Efficacy and safety of epidural clonidine by continuous infusion or patient-controlled analgesia in labor: A meta-analysis of randomized controlled trials.

BACKGROUND: Epidural clonidine improves analgesia but may induce adverse effects in labor. OBJECTIVE: To evaluate the efficacy and safety of epidural clonidine as local anesthetics (LA) adjuvant by continuous infusion or patient-controlled epidural analgesia (PCEA) in labor. SEARCH STRATEGY: PubMed, Embase, Web of Science, and CENTRAL were searched from inception to May 10, 2022 without language restriction; references of the retrieved studies were hand searched. SELECTION CRITERIA: Randomized controlled trials (RCTs) comparing epidural LA with and without clonidine using continuous infusion or PCEA in labor were included. DATA COLLECTION AND ANALYSIS: A random effects model was used to pool the data on analgesia and adverse effects. MAIN RESULTS: Eight RCTs were included. Clonidine did not reduce the incidence of parturients requiring additional epidural boluses but reduced LA consumption and pain scores without increasing adverse effects, except for a higher incidence of instrumental delivery when clonidine was combined with LA and opioid (risk ratio 2.38, 95% confidence interval 1.26-4.50). Clonidine offered similar analgesia to opioids but had reduced opioid-related adverse effects. Trial sequential analysis showed that the evidence was insufficient. CONCLUSIONS: Epidural clonidine by continuous infusion or PCEA does not increase significant adverse effects and offers similar analgesia to opioids in labor. PROSPERO registration no. CRD42022306565.

Prevalence of risk stomach in laboring women allowed to unrestrictive oral intake: a comparative cross-sectional study.

BACKGROUND: Although restricting food intake during labor is recommended by guidelines, intrapartum starvation has not been popular in some regions. We conducted this comparative cross-sectional study to determine the prevalence of risk stomach in non-fasted laboring women compared with fasted non-laboring women using gastric ultrasound. METHODS: Ultrasound examination of the antrum was performed in 50 term fasted non-laboring women before elective cesarean delivery and 50 laboring women allowed to eat and drink during active labor. Examinations consisted of the qualitative (antral grades, 0-3) and quantitative evaluation (antral cross-sectional area and calculated gastric volume) in the supine and right lateral decubitus (RLD) position. A risk stomach was defined as an antral grade ≥ 2 or grade 1 with gastric volume ≥ 1.5 ml· kg- 1. RESULTS: No non-laboring women had grade ≥ 2, while 34 (68%) laboring women had grade ≥ 2. Nine (18%) non-laboring and 40 (80%) laboring women presented risk stomach (P < 0.001) (risk ratio: 4.4, 95% CI 2.4-8.2). Compared with non-laboring women, laboring women had larger antral area at "empty" stomach (grade 0) (437 mm2 vs.350 mm2 in supine, 571 mm2 vs.480 mm2 in RLD, P < 0.05) and cut-off values of antral area to discriminate a risk stomach (510 mm2 vs. 453 mm2 in supine, 670 mm2 vs. 605 mm2 in RLD). CONCLUSIONS: This study confirms a higher prevalence of risk stomach presents in laboring women under a liberal eating policy, gastric ultrasound is therefore useful for this risk population if general anesthesia is required unexpectedly.

Impact of Transversus Abdominis Plane Block With Bupivacaine or Ropivacaine Versus Intrathecal Morphine on Opioid-related Side Effects After Cesarean Delivery: A Meta-analysis of Randomized Controlled Trials.

OBJECTIVES: Intrathecal morphine (ITM) is frequently associated with side effects such as postoperative nausea and vomiting (PONV) and pruritus. The aim of this meta-analysis was to compare the impact of transversus abdominis plane (TAP) block versus ITM on side effects following cesarean delivery. MATERIALS AND METHODS: PubMed, Embase, Web of Science, and CENTRAL were searched for randomized controlled trials that compared TAP with ITM for cesarean delivery. The primary outcomes were opioid-related side effects. The secondary outcomes included pain scores, opioid consumption, patient satisfaction, and time to the first analgesia request. RESULTS: Seven studies involving 660 patients were included. TAP blocks were performed with bupivacaine or ropivacaine. There was less PONV with TAP versus ITM (risk ratio [RR]=0.45, 95% confidence interval [CI]: 0.33-0.63, P<0.001; I2=0%), but no significant difference in pruritus (RR=0.76, 95% CI: 0.49-1.18, P=0.22; I2=78%) and sedation (RR=0.44, 95% CI: 0.19-1.00, P=0.05; I2=0%). TAP had a greater morphine consumption in 24 hours (mean difference: 5.80 mg; 95% CI: 1.38-10.22 mg, P=0.01; I2=89%) and higher pain score at rest at 6 hours (mean difference: 0.70, 95% CI: 0.39-1.02, P<0.001; I2=56%), but similar pain at rest at 24 hours and on movement compared with ITM. No differences were found in time to first analgesia and patient satisfaction. DISCUSSION: Compared with ITM, TAP block is associated with less PONV but inferior early analgesia after cesarean delivery. However, the heterogeneity among the studies highlights the need for more well-designed studies to obtain more robust conclusions.

