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Monitoring the Depth of Anaesthesia  [PDF]
Bojan Musizza,Samo Ribaric
Sensors , 2010, DOI: 10.3390/s101210896
Abstract: One of the current challenges in medicine is monitoring the patients’ depth of general anaesthesia (DGA). Accurate assessment of the depth of anaesthesia contributes to tailoring drug administration to the individual patient, thus preventing awareness or excessive anaesthetic depth and improving patients’ outcomes. In the past decade, there has been a significant increase in the number of studies on the development, comparison and validation of commercial devices that estimate the DGA by analyzing electrical activity of the brain (i.e., evoked potentials or brain waves). In this paper we review the most frequently used sensors and mathematical methods for monitoring the DGA, their validation in clinical practice and discuss the central question of whether these approaches can, compared to other conventional methods, reduce the risk of patient awareness during surgical procedures.
Depth-of-anaesthesia monitoring
JR Sneyd
Southern African Journal of Anaesthesia and Analgesia , 2012,
Abstract: All anaesthetists would like to be confident that their patients are asleep throughout surgery. Depth-of-anaesthesia monitors may contribute to reducing the incidence of perioperative awareness, but they are expensive, and typically require that consumables are purchased for every case. Recently, excessive depth of anaesthesia has been feebly associated with increased mortality, but this has not yet been proven, and may reflect patient co-morbidity, rather than clinician error.
Intraoperative Auditory Evoked Potential Monitoring for Anaesthesia Depth and Utilization of Inhaled Isoflurane  [PDF]
Kunal Tewari, T. V. S. P. Murthy
Open Journal of Anesthesiology (OJAnes) , 2017, DOI: 10.4236/ojanes.2017.74011
Abstract: Background: Hypnosis monitoring has been shown to reduce the incidence of awareness. A-line ARX-IndexTM (AAI) derived from auditory evoked potentials (AEP) represents as a numerical variable depth of anaesthesia. Objectives: To study the efficacy of AEP as an indicator of anaesthetic depth and monitor intraoperative awareness in neurosurgical patients by using the AAI scale. Design: Prospective cohort study is used. Setting: The study is in Neurosurgical centre of Tertiary care hospital. Participants: Neurosurgical patients requiring general anaesthesia with duration of surgery between 90 - 150 minutes were enrolled for the study. Intervention: Patients in Group 1 (control) were monitored by conventional methods. Patients in Group 2 (study) underwent intraoperative monitoring by using the AEP monitor. Primary outcome: To study the efficacy of AEP monitoring and AAI index for monitoring the depth of anaesthesia and reducing the incidence of awareness. Results: There was no significant difference in the intraoperative haemodynamic responses measured between the two study groups (p > 0.5). There was no significant difference in the identification of intraoperative awareness by using conventional parameters between the two groups (p > 0.5). There was also a significantly faster time to recovery for patients in Group 2 (p < 0.05). Conclusion: Hypnosis monitoring using AEP monitor/AAI in neurosurgical patients under general anaesthesia did not show any significant difference in haemodynamic response and intraoperative awareness but had significant lower consumption of volatile anaesthetic with cost sparing effect and a faster recovery time as compared to conventional monitoring.
From conformons to human brains: an informal overview of nonlinear dynamics and its applications in biomedicine  [cached]
Klonowski Wlodzimierz
Nonlinear Biomedical Physics , 2007, DOI: 10.1186/1753-4631-1-5
Abstract: Methods of contemporary physics are increasingly important for biomedical research but, for a multitude of diverse reasons, most practitioners of biomedicine lack access to a comprehensive knowledge of these modern methodologies. This paper is an attempt to describe nonlinear dynamics and its methods in a way that could be read and understood by biomedical professionals who usually are not trained in advanced mathematics. After an overview of basic concepts and vocabulary of nonlinear dynamics, deterministic chaos, and fractals, application of nonlinear methods of biosignal analysis is discussed. In particular, five case studies are presented: 1. Monitoring the depth of anaesthesia and of sedation; 2. Bright Light Therapy and Seasonal Affective Disorder; 3. Analysis of posturographic signals; 4. Evoked EEG and photo-stimulation; 5. Influence of electromagnetic fields generated by cellular phones.
