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1.
Sci Rep ; 11(1): 14274, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-34253775

RESUMO

This paper uses Monte Carlo simulations to investigate the interaction of short-wave infrared (SWIR) light with vascular tissue as a step toward the development of a non-invasive optical sensor for measuring blood lactate in humans. The primary focus of this work was to determine the optimal source-detector separation, penetration depth of light at SWIR wavelengths in tissue, and the optimal light power required for reliable detection of lactate. The investigation also focused on determining the non-linear variations in absorbance of lactate at a few select SWIR wavelengths. SWIR photons only penetrated 1.3 mm and did not travel beyond the hypodermal fat layer. The maximum output power was only 2.51% of the input power, demonstrating the need for a highly sensitive detection system. Simulations optimized a source-detector separation of 1 mm at 1684 nm for accurate measurement of lactate in blood.


Assuntos
Ácido Láctico/sangue , Engenharia de Proteínas/métodos , Tecido Adiposo/metabolismo , Adulto , Simulação por Computador , Feminino , Humanos , Raios Infravermelhos , Aprendizado de Máquina , Masculino , Método de Monte Carlo , Dinâmica não Linear , Distribuição Normal , Óptica e Fotônica , Espectroscopia de Luz Próxima ao Infravermelho , Adulto Jovem
2.
Eur J Appl Physiol ; 121(11): 3083-3093, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34319445

RESUMO

PURPOSE: Continuous incremental protocols (CP) may misestimate the maximum aerobic velocity (Vmax) due to increases in running speed faster than cardiorespiratory/metabolic adjustments. A higher aerobic capacity may mitigate this issue due to faster pulmonary oxygen uptake ([Formula: see text]O2) kinetics. Therefore, this study aimed to compare three different protocols to assess Vmax in athletes with higher or lower training status. METHODS: Sixteen well-trained runners were classified according to higher (HI) or lower (LO) [Formula: see text]O2max [Formula: see text]O2-kinetics was calculated across four 5-min running bouts at 10 km·h-1. Two CPs [1 km·h-1 per min (CP1) and 1 km·h-1 every 2-min (CP2)] were performed to determine Vmax [Formula: see text]O2max, lactate-threshold and submaximal [Formula: see text]O2/velocity relationship. Results were compared to the discontinuous incremental protocol (DP). RESULTS: Vmax, [Formula: see text]O2max, [Formula: see text]CO2 and VE were higher [(P < 0.05,(ES:0.22/2.59)] in HI than in LO. [Formula: see text]O2-kinetics was faster [P < 0.05,(ES:-2.74/ - 1.76)] in HI than in LO. [Formula: see text]O2/velocity slope was lower in HI than in LO [(P < 0.05,(ES:-1.63/ - 0.18)]. Vmax and [Formula: see text]O2/velocity slope were CP1 > CP2 = DP for HI and CP1 > CP2 > DP for LO. A lower [P < 0.05,(ES:0.53/0.75)] Vmax-difference for both CP1 and CP2 vs DP was found in HI than in LO. Vmax-differences in CP1 vs DP showed a large inverse correlation with Vmax, [Formula: see text]O2max and lactate-threshold and a very large correlation with [Formula: see text]O2-kinetics. CONCLUSIONS: Higher aerobic training status witnessed by faster [Formula: see text]O2 kinetics led to lower between-protocol Vmax differences, particularly between CP2 vs DP. Faster kinetics may minimize the mismatch issues between metabolic and mechanical power that may occur in CP. This should be considered for exercise prescription at different percentages of Vmax.


