Inhaled Nitric Oxide ReDuce postoperatIve pulmoNAry complicaTions in patiEnts with recent COVID-19 infection (INORDINATE): protocol for a randomised controlled trial.

BACKGROUND: A history of SARS-CoV-2 infection has been reported to be associated with an increased risk of postoperative pulmonary complications (PPCs). Even mild PPCs can elevate the rates of early postoperative mortality, intensive care unit (ICU) admission and prolong the length of ICU and/or hospital stays. Consequently, it is crucial to develop perioperative management strategies that can mitigate these increased risks in surgical patients who have recently been infected with SARS-CoV-2. Accumulating evidence suggests that nitric oxide (NO) inhalation might be effective in treating COVID-19. NO functions in COVID-19 by promoting vasodilation, anticoagulation, anti-inflammatory and antiviral effects. Therefore, our study hypothesises that the perioperative use of NO can effectively reduce PPCs in patients with recent SARS-CoV-2 infection. METHOD AND ANALYSIS: A prospective, double-blind, single-centre, randomised controlled trial is proposed. The trial aims to include participants who are planning to undergo surgery with general anaesthesia and have been recently infected with SARS-CoV-2 (within 7 weeks). Stratified allocation of eligible patients will be performed at a 1:1 ratio based on the predicted risk of PPCs using the Assess Respiratory Risk in Surgical Patients in Catalonia risk index and the time interval between infection and surgery.The primary outcome of the study will be the presence of PPCs within the first 7 days following surgery, including respiratory infection, respiratory failure, pleural effusion, atelectasis, pneumothorax, bronchospasm and aspiration pneumonitis. The primary outcome will be reported as counts (percentage) and will be compared using a two-proportion χ2 test. The common effect across all primary components will be estimated using a multiple generalised linear model. ETHICS AND DISSEMINATION: The trial is approved by the Institutional Review Board of Xijing Hospital (KY20232058-F1). The findings, including positive, negative and inconclusive results, will be published in scientific journals with peer-review processes. TRIAL REGISTRATION NUMBER: NCT05721144.

Association between postoperative nadir platelet count and postoperative cardiovascular complications following septal myectomy in patients with hypertrophic cardiomyopathy: a retrospective cohort study.

BACKGROUND: Platelet count is associated with cardiovascular risk and mortality in several cardiovascular diseases, but the association of the nadir platelet counts post-septal myectomy with the cardiovascular complication risk in hypertrophic obstructive cardiomyopathy patients remains unclear. METHODS: This retrospective cohort study reviewed all adult patients who underwent septal myectomy at a single tertiary referral center over a 5-year period. Postoperative nadir platelet count was defined as the lowest platelet count in the first 4 postoperative days or until hospital discharge. The composite outcome included cardiovascular death, myocardial infarction, heart failure, malignant arrhythmia, cardiac tamponade, and major bleeding events within 30 days postoperatively. Univariable and multivariable logistic regression and restricted cubic spline models were used to assess the association between postoperative nadir platelet count and the 30-day postoperative cardiovascular complication risk. RESULTS: Among the 113 enrolled patients, 23 (20.4%) developed cardiovascular events within 30 days postoperatively. The incidence of postoperative cardiovascular complications was significantly higher in patients with a nadir platelet count ≤ 99 × 109/L than in those with a nadir platelet count > 99 × 109/L (33.3% vs. 7.1%, crude risk ratio: 4.67, 95% confidence interval: 1.69-12.85, P < 0.001). Multivariable logistic regression revealed that postoperative nadir platelet count was negatively associated with 30-day postoperative cardiovascular complications (adjusted odds ratio: 0.97; 95% confidence interval: 0.95-0.99; P = 0.005) and the association was linear (Pnonlinearity = 0.058) after full adjustment. The association between nadir platelet count and cardiovascular complications within 30 days post-surgery was consistent in all predefined subgroups (Pinteraction > 0.05). CONCLUSION: The postoperative nadir platelet count was significantly associated with the 30-day post-myectomy risk of cardiovascular complications in hypertrophic obstructive cardiomyopathy patients. TRIAL REGISTRATION: This trial was registered at ClinicalTrials.gov (NCT04275544).

