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BACKGROUND: Hypotension is common during spinal anesthesia for cesarean delivery. Preventive strategies include fluid loading and phenylephrine. We hypothesized that if prophylactic phenylephrine infusion is used, omission of fluid loading would be non-inferior to fluid co-loading in maintaining cardiac output. We assumed that if there was a difference, the increase in cardiac output would be greater in the no-loading than in the co-loading group. METHODS: Term pregnant women scheduled for elective cesarean delivery were randomized to receive 1 L crystalloid co-loading or maintenance fluids only. Phenylephrine was titrated to maintain blood pressure. Changes in cardiac output following spinal anesthesia were the primary outcome. The study was powered as a non-inferiority trial, allowing the no-loading arm to have a 50% greater change in cardiac output. Heart rate, dose of phenylephrine, occurrence of nausea and vomiting, Apgar scores and neonatal acid base status were secondary outcomes. RESULTS: Data from 63 women were analyzed. In contrast to our hypothesis, there was 33% less increase in cardiac output with no loading (ratio 0.67, 95% CI 0.15 to 1.36), and 60% greater reduction of cardiac output with no loading (ratio 1.6, 95% CI 1.0 to 2.7). Total dose of phenylephrine was higher in the no-loading group. There may be a less favorable neonatal acid base status without volume loading. CONCLUSION: Omission of crystalloid co-loading leads to a decrease in cardiac output which has a potentially unfavorable impact on neonatal acid base status. We conclude that crystalloid co-loading may be useful in the presence of phenylephrine infusion.
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Raquianestesia , Cesárea , Soluções Cristaloides , Hipotensão , Fenilefrina , Humanos , Feminino , Cesárea/métodos , Gravidez , Soluções Cristaloides/administração & dosagem , Soluções Cristaloides/uso terapêutico , Método Duplo-Cego , Hipotensão/prevenção & controle , Hipotensão/etiologia , Adulto , Raquianestesia/métodos , Raquianestesia/efeitos adversos , Fenilefrina/uso terapêutico , Anestesia Obstétrica/métodos , Anestesia Obstétrica/efeitos adversos , Procedimentos Cirúrgicos Eletivos , Débito Cardíaco/efeitos dos fármacos , Vasoconstritores/uso terapêuticoRESUMO
INTRODUCTION: Fertility problems are the main reasons for culling dairy cows. Diseases of the female genital tract are also often the cause of antibiotic or hormonal treatments in bovine practices. The use of medicinal plants could expand the available therapeutics. The aim of the work was to analyze historical literature before the introduction of antibiotics in veterinary reproductive medicine. Five books in German language, published in Germany and Switzerland between 1878 and 1921, and one handwritten therapy booklet by the rural veterinarian Carl Ammann-Honegger (1879-1960) were systematically examined regarding the descriptions (AW) on gynecological diseases. The herbal and additional ingredients of the recipe, the target animal species, the type of administration and the indication were recorded in detail for each AW. The six literature sources contained a total of 103 AW (79 administered orally, 13 locally, and 11 both orally and locally). Almost two thirds of the AW (61) were based on a mixture of different plants (two to seven plants), and one third of the AW (31) on a single plant. A total of 55 plants were recorded. The most frequently mentioned medical plants were plants of the genus Juniperus (J. communis L. (19 AW), J. sabina L. (13 AW)) and Linum usitatissimum L. (18 AW), Matricaria chamomilla L. (13 AW) and Gentiana lutea L. (12 AW). The treatment of the Retentio secundinarum was the most frequently mentioned indication (44 AW), followed by parturition preparation (17 AW) and endometritis treatment (15 AW). The most frequently recorded plants can be divided based on their ingredients and their effect into (a) energy- and protein-rich forage plants, (b) generally appetizing, digestive- and metabolism-enhancing plants, (c) medical plants with a specific gynecological organotrophic effect and (d) according to current knowledge, predominantly toxic plants. Besides the antimicrobial active immunity to defence against bacterial infections, a stable barrier funcion of the endometrium contributes to uterine health. The plants classified under (a) - (c) have at least the potential for a positive effect on the immune system and the endometrial barrier function and thus contribute indirectly to the uterine health.
