomly allocated to receive either 12.5 mg hyperbaric bupivacaine plus 5 μg dexmedetomidine (group D, n = 30) or 12.5 mg hyperbaric bupivacaine plus 25 μg fentanyl (group F, n = 30) intrathecal.

Results:

Patients in dexmedetomidine group (D) had a significantly longer sensory and motor block time than patients in fentanyl group (F). The mean time of sensory regression to S1 was 476±23 min in group D and 187±12 min in group F (P<0.001). The regression time of motor block to reach modified Bromage 0 was 421±21 min in group D and 149±18 min in group F (P<0.001).

Conclusions:

Intrathecal dexmedetomidine is associated with prolonged motor and sensory block, hemodynamic stability, and reduced demand for rescue analgesics in 24 h as compared to fentanyl.

Comparison of fentanyl and sufentanil added to 0.5% hyperbaric bupivacaine for spinal anesthesia in patients undergoing cesarean section

BACKGROUND

Subarachnoid block is widely used for cesarean section due to the rapid induction, the complete analgesia, the low failure rate and the prevention of aspiration pneumonia. The addition of intrathecal opioids to local anesthetics seems to improve the quality of analgesia & prolong the duration of analgesia. Therefore we compared the effects of fentanyl 20 µg and sufentanil 2.5 µg, which were added to intrathecal hyperbaric bupivacaine.

METHODS

SEVENTY TWO HEALTHY TERM PARTURIENTS WERE RANDOMLY DIVIDED INTO THREE GROUPS: Group C (control), Group F (fentanyl 20 µg) and Group S (sufentanil 2.5 µg). In every group, 0.5% heavy bupivacaine was added according to the adjusted dose regimen by Harten et al. We observed the maximal level of the sensory block and motor block, the quality of intraoperative analgesia, the duration of effective analgesia and the side effects.

RESULTS

There were significant differences between the control and the fentanyl 20 µg and sufentanil 2.5 µg groups for the degree of muscle relaxation, the quality of intraoperative analgesia, the maximal sedation level and the duration of effective analgesia. The frequencies of side effects such as nausea and pruritis in the opioid groups were higher than those in the control group. But there were no differences between fentanyl 20 µg and sufentanil 2.5 µg for the frequencies of nausea and pruritis.

CONCLUSIONS

The addition of fentanyl 20 µg or sufentanil 2.5 µg for spinal anesthesia provides adequate intraoperative analgesia without significant adverse effects on the mother and neonate.

Combining Intrathecal Bupivacaine and Meperidine during Caesarean Section to Prevent Spinal Anaesthesia-Induced Hypotension and other Side-Effects

This study compared intrathecal hyperbaric bupivacaine with low-dose intrathecal plain bupivacaine plus different doses of meperidine (pethidine), administered sequentially, with regard to blood pressure stability, post-operative analgesia and incidence of side-effects in 80 parturients undergoing caesarean section. Patients were randomly assigned to one of four groups ( n = 20 each group): the HB group received 10 mg hyperbaric bupivacaine intrathecally; the BM35, BM30 and BM25 groups received 5 mg plain bupivacaine plus 35, 30 or 25 mg of meperidine intrathecally, respectively. The incidence of hypotension in the BM25 group was significantly lower than in the HB group. Nausea and vomiting were less prevalent in the BM25 group than in the HB and BM35 groups. In conclusion, sequential administration of 5 mg plain bupivacaine and 25 mg meperidine intrathecally provided better blood pressure stability and a lower incidence of side-effects than bupivacaine alone, without affecting quality of anaesthesia or surgical and patient satisfaction.

