Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.

Made available in DSpace on 2015-04-09T12:28:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-01-16Bitstream added on 2015-04-09T12:47:50Z : No. of bitstreams: 1 000815198.pdf: 1152828 bytes, checksum: bf552d4b2ff531afe935d24b0d37090d (MD5) / A sepse é uma síndrome de caráter multifatorial e com consequências graves para sobrevida e para os custos de tratamento em cães. Neste contexto a gastroenterite é um representante importante desta síndrome inflamatória de associação infecciosa no campo das urgências veterinárias. Este estudo unicêntrico, prospectivo e de coorte apresentou como objetivo fundamental identificar as variáveis prognósticas associadas com a sobrevivência a curto e médio prazo de 56 cães com gastroenterite, atendidos como urgências e hospitalizados para cuidados intensivos. Foram coletados dados fisiológicos e laboratoriais no momento da admissão de urgência dos pacientes (T0) e 24 horas depois (T24). Desta forma, foram encontradas as relações destes parâmetros com a sobrevivência ou a mortalidade em 24 horas, e aos 7, 30 e 60 dias pós ingresso. Com os resultados obtidos, foram criadas árvores de decisão empregadas na estratificação, previsão e identificação de todas as interações possíveis. A gravidade do quadro clínico, laboratorial e dos antecedentes históricos prediz a mortalidade de pacientes caninos com gastroenterite; e os doentes diagnosticados com parvovirose ou gastroenterite hemorrágica, classificados em sepse grave ou em choque séptico, possuem maior mortalidade tanto às 24 horas quanto aos 7, 30 e 60 dias após atendimento. A queda do potencial de transporte de oxigênio, do potencial oncótico e a alteração metabólica em nível celular foram determinantes no prognóstico dos pacientes, representados respectivamente pelo alto poder prognóstico das variações em 24 horas do hematócrito, das proteínas totais e do lactato sérico, bem como a presença de vasoconstrição periférica grave 24 horas após o início do tratamento, demonstrada pelo maior escore de vasoconstrição. Deste modo, pretendeu-se com este estudo, possibilitar o conhecimento aos Médicos Veterinários de ... / Sepsis is a multifactorial syndrome with serious consequences for survival and costs of treatment in dogs. In this context gastroenteritis is an important representative of this inflammatory syndrome infectious association in the veterinary emergencies area. This single-center, prospective cohort study presented as a fundamental objective to identify the prognostic variables associated with survival in the short and medium term of 56 dogs with gastroenteritis treated in emergency and critical care hospital. Physiological and laboratory datas were collected on admission of emergency patients ( T0 ) and 24 hours later ( T24 ). Thus, the relationship between these parameters and the survival or mortality in 24 hours, and at 7, 30 and 60 days after admission were found. With the results, decision trees used in the stratification, prediction and identification of all possible interactions were created. The severity of the clinical, laboratory findings and historical background predicts mortality in canine patients with gastroenteritis , and patients diagnosed with parvovirus or hemorrhagic gastroenteritis, ranked in severe sepsis or septic shock, have higher mortality both at 24 hours as at 7, 30 and 60 days after treatment. The fall of potential oxygen transport, the oncotic potential and metabolic changes at the cellular level were determining the prognosis of patients, respectively represented by the high prognostic power of variations within 24 hours of hematocrit, total protein and lactate as well as presence of severe peripheral vasoconstriction 24 hours after initiation of treatment, as demonstrated by scores greater vasoconstriction. Thus, it is intended with this study, getting familiar to veterinarians to predict survival in dogs with gastroenteritis based on simple parameters, low cost and easy implementation

