Postoperative delirium prediction after cardiac surgery using machine learning models.

OBJECTIVE: Postoperative delirium (POD) is a common postoperative complication in elderly patients, especially those undergoing cardiac surgery, which seriously affects the short- and long-term prognosis of patients. Early identification of risk factors for the development of POD can help improve the perioperative management of surgical patients. In the present study, five machine learning models were developed to predict patients at high risk of delirium after cardiac surgery and their performance was compared. METHODS: A total of 367 patients who underwent cardiac surgery were retrospectively included in this study. Using single-factor analysis, 21 risk factors for POD were selected for inclusion in machine learning. The dataset was divided using 10-fold cross-validation for model training and testing. Five machine learning models (random forest (RF), support vector machine (SVM), radial based kernel neural network (RBFNN), K-nearest neighbour (KNN), and Kernel ridge regression (KRR)) were compared using area under the receiver operating characteristic curve (AUC-ROC), accuracy (ACC), sensitivity (SN), specificity (SPE), and Matthews coefficient (MCC). RESULTS: Among 367 patients, 105 patients developed POD, the incidence of delirium was 28.6 %. Among the five ML models, RF had the best performance in ACC (87.99 %), SN (69.27 %), SPE (95.38 %), MCC (70.00 %) and AUC (0.9202), which was far superior to the other four models. CONCLUSION: Delirium is common in patients after cardiac surgery. This analysis confirms the importance of the computational ML models in predicting the occurrence of delirium after cardiac surgery, especially the outstanding performance of the RF model, which has practical clinical applications for early identification of patients at risk of developing POD.

[Analgesic effect and mechanism of electroacupuncture on SNI rats based on microglia-BDNF-neuron signal].

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Huantiao" (GB 30) and "Weizhong" (BL 40) on the activation of glial cells, the expression of brain-derived neurotrophic factor (BDNF), excitability and the number of dendritic spines of neurons in the spinal dorsal horn in rats with spared nerve injury (SNI) of sciatic nerve, and to explore the analgesic mechanism of EA on SNI. METHODS: PartⅠ: Sixty SD rats were randomly divided into a sham operation group, a model group, an EA group and a sham EA group, 15 rats in each group. Except the sham operation group, the SNI rat model was established in the remaining groups. The rats in the sham operation group were only treated with incision without damaging the nerve. The rats in the EA group were treated with EA at "Huantiao" (GB 30) and "Weizhong" (BL 40) on the affected side, continuous wave, frequency of 2 Hz, current intensity of 1 mA, 30 minutes each time, once a day, for 14 days. The rats in the sham EA group were treated with EA at points 0.5 cm next to "Huantiao" (GB 30) and "Weizhong" (BL 40) on the affected side; the manipulation, EA parameters and treatment course were the same as the EA group. The latency of thermal foot contraction reflex and the threshold of mechanical foot contraction reflex were detected 1 day before modeling and 3, 7 and 14 days after modeling. Fourteen days after modeling, Western blot was used to detect the protein expressions of ionized binding adapter junction protein 1 (Iba-1), glial fibrillary acidic protein (GFAP), BDNF and c-Fos in the spinal dorsal horn; the expressions of Iba-1 and c-Fos proteins in the spinal dorsal horn were detected by immunofluorescence staining; immunohistochemical method was used to detect the expression of GFAP protein in the spinal dorsal horn; Golgi staining was used to detect the number of dendritic spines in spinal dorsal horn neurons. PartⅡ: Thirty SD rats were randomly divided into a control group, a BDNF group and a BDNF+anti-TrkB group, 10 rats in each group. The control group was treated with intrathecal injection of 10 µL mixture with 1︰1 of 0.9% sodium chloride solution and dimethyl sulfoxide (DMSO); the BDNF group was treated with intrathecal injection of 10 µg rat recombinant BDNF dissolved in 10 µL mixture with 1︰1 of 0.9% sodium chloride solution and DMSO; the BDNF+anti-TrkB group was treated with intrathecal injection of 10 µg rat recombinant BDNF and 30 µg tyrosine kinase receptor B (TrkB) antibody dissolved in 10 µL mixture with 1︰1 of 0.9% sodium chloride solution and DMSO. The threshold of mechanical foot retraction reflex was detected 1 day before intrathecal injection and 1, 3 and 7 days after injection. Seven days after injection, the expression of c-Fos protein in the spinal dorsal horn was detected by Western blot and immunofluorescence staining. RESULTS: PartⅠ: Compared with the sham operation group, 3, 7 and 14 days after modeling, the latency of thermal foot contraction reflex and the threshold of mechanical foot contraction reflex in the model group were decreased (P<0.05); 7 and 14 days after modeling, compared with the model group, the latency of thermal foot contraction reflex and the threshold of mechanical foot contraction reflex in the EA group were increased (P<0.05). The expressions of Iba-1, GFAP, BDNF, c-Fos proteins and the number of neuronal dendritic spines in the spinal dorsal horn in the model group were higher than those in the sham operation group (P<0.05); the expressions of Iba-1, BDNF, c-Fos proteins and the number of neuronal dendritic spines in the EA group were lower than those in the model group (P<0.05). PartⅡ: 3 and 7 days after intrathecal injection, the threshold of mechanical foot retraction reflex in the BDNF group was lower than that in the control group (P<0.05); the threshold of mechanical foot retraction reflex in the BDNF+anti-TrkB group was higher than that in the BDNF group (P<0.05). The expression of c-Fos protein in spinal dorsal horn in the BDNF group was higher than that in the control group (P<0.05); the expression of c-Fos protein in spinal dorsal horn in the BDNF+anti-TrkB group was lower than that in the BDNF group (P<0.05). CONCLUSION: The analgesic effect of EA at "Huantiao" (GB 30) and "Weizhong" (BL 40) on SNI rats may be related to inhibiting the activation of microglia in the dorsal horn of the spinal cord, thereby blocking the signal of microglia-BDNF-neuron, and finally reducing the excitability of neurons.