Assuntos
Tolerância ao Exercício/fisiologia , Ácido Láctico/sangue , Consumo de Oxigênio/fisiologia , Corrida/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Adulto Jovem
3.
BMC Pharmacol Toxicol ; 22(1): 34, 2021 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-34120651

RESUMO

BACKGROUND: Patients with type 2 diabetes mellitus (T2DM) are characterized by an elevated glycemic index and are at a higher risk for complications such as cardiovascular disease, nephropathy, retinopathy and peripheral neuropathy. Normalization of glycemic index can be achieved by dosing combinations of metformin with other anti-diabetic drugs. The present study (Clintrials number NCT00519480) was conducted to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of remogliflozinetabonate, an SGLT2 inhibitor, withdoses (500 mg and 750 mg BID) greater than the commercial dose (100 mg BID)in combination with metformin with minimum daily dose of 2000 mg given in two divided doses. METHODS: This was a randomized, double-blinded, repeat dose study in 50 subjects with T2DM. The study was conducted in three phases; run-in, randomization, and treatment. All subjects were on a stable metformin dosing regimen. Cohort 1 subjects were randomly allocated to receive either remogliflozin etabonate 500 mg BID or placebo BID (2:1) in addition to metformin. Cohort 2 subjects were administered with either remogliflozin etabonate 750 mg BID or placebo BID (2:1) in addition to metformin for 13 days. All the subjects were assessed for safety (adverse events, lactic acid levels, vital signs, electrocardiogram [ECG]), pharmacokinetic evaluation, and pharmacodynamics (Oral Glucose Tolerance Testing) parameters. RESULTS: Co-administration of remogliflozin etabonate and metformin was well tolerated in all subjects during the observation period. There were no severe or serious adverse events (SAEs) and no increase in lactic acid concentration was reported during the study. The statistical results showed that concomitant administration of remogliflozin etabonate, either 500 mg or 750 mg BID, with metformin had no effect on the pharmacokinetics of metformin. The accumulation ratios, Day 13 vs. Day 1, for AUC values of remogliflozin etabonate and its metabolites were all very close to 1, indicating no accumulation in plasma concentrations of remogliflozin etabonate and its metabolites. Mean glucose values from baseline and glucose and insulin values following oral glucose tolerance test (OGTT) were decreased in all treatment groups. CONCLUSION: Co-administration of doses of remogliflozin etabonate (500 mg BID or 750 mg BID) greater than the commercial dose (100 mg BID) with metformin (2000 mg BID) was shown to be safe and effective during the observation period. TRIAL REGISTRATION: ClinicalTrials.gov , NCT00519480 . Registered:22 August 2007.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Glucosídeos/administração & dosagem , Hipoglicemiantes/administração & dosagem , Metformina/administração & dosagem , Pirazóis/administração & dosagem , Adulto , Glicemia/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/metabolismo , Método Duplo-Cego , Interações Medicamentosas , Quimioterapia Combinada , Jejum/sangue , Jejum/metabolismo , Feminino , Glucosídeos/efeitos adversos , Glucosídeos/farmacocinética , Humanos , Hipoglicemiantes/efeitos adversos , Insulina/sangue , Ácido Láctico/sangue , Masculino , Metformina/efeitos adversos , Metformina/farmacocinética , Pessoa de Meia-Idade , Pirazóis/efeitos adversos , Pirazóis/farmacocinética
4.
Ann Intern Med ; 174(7): 927-935, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33872042