INTRODUCTION: Les problèmes de fertilité sont les principales raisons de la mise à la réforme des vaches laitières. Les maladies de l'appareil génital femelle sont également souvent à l'origine de traitements antibiotiques ou hormonaux dans les pratiques bovines. L'utilisation de plantes médicinales pourrait élargir les thérapeutiques disponibles. L'objectif de ce travail était d'analyser la littérature historique avant l'introduction des antibiotiques en médecine de la reproduction vétérinaire. Cinq livres en langue allemande, publiés en Allemagne et en Suisse entre 1878 et 1921, et un livret thérapeutique écrit à la main par le vétérinaire rural Carl Ammann-Honegger (18791960) ont été systématiquement examinés en ce qui concerne les descriptions d'utilisation (AW) sur les maladies gynécologiques. Les herbes et les ingrédients supplémentaires de la recette, l'espèce animale cible, le type d'administration et l'indication ont été enregistrés en détail pour chaque AW. Les six sources de littérature contenaient un total de 103 AW (79 administrées par voie orale, 13 par voie locale et 11 par voie orale et locale). Près de deux tiers des AW (61) étaient basés sur un mélange de différentes plantes (deux à sept plantes), et un tiers des AW (31) sur une seule plante. Au total, 55 plantes ont été enregistrées. Les plantes médicinales les plus fréquemment mentionnées étaient les plantes du genre Juniperus (J. communis L. (19 AW), J. sabina L. (13 AW)) et Linum usitatissimum L. (18 AW), Matricaria chamomilla L. (13 AW) et Gentiana lutea L. (12 AW). Le traitement du Retentio secundinarum a été l>indication la plus fréquemment mentionnée (44 AW), suivie de la préparation à la parturition (17 AW) et du traitement de l>endométrite (15 AW). Les plantes les plus fréquemment enregistrées peuvent être divisées, en fonction de leurs composants et de leurs effets, en (a) plantes fourragères riches en énergie et en protéines, (b) plantes généralement appétissantes, favorisant la digestion et le métabolisme, (c) plantes médicinales ayant un effet organotropique gynécologique spécifique et (d) selon les connaissances actuelles, plantes principalement toxiques. Outre l'effet antimicrobien, une capacité de défense stable de l'endomètre contribue à la santé utérine. Les plantes classées sous (a) - (c) ont au moins le potentiel d'un effet positif sur le système immunitaire et la fonction de défense de l'endomètre et contribuent ainsi indirectement à la santé utérine.
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Anti-Infecciosos , Doenças dos Bovinos , Plantas Medicinais , Animais , Anti-Infecciosos/uso terapêutico , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Feminino , Fertilidade , Alemanha , Fitoterapia/veterináriaRESUMO
Throughout Africa, lions are thought to have experienced dramatic population decline and range contraction. The greatest declines are likely occurring in human-dominated landscapes where reliably estimating lion populations is particularly challenging. By adapting a method that has thus far only been applied to animals that are habituated to vehicles, we estimate lion density in two community areas in Kenya's South Rift, located more than 100 km from the nearest protected area (PA). More specifically, we conducted an 89-day survey using unstructured spatial sampling coupled with playbacks, a commonly used field technique, and estimated lion density using spatial capture-recapture (SCR) models. Our estimated density of 5.9 lions over the age of 1 year per 100 km2 compares favorably with many PAs and suggests that this is a key lion population that could be crucial for connectivity across the wider landscape. We discuss the possible mechanisms supporting this density and demonstrate how rigorous field methods combined with robust analyses can produce reliable population estimates within human-dominated landscapes.