Orientador: Áureo Evangelista Santana / Coorientador: Paola Castro Moraes / Banca: José Luiz Laus / Banca: Mirela Tinucci Costa / Banca: Márcio Antônio Brunetto / Banca: Rodrigo Cardoso Rabelo / Resumo: A sepse é uma síndrome de caráter multifatorial e com consequências graves para sobrevida e para os custos de tratamento em cães. Neste contexto a gastroenterite é um representante importante desta síndrome inflamatória de associação infecciosa no campo das urgências veterinárias. Este estudo unicêntrico, prospectivo e de coorte apresentou como objetivo fundamental identificar as variáveis prognósticas associadas com a sobrevivência a curto e médio prazo de 56 cães com gastroenterite, atendidos como urgências e hospitalizados para cuidados intensivos. Foram coletados dados fisiológicos e laboratoriais no momento da admissão de urgência dos pacientes (T0) e 24 horas depois (T24). Desta forma, foram encontradas as relações destes parâmetros com a sobrevivência ou a mortalidade em 24 horas, e aos 7, 30 e 60 dias pós ingresso. Com os resultados obtidos, foram criadas árvores de decisão empregadas na estratificação, previsão e identificação de todas as interações possíveis. A gravidade do quadro clínico, laboratorial e dos antecedentes históricos prediz a mortalidade de pacientes caninos com gastroenterite; e os doentes diagnosticados com parvovirose ou gastroenterite hemorrágica, classificados em sepse grave ou em choque séptico, possuem maior mortalidade tanto às 24 horas quanto aos 7, 30 e 60 dias após atendimento. A queda do potencial de transporte de oxigênio, do potencial oncótico e a alteração metabólica em nível celular foram determinantes no prognóstico dos pacientes, representados respectivamente pelo alto poder prognóstico das variações em 24 horas do hematócrito, das proteínas totais e do lactato sérico, bem como a presença de vasoconstrição periférica grave 24 horas após o início do tratamento, demonstrada pelo maior escore de vasoconstrição. Deste modo, pretendeu-se com este estudo, possibilitar o conhecimento aos Médicos Veterinários de ... / Abstract: Sepsis is a multifactorial syndrome with serious consequences for survival and costs of treatment in dogs. In this context gastroenteritis is an important representative of this inflammatory syndrome infectious association in the veterinary emergencies area. This single-center, prospective cohort study presented as a fundamental objective to identify the prognostic variables associated with survival in the short and medium term of 56 dogs with gastroenteritis treated in emergency and critical care hospital. Physiological and laboratory datas were collected on admission of emergency patients ( T0 ) and 24 hours later ( T24 ). Thus, the relationship between these parameters and the survival or mortality in 24 hours, and at 7, 30 and 60 days after admission were found. With the results, decision trees used in the stratification, prediction and identification of all possible interactions were created. The severity of the clinical, laboratory findings and historical background predicts mortality in canine patients with gastroenteritis , and patients diagnosed with parvovirus or hemorrhagic gastroenteritis, ranked in severe sepsis or septic shock, have higher mortality both at 24 hours as at 7, 30 and 60 days after treatment. The fall of potential oxygen transport, the oncotic potential and metabolic changes at the cellular level were determining the prognosis of patients, respectively represented by the high prognostic power of variations within 24 hours of hematocrit, total protein and lactate as well as presence of severe peripheral vasoconstriction 24 hours after initiation of treatment, as demonstrated by scores greater vasoconstriction. Thus, it is intended with this study, getting familiar to veterinarians to predict survival in dogs with gastroenteritis based on simple parameters, low cost and easy implementation / Doutor