RESUMO

BACKGROUND: Medicare requires that hospitals report on their adherence to the Severe Sepsis and Septic Shock Early Management Bundle (SEP-1). OBJECTIVE: To evaluate the effect of SEP-1 on treatment patterns and patient outcomes. DESIGN: Longitudinal study of hospitals using repeated cross-sectional cohorts of patients. SETTING: 11 hospitals within an integrated health system. PATIENTS: 54 225 encounters between January 2013 and December 2017 for adults with sepsis who were hospitalized through the emergency department. INTERVENTION: Onset of the SEP-1 reporting requirement in October 2015. MEASUREMENTS: Changes in SEP-1-targeted processes, including antibiotic administration, lactate measurement, and fluid administration at 3 hours from sepsis onset; repeated lactate and vasopressor administration for hypotension within 6 hours of sepsis onset; and sepsis outcomes, including risk-adjusted intensive care unit (ICU) admission, in-hospital mortality, and home discharge among survivors. RESULTS: Two years after its implementation, SEP-1 was associated with variable changes in process measures, with the greatest effect being an increase in lactate measurement within 3 hours of sepsis onset (absolute increase, 23.7 percentage points [95% CI, 20.7 to 26.7 percentage points]; P < 0.001). There were small increases in antibiotic administration (absolute increase, 4.7 percentage points [CI, 1.9 to 7.6 percentage points]; P = 0.001) and fluid administration of 30 mL/kg of body weight within 3 hours of sepsis onset (absolute increase, 3.4 percentage points [CI, 1.5 to 5.2 percentage points]; P < 0.001). There was no change in vasopressor administration. There was a small increase in ICU admissions (absolute increase, 2.0 percentage points [CI, 0 to 4.0 percentage points]; P = 0.055) and no changes in mortality (absolute change, 0.1 percentage points [CI, -0.9 to 1.1 percentage points]; P = 0.87) or discharge to home. LIMITATION: Data are from a single health system. CONCLUSION: Implementation of the SEP-1 mandatory reporting program was associated with variable changes in process measures, without improvements in clinical outcomes. Revising the measure may optimize its future effect. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality.


Assuntos
Medicare/organização & administração , Avaliação de Resultados em Cuidados de Saúde , Pacotes de Assistência ao Paciente/normas , Sepse/terapia , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Estudos Transversais , Feminino , Hidratação , Fidelidade a Diretrizes , Humanos , Ácido Láctico/sangue , Estudos Longitudinais , Masculino , Notificação de Abuso , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Melhoria de Qualidade , Sepse/sangue , Estados Unidos , Vasoconstritores/uso terapêutico
5.
Physiol Rep ; 9(4): e14760, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33611843

RESUMO

We investigated whether horses trained in moderate and mild hypoxia demonstrate greater improvement in performance and aerobic capacity compared to horses trained in normoxia and whether the acquired training effects are maintained after 2 weeks of post-hypoxic training in normoxia. Seven untrained Thoroughbred horses completed 4 weeks (3 sessions/week) of three training protocols, consisting of 2-min cantering at 95% maximal oxygen consumption V˙O2max under two hypoxic conditions (H16, FI O2  = 16%; H18, FI O2  = 18%) and in normoxia (N21, FI O2  = 21%), followed by 2 weeks of post-hypoxic training in normoxia, using a randomized crossover study design with a 3-month washout period. Incremental treadmill tests (IET) were conducted at week 0, 4, and 6. The effects of time and groups were analyzed using mixed models. Run time at IET increased in H16 and H18 compared to N21, while speed at V˙O2max was increased significantly only in H16. V˙O2max in all groups and cardiac output at exhaustion in H16 and H18 increased after 4 weeks of training, but were not significantly different between the three groups. In all groups, run time, V˙O2max , VV˙O2max , Q˙max , and lactate threshold did not decrease after 2 weeks of post-hypoxic training in normoxia. These results suggest that 4 weeks of training in moderate (H16), but not mild (H18) hypoxia elicits greater improvements in performance and running economy than normoxic training and that these effects are maintained for 2 weeks of post-hypoxic training in normoxia.


Assuntos
Aptidão Cardiorrespiratória , Cavalos/fisiologia , Hipóxia , Condicionamento Físico Animal , Resistência Física , Corrida , Animais , Biomarcadores/sangue , Estudos Cross-Over , Teste de Esforço/veterinária , Tolerância ao Exercício , Feminino , Frequência Cardíaca , Cavalos/sangue , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio , Fatores de Tempo
6.
Scand J Trauma Resusc Emerg Med ; 29(1): 23, 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33509242