A prediction model using machine-learning algorithm for assessing intrathecal hyperbaric bupivacaine dose during cesarean section.

BACKGROUND: The intrathecal hyperbaric bupivacaine dosage for cesarean section is difficult to predetermine. This study aimed to develop a decision-support model using a machine-learning algorithm for assessing intrathecal hyperbaric bupivacaine dose based on physical variables during cesarean section. METHODS: Term parturients presenting for elective cesarean section under spinal anaesthesia were enrolled. Spinal anesthesia was performed at the L3/4 interspace with 0.5% hyperbaric bupivacaine at dosages determined by the anesthesiologist. A spinal spread level between T4-T6 was considered the appropriate block level. We used a machine-learning algorithm to identify relevant parameters. The dataset was split into derivation (80%) and validation (20%) cohorts. A decision-support model was developed for obtaining the regression equation between optimized intrathecal 0.5% hyperbaric bupivacaine volume and physical variables. RESULTS: A total of 684 parturients were included, of whom 516 (75.44%) and 168 (24.56%) had block levels between T4 and T6, and less than T6 or higher than T4, respectively. The appropriate block level rate was 75.44%, with the mean bupivacaine volume [1.965, 95%CI (1.945,1.984)]ml. In lasso regression, based on the principle of predicting a reasonable dose of intrathecal bupivacaine with fewer physical variables, the model is "Y=0.5922+ 0.055117* X1-0.017599*X2" (Y: bupivacaine volume; X1: vertebral column length; X2: abdominal girth), with λ 0.055, MSE 0.0087, and R2 0.807. CONCLUSIONS: After applying a machine-learning algorithm, we developed a decision model with R2 0.8070 and MSE due to error 0.0087 using abdominal girth and vertebral column length for predicting the optimized intrathecal 0.5% hyperbaric bupivacaine dosage during term cesarean sections.

Remifentanil for Carboprost-Induced Adverse Reactions During Cesarean Delivery Under Combined Spinal-Epidural Anesthesia.

PURPOSE: Carboprost may induce adverse reactions when used to treat postpartum hemorrhage. We aimed to explore the effects of intravenous infusion of low-dose remifentanil to prevent such reactions. METHODS: We enrolled parturient patients scheduled for elective cesarean section. Anesthesiologist administered combined spinal epidurals at the L3/4 interspace, with 0.5% hyperbaric bupivacaine subarachnoid space injections (1.5-2.5 ml). We randomly divided parturient patients, administered carboprost during surgery, into the remifentanil group (group R) and the control group (group C). Patients in group R received an intravenous target-controlled infusion of remifentanil (target effect-site concentration, 1.5 ng/ml) simultaneously with a carboprost tromethamine injection (250 µg). Patients in group C received a normal saline infusion with carboprost. We recorded and analyzed the incidence of carboprost-related adverse reactions (vomiting, nausea, chest congestion, flushing, hypertension, tachycardia, cough, and shivering), and assessed patient comfort using a numerical rating scale ([NRS], on which 0 was very uncomfortable and 10 was very comfortable). RESULTS: After applying inclusion and exclusion criteria, we conducted statistical analysis of the data from 70 women. The incidence of vomiting was significantly lower in group R than in group C (14.3 vs. 51.4%, p < 0.01); and the incidence of nausea, chest congestion, facial flushing, and hypertension were significantly lower in group R than in group C (all p < 0.01). Furthermore, the patients' comfort scores were significantly higher in group R than in group C (8.0 ± 1.8 vs. 3.6 ± 2.1, p < 0.01). CONCLUSION: Our results demonstrate that an intravenous low-dose remifentanil infusion can effectively prevent carboprost-related adverse reactions during cesarean delivery under combined spinal and epidural anesthesia. CLINICAL TRIAL REGISTRATION: We pre-registered this study at http://www.chictr.org.cn/showproj.aspx?proj=27707 (ChiCTR1800016292).

A randomized comparison of caudal block by sacral hiatus injection under ultrasound guidance with traditional sacral canal injection in children.