Association Between Loop Diuretics and Mortality in Patients With Cardiac Surgery-Associated Acute Kidney Injury: A Retrospective Propensity Score-Weighted Analysis.

BACKGROUND: Although loop diuretics (LDs) have been widely used in clinical practice, their effect on mortality when administered to patients experiencing cardiac surgery-associated acute kidney injury (CS-AKI) remains unknown. The study aimed to investigate the effectiveness of LD use in patients with CS-AKI. METHODS: Patients who underwent cardiac surgery with AKI were identified from the Medical Information Mart for Intensive Care III. Postoperative LD use in intensive care units (ICUs) was exposure. There were 2 primary outcome measures, the in-hospital mortality and ICU mortality; both were treated as time-to-event data and were analyzed via multivariable Cox proportional hazard models. Inverse probability weighting (IPW) was used to minimize bias. RESULTS: The study enrolled a total of 5478 patients, with a median age of 67 years, among which 2205 (40.3%) were women. The crude in-hospital and ICU mortality rates were significantly lower in the LD use group (525 of 4150 [12.7%] vs 434 of 1328 [32.7%], P < .001; 402 of 4150 [9.69%] vs 333 of 1328 [25.1%], P < .001). Adjusted hazard ratios suggested significant reductions in both in-hospital (hazard ratio [HR], 0.428; 95% confidence interval [CI], 0.374-0.489) and ICU mortality (HR, 0.278; 95% CI, 0.238-0.327). The IPW data showed a similar reduction, in-hospital mortality (HR, 0.434; 95% CI, 0.376-0.502) and ICU mortality (HR, 0.296; 95% CI, 0.251-0.349). Such association may act differently for patients with different fluid balance (P value for interaction < .001). CONCLUSIONS: LD use is associated with lower hospital and ICU mortality in CS-AKI patients in general. Patients under different conditions showed diverse responses toward such treatment indicating that personalized management is needed.

Association of intraoperative cerebral and somatic tissue oxygen saturation with postoperative acute kidney injury in adult patients undergoing multiple valve surgery.

BACKGROUND: The association between tissue oxygenation with postoperative acute kidney injury (AKI) in adult patients undergoing multiple valve surgery has not been specifically studied. METHODS: In this prospective exploratory cohort study, 99 patients were enrolled. The left forehead, the left forearm, the left upper thigh, and the left renal region tissue oxygen saturation using near-infrared spectroscopy were monitored. The association between each threshold and AKI was assessed. The relative and absolute thresholds were < 70%, < 75%, < 80%, < 85%, < 90%, < 95%, and < 100% baseline, and baseline-standard deviation (SD), -1.5 SD, -2 SD, -2.5 SD, and -3 SD. Multivariate logistic regression analysis was adopted to explore the association. RESULTS: AKI occurred in 53 (54%) patients. The absolute value-based SrrO2 thresholds associated with AKI were baseline-3 SD (odds ratio [OR], 4.629; 95% confidence interval [CI], 1.238-17.314; P = 0.023) and baseline-2.5 SD (OR, 2.842; 95% CI, 1.025-7.881; P = 0.045) after adjusting for the potential confounders, those are renal region tissue oxygen saturation of 55% and 60%, but not statistically significant after correcting for multiple testing (corrected P = 0.114 and 0.179, respectively). CONCLUSION: The SrrO2 desaturation, defined as < baseline - 2.5 SD or < baseline - 3 SD, may be associated with AKI. The thresholds need to be verified in future large-scale studies. TRIAL REGISTRATIONS: The study was registered at ClinicalTrials.gov, first trial registration: 26/10/2017, identifier: NCT03323203.

