Physiological properties of auditory neurons responding to omission deviants in the anesthetized rat.

The detection of novel, low probability events in the environment is critical for survival. To perform this vital task, our brain is continuously building and updating a model of the outside world; an extensively studied phenomenon commonly referred to as predictive coding. Predictive coding posits that the brain is continuously extracting regularities from the environment to generate predictions. These predictions are then used to supress neuronal responses to redundant information, filtering those inputs, which then automatically enhances the remaining, unexpected inputs. We have recently described the ability of auditory neurons to generate predictions about expected sensory inputs by detecting their absence in an oddball paradigm using omitted tones as deviants. Here, we studied the responses of individual neurons to omitted tones by presenting individual sequences of repetitive pure tones, using both random and periodic omissions, presented at both fast and slow rates in the inferior colliculus and auditory cortex neurons of anesthetized rats. Our goal was to determine whether feature-specific dependence of these predictions exists. Results showed that omitted tones could be detected at both high (8 Hz) and slow repetition rates (2 Hz), with detection being more robust at the non-lemniscal auditory pathway.

Perioperative Change of High-Sensitive Cardiac Troponin I Concentration in Cats According to Three Different Anaesthesia Protocols.

BACKGROUND: Cardiac troponin I, a particular biomarker, is released into the bloodstream in response to myocardial injury. OBJECTIVES: To evaluate perioperative changes in high-sensitivity cardiac troponin I (hs-cTnI) concentration during ovariohysterectomy in cats undergoing three different anaesthesia protocols. METHODS:  Twenty-one female mixed-breed cats owned by clients aged (2.2 ± 0.7 years) and weight (3.2 ± 0.5 kg) were included in our study. The cats were divided into three groups: propofol-isoflurane (PI) group (n = 7), xylazine-ketamine (XK) group (n = 7) and xylazine-isoflurane (XI) group (n = 7). After pre-anaesthetic propofol (6 mg/kg IV) was administered to cats in Group PI, a mask was placed, and anaesthesia was maintained with 3.0% isoflurane in oxygen. Cats in Group XK underwent general anesthetization with xylazine hydrochloride (2 mg/kg IM) and, 10 min later, ketamine hydrochloride (10 mg/kg IM). Cats in Group XI were administered xylazine hydrochloride (2 mg/kg IM), and then anaesthesia (3.0% isoflurane and oxygen) was continued with a mask. Blood samples were collected from all cats; preoperatively and postoperatively at 0 and 12 h (Pre-, Post-0 h and Post-12 h, respectively). Serum hs-cTnI concentrations were measured with the Advia Centaur TnI-Ultra. RESULTS: In all 21 cats, hs-cTnI concentration increased at Post-0 h and 12 h measurement points compared to Pre-. In the XK group, hs-cTnI concentrations exhibited a significant increase at the Post-0 h (51.30 ng/L) and Post-12 h (157.70 ng/L) time points compared to Pre- (6.70 ng/L) (p < 0.05). CONCLUSIONS: The XK group increased the concentration of hs-cTnI more than other protocols. In the PI group, the increase in hs-cTnI concentrations at Post-0 and 12 h increased less than the other two groups (p < 0.05). The PI group was found to induce less myocardial damage.

[Meta-analyses-Explained my means of examples from anesthesia and pain medicine]. / Metaanalysen ­ erklärt anhand von Beispielen aus der Anästhesie und Schmerzmedizin.

Meta-analyses are a central part of systematic reviews. The term meta-analysis describes the statistical methods to summarize the results of the available scientific studies providing the highest possible evidence. In medicine, meta-analyses aim to guide clinical decisions. This article provides an overview of the necessary work steps.The classical meta-analysis summarizes the results of randomized controlled trials that compare an intervention against a control intervention. This is illustrated by means of an example from a Cochrane Review on videolaryngoscopy in comparison to direct laryngoscopy. Crucial methodological aspects such as the weighting of individual studies when pooling their results as well as the evaluation of study heterogeneity and potential publication bias are explained.The second part of the article focusses on two extensions of meta-analyses: the individual patient data meta-analysis and the network meta-analysis. The individual patient data meta-analysis makes use of the information that is available from the patient-level data of the included studies. As an example, the work accomplished by an international collaboration on the efficacy of acupuncture in chronic pain is presented. A network meta-analysis enables the comparison of more than two interventions by making use not only of the available direct but also of the respective indirect evidence. This is illustrated by means of a Cochrane Review on drugs for the prophylaxis of postoperative nausea and vomiting.

Optimizing anesthesia management based on early identification of electroencephalogram burst suppression risk in non-cardiac surgery patients: a visualized dynamic nomogram.