BACKGROUND: There is a risk of inadvertent dural or vascular puncture for the traditional single-shot caudal block performed by inserting the needle into the sacral canal through the sacral hiatus. This prospective, randomized study was to evaluate the clinical feasibility of the hiatus injection under ultrasound guidance for caudal block in children. METHODS: 140 ASA I-II children undergoing inguinal hernia repair were randomly allocated to one of two groups (Group C or Group H, n = 70). 1 ml·kg(-1) of 0.25% ropivacaine was injected after the needle was inserted into the sacral canal in Group C, or after the needle pierced the sacrococcygeal ligament under a transverse ultrasound view in Group H. Success rate of block, puncture frequency, complications, and durations of block were recorded. RESULTS: The success rate of block was similar between two groups (95.7% in Group C vs 92.8% in Group H, P > 0.05). The first puncture success rate was higher, and the durations of block were shorter in Group H than in Group C (92.8% vs 60% and 145 ± 23s vs 164 ± 31s, respectively P < 0.05). Bloody puncture had an incidence of 18.6% in Group C and 5.7% in Group H (P < 0.05). Subcutaneous bulging occurred in six patients (7.1%) in Group C but none in Group H (P < 0.05). CONCLUSIONS: Sacral hiatus injection offers a reliable caudal block for pediatric inguinal hernia repair with the advantages of easier performance and fewer complications compared with traditional sacral canal injection.

[Study of symbolic element in roasting slag of pyrite by inductively coupled plasma mass spectrometry].

In the present paper, the correlations between sixteen elements from the dry method roasted dust-slag of pyrite and sixteen elements from the soil layer near and far from the store area were studied by ICP-MS. Similar radio and outstanding different radio of the elements between the dust-slag and the soil were studied too. It was discovered that in the pollution soil layer Tl, Cd, Cs, Cu, Zn, Mn, Pb and Ni were easy to be identified and had similar radio with the elements in the dust-slag. But only Tl, Cd, Zn and Ni are suitable for criterion of element similar properties. In dust-slag and soil, distinct composition element radios of Tl, Cs, Co, Mo, Zn, Cr, V, Sr, Sb, Pb, Rb, Mn and Ni had striking differentiation. Only Tl, V, Sb and Cu corresponded to both the uncorrelated elements analysis of surface layer and middle-base layer soil. Tl could be used as an inspection target of similar elements and outstanding different elements between the dust-slag and the soil in the meanwhile. So we suggested that Tl can be used as a symbolic element in the roasting dust-slag of pyrite to find the dust-slag of pyrite in dust-recognition and to differentiate the metallurgy dust of pyrite and soil dust.

Antiallodynic effects of propentofylline Elicited by interrupting spinal glial function in a rat model of bone cancer pain.

The activation of microglia and astrocytes in the spinal cord is involved in the progress of cancer pain. Propentofylline (PPF), a glial modulating agent, alleviates pain hypersensitivity in neuropathic pain models. The present study investigated the potential roles of PPF in a preclinical rat model of bone caner pain established by inoculating Walker 256 cells into the left tibia. At day 9 postinoculation, single administration of PPF (10 µg/10 µl, i.t.) significantly but transiently suppressed mechanical allodynia induced by bone cancer. Repeated application of PPF (10 µg/10 µl, i.t., once daily from days 9 to 12) persistently relieved mechanical allodynia on the side ipsilateral to surgery. Immunohistochemistry and ELISA showed that microglia and astrocytes in the spinal cord were activated, and the production of glia-derived proinflammatory cytokines interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor-α (TNF-α) markedly increased at day 12 postinoculation in the cancer group. Intrathecal injection of PPF (10 µg/10 µl) significantly inhibited the activation of spinal glial cells and the expression of proinflammatory cytokines. These results suggest that the glial modulating agent PPF has antiallodynic effects on bone cancer pain and has potential utility for clinical treatment of cancer pain.

Comparison of bupivacaine, ropivacaine and levobupivacaine with sufentanil for patient-controlled epidural analgesia during labor: a randomized clinical trial.