Impact of SARS-CoV-2 infection on postoperative complications of patients undergoing surgery after general outbreak in China: a protocol for multicentre prospective cohort study.

INTRODUCTION: There is currently limited evidence addressing perioperative prognosis of surgical patients during COVID-19 pandemic; especially targeting on the Chinese population since the wave in 2022. Considering a distinct feature from the rest of the world demonstrated and the fast mutation and spread of the virus, evidence most relevant to China is urgently in need. The objective of this study is to seek for supporting evidence via evidence-based risk evaluations for postoperative complications to accumulate experience for coming infection waves. METHODS AND ANALYSIS: This protocol proposes a multicentral, prospective, observational cohort study aiming to explore the link between SARS-CoV-2 infection and postoperative complications among surgical patients under general or regional anaesthesia between 16 January 2023 and 31 December 2023. A retrospective cohort covering the same period in 2019 is extracted for historic reference. Data are extracted from the health information system and anaesthesia information management system. The COVID-19 information is collected via an online survey. Missing values in weight or height will be imputed by each other with age and gender via multiple imputation. Other missing values will not be handled specially. Standard descriptive statistics will be reported followed by statistical modelling. Binomial regression with logit link is used for binary outcome. The time-to-event outcome is analysed using Cox regression with discharge from hospital further treated as a competing state. Hierarchical models will be assessed to account for temporal or central random effects. Temporal trends will be displayed with future expectations. ETHICS AND DISSEMINATION: Ethical approval is obtained from the ethical committee in Xijing Hospital (No. KY20232002-C-1); approvals are expected for each participating institute. Verbal consent will be informed and obtained prior to online survey collection. Personal information remains confidential, and publications will be deidentified. TRIAL REGISTRATION NUMBER: NCT05677815.

Changes in early postoperative outcomes and complications observed in a single center during the 2022 COVID-19 pandemic wave in China: A single-center ambispective cohort study.

BACKGROUND: Currently, the effect of the 2022 nationwide coronavirus disease 2019 (COVID-19) wave on the perioperative prognosis of surgical patients in China is unclear. Thus, we aimed to explore its influence on postoperative morbidity and mortality in surgical patients. METHODS: An ambispective cohort study was conducted at Xijing Hospital, China. We collected 10-day time-series data from December 29 until January 7 for the 2018-2022 period. The primary outcome was major postoperative complications (Clavien-Dindo class III-V). The association between COVID-19 exposure and postoperative prognosis was explored by comparing consecutive 5-year data at the population level and by comparing patients with and without COVID-19 exposure at the patient level. RESULTS: The entire cohort consisted of 3350 patients (age: 48.5 ± 19.2 years), including 1759 females (52.5%). Overall, 961 (28.7%) underwent emergency surgery, and 553 (16.5%) had COVID-19 exposure (from the 2022 cohort). At the population level, major postoperative complications occurred in 5.9% (42/707), 5.7% (53/935), 5.1% (46/901), 9.4% (11/117), and 22.0% (152/690) patients in the 2018-2022 cohorts, respectively. After adjusting for potential confounding factors, the 2022 cohort (80% patients with COVID-19 history) had a significantly higher postoperative major complication risk than did the 2018 cohort (adjusted risk difference [aRD], 14.9% (95% confidence interval [CI], 11.5-18.4%); adjusted odds ratio [aOR], 8.19 (95% CI, 5.24-12.81)). At the patient level, the incidence of major postoperative complications was significantly greater in patients with (24.6%, 136/553) than that in patients without COVID-19 history (6.0% [168/2797]; aRD, 17.8% [95% CI, 13.6-22.1%]; aOR, 7.89 [95% CI, 5.76-10.83]). Secondary outcomes of postoperative pulmonary complications were consistent with primary findings. These findings were verified through sensitivity analyses using time-series data projections and propensity score matching. CONCLUSION: Based on a single-center observation, patients with recent COVID-19 exposure were likely to have a high incidence of major postoperative complications. REGISTRATION: NCT05677815 at https://clinicaltrials.gov/ .