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BACKGROUND: Several methods have been proposed to measure cerebrovascular autoregulation (CA) in traumatic brain injury (TBI), but the lack of a gold standard and the absence of prospective clinical data on risks, impact on care and outcomes of implementation of CA-guided management lead to uncertainty. AIM: To formulate statements using a Delphi consensus approach employing a group of expert clinicians, that reflect current knowledge of CA, aspects that can be implemented in TBI management and CA research priorities. METHODS: A group of 25 international academic experts with clinical expertise in the management of adult severe TBI patients participated in this consensus process. Seventy-seven statements and multiple-choice questions were submitted to the group in two online surveys, followed by a face-to-face meeting and a third online survey. Participants received feedback on average scores and the rationale for resubmission or rephrasing of statements. Consensus on a statement was defined as agreement of more than 75% of participants. RESULTS: Consensus amongst participants was achieved on the importance of CA status in adult severe TBI pathophysiology, the dynamic non-binary nature of CA impairment, its association with outcome and the inadvisability of employing universal and absolute cerebral perfusion pressure targets. Consensus could not be reached on the accuracy, reliability and validation of any current CA assessment method. There was also no consensus on how to implement CA information in clinical management protocols, reflecting insufficient clinical evidence. CONCLUSION: The Delphi process resulted in 25 consensus statements addressing the pathophysiology of impaired CA, and its impact on cerebral perfusion pressure targets and outcome. A research agenda was proposed emphasizing the need for better validated CA assessment methods as well as the focused investigation of the application of CA-guided management in clinical care using prospective safety, feasibility and efficacy studies.
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Lesões Encefálicas Traumáticas , Adulto , Lesões Encefálicas Traumáticas/terapia , Circulação Cerebrovascular , Consenso , Técnica Delphi , Homeostase , Humanos , Estudos Prospectivos , Reprodutibilidade dos TestesRESUMO
OBJECTIVES: Retrospective data from patients with severe traumatic brain injury (TBI) indicate that deviation from the continuously calculated pressure reactivity-based "optimal" cerebral perfusion pressure (CPPopt) is associated with worse patient outcome. The objective of this study was to assess the relationship between prospectively collected CPPopt data and patient outcome after TBI. METHODS: We prospectively collected intracranial pressure (ICP) monitoring data from 231 patients with severe TBI at Addenbrooke's Hospital, UK. Uncleaned arterial blood pressure and ICP signals were recording using ICM+® software on dedicated bedside computers. CPPopt was determined using an automatic curve fitting procedure of the relationship between pressure reactivity index (PRx) and CPP using a 4-h window, as previously described. The difference between an instantaneous CPP value and its corresponding CPPopt value was denoted every minute as ΔCPPopt. A negative ΔCPPopt that was associated with impaired PRx (>+0.15) was denoted as being below the lower limit of reactivity (LLR). Glasgow Outcome Scale (GOS) score was assessed at 6 months post-ictus. RESULTS: When ΔCPPopt was plotted against PRx and stratified by GOS groupings, data belonging to patients with a more unfavourable outcome had a U-shaped curve that shifted upwards. More time spent with a ΔCPPopt value below the LLR was positively associated with mortality (area under the receiver operating characteristic curve = 0.76 [0.68-0.84]). CONCLUSIONS: In a recent cohort of patients with severe TBI, the time spent with a CPP below the CPPopt-derived LLR is related to mortality. Despite aggressive CPP- and ICP-oriented therapies, TBI patients with a fatal outcome spend a significant amount of time with a CPP below their individualised CPPopt, indicating a possible therapeutic target.
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Pressão Arterial , Lesões Encefálicas Traumáticas/terapia , Circulação Cerebrovascular , Pressão Intracraniana , Adulto , Estudos de Coortes , Gerenciamento Clínico , Feminino , Escala de Resultado de Glasgow , Humanos , Masculino , Monitorização Fisiológica , Estudos Retrospectivos , Índices de Gravidade do TraumaRESUMO
BACKGROUND: Carbetocin is a synthetic oxytocin-analogue, which should be administered as bolus according to manufacturer's recommendations. A higher speed of oxytocin administration leads to increased cardiovascular side-effects. It is unclear whether carbetocin administration as short infusion has the same efficacy on uterine tone compared with bolus administration and whether haemodynamic parameters differ. METHODS: In this randomized, double-blind, non-inferiority trial, women undergoing planned or unplanned Caesarean section (CS) under regional anaesthesia received a bolus and a short infusion, only one of which contained carbetocin 100 mcg (double dummy). Obstetricians quantified uterine tone two, three, five and 10 min after cord-clamping by manual palpation using a linear analogue scale from 0 to 100. We evaluated whether the lower limit of the 95% CI of the difference in maximum uterine tone within the first five min after cord-clamping did not include the pre-specified non-inferiority limit of -10. RESULTS: Between December 2014 and November 2015, 69 patients were randomized to receive carbetocin as bolus and 71 to receive it as short infusion. Maximal uterine tone was 89 in the bolus and 88 in the short infusion group (mean difference -1.3, 95% CI -5.7 to 3.1). Bp, calculated blood loss, use of additional uterotonics, and side-effects were comparable. CONCLUSIONS: Administration of carbetocin as short infusion does not compromise uterine tone and has similar cardiovascular side-effects as a slow i.v. bolus. In accordance with current recommendations for oxytocin, carbetocin can safely be administered as short -infusion during planned or unplanned CS. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT02221531 and www.kofam.ch SNCTP000001197.