Orientador: Dora Maria Grassi-Kassisse / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-09T06:56:08Z (GMT). No. of bitstreams: 1 Crege_DaniloRobertoXavierdeOliveira_M.pdf: 755904 bytes, checksum: b0b863508794d698b250441e9a8d3d1b (MD5) Previous issue date: 2007 / Resumo: O estudo da célula adiposa como entidade funcional do tecido adiposo iniciou-se quando Rodbell em 1964 descreveu a técnica de isolamento de adipócitos de tecido adiposo de ratos e apresentou os efeitos de hormônios no metabolismo de glicose e na lipólise destas células. A partir de então, numerosos são os artigos descrevendo a quantificação de diferentes receptores, bem como, os mensageiros envolvidos com a ativação dos mesmos em célula adiposa. A maioria dos estudos é baseada nesta primeira descrição de Rodbell, entretanto, estes apresentam algumas modificações. Para ensaios provenientes de adipócitos de humanos, a citação também se refere a Rodbell com modificações. O estudo do funcionamento da célula adiposa nas diferentes espécies é emergente, devido à presença na população ocidental da obesidade como pandemia. Além disto, o ensaio de adipócitos isolados de tecido adiposo humano é uma importante ferramenta para estudos farmacológicos de novos fármacos...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: The study of adipose cell as a functional unit of the adipose tissue, began when Rodbell in 1964 described the adipocytes isolation procedure of rat adipose tissue, and showed the effects of hormones in the metabolism of glucose and in lipolysis of these cells. Since that, a great number of researches describing the number of adrenoceptors as well the molecular mechanisms involved with the activation of these receptors has been published. Almost all studies use this first description of Rodbell, however with some modifications. The isolation procedure to human adipocytes also refer the Rodbell's original procedure with modifications. The functional study of adipose tissue in different species is emerging due the presence of obesity as a pandemic problem in occidental population. Beside this, the isolation of adipocytes from the adipose tissue is an important tool to new pharmacological studies of novel drugs...Note: The complete abstract is available with the full electronic digital thesis or dissertations / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular

Orientador: Orival Andries Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Fisica / Made available in DSpace on 2018-08-10T17:19:17Z (GMT). No. of bitstreams: 1 Moraes_RafaelCarvalhode_M.pdf: 1070177 bytes, checksum: 8337e1b190e477073ddd2c7bd737c36c (MD5) Previous issue date: 2008 / Resumo: No esporte de rendimento a elaboração de testes coerentes para controle do treinamento é fundamental. O objetivo deste trabalho foi propor e validar testes de Limiar Anaeróbio (LAn) para o nado crawl. Para isso 14 nadadores competitivos em nível estadual (7 Homens e 7 Mulheres) foram selecionados para o estudo. Cada atleta realizou 5 testes de LAn com dois dias de recuperação entre testes, sendo 4 deles consolidados na literatura: testes de 30, 12, 10 minutos (T30¿, T12¿e T10¿respectivamente), um teste de Lactato Mínimo (LACmin) adaptado de Tegtbur et al. (1993), e um teste elaborado e proposto que consistia em oito minutos nadando (T8¿) a uma velocidade máxima e constante. Foram coletadas amostras de sangue para medida da concentração de lactato sanguíneo ([LAC]), freqüência cardíaca (FC), velocidade (Vel) e variação de ritmo durante os percursos. As amostras de sangue foram coletadas antes e em momentos pós testes para verificação da cinética do lactato sanguíneo. A partir dos dados obtidos verificou-se para todos os testes de tempo que não houve variação de ritmo durante o percurso nadado. Para ambos os grupos a velocidade do T30¿ (1,27 m/s ± 0,046 para o Grupo Homens (GH) e 1,10 m/s ± 0,07 para o Grupo Mulheres (GM)) não apresentou diferenças significativas em relação à velocidade do LACmin (1,29 m/s ± 0,035 para GH e 1,14 m/s ± 0,048 para GM) . Para o GH os testes T8¿ (1,37 m/s ± 0,030), T10¿ (1.35 m/s ± 0,043) e T12¿ (1,34 m/s ± 0,031) não mostraram diferenças entre suas velocidades, mas superestimaram as velocidades do T30¿ e LACmin. O mesmo ocorreu para o GM, para os testes T8¿ (1,18 m/s ± 0,050) e T12¿ (1,16 m/s ± 0,059), com exceção para o T10¿ (1,16 m/s ± 0,050) que não apresentou diferenças em relação ao T30¿ e LACmin. Em relação à [LAC] (mmol/L), não houve diferenças significativas entre T8¿ (12.62 ± 1.02) e T12¿ (12.51 ± 2.37) e entre T30¿ (8.02 ± 1.95) e LACmín (7.84 ± 1.80) para o GH sendo que o T10¿ foi o teste que alcançou maior [LAC] (15.66 ± 2.18). Já para o GM houve diferenças entre T8¿ (11.68 ± 1.47) e T30¿ (6.43 ± 2.29), T10¿ (11.82 ± 1.96) e T30¿ e T12¿ (12.06 ± 2.50) e T30¿, mas não houve diferenças entre T30¿ e LACmín (8.43 ± 3.22). A FC não teve correlação com nenhum dos testes realizados tanto em