BACKGROUND: Ropivacaine and levobupivacaine have been introduced into obstetric analgesic practice with the proposed advantages of causing less motor block and toxicity compared with bupivacaine. However, it is still controversial whether both anesthetics are associated with any clinical benefit relative to bupivacaine for labor analgesia. This study aimed to compare the analgesic efficacy, motor block and side effects of bupivacaine, ropivacaine and levobupivacaine at lower concentrations for patient-controlled epidural labor analgesia. METHODS: Four hundred and fifty nulliparous parturients were enrolled in this randomized clinical trial. A concentration of 0.05%, 0.075%, 0.1%, 0.125% or 0.15% of either bupivacaine (Group B), ropivacaine (Group R) or levobupivacaine (Group L) with sufentanil 0.5 microg/ml was epidurally administered by patient-controlled analgesia mode. Effective analgesia was defined as a visual analogue scale score was 0.05). The relative median potency was bupivacaine/ropivacaine: 0.828 (0.602-1.091), bupivacaine/levobupivacaine: 0.845 (0.617-1.12), ropivacaine/levobupivacaine: 1.021 (0.774-1.354), respectively. However, a significantly less number of effective analgesia and higher hourly local anesthetic use were observed in the concentration of 0.05% than those of >or=0.1% within each group (P<0.05). CONCLUSIONS: Using patient-controlled epidural analgesia, lower concentrations of bupivacaine, ropivacaine and levobupivacaine with sufentanil produce similar analgesia and motor block and safety for labor analgesia. The analgesic efficacy mainly depends on the concentration rather than the type of anesthetics.

[Distribution and partition of polycyclic aromatic hydrocarbons (PAHs) in the Gaoyao section of Xijiang River].

To obtain the seasonal and vertical distribution and partition of PAHs between dissolved phase and particle phase in Xijiang River basin, water columns were collected during flood seasons (August, 2003 and July, 2004) and dry seasons (November, 2003 and Mar, 2004) from Gaoyao section of Xijiang River. The average PAHs concentrations in dissolved phase and particle phase were 21.7-138 ng x L(-1), 40.9-664.8 microg x kg(-1), respectively. Total PAHs concentrations (both particle phase and dissolved phase) were higher in flood seasons than that in dry seasons. No variation was found for dissolved PAHs in vertical distribution. However, a same trend of vertical distribution was observed for particle PAHs with the maximum concentration in middle layer and minimum in surface layer of water column. With increasing of content of suspended particle matter (SPM), both dissolved and particle PAHs concentration increased. In the dissolved phase, the predominant PAHs were 3 ring PAHs. While in the particle phase, 3-4 ring PAHs were the dominant PAHs. The partition coefficient (K(p)) had no correlation with the particle organic carbon content of SPM (R2 0.000 1-0.2), but influenced by concentrations of suspended particle matters and dissolved organic carbon, especially black carbon in dissolved phase (R2 0.15 -0.36). A majority of values of lg K(oc) in different seasons exceeded upper limit based on typical model of equilibrium distribution. Except the season of November 2003 (R2 0.000 4-0.12, p < 0.001), the organic carbon normalized distribution coefficients (K(oc)) computed for the PAHs were correlated well with their octanol-water partition coefficient (K(ow))(R2 0.29-0.91, p < 0.05). The lipophilic ability of SPM was stronger in flood seasons than that in dry seasons.

[Application of ICP-MS in evaluating element contamination in soils].

The Yunfu pyrite was the second biggest pyrite bed in the world. Plants using industrial ore of the Yunfu pyrite are distributed in many sections across the country. In the present paper, elements V, Cr, Co, Cu, Zn, Mo, Cd, Sb, Rb and Cs in soil profiles in slag disposing area of a sulfuric acid plant using industrial ore of theYunfu pyrite were studied. A method for simultaneously determination of metals and some reference elements in soils by ICP-MS was developed. The correlations between the metals and their reference elements were fast found. Enrichment factors were applied for evaluating the degree of soil contamination, and the problem about choosing contamination elements background values was pointed out. The results indicated that element V showed apparent and serious pollution, The Co showed middle degree pollution, and there has been a trend of apparent pollution. The Cr, Mo and Cd showed pollution between light degree and middle degree. The Zn and Sb showed light degree pollution, and there was a latent trend of middle degree pollution. The Cu showed light degree pollution. The high enrichment points of the V and the Cr were observed in the upper part (4.0-10.5 cm) and deep part of soil profiles (44.0-75.5 cm). Those of Co and Mo were found in the surface of soil profiles (0-5.0 cm), middle-upper part (9.5-10.5 cm) and middle part (29.5-46.0 cm), while those of Cd and Cu occurred just in the middle of soil profiles (29.5-46.0 cm). The formation of highly enrichment points of contamination elements in the soil profiles was the result of leaching and accumulating effect of the metals released from slag and the residual metals of highly weathered red soils. Most of pollution of V in the soil was contributed by the V in soil bed. Part of the V pollution in the soil was supplied by leaching and accumulating effect of the V which came from catalyst with lost activity in sulfuric acid production volatilizing into slag.