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Cesárea/métodos , Ocitócicos/administração & dosagem , Ocitócicos/uso terapêutico , Ocitocina/análogos & derivados , Adulto , Método Duplo-Cego , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Infusões Intravenosas , Injeções Intravenosas , Ocitócicos/efeitos adversos , Ocitocina/administração & dosagem , Ocitocina/efeitos adversos , Ocitocina/uso terapêutico , Hemorragia Pós-Parto/prevenção & controle , Gravidez , Resultado do Tratamento , Contração Uterina/efeitos dos fármacosRESUMO
Intracranial pressure (ICP) is governed by volumes of intracranial blood, cerebrospinal fluid, and brain tissue. Expansion of any of these volumes will trigger compensatory changes in the other compartments, resulting in initially limited change in ICP. Due to the rigid skull, once compensatory mechanisms are exhausted, ICP rises very rapidly. Intracranial hypertension is associated with unfavorable outcome in brain-injured patients. This chapter discusses the pathophysiology of raised ICP, as well as typical waveforms, monitoring techniques, and clinical management. The dynamics of ICP are more important than the absolute value at any given time point, but mean ICP exceeding 20-25mmHg is usually treated aggressively. Algorithms based on data from patients with traumatic brain injury are applied also in other conditions. However, an understanding of the underlying pathophysiology allows adaptation of therapies to other pathologies. Typically, a three-staged approach is used, starting with restoration of systemic physiology, sedation, and analgesia. If these measures are insufficient, surgical options, such as drainage of cerebrospinal fluid or evacuation of mass lesions, are considered. In the absence of surgical options, stage 2 treatments are initiated, consisting of either mannitol or hypertonic saline. If these measures are insufficient, stage 3 therapies include hypothermia, metabolic suppression, or craniectomy.
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Lesões Encefálicas Traumáticas/fisiopatologia , Hipertensão Intracraniana/fisiopatologia , Pressão Intracraniana/fisiologia , Lesões Encefálicas Traumáticas/complicações , Humanos , Hipertensão Intracraniana/etiologiaRESUMO
BACKGROUND: Data regarding immunomodulatory effects of parenteral n-3 fatty acids in sepsis are conflicting. In this study, the effect of administration of parenteral n-3 fatty acids on markers of brain injury, incidence of sepsis-associated delirium, and inflammatory mediators in septic patients was investigated. METHODS: Fifty patients with sepsis were randomized to receive either 2 ml/kg/day of a lipid emulsion containing highly refined fish oil (equivalent to n-3 fatty acids 0.12 mg/kg/day) during 7 days after admission to the intensive care unit or standard treatment. Markers of brain injury and inflammatory mediators were measured on days 1, 2, 3 and 7. Assessment for sepsis-associated delirium was performed daily. The primary outcome was the difference in S-100ß from baseline to peak level between both the intervention and the control group, compared by t-test. Changes of all markers over time were explored in both groups, fitting a generalized estimating equations model. RESULTS: Mean difference in change of S-100ß from baseline to peak level was 0.34 (95% CI: -0.18-0.85) between the intervention and control group, respectively (P = 0.19). We found no difference in plasma levels of S-100ß, neuron-specific enolase, interleukin (IL)-6, IL-8, IL-10, and C-reactive protein between groups over time. Incidence of sepsis-associated delirium was 75% in the intervention and 71% in the control groups (risk difference 4%, 95% CI -24-31%, P = 0.796). CONCLUSION: Administration of n-3 fatty acids did not affect markers of brain injury, incidence of sepsis-associated delirium, and inflammatory mediators in septic patients.