relação à [LAC] sanguíneo quanto em relação à velocidade. Com isso, adotar valores fixos de FC e [LAC] pode sub ou superestimar o desempenho aeróbio de atletas. Desta forma testes incrementais ou mais longos como o T30¿ parecem ser mais adequados para determinação do LAn individual / Abstract: It is essential to set up coherent measurement tests for training control in high performance sports. This study aims to propose and evaluate tests of Anaerobic Threshold (AT) for crawl swimming style. This study involves 14 competitive swimmers at state level: a group of 7 men (Men) and another group of 7 women (Women). Each athlete has performed 5 tests of AT, with two days of recovery among the tests, 4 of which are proposed and consolidated in the literature: tests of 30, 12, 10 minutes (T30¿, T12¿and T10¿, respectively) and one test of Minimum Lactate adapted from Tegtbur et al. (1993). The last test, proposed by the researcher, consists of 8- minute (T8') swimming at maximal and constant speed. All tests measured athletes¿ blood lactate concentration ([LAC]), heart rating (HR), speed (Vel), and test rhythm variation. The blood samples for the verification of blood lactate concentration were collected before and after the test, in order to verify the kinetic of the blood lactate referring to each test. Based on the analysis of the speed and rhythm, it was possible to verify that, in all the time tests, there was no variation of rhythm during the distance athletes swam. Moreover, the speed in T30¿ (1,27 m/s ± 0,046 in the group of men (GH) e 1,10 m/s ± 0,07 for women¿s group (GM)) does not register significant difference for either group when compared to the speed in the Minimum Lactate test (1,29 m/s ± 0,035 for GH e 1,14 m/s ± 0,048 for GM). In the group of men, the T8¿ (1,37 m/s ± 0,030), T10¿ (1.35 m/s ± 0,043) and T12¿ (1,34 m/s ± 0,031) tests do not show differences regarding speed, but overestimate the speed in T30¿ and Minimum Lactate tests. The same is valid for the women¿s group for T8¿ (1,18 m/s ± 0,050) and T12¿ (1,16 m/s ± 0,059), in which the only difference is that the T10¿ showed equivalent readings when compared to the T30¿ and the Minimum Lactate test. About [LAC] the GH do not show differences between T8¿ (12.62 ± 1.02) and T12¿ (12.51 ± 2.37) neither T30¿ (8.02 ± 1.95) and LACmín (7.84 ± 1.80) and the T10¿was the test of higher [LAC] (15.66 ± 2.18). For GM [LAC] show differences between T8¿ (11.68 ± 1.47) and T30¿ (6.43 ± 2.29), T10¿ (11.82 ± 1.96) and T30¿ and T12¿(12.06 ± 2.50) and T30¿, but there was no difference among T30¿ and LACmín (8.43 ± 3.22). The HR did not relate to any tests and can be compared to neither the blood lactate concentration [LAC], with very individualized readings, nor to each test speed. Therefore, the HR should not be seen as a herald of athlete¿s performance. It is possible to conclude that fixing values for HR and blood lactate concentration [LAC] may distort a swimmer¿s performance capacity by either underestimating or overestimating it. So, incremental tests or longer tests, such as T30¿, seem to be more reliable for determining AT on an individual basis / Mestrado / Ciencia do Desporto / Mestre em Educação Física

The effects of an increase in body temperature per se on the lactate and pyruvate concentrations of the arterial blood, muscle venous blood, sagittal sinus blood, and cerebrospinal fluid were determined. Paralysed anesthetized dogs with near normal arterial pH and PC0(2) values were ventilated with a 50% 0(2), 50% N(2) mixture and heated to a temperature of 42°C and maintained at this temperature for a period of 2 hours. During hyperthermia a slight increase in lactate and pyruvate was observed in the arterial blood. However, this was not statistically significant. Also a slight increase in the concentration of these substances occurred in the muscle venous blood and sagittal sinus blood. This change, however, was parallel to that observed in the arterial blood. The lactate-pyruvate ratio of the arterial blood, muscle venous blood and sagittal sinus blood did not show any significant change and thus no increase in anaerobic processes was detected during the hyperthermic period. On the other hand the cerebrospinal fluid lactate and pyruvate increased significantly throughout the hyperthermic period but maintained a constant lactate-pyruvate ratio. The results indicate that the increase of lactate and pyruvate in the cerebrospinal fluid are a result of an increased rate of aerobic glycolysis. The fact that the increases observed in the cerebrospinal fluid lactate and pyruvate were not reflected in the cerebral venous blood indicates lactate and pyruvate may have difficulty in diffusing across the blood brain barrier and cerebral venous blood is thus a poor index of cerebral lactate and pyruvate changes. / Medicine, Faculty of / Cellular and Physiological Sciences, Department of / Graduate