Cardiopulmonary Adverse Events of Remimazolam versus Propofol During Cervical Conization: A Randomized Controlled Trial.

Purpose: This study aimed to compare the cardiopulmonary safety of remimazolam and propofol in patients undergoing cervical conization. Methods: This was a single-blind, parallel, randomized controlled study. A total of 204 patients scheduled for day surgery of cold knife cervical conization received either remimazolam-alfentanil anesthesia (remimazolam group) or propofol-alfentanil anesthesia (propofol group). The primary outcome was the incidence of intraoperative cardiopulmonary adverse events (a composite outcome of hypotension, bradycardia and hypoxemia). The occurrence of hypotension, bradycardia, hypoxemia and the degree of body movement were secondary outcomes, as well as the moment at which consciousness was lost, the interval between the end of anesthesia and the operating room's release of the patient, and the overall dosage of alfentanil administered during the procedure. Results: The incidence of intraoperative cardiopulmonary adverse events was 45 (44.1%) in the remimazolam group and 72 (70.6%) in the propofol group (absolute risk difference [95% CI], -26.47% [-39.55% to -13.39%]; odds ratio (OR) [95% CI], 0.43 [0.28 to 0.65]; P < 0.001). The remimazolam group showed lower incidences of hypotension and hypoxemia compared to the propofol group (P = 0.01 for both). No significant differences were observed in the overall alfentanil dosages administered, bradycardia, bodily movement, or time to losing consciousness between the two groups. Conclusion: In patients who underwent cold knife cervical conization, remimazolam-alfentanil anesthesia was associated with a reduced incidence of intraoperative cardiopulmonary adverse events compared with propofol-alfentanil anesthesia.

Cuproptosis-Related Ferroptosis genes for Predicting Prognosis in kidney renal clear cell carcinoma.

Kidney renal clear cell carcinoma (KIRC) is a main subtype of kidney cancers. Cuproptosis and ferroptosis are correlated with immune infiltration and prognosis in tumors. However, the role of Cuproptosis-related Ferroptosis genes (CRFGs) in KIRC has rarely been fully understood. Therefore, we constructed a prognostic signature based on different expression of CRFGs in KIRC. All raw data of this study were extracted from public TCGA datasets. Cuproptosis and Ferroptosis genes were collected from the previous research. Finally, a total of 36 significantly different CRFGs were identified from TCGA-KIRC cohort. Six-gene signature (TRIB3, SLC2A3, PML, CD44, CDKN2A and MIOX) was identified by LASSO Cox regression based on the significantly different CRFGs. The CRFGs signature was correlated with worse overall survival and the AUC was 0.750. Functional enrichment indicated that CRFGs were mainly enriched in metabolism, drug resistance, tumor immunity pathways. Besides, the IC50 and immune checkpoint differentially expressed between different groups. The proposed 6-CRFGs signature is a promising biomarker to predict clinical outcomes and therapeutic responses for KIRC patient.

Perioperative parameters-based prediction model for acute kidney injury in Chinese population following valvular surgery.

