Automated anesthesia systems-gastrointestinal endoscopy (AAS-GE): protocol for a multi-center, randomized controlled trial

Hai-Long Bing¹^#, Shi-Ying Li¹^#, Yuan-Wen Li¹, Qi-Min Wang¹, Yan Wang¹, Liu-Mei Li¹, Sheng-Qun Liu², Zhen-Hua Hu², Tian-Wei Wang³, Qing-Wang Lu⁴, Jian Huo⁵, An-Min Hu⁶, Zheng-Yuan Xia¹˒⁷, Qin-Jun Chu¹*

Abstract

Introduction: Maintaining an appropriate depth of anesthesia requires precise drug titration, traditionally managed manually by anesthesiologists, which can be subject to variability and delayed responses. Recent advances in artificial intelligence (AI) have enabled the development of automated anesthesia systems that show promise in improving control accuracy, reducing drug use, and managing hemodynamic stability. With the rising demand for gastrointestinal endoscopy and a shortage of anesthesiologists, AI-assisted anesthesia offers a potential solution to enhance procedural efficiency and safety. This study protocol outlines the AAS-GE trial, which aims to evaluate the effectiveness and safety of an AI-based anesthesia system compared to conventional manual control, using ciprofol as the sedative agent.

Methods: This study proposes to conduct a 2-arm, parallel-group, multi-center, randomized controlled trial to evaluate the efficacy and safety of an AI-assisted anesthesia system (AAS-GE) compared to traditional manual anesthesia administration in patients undergoing painless gastrointestinal endoscopy, where approximately 420 patients will be included. In the control group, anesthesia will be initiated and managed by anesthesiologists based on patients’ vital signs and clinical judgment, without reference to the BIS value. In the AAS-GE Group, anesthesia was administered using AAS-GE, which delivers continuous boluses of anesthetic drugs tailored to the patient's height, weight, age, gender, and real-time monitored data, including anesthesia depth and vital signs. The primary outcome will be the incidence of hypoxemia during the procedure, defined as a SpO2 level below 92% at any point, with oxygen supplied at 3 L/min. Secondary outcomes will include hemodynamic parameters, anesthetic management and procedure metrics, and postoperative complications.

Ethics and dissemination: This protocol has been approved by the Ethics Committee of Zhengzhou Central Hospital (Approval number: ZXYY2025055. Approved 24 April 2025. Ver. 1.1). Results will be submitted to international peer- reviewed journals.

Trial registration: NCT06857344

Intelligent Anesthesia 2025;05(1):1; https://doi.org/10.63794/ia25001

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Development and validation of a reinforcement learning algorithm to dynamically optimize mechanical ventilation in patients with moderate-severe acute respiratory distress syndrome: A multicenter observational study

Hui-Ping Li, MD, PhD,1,2,3 Huo Jian, M. Sc4 Ying-Liu, PhD,5 Zhen Li, PhD,6,7 An-Min Hu, MD,2,3,8,9*

Abstract

Background: To enhance the outcomes for moderate to severe forms of Acute Respiratory Distress Syndrome (ARDS), a personalized lung-protective ventilation approach may be necessary. The challenge lies in personalizing medicine due to the heterogeneous nature of lung stress/strain.

Objective: Our goal is to propose a dynamic ventilation regimen for ARDS patients via three reward frameworks.

Methods: This research is based on a retrospective analysis of datasets from MIMIC and eICU databases. AI systems are used in the framework of this study to optimize ideal body weight-adjusted tidal volume (Vt) and positive end-expiratory pressure (PEEP). The systems rely on reinforcement learning and focus on prognosis, platform pressure, and driving pressure.

Results: Our study incorporates 16,487 patients with moderate to severe ARDS. On average, the reward from the AI systems' treatment selection is consistently higher than that of human clinicians. The AI systems were more likely to adjust Vt by roughly 1.5 times and PEEP by about 2.0 times compared to human clinicians. Notably, the lowest mortality was observed in ARDS patients when the actual doses aligned with the AI-platform's decisions.

Conclusions: Our model provides individualized and easily interpretable treatment decisions for moderate to severe ARDS patients, potentially enhancing their prognosis. The reward framework based on platform pressure and driving pressure may be a promising avenue for future research in reinforcement learning models of mechanical ventilation.

Trial registration: Not applicable.

Keywords: Acute Respiratory Distress Syndrome; Mechanical Ventilation; Reinforcement Learning; Prognosis; Platform Pressure, Driving Pressure

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Mortality according to the cumulative time at different systolic blood pressure levels in critically ill patients: a retrospective cohort study.

