Ultrasound evaluation of gastric emptying of high-energy semifluid solid beverage in parturients during labor at term: a randomized controlled trial.

PURPOSE: What to intake during labor is controversial. The purpose of this study was to compare the gastric emptying of high-energy semifluid solid beverage (HESSB) versus that of carbohydrate (CHO) solution of equal calories and volume by evaluating the gastric antral cross-sectional area (CSA) using ultrasonography in parturients during labor at term. METHODS: The study was conducted at a maternity and infant hospital between June and October 2020. Forty parturients scheduled for epidural labor analgesia during labor at term were randomly assigned to receive HESSB (300 mL, n = 20) or CHO (300 mL, n = 20). Gastric antral CSA was measured at baseline and 5, 30, 60, 90, and 120 min after consumption of the drink. The primary outcome was gastric antral CSA at 120 min in the HESSB group and CHO group. RESULTS: The gastric antral CSA between the HESSB group and CHO group at 120 min was not statistically significant (2.73 cm2 ± 0.55 vs. 2.55 cm2 ± 0.72, P = 0.061). All patients returned to baseline at 120 min after intake of 300 mL isocaloric HESSB and CHO, confirmed by evaluation of gastric antral CSA. The visual analog scale score for satiety was higher in the HESSB group (P < 0.001), with better taste satisfaction (7[5-8] vs. 5[4-6], P < 0.001). CONCLUSION: The change of gastric antral cross-sectional area after HESSB is similar to the corresponding calories and volume of CHO and the gastric emptying of HESSB can be emptied within 2 h with better taste satisfaction and satiety in pregnant women under labor analgesia.

Comment on: "Do maternal albumin levels affect post-operative complications after cesarean delivery?"

Hypoalbuminemia is often considered an independent risk factor for surgical site infections. This study first demonstrated that albumin level ≥ 3.3 g/dL was independently associated with adverse maternal outcomes. In this letter to the editor, we would like to raise some concerns about the study and clarify the interpretation of the results.

Ultrasound Assessment of Gastric Volume in Parturients After High-Flow Nasal Oxygen Therapy.

BACKGROUND: High-flow nasal oxygen (HFNO) therapy is widely used in critical care obstetrics to improve oxygenation. Much of the benefit of HFNO is linked to the creation of modest levels of positive airway pressure. Pregnant women are generally considered to be at high risk of regurgitation and aspiration. It is unknown whether HFNO may cause gas insufflation into the stomach and further increase this risk. Therefore, this study aimed to systematically evaluate the possible safety effects of HFNO on gastric volume in healthy fasted parturients. METHODS: Sixty fasted parturients scheduled for elective cesarean delivery were enrolled in an observer-blinded, prospective, interventional study. We used ultrasonography to assess changes of antral cross-sectional area (CSA) and gastric volume before and after a 20-minute treatment with HFNO at a rate of 50 L·min -1 . The primary outcome was the change in gastric volume from before to after HFNO therapy, and the secondary outcome was the distribution of antral grades. RESULTS: In semirecumbent right lateral position, the antral CSA at baseline and after treatment with HFNO was 3.81 (3.01-4.72) cm 2 and 3.79 (3.03-4.54) cm 2 , respectively. The estimated fluid volume at baseline and after treatment with HFNO was 38.51 (33.39-54.62) mL and 39.71 (32.00-52.82) mL, respectively. All participants had either a grade 0 or grade 1 antrum, and most of them had a grade 0 antrum. There was no significant difference in gastric volume and distribution of antral grades before and after HFNO therapy. Gastric air distension was not shown in any of the parturients either at baseline or after treatment with HFNO. CONCLUSIONS: Treatment with HFNO for 20 minutes at flow rates up to 50 L·min -1 did not increase gastric volume in term pregnant women breathing spontaneously when evaluated by gastric ultrasonography.

Factors influencing the use of epidural labor analgesia: a cross-sectional survey analysis.