In order to test the effect of artificially induced alkalosis and acidosis on the appearance of blood lactate and work production, six well-trained oarsmen (age= 23.8 ±2.5 wt = 82.0 ±7.5kg.) were tested on three separate occasions after ingestion of 0.3 gm/kg body wt. NH4C1 (acidosis) , NaHC03 (alkalosis) or a placebo (control). Blood was taken from a forearm vein immediately prior to exercise for determination of pH and bicarbonate (HC03). One hour following the ingestion period, subjects rowed on a stationary ergometer at a pre-determined sub-maximal rate for 4 minutes, then underwent an immediate transition to a maximal effort for 2 minutes. Blood samples from an indwelling catheter placed in the cephalic vein were taken at rest and every 30 seconds throughout the 6 minute exercise test, and every 3 minutes during a 30 minute passive recovery period. Pre-exercise blood values demonstrated significant differences (p<0.01) in pH and HC03 in all three conditions. Work outputs were unchanged in the submaximal test and in the maximal test (p>0.05), although a trend toward decreased production was evident in the acidotic condition. Analysis of exercise blood samples using ANOVA with repeated measures revealed that the linear increase in blood lactate concentration([BLA]) during control was significantly greater than acidosis (p<0.01), although [BLa] during alkalosis were consistently elevated above control there was no significant difference in the linear trend (p>0.05). During recovery, there was no significant difference in the rate of lactate disappearance amongst the three conditions. It was concluded that under this protocol artificial manipulation of the acid-base status of the blood does not significantly influence work production despite significantly reduced [BLa] during acidosis. The inability of these pH changes to alter exercise performance emphasizes the relative importance of the intracellular and the extracellular buffer systems in well trained athletes. / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate

During sustained exercise, working muscles must be supplied with adequate kinds and amounts of exogenous fuels, and the delivery rates of oxygen and oxidizable substrates should be matched. The study of metabolite fluxes and their regulation is therefore critical to the understanding of exercise metabolism. Lactate has received renewed attention from physiologists and biochemists with the realization that it is not only an end product of glycolysis, but also an important fuel for aerobic work. As an oxidizable fuel, this substrate may provide some performance advantage over other fuels such as glucose and free fatty acids. The goals of this thesis were: 1) to determine whether endurance-adapted animals can support higher plasma lactate turnover rates than sedentary animals; and 2) to investigate the major factors involved in the regulation of plasma metabolite turnover at the whole-organism level - using lactate as a model. Lactate turnover rates were measured by bolus injection of [U-¹⁴C]lactate in skipjack tuna, Katsuwonus pelamis, and in thoroughbred racehorses, Equus caballus. In tuna, turnover rates ranged from 112 to 431 umol min⁻¹ kg⁻¹ and they were positively correlated with lactate concentration (slope = 15.1, r = 0.92). This teleost is able to support higher plasma lactate turnover rates than expected for a mammalian lower temperature, and lactate is probably an important oxidizable fuel in this species. For comparative purposes, resting turnover rates of lactate and glucose were plotted versus body mass on a log-log scale for a wide range of mammalian species. These plots were linear, and they