RESUMO

BACKGROUND: One factor leading to the high mortality rate seen in sepsis is the subtle, dynamic nature of the disease, which can lead to delayed detection and under-resuscitation. This study investigated whether serial hemodynamic parameters obtained from a non-invasive cardiac output monitor (NICOM) predicts disease severity in patients at risk for sepsis. METHODS: Prospective clinical trial of the NICOM device in a convenience sample of adult ED patients at risk for sepsis who did not have obvious organ dysfunction at the time of triage. Hemodynamic data were collected immediately following triage and 2 hours after initial measurement and compared in two outcome groupings: (1) admitted vs. dehydrated, febrile, hypovolemicdischarged patients; (2) infectious vs. non-infectious sources. Receiver operator characteristic (ROC) curves were calculated to determine whether the NICOM values predict hospital admission better than a serum lactate. RESULTS: 50 patients were enrolled, 32 (64 %) were admitted to the hospital. Mean age was 49.5 (± 16.5) years and 62 % were female. There were no significant associations between changes in hemodynamic variables and patient disposition from the ED or diagnosis of infection. Lactate was significantly higher in admitted patients and those with infection (p = 0.01, p = 0.01 respectively). The area under the ROC [95 % Confidence Intervals] for lactate was 0.83 [0.64-0.92] compared to 0.59 [0.41-0.73] for cardiac output (CO), 0.68 [0.49-0.80] for cardiac index (CI), and 0.63 [0.36-0.80] for heart rate (HR) for predicting hospital admission. CONCLUSIONS: CO and CI, obtained at two separate time points, do not help with early disease severity differentiation of patients at risk for severe sepsis. Although mean HR was higher in those patients who were admitted, a serum lactate still served as a better predictor of patient admission from the ED.


Assuntos
Débito Cardíaco , Monitorização Fisiológica , Medição de Risco , Sepse/diagnóstico , Adulto , Idoso , Serviço Hospitalar de Emergência , Feminino , Frequência Cardíaca , Humanos , Ácido Láctico/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos de Amostragem , Triagem
7.
Eur J Sport Sci ; 21(1): 84-92, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32090683

RESUMO

The present study investigated the relationships between changes in running economy (RE) and indirect muscle damage markers following downhill running (DHR) to test the hypothesis that decreased RE after DHR would be associated with decreases in muscle function. Forty-five young men ran downhill (-15%) for 30 min at the velocity corresponding to 70% of their peak oxygen uptake (VO2peak). Oxygen uptake (VO2) and other parameters possibly associated with RE (blood lactate concentration, perceived exertion, stride length and frequency) were measured during 5-minute level running at the velocity corresponding to 80%VO2peak before, immediately after and 1-3 days after DHR. Knee extensor maximal voluntary contraction torque (MVC), rate of torque development, vertical jump performance, muscle soreness and serum creatine kinase activity were assessed at the same time points. The values of the dependent variables were compared among time points by one-way ANOVAs followed by Bonferroni post-hoc tests when appropriate. Pearson's correlation tests were used to examine relationships between changes in VO2 (RE parameter) and changes in muscle damage parameters. VO2 during the level run increased (p < 0.05) immediately after DHR (18.3 ± 4.6%) and sustained until 2 days post-DHR (11.7 ± 4.2%). MVC decreased (p < 0.05) immediately (-21.8 ± 6.1%) to 3 days (-13.6 ± 5.9%) post-DHR, and muscle soreness developed 1-3 days post-DHR. The magnitude of changes in VO2 did not significantly (p < 0.05) correlate with the changes in muscle damage makers (r = -0.02-0.13) nor stride length (r = -0.05) and frequency (r = -0.05). The absence of correlation between the changes in VO2 and MVC suggests that strength loss was not a key factor affecting RE.


