Pre-oxygenation with high-flow oxygen through the nasopharyngeal airway compared to facemask on carbon dioxide clearance in emergency adults: a prospective randomized non-blinded clinical trial.

INTRODUCTION: Before tracheal intubation, it is essential to provide sufficient oxygen reserve for emergency patients with full stomachs. Recent studies have demonstrated that high-flow nasal oxygen (HFNO) effectively pre-oxygenates and prolongs apneic oxygenation during tracheal intubation. Despite its effectiveness, the use of HFNO remains controversial due to concerns regarding carbon dioxide clearance. The air leakage and unknown upper airway obstruction during HFNO therapy cause reduced oxygen flow above the vocal cords, possibly weaken the carbon dioxide clearance. METHODS: Patients requiring emergency surgery who had fasted < 8 h and not drunk < 2 h were randomly assigned to the high-flow group, who received 100% oxygen at 30-60 L/min through nasopharyngeal airway (NPA), or the mask group, who received 100% oxygen at 8 L/min. PaO2 and PaCO2 were measured immediately before pre-oxygenation (T0), anesthesia induction (T1), tracheal intubation (T2), and mechanical ventilation (T3). The gastric antrum's cross-sectional area (CSA) was measured using ultrasound technology at T0, T1, and T3. Details of complications, including hypoxemia, reflux, nasopharyngeal bleeding, postoperative pulmonary infection, postoperative nausea and vomiting (PONV), and postoperative nasopharyngeal pain, were recorded. The primary outcomes were PaCO2 measured at T1, T2, and T3. The secondary outcomes included PaO2 at T1, T2, and T3, CSA at T1 and T3, and complications happened during this trial. RESULTS: Pre-oxygenation was administered by high-flow oxygen through NPA (n = 58) or facemask (n = 57) to 115 patients. The mean (SD) PaCO2 was 32.3 (6.7) mmHg in the high-flow group and 34.6 (5.2) mmHg in the mask group (P = 0.045) at T1, 45.0 (5.5) mmHg and 49.4 (4.6) mmHg (P < 0.001) at T2, and 47.9 (5.1) mmHg and 52.9 (4.6) mmHg (P < 0.001) at T3, respectively. The median ([IQR] [range]) PaO2 in the high-flow and mask groups was 404.5 (329.1-458.1 [159.8-552.9]) mmHg and 358.9 (274.0-413.3 [129.0-539.1]) mmHg (P = 0.007) at T1, 343.0 (251.6-428.7 [73.9-522.1]) mmHg and 258.3 (162.5-347.5 [56.0-481.0]) mmHg (P < 0.001) at T2, and 333.5 (229.9-411.4 [60.5-492.4]) mmHg and 149.8 (87.0-246.6 [51.2-447.5]) mmHg (P < 0.001) at T3, respectively. The CSA in the high-flow and mask groups was 371.9 (287.4-557.9 [129.0-991.2]) mm2 and 386.8 (292.0-537.3 [88.3-1651.7]) mm2 at T1 (P = 0.920) and 452.6 (343.7-618.4 [161.6-988.1]) mm2 and 385.6 (306.3-562.0 [105.5-922.9]) mm2 at T3 (P = 0.173), respectively. The number (proportion) of complications in the high-flow and mask groups is shown below: hypoxemia: 1 (1.7%) vs. 9 (15.8%, P = 0.019); reflux: 0 (0%) vs. 0 (0%); nasopharyngeal bleeding: 1 (1.7%) vs. 0 (0%, P = 1.000); pulmonary infection: 4 (6.9%) vs. 3 (5.3%, P = 1.000); PONV: 4 (6.9%) vs. 4 (7.0%, P = 1.000), and nasopharyngeal pain: 0 (0%) vs. 0 (0%). CONCLUSIONS: Compared to facemasks, pre-oxygenation with high-flow oxygen through NPA offers improved carbon dioxide clearance and enhanced oxygenation prior to tracheal intubation in patients undergoing emergency surgery, while the risk of gastric inflation had not been ruled out. TRIAL REGISTRATION: This trial was registered prospectively at the Chinese Clinical Research Registry on 26/4/2022 (Registration number: ChiCTR2200059192).

The involvement of the gut microbiota in postoperative cognitive dysfunction based on integrated metagenomic and metabolomics analysis.