Effects of General Anesthesia Combined with Epidural Anesthesia on Cognitive Dysfunction and Inflammatory Markers of Patients after Surgery for Esophageal Cancer: A Randomised Controlled Trial.

OBJECTIVE: To evaluate the impact of general anesthesia (GA) combined with epidural anesthesia (GAEA) on postoperative cognitive dysfunction (POCD) and inflammatory markers in patients with esophageal cancer (EC).   Study Design: A randomised controlled trial. PLACE AND DURATION OF STUDY: Department of Anesthesiology, Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, Sichuan Province, China, from August 2019 to April 2020. METHODOLOGY: SPSS was used to randomly divide 142 cases into two groups, namely: the GA (n=71) and GAEA (n=71) categories. 128 candidates were used in this study. Cognitive function and the levels of interleukin 6 (IL-6), interleukin 8 (IL-8), and tumor necrosis markers α (TNF-α) in serum were evaluated at baseline, 1, 3 and 7 days after operation by Montreal Cognitive Assessment (MoCA) and enzyme-linked immunosorbent assay (ELISA), respectively. Pearson correlation analysis was used to assess the interrelationships between MoCA score and inflammatory markers levels. RESULTS: Compared to the GA group (n=64), the GAEA category (n=64) showed significantly higher MoCA score on 1 day and 3 days postoperatively (all p <0.05). IL-6, IL-8 and TNF-α in the GA group were significantly increased on 1, 3 and 7 days after surgery (all p <0.05). Pearson correlation analysis indicated that the three inflammatory markers were inversely correlated with cognitive function score (all p <0.05). The postoperative adverse events between the two groups were comparable (all p >0.05). CONCLUSION: Combining general and epidural anesthesia may reduce the incidence of POCD in patients undergoing esophagectomy by suppressing inflammatory response. Key Words: General anesthesia, Epidural anesthesia, Esophageal cancer, Postoperative cognitive dysfunction, Inflammatory markers.