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Dano Encefálico Crônico/prevenção & controle , Delírio/prevenção & controle , Ácidos Graxos Ômega-3/uso terapêutico , Óleos de Peixe/uso terapêutico , Sepse/complicações , Idoso , Biomarcadores , Dano Encefálico Crônico/sangue , Dano Encefálico Crônico/etiologia , Proteína C-Reativa/análise , Delírio/sangue , Delírio/etiologia , Emulsões , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/efeitos adversos , Ácidos Graxos Ômega-3/farmacologia , Feminino , Óleos de Peixe/administração & dosagem , Óleos de Peixe/efeitos adversos , Óleos de Peixe/farmacologia , Seguimentos , Humanos , Hipertrigliceridemia/induzido quimicamente , Mediadores da Inflamação/sangue , Interleucinas/sangue , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Fosfopiruvato Hidratase/sangue , Subunidade beta da Proteína Ligante de Cálcio S100/sangue , Sepse/sangueRESUMO
The impact of fatigue is seen not only in its effect on job performance of haul truck operators but also on the health of the operator and the productivity at the mine site. Its impact can even extend outside of the mine site to the health and well-being of the surrounding community (Fourie et al., 2010). In this paper, a case study of a small surface mining organization is presented. The goal is to highlight the fatigue risk management system implemented at the studied mine site. Mine safety personnel who were interviewed discuss the changes made to the infrastructure of the mine, to administrative areas such as the number of shifts and the use of vacation time, as well as the implementation of new technology into haulage vehicles. This paper reviews how these changes are supported in the research literature.
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Fraud is as old as Mankind. There are an enormous number of historical documents which show the interaction between truth and untruth; therefore it is not really surprising that the prevalence of publication discrepancies is increasing. More surprising is that new cases especially in the medical field generate such a huge astonishment. In financial mathematics a statistical tool for detection of fraud is known which uses the knowledge of Newcomb and Benford regarding the distribution of natural numbers. This distribution is not equal and lower numbers are more likely to be detected compared to higher ones. In this investigation all numbers contained in the blinded abstracts of the 2009 annual meeting of the Swiss Society of Anesthesia and Resuscitation (SGAR) were recorded and analyzed regarding the distribution. A manipulated abstract was also included in the investigation. The χ(2)-test was used to determine statistical differences between expected and observed counts of numbers. There was also a faked abstract integrated in the investigation. A p<0.05 was considered significant. The distribution of the 1,800 numbers in the 77 submitted abstracts followed Benford's law. The manipulated abstract was detected by statistical means (difference in expected versus observed p<0.05). Statistics cannot prove whether the content is true or not but can give some serious hints to look into the details in such conspicuous material. These are the first results of a test for the distribution of numbers presented in medical research.
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Má Conduta Científica/estatística & dados numéricos , Algoritmos , Anestesiologia/normas , Animais , Coagulação Sanguínea , Testes de Coagulação Sanguínea , Interpretação Estatística de Dados , Humanos , Editoração/normas , SuínosRESUMO
BACKGROUND: Age is an important risk factor for perioperative cerebral complications such as stroke, postoperative cognitive dysfunction, and delirium. We explored the hypothesis that intraoperative cerebrovascular autoregulation is less efficient and brain tissue oxygenation lower in elderly patients, thus, increasing the vulnerability of elderly brains to systemic insults such as hypotension. METHODS: We monitored intraoperative cerebral perfusion in 50 patients aged 18-40 and 77 patients >65 yr at two Swiss university hospitals. Mean arterial pressure (MAP) was measured continuously using a plethysmographic method. An index of cerebrovascular autoregulation (Mx) was calculated based on changes in transcranial Doppler flow velocity due to changes in MAP. Cerebral oxygenation was assessed by the tissue oxygenation index (TOI) using near-infrared spectroscopy. End-tidal CO2, O2, and sevoflurane concentrations and peripheral oxygen saturation were recorded continuously. Standardized anaesthesia was administered in all patients (thiopental, sevoflurane, fentanyl, atracurium). RESULTS: Autoregulation was less efficient in patients aged >65 yr [by 0.10 (se 0.04; P=0.020)] in a multivariable linear regression analysis. This difference was not attributable to differences in MAP, end-tidal CO2, or higher doses of sevoflurane. TOI was not significantly associated with age, sevoflurane dose, or Mx but increased with increasing flow velocity [by 0.09 (se 0.04; P=0.028)] and increasing MAP [by 0.11 (se 0.05; P=0.043)]. CONCLUSIONS: Our results do not support the hypothesis that older patients' brains are more vulnerable to systemic insults. The difference of autoregulation between the two groups was small and most likely clinically insignificant.