IMPORTANCE: As the population ages and medical technology advances, anesthesia procedures for elderly patients are becoming more common, leading to an increased prevalence of postoperative cognitive dysfunction. However, the etiology and correlation between the gut microbiota and cognitive dysfunction are poorly understood, and research in this area is limited. In this study, mice with postoperative cognitive dysfunction were found to have reduced levels of fatty acid production and anti-inflammatory flora in the gut, and Bacteroides was associated with increased depression, leading to cognitive dysfunction and depression. Furthermore, more specific microbial species were identified in the disease model, suggesting that modulation of host metabolism through gut microbes may be a potential avenue for preventing postoperative cognitive dysfunction.

Effect of intravenous vs. inhaled penehyclidine on respiratory mechanics in patients during one-lung ventilation for thoracoscopic surgery: a prospective, double-blind, randomised controlled trial.

BACKGROUND: Minimising postoperative pulmonary complications (PPCs) after thoracic surgery is of utmost importance. A major factor contributing to PPCs is the driving pressure, which is determined by the ratio of tidal volume to lung compliance. Inhalation and intravenous administration of penehyclidine can improve lung compliance during intraoperative mechanical ventilation. Therefore, our study aimed to compare the efficacy of inhaled vs. intravenous penehyclidine during one-lung ventilation (OLV) in mitigating driving pressure and mechanical power among patients undergoing thoracic surgery. METHODS: A double-blind, prospective, randomised study involving 176 patients scheduled for elective thoracic surgery was conducted. These patients were randomly divided into two groups, namely the penehyclidine inhalation group and the intravenous group before their surgery. Driving pressure was assessed at T1 (5 min after OLV), T2 (15 min after OLV), T3 (30 min after OLV), and T4 (45 min after OLV) in both groups. The primary outcome of this study was the composite measure of driving pressure during OLV. The area under the curve (AUC) of driving pressure from T1 to T4 was computed. Additionally, the secondary outcomes included mechanical power, lung compliance and the incidence of PPCs. RESULTS: All 167 participants, 83 from the intravenous group and 84 from the inhalation group, completed the trial. The AUC of driving pressure for the intravenous group was 39.50 ± 9.42, while the inhalation group showed a value of 41.50 ± 8.03 (P = 0.138). The incidence of PPCs within 7 days after surgery was 27.7% in the intravenous group and 23.8% in the inhalation group (P = 0.564). No significant differences were observed in any of the other secondary outcomes between the two groups (all P > 0.05). CONCLUSIONS: Our study found that among patients undergoing thoracoscopic surgery, no significant differences were observed in the driving pressure and mechanical power during OLV between those who received an intravenous injection of penehyclidine and those who inhaled it. Moreover, no significant difference was observed in the incidence of PPCs between the two groups.

Effect of Dexmedetomidine on Postoperative Plasma Neurofilament Light Chain in Elderly Patients Undergoing Thoracoscopic Surgery: A Prospective, Randomized Controlled Trial.

Purpose: Dexmedetomidine exerts a neuroprotective effect, however, the mechanism underlying this effect remains unclear. This study aimed to explore whether dexmedetomidine can reduce the increase in neurofilament light chain (NfL) protein concentration to play a neuroprotective role during thoracoscopic surgery. Patients and Methods: Patients aged ≥60 years undergoing general anesthesia for thoracoscopic surgery were randomly assigned to receive dexmedetomidine (group D) or not receive dexmedetomidine (group C). Patients in group D received a loading dose of dexmedetomidine 0.5 µg/kg before anesthesia induction and a continuous infusion at 0.5 µg·kg-1·h-1 until the end of the surgery. Dexmedetomidine was not administered in group C. The primary outcome was the NfL concentration on postoperative day 1. The concentrations of procalcitonin (PCT), serum amyloid A (SAA), and high-sensitivity C-reactive protein (hs-CRP) were detected preoperatively and on postoperative day 1. In addition, the numerical rating scale (NRS) and quality of recovery-40 (QoR-40) scores were evaluated. Results: A total of 38 patients in group D and 37 in group C were included in the analysis. No differences were observed between the groups in terms of the plasma concentration of NfL preoperatively and on postoperative day 1 (11.17 [8.86, 13.93] vs 13.15 [10.76, 15.56] pg/mL, P > 0.05; 16.70 [12.23, 21.15] vs 19.48 [15.25, 22.85] pg/mL, P > 0.05, respectively). However, the postoperative plasma NfL concentration was significantly higher than the preoperative value in both groups (both P < 0.001). The groups exhibited no differences in PCT, SAA, hs-CRP, NRS, and QoR-40 (all P > 0.05). Conclusion: Intraoperative administration of dexmedetomidine at a conventional dose does not appear to significantly reduce the increase in postoperative plasma NfL concentration in elderly patients undergoing thoracoscopic surgery. This finding suggests that the neuroprotective effect of dexmedetomidine at a conventional dose was not obvious during general anesthesia.

