Search

Abstract Background Adequate preoperative evaluation of the post-intubation hemodynamic instability (PIHI) is crucial for accurate risk assessment and efficient anesthesia management. However, the incorporation of this evaluation within a predictive framework have been insufficiently addressed and executed. This study aims to developed a machine learning approach for preoperatively and precisely predicting the PIHI index values. Methods In this retrospective study, the valid features were collected from 23,305 adult surgical patients at Peking Union Medical College Hospital between 2012 and 2020. Three hemodynamic response sequences including systolic pressure, diastolic pressure and heart rate, were utilized to design the post-intubation hemodynamic instability (PIHI) index by computing the integrated coefficient of variation (ICV) values. Different types of machine learning models were constructed to predict the ICV values, leveraging preoperative patient information and initiatory drug infusion. The models were trained and cross-validated based on balanced data using the SMOTETomek technique, and their performance was evaluated according to the mean absolute error (MAE), root mean square error (RMSE), mean absolute percentage error (MAPE) and R-squared index (R2). Results The ICV values were proved to be consistent with the anesthetists’ ratings with Spearman correlation coefficient of 0.877 (P

Abstract Patients with lymphangioleiomyomatosis (LAM) are considered high risk for most surgeries and require specific anesthetic considerations mainly because of the common spontaneous pneumothorax (PTX). To explore whether intraoperative mechanical ventilation could increase the risk of PTX in those patients, we included 12 surgical patients with LAM in this study, of whom four (33.3%) experienced postoperative PTX. According to our results, patients with higher CT grade, poorer pulmonary function, and a history of preoperative PTX might be more likely to develop postoperative PTX. However, intraoperative mechanical ventilation did not show obvious influence, which might help clinicians reconsider the perioperative management of LAM patients.

Abstract Background Rett Syndrome (RTT) is a rare, severe, and progressive developmental disorder with intellectual disability. Anesthesia in RTT patients presents a range of challenges. We report a child with RTT who received dental treatment under muscle relaxant-free general anesthesia in our ambulatory center. Case presentation A 15-year-old girl with RTT was admitted to our dental clinic with multiple dental caries and residual roots. Dental treatment was scheduled under ambulatory general anesthesia. After anesthesia induction, a nasal tube was initiated under the guidance of a fiberoptic bronchoscope. Multimodal analgesia, body temperature monitoring, and postoperative nausea and vomiting prevention were applied. No muscle relaxants were used throughout the process. The endotracheal tube was successfully removed after the operation and the patient was discharged home the same day. Conclusion An individualized anesthesia strategy enabled a quick and safe recovery for this RTT patient after dental treatment under muscle relaxant-free general anesthesia.

Abstract Background Retroperitoneal leiomyomas are rare, with just over 100 cases reported in the literature. Perioperative management of retroperitoneal leiomyomas can be challenging due to the large tumor size and the risk of hemorrhage. Case presentation We report a case of a 40-year-old Han woman with a 40-cm retroperitoneal leiomyoma. General anesthesia was performed for the surgical resection. Key flow parameters like cardiac output and stroke volume variation, as shown by the Vigileo™-FloTrac™ system, enabled the anesthesiologist to implement goal-directed fluid optimization. Acute normovolemic hemodilution and cell salvage technique were used resulting in a successful en bloc tumor resection with a 6000-mL estimated blood loss. Although the patient experienced postoperative bowel obstruction, no other significant complications were observed. Conclusion Advanced hemodynamic monitoring and modern patient blood management strategies are particularly helpful for anesthetic management of huge retroperitoneal leiomyomas.

Abstract Introduction Migraine, a prevalent headache disorder with unclear mechanisms and limited treatments, may be influenced by dyslipidemia and genetic factors. Statins and emerging lipid-modifying agents show potential but lack evidence for migraine management. Mendelian Randomization analysis offers insights into causal relationships and therapeutic targets. This study aims to explore genetically predicted lipid traits, drug targets, and their association with migraine risk. Method We conducted Mendelian randomization (MR) analyses utilizing genetic variants associated with lipid traits and variants in genes encoding the protein targets of various classes of lipid-lowering drugs. The specific drug classes investigated included HMGCR, PCSK9, NPC1L1, ABCG5/ABCG8, LDLR, LPL, ANGPTL3, APOB, CETP, and APOC3. To determine the effects on migraine risk, we meta-analyzed MR estimates for regional variants using data from two large sample sets. The genetic variants were weighted based on their associations with specific lipid traits, such as low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), Apolipoprotein A1, and Apolipoprotein B. To obtain association weights, we utilized data from lipid genetics consortia. For lipid-modifying drug targets that exhibited suggestive significance, we further employed expression quantitative trait locus (eQTL) data. Additionally, we performed colocalization analysis to assess genetic confounding. Result The use of genetic proxies for HMGCR inhibition demonstrated a significant association with a decreased risk of migraine in the FinnGen dataset (OR = 0.64, 95% CI: 0.46–0.88, p = 0.0006) and a nearly significant association in the Choquet dataset (OR = 0.78, 95% CI: 0.60–1.01, p = 0.06). When pooling the estimates, the overall effect size showed a reduced risk of migraine (OR = 0.73, 95% CI: 0.60–0.89, p = 0.0016). Similarly, genetic mimicry of LPL enhancement was associated with a lower risk of migraine in the FinnGen dataset (OR = 0.82, 95% CI: 0.69–0.96, p = 0.01) and the Choquet dataset (OR = 0.91, 95% CI: 0.83–0.99, p = 0.03). Pooling the estimates showed a consistent effect size (OR = 0.89, 95% CI: 0.83–0.96, p = 0.002). Sensitivity analyses yielded no statistically significant evidence of bias arising from pleiotropy or genetic confounding. Conclusion In the study, it was observed that among the 10 lipid-lowering drug targets investigated, LPL and HMGCR showed significant associations with migraine risk. These findings indicate that LPL and HMGCR have the potential to serve as candidate drug targets for the treatment or prevention of migraines.

