Hemato-biochemical changes during xylazine-ketamine and xylazine-thiopentone anesthesia in dogs

Background: This study was conducted to evaluate certain haemato-biochemical changes during Xylazine-Ketamine (X-K) and Xylazine-Thiopentone (X-T) anesthesia in dogs. Methods: For this, six dogs of 18 to 25 kg BW were selected and divided into two groups: Group I (X-K) and Group II (X-T). Atropine sulfate @ 0.05 mg/kg BW (IM) was used for premedication in both groups. Dogs in Group I (n=3) were anaesthetized with Xylazine HCl @ 1.1 mg/kg BW (IM) and Ketamine HCl @ 5.5 mg/kg BW (IM), whereas Xylazine HCl @ 1.1mg/kg BW (IM) and Thiopentone sodium @ 20 mg/kg BW (IV) were used for anesthesia in Group II (n=3). In both groups, peripheral blood samples were collected from the dogs before induction of anesthetic agents (control) and thereafter on 10, 20, 30, and 40 minutes of post-induction and again after complete recovery from anesthesia to evaluate hematological changes in Total Erythrocyte Count (TEC), Haemoglobin (Hb) and Packed Cell Volume (PCV). In addition, serum biochemical changes in Total Serum Protein (TSP), Blood Urea Nitrogen (BUN), Creatinine, Sodium (Na), Potassium (K), and Chloride (Cl) were also assessed in both groups. Results: TEC, Hb, and PCV were altered significantly (P<0.05) in most of the cases, TSP was decreased significantly (P<0.05) but BUN was increased significantly (P<0.05), and creatinine was also increased in both groups during the experiment. There were mild alterations in Na, K, and Cl values after induction, and found near to the baseline (control) after recovery. Conclusions: These findings ascertained that the anesthetic combinations of X-K and X-T assert some definite haemato-biochemical changes in dogs which should be carefully judged by the veterinarians during surgical interventions to avoid anesthesia-related risks and complications.

Electrophysiological Activity and Brain Network During Recovery of Propofol Anesthesia: A Stereoelectroencephalography-Based Analysis in Patients With Intractable Epilepsy—An Exploratory Research

Background: The oscillations and interactions between different brain areas during recovery of consciousness (ROC) from anesthesia in humans are poorly understood. Reliable stereoelectroencephalography (SEEG) signatures for transitions between unconsciousness and consciousness under anesthesia have not yet been fully identified.Objective: This study was designed to observe the change of electrophysiological activity during ROC and construct a ROC network based on SEEG data to describe the network property of cortical and deep areas during ROC from propofol-induced anesthetic epileptic patients.Methods: We analyzed SEEG data recorded from sixteen right-handed epileptic patients during ROC from propofol anesthesia from March 1, 2019, to December 31, 2019. Power spectrum density (PSD), correlation, and coherence were used to describe different brain areas' electrophysiological activity. The clustering coefficient, characteristic path length, modularity, network efficiency, degrees, and betweenness centrality were used to describe the network changes during ROC from propofol anesthesia. Statistical analysis was performed using MATLAB 2016b. The power spectral data from different contacts were analyzed using a one-way analysis of variance (ANOVA) test with Tukey's post-hoc correction. One sample t-test was used for the analysis of network property. Kolmogorov-Smirnov test was used to judge data distribution. Non-normal distribution was analyzed using the signed rank-sum test.Result: From the data of these 16 patients, 10 cortical, and 22 deep positions were observed. In this network, we observed that bilateral occipital areas are essential parts that have strong links with many regions. The recovery process is different in the bilateral cerebral cortex. Stage B (propofol 3.0-2.5 μg/ml) and E (propofol 1.5 μg/ml-ROC) play important roles during ROC exhibiting significant changes. The clustering coefficient gradually decreases with the recovery from anesthesia, and the changes mainly come from the cortical region. The characteristic path length and network efficiency do not change significantly during the recovery from anesthesia, and the changes of network modularity and clustering coefficient are similar. Deep areas tend to form functional modules. The left occipital lobe, the left temporal lobe, bilateral amygdala are essential nodes in the network. Some specific cortical regions (i.e., left angular gyrus, right angular gyrus, right temporal lobe, left temporal lobe, and right angular gyrus) and deep regions (i.e., right amygdala, left cingulate gyrus, right insular lobe, right amygdala) have more significant constraints on other regions.Conclusion: We verified that the bilateral cortex's recovery process is the opposite, which is not found in the deep regions. Significant PSD changes were observed in many areas at the beginning of stop infusion and near recovery. Our study found that during the ROC process, the modularity and clustering coefficient of the deep area network is significantly improved. However, the changes of the bilateral cerebral cortex were different. Power spectrum analysis shows that low-frequency EEG in anesthesia recovery accounts for a large proportion. The changes of the bilateral brain in the process of anesthesia recovery are different. The clustering coefficient gradually decreased with the recovery from anesthesia, and the changes mainly came from the cortical region. The characteristic path length and network efficiency do not change significantly during the recovery from anesthesia, and the changes of network modularity and clustering coefficient were similar. During ROC, the left occipital lobe, the left temporal lobe, bilateral amygdala were essential nodes in the network. The findings of the current study suggest SEEG as an effective tool for providing direct evidence of the anesthesia recovery mechanism.