Spinal and intravenous midazolan anesthetic effects on fentanyl/ ligdocaine regional anesthesia following back minor orthopedic surgery

OBJECTIVES: the present study was designed to evaluate the usefulness of intravenous and intrathecal midazolan as an adjunct to intrathecal ligdocaine, with or without intrathecal fentanyl. METHODS: double-blind study, institutional approval and informed consent; 40 patients scheduled for minor lumbar orthopedic surgery were randomly assigned to one of five groups (n=8). Patients were premedicated with a 4 mL final intravenous volume (saline or midazolan). Spinal anaesthesia was administered to a 3 mL final volume - 75 mg of lidocaina plus either 33 mg fentanyl or 500 mg midazolan diluted in saline (0,9%) - with the patient in sitting position. The latency time for onset of the block (LT), time to progress to T10 sensory level (TT10), duration of the block (Bl), duration of effective analgesia (An), the subjective degree of intraoperative sedation, level of alertness, concentration level and degree of anxiety were specifically measured. P<0.05 was considered significant. RESULTS: the addition of midazolan to the intrathecal injection in the absence of fentanyl was the only procedure which caused a statistically significant reduction in LT (p<0.002) and TT10 (p<0.001). Intrathecal midazolan increased the blockade time both with (p<0.05) and without (p<0.02) intrathecal fentanyl, but, when given intravenously, this effect failed to reach statistical significance (p>0,05). Both intrathecal fentanyl and midazolan increased the duration of analgesia (p<0.01). With respect to the subjective measures, group 1 served as the control group, demonstrating an alert, fully awake patient who was able to concentrate but showed some anxiety. CONCLUSIONS: while all additional treatments resulted in a relaxed patient, only those given intrathecal midazolan remained fully awake, alert and able to concentrate. Intrathecal fentanyl with saline premedication or intravenous midazolan premedication resulted in decreased alertness and inability to concentrate, as well as sleepiness, which was more extreme in the case of those patients given intravenous midazolan.

Interventions at caesarean section for reducing the risk of aspiration pneumonitis

BACKGROUND

Aspiration pneumonitis is a syndrome resulting from the inhalation of gastric contents. The incidence in obstetric anaesthesia has fallen, largely due to improved anaesthetic techniques and the increased use of regional anaesthesia at caesarean section. However, aspiration pneumonitis is still a cause of maternal morbidity and mortality, and it is important to use effective prophylaxis.

OBJECTIVES

To determine whether interventions given prior to caesarean section reduce the risk of aspiration pneumonitis in women with an uncomplicated pregnancy.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (April 2009).

SELECTION CRITERIA

Randomised controlled trials were included. Quasi-randomised trials were excluded.

DATA COLLECTION AND ANALYSIS

Authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Data entry was checked.

MAIN RESULTS

Twenty-two studies, involving 2658 women, are included, all having a caesarean section under general anaesthesia. The studies covered a number of comparisons, but were mostly small and of unclear or poor quality.When compared to no treatment or placebo, there was a significant reduction in the risk of intragastric pH < 2.5 with antacids (risk ratio (RR) 0.17, 95% confidence interval (CI) 0.09 to 0.32, two studies, 108 women), H(2) antagonists (RR 0.09, 95% CI 0.05 to 0.18, two studies, 170 women) and proton pump antagonists (RR 0.26, 95% CI 0.14 to 0.46, one study 80 women). H(2) antagonists were associated with a reduced the risk of intragastric pH < 2.5 at intubation when compared with proton pump antagonists (RR 0.39, 95% CI 0.16 to 0.97, one study, 120 women), but compared with antacids the findings were unclear. The combined use of 'antacids plus H(2) antagonists' was associated with a significant reduction in the risk of intragastric pH < 2.5 at intubation when compared with placebo (RR 0.02, 95% CI 0.00 to 0.15, one study, 89 women) or compared with antacids alone (RR 0.12, 95% CI 0.02 to 0.92, one study, 119 women).

AUTHORS' CONCLUSIONS

The quality of the evidence was poor, but the findings suggest that the combination of antacids plus H(2) antagonists was more effective than no intervention, and superior to antacids alone in preventing low gastric pH. However, none of the studies assessed potential adverse effects or substantive clinical outcomes. These findings are relevant for all women undergoing caesarean section under general anaesthesia.