Effect of intraoperative low vs. conventional tidal volume on the incidence of postoperative acute kidney injury after noncardiac surgery: a two-center randomized clinical trial.

BACKGROUND: In adults undergoing noncardiac surgery, the correlation between intraoperative tidal volume and postoperative acute kidney injury (AKI) is unclear. This study aimed to investigate the effects of low tidal volume ventilation on the incidence of postoperative AKI compared with conventional tidal volume in adults undergoing noncardiac surgery. METHODS: This was a two-center prospective randomized controlled trial on adult patients who underwent noncardiac surgery and had a mechanical ventilation of >60 min. Patients were randomized to receive either a tidal volume of 6 mL/kg pre-predicted body weight (PBW, low tidal volume) or a tidal volume of 10 mL/kg pre-predicted body weight (conventional tidal volume). The primary outcome was the incidence of AKI after non-cardiac surgery. Appropriate statistical methods were used for this study. RESULTS: Among the 1982 randomized patients, 943 with low tidal volume and 958 with conventional tidal volume were evaluable for the primary outcome. Postoperative AKI occurred in 12 patients (1.3%) in the low tidal volume group and 11 patients (1.1%) in the conventional tidal volume group, with an odds ratio of 0.889 (95%CI, 0.391-2.03) and a relative risk of 0.999 ([95%CI, 0.989-1.01]; P=0.804). Postoperative serum creatinine levels increased in 284 (30.0%) patients with low tidal volume compared to 316 (32.0%) patients with conventional tidal volume (P=0.251). No difference in postoperative serum creatinine levels was found between the two groups (57.5 [49.0-68.2] µmol/L vs. 58.8[50.4-69.5] µmol/L, P=0.056). CONCLUSIONS: Among adults undergoing noncardiac surgery, low tidal volume mechanical ventilation did not significantly reduce the incidence of postoperative AKI compared with conventional tidal volume.

Correlation between individual physical characteristics and spinal cerebrospinal fluid volume.

Spinal cerebrospinal fluid (CSF) volume is the primary determinant for the spread of spinal anesthesia. However, it cannot generally be obtained during spinal anesthesia, and patient physical characteristics are always adopted to obtain a suitable spinal spread. In this study, we sought to explore the relationship between individual physical characteristics and thoracosacral CSF volume to provide a theoretical basis for more accurate spinal anesthesia. In total 35 healthy volunteers were enrolled in this study. Three-dimensional magnetic resonance imaging was used to reconstruct and measure the spinal CSF volume. Physical characteristics and spinal CSF volume were recorded. Bivariate and multiple linear regression analyses were used to analyze the correlation between the individual physical characteristics and thoracosacral CSF volume. Total of 31 participants were included in the final analysis. Bivariate linear correlation analysis showed that the volume of thoracosacral CSF was correlated with both individual dorso-sacral distance and height (both p < 0.01), but not with abdominal girth (p > 0.05). Multiple linear regression analyses revealed that the adjusted R2 values were 0.404 for the regression equation between thoracosacral CSF volume, dorso-sacral distance, and abdominal girth. Our study showed that dorso-sacral distance and abdominal girth were essential factors contributing to thoracosacral CSF volume. A longer dorso-sacral distance and smaller abdominal girth mean larger spinal CSF volume.

Standard opioid-containing versus opioid-sparing anesthesia on early postoperative recovery after video-assisted thoracic surgery: A propensity-weighted analysis.