Diabetes Mellitus and Cardiovascular Prevention: The Role and the Limitations of Currently Available Antiplatelet Drugs  [PDF]
A. Tufano,E. Cimino,M. N. D. Di Minno,P. Ieranò,E. Marrone,A. Strazzullo,G. Di Minno,A. M. Cerbone
International Journal of Vascular Medicine , 2011, DOI: 10.1155/2011/250518
Abstract: Diabetes mellitus (DM) is associated with macrovascular and microvascular complications. Platelets have a “key role” in atherogenesis and its thrombotic complications in subjects with DM. Moreover, the concomitant presence of multiple “classical” cardiovascular risk factors in diabetic subjects contributes to enhanced atherothrombotic risk. Antiplatelet agents are effective in primary and secondary prevention of arterial thrombosis (cardiovascular events, ischaemic stroke, and peripheral arterial occlusive disease). The role of chronic administration of antiplatelet drugs in primary prevention of arterial vascular events is known to be less clear than in secondary prevention, and, also in diabetic patients, the decision to give primary prophylaxis should be taken on an individual-patient basis, after a careful evaluation of the balance between the expected benefits and the risk of major bleedings. Although, currently, treatment has proven useful in reducing vascular events, diabetic patients continue to have a higher risk of adverse cardiovascular events compared with those in nondiabetic patients. This paper reviews the role of currently available antiplatelet drugs in primary and secondary prevention of vascular events in diabetic patients and the limitations of these drugs, and it discusses the role of novel and more potent antiplatelets and of new agents currently under clinical development. 1. Introduction Diabetes mellitus (DM) is associated with macrovascular and microvascular complications (coronary artery disease, ischemic stroke, peripheral arterial disease, nephropathy, and retinopathy) [1, 2]. Platelets have a “key role” in atherogenesis and its thrombotic complications in subjects with DM [3], and the concomitant presence of multiple “classical” cardiovascular risk factors (arterial hypertension, cigarette smoking, and hyperlipidemia) in diabetic subjects contributes to enhanced atherothrombotic risk. Platelets from subjects with DM, particularly from those with type 2 diabetes, exhibit increased reactivity. Factors that may contribute to this greater platelet reactivity are not completely elucidated and include metabolic abnormalities as hyperglycemia, hyperlipidemia, insulin resistance, and conditions as oxidative stress, inflammation, and endothelial dysfunction [3]. A close relationship between poor glycemic control and increased platelet activity (estimated by measuring mean platelet volume—MPV—as part of whole blood count) in patients with type 2 DM has been suggested [4]. MPV is considered a marker of platelet function and
Anaesthesia Monitoring by Recurrence Quantification Analysis of EEG Data  [PDF]
Klaus Becker,Gerhard Schneider,Matthias Eder,Andreas Ranft,Eberhard F. Kochs,Walter Zieglg?nsberger,Hans-Ulrich Dodt
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0008876
Abstract: Appropriate monitoring of the depth of anaesthesia is crucial to prevent deleterious effects of insufficient anaesthesia on surgical patients. Since cardiovascular parameters and motor response testing may fail to display awareness during surgery, attempts are made to utilise alterations in brain activity as reliable markers of the anaesthetic state. Here we present a novel, promising approach for anaesthesia monitoring, basing on recurrence quantification analysis (RQA) of EEG recordings. This nonlinear time series analysis technique separates consciousness from unconsciousness during both remifentanil/sevoflurane and remifentanil/propofol anaesthesia with an overall prediction probability of more than 85%, when applied to spontaneous one-channel EEG activity in surgical patients.
Effect of Intermittent Positive Pressure Ventilation on Depth of Anaesthesia during and after Isoflurane Anaesthesia in Sulphur-Crested Cockatoos (Cacatua galerita galerita)  [PDF]
Saul Chemonges
Veterinary Medicine International , 2014, DOI: 10.1155/2014/250523
Abstract: This study aimed to determine the effect of intermittent positive pressure ventilation (IPPV) on the depth of inhalation anaesthesia in parrots. Anaesthesia was induced with 3.0% isoflurane in six Sulphur-crested Cockatoos (Cacatua galerita galerita) and maintained using either 1.5% or 3.0% during spontaneous ventilation (SV) or IPPV at 6 (IPPV-6) or 12 (IPPV-12) breaths per minute. The time taken for the appearance of somatic reflexes and the return of SV after IPPV was recorded. During recovery, the body jerk, beak, eye, and shivering reflexes appeared after 126 ± 27?s, 133 ± 26?s, 165 ± 34?s, and 165 ± 44?s, respectively. All cockatoos developed apnoea after IPPV-12 and only some did after IPPV-6. Return of SV after IPPV-12 was delayed compared to IPPV-6. Recovery times after the SV runs were significantly different between 1.5% and 3.0% isoflurane anaesthesia. Similarly, after IPPV, the recovery times were significantly different between 1.5% and 3.0% isoflurane anaesthesia. Recovery times after 3.0% inhaled isoflurane were longer than those of 1.5% inhaled isoflurane. In conclusion, cockatoos recovering from isoflurane anaesthesia are likely to exhibit body jerk, beak, eye, and shivering reflexes in that order. IPPV increases the depth of anaesthesia in a rate and dose-related manner and prolongs recovery. 1. Introduction Isoflurane continues to be a popular anaesthetic agent for birds [1–3], due to its relative safety and effectiveness [4], and changes in the depth of anaesthesia and recovery can be easily and quickly controlled [5, 6]. Its faster induction and recovery, relative sparing effect on cardiovascular function and cerebral blood flow autoregulation, and negligible metabolism make isoflurane useful in the anaesthetic management of debilitated, aged, or exotic veterinary patients [3, 7]. Most of it is eliminated via the lungs with only a minute fraction metabolised in the liver [8–10]. Other anaesthetic inhalation agents such as sevoflurane [5, 6, 8, 9, 11–20] and desflurane [18] may have slight advantages over isoflurane; however, associated costs are considerable which limits their widespread use in veterinary practice. The basic principles of anaesthetic management that govern mammalian anaesthesia also apply to birds, although specific anatomical and physiological differences must be considered [4, 9, 10, 21]. Because of the anatomy and structure of the avian respiratory system, even healthy birds may not be properly oxygenated when anaesthetised and placed in dorsal recumbence, so IPPV is recommended [10, 22]. Data on the effects of
Influence of groundwater depth and available soil water on evapotranspiration and plant growth
Renger M.,Wessolek G.