Abstract Background Perioperative acute kidney injury (AKI) has been one of the leading causes of morbidity and mortality for surgical patients. Pheochromocytoma is a rare, catecholamine-secreting neuroendocrine neoplasm characterized by typical long-term hypertension that needs surgical resection. Our objective was to determine whether intraoperative mean arterial pressures (MAPs) less than 65 mmHg are associated with postoperative AKI after elective adrenalectomy in patients with pheochromocytoma. Methods We performed a retrospective review of patients undergoing adrenalectomy for pheochromocytoma between 1991 and 2019 at Peking Union Medical College Hospital, Beijing, China. Two intraoperative phases, before and after tumor resection, were recognized based on distinctly different hemodynamic characteristics. The authors evaluated the association between AKI and each blood pressure exposure in these two phases. The association between the time spent under different absolute and relative MAP thresholds and AKI was then evaluated adjusting for potential confounding variables. Results We enrolled 560 cases with 48 patients who developed AKI postoperatively. The baseline and intraoperative characteristics were similar in both groups. Though time-weighted average MAP was not associated with postoperative AKI during the whole operation (OR 1.38; 95% CI, 0.95–2.00; P = 0.087) and before tumor resection phase (OR 0.83; 95% CI, 0.65–1.05; P = 0.12), both time-weighted MAP and time-weighted percentage changes from baseline were strongly associated with postoperative AKI after tumor resection, with OR 3.50, 95% CI (2.25, 5.46) and 2.03, 95% CI (1.56, 2.66) in the univariable logistic analysis respectively, and with OR 2.36, 95% CI (1.46, 3.80) and 1.63, 95% CI (1.23, 2.17) after adjusting sex, surgical type (open vs. laparoscopic) and estimated blood loss in the multiple logistic analysis. At any thresholds of MAP less than 85, 80, 75, 70, and 65 mmHg, prolonged exposure was associated with increased odds of AKI. Conclusions We found a significant association between hypotension and postoperative AKI in patients with pheochromocytoma undergoing adrenalectomy in the period after tumor resection. Optimizing hemodynamics, especially blood pressure after the adrenal vessel ligation and tumor is resected, is crucial for the prevention of postoperative AKI in patient with pheochromocytoma, which could be different from general populations.

Abstract Background Whole lung lavage (WLL) has been recognized as the most effective therapy of severe pulmonary alveolar proteinosis (PAP). Most centers perform the lavage of each lung in two sessions under general anesthesia at an interval of several days to weeks. Compared with two-session WLL, one-session bilateral sequential WLL only requires general anesthesia once. However, the safety of one-session WLL in PAP patients has not been assessed by large cohort studies. In this study, we aimed to investigate the association between the mode of WLL procedure (one-session or two-session) and the risk of periprocedural complications in PAP patients. Methods In this single-center retrospective cohort study, we included adult patients who were diagnosed as PAP and had undergone WLL procedures under general anesthesia from 2000 to 2022. Patients requiring extra-corporeal oxygenation during WLL were excluded. Since some patients received multiple WLL procedures, we considered each procedure in one-session or two-session group as a unique unit in our analysis. The primary outcome was the occurrence of any complications during hospitalization, including termination of WLL procedure due to fluid leakage or refractory hypoxemia, bronchospasm, delayed endotracheal extubation, cardiovascular event, pneumothorax, and fever. Results We included a total of 175 WLL procedures (118 patients), with 48 in the two-session group and 127 in the one-session group. Periprocedural complications occurred in 17 (35.4%) and 39 (30.7%) procedures in the two-session and the one-session groups, respectively. The risk of periprocedural complications did not differ significantly between groups, after adjusting the unbalanced confounders in a multivariable model (odds ratio 0.95, 95% confidence interval 0.34 to 2.69, P 0.929) or by inverse probability of treatment weighting (odds ratio 0.70, 95% confidence interval 0.30 to 1.54, P 0.379). Compared with the two-session WLL group, the one-session WLL group had a shorter postprocedural length of hospitalization and comparable decrease in alveolar-arterial oxygen tension gradient from baseline. Conclusions One-session bilateral WLL was not associated with an increased risk of periprocedural complications compared with two-session WLL in PAP patients. Experienced physicians may consider performing one-session WLL in view of the comparable safety and efficacy and potential advantages of saving time.

Abstract Background Prehabilitation has been shown to have a positive effect on the postoperative recovery of functional capacity in patients undergoing video-assisted thoracoscopic surgery (VATS) lobectomy. The optimal way to implement prehabilitation programs, such as the optimal forms of prehabilitation, duration, intensity, and methods to improve compliance, remained to be studied. This Prehabilitation for Thoracic Surgery Study will compare the effectiveness of multimodal and aerobic training-only programs in patients undergoing thoracoscopic lobectomy. Methods This randomized pragmatic trial will be conducted in Peking Union Medical College Hospital (PUMCH) and include 100 patients who are eligible to undergo VATS lobectomy. Patients will be randomized to a multimodal or aerobic training group. Prehabilitation training guidance will be provided by a multidisciplinary care team. The patients in the multimodal group will perform aerobic exercises, resistance exercises, breathing exercises, psychological improvement strategies, and nutritional supplementation. Meanwhile, the patients in the aerobic group will conduct only aerobic exercises. The interventions will be home-based and supervised by medical providers. The patients will be followed up until 30 days after surgery to investigate whether the multimodal prehabilitation program differs from the aerobic training program in terms of the magnitude of improvement in functional capability pre- to postoperatively. The primary outcome will be the perioperative 6-min walk distance (6MWD). The secondary outcomes will include the postoperative pulmonary functional recovery status, health-related quality of life score, incidence of postoperative complications, and clinical outcomes. Discussion Prehabilitation remains a relatively new approach that is not widely performed by thoracic surgery patients. The existing studies mainly focus on unimodal interventions. While multimodal prehabilitation strategies have been shown to be preferable to unimodal strategies in a few studies, the evidence remains scarce for thoracic surgery patients. The results of this study will contribute to the understanding of methods for thoracoscopic lobectomy patients. Trial registration ClinicalTrials.gov NCT04049942 . Registered on August 8, 2019.

Abstract Background Numerous observational studies have revealed an increased risk of death and complications with transfusion, but this observation has not been confirmed in randomized controlled trials (RCTs). The “transfusion kills patients” paradox persists in real-world observational studies despite application of analytic methods such as propensity-score matching. We propose a new design to address this long-term existing issue, which if left unresolved, will be deleterious to the healthy generation of evidence that supports optimized transfusion practice. Methods In the new design, we stress three aspects for reconciling observational studies and RCTs on transfusion safety: (1) re-definition of the study population according to a stable hemoglobin range (gray zone of transfusion decision; 7.5–9.5 g/dL in this study); (2) selection of comparison groups according to a trigger value (last hemoglobin measurement before transfusion; nadir during hospital stay for control); (3) dealing with patient heterogeneity according to standardized mean difference (SMD) values. We applied the new design to hospitalized older patients (aged ≥60 years) undergoing general surgery at four academic/teaching hospitals. Four datasets were analyzed: a base population before (Base Match−) and after (Base Match+) propensity-score matching to simulate previous observational studies; a study population before (Study Match−) and after (Study Match+) propensity-score matching to demonstrate effects of our design. Results Of 6141 older patients, 662 (10.78%) were transfused and showed high heterogeneity compared with those not receiving transfusion, particularly regarding preoperative hemoglobin (mean: 11.0 vs. 13.5 g/dL) and intraoperative bleeding (≥500 mL: 37.9% vs. 2.1%). Patient heterogeneity was reduced with the new design; SMD of the two variables was reduced from approximately 100% (Base Match−) to 0% (Study Match+). Transfusion was related to a higher risk of death and complications in Base Match− (odds ratio [OR], 95% confidence interval [CI]: 2.68, 1.86–3.86) and Base Match+ (2.24, 1.43–3.49), but not in Study Match− (0.77, 0.32–1.86) or Study Match+ (0.66, 0.23–1.89). Conclusions We show how choice of study population and analysis could affect real-world study findings. Our results following the new design are in accordance with relevant RCTs, highlighting its value in accelerating the pace of transfusion evidence generation and generalization.