Purpose: Opioids have several adverse effects. At present, there are no large clinical studies on the effects of opioid-sparing anesthesia on early postoperative recovery after thoracoscopic surgery. This study was to investigate the effects of opioid-sparing anesthesia on early postoperative recovery after thoracoscopic surgery. Methods: Adult patients who underwent video-assisted thoracic surgery from 1 January 2019 to 28 February 2021 were enrolled by reviewing the electronic medical records. Participants were divided into opioid-sparing anesthesia (OSA group) and opioid-containing anesthesia (STD group) based on intraoperative opioid usage. The propensity-score analysis was to compare the early postoperative recovery of two groups. The outcome measurements included the incidence of postoperative nausea and vomiting (PONV) during an entire hospital stay, need for rescue antiemetic medication, postoperative-pain episodes within 48 h after surgery, need for rescue analgesia 48 h postoperatively, duration of postoperative hospital stay, length of PACU stay, postoperative fever, postoperative shivering, postoperative atrial fibrillation, postoperative pulmonary infection, postoperative hypoalbuminemia, postoperative hypoxemia, intraoperative blood loss, and intraoperative urine output. Results: A total of 1,975 patients were identified. No significant difference was observed in patient characteristics between the OSA and STD groups after adjusting for propensity score-based inverse probability treatment weighting. The incidence of postoperative nausea and vomiting was significantly lower in the OSA group than in the STD group (14.7% vs. 18.9%, p = 0.041). The rescue antiemetic use rate was lower in the OSA group than in the STD group (7.5% vs.12.2%; p = 0.002). PACU duration was longer in the OSA group than in the STD group (70.8 ± 29.0 min vs. 67.3 ± 22.7 min; p = 0.016). The incidence of postoperative fever was higher in the STD group than that in the OSA group (11.0% vs.7.7%; p = 0.032). There were no differences between the groups in terms of other outcomes. Conclusions: Our results suggest that opioid-sparing anesthesia has a lower incidence of postoperative complications than opioid-based anesthetic techniques.

CT-guided radiofrequency ablation of the extracranial cranial nerve for the treatment of Meige's syndrome.

Background: Meige' s syndrome, a rare form of dystonia, lacks effective treatment. The purpose of this study was to determine the effects of CT-guided percutaneous extracranial radiofrequency ablation of the facial and/or trigeminal nerves in the treatment of Meige's syndrome. Methods: A total of 10 patients were enrolled in this study, with the numbers of blepharospasm dystonia syndrome (BDS), oromandibular dystonia syndrome (ODS), and blepharospasm combined with oromandibular dystonia syndrome (B-ODS) being 7, 1, and 2, respectively. BDS patients underwent radiofrequency ablation of the bilateral stylomastoid foramen facial nerve; ODS patients underwent radiofrequency ablation of the bilateral foramen oval trigeminal mandibular branch, and B-ODS patients underwent radiofrequency ablation of the bilateral stylomastoid foramen facial nerve and foramen oval trigeminal mandibular branch. The therapeutic effects and complications were observed. Results: All 10 patients in this series experienced improved Meige's syndrome-related symptoms after extracranial radiofrequency ablation of the cranial and/or mandibular branches of the extracranial trigeminal nerve. Adverse events included class II-III facial paralysis and/or mandibular skin numbness. Two patients had recurrences at the 18th and 22nd months postoperatively, respectively; the other patients were being followed up. Conclusion: These results shown that CT-guided radiofrequency ablation of bilateral stylomastoid foramen facial nerve and/or oval foramen trigeminal mandibular branch can effectively treat the corresponding types of Meige's syndrome. According to preliminary observations, the therapeutic effect may last more than 18 months.

Inferior Vena Cava Collapsibility Index Can Predict Hypotension and Guide Fluid Management After Spinal Anesthesia.

PURPOSE: We hypothesized that inferior vena cava collapsibility index (IVCCI)-guided fluid management would reduce the incidence of postspinal anesthesia hypotension in patients undergoing non-cardiovascular, non-obstetric surgery. METHODS: A receiver operating characteristic (ROC) curve was used to determine the diagnostic value of IVCCI for predicting hypotension after induction of spinal anesthesia and calculate the cut-off value. Based on the cut-off variation value, the following prospective randomized controlled trial aimed to compare the incidence of postspinal anesthesia hypotension between the IVCCI-guided fluid administration group and the standard fluid administration group. Secondary outcomes included the rate of vasoactive drug administration, the amount of fluid administered, and the incidence of nausea and vomiting. RESULTS: ROC curve analysis revealed that IVCCI had a sensitivity of 83.9%, a specificity of 76.3%, and a positive predictive value of 84% for predicting postspinal anesthesia hypotension at a cut-off point of >42%. The area under the curve (AUC) was 0.834 (95% confidence interval: 0.740-0.904). According to the cut-off variation value of 42%, the IVCCI-guided group exhibited a lower incidence of hypotension than the standard group [9 (15.3%) vs. 20 (31.7%), P = 0.032]. Total fluid administered was lower in the IVCCI-guided group than in the standard group [330 (0-560) mL vs. 345 (285-670) mL, P = 0.030]. CONCLUSIONS: Prespinal ultrasound scanning of the IVCCI provides a reliable predictor of hypotension following spinal anesthesia at a cut-off point of >42%. IVCCI-guided fluid management before spinal anesthesia can reduce the incidence of hypotension following spinal anesthesia.