showed the same slope as the classic body mass vs metabolic rate relationship. Thoroughbred horses are likely to have an aerobic scope of 40-fold or more. One of their main physiological adaptations to exercise is the ability to increase hematocrit by more than one and a half-fold in response to exercise. In the present study, this adjustment allowed them to reach an A-V difference in 0₂ content of more than 23 vol% during maximal exercise, a much higher value than other mammals. Their lactate turnover rate and cardiac output were measured at rest and two levels of submaximal exercise (45 and 55 V0₂ max) to investigate the relationship between cardiovascular adjustments on plasma lactate turnover rate. Cardiac output ranged from 106 to 571 ml min⁻¹ kg⁻¹, and mean lactate turnover rate from 9.3 at rest, to 75.9 umol min⁻¹ kg⁻¹ at 55% V0₂ max. In contrast with the situation found in tuna, the lactate turnover rates of thoroughbreds were not elevated compared with other mammals, showing that the metabolic adaptations of these outstanding athletes do not include the ability to sustain higher lactate fluxes than sedentary animals. In horses, the contribution of plasma lactate oxidation to V0₂ is minimal, and this substrate is not an important oxidative fuel; lipid oxidation may represent their major pathway for aerobic energy production during exercise. The ability to oxidize plasma lactate at high rates is therefore not necessarily required for the "elite" performance of endurance exercise. This study also shows that both, plasma lactate concentration and cardiac output are positively correlated with turnover rate. The correlation between cardiac output and lactate turnover rate is independent of the relationship between plasma lactate concentration and turnover rate. Plasma metabolite concentration and cardiac output can be regulators of plasma metabolite turnover rate. It is proposed that these two variables are, respectively, the fine and coarse controls for flux rate adjustments during exercise. / Science, Faculty of / Zoology, Department of / Graduate

O exercício físico aumenta a concentração do GH sérico. Durante o mesmo ocorre elevação da lactacidemia, o que pode estimular a secreção hormonal. Pretendemos investigar se o lactato poderia ser um fator que ative o eixo somatotrófico. Usaram-se ratos Wistar adultos, (a) submetidos à injeção ip de 15 e 150 <font face=\"symbol\">mmols de lactato, na fase clara ou escura, sendo sacrificados após 30\', 60\' e 120\' da injeção (Agudo) ou (b) submetidos à infusão ev de 15 e 150 <font face=\"symbol\">mmols de lactato, na fase clara ou escura (Crônico). Coletou-se suas hipófise e fígado para avaliação da expressão do GH (mRNA e proteína) e do mRNA de IGF-I. Análise em 2 way ANOVA. O lactato injetado não alterou a lactacidemia e glicemia dos grupos. Também não houve alteração nos parâmetros analisados no grupo agudo claro. As duas doses de lactato aumentaram o mRNA do GH e IGF-I e o conteúdo sérico de GH do grupo agudo escuro. O lactato apenas aumentou o mRNA de GH e seu conteúdo sérico do grupo crônico escuro. Em suma, o lactato produzido no exercício físico pode ser um dos fatores que ativam o eixo somatotrófico. / Exercise increases serum GH concentrations. During the same occurs elevation of lactate, which can stimulate hormone secretion. We intend to investigate whether lactate could be a factor that activates the somatotrophic axis. We used adult male Wistar rats (a) subjected to ip injection of 15 and 150 <font face=\"symbol\">mmols lactate during light or dark phase, and sacrificed after 30\', 60\' and 120\' injection (acute) or (b) subject to ev infusion of 15 and 150 <font face=\"symbol\">mmols lactate, in light or dark phase (chronic). Pituitary and their liver were collected to evaluate the GH expression (mRNA and protein) and IGF-I mRNA. The analysis was made by 2-way ANOVA. The injected lactate did not change serum lactate and glucose groups. No change in the parameters analyzed in the acute light group. The two lactate doses increased GH and IGF-I mRNA and GH serum content of the group acute dark. The lactate only increased GH mRNA and serum content of chronic dark group. In short, the lactate produced in the exercise may be one of the factors that activate the somatotropic axis.