Introduction: This study aimed to explore the personal and organizational factors influencing the lack of implementation of epidural labor analgesia (ELA). Methods: This study was conducted at the Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, China. A total of 451 women who underwent vaginal delivery without ELA between 8 October 2021 and 30 March 2022, were included. A questionnaire was used to collect the relevant data. We derived and validated the variable, without ELA, by using binary logistic regression analysis. Results: Of the total 451 included, 355 (78.7%) initially preferred ELA, whereas 96 (21.3%) rejected it directly. Five variables were validated (p < 0.05): multiparas, ELA would lead to back pain, experienced ELA in previous delivery, the inner attitude toward labor pain, and blood routine and coagulation function not being tested within 14 days. The sensitivity and specificity of this model were 96.3 and 69.8%, respectively. Conclusion: The corresponding training should be provided to the medical staff to identify women at high risk of rejecting ELA during the prenatal examination process using a questionnaire, then provide them with knowledge regarding ELA, so that ELA can benefit more mothers. Additionally, the existing organizational factor should be addressed in order to efficiently provide ELA services to mothers. Clinical trial registration: This study was registered at the Chinese Clinical Trial Registry (Chi CTR 2000034625) on July 12, 2020.

Twin Growth Discordance and Risk of Postpartum Hemorrhage: A Retrospective Cohort Study.

Background: In recent years, the incidence of postpartum hemorrhage has increased globally. Multiple pregnancies and cesarean sections are well-known risk factors for postpartum hemorrhage. No studies have evaluated the associations between fetal growth anomalies and postpartum hemorrhage in women with twin pregnancies undergoing cesarean section. This study aimed to identify the relationship between fetal growth anomalies and postpartum hemorrhage in women with twin pregnancies undergoing cesarean section. Methods: This retrospective single-center study included 3,180 women with twin pregnancies at a tertiary hospital between August 2013 and July 2020. Singleton reference charts were used to assess fetal growth restriction at birth. Discordant growth was defined as an intertwin birth weight difference of ≥20%. Logistic regression analyses were used to evaluate the association between fetal growth anomalies and postpartum hemorrhage. Additionally, sensitivity analysis of abnormal placenta and stratification by twin chorionicity were conducted. Results: The overall incidence of postpartum hemorrhage was 4.3%. Twin growth discordance, especially with fetal growth restriction, was associated with an increased risk of postpartum hemorrhage (adjusted odds ratio [AOR] = 1.62, 95% confidence interval [CI], 1.05-2.51, P = 0.031; AOR = 1.71; 95% CI, 1.08-2.70, P = 0.022; AOR = 1.98, 95% CI, 1.21-3.25, P = 0.006, respectively). After stratification, this relationship persisted in dichorionic twins (OR = 1.71, 95% CI, 1.04-2.82, P = 0.036; OR = 1.90, 95% CI, 1.13-3.21, P = 0.016; OR = 2.48, 95% CI, 1.41-4.38, P = 0.002, respectively). However, no significant association was observed in monochorionic twin pregnancies. Conclusion: Growth discordance, especially complicated by fetal growth restriction, was associated with an increased risk of postpartum hemorrhage in women with twin pregnancies undergoing cesarean section, and was more evident in patients with dichorionic twins.

Comparison of different approaches to combined spinal epidural anesthesia (CSEA) under the guidance of ultrasound in cesarean delivery of obese patients: a randomized controlled trial.