Abstract Background Arising from chemoreceptor cells, carotid body tumors (CBTs) are rare neoplasms associated with hemodynamics. Perioperative changes in blood pressure (BP) and heart rate (HR) are not completely understood. Methods This retrospective, observational, controlled study included all CBT patients from 2013 to 2018 in Peking Union Medical College Hospital. Perioperative changes in BP/HR within or between unilateral/bilateral/control groups were investigated. Perioperative details across Shamblin types were also assessed. Results This study included 108 patients (116 excised CBTs). The postoperative systolic BP and HR increased in both unilateral (mean difference of systolic BP = 5.9mmHg, 95% CI 3.1 ~ 8.6; mean difference of HR = 3.7 bpm, 95% CI 2.6 ~ 4.9) and bilateral (mean difference of systolic BP = 10.3mmHg, 95% CI 0.6 ~ 19.9; mean difference of HR = 8.4 bpm, 95% CI 0.5 ~ 16.2) CBT patients compared with the preoperative measures. Compared with control group, the postoperative systolic BP increased (difference in the alteration = 6.3mmHg, 95% CI 3.5 ~ 9.0) in unilateral CBT patients; both systolic BP (difference in the alteration = 9.2mmHg, 95% CI 1.1 ~ 17.3) and HR (difference in the alteration = 5.3 bpm, 95% CI 1.0 ~ 9.6) increased in bilateral CBT patients. More CBT patients required extra antihypertensive therapy after surgery than controls (OR = 2.5, 95% CI 1.14 ~ 5.5). Maximum tumor diameter, intraoperative vascular injury, continuous vasoactive agent requirement, total fluid volume, transfusion, estimated blood loss, operation duration, postoperative pathology, overall complications, and intensive care unit/hospital lengths of stay significantly varied among Shamblin types. Conclusion CBT excision may be associated with subtle perioperative hemodynamic changes. Perioperative management of CBT patients necessitates careful assessment, full preparation and close postoperative monitoring.

Abstract Background Obesity has been recognized as the risk factor for postoperative complication for surgical patients. However, recent studies have showed protective effect of obesity in surgical and non-surgical patients. Our study is to examine the association of body mass index(BMI) with early postoperative complications in patients undergoing total knee arthroplasty. Materials and methods All patients who had primary total knee arthroplasty between January 2014 and December 2019 were included. Medical records were retrospectively reviewed and BMI was categorized as underweight(BMI

Abstract Background Low cardiac output is the main cause of perioperative death after pericardiectomy for constrictive pericarditis. We investigated the associated risk factors and consequences. Methods We selected constrictive pericarditis patients undergoing isolated pericardiectomy from January 2013 to January 2021. Postoperative low cardiac output was defined as requiring mechanical circulatory support or more than one inotrope to maintain a cardiac index > 2.2 L •min−1 •m−2 without hypoperfusion, despite adequate filling status. Uni- and multivariable analysis were used to identify factors associated with low cardiac output. Cox regression was used to identify factors associated with length of hospital stay. Results Among 212 patients with complete data, 55 (25.9%) developed low cardiac output within postoperative day 1 (quartiles 1 and 2), which caused seven of the nine perioperative deaths. The rates of atrial arrhythmia, renal dysfunction, hypoalbuminemia, modest-to-severe hyponatremia, and hyperbilirubinemia caused by constrictive pericarditis were 9.4%, 12.3%, 49.1%, 10.4%, and 81.6%. The mean preoperative central venous pressure and cardiac index were 18 ± 5 cmH2O and 1.87 ± 0.45 L•min−1•m−2. Univariable analysis showed that low cardiac output patients had higher rates of atrial arrhythmia (OR 3.32 [1.35, 8.17], P = 0.007), renal dysfunction (OR 4.24 [1.94, 9.25], P < 0.001), hypoalbuminemia (OR 1.99 [1.06, 3.73], P = 0.031) and hyponatremia (OR 6.36 [2.50, 16.20], P < 0.001), greater E peak velocity variation (difference 2.8 [0.7, 5.0], P = 0.011), higher central venous pressure (difference 3 [2,5] cmH2O, P < 0.001) and lower cardiac index (difference − 0.27 [− 0.41, − 0.14] L•min−1•m−2, P < 0.001) than patients without low cardiac output. Multivariable regression showed that atrial arrhythmia (OR 4.04 [1.36, 12.02], P = 0.012), renal dysfunction (OR 2.64 [1.07, 6.50], P = 0.035), hyponatremia (OR 3.49 [1.19, 10.24], P = 0.023), high central venous pressure (OR 1.17 [1.08, 1.27], P < 0.001), and low cardiac index (OR 0.36 [0.14, 0.92], P = 0.032) were associated with low cardiac output (AUC 0.79 [0.72–0.86], P < 0.001). Cox regression analysis showed that hyperbilirubinemia (HR 0.66 [0.46, 0.94], P = 0.022), renal dysfunction (HR 0.51 [0.33, 0.77], P = 0.002), and low cardiac output (HR 0.42 [0.29, 0.59], P < 0.001) were associated with length of hospital stay. Conclusions Early recognition and management of hyponatremia, renal dysfunction, fluid retention, and hyperbilirubinemia may benefit constrictive pericarditis patients after pericardiectomy.

Abstract Background Postoperative pulmonary complications are common and associated with morbidity and mortality. Congenital scoliosis is a failure of vertebral formation and/or segmentation arising from abnormal vertebral development. Posterior fusion and osteotomy are necessary for these patients to prevent deterioration of spine deformity. The incidence of postoperative pulmonary complications in this specific group of patients, especially young children were unknown. Methods A retrospective study was conducted and electronic medical records of early-onset scoliosis patients who had primary posterior fusion and hemivertebra resection at our institution from January 2014 to September 2019 were reviewed. The demographic characteristics, the intraoperative and postoperative parameters were collected to identify the predictors of postoperative pulmonary complications. Results A total of 174 patients (57.5% boys) with a median age of 3 years old were included for analysis. Eighteen patients (10.3%) developed perioperative pulmonary complications and pneumonia (n=13) was the most common. History of recent upper respiratory infection was not related to postoperative pulmonary complications. Multifactorial regression analysis showed thoracoplasty was the only predictive risk factor of postoperative pulmonary complications. Conclusions For congenital scoliosis patients younger than 10 years old, thoracoplasty determine the occurrence of postoperative pulmonary complications. Both surgeons and anesthesiologists should pay attention to patients undergoing thoracoplasty and preventive measures are necessary.