Background: Acute kidney injury (AKI) is a relevant complication after cardiac surgery and is associated with significant morbidity and mortality. Existing risk prediction tools have certain limitations and perform poorly in the Chinese population. We aimed to develop prediction models for AKI after valvular cardiac surgery in the Chinese population. Methods: Models were developed from a retrospective cohort of patients undergoing valve surgery from December 2013 to November 2018. Three models were developed to predict all-stage, or moderate to severe AKI, as diagnosed according to Kidney Disease: Improving Global Outcomes (KDIGO) based on patient characteristics and perioperative variables. Models were developed based on lasso logistics regression (LLR), random forest (RF), and extreme gradient boosting (XGboost). The accuracy was compared among three models and against the previously published reference AKICS score. Results: A total of 3,392 patients (mean [SD] age, 50.1 [11.3] years; 1787 [52.7%] male) were identified during the study period. The development of AKI was recorded in 50.5% of patients undergoing valve surgery. In the internal validation testing set, the LLR model marginally improved discrimination (C statistic, 0.7; 95% CI, 0.66-0.73) compared with two machine learning models, RF (C statistic, 0.69; 95% CI, 0.65-0.72) and XGBoost (C statistic, 0.66; 95% CI, 0.63-0.70). A better calibration was also found in the LLR, with a greater net benefit, especially for the higher probabilities as indicated in the decision curve analysis. All three newly developed models outperformed the reference AKICS score. Conclusion: Among the Chinese population undergoing CPB-assisted valvular cardiac surgery, prediction models based on perioperative variables were developed. The LLR model demonstrated the best predictive performance was selected for predicting all-stage AKI after surgery. Clinical trial registration: Trial registration: Clinicaltrials.gov, NCT04237636.

Sufentanil Combined with Nalbuphine via Patient-Controlled Intravenous Analgesia After Cesarean Section: A Retrospective Evaluation.

Purpose: This retrospective study evaluated the efficacy, opioid consumption, and safety profile of two patient-controlled intravenous analgesia (PCIA) regimens (sufentanil combined with nalbuphine vs sufentanil alone) after cesarean section (CS). Patients and Methods: Parturients (n = 1808) received sufentanil combined with nalbuphine (SN group) or sufentanil alone (S group) as PCIA after CS. The primary outcome was the numeric rating scale (NRS) pain score with movement (NRS-M) at 24 h after CS. Secondary outcomes were NRS scores at rest (NRS-R) at 24 and 48 h after CS, NRS-M at 48 h after CS, cumulative PCIA bolus times, and opioid consumption during the first 24 and 48 h postoperatively, which was measured in morphine-equivalent doses. Results: The population comprised 993 and 815 subjects in the SN and S groups, respectively. At 24 and 48 h after CS, the respective NRS-M scores of the SN group (4.62, 3.37) were each significantly lower than those of the S group (5.18, 4.01; P < 0.01 for both). The corresponding NRS-S scores were similarly lower in the SN group (0.96, 0.19) than in the S group (2.05, 0.92; P < 0.01 for both). After adjusting for covariates, the SN group still had lower NRS-M than the S group at 24 h after CS (estimate adjusted = 0.565, P < 0.001). The PCIA bolus times were significantly lower in the SN group than in the S group. The rates of bradycardia and respiratory depression were lower in the SN group than in the S group. However, the rates of dizziness and postoperative hypotension were slightly higher in the SN group, and those of nausea/vomiting were comparable. Conclusion: Compared with sufentanil alone, sufentanil combined with nalbuphine for PCIA provided superior analgesia in parturient women after CS.

Transcutaneous Electrical Acupoint Stimulation Combined With Auricular Acupressure Reduces Postoperative Delirium Among Elderly Patients Following Major Abdominal Surgery: A Randomized Clinical Trial.