BACKGROUND: Burst suppression (BS) is a specific electroencephalogram (EEG) pattern that may contribute to postoperative delirium and negative outcomes. Few prediction models of BS are available and some factors such as frailty and intraoperative hypotension (IOH) which have been reported to promote the occurrence of BS were not included. Therefore, we look forward to creating a straightforward, precise, and clinically useful prediction model by incorporating new factors, such as frailty and IOH. MATERIALS AND METHODS: We retrospectively collected 540 patients and analyzed the data from 418 patients. Univariate analysis and backward stepwise logistic regression were used to select risk factors to develop a dynamic nomogram model, and then we developed a web calculator to visualize the process of prediction. The performance of the nomogram was evaluated in terms of discrimination, calibration, and clinical utility. RESULTS: According to the receiver operating characteristic (ROC) analysis, the nomogram showed good discriminative ability (AUC = 0.933) and the Hosmer-Lemeshow goodness-of-fit test demonstrated the nomogram had good calibration (p = 0.0718). Age, Clinical Frailty Scale (CFS) score, midazolam dose, propofol induction dose, total area under the hypotensive threshold of mean arterial pressure (MAP_AUT), and cerebrovascular diseases were the independent risk predictors of BS and used to construct nomogram. The web-based dynamic nomogram calculator was accessible by clicking on the URL: https://eegbsnomogram.shinyapps.io/dynnomapp/ or scanning a converted Quick Response (QR) code. CONCLUSIONS: Incorporating two distinctive new risk factors, frailty and IOH, we firstly developed a visualized nomogram for accurately predicting BS in non-cardiac surgery patients. The model is expected to guide clinical decision-making and optimize anesthesia management.

We firstly developed a dynamic nomogram to accurately predict the risk of burst suppression (BS) in non-cardiac surgery, and provided a Quick Response (QR) code based on a web calculator to visualize it.The accuracy of the model is enhanced by the inclusion of frailty and intraoperative hypotension (IOH).Our model aims to help clinicians effectively identify the risk of BS, thus guiding clinical decision-making and optimizing anesthesia management.

The relationship between anesthesia, surgery and postoperative immune function in cancer patients: a review.

This review comprehensively examines the impact of anesthesia and surgical interventions on the immune function of cancer patients postoperatively. Recent studies have shown that surgery and its accompanying anesthesia management can significantly influence immune function in cancer patients, potentially affecting their prognosis. This review synthesizes clinical studies and basic research to summarize the specific effects of anesthesia methods, drugs, postoperative analgesia, intraoperative transfusion, surgical techniques, and trauma extent on the immune function of cancer patients post-surgery. Additionally, this review discusses optimization strategies based on current research, aiming to refine anesthesia and surgical management to maximize the preservation and enhancement of postoperative immune function in cancer patients, with the potential to improve clinical outcomes.

Effect of Oral Gabapentin before Plasmakinetic Resection of the Prostate on Anesthesia Effects in Older Adults with Benign Prostatic Hyperplasia: A Retrospective Study.

OBJECTIVE: Benign prostatic hyperplasia (BPH) is a common chronic disease affecting the health of the urinary system and the quality of life in older adults. Plasmakinetic resection of the prostate (PKRP) is one of the important surgical procedures for treating BPH; However, older adults may experience anesthesia complications and postoperative pain. This retrospective study aimed to assess the effects of preoperative oral gabapentin on anesthesia outcomes in older adults with BPH undergoing PKRP and to provide detailed clinical evidence for improving the impact of surgical treatment. METHODS: The medical records of 178 older adults with BPH who underwent PKRP in Tianjin Hospital from March 2021 to March 2023 were retrospectively analyzed. After excluding 18 patients who did not meet the inclusion criteria, 160 patients were finally included in the study. According to preoperative use of gabapentin, patients were divided into the observation group (n = 75, received gabapentin) and the control group (n = 85, did not receive gabapentin). The baseline data, visual analog scale (VAS) scores, postoperative Ramsay Sedation Scale (RSS) scores, and incidence of adverse reactions were collected. RESULTS: There were no significant differences observed between the two groups in terms of age, body mass index, prostate volume, surgery duration, International Prostate Symptom Score (IPSS), American Society of Anesthesiologists (ASA) classification, history of hypertension and diabetes mellitus, VAS scores at postoperative 36 hours and 48 hours, and RSS scores at postoperative 2 hours, 4 hours, 8 hours, 12 hours, 24 hours, 36 hours, and 48 hours (p > 0.05). Compared to the control group, the observation group had significantly lower VAS scores at postoperative 2 hours, 4 hours, 8 hours, 12 hours, and 24 hours (p < 0.001), and the incidence of adverse reactions was significantly lower within 24 hours after surgery (p < 0.05). CONCLUSIONS: Preoperative administration of gabapentin before PKRP could reduce pain severity and the incidence of adverse reactions and improve anesthetic effects in older adults with BPH, which is conducive to postoperative recovery.