Assuntos
Músculo Esquelético/fisiologia , Consumo de Oxigênio/fisiologia , Esforço Físico/fisiologia , Corrida/fisiologia , Análise de Variância , Creatina Quinase/sangue , Marcha/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Contração Muscular/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/lesões , Mialgia/fisiopatologia , Corrida/lesões , Fatores de Tempo , Adulto Jovem
8.
J Sports Sci ; 39(3): 312-321, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32924824

RESUMO

The purpose of this investigation was, firstly, to quantify the test-retest reliability of strength measures in adolescent distance runners; and secondly, to explore the relationships between inter-limb strength asymmetry and performance and running economy (RE) in a similar cohort of young runners. For the reliability study, twelve (n = 6 female) post-pubertal adolescent distance runners performed an isometric quarter-squat on a dual force plate and unilateral isometric hip extension and hip abduction tests on two occasions. For the correlation study, participants (n = 31) performed the strength tests plus a submaximal incremental running assessment and a maximal running test. Running economy was expressed as the average energy cost of running for all speeds below lactate turnpoint and was scaled for body mass using a previously calculated power exponent. Allometrically scaled peak force during the quarter-squat and peak torque in the hip strength tasks showed acceptable levels of reproducibility (typical error ≤6.3%). Relationships between strength asymmetry and performance and RE were low or negligible (r < 0.47, p > 0.05), except for hip abduction strength asymmetry and RE in the female participants (r = 0.85, p < 0.001, n = 16). Practitioners should consider inter-limb hip abduction strength asymmetry on an individual level, and attempting to reduce this asymmetry in females may positively impact RE.


Assuntos
Lateralidade Funcional , Extremidade Inferior/fisiologia , Força Muscular , Resistência Física/fisiologia , Corrida/fisiologia , Adolescente , Índice de Massa Corporal , Comportamento Competitivo/fisiologia , Metabolismo Energético , Teste de Esforço , Feminino , Quadril/fisiologia , Humanos , Contração Isométrica , Ácido Láctico/sangue , Masculino , Reprodutibilidade dos Testes
9.
Int J Sports Med ; 42(8): 740-748, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33307555

RESUMO

This study aimed to evaluate the effect of high-intensity interval training shock microcycles (HIITSM) on endurance, running economy and change of direction economy in female soccer players. Nineteen sub-elite female soccer players were randomised to two groups: HIITSM (10 HIIT sessions over 13 days) or HIITTRAD (4 HIIT sessions over 13 days) interventions. Endurance performance was evaluated through the 30-15 intermittent fitness test (30-15IFT); running economy over a 5-min treadmill run; and change of direction economy over two conditions: (1) 5-min 20m shuttle run, and (2) 5-min 10m shuttle run. HIITSM significantly improved 30-15IFT scores compared to baseline (+4.4%, p=0.009; d=0.96) and 30-15IFT scores relative to HIITTRAD (p=0.002; d=2.01). There was no significant interaction (group×time) for running economy and change of direction economy. Pre- to post- intervention there was a significant main time effect for blood lactate over 20m and 10m shuttle runs (p<0.001 and p=0.037, respectively), with large (d=0.93) and moderate (d=0.53) changes observed for the HIITSM over the two distances, respectively. HIITSM may be more effective than HIITTRAD to improve 30-15IFT over shorter training periods but may not affect running economy and change of direction economy.


Assuntos
Treinamento Intervalado de Alta Intensidade/métodos , Movimento/fisiologia , Resistência Física/fisiologia , Corrida/fisiologia , Futebol/fisiologia , Estatura , Peso Corporal , Teste de Esforço/métodos , Feminino , Frequência Cardíaca , Humanos , Ácido Láctico/sangue , Estudos Longitudinais , Consumo de Oxigênio , Fatores Sexuais , Fatores de Tempo , Adulto Jovem
10.
Int J Rehabil Res ; 44(1): 24-31, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33136618

RESUMO

Aerobic fitness assessment in patients with low back pain (LBP) may help clinicians to plan how to progress the aerobic training. This was a pilot study designed to evaluate the performance of people with LBP on two different aerobic fitness tests performed on a treadmill and to compare the measure of aerobic fitness between people with LBP and healthy individuals. Ten people with LBP and 10 healthy individuals underwent two aerobic fitness protocols, the modified Bruce and maximum incremental test protocols, performed on a treadmill. Data collected during the protocols were: oxygen consumption, heart rate (HR), blood lactate concentration, respiratory quotient, rating of perceived exertion response, and pain intensity. Independent t-test and two-way analysis of variance were used respectively to assess difference between groups characteristics and physiological responses to the protocols. Our results showed that both groups were similar with regards to age (P = 0.839) or HRrest (P = 0.730) but the LBP group showed higher BMI compared to the healthy group (P = 0.031). Regarding the performance of both groups on the aerobic fitness tests, the only significant difference was reported for respiratory quotient which showed a main effect of test (P = 0.015) with higher values favoring the modified Bruce over the incremental test. Our study showed that most people with LBP are able to perform and tolerate both aerobic fitness tests but no significant differences between people with LBP and healthy individuals on both protocols were reported.