Continuous Rhomboid Intercostal Block for Thoracoscopic Postoperative Analgesia.

BACKGROUND: Rhomboid intercostal block is a type of plane block used for postoperative analgesia after video-assisted thoracoscopic surgery. This prospective randomized controlled trial was conducted to investigate the effects of ultrasound-guided continuous rhomboid intercostal block (CRIB) on the global Quality of Recovery (QoR-40) scores and postoperative analgesia after video-assisted thoracoscopic surgery. METHODS: A total of 66 adult patients scheduled for elective unilateral video-assisted thoracoscopic surgery were randomly allocated to group C and group CRIB. In group C, patients were administered patient-controlled intravenous analgesia with sufentanil after operation. Patients in group CRIB received patient-controlled analgesia with ropivacaine CRIB. All patients completed the QoR-40 test during the preoperative evaluation and again 24 hours after the operation. Information on 48-hour postoperative pain and adverse events was recorded. RESULTS: The QoR-40 scores of group C were significantly lower than the scores of group CRIB (155.4 ± 6.1 vs 172.6 ± 6.3; P < .001), with a mean difference of -17.2 (95% CI, -20.4 to -13.9) 24 hours after operation. The postoperative numeric rating scale scores in group CRIB at 6, 12, 18, and 24 hours after the surgical procedure, when patients were at rest, were significantly lower than the scores in group C (all P < .05). The postoperative numeric rating scale scores in group CRIB at 1, 3, 6, 12, 18, 24, and 36 hours after surgical procedure, when patients were moving, were significantly lower than the scores in group C (all P < .05). CONCLUSIONS: In patients who underwent video-assisted thoracoscopic surgery, CRIB led to improved quality of recovery and postoperative analgesia.

Opioid-free anesthesia for postoperative recovery after video-assisted thoracic surgery: A prospective, randomized controlled trial.

Purpose: Opioid-based anesthesia is a traditional form of anesthesia that has a significant analgesic effect; however, it can cause nausea, vomiting, delirium, and other side effects. Opioid-free anesthesia with dexmedetomidine and lidocaine has attracted widespread attention. This study aimed to compare the effects of opioid-free and opioid-based anesthesia (OFA and OBA, respectively) on postoperative recovery in patients who had undergone video-assisted thoracic surgery. Methods: Eighty patients undergoing video-assisted thoracic surgery were assigned to receive either opioid-free anesthesia (OFA group) or opioid-based anesthesia (OBA group) according to random grouping. The primary outcome of the study was the quality of recovery-40 scores (QoR-40) 24 h postoperatively. The secondary outcome measure was numerical rating scale (NRS) scores at different times 48 h postoperatively. In addition to these measurements, other related parameters were recorded. Results: Patients who received opioid-free anesthesia had higher QoR-40 scores (169.1 ± 5.1 vs. 166.8 ± 4.4, p = 0.034), and the differences were mainly reflected in their comfort and emotional state; however, the difference between the two groups was less than the minimal clinically important difference of 6.3. We also found that the NRS scores were lower in the OFA group than in the OBA group at 0.5 h (both p < 0.05) and 1 h (both p < 0.05) postoperatively and the cumulative 0-24 h postoperative dosage of sufentanil in the OBA group was higher than that in the OFA group (p = 0.030). There were no significant differences in postoperative nausea and vomiting (PONV) (p = 0.159). No surgical or block complications were observed between the groups. Conclusion: Opioid-free analgesia potentially increased the postoperative recovery in patients who underwent video-assisted thoracic surgery. Trial registration: The study protocol was registered in the Chinese Clinical Trial Register under the number ChiCTR2100045344 (http://www.chictr.org.cn/showproj.aspx?proj=125033) on April 13, 2021.