Abstract Background Early postoperative resumption of oral intake is supposed to be safe and beneficial to patients recovery. However, practitioners still have great confusion and disagreement about postoperative resumption of oral intake. This is a nationwide survey to investigate the current status of clinical practice and practitioners’ attitude toward postoperative resumption of oral intake along with their level of understanding of the ERAS guidelines. Methods An anonymous web-based survey questionnaire via mobile social platform was carried out in mainland China from December 11–20, 2020. The Wilcoxon signed rank test or chi-square test was used to compare the propensity of the resumption of oral intake. Results Totally 5370 responses were received, and 89% of them were from anesthesiology departments. The nature of the responses from clinical practitioners was highly diverse, but each of the three surgery types showed unique patterns of ERAS implementation. The respondents were more conservative regarding the commencement of both fluid and solid diets after gastrointestinal (GI) and hepato-pancreato-biliary (HPB) surgery than after non-abdominal (NA) surgery. Most respondents agreed that early oral intake is beneficial to reduce postoperative complications improve bowel recovery and overall outcome. 55% respondents considered themselves to have a better understanding of ERAS and tended to initiate oral intake early for all three surgery types (P

Abstract Background To investigate the role of transmuscular quadratus lumborum block (TMQLB) for postoperative pain control, patient satisfaction and recovery in laparoscopic adrenalectomy. Methods Seventy-two patients aged between 18 and 70 years with an ASA I-II and scheduled for laparoscopic adrenalectomy were randomized to receive a single-shot TMQLB with 0.4 ml/kg 0.5 % ropivacaine or 0.4 ml/kg 0.9 % saline as placebo. The primary endpoint was pain on movement at 12 h after surgery evaluated by the numeric rating scale (NRS, 0–10). P-values

Abstract Background This study sought to evaluate the diagnostic accuracy of peri-operative diaphragm ultrasound in assessing post-operative residual curarization (PORC). Methods Patients undergoing non-thoracic and non-abdominal surgery under general anaesthesia were enrolled from July 2019 to October 2019 at Peking Union Medical College Hospital. A train-of-four ratio (TOFr) lower than 0.9 was considered as the gold standard for PORC. Diaphragm ultrasound parameters included diaphragmatic excursion (DE) and diaphragm thickening fraction (DTF) during quiet breathing (QB) and deep breathing (DB). The diaphragm excursion fraction (DEF) was calculated as the DE-QB divided by the DE-DB. The diaphragm excursion difference (DED) was defined as DE-DB minus DE-QB. Receiver operating characteristic curve analysis was used to determine the cut-off values of ultrasound parameters for the prediction of PORC. Results In total, 75 patients were included, with a PORC incidence of 54.6%. The DE-DB and DED were positively correlated with the TOFr, while the DEF was negatively correlated with the TOFr. The DE-DB cut-off value for predicting PORC was 3.88 cm, with a sensitivity of 85.4% (95% confidence interval [CI]: 70.1–93.9%), specificity of 64.7% (95% CI: 46.4–79.7%), positive likelihood ratio of 2.42 (95% CI 1.5–3.9), and negative likelihood ratio of 0.23 (95% CI: 0.1–0.5). The DED cut-off value was 1.5 cm, with a specificity of 94.2% (95% CI: 80.3–99.3%), sensitivity of 63.4% (95% CI: 46.9–77.9%), positive likelihood ratio of 10.78 (95% CI: 2.8–42.2), and negative likelihood ratio of 0.39 (95% CI: 0.3–0.6). Conclusions Peri-operative diaphragm ultrasound may be an additional method aiding the recognition of PORC, with DED having high specificity.

Abstract Background This observational study describes our experience delivering nusinersen through lumbar puncture with real-time ultrasound guidance in spinal muscular atrophy (SMA) patients with severe scoliosis. Results Intrathecal nusinersen via real-time ultrasound-guided lumbar puncture was given to three patients who had severe thoracic and lumbar scoliosis: a 34-year-old female with type 3a SMA, a 28-year-old male with type 2a SMA, and a 14-year-old girl with type 3a SMA. Lumbar puncture was performed without sedation under ultrasound guidance using a 22G echogenic needle in the interlaminar aspect of the L4–L5 or L5–S1 interspace and a full dose of nusinersen (12 mg/5 mL) was injected after visualizing free cerebrospinal fluid flow. Patients completed their four loading doses and one maintenance dose of nusinersen. All 15 procedures were successful and well tolerated. Conclusions Real-time ultrasound-guided lumbar puncture is an effective and radiation-free technique to administer intrathecal nusinersen in SMA patients with severe scoliosis when done by practitioners with expertise in this procedure.

Abstract Background Megaloblastic anemia or bone marrow changes could occur after prolonged nitrous oxide inhalation via vitamin B12 inactivation related DNA synthesis impairment. Previous researches have studied hematological changes with nitrous oxide exposure, but only in adults or adolescents. Pre-school age children with active hematopoietic red bone marrow are more vulnerable to potential side effects of nitrous oxide and might experience growth impairment. The purpose of our study was to analyze red blood cell morphology changes under nitrous oxide anesthesia in pre-school age children. Methods One hundred thirty-six children under 5 years old scheduled for hemivertebra resection were analyzed. According to fresh gas type in anesthesia records, 71 children who received nitrous oxide in oxygen during anesthesia maintenance were categorized into the nitrous oxide group and the other 65 who received air in oxygen were the air group. Complete blood counts in perioperative period were assessed for anemia, macrocytosis, microcytosis, anisocytosis, hyperchromatosis and hypochromatosis. The peak value and change percentage were calculated for mean corpuscular volume and red cell distribution width. Results Forty-two children in the air group (64.6%) and 30 in the nitrous oxide group (42.3%) developed anemia (P = 0.009). None developed macrocytosis in both groups. Postoperative mean corpuscular volume peaked (mean [95% confidence interval]) at 83.7(82.9–84.4) fL, and 83.2(82.4–83.9) fL and postoperative red cell distribution width at 13.8% (13.4–14.2%), and 13.9% (13.6–14.2%) for the air group and the nitrous oxide group. Both the relative change of mean corpuscular volume (P = 0.810) and red cell distribution width (P = 0.456) were similar between the two groups. Conclusions No megaloblastic red blood cell changes were observed with nitrous oxide exposure for 4 h in pre-school age children undergoing hemivertebra resection.