Hejie Shi, MSMS1, 2, 3, Xueping Zhang, MSMS1, 2, 3, Yifei Lu, MSMS2,3, Xinyun Zhang, MSMS1, 2, 3, Wei Shi, MSMS1, 2, 3, Yuanxu Jiang, MSMS1, 2, 3, Anmin Hu, MSMS1, 2, 3, Jian Huo, MSMS4*

Abstract

Background: Previous research has shown a non-linear relationship between systolic blood pressure (SBP) and patient outcomes, with increased risks at both low and high SBP levels. However, the specific association between different SBP levels and outcomes in critically ill patients remains unclear. This study aimed to investigate the relationship between the cumulative time spent at various SBP levels and mortality in this patient population.

Methods: A retrospective analysis was conducted using data from the MIMIC-III database, encompassing over 3 million SBP records from 30,833 patients. The associations between cumulative time spent within four SBP ranges (<100, 100-120, 120-140, and ≥140 mmHg) and 12-month mortality were evaluated. Restricted cubic splines and multivariable Cox regression models were employed to assess the relationships between the percentage of cumulative time at different SBP levels (categorized into four levels: <25%, 25-50%, 50-75%, and ≥75%) and mortality after intensive care unit (ICU) admission.

Results: The study found that prolonged periods with SBP <100 mmHg were associated with a higher risk of mortality, while time spent with SBP within the 120-140 mmHg range was associated with reduced mortality risk. Patients spending the highest percentage of cumulative time at SBP <100 mmHg exhibited an approximately 4.24-fold increased risk of 12-month mortality compared to those in the lowest percentage category. Conversely, patients with the highest percentage of cumulative time at SBP 120-140 mmHg demonstrated a lower adjusted risk of mortality at 12 months (OR, 0.49; CI, 0.42-0.56) compared to those in the lowest percentage category.

Conclusion: The results of this study suggest that for critically ill patients, SBP <100 mmHg is associated with increased mortality following ICU admission, whereas maintaining SBP within the 120-140 mmHg range may lead to improved outcomes. Further research, specifically randomized trials, is necessary to establish whether interventions targeting this optimal SBP range after ICU admission can effectively enhance patient outcomes.

Key words: Systolic Blood Pressure, Mortality Benefit, Risk Exposure, Critically Ill Patients.

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Comparison of remazolam and propofol on the recovery of psychomotor function after painless gastrointestinal endoscopy

Shuang-yan Hu, MSMS1, Junfeng Hu, MSMS1, Lin-ling Mao, MSMS1, Yu-hong Zhao, MSMS1, Cheng Xu, MSMS1, Kai Qiu, MSMS1, Jun-feng Zhong, PhD1

Abstract

Background: To enhance the outcomes for moderate to severe forms of Acute Respiratory Distress Syndrome (ARDS), a personalized lung-protective ventilation approach may be necessary. The challenge lies in personalizing medicine due to the heterogeneous nature of lung stress/strain.

Objective: To compare the recovery of psychomotor function after intravenous anesthesia with remimazolam or propofol combined with alfentanil in patients undergoing painless gastrointestinal endoscopy.

Methods: Seventy-eight patients undergoing painless gastrointestinal endoscopy were randomly divided into Group RA and Group PA. Remimazolam or propofol, in combination with alfentanil, was administered intravenously in Group RA or Group PA, respectively. Blood pressure, heart rate, respiratory rate, and oxygen saturation (SpO₂) were recorded before the procedure (T1), during the procedure (T2), upon awakening from anesthesia (T3), and at discharge from the PACU (T4). Psychomotor function was evaluated using the Trieger Dot Test (TDT) and the Digit Symbol Substitution Test (DSST) at T1, T4, 1 hour post-procedure (T5), and 2 hours post-procedure (T6).

Results: Assessment of the TDT showed that the number of dots missed (NDM), the maximum distance of dots missed (MDDM), and the average distance of dots missed (ADDM) at T4 and T5 were significantly lower than at T1 in both groups. The completion rates and accuracy rates of the DSST at T4 and T5 were significantly lower than at T1. However, results of the TDT and DSST at T6 were not significantly different from those at T1. At T4 and T5, the NDM, MDDM, and ADDM values in Group RA were significantly lower than those in Group PA. The completion and accuracy rates of the DSST at T4 and T5 in Group RA were significantly higher compared to Group PA. Additionally, the incidence of hypotension was significantly lower in Group RA compared to Group PA, while there was no significant difference in the incidence of respiratory depression between the groups.

Conclusions: Psychomotor function fully recovered within 2 hours after surgery when remimazolam combined with alfentanil was used for painless gastrointestinal endoscopy. Compared to propofol, psychomotor function recovery in the remimazolam group was faster, with fewer adverse effects observed post-surgery.

Trial registration: Not applicable.