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Encéfalo/metabolismo , Circulação Cerebrovascular , Homeostase , Monitorização Intraoperatória/métodos , Oxigênio/metabolismo , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Encéfalo/irrigação sanguínea , Dióxido de Carbono/metabolismo , Humanos , Fluxometria por Laser-Doppler/métodos , Masculino , Adulto JovemRESUMO
A variety of directional control-response relationships are currently found in mining equipment. Two experiments were conducted in a virtual environment to determine optimal direction control-response relationships in a wide variety of circumstances. Direction errors were measured as a function of control orientation (horizontal or vertical), location (left, front, right) and directional control-response relationships. The results confirm that the principles of consistent direction and visual field compatibility are applicable to the majority of situations. An exception is that fewer direction errors were observed when an upward movement of a horizontal lever or movement of a vertical lever away from the participants caused extension (lengthening) of the controlled device, regardless of whether the direction of movement of the control is consistent with the direction in which the extension occurs. Further, both the control of slew by horizontally oriented controls and the control of device movements in a frontal plane by the perpendicular movements of vertical levers were associated with relatively high rates of directional errors, regardless of the directional control-response relationship, and these situations should be avoided. STATEMENT OF RELEVANCE: The results are particularly applicable to the design of mining equipment such as drilling and bolting machines, and have been incorporated into MDG35.1 Guideline for bolting & drilling plant in mines (Industry & Investment NSW, 2010). The results are also relevant to the design of any equipment where vertical or horizontal levers are used to control the movement of equipment appendages, e.g. cranes mounted to mobile equipment and the like.
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Desenho de Equipamento , Sistemas Homem-Máquina , Mineração/instrumentação , Análise e Desempenho de Tarefas , Adulto , Análise de Variância , Simulação por Computador , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mineração/normas , Exposição Ocupacional , Saúde Ocupacional , Orientação , Desempenho Psicomotor , Queensland , Gestão da Segurança , Percepção Espacial , Campos Visuais , Adulto JovemRESUMO
BACKGROUND: Spinal anaesthesia (SA) has high success rates. However, inadequate block after SA has been reported even in the absence of technical problems. Various mechanisms for failed SA (FSA) have been proposed, but reports of cerebrospinal fluid (CSF) concentrations of local anaesthetics (LA) after FSA are scarce. We report lumbar CSF concentrations of bupivacaine in 20 patients in whom adequate block after subarachnoid injection failed to develop. METHODS: All patients with inadequate block after subarachnoid injection of plain bupivacaine 0.5% and in whom a second subarachnoid injection of LA was to be performed as a rescue technique were eligible for entry into this study. A CSF sample was withdrawn immediately before injection of the second dose of LA. Patients in whom failure was obviously due to technical problems or inadequate dosage were excluded. Bupivacaine concentrations were assessed with high-performance liquid chromatography. RESULTS: During the study period of 15 months, 2600 spinal anaesthetics were performed. The failure rate was 2.7% (71 patients). In 20 patients (0.77%), CSF concentrations of bupivacaine were determined, which ranged from 3.36 to 1020 microg ml(-1). CONCLUSIONS: Inadequate CSF concentration of LA is a common reason for FSA. However, in 12 of our 20 patients, concentrations were above 73 microg ml(-1), a concentration that should lead to an adequate block. In these patients, maldistribution of bupivacaine could be responsible for FSA. In view of the absence of sufficient block, despite adequate lumbar CSF concentrations of bupivacaine, concerns about neurotoxicity with repeat injections may be warranted.