BACKGROUND: Combined spinal epidural anesthesia (CSEA) is commonly performed in cesarean deliveries. However, it is difficult to perform in obese parturients because of positioning challenges. The aim of this study was to compare the effect of different approaches to CSEA under the guidance of ultrasound. METHODS: One hundred obese patients (BMI ≥ 30 kg/m2) who underwent elective cesarean section were randomly enrolled. Patients were assigned to a median approach group and a paramedian approach group randomly. Clinical characteristics were compared between groups. First-attempt success rate, the median positioning time and total operation time, ultrasonic predicted anesthesia puncture depth, actual puncture depth, anesthesia adverse reactions, complications after anesthesia, and patients' satisfaction with the epidural puncture were recorded. RESULTS: The first-attempt success rate was significantly different between the two groups [92% (46/50) vs. 76% (38/50), P = 0.029]. The median positioning time and total operation time in the paramedian approach group were higher than those in the median approach group (227.7 s vs. 201.6 s, P = 0.037; 251.3 s vs. 247.4 s, P = 0.145). The incidence of postanesthesia complications in the paramedian approach group was significantly lower than that in the median approach group (2% vs. 12%, P = 0.026), and patient satisfaction was higher in the paramedian approach group than in the median approach group (P = 0.032). CONCLUSION: The ultrasound-guided paramedian approach for CSEA is time-consuming, but it can effectively improve the success rate of the first puncture, reduce the incidence of anesthesia-related adverse reactions, and improve patient satisfaction. TRIAL REGISTRATION: This study was registered with the Chinese Clinical Trial Registry (ChiCTR1900024722) on July 24, 2019.

Accuro ultrasound-based system with computer-aided image interpretation compared to traditional palpation technique for neuraxial anesthesia placement in obese parturients undergoing cesarean delivery: a randomized controlled trial.

PURPOSE: Recently, a new handheld ultrasound-based device, called Accuro, has been commercialized with a real-time automated interpretation of lumbar ultrasound images. We hypothesized that the handheld ultrasound device would improve the efficacy and safety of combined spinal-epidural anesthesia (CSEA) for cesarean delivery in obese parturients. METHODS: Eighty parturients with a body mass index > 30 kg∙m-2 scheduled for elective cesarean delivery were randomly allocated equally (palpation group and ultrasound group). The primary outcome was the first insertion success rate. Secondary outcomes were the time taken to identify the needle puncture site, duration of CSEA procedure, the total time, the rate of parturients who require needle redirections, the number of skin punctures, changes in the intended interspace, and the incidence of complications. RESULTS: Compared to the palpation group, the first insertion success rate was significantly higher (72.5% vs. 40.0%; P = 0.003), and time taken to identify the needle puncture site was less (30 [26-36] vs. 39 [32-49] seconds; P = 0.001) in the ultrasound group. The rate of parturients who required needle redirections (40.0% vs. 72.5%; P = 0.003) and the incidence of paresthesia were both lower (7.5% vs. 45.0%; P < 0.001). The other outcomes had no significant difference between groups. The mean difference between the epidural depth measured by the handheld ultrasound and needle depth was - 0.29 cm [95% limit of agreement, - 0.52 to - 0.05]. CONCLUSIONS: Our study suggests using the Accuro ultrasound device can enhance the efficacy and safety of CSEA in obese parturients when executed by experienced anesthesiologists, and its automated estimation of epidural depth is accurate.

Effect of Dural Puncture Epidural Technique Combined With Programmed Intermittent Epidural Bolus on Labor Analgesia Onset and Maintenance: A Randomized Controlled Trial.

BACKGROUND: The dural puncture epidural (DPE) technique is associated with faster onset than the conventional epidural (EP) technique for labor analgesia. The programmed intermittent epidural bolus (PIEB) mode for maintaining labor analgesia allows for lower anesthetic drug consumption than the continuous epidural infusion (CEI) mode. Whether DPE technique with PIEB mode offers additional benefits for analgesia onset, local anesthetic drug consumption, and side effects versus EP or DPE techniques with CEI mode remains unclear. METHODS: Nulliparous women with a visual analog scale (VAS) pain score >50 mm and cervical dilation <5 cm were randomly assigned to receive EP + CEI, DPE + CEI, or DPE + PIEB for labor analgesia. A 25-gauge needle was used for dural puncture. Analgesia was initiated with 10 mL of 0.1% ropivacaine with 0.3 µg/mL of sufentanil and maintained with the same solution at 8 mL/h in all groups. A 5-mL patient-controlled epidural analgesia (PCEA) bolus was programmed with a 20-minute lockout. Breakthrough pain not amendable by PCEA was treated with provider boluses of 5 mL of 0.125% ropivacaine. The primary outcome was "time to adequate analgesia," defined as a VAS pain score ≤30 mm during 2 consecutive contractions, and was analyzed using Kaplan-Meier curves and a Cox proportional hazard model. Secondary outcomes included the VAS scores, ropivacaine consumption, sensory block level to ice, PCEA and provider boluses intervention, mode of delivery, duration of labor, Bromage scores, Apgar scores, occurrence of side effects, and maternal satisfaction with the anesthesia. RESULTS: A total of 116 women were included (38 in the EP + CEI group, 40 in the DPE + CEI group, and 38 in the DPE + PIEB group). Adequate anesthesia was achieved faster in the DPE + CEI and DPE + PIEB groups than in the EP + CEI group (hazard ratio = 1.705; 95% confidence interval [CI], 1.039-2.800; P = .015; and hazard ratio = 1.774; 95% CI, 1.070-2.941; P = .012, respectively). DPE technique with PIEB mode was associated with the fewest PCEA boluses and the lowest hourly ropivacaine consumption (both P < .001). There were no differences in the duration of labor, mode of delivery, Bromage scores, newborn Apgar scores, incidence of side effects, and maternal satisfaction scores among the groups. CONCLUSIONS: The use of DPE technique for neuraxial analgesia was associated with faster onset than the use of the EP technique. DPE technique with PIEB mode achieved the greatest drug-sparing effect without increasing maternal or neonatal side effects.