Abstract Background As a classic innate immunity pathway, Toll-like receptor 4 (TLR4) signaling has been intensively investigated for its function of pathogen recognition. The receptor is located not only on immune cells but also on sensory neurons and spinal glia. Recent studies revealed the involvement of neuronal TLR4 in different types of pain. However, the specific role of TLR4 signaling in the pain symptom of endometriosis (EM) remains obscure. Methods The rat endometriosis model was established by transplanting uterine horn tissue into gastrocnemius. Western blotting and/or immunofluorescent staining were applied to detect high mobility group box 1 (HMGB1), TLR4, myeloid differentiation factor-88 adaptor protein (MyD88), and nuclear factor kappa-B-p65 (NF-κB-p65) expression, as well as the activation of astrocyte and microglia. The antagonist of TLR4 (LPS-RS-Ultra, LRU) and MyD88 homodimerization inhibitory peptide (MIP) were intrathecally administrated to assess the behavioral effects of blocking TLR4 signaling on endometriosis-related pain. Results Mechanical hyperalgesia was observed at the graft site, while HMGB1 was upregulated in the implanted uterine tissue, dorsal root ganglion (DRG), and spinal dorsal horn (SDH). Compared with sham group, upregulated TLR4, MyD88, and phosphorylated NF-κB-p65 were detected in the DRG and SDH in EM rats. The activation of astrocytes and microglia in the SDH was also confirmed in EM rats. Intrathecal application of LRU and MIP alleviated mechanical pain on the graft site of EM rats, with decreased phosphorylation of NF-κB-p65 in the DRG and reduced activation of glia in the SDH. Conclusions HMGB1-TLR4-MyD88 signaling pathway in the DRG and SDH may involve in endometriosis-related hyperpathia. Blockade of TLR4 and MyD88 might serve as a potential treatment for pain in endometriosis.

Abstract Background Patient safety incident (PSI) reporting has been an important means of improving patient safety and enhancing organizational quality control. Reports of anesthesia-related incidents are of great value for analysis to improve perioperative patient safety. However, the utilization of incident data is far from sufficient, especially in developing countries such as China. Methods All PSIs reported by anesthesiologists in a Chinese academic hospital between September 2009 and August 2019 were collected from the incident reporting system. We reviewed the freeform text reports, supplemented with information from the patient medical record system. Composition analysis and risk assessment were performed. Results In total, 847 PSIs were voluntarily reported by anesthesiologists during the study period among 452,974 anesthetic procedures, with a reported incidence of 0.17%. Patients with a worse ASA physical status were more likely to be involved in a PSI. The most common type of incident was related to the airway (N = 208, 27%), followed by the heart, brain and vascular system (N = 99, 13%) and pharmacological incidents (N = 79, 10%). Those preventable incidents with extreme or high risk were identified through risk assessment to serve as a reference for the implementation of more standard operating procedures by the department. Conclusions This study describes the characteristics of 847 PSIs voluntarily reported by anesthesiologists within eleven years in a Chinese academic hospital. Airway incidents constitute the majority of incidents reported by anesthesiologists. Underreporting is common in China, and the importance of summarizing and utilizing anesthesia incident data should be scrutinized.

Abstract Background This study aimed to identify the risk factors and evaluate the prognosis of unplanned reintubation caused by acute airway compromise (AAC) after general anesthesia. Methods This case-control study included surgical patients who underwent unplanned reintubation in the operating room and postanesthesia care unit after general anesthesia between January 1, 2014, and December 31, 2018. Cases due to AAC were matched 1:4 with randomly selected controls. Results A total of 123,068 patients were included, and reintubation due to AAC was performed in 36 patients (approximate incidence 0.03%). Univariable analysis revealed that male sex, age > 65, ASA physical status 3, sepsis, heart disease history, cerebral infarction history, Cormack Lehane grade, surgery type, fresh frozen plasma infusion, increased intubation duration, white blood cell count, and creatinine clearance rate were related to AAC-caused unplanned reintubation. Multivariable analysis revealed that age > 65 (OR = 7.50, 95% CI 2.47–22.81, P 65, ASA physical status 3, head-neck or thoracic surgery and high fluid load were found to be associated with AAC-caused unplanned reintubation.

Abstract Background The optimal position for continuous adductor canal block (ACB) for analgesia after total knee anthroplasty (TKA) remians controversial, mainly due to high variability in the localization of the the adductor canal (AC). Latest neuroanatomy studies show that the nerve to vastus medialis plays an important role in innervating the anteromedial aspect of the knee and dives outside of the exact AC at the proximal end of the AC. Therefore, we hypothesized that continuous ACB at the proximal end of the exact AC could provide a better analgesic effect after TKA compared with that at the middle of the AC (which appeared to only block the saphenous nerve). Methods Sixty-two adult patients who were scheduled for a unilateral TKA were randomized to receive continuous ACB at the proximal end or middle of the AC. All patients received patient-controlled intravenous analgesia with sufentanil postoperatively. The primary outcome measure was cumulative sufentanil consumption within 24 h after the surgery, which was analyzed using Mann-Whitney U tests. P-values

Abstract Background Ultrasound guidance can increase the success rate and reduce the incidence of complications of arterial cannulation. There are few studies on the utility of the dynamic needle tip positioning (DNTP) technique versus the angle-distance (AD) technique for ultrasound-guided radial arterial cannulation in adult surgical patients. We assessed and compared the success rates and incidences of complications of these two short-axis out-of-plane techniques. Methods A total of 131 adult surgical patients were randomized into DNTP and AD groups to undergo ultrasound-guided radial artery cannulation. The primary outcome was first-pass success without posterior wall puncture. The secondary outcomes included the first-pass success rate, 10-min overall success rate, cannulation time, posterior wall puncture, and the number of skin punctures. Results The first-pass success rates without posterior wall puncture were 53.8% in the DNTP group and 44.6% in the AD group (RR = 1.22, 95% CI: 0.86–1.72; P = 0.26). The cannulation time was significantly longer (P = 0.01) in the DNTP group [79.65 (54.3–109.4) seconds] than in the AD group [47.6 (24.9–103.8) seconds]. The posterior wall puncture rate was significantly lower (P = 0.002) in the DNTP group (29.2%) than in the AD group (56.1%; RR = 0.56, 95% CI: 0.42–0.82). Conclusions There were no significant differences in the first-pass success rate, with or without arterial posterior wall puncture, or in the 10-min overall success rate between the DNTP and AD groups. However, the cannulation time was longer and the posterior wall puncture rate was lower in the DNTP group. Trial registration The trial was registered at www.clinicaltrials.gov (No: NCT03656978 ). Registered 4 September 2018.