Background: Postoperative delirium is common in elderly patients following major surgery. This study aimed to assess the effect of transcutaneous electrical acupoint stimulation combined with auricular acupressure on the incidence of postoperative delirium among older patients undergoing major abdominal surgery. Methods: In this single-center, randomized controlled clinical trial, 210 patients aged 65 years or older undergoing major abdominal surgery were randomized to receive either intervention treatment (transcutaneous electrical acupoint stimulation started at 30 min before anesthesia until the end of the surgery, followed by intermittent auricular acupressure in the first three postoperative days; n = 105) or standard care (n = 105). The primary outcome was the incidence of delirium at the first seven postoperative days or until hospitalization depended on which came first. Secondary outcomes included delirium severity, opioid consumption, postoperative pain score, sleep quality, length of postoperative hospital stay, and postoperative 30-day complications. Enrollment was from April 2019 to March 2020, with follow-up ending in April 2020. Results: All of the 210 randomized patients [median age, 69.5 years, 142 (67.6%) male] completed the trial. The incidence of postoperative delirium was significantly reduced in patients received intervention treatment (19/105 (18.1%) vs. 8/105 (7.6%), difference, -10.5% [95% CI, -1.5% to -19.4%]; hazard ratio, 0.41 [95% CI, 0.18 to 0.95]; P= 0.023). Patients in the control group had a higher postoperative Memorial Delirium Assessment Scale (4 vs. 3; difference, -1; 95% CI, -1 to 0; P = 0.014) and a greater increase in Pittsburgh Sleep Quality Index score from baseline to postoperative day three (2.5 vs. 2.0; difference, -1; 95% CI, -2 to -1; P < 0.001) than patients in the intervention group. No significant difference was observed as of other secondary outcomes. Conclusion: In elderly patients undergoing major abdominal surgery, transcutaneous electrical acupoint stimulation combined with auricular acupressure reduced the incidence of postoperative in-hospital delirium compared with standard care. A multicenter, randomized clinical trial with a larger sample size is necessary to verify these findings. Clinical Trial Registration: [https://clinicaltrials.gov], identifier [NCT03726073].

Dynamic bonds enable high toughness and multifunctionality in gelatin/tannic acid-based hydrogels with tunable mechanical properties.

Biopolymer-based functional hydrogels with excellent mechanical properties are desired, but their fabrication remains a challenge. Learning from the tofu-making process, we developed a freely formable hydrogel with high toughness and stiffness from the hydrogen bond-rich coacervation of tannic acid and gelatin through a simple hot-pressing process that transforms the coacervate particles into a bulk hydrogel. The mechanical properties of the obtained gelatin/tannic acid hydrogel (G/T gel) can be controlled by tuning the weight ratio of tannic acid to gelatin in the gel. The G/T gel with optimum mechanical properties possesses high Young's modulus, fracture strain, and fracture energy of ∼60 MPa, ∼10, and ∼24 kJ m-2, respectively. These properties arise from the phase-separated structure and high concentration of dynamic hydrogen bonds with widely distributed bond strengths. These dynamic hydrogen bonds also enable multifunctional properties of the gel, such as self-recovery, self-healing, rebuildability and shape memory. The combination of excellent mechanical properties, good biocompatibility, and useful functionalities into one hydrogel that comes from renewable sources demonstrates the great potential of G/T gels.

Transcutaneous electrical acupoint stimulation before surgery reduces chronic pain after mastectomy: A randomized clinical trial.

STUDY OBJECTIVE: Despite multiple interventions, the incidence of chronic pain after mastectomy could be as high as 50% after surgery. This study aimed to determine the efficacy of transcutaneous electrical acupoint stimulation (TEAS) before anesthesia induction in reducing chronic pain and to compare the effect of combined acupoint TEAS with that of single acupoint TEAS. DESIGN: A multicenter randomized clinical trial. SETTING: The study was conducted at six medical centers in China from May 2016 to April 2018. Final follow-up was on October 26, 2018. PARTICIPANTS: Eligible patients were women scheduled for radical mastectomy under general anesthesia. INTERVENTIONS: Patients were randomly and equally grouped into sham control (n = 188), single acupoint (PC6, n = 198), or combined acupoints (PC6 and CV17, n = 190) TEAS groups using a centralized computer-generated randomization system. TEAS was applied for 30 min before anesthesia induction. The sham-operated control group received electrode attachment but without stimulation. Anesthesiologists, surgeons, and outcome assessors were blinded to the interventions. MEASURES: The primary endpoint was the incidence of chronic pain 6 months after surgery. Incidences were compared among the groups using the unadjusted χ2 test. RESULTS: Of the 576 randomized patients, 568 completed the trial. In the intention-to-treat analysis, post-mastectomy pain at 6 months was reported in 42 of 190 patients (22.1%) in the combined acupoints group, 65 of 188 patients (34.6%) in the sham-operated group (P = 0.007; relative risk [RR], 95% confidence interval [CI]: 0.68, 0.52-0.89), and 72 of 198 patients (36.4%) in the single acupoint group (P = 0.002; RR, 95% CI: 0.72, 0.55-0.93). Remifentanil consumption during surgery and postoperative nausea and vomiting at 24 h after surgery were lower in the combined acupoint group than that in the sham-operated group. CONCLUSION: TEAS at combined acupoints before surgery was associated with reduced chronic pain 6 months after surgery. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02741726. Registered on April 13, 2016.