Severe sepsis and septic shock comprise a significant number of emergency department (ED) admissions annually. With the advent of early goal directed therapies, early identification and intervention have become paramount in this population. Few studies, however, have examined the role of serum lactate as a predictor of mortality or endpoint to resuscitation among this population. We aimed to show that improved lactate clearance is associated with decreased 28-day in-hospital mortality. We retrospectively examined data from the Yale Sepsis Registry for patients with severe sepsis or septic shock who had lactate levels that were measured initially in the ED and subsequently when the patient arrived on the floor. This study received institutional review board approval. Lactate clearance was calculated as a percentage, and comparison between patients who cleared lactate and those who did not were made for mortality data as well as baseline characteristics and interventions required between the two groups. 207 patients (110 male) with mean age and standard deviation (SD) of 63.17 ± 17.9 years were examined. 136 patients (65.7%) were diagnosed with severe sepsis and 71 patients (34.3%) had septic shock. Of those with identified sources of infection, pneumonia was the most common (54 patients, 26.1%). There were 171 patients in the clearance group and 36 patients in the non-clearance group, all of whom had a mean time of 9 hours 8 minutes ± 4 hours 6 minutes between lactate measurements. 28-day mortality rates were 15.2% (26 patients) in the lactate clearance group and 36.1% (13 patients) in the non-clearance group (p<0.01). Vasopressor support within 72 hours of admission was initiated among 61.1% (22 patients) in the non-clearance group compared with 36.8% (63 patients) in the clearance group (p<0.01). Mechanical ventilation was required for 36.3% (62 patients) in the clearance group and 66.7% (24 patients) in the non-clearance group (p=0.001). Rates of severe sepsis, mean number of SIRS and organ dysfunction criteria, and initial creatinine were similar between the two groups; however, only 86.1% (31 patients) in the non-clearance group received intravenous fluids in the ED compared with 98.8% (169 patients) in the clearance group (p=0.002). 33.3% (12 patients) in the non-clearance group had chronic obstructive pulmonary disease (COPD) compared with 15.2% (26 patients) in the clearance group (p<0.05). The mean Mortality in Emergency Department Sepsis (MEDS) scores were 8.78 ± 3.96 for the clearance group and 10.4 ± 4.48 for the non-clearance group (95% CI, -3.1 to -.14, p<0.05). These results show significantly higher mortality rates among patients who do not clear their lactate in the ED. Additionally, these patients require vasopressor support and mechanical ventilation more often. Lactate clearance was significantly associated with receipt of fluids and may also reflect lower MEDS score. Our findings suggest lactate clearance could be used as an endpoint for ED resuscitation and in stratifying mortality risk among patients with severe sepsis or septic shock. Future studies might seek to prospectively validate these findings and incorporate multivariate analysis to determine factors affecting lactate clearance.