Abstract Background Patients with diabetes mellitus are at a high risk of developing postoperative acute kidney injury. For patients receiving laparoscopic surgery, standard-pressure pneumoperitoneum (SPP) currently applied in clinical practice also undermines renal perfusion. Several studies have shown that low-pressure pneumoperitoneum (LPP) might reduce pressure-related ischemic renal injury. However, LPP may compromise the view of the surgical field. Previous studies have indicated that deep neuromuscular blockade (NMB) can ameliorate this issue. However, the conclusion is still uncertain. The hypothesis of this study is that the joint use of LPP and deep NMB can reduce perioperative renal injury in diabetic patients undergoing laparoscopic pelvic surgery without impeding the view of the surgical field. Methods This is a double-blinded, randomized controlled trial using a 2 × 2 factorial trial design. A total of 648 diabetes patients scheduled for major laparoscopic pelvic surgeries at Peking Union Medical College Hospital will be randomized into the following four groups: SPP (12–15 mmHg) + deep-NMB (post-tetanic count of 1–2) group, LPP (7–10 mmHg) + deep-NMB group, SPP + moderate-NMB (train-of-four of 1–2) group, and LPP + moderate-NMB group. The primary outcome is serum cystatin C level measured before insufflation, after deflation, 24 h postoperatively, and 72 h postoperatively. The secondary outcomes are serum creatinine level, intraoperative urine output, erythrocytes in urinary sediment, renal tissue oxygen saturation, Leiden’s surgical condition rating scale, surgery duration, and occurrence of bucking or body movement. Discussion This study will provide evidence for the effect of LPP on renal function protection in patients with diabetes undergoing laparoscopic pelvic surgery. The trial can also help us to understand whether deep NMB can improve surgical conditions. Trial registration ClinicalTrials.gov : NCT04259112 . Prospectively registered on 5 February 2020.

Abstract Background Reports of anaesthetic management of paraganglioma resection in patients with isolated L-transposition of the great arteries (L-TGA) are rare. We focus on the preoperative evaluation, intraoperative management, and postoperative care of a frail patient with “physiologically corrected” L-TGA for paraganglioma resection. Case presentation We performed general anaesthesia for a 46-year-old patient with “physiologically corrected” L-TGA undergoing open large retroperitoneal paraganglioma resection. Although the preoperative medical therapy had attained its goals, the patient went through three periods of severe episodic hypertension and tachycardia as tumour manipulation released catecholamines. Goal-directed fluid therapy based on pulse pressure variation (PPV) and point-of-care transesophageal echocardiography (TEE) imaging enabled anaesthesiologists to make rapid judgments and to regulate blood pressure in a timely manner, thereby reducing the risk of heart failure caused by massive rapid fluid bolus therapy. The patient was transferred to the intensive care unit because of intraoperative hemodynamic changes and significant blood loss. Despite transient myocardial injury (elevated troponin I), no lethal arrhythmia or complications occurred perioperatively, and the patient recovered well and was discharged 1 week later. Conclusions Goal-directed fluid therapy combined with the adoption of TEE could effectively guide fluid administration, which is helpful for anaesthesia management during operation. We recommend the routine use of TEE in such cases.

Abstract Background Total knee arthroplasty (TKA) is usually associated with moderate to severe postoperative pain. Peripheral nerve block (PNB) and local infiltration analgesia (LIA) are two major methods for postoperative analgesia. Femoral nerve block (FNB) leads to residual posterior knee pain; thus, currently sciatic nerve block (SNB) and LIA are two major options for supplementing FNB. However, the efficacy and safety of LIA compared with combined femoral and sciatic nerve block still remain controversial. Here, we conducted a study to analyze the postoperative analgesic efficacy of these two methods. Method Two hundred six patients undergoing TKA were enrolled in a retrospective cohort study. The patients received either PNB or LIA. All patients in PNB group were conducted combined femoral and sciatic nerve block. All patients were encouraged to use patient-controlled analgesia (PCA) after surgery. The postoperative visual analog scale (VAS) at rest or with movement during the first 24 h and 48 h was recorded. We analyzed the VAS of 24 h, VAS of 48 h, opioid consumption, and adverse effects between PNB group and LIA group. Chi-square test and nonparametric test were used in this study. Results There were 82 patients in the PNB group and 124 patients in the LIA group. The patients’ characteristics such as age, height, weight, and ASA showed no significant difference (P > 0.05). No significant differences were found (P > 0.05) between the two groups regarding VAS score at rest or with movement. The LIA group had less opioid consumption than the PNB group but without significant difference (P > 0.05). In both groups, the most common side effect was nausea, and the side effects showed no significant differences between groups (P > 0.05). Conclusion Local infiltration analgesia provided a similar analgesic effect and complications compared with combined femoral and sciatic nerve block in the short term. Considering less opioid consumption with local infiltration analgesia though without significant difference and its convenience, local infiltration analgesia provided better postoperative analgesia.

Abstract Background The occurrence of thrombocytopenia is as high as 7–12% in pregnancy, yet minimum platelet count safe for cesarean section remains unknown. Methods In this retrospective noninferior cohort study, we consecutively included patients undergoing cesarean section for a period of 6 years in a tertiary hospital and excluded patients at very high risk for excessive hemorrhage. The included patients with preoperative platelet count of 50–100 × 109/L were defined as the thrombocytopenic group. The control group were eligible patients with preoperative platelet count>150 × 109/L, matched to the thrombocytopenic group by age and operation timing in a 1:2 ratio. Mixed effect model was used to analyze the effect of thrombocytopenia based on a noninferiority assumption. The predefined noninferiority delta of bleeding was 50 mL. Results There was no significant difference of the calculated blood loss between the thrombocytopenic and the control group (mean difference = 8.94, 95% CI − 28.34 mL to 46.09 mL). No statistical difference was observed in the requirement for blood transfusion, visually estimated blood loss, or the incidence of adverse events between groups. Although there were more patients admitted to intensive care unit (odds ratio = 12, 95% CI 2.69–53.62, p = 0.001) in the thrombocytopenic group, most of them required critical care for reasons other than hemorrhage. The thrombocytopenic group had longer length of hospital stay (mean difference = 0.40 days, 95% CI 0.09–0.71, p = 0.011), but the difference was considered as clinically insignificant. Conclusions Preoperative moderate thrombocytopenia is not associated with increased blood loss, blood transfusion, or occurrence of adverse events in patients undergoing cesarean section in absence of additional bleeding risk.