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Raquianestesia/métodos , Anestésicos Locais/líquido cefalorraquidiano , Bupivacaína/líquido cefalorraquidiano , Idoso , Idoso de 80 Anos ou mais , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Humanos , Região Lombossacral , Masculino , Pessoa de Meia-Idade , Sensação/efeitos dos fármacos , Punção Espinal , Falha de TratamentoRESUMO
BACKGROUND: Data on bupivacaine concentrations in the cerebral spinal fluid (CSF) during spinal anaesthesia are scarce. The purpose of this study was to determine the concentration of bupivacaine in the lumbar CSF of patients with an adequate level of spinal anaesthesia after injection of plain bupivacaine 0.5%. METHODS: Sixty patients with an adequate level of spinal block after standardized administration of plain bupivacaine 20 mg in men and of 17.5 mg in women were studied. To measure the CSF bupivacaine concentration, we performed a second lumbar spinal puncture and obtained a CSF sample at a randomized time point 5-45 min after the bupivacaine injection. In addition, we calculated the half-life of bupivacaine in the CSF and tested the hypothesis that the level of spinal block is related to the lumbar CSF bupivacaine concentration. RESULTS: Men and women had CSF bupivacaine concentrations ranging from 95.4 to 773.0 microg ml(-1) (median 242.4 microg ml(-1)) and from 25.9 to 781.0 microg ml(-1) (median 187.6 microg ml(-1)), respectively. The large variability of bupivacaine concentrations obtained at similar times after subarachnoid administration made calculation of a meaningful half-life of bupivacaine in CSF impossible. There was no association between CSF bupivacaine concentration and spinal block level, and CSF bupivacaine concentrations for the same spinal block level differed between patients by six-fold. CONCLUSIONS: There is a large variability of CSF bupivacaine concentrations in patients with an adequate level of spinal anaesthesia.
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Raquianestesia/métodos , Anestésicos Locais/líquido cefalorraquidiano , Bupivacaína/líquido cefalorraquidiano , Idoso , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Meia-Vida , Humanos , Região Lombossacral , Masculino , Pessoa de Meia-Idade , Movimento/fisiologia , Postura/fisiologia , Sensação/efeitos dos fármacos , Fatores Sexuais , Punção EspinalRESUMO
Data on the cerebrovascular effects of catecholamines after head injury are difficult both to interpret and to compare. Diverse parameters with regard to brain trauma animal models, methods of determining the effects on the cerebral blood flow and metabolism and choice of end-points have been used. Many studies investigate the cerebrovascular effects of catecholamines over a range of cerebral perfusion pressures above the range recommended by current guidelines. The relationship between patient outcome and the use of a specific substance to improve cerebral perfusion has not been investigated. Dopamine, norepinephrine and phenylephrine all seem to increase cerebral blood flow in various animal models and in patients. The data suggest that norepinephrine may be the most predictable. It is associated with an improved restoration of global and regional oxygenation when compared to dopamine. Dopamine has been associated with an increase in brain oedema. There is further evidence that dopamine has many disadvantages in critically ill patients due to its ability to suppress circulating concentrations of most anterior pituitary-dependent hormones. Both aspects would further discourage its use. Data on phenylephrine are scarce. It has been associated with increased intracranial pressure and a failure to improve cerebral oxygenation despite markedly improved cerebral perfusion pressure. For all other catecholamines and related substances there are insufficient data on the cerebrovascular effects after head injury. This suggests that norepinephrine may be the catecholamine that is the most suitable substance to maintain or restore adequate cerebral perfusion. The data, however, are insufficient to formulate a guideline.