Assuntos
Dor Crônica/fisiopatologia , Teste de Esforço , Dor Lombar/fisiopatologia , Aptidão Física/fisiologia , Adulto , Índice de Massa Corporal , Feminino , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio/fisiologia , Medição da Dor , Esforço Físico/fisiologia , Projetos Piloto , Taxa Respiratória/fisiologia
11.
Int J Sports Physiol Perform ; 16(2): 280-286, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33120361

RESUMO

PURPOSE: To evaluate the reliability of new change-of-direction-economy tests (assessing energetic efficiency when performing continuous shuttle runs) compared with common running-economy tests in soccer players Methods: Sixteen subelite, male soccer players were recruited to perform a testing battery involving running economy (RE), 10-m shuttle-running economy (SRE10), and 20-m shuttle-running economy (SRE20) at 8.4 km·h-1 mean speed on 2 different days within 48 hours. SRE10 and SRE20 consisted of continuous shuttle runs interspersed with 180° directional changes. During the RE, SRE20, and SRE10 tests, respiratory exchange ratio and oxygen uptake were collected and used to calculate the movement-economy values over any running condition as oxygen cost and energetic cost. The secondary variables (carbon dioxide production, heart rate, minute ventilation, and blood lactate) were also monitored during all tests. RESULTS: Depending on expression (oxygen cost or energetic cost), reliability was established for RE (CV: 5.5%-5.8%; ICC = .77-.88), SRE10 (CV: 3.5%-3.8%; ICC = .78-.96), and SRE20 (CV: 3.5%-3.8%; ICC = .66-.94). All secondary physiological variables reported good reliability (CV < 10%), except for blood lactate (CV < 35.8). The RE, SRE10, and SRE20 tests show good reliability in soccer players, whereas blood lactate has the highest variability among physiological variables during the economy tests. CONCLUSION: The assessment of change-of-direction economy through performing 20- and 10-m shuttle runs is reliable and can be applied to evaluate soccer players' energetic movement efficiency under more soccer-specific running conditions.


Assuntos
Movimento , Corrida/fisiologia , Futebol/fisiologia , Teste de Esforço , Frequência Cardíaca , Humanos , Ácido Láctico/sangue , Masculino , Reprodutibilidade dos Testes
12.
Biomed Res Int ; 2020: 2608318, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33150168

RESUMO

Blood lactate concentration predicts mortality in critically ill patients and is clinically used in the diagnosis, grading of severity, and monitoring response to therapy of septic shock. This paper summarizes available quantitative data to provide the first comprehensive description and critique of the accepted concepts of the physiology of lactate in health and shock, with particular emphasis on the controversy of whether lactate release is simply a manifestation of tissue hypoxia versus a purposeful transfer ("shuttle") of lactate between tissues. Basic issues discussed include (1) effect of nonproductive lactate-pyruvate exchange that artifactually enhances flux measurements obtained with labeled lactate, (2) heterogeneous tissue oxygen partial pressure (Krogh model) and potential for unrecognized hypoxia that exists in all tissues, and (3) pathophysiology that distinguishes septic from other forms of shock. Our analysis suggests that due to exchange artifacts, the turnover rate of lactate and the lactate clearance are only about 60% of the values of 1.05 mmol/min/70 kg and 1.5 L/min/70 kg, respectively, determined from the standard tracer kinetics. Lactate turnover reflects lactate release primarily from muscle, gut, adipose, and erythrocytes and uptake by the liver and kidney, primarily for the purpose of energy production (TCA cycle) while the remainder is used for gluconeogenesis (Cori cycle). The well-studied physiology of exercise-induced hyperlactatemia demonstrates massive release from the contracting muscle accompanied by an increased lactate clearance that may occur in recovering nonexercising muscle as well as the liver. The very limited data on lactate kinetics in shock patients suggests that hyperlactatemia reflects both decreased clearance and increased production, possibly primarily in the gut. Our analysis of available data in health and shock suggests that the conventional concept of tissue hypoxia can account for most blood lactate findings and there is no need to implicate a purposeful production of lactate for export to other organs.