The efficacy of high flow nasal oxygenation for maintaining maternal oxygenation during rapid sequence induction in pregnancy: A prospective randomised clinical trial.

BACKGROUND: High-flow nasal oxygenation (HFNO) for pre-oxygenation in rapid sequence induction (RSI) has only been assessed in volunteer parturients without intubation. OBJECTIVES: To evaluate the efficacy of HFNO in comparison with the conventional facemask for oxygenation during RSI for caesarean section under general anaesthesia. SETTING: Operating room in a tertiary hospital. DESIGN: Prospective randomised, controlled study. PARTICIPANTS: Thirty-four healthy parturients undergoing general anaesthesia for caesarean section. INTERVENTIONS: Parturients were randomly assigned to HFNO or standard facemask (SFM) group. MAIN OUTCOME MEASURES: The primary outcome measure was the PaO2 immediately after intubation. Secondary outcomes included lowest saturation throughout the intubation procedure, end-tidal oxygen concentration (EtO2) on commencing ventilation, blood gas analysis (pH, PaCO2), fetal outcomes and intubation-related adverse events. RESULTS: PaO2 in the HFNO group was significantly higher than that in SFM group (441.41 ±â€Š46.73 mmHg versus 328.71 ±â€Š72.80 mmHg, P < 0.0001). The EtO2 concentration in the HFNO group was higher than that in the SFM group (86.71 ±â€Š4.12% versus 76.94 ±â€Š7.74%, P < 0.0001). Compared to baseline, PaCO2 immediately after intubation also increased significantly in both groups (HFNO group: 30.87 ±â€Š2.50 mmHg versus 38.28 ±â€Š3.18 mmHg; SFM group: 29.82 ±â€Š2.57 mmHg versus 38.05 ±â€Š5.76 mmHg, P < 0.0001), but there was no difference in PaCO2 between the two groups. There was no difference in lowest saturation, intubation times, duration of apnoea, pH value or fetal outcomes. CONCLUSIONS: Compared with SFM, HFNO provided a higher PaO2 and EtO2 immediately after intubation in parturients. HFNO is safe as a method of oxygenation during RSI in parturients undergoing general anaesthesia for caesarean section. TRIAL REGISTRATION: Clinical trial ChiCTR1900023121.

Optimum interval time of programmed intermittent epidural bolus of ropivacaine 0.08% with sufentanyl 0.3 µg/mL for labor analgesia: a biased-coin up-and-down sequential allocation trial.