Esophageal achalasia detected by vomiting during induction of general anesthesia: a case report

Background Esophageal achalasia is a rare disease with a high risk of aspiration during anesthesia induction. Here, we describe our experience involving a case of undiagnosed esophageal achalasia with profuse vomiting during anesthesia induction. Case presentation A 58-year-old woman was scheduled for orthopedic surgery under general anesthesia. She vomited a large amount of watery contents during anesthesia induction, and planned surgery was postponed. After recovery from anesthesia, she informed us that she usually had to drink a large amount of water to get food into her stomach and purged watery vomit every night before sleep. However, she attributed it to her constitutional problem, not to a specific disease. She was subsequently diagnosed with esophageal achalasia and underwent Heller myotomy with Dor fundoplication before her re-scheduled orthopedic surgery. Conclusions A detailed history of dysphagia and regurgitation should be taken in preoperative examinations to prevent unexpected aspiration due to undiagnosed achalasia.

Comparison of recovery profile between sevoflurane and isoflurane as volatile agents in neurosurgery in Indian population

Background: In most instances rapid emergence from general anesthesia after intracranial neurosurgery is desirable. The most compelling reason for this is the need for the patient to cooperate with a postoperative neurological examination intended to screen for such potential intracranial disaster as hematoma formation, herniation, and cerebrovascular accidents. Anesthetic techniques were adopted to achieve rapid emergence. In this respect, inhaled anesthetic agents have an important role in influencing the recovery time after anesthesia and surgery. The aim of this study is to compare isoflurane and sevoflurane as regard to speed of recovery from anesthesia and recovery of post-operative cognitive function in Indian populationMethods: The study was carried out as randomized control, blinded study of patients undergoing neurosurgery in tertiary care hospital. Sample sizes of 60 patients were studied. They were divided into two groups. Results: Sevoflurane shows faster emergence, extubation, motor control (in form of hand squeeze) and orientation time as compared to isoflurane. Though clinically the time difference for the various variables studied was 0.8 to 2.7 min only, statistically the results were significant and supported the basis for this difference as the difference in blood gas solubility coefficient between sevoflurane and isofluraneConclusions: Sevoflurane is recommended for use for faster extubation, emergence and post-operative neurological examination. The observation shows good brain relaxation with the use of both volatile anesthetic agents

Distinct and Dissociable EEG Networks Are Associated With Recovery of Cognitive Function Following Anesthesia-Induced Unconsciousness

The temporal trajectories and neural mechanisms of recovery of cognitive function after a major perturbation of consciousness is of both clinical and neuroscientific interest. The purpose of the present study was to investigate network-level changes in functional brain connectivity associated with the recovery and return of six cognitive functions after general anesthesia. High-density electroencephalograms (EEG) were recorded from healthy volunteers undergoing a clinically relevant anesthesia protocol (propofol induction and isoflurane maintenance), and age-matched healthy controls. A battery of cognitive tests (motor praxis, visual object learning test, fractal-2-back, abstract matching, psychomotor vigilance test, digital symbol substitution test) was administered at baseline, upon recovery of consciousness (ROC), and at half-hour intervals up to 3 h following ROC. EEG networks were derived using the strength of functional connectivity measured through the weighted phase lag index (wPLI). A partial least squares (PLS) analysis was conducted to assess changes in these networks: (1) between anesthesia and control groups; (2) during the 3-h recovery from anesthesia; and (3) for each cognitive test during recovery from anesthesia. Networks were maximally perturbed upon ROC but returned to baseline 30–60 min following ROC, despite deficits in cognitive performance that persisted up to 3 h following ROC. Additionally, during recovery from anesthesia, cognitive tests conducted at the same time-point activated distinct and dissociable functional connectivity networks across all frequency bands. The results highlight that the return of cognitive function after anesthetic-induced unconsciousness is task-specific, with unique behavioral and brain network trajectories of recovery.