Pregnancy and COVID-19: what anesthesiologists should know.

INTRODUCTION: Anesthetic management of parturients with COVID-19 is a big challenge to anesthesiologists. Limited data are available about COVID-19 during pregnancy; however, information on illnesses associated with SARS and MERS might provide insights into COVID-19's effects during pregnancy. EVIDENCE ACQUISITION: Evidence from previous reports from SARS and MERS, and from COVID-19 cases were reviewed. Concepts from guidelines from the government and academic societies were collected as well. EVIDENCE SYNTHESIS: The evidence was described and summarized. CONCLUSIONS: Principles to minimize the risk of infection as well as optimize patients' safety during obstetric anesthesia were found to include careful evaluation, tight protection, and multi-discipline-based strategy. Though vertical transmission of COVID-19 still needs more definitive evidence, strict isolation is necessary for the newborn of COVID-19 mothers. Psychological support for the parturients is also an important issue during COVID-19 pandemic.

Developing super tough gelatin-based hydrogels by incorporating linear poly(methacrylic acid) to facilitate sacrificial hydrogen bonding.

Mechanically robust protein-based hydrogels are strongly desired but their construction remains a significant challenge. In this work, gelatin, together with methacrylic acid, is used to construct a novel hydrogen-bonded hydrogel through a facile low-temperature polymerization and a subsequent dry-swell process. The obtained gel is extremely stiff and tough with a high Young's modulus and a fracture energy of 11 MPa and 8.5 kJ m-2, respectively, which are comparable to the performance of tough synthetic hydrogels, rubber, cartilage, and skin. These gels also show recovery and healing properties as well as biocompatibility and stability in physiological saline solutions. The gel is easy to prepare and exhibits a wide range of functional properties, making it a promising load-bearing material for medical applications.

Effect of dual-acupoint and single-acupoint electric stimulation on postoperative outcomes in elderly patients subjected to gastrointestinal surgery: study protocol for a randomized controlled trial.

BACKGROUND: Transcutaneous electric acupoint stimulation (TEAS) has shown benefits when used peri-operatively. However, the role of numbers of areas with acupoint stimulation is still unclear. Therefore, we report the protocol of a randomized controlled trial of using TEAS in elderly patients subjected to gastrointestinal surgery, and comparing dual-acupoint and single-acupoint stimulation. METHODS/DESIGN: A multicenter, randomized, controlled, three-arm design, large-scale trial is currently undergoing in four hospitals in China. Three hundred and forty-five participants are randomly assigned to three groups in a 1:1:1 ratio, receiving dual-acupoint TEAS, single-acupoint TEAS, and no stimulation, respectively. The primary outcome is incidence of pulmonary complications at 30 days after surgery. The secondary outcomes include the incidence of pulmonary complications at 3 days after surgery; the all-cause mortality within 30 days and 1 year after surgery; admission to the intensive care unit (ICU) and length of ICU stay within 30 days after surgery; the length of postoperative hospital stay; and medical costs during hospitalization after surgery. DISCUSSION: The result of this trial (which will be available in September 2019) will confirm whether TEAS before and during anesthesia could alleviate the postoperative pulmonary complications after gastrointestinal surgery in elderly patients, and whether dual-acupoint stimulation is more effective than single-acupoint stimulation. TRIALS REGISTRATIONS: ClinicalTrials.gov, ID: NCT03230045 . Registered on 10 July 2017.