Amelioratory Effect of Melatonin on Cognition Dysfunction Induced by Sevoflurane Anesthesia in Aged Mice.

Background: Postoperative cognitive dysfunction (POCD) can be described as a clinical phenomenon characterized by cognitive impairment in patients, particularly elderly patients, after anesthesia and surgery. Researchers have focused on the probable effect of general anesthesia drugs on cognitive functioning status in older adults. Melatonin is an indole-type neuroendocrine hormone with broad biological activity and potent anti-inflammatory, anti-apoptotic, and neuroprotective effects. This study investigated the effects of melatonin on cognitive behavior in aged mice anesthetized with sevoflurane. In addition, melatonin's molecular mechanism was determined. Objectives: This study aimed to investigate the mechanisms of melatonin against sevoflurane-induced neurotoxicity. Methods: A total of 94 aged C57BL/6J mice were categorized into different groups, namely control (control + melatonin (10 mg/kg)), sevoflurane (sevoflurane + melatonin (10 mg/kg)), sevoflurane + melatonin (10 mg/kg) + phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) inhibitor LY294002 (30 mg/kg), and sevoflurane + melatonin (10 mg/kg) + mammalian target of rapamycin (mTOR) inhibitor (10 mg/kg). The open field and Morris water maze tests were utilized to assess the neuroprotective effects of melatonin on sevoflurane-induced cognitive impairment in aged mice. The expression levels of the apoptosis-linked proteins, PI3K/Akt/mTOR signaling pathway, and pro-inflammatory cytokines in the brain's hippocampus region were determined using the Western blotting technique. The apoptosis of the hippocampal neurons was observed using the hematoxylin and eosin staining technique. Results: Neurological deficits in aged, sevoflurane-exposed mice were significantly decreased after melatonin treatment. Mechanistically, melatonin treatment restored sevoflurane-induced down-regulated PI3K/Akt/mTOR expression and significantly attenuated sevoflurane-induced apoptotic cells and neuroinflammation. Conclusions: The findings of this study have highlighted the neuroprotective effect of melatonin on sevoflurane-induced cognitive impairment via regulating the PI3K/Akt/mTOR pathway, which might be effective in the clinical treatment of elderly patients with anesthesia-induced POCD.

Evaluation of radial and ulnar artery blood flow after radial artery decannulation using colour Doppler ultrasound.

BACKGROUND: There is a lack of reports in the literature regarding changes in radial artery blood flow after decannulation. The objective of this study was to investigate changes in radial and ulnar artery blood flow after radial artery decannulation using Doppler ultrasound and to explore the factors that influence radial artery blood flow recovery. METHODS: In current observational study, we used colour Doppler ultrasound to measure the cross-sectional area of the radial (SR) and ulnar artery (SU) and peak systolic velocity of the radial (PSVR) and ulnar artery (PSVU) for both hands at four time points in patients with radial artery cannulation: pre-cannulation (T0), 30 min after decannulation (T1), 24 h after decannulation (T2), and 7 days after decannulation (T3). Repeated measures analysis of variance and logistic regression analysis were performed to analyse the data. RESULTS: Overall, 120 patients were included in the present study. We obtained the following results on the side ipsilateral to the cannulation: compared with T0, the ratio of PSVU/PSVR increased significantly at T1 and T2 (p < 0.01); compared with T1, the ratio of PSVU/PSVR decreased significantly at T2 and T3 (p < 0.01); compared with T2, the ratio of PSVU/PSVR decreased significantly at T3 (p < 0.01). Female sex (OR, 2.76; 95% CI, 1.01-7.57; p = 0.048) and local hematoma (OR 3.04 [1.12-8.25]; p = 0.029) were factors that were significantly associated with the recovery of radial artery blood flow 7 days after decannulation. CONCLUSIONS: There was a compensatory increase in blood flow in the ulnar artery after ipsilateral radial artery decannulation. Female sex and local hematoma formation are factors that may affect the recovery of radial artery blood flow 7 days after catheter removal.

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.

Rhomboid intercostal block combined with sub-serratus plane block versus rhomboid intercostal block for postoperative analgesia after video-assisted thoracoscopic surgery: a prospective randomized-controlled trial.