Slithering CSF: Cerebrospinal Fluid Dynamics in the Stationary and Moving Viper Boa, Candoia aspera

In the viper boa (Candoia aspera), the cerebrospinal fluid (CSF) shows two stable overlapping patterns of pulsations: low-frequency (0.08 Hz) pulses with a mean amplitude of 4.1 mmHg that correspond to the ventilatory cycle, and higher-frequency (0.66 Hz) pulses with a mean amplitude of 1.2 mmHg that correspond to the cardiac cycle. Manual oscillations of anesthetized C. aspera induced propagating sinusoidal body waves. These waves resulted in a different pattern of CSF pulsations with frequencies corresponding to the displacement frequency of the body and with amplitudes greater than those of the cardiac or ventilatory cycles. After recovery from anesthesia, the snakes moved independently using lateral undulation and concertina locomotion. The episodes of lateral undulation produced similar influences on the CSF pressure as were observed during the manual oscillations, though the induced CSF pulsations were of lower amplitude during lateral undulation. No impact on the CSF was found while C. aspera was performing concertina locomotion. The relationship between the propagation of the body and the CSF pulsations suggests that the body movements produce an impulse on the spinal CSF.

Anesthetic protocols for urodynamic studies of the lower urinary tract in small rodents—A systematic review

Urodynamic studies in rats and mice are broadly used to examine pathomechnisms of disease and identify and test therapeutic targets. This review aims to highlight the effects of the anesthetics on the lower urinary tract function and seeks to identify protocols that allow recovery from anesthesia and repeated measurements while preserving the function which is being studied. All studies published in English language, which compared the data obtained under various types of anesthesia and the urodynamics performed in awake animals were included. It appears that urethane, an anesthetic recommended extensively for the investigation of lower urinary tract function, is appropriate for acute urodynamic studies only. Major advantages of urethane are its stability and ability to preserve the micturition reflex. Due to its toxicity and carcinogenicity, urethane anesthesia should not be used for recovery procedures. This review evaluated available alternatives including propofol, isoflurane and combinations of urethane, ketamine/xylazine, ketamine/medetomidine, and/or fentanyl/fluanisone/midazolam. Different effects have been demonstrated among these drugs on the urinary bladder, the urethral sphincter, as well as on their neuroregulation. The lowest incidence of adverse effects was observed with the use of a combination of ketamine and xylazine. Although the variations in the reviewed study protocols represent a limitation, we believe that this summary will help in standardizing and optimizing future experiments.

Validation of the Donkey Pain Scale (DOPS) for Assessing Postoperative Pain in Donkeys

This study aimed to validate a scale for assessing acute pain in donkeys. Forty-four adult donkeys underwent castration after sedation with intravenous (IV) xylazine, induction with guaifenesin and thiopental IV, local anesthetic block, and maintenance with isoflurane. The scale was constructed from a pilot study with four animals combined with algetic behaviors described for equines. After content validation, the scale was evaluated in 40 other donkeys by three blinded and one reference evaluator, by means of edited videos referring to the preoperative and postoperative periods: before anesthesia, 3–4 h after recovery from anesthesia, 5–6 h after recovery from anesthesia (2 h after analgesia with flunixin—1.1 mg/kg, dipyrone—10 mg/kg, and morphine—0.2 mg/kg) IV, and 24 h after recovery. Content validity, sensitivity, specificity, and responsiveness of behaviors were investigated to refine the scale. Intra- and inter-evaluator reliabilities were investigated by the weighted kappa coefficient, criterion validity by comparing the scale with the visual analog scale (VAS), internal consistency by Cronbach's α coefficient, item-total correlation by the Spearman coefficient, and intervention point for rescue analgesic by the receiver operating characteristics curve and Youden index. The scale showed very good intra-evaluator reliability (0.88–0.96), good to moderate (0.56–0.66) inter-evaluator reliability, responsiveness for all items, good criterion validity vs. VAS (0.75), acceptable internal consistency (0.64), adequate item-total correlation, except for head position and direction, and according to the principal component analysis, good association among items. The accuracy of the point for rescue analgesic was excellent (area under the curve = 0.91). The rescue analgesic score was ≥ 4 of 11 points. The scale can diagnose and quantify acute pain in donkeys submitted to castration, as the instrument is reliable and valid, with a defined intervention analgesic score.