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Lesões Encefálicas/metabolismo , Catecolaminas/metabolismo , Circulação Cerebrovascular , Animais , Encéfalo/metabolismo , Edema Encefálico/patologia , Dopamina/metabolismo , Humanos , Pressão Intracraniana , Modelos Animais , Modelos Biológicos , Norepinefrina/metabolismo , Oxigênio/metabolismo , Perfusão , PressãoRESUMO
INTRODUCTION: In sepsis the brain is frequently affected although there is no infection of the CNS (septic encephalopathy). One possible cause of septic encephalopathy is failure of the blood-brain barrier. Brain edema has been documented in animal models of sepsis. Aggressive fluid resuscitation in the early course of sepsis improves survival and is standard practice. We hypothesized that aggressive fluid administration will increase intracranial pressure (ICP) and may cause critical reductions in cerebral perfusion pressure (CPP). MATERIALS AND METHODS: Patients with sepsis were investigated daily on up to four consecutive days in the intensive care unit. Mean arterial blood pressure (MAP) and blood flow velocity in the middle cerebral artery were monitored for one hour each day. ICP was calculated non-invasively from MAP and flow velocity data. S-100beta was determined daily. FINDINGS: Fifty-two measurements were performed in 16 patients. ICP could be determined in 45 measurements in 15 patients. Seven patients had an ICP > 15 mmHg and 11 patients had a CPP < 60 mmHg on at least 1 day. We found no significant correlation between ICP and fluid administration, but low CPP was significantly correlated with elevated S-100beta (r = -0.47, p = 0.001). CONCLUSIONS: Further research is needed to determine the role of ICP/CPP monitoring in patients with sepsis.
Assuntos
Circulação Cerebrovascular/fisiologia , Pressão Intracraniana/fisiologia , Sepse/fisiopatologia , Idoso , Pressão Sanguínea/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fluxo Pulsátil/fisiologia , Estatísticas não Paramétricas , Ultrassonografia Doppler Transcraniana/métodosRESUMO
Oilseed press-cake (PC) is proposed as a novel material for the removal of hydrophobic organic pollutants (HOPs) from water. Sorption of the pesticides carbaryl, atrazine and parathion, with log K(ow) being, respectively, 1.59, 2.55 and 3.83, was demonstrated using cold-pressed rapeseed (Brassica napus), moringa (Moringa oleifera) and soybean (Glycine max) PCs. Linear sorption isotherms have been observed. The partition coefficient of carbaryl, atrazine and parathion using rapeseed PC were determined to be 0.028+/-0.003, 0.144+/-0.003 and 2.52+/-0.24 L/g, respectively. Partition studies of atrazine in PC-extracted oil and defatted PC showed that the sorption mechanism is mainly through absorption in the residual oil in the PC, whereas adsorption on the PC matrix is quantitatively much less significant. It was also shown that the oil content of the PC is not the only parameter determining the partitioning of pesticides. Indeed, sorption using ground seeds was very weak, as demonstrated by the low partition and mass transfer coefficients. This may be due to cell structures blocking the pesticide diffusion to the oil-containing structures within the seeds, while for PC oil they are present in the form of small (10 microm) droplets trapped within the hydrophilic PC matrix, thus presenting less resistance for mass transfer.
Assuntos
Atrazina/química , Óleos de Plantas/química , Resíduos , Poluentes Químicos da Água/química , Absorção , Brassica napus , Carbaril/química , Moringa oleifera , Paration/química , Praguicidas/química , Sementes , Glycine max , Purificação da Água/métodosRESUMO
We determined the accuracy of two transcutaneous carbon dioxide monitoring systems (SenTec Digital Monitor with V-Sign Sensor and TOSCA 500 with TOSCA Sensor 92) for the measurement of single values and trends in the arterial partial pressure of carbon dioxide in 122 adult patients during major surgery and in 50 adult patients in the intensive care unit. One or several paired measurements were performed in each patient. The first measurement was used to determine the accuracy of a single value of transcutaneous carbon dioxide; the difference between the first and the last measurements was used to analyse the accuracy and to track trends. We defined a 95% limit of agreement of Assuntos
Monitorização Transcutânea dos Gases Sanguíneos/métodos
, Dióxido de Carbono/sangue
, Monitorização Intraoperatória/métodos
, Idoso
, Monitorização Transcutânea dos Gases Sanguíneos/instrumentação
, Cuidados Críticos/métodos
, Feminino
, Humanos
, Masculino
, Pessoa de Meia-Idade
, Monitorização Intraoperatória/instrumentação
, Monitorização Fisiológica/métodos
, Pressão Parcial
, Estudos Prospectivos
, Reprodutibilidade dos Testes