BACKGROUND: Rhomboid intercostal block (RIB) and Rhomboid intercostal block with sub-serratus plane block (RISS) are the two types of plane blocks used for postoperative analgesia after video-assisted thoracoscopic surgery (VATS). This prospective randomized controlled trial was performed to analyze the postoperative analgesic effects of ultrasound-guided RIB block and RISS block after video-assisted thoracoscopic surgery. METHODS: Ninety patients aged between 18 and 80 years, with American Society of Anesthesiologists physical status Classes I-II and scheduled for elective unilateral VATS were randomly allocated into three groups. In group C, no block intervention was performed. Patients in group RIB received ultrasound-guided RIB with 20-mL 0.375% ropivacaine and those in group RISS received ultrasound-guided RIB and serratus plane block using a total of 40-mL 0.375% ropivacaine. All patients received intravenous sufentanil patient-controlled analgesia upon arrival in the recovery room. Postoperative sufentanil consumption and pain scores were compared among the groups. RESULTS: The dosages of sufentanil consumption at 24 h after the surgery in the RIB and RISS groups were significantly lower than that in group C (p < 0.001 and p < 0.001 for all comparisons, respectively), the postoperative Numerical Rating Scale (NRS) scores in the RIB and RISS groups at 0.5, 1, 3, 6, 12, 18, and 24 h after surgery when patients were at rest or active were significantly lower than that in group C (p < 0.05 for all comparisons). The required dosage of sufentanil and time to first postoperative analgesic request in groupRISS were less than those in the group RIB at 24 h after the surgery (p < 0.001 and p < 0.001 for all comparisons, respectively). Similarly, the Numerical Rating Scale scores for group RISS at 12, 18, and 24 h after the surgery when the patients were active were significantly lower than those for group RIB (p < 0.05 for all comparisons). CONCLUSION: Both ultrasound-guided RIB block and RISS block can effectively reduce the demand for sufentanil within 24 h after VATS, and less sufentanil dosage is needed in patient with RISS block. Ultrasound-guided RIB block and RISS block can effectively relieve pain within 24 h after VATS, and RISS block is more effective.

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).

Effects of combined warmed preoperative forced-air and warmed perioperative intravenous fluids on maternal temperature during cesarean section: a prospective, randomized, controlled clinical trial.

BACKGROUND: Preventing the frequent perioperative hypothermia incidents that occur during elective caesarean deliveries would be beneficial. This trial aimed at evaluating the effect of preoperative forced-air warming alongside perioperative intravenous fluid warming in women undergoing cesarean sections under spinal anesthesia. METHODS: We randomly allocated 135 women undergoing elective cesarean deliveries to either the intervention group (preoperative forced-air and intravenous fluid warming, n = 69) or the control group (no active warming, n = 66). The primary outcome measure was the core temperature change between groups from baseline to the end of the surgical procedure. Secondary outcomes included thermal comfort scores, the incidences of shivering and hypothermia (< 36 °C), the core temperature on arrival at the post-anesthesia care unit, neonatal axillary temperature at birth, and Apgar scores. RESULTS: Two-way repeated measures ANOVA revealed significantly different core temperature changes (from the pre-spinal temperature to that at the end of the procedure) between groups (F = 13.022, P < 0.001). The thermal comfort scores were also higher in the intervention group than in the control group (F = 9.847, P = 0.002). The overall incidence of perioperative hypothermia was significantly lower in the intervention group than in the control group (20.6% vs. 51.6%, P < 0.0001). CONCLUSIONS: Warming preoperative forced-air and perioperative intravenous fluids may prevent maternal hypothermia, reduce maternal shivering, and improve maternal thermal comfort for patients undergoing cesarean sections under spinal anesthesia. TRIAL REGISTRATION: The study was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR1800019117) on October26, 2018.

Additional femoral nerve block analgesia does not reduce the chronic pain after total knee arthroplasty: A retrospective study in patients with knee osteoarthritis.