BACKGROUND: The programmed intermittent epidural bolus (PIEB) technique is widely used in labor analgesia, but the parameter settings of PIEB have not yet been standardized. We designed a study to identify the optimal interval duration for PIEB using 10 mL of ropivacaine 0.08% and sufentanyl 0.3 µg/mL, a regimen commonly used to control labor pain in China, to provide effective analgesia in 90% of women during the first stage of labor without breakthrough pain. METHODS: We conducted a double-blind sequential allocation trial to obtain the effective interval 90% (EI90%) during the first stage of labor between April 2019 and May 2019. This study included the American Society of Anesthesiologists physical status II-III nulliparous parturients at term, who requested epidural analgesia. The bolus volume was fixed at 10 mL of ropivacaine 0.08% with sufentanyl 0.3 µg/mL. Participants were divided into four groups (groups 60, 50, 40, and 30) according to the PIEB intervals (60, 50, 40, and 30 min, respectively). The interval duration of the first parturient was set at 60 min and that of subsequent parturients varied according to a biased-coin design. The truncated Dixon and Mood method and the isotonic regression analysis method were used to estimate the EI90% and its 95% confidence intervals (CIs). RESULTS: Forty-four women were enrolled in this study. The estimated optimal interval was 44.1 min (95% CI 41.7-46.5 min) and 39.5 min (95% CI 32.5-50.0 min), using the truncated Dixon and Mood method and isotonic regression analysis, respectively. The maximum sensory block level above T6 was in nearly 20% of parturients in group 30; however, 5.3%, 0%, and 0% of the parturients presented with sensory block level above T6 in groups 40, 50, and 60, respectively. There were no cases of hypotension and only one parturient complained of motor block. CONCLUSION: With a fixed 10 mL dose of ropivacaine 0.08% with sufentanyl 0.3 µg/mL, the optimal PIEB interval is about 42 min. Further studies are warranted to define the efficacy of this regimen throughout all stages of labor. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1900022199; http://www.chictr.org.cn/com/25/historyversionpuben.aspx?regno=ChiCTR1900022199.

Electrical Impedance Tomography-guided PEEP Titration in Patients Undergoing Laparoscopic Abdominal Surgery.

The aim of the study is to utilize electrical impedance tomography (EIT) to guide positive end-expiratory pressure (PEEP) and to optimize oxygenation in patients undergoing laparoscopic abdominal surgery.Fifty patients were randomly assigned to the control (C) group and the EIT (E) group (n = 25 each). We set the fraction of inspired oxygen (FiO2) at 0.30. The PEEP was titrated and increased in a 2-cm H2O stepwise manner, from 6 to 14 cm H2O. Hemodynamic variables, respiratory mechanics, EIT images, analysis of blood gas, and regional cerebral oxygen saturation were recorded. The postoperative pulmonary complications within the first 5 days were also observed.We chose 10 cm H2O and 8 cm H2O as the "ideal" PEEP for the C and the E groups, respectively. EIT-guided PEEP titration led to a more dorsal shift of ventilation. The PaO2/FiO2 ratio in the E group was superior to that in the C group in the pneumoperitoneum period, though the difference was not significant (330 ±â€Š10 vs 305.56 ±â€Š4 mm Hg; P = 0.09). The C group patients experienced 8.7% postoperative pulmonary complications versus 5.3% among the E group patients (relative risk 1.27, 95% confidence interval 0.31-5.3, P = 0.75).Electrical impedance tomography represents a new promising technique that could enable anesthesiologists to assess regional ventilation of the lungs and optimize global oxygenation for patients undergoing laparoscopic abdominal surgery.

Effects of sevoflurane and propofol on right ventricular function and pulmonary circulation in patients undergone esophagectomy.