International Agrophysics , 2000,
Abstract: There is a close relationship between available soil water and water consumption as well as plant growth if we assume adequate soil aeration. Transpiration and plant growth increase with an increasing amount of available water, which can be provided either from the soil or from the groundwater, i.e., capillary rise. Interaction between growth and transpiration is based on the stomata regulation of the plant which is involved in both water consumption and photosynthesis. Plants transpire when their stomata are open and at the same time CO2 diffuses into the plant from the atmosphere. These processes are interrupted when stomatas are closed. Using a calibrated simulation model for cropland, grassland, and pine forest, the actual evapotranspiration Eact was determined for various soils and groundwater depth levels. Eact increases in the sequence cropland < grassland < coniferous forest. Results show a strong correlation between the ratio of transpiration (Eact) and water vapour pressure gradient (De) of the air and field measured production of dry matter.
Improving behaviour in self-testing (IBIS): Study on frequency of use, consequences, information needs and use, and quality of currently available consumer information (protocol)
Janaica EJ Grispen, Martine HP Ickenroth, Nanne K de Vries, Geert-Jan Dinant, Gaby Ronda, Trudy van der Weijden
BMC Public Health , 2010, DOI: 10.1186/1471-2458-10-453
Abstract: Mixed methods study with (1) a cross-sectional study consisting of a two-phase Internet-questionnaire, (2) semi-structured interviews with self-testers and consumers who intend to use a self-test, and (3) the assessment of the quality of consumer information of self-tests. The Health Belief Model and the Theory of Planned Behaviour will serve as the theoretical basis for the questionnaires and the interview topic guides.The self-testing area is still in a state of flux and therefore it is expected that self-test use will increase in the future. To the best of our knowledge, this is the first study which combines quantitative and qualitative research to identify consumers' information needs and use concerning self-testing, and the consumers' actual follow-up behaviour based on the self-test result, and simultaneously investigates the quality of the currently available consumer information. The results of this study will be used as an input in developing consumer information on self-testing.A range of self-tests has become available to consumers in the Netherlands and elsewhere [1]. Self-tests are currently available for more than 25 conditions, ranging from infectious diseases to cardiovascular risk factors. Self-tests are not rarely used; 16% of a sample of Dutch Internet users indicated they had ever used at least one self-test in 2006, whereas 17% of those who had never used a self-test indicated they would probably or definitely use one in the future. The five most frequently used self-tests were tests for diabetes, cholesterol, allergies, urinary tract infection, and HIV [1].We defined self-tests as in-vitro tests on body materials such as blood, urine, faeces, or saliva that are initiated by consumers to diagnose a particular disorder or risk factor. In other words, by using a self-test, consumers completely avoid the traditional health care systems. Pregnancy tests, home blood-pressure meters, and monitoring tests, e.g. serum glucose for patients with diabetes
Awareness detection in anaesthesia during otorhino-maxillofacial surgery using bispectral index - monitoring technology  [PDF]
Rado?i? Nade?da N.,Kastratovi? Dragana A.,Tomi? Snje?ana D.,Terzi? Milica K.
Medicinski Pregled , 2012, DOI: 10.2298/mpns1204111r
Abstract: Introduction. Awareness is characterized by intraoperative presence of consciousness and recollecting of the events occurring during general anaesthesia. The study was aimed at detecting awareness during general anaesthesia in otorhino-maxillofacial procedure. Methods. The study is a part of a prospective, phase IV, academic study carried out at the Department for Otorhinolaringology, Clinical Centre of Serbia, and Maxillofacial Surgery. The study was approved by the Ethics Committee of the Clinical Centre of Serbia and performed in accordance with European Union Clinical Trials Directive. The evaluation included 40 patients (T-propofol and Esevofluran group) subjected to different surgical procedures (American Society of Anesthesiologists I-III). Depth of anaesthesia was monitored during surgical procedures according to the hemodynamic parameters (blood pressure, pulse, oxygen saturation, electrocardiography, capnometry). Bispectral index monitoring was applied; however, the insight into the obtained bispectral index values was possible only after the completion of the surgery when the comparison with hemodynamic values was performed. Modified Brice interview was postoperatively applied to the patients in whom awareness was suspected. Results. Based on the hemodynamic parameter values obtained in 40 anesthetized patients, no cases of awareness were expected. After the completion of the surgical procedures, the recorded graphic and numeric bispectral index values obtained in the course of anaesthesia were analyzed. Higher bispectral index values (BIS > 60) were recorded in 1 T-group patient. Conclusion. It is possible to miss an awareness episode without using bispectral index technology monitoring during general anaesthesia in otorhinolaryngology and maxillofacial surgery. Bispectral index monitoring should be the clinical standard in general anaesthesia.
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