Abstract Background Blood loss during hemivertebra resection may be substantial. Few studies have examined the risk factors of blood loss undergoing hemivertebra resection, especially those in patients under 10 years old. Methods Patients under 10 years old diagnosed with congenital scoliosis and hemivertebra were retrospectively included from January 2014 to October 2017. They all had primary posterior hemivertebra resection at Peking Union Medical College Hospital. Perioperative information was collected and multivariable linear logistic regression was performed to determine the independent risk factors of blood loss. Results One hundred three patients were included. The mean total blood loss was 346 + 178 ml. The percentage of total blood loss to the EBV was 27.0 + 13.3%. Multivariable linear logistic regression indicated that preoperative total Cobb angle (P = 0.046) and the number of fused levels (P

Abstract Background Hemoglobin measurement is important for transfusion decision-making. Pulse CO-Oximetry provides real-time continuous hemoglobin (SpHb) monitoring. The triage role of SpHb trends based on hemoglobin measurements was investigated. Methods In this diagnostic randomized controlled trial, 69 patients undergoing spine or cytoreductive surgery were randomly enrolled into SpHb-monitoring and standard-care groups. Diagnostic blood samples were drawn for CO-oximetry Hb (CoOxHb) when the SpHb decreased by 1 g/dl or at the clinician’s discretion in the standard-care group. The positive predictive value (PPV) was defined as the ability to detect a decrease in CoOxHb > 1 g/dl or a CoOxHb 1 g/dl was 93.3% in the SpHb group vs 54.5% without SpHb monitoring (p = 0.002). The PPV of CoOxHb 1 g/dl, the concordance rate for changes in hemoglobin reached 100%. The delta pairs revealed a positive correlation [ΔSpHb = 0.49 * ΔCoOxHb - 0.13; r = 0.69, 95% confidence interval (0.53, 0.82)]. No significant differences were found in the transfusion volume or postoperative anemia state. Conclusions The SpHb trend tracked changes in hemoglobin satisfactorily during surgery and more accurately estimated the appropriate timing for invasive hemoglobin measurements than the clinicians. Trial registration ChiCTR1800016290 (Prospective registered). Initial registration date was 24/05/2018.

Abstract Background Quadratus lumborum block (QLB) is increasingly gaining popularity as a novel abdominal truncal block in abdominal surgery; however, the mechanism of QLB is not yet thoroughly illustrated. The focus of our study is transmuscular QLB (TMQLB), as the latest anatomical evidence shows that anesthetics spread into the thoracic paravertebral space to exert an analgesic effect. Therefore, we designed this study to compare TMQLB with thoracic paravertebral block (TPVB) in laparoscopic renal surgery in the hope of providing clinical evidence on the analgesic mechanism of TMQLB and its application in laparoscopic renal surgery. Methods This trial is a prospective, randomized, single-center, open-label, parallel, three-arm, non-inferiority trial. We intend to include 120 participants undergoing laparoscopic nephrectomy and before surgery they will be randomized into three groups for postoperative pain control: TMQLB experimental group 1 (0.4 ml/kg body weight 0.5% ropivacaine), TMQLB experimental group 2 (0.6 ml/kg body weight 0.5% ropivacaine) or TPVB control group (0.4 ml/kg body weight 0.5% ropivacaine at vertebra T10). Patients will be excluded if they have allergy to anesthetics, infection at the injection site, are on coagulopathy or anticoagulants, on analgesics for chronic illness, have history of substance abuse or have a barrier to communication. Morphine is given in boluses of 1.5~2 mg by intravenous patient-controlled analgesia (IPCA) in the first 48 h after surgery. The primary outcome is the difference between TMQLB group 1 and the TPVB group in the mean visual analogue scale (VAS) pain score in the first 24 h after surgery. Secondary outcomes are the difference between TMQLB group 2 and the TPVB group in the mean VAS score in the first 24 h after surgery, cumulative morphine consumption, long-term pain control, dermatomal distribution of sensory loss, nausea score, pruritus score, ambulation time, time till recovery of bowel movement, quality of recovery, postoperative length of hospital stay and patient satisfaction with anesthesia. Safety data on procedure-related complications will also be summarized. Discussion This will the first randomized controlled trial to compare TMQLB with TPVB for analgesia in laparoscopic surgery. This trial aims to provide important clinical evidence to elaborate on the analgesic mechanism of TMQLB. Trial registration ClinicalTrials.gov, NCT03414281. Registered on 9 January 2018.

Abstract Background Tranexamic acid (TXA) has been routinely delivered in multisegmental spinal decompression and bone graft fusion surgeries with satisfactory outcomes in minimizing gross blood loss and transfusion demands. However, concerns remain that intravenously delivered TXA (ivTXA) may increase risks of postoperative convulsive seizures and systemic thrombogenicity. Topical use of TXA (tTXA), being more targeted to the surgical bleeding site while minimizing patient systemic exposure to ivTXA, has been successfully applied to attenuate blood losses and transfusion requirements in hip and knee arthroplasty. Yet, randomized controlled trials on tTXA efficacy and safety are still lacking in spinal surgeries. With this knowledge gap, we hypothesize that tTXA exhibits non-inferiority to ivTXA in blood conservation and clinical safety in multisegmental spinal decompression and bone graft fusion surgeries. Methods A prospective, randomized, double-blind, non-inferiority study design will be adopted. The target sample size is 176. Eligible patients will be randomly allocated to receive either ivTXA or tTXA treatment. The primary end point is the perioperative total blood loss. Secondary end points consist of visible blood losses (intraoperative, postoperative 0–24 h, postoperative 0–48 h, combined perioperative blood loss, total postoperative blood loss), postoperative hidden blood loss, plasma TXA levels, postoperative conventional coagulation monitoring (prothrombin time, activated partial thromboplastin time, fiber Bragg grating, international normalized ratio), postoperative thromboelastography monitoring (reaction time, clot formation time, clot strength, fibrinolysis), postoperative hemoglobin nadir (within postoperative 48 h), perioperative transfusion amounts and rates, and length of hospital stay. Safety end points will be monitored too. Discussion This proposed study will contribute to expanding clinical evidences of tTXA for bleeding management in major spinal surgeries. This will be a high-quality prospective randomized trial with sufficient sample size, strict methodology, and few design deficits. It will investigate the potentiality of tTXA as an alternative to ivTXA in improving the current standard of care in multisegmental spinal surgeries, thereby optimizing the enhanced recovery after surgery scheme in spinal surgeries. Trial registration ClinicalTrials.gov, NCT03011866. Registered on 5 January 2017.