OBJECT: Sevoflurane and propofol are both widely used in clinical anesthesia. The aim of this study is to compare the effects of sevoflurane and propofol on right ventricular function and pulmonary circulation in patients receiving esophagectomy. METHODS: Forty adult patients undergoing an elective open-chest thoracotomy for esophagectomy were randomized to receive either propofol (n=20) or sevoflurane (n=20) as the main anesthetic agent. The study was performed in Changzheng Hospital. Hemodynamic data were recorded at specific intervals: before the surgery (T0), BIS values reaching 40 after anesthesia induction (T1), two-lung ventilation (T2), ten minutes after one-lung ventilation (T3), the end of the operation (T4) using PiCCO2 and Swan-Ganz catheter. RESULTS: CI, RVEF, RVSWI and RVEDVI were significantly smaller in propofol group than those in sevoflurane group throughout the surgery (P<0.05). However, SVRI was significantly greater in propofol group than that in sevoflurane group (P<0.05). Compared with the patients in propofol group, the patients who received sevoflurane had a greater reduction in OI and increase in Os/Ot (P<0.05). And, PVRI was significantly smaller in sevoflurane group than in propofol group (P<0.05). CONCLUSION: Anesthesia with sevoflurane preserved better right ventricular function than propofol in patients receiving esophagectomy. However, propofol improved oxygenation and shunt fraction during one-lung ventilation compared with sevoflurane anesthesia. To have the best effect, anesthesiologists can choose the two anesthetics flexibly according to the monitoring results.

Hydrogen-rich saline attenuated neuropathic pain by reducing oxidative stress.

BACKGROUND: Reactive oxygen species (ROS) are often associated with persistent pains such as neuropathic and inflammatory pain. Hydrogen gas can reduce ROS and alleviate cerebral, myocardial, and hepatic ischemia/reperfusion injuries. In the present study, we aim to investigate whether hydrogen-rich saline can reduce neuropathic pain in a rat model of chronic constriction injury (CCI). METHODS: Thirty SD rats were randomly divided into three groups: sham group was administered sodium chloride by intrathecal injection (n=10); control groups underwent CCI surgery and were administered sodium chloride by intrathecal injection (n=10); vehicle group underwent CCI surgery and was administered hydrogen-rich saline by intrathecal injection (n=10). Drugs were administered in the dose of 100 ul/kg once a day at 0.5 hours before and 1-7 day after CCI surgery. The mechanical thresholds were tested at one day before and 3-14 day after CCI surgery. RESULTS: We found that hydrogen-rich saline significantly elevated the mechanical thresholds of neuropathic pain compared to vehicle (physiologic saline) control in CCI rats (p<0.05); it also decreased the levels of myeloperoxidase, maleic dialdehyde, and protein carbonyl in spinal cord by 7 days post-chronic constriction injury(p<0.05). In addition, hydrogen-rich saline also suppressed the expression of p38-mitogen-activated protein kinase (p38MAPK) and brain-derived neurotrophic factor (BDNF) in the spinal cord by 7 days post-chronic constriction injury (p<0.01, p<0.01, respectively), but had no effect on P2X4R (p>0.05), an ATP receptor. CONCLUSION: Intrathecal injection of hydrogen-rich saline can decrease oxidative stress and the expression of p38MAPK and BDNF that may contribute to the elevated threshold of neuropathic pain in rat CCI model.Le salin riche en hydrogène atténue la douleur névropathique en réduisant le stress oxydatif.

Role of mast cell activation in inducing microglial cells to release neurotrophin.

The brain-derived neurotrophic factor (BDNF) plays a critical role in pain hypersensitivity. BDNF is the ligand of P2X4 receptors (P2X4R) in the microglia. The causative factors involving the P2X4R over expression in the microglia remains unclear. Mast cell activation has a close relation with pain hypersensitivity. However, the underlying mechanism between mast cell activation and pain hypersensitivity is unknown. The present study aimed to elucidate the mechanism by which mast cell activation promoted the expression of P2X4R in the microglia. The results of present study showed that mast cell activation markedly promoted the expression of P2X4R and BDNF in microglial cells, which significantly enhanced the release of BDNF from microglial cells upon exposure to adenosine triphosphate. Mast cell-derived tryptase activated PAR2 that resulted in promoting the expression of P2X4R in microglial cells. Pretreatment with antibodies against tryptase or PAR2, or using tryptase-deficient HMC-1 cells or PAR2-deficient microglial cells abolished the increase in P2X4R expression and BDNF release. Increase in mitogen activated protein kinase phosphorylation was observed in the processes of mast cell-induced BDNF release and P2X4R expression. We conclude that mast cell activation has the capacity to promote the expression of P2X4R and BDNF in microglial cells.