Assuntos
Hipóxia/diagnóstico , Ácido Láctico/sangue , Ácido Pirúvico/sangue , Choque Cardiogênico/diagnóstico , Choque Hemorrágico/diagnóstico , Choque Séptico/diagnóstico , Animais , Estado Terminal , Modelos Animais de Doenças , Cães , Humanos , Hipóxia/sangue , Fígado/metabolismo , Modelos Biológicos , Músculos/metabolismo , Ovinos , Choque Cardiogênico/sangue , Choque Hemorrágico/sangue , Choque Séptico/sangue , Suínos
13.
JAMA Netw Open ; 3(9): e2013580, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32926114

RESUMO

Importance: The longer-term risk of rehospitalizations and death of adult sepsis survivors is associated with index sepsis illness characteristics. Objective: To derive and validate a parsimonious prognostic score for unplanned rehospitalizations or death in the first year after hospital discharge of adult sepsis survivors. Design, Setting, and Participants: This cohort study used data from the Intensive Care National Audit & Research Centre Case Mix Programme database on adult sepsis survivors identified from consecutive critical care admissions to 192 adult general critical care units in England, United Kingdom, between April 1, 2009, and March 31, 2014 (94 748 patients in the derivation cohort), and between April 1, 2014, and March 31, 2015 (24 669 patients in the validation cohort). Statistical analysis was performed from July 5 to October 31, 2019. Generic characteristics (age, sex, race/ethnicity, 2015 Index of Multiple Deprivation [IMD2015] in England quintiles, preadmission dependence, previous hospitalizations in the year preceding index sepsis admission, comorbidity, admission type, Acute Physiology and Chronic Health Evaluation II physiology score, hospital length of stay, worst blood lactate and blood hemoglobin concentrations, and type of hospital) and sepsis-specific characteristics (site of infection, numbers of organ dysfunctions, and organ support) at the index sepsis admission were used as predictors. Main Outcomes and Measures: Prognostic score derived and validated using multivariable logistic regression for the outcome of unplanned rehospitalization or death in the first year after hospital discharge of adult sepsis survivors, as well as clinical usefulness assessed using decision curve analysis. Prognostic score validation was performed for internal validation with bootstrapping and temporal cohort external validation. Results: This cohort study included 94 748 patients (51 164 men [54.0%]; mean [SD] age, 61.3 [17.0] years) in the derivation cohort and 24 669 patients (13 255 men [53.7%]; mean [SD] age, 62.1 [16.8%]) in the validation cohort. Unplanned rehospitalization or death in the first year after hospital discharge occurred for 48 594 patients (51.3%) in the derivation cohort and 13 129 patients (53.2%) in the validation cohort. Eight independent predictors were identified and weighted to generate a prognostic score for every patient: previous hospitalizations, age in 10-year increments, IMD2015 in England quintiles, preadmission dependence, comorbidities, admission type, blood hemoglobin level, and site of infection. The total prognostic score ranged from 0 to 22 points, with lower scores indicating a lower risk of the outcome. The derivation and validation cohorts had similar rates of prognostic scores of 0 to 4 points (5088 of 16 684 patients [30.5%] and 471 of 1725 patients [27.3%]) and prognostic scores of 11 points or more (15 732 of 21 641 patients [72.7%] and 5753 of 7952 patients [72.3%]). The area under the receiver operating characteristic curve for the prognostic score was 0.675 (95% CI, 0.672-0.679). The decision curve analysis highlighted an optimal score cutoff of 7 points or more. Conclusions and Relevance: The prognostic score reported in this study uses 8 internationally feasible predictors measured during the index sepsis admission and provides clinically useful information on sepsis survivors' risk of unplanned rehospitalization or death in the first year after hospital discharge.