Keywords: Remimazolam; Alfentanil; Propofol; Gastrointestinal Endoscopy; Psychomotor Function

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32Clinical observation of low dose esketamine for the prevention and treatment of hyperalgesia after remifentanil general anesthesia

Tao Feng, MSMS1, Gang Liu, MSMS1, Xiang-tian Yu, MSMS1, Min Li, MSMS1, Jing Tao, MSMS1, Qi-sheng, Liang PhD1

Abstract

Background:Remifentanil is a short-acting opioid used in general anesthesia but can cause remifentanil-induced hyperalgesia (RIH). Esketamine, an NMDA receptor antagonist, is a potent anesthetic adjunct that can help prevent hyperalgesia and improve recovery outcomes. They may help improve pain management and accelerate recovery.

Objective:To investigate the effects of low-dose esketamine on the incidence of hyperalgesia, pain severity, analgesic dosage, and safety after general anesthesia with remifentanil.

Methods:Eighty patients scheduled for elective radical cervical cancer surgery were randomly assigned to either the esketamine group (Group E) or the control group (Group C), with 40 patients in each. Group E received intravenous esketamine (0.12 mg/(kg·h)) post-induction, while Group C received saline. Various parameters, including mean arterial pressure (MAP), heart rate (HR), postoperative hyperalgesia, pain onset time, VAS and OAA/S scores, analgesic pump use, and adverse reactions, were recorded.

Results:Group E had higher MAP and HR at certain time points (T3-T6) than Group C (P < 0.05). Postoperative hyperalgesia occurred in 10% of Group E patients vs. 40% in Group C (P < 0.05). Group E had a delayed first pain occurrence, lower VAS scores, and higher OAA/S scores compared to Group C (P < 0.05). Additionally, Group E used less analgesic pump solution with better postoperative analgesia (P < 0.05), with no significant difference in adverse reactions between groups (P > 0.05).

Conclusions:The application of esketamine in patients undergoing radical surgery for cervical cancer resulted in stable intraoperative hemodynamics and satisfactory postoperative analgesia and effectively prevented and controlled remifentanil-induced hyperalgesia.

Trial registration:Not applicable.

Keywords:Esketamine; Hyperalgesia; Remifentanil; Postoperative analgesia

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Effect of intranasal dexmedetomidine on emergence agitation during general anesthesia in elderly patients with renal insufficiency

Qian Chang, MSMS¹, Hai-long Yue, MSMS², Yan-rong Xu, MSMS², Miao-miao Han, MSMS¹, Guo-qing Hou, PhD²

Abstract

Background: Dexmedetomidine can effectively reduce emergence agitation in elderly patients with renal insufficiency undergoing general anesthesia. This can improve patient comfort and reduce the risk of postoperative complications.

Objective: To investigate the effect of intranasal dexmedetomidine on emergence agitation during general anesthesia in elderly patients with renal insufficiency

Methods: A total of 100 elderly patients with renal insufficiency undergoing gastrointestinal surgery at Tangshan Central Hospital, Hebei Province, from February 2023 to February 2024 were selected and randomly divided into two groups of 50. The observation group received intranasal dexmedetomidine 1 hour before the end of surgery, while the control group received the same volume of 0.9% sodium chloride nasal drops at the same time. Anesthesia recovery index, pain level, sedation effect, renal function, and adverse reactions were compared between the two groups.

Results: The recovery times for spontaneous breathing and anesthesia in the observation group were shorter than in the control group (both P < 0.05). The visual analogue scale (VAS) pain scores in the observation group were significantly lower than those in the control group at 6, 12, 24, and 48 hours after anesthesia recovery (all P < 0.001). Ramsay sedation scores immediately, and at 5, 30, and 60 minutes after extubation, were higher in the observation group than in the control group (all P < 0.001). The observation group showed lower levels of blood urea nitrogen, serum creatinine, 24-hour urinary albumin, and 24-hour urinary microalbumin excretion rate than the control group (all P < 0.001). The total incidence of adverse reactions in the observation group was significantly lower than in the control group (8.0% (4/50) vs. 46.0% (23/50), χ² = 18.316, P < 0.001).

Conclusions: Intranasal dexmedetomidine in elderly patients with renal insufficiency undergoing general anesthesia provides effective analgesic and sedative effects, shortens respiratory and anesthesia recovery times, reduces agitation during recovery, promotes better renal function recovery, minimizes adverse reactions, and is safe and effective.

Trial registration: Not applicable.

Keywords: Renal insufficiency; Dexmedetomidine; General anesthesia; Emergence agitation

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Effect of dexmedetomidine on hemodynamics in abdominal surgery patients undergoing intravenous-inhalation combined general anesthesia

Ying Xu, MD¹, Ying-jie Jin, PhD²*

Abstract

Background: Abdominal surgery is a common surgical procedure with a wide range of applications in treating various diseases. Anesthetic protocol and drug selection significantly influence surgical outcomes in abdominal procedures. Dexmedetomidine is widely used as an efficient adjunct in surgical anesthesia, however its effect on patients’ hemodynamics in abdominal surgery is poorly investigated.

