Study of postoperative laryngopharyngeal discomfort: protocol for a single-centre cohort study.

INTRODUCTION: Postoperative laryngopharyngeal discomfort after extubation can lead to severe throat pain, dysphagia, or postoperative tongue oedema. Possible mechanisms include increased oral pressure, obstruction of venous and lymphatic return in the neck, and increased capillary hydrostatic pressure, which leads to oedema of the tongue and upper airway. However, real-time monitoring indicators of anaesthesia are lacking. Therefore, we designed this study to accurately measure the contact force of the tracheal tube on the tongue in different surgical positions during general anaesthesia. METHODS AND ANALYSIS: This prospective single-centre observational study will enrol 54 patients undergoing elective surgery under general anaesthesia for>2 hours with endotracheal tube application from 1 July 2023 to 30 June 2024. Patients will be divided into the supine (Supine group) and high-risk (Flexion group) groups. Dynamic changes in the contact force between the tracheal tube and tongue will be measured using T-Scan technology. All patients will be followed up for 7 days postoperatively. The primary endpoint is postoperative laryngopharyngeal discomfort. Secondary outcomes include the time to the first successful recovery of oral intake of fluids and solid food, and airway-related events. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Ethics Committee of Clinical Research of China-Japan Friendship Hospital (2023-KY-219, approved on 14 September 2023). Informed consent will be obtained during anaesthesia evaluation. This study aims to explore the characteristics of the contact force on the tongue caused by endotracheal intubation in different surgical positions and to provide a better understanding of the risk factors and prevention of postoperative laryngopharyngeal discomfort. The findings of this study will be presented at our hospital, reported on ClinicalTrials.gov, and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT05987293.

Protocol for a randomised controlled trial: optimisation of perioperative analgesia protocol for uniportal video-assisted thoracoscopic surgery.

INTRODUCTION: Postoperative pain after thoracic surgery impairs patients' quality of life and increases the incidence of respiratory complications. Optimised analgesia strategies include minimally invasive incisions, regional analgesia and early chest tube removal. However, little is known about the optimal analgesic regimen for uniportal video-assisted thoracoscopic surgery (uVATS). METHODS AND ANALYSIS: We will conduct a single-centre, prospective, single-blind, randomised trial. The effects of postoperative analgesia will be tested using thoracic paravertebral block (PVB) in combination with patient-controlled intravenous analgesia (PVB+PCIA), erector spinae plane block (ESPB) in combination with patient-controlled intravenous analgesia (ESPB+PCIA) or PCIA alone; 102 patients undergoing uVATS will be enrolled in this study. Patients will be randomly assigned to the PVB group (30 mL of 0.33% ropivacaine with dexamethasone), ESPB group (40 mL of 0.25% ropivacaine with dexamethasone) or control groups. PCIA with sufentanil will be administered to all patients after surgery. The primary outcome will be total opioid consumption after surgery. Secondary outcomes include postoperative pain score; postoperative chronic pain at rest and during coughing; sensations of touch and pain in the chest wall, non-opioid analgesic consumption; length of stay; ambulation time, the total cost of hospitalisation and long-term postoperative analgesia. Adverse reactions to analgesics and adverse events related to the regional blocks will also be recorded. The statisticians will be blinded to the group allocation. Comparison of the continuous data among the three groups will be performed using a one-way analysis of variance to assess differences among the means. ETHICS AND DISSEMINATION: The results will be published in patient education courses, academic conferences and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT06016777.

[Changes in Soil Organic Carbon Density and Its Response to Climate Change and Human Activities Before and After the Grain for Green Project on the Loess Plateau].

Accurately assessing the changes in soil organic carbon storage （SOCS） before and after the Grain for Green Project （GFG） in the Loess Plateau （LP） and exploring the relationship between its spatial and temporal distribution and the influencing factors were important references for the development of regional recycling as well as the formulation of ecological protection policies. Based on the data of climate, human activities, and SOCD in the surface （0-20 cm） and deep （0-100 cm） soil before and after GFG in the LP from 2001 to 2020, we investigated the changes in SOCD at different spatial and temporal scales by using the methods of trend analysis, the kriging method, and variance partitioning analysis. The results showed that： ① Before and after the GFG, the surface SOCS of the whole region increased by 8 338.7×104 t； the deep SOCS increased by 1 160.02×104 t. ② In each bioclimatic subregion, the whole-region average SOCD of Ⅰ （Semi-Humid Forest Region）, Ⅱ （Semi-Humid Semi-Arid Forest and Grassland Region）, and Ⅲ （Semi-Arid Typical Grassland Region） showed a significant increasing trend, with a decreasing trend in Ⅳ （arid semi-arid desert grassland area） and Ⅴ （arid desert area）. ③ The average surface SOCS increase in different ecosystems was ranked as follows： cropland > grassland > woodland > shrubs > bare land and sparse vegetation. The deep soil increase was ranked as follows： grassland > cropland > woodland > shrubs > bare land and sparse vegetation. ④ Climate factors were the most important driving factors for changes in SOCD； the annual average temperature and precipitation were significantly positively correlated with changes in SOCD. The results of the study could provide data support for regional ecological management and land use policy formulation to promote high quality development of the ecological environment in the LP.