Femoral nerve block analgesia was deemed to the gold standard for acute pain management after total knee arthroplasty (TKA). But effect on chronic pain management is not investigated fully. We conducted a retrospective study to explore the effect of single-injection femoral nerve block on postsurgical chronic pain.All medical records of patients undertaking TKA between January, 2013 and June, 2014 were reviewed via the Docare anesthesia database. Patients who administrated with the self-controlled intravenous analgesia were assigned to group P. Patients who received a single-injection femoral never block combined with patient self-controlled intravenous analgesia were assigned to group N + P. The visual analog scale (VAS) score before surgery, the first postoperative day (POD 1), POD 2, 3 months, 6 months, and 12 months after surgery were extracted from medical records. Pain score was compared over these 2 groups to investigate treatment outcomes.In all, 470 patients met the selection criteria for group P and 266 patients met the selection criteria for group N + P. Compared with group P, the VAS score decreased significantly in group N + P at POD 1 (P < .001), and the same was observed at POD 2 (P < .001); the moderate to severe pain incidence rate decreased significantly in group N + P at POD 1 (P < .01) and POD 2 (motion, P < .001). The rescued anesthesia rate reduced significantly in group N + P in POD 1 (P = .001), whereas no difference was found in POD 2 (P = .864). No difference was found at 3, 6, and 12 months after surgery (all P > .05).The single-injection femoral nerve block could relieve the acute postsurgical pain in a short period of time. But no evidence was found that it could reduce the chronic pain between 3 and 12 months after TKA.

Grip strength can be used to evaluate postoperative residual neuromuscular block recovery in patients undergoing general anesthesia.

BACKGROUND: Residual postoperative neuromuscular blockade is an important clinical issue. Neuromuscular monitoring is usually used to evaluate neuromuscular recovery in patients undergoing general anesthesia. However, this procedure is inconvenient and not widely adopted. We aimed to examine the correlation between grip strength and train-of-four ratio (TOFr) to examine whether assessing grip strength can be used clinically to monitor residual neuromuscular blockade. METHODS: One hundred twenty patients with ASA I or II scheduled for laparoscopic cholecystectomy under general anesthesia were enrolled in this study. All patients were randomly selected to receive standard anesthesia induction with either 0.6 mg·kg rocuronium or 0.2 mg·kg cisatracurium. Grip strength was tested in all patients using an electronic device before anesthesia and when TOFr values of 0.7, 0.8, and 0.9, and an hour later of TOFr value of 0.25. The time required for a change in TOFr values from 0.25 to 0.75 and 0.9 was evaluated. Spearman rank correlation analysis was performed to determine correlations between grip strength and TOFr. RESULTS: Spearman rank correlation analysis indicated that there was a significant correlation between grip strength and TOFr during patient recovery from general anesthesia (correlation coefficient for grip strength recovery [rs] = 0.886). Subgroup analysis revealed that there were no differences in mean maximum grip value recovery between patients treated with rocuronium and those treated with cisatracurium when TOFr was 0.7, 0.8, and 0.9 or when the TOFr was 0.25 after 60 minutes (all P >.05). Recovery of TOFr from 0.25 to 0.75 and from 0.25 to 0.9 was longer in patients treated with rocuronium than in those treated with cisatracurium (both P <.001). CONCLUSION: There was a strong correlation between grip strength and TOFr during recovery from general anesthesia. Evaluation of grip strength can be used as an additional strategy to evaluate postoperative residual neuromuscular blockade.

Intra-abdominal pressure, vertebral column length, and spread of spinal anesthesia in parturients undergoing cesarean section: An observational study.

BACKGROUND: In parturients with increased physiologically intra-abdominal pressure (IAP) and a short stature, a greater cephalad spread of spinal anesthesia is often observed after a fixed amount of plain bupivacaine is administered. Therefore, we designed this prospective study to test whether IAP and vertebral column length (VCL) were predictors of spinal spread in parturients undergoing a cesarean section. METHODS: A total of 113 parturients, all undergoing elective cesarean sections with single-shot spinal anesthesia, were enrolled. The L3-L4 interspace was entered, and 2 mL of 0.5% plain bupivacaine was injected into the subarachnoid space. Upon loss of temperature sensation at the T4 level, IAP was measured through a bladder catheter while the patient was in the supine position with a 10°left lateral tilt. Parturient demographic variables, including age, height, weight, IAP, and VCL were recorded. Linear regressions and multiple regressions were performed to analyze the relationships between parturient variables and the spread of spinal anesthesia. RESULTS: A total of 109 parturients were included in the analysis. Linear regression analysis showed a significant univariate correlation of height, weight, body mass index (BMI), IAP, and VCL with cephalad spread (all P< 0.004). Multiple linear regression analysis showed that IAP and VCL were the key determinants of spinal spread (both P < 0.0001), where as exclusion of age, weight, and height did not change the result (all P> 0.209). CONCLUSIONS: Our data indicated that IAP and VCL were significant predictors of intrathecal spread of plain bupivacaine, and there was a positive association between IAP and abdominal girth in term parturients.