Abstract Background Inadvertent intraoperative hypothermia (core temperature

Abstract Pruritus is the most common complication of intrathecal morphine; however, its exact molecular mechanism is unclear, and treatment is challenging. The analgesic effect of N-methyl-D-aspartate (NMDA) receptor antagonists and the morphine-associated increase in NMDA receptor activation suggest potential role of NMDA receptor in the spinal itch sensation. Male C57BL/6 mice were given intrathecal morphine to induce scratching behavior. The effects of NMDA, ketamine, ifenprodil and U0126 on morphine-induced pruritus and analgesia were evaluated also. The number of scratching responses was counted for 30 min post-injection to evaluate pruritus. A warm-water tail immersion assay was conducted before and until 120 min post-injection at 30-min intervals. Percent of maximal possible effect (%MPE) and area under curve (AUC) were calculated based on tail-flick latency to evaluate analgesic efficacy. Compared with control treatment, intrathecal morphine elicited an obvious scratching response and analgesic effect in a dose dependent manner. Ketamine (1 μg), ifenprodil (0.1 μg) and U0126 (0.1 μg and 1.0 μg) all significantly attenuated morphine induced scratches. Ifenprodil (0.1 μg) injection significantly prolonged the analgesic effect of intrathecal morphine. The ERK1/2 phosphorylation induced by intrathecal morphine was inhibited by ketamine, ifenprodil and U0126 as well. U0126 inhibited morphine-induced pruritus with no effect on its analgesia. Therefore, intrathecal coadministration of morphine with NMDA receptor antagonists ketamine and ifenprodil alleviated morphine-induced scratching. Intrathecal morphine increased ERK phosphorylation in the lumbar spinal dorsal horn, which may be related with morphine-induced pruritus, and was counteracted by NMDA receptor antagonists.

Abstract Background microRNA-146a-5p (miRNA-146a-5p) is a key molecule in the negative regulation pathway of TLRs and IL-1 receptor (TIR) signaling. Our recent study demonstrated that MyD88-dependent signaling pathway of TIR in the dorsal root ganglion (DRG) and spinal dorsal horn (SDH) plays a role in peripheral nerve injury-induced neuropathic pain. However, it was not clear whether and how miRNA-146a-5p regulates the TIR pathway of DRG and SDH in the development of neuropathic pain. Methods The sciatic nerve chronic constriction injury (CCI) model of rat was used to induce chronic neuropathic pain. The levels and cellular distribution of miRNA-146a-5p were detected with quantitative real-time PCR (qPCR) and fluorescent in situ hybridization (FISH). The RNA level, protein level, and cellular distribution of IRAK1 and TRAF6 that is targeted by miRNA-146a-5p were detected with qPCR, western blot, and immunofluorescent. The pain-related behavioral effect of miRNA-146a-5p was accessed after intrathecal administration. Mechanical stimuli and radiant heat were used to evaluate mechanical allodynia and thermal hyperalgesia. Results We found that the level of miRNA-146a-5p significantly increased in L4-L6 DRGs and SDH after CCI surgery; meanwhile, the protein level of IRAK1 and TRAF6 in DRGs was significantly increased after CCI. Intrathecal injection of miR146a-5p agomir or miRNA-146a-5p antagomir regulates miRNA-146a-5p level of L4-L6 DRGs and SDH. We found that intrathecal injection of miR146a-5p agomir can alleviate mechanical and thermal hyperalgesia in CCI rats and reverse the upregulation of IRAK1 and TRAF6 of L4-L6 DRGs and SDH induced by CCI. We furthermore found that intrathecal injection of miRNA-146a-5p antagomir can exacerbate the mechanical and thermal pain-related behavior of CCI rats and meanwhile increase IRAK1 and TRAF6 of L4-L6 DRGs and SDH expression even further. Conclusions miRNA-146a-5p of DRG and SDH can modulate the development of CCI-induced neuropathic pain through inhibition of IRAK1 and TRAF6 in the TIR signaling pathway. Hence, miRNA-146a-5p may serve as a potential therapeutic target for neuropathic pain.

Abstract Backgrounds Arytenoid dislocation (AD) is a rare but severe complication after general anesthesia with endotracheal intubation. We conducted a case-control study at Peking Union Medical College Hospital to identify risk factors associated with AD, including the use of an intubation stylet. Methods Patients who experienced AD were matched 1:3 with controls based on gender, age and type of surgery. Multiple conditional logistic regression was performed to determine associations between potential risk factors and AD. Results Twenty-six AD cases were retrospectively identified from 2004 through 2016. On average, arytenoid dislocation occurred in 2 cases per year, with an incidence of 0.904/100,000 (approximately 0.01%). The 26 patients who experienced AD and 78 matched control patients were enrolled in this study. All enrolled patients underwent endotracheal intubation, and a stylet was used for intubation for 38.5% (10/26) of the AD patients and 64.1% (50/78) of the controls (OR = 0.23, 0.07–0.74). A higher incidence of AD was significantly associated with longer duration of operation (OR = 1.74, 1.23–2.47). Conclusions The use of an intubation stylet for endotracheal intubation appears to protect against AD. Prolonged operation time increases the risk of AD. These factors should be considered when assessing the risks of AD associated with endotracheal intubation and in efforts to avoid this complication.

Abstract Background MyD88 is the adaptor protein of MyD88-dependent signaling pathway of TLRs and IL-1 receptor and regulates innate immune response. However, it was not clear whether and how MyD88 and related signaling pathways in the dorsal root ganglion (DRG) and spinal dorsal horn (SDH) are involved in neuropathic pain. Methods Chronic constriction injury (CCI) was used to induce neuropathic pain in the rat. The expression of MyD88, TRIF, IBA1, and GFAP was detected with immunofluorescent staining and Western blot. The expression of interleukin-1 beta (IL-1β), high mobility group box 1 (HMGB1), NF-κB-p65, phosphorylated NF-κB-p65, ERK, phosphorylated ERK, and tumor necrosis factor-alpha (TNF-α) was detected with Western blot. Pain-related behavioral effects of MyD88 homodimerization inhibitory peptide (MIP) were accessed up to 3 weeks after intrathecal administration. Results Peripheral nerve injury significantly increased the protein level of MyD88 in the DRG and SDH, but had no effect on TRIF. MyD88 was found partly distributed in the nociceptive neurons in the DRGs and the astrocytes and microglia in the SDH. HMGB1 and IL-1β were also found upregulated in nociceptive pathways of CCI rats. Intrathecal application of MIP significantly alleviated mechanical and thermal hyperalgesia in the CCI rats and also reversed CCI-induced upregulation of MyD88 in both DRG and SDH. Further investigation revealed that suppression of MyD88 protein reduced the release of TNF-α and glial activation in the SDH in the CCI rats. Conclusions MyD88-dependent TIR pathway in the DRG and SDH may play a role in CCI-induced neuropathic pain. MyD88 might serve as a potential therapeutic target for neuropathic pain.