Objective: To investigate the effects of dexmedetomidine on hemodynamics in patients undergoing abdominal surgery with intravenous-inhalation combined general anesthesia.

Methods: A total of 100 patients scheduled for major elective abdominal surgery at Suzhou Yongding Hospital from January 2021 to February 2024 were selected. Using a random number table, patients were divided into a control group and a study group, each with 50 patients. The control group received inhalational anesthesia with sevoflurane in combination with opioid analgesics and muscle relaxants. The study group received an intravenous infusion of dexmedetomidine at 0.8 μg/(kg·h) at the start of surgery, along with inhalation of sevoflurane at 0.8 minimum alveolar concentration, combined with opioid analgesics and non-depolarizing muscle relaxants. Surgical indicators, Visual Analogue Scale (VAS) pain scores, and incidence of adverse events were compared between the groups.

Results: Both groups successfully completed anesthesia and surgery. Compared to the control group, the study group experienced less intraoperative circulatory fluctuation, resulting in more stable vital signs. There was no significant difference between the two groups in terms of surgical duration, recovery time, resting VAS pain score at 1 hour postoperatively, or incidence of nausea and vomiting (P > 0.05). The study group’s mean arterial pressure (MAP) remained stable at various time points, whereas the control group exhibited greater variability in MAP. The MAP values at T1-T4 were significantly different between the groups (P < 0.05).

Trial registration: Not applicable.

Keywords: Abdominal surgery; General anesthesia; Dexmedetomidine; Adverse events; Hemodynamics

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Effect of dexmedetomidine on neurological and cognitive functions and inflammatory factor expression in elderly patients undergoing knee arthroplasty

Xiao-ying Xie, MSMS1, Bo Gao, MSMS1, Bing-qiang Zheng, MSMS1, Meng Meng, MSMS1, Qi-wei Zhang, MSMS1*

Abstract

Background: Total knee arthroplasty (TKA) in elderly patients with osteoarthritis can lead to inflammation and postoperative cognitive dysfunction (POCD). Dexmedetomidine may reduce these adverse effects, but the optimal dosage to minimize postoperative complications is still under investigation.

Objective: This study aims to investigate the effects of dexmedetomidine on neurological function, cognitive function, and inflammatory factor expression in elderly patients undergoing knee arthroplasty.

Methods: A total of 120 elderly patients who underwent unilateral total knee arthroplasty (TKA) from March 2022 to March 2023 were enrolled and divided randomly into four groups (A, B, C, D), each with 30 patients. Group A received combined spinal-epidural anesthesia, while groups B, C, and D received additional dexmedetomidine at a loading dose of 0.5 μg/kg, followed by continuous intravenous infusion at rates of 0.30, 0.50, and 0.80 μg/(kg·h), respectively. Serum levels of inflammatory factors, markers of brain tissue injury, and Montreal Cognitive Assessment Scale (MoCA) scores were compared before and after surgery among the groups. Postoperative cognitive dysfunction (POCD) and adverse events were also recorded.

Results: Serum TNF-α, IL-6, and IL-10 levels in all groups were higher at 1 hour, 1 day, and 3 days post-surgery than pre-surgery (P < 0.05). Serum S-100β and ICAM-1 levels increased post-surgery in all groups but were significantly lower in group D than in groups A, B, and C, and lower in group C than in groups A and B (P < 0.05). MoCA scores in groups A and B at 1, 3, and 7 days post-surgery were lower than pre-surgery (P < 0.05). MoCA scores in groups C and D decreased at 1 and 3 days post-surgery but returned to preoperative levels by day 7. MoCA scores in group D were higher than those in groups A, B, and C at 1, 3, and 7 days post-surgery, and higher in group C than in groups A and B (P < 0.05). The incidence of POCD on day 3 post-surgery was lower in group D than in groups A and B and lower in group C than in group A (P < 0.05). There was no significant difference in hypotension or bradycardia among the four groups (P > 0.05).

Conclusions: Continuous intraoperative infusion of dexmedetomidine at a rate of 0.80 μg/(kg·h) significantly reduces postoperative inflammatory, neurological, and cognitive injuries in elderly patients undergoing knee arthroplasty, ensuring anesthesia safety.

Trial registration: Not applicable.

Keywords: Dexmedetomidine; Anesthesia; Knee arthroplasty; Tumor necrosis factor-alpha; Interleukin-6; Cell adhesion molecule-1; Astrocyte-derived protein; Cognitive dysfunction

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