Assuntos
Hospitalização/estatística & dados numéricos , Efeitos Adversos de Longa Duração/mortalidade , Readmissão do Paciente/estatística & dados numéricos , Medição de Risco/métodos , Sepse , Adulto , Causalidade , Cuidados Críticos/métodos , Cuidados Críticos/estatística & dados numéricos , Inglaterra/epidemiologia , Feminino , Hemoglobinas/análise , Mortalidade Hospitalar , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Ácido Láctico/sangue , Tempo de Internação/estatística & dados numéricos , Masculino , Múltiplas Afecções Crônicas , Prognóstico , Sepse/sangue , Sepse/epidemiologia , Sepse/terapia
14.
Arq. bras. med. vet. zootec. (Online) ; 72(5): 1631-1638, Sept.-Oct. 2020. tab
Artigo em Português | LILACS, VETINDEX | ID: biblio-1131547

RESUMO

Avaliações com o intuito de mensurar marcadores de eficiência na performance esportiva do cavalo Crioulo são escassas e de fundamental importância no que tange às possíveis especificidades da raça. O objetivo do presente trabalho foi avaliar e determinar os padrões de frequência cardíaca, velocidade, concentração de lactato e gasto energético de equinos da raça Crioula durante provas credenciadoras ao Freio de Ouro. Tais variáveis foram avaliadas durante a realização das etapas funcionais da competição. Observaram-se flutuações superiores da variável frequência cardíaca (FC) durante a realização das etapas de Andadura, Figura, Volta sobre Patas e Esbarradas (And/fig/VSP) (203bpm) e menores valores na etapa Paleteada II (185bpm) (P<0,05). Em relação à velocidade, o maior valor atingido foi registrado na etapa de Paleteada II (39,7km/h). A concentração de lactato sanguíneo aferida se mostrou elevada em todas as fases da competição, sendo o maior valor observado na etapa de Paleteada II (14,5mmol/L) (P<0,05) e o menor durante a etapa de Mangueira I (9,3mmol/L). Superior gasto energético foi atribuído à etapa de And/Fig/VSP (853,28kcal/kgPV/min). Portanto, todas as etapas funcionais podem ser classificadas como anaeróbias, por apresentarem concentrações de lactato sanguíneo acima de 4mmol/L, e demandam alto gasto energético pelos competidores.(AU)


Evaluations of athletic performance markers of Crioulo breed horses are scarce yet fundamentally important regarding possible unique characteristics of this breed. This study aimed to evaluate and determine heart rate, speed, blood lactate and energy expenditure patterns of Crioulo breed horses during qualifying tests in the functional phases of the "Freio de Ouro" championship. Higher values of heart rate during the phases "andadura, figura, voltas sobre patas, esbarradas" (And/Fig/VSP) (203bpm) and lower values at "Paleteada II" (185bpm) (P<0.05) were noticed. Regarding speed variable, the maximum value was registered at "Paleteada II" (39.7km/h). During all the phases, blood lactate concentration was high, with the highest value found at "Paleteada II" (14.5mm/L) and the lowest during "Mangueira I" (9.3mm/L) (P<0.05). Superior energy expenditure was noticed in the "And/Fig/VSP" phase (853.28Kcal/kgPV/min). Thus, all functional phases can be classified as anaerobic, as blood lactate concentrations remained above 4mmol/L, with high energy demand of the horses.(AU)


Assuntos
Animais , Condicionamento Físico Animal/fisiologia , Ácido Láctico/sangue , Metabolismo Energético , Frequência Cardíaca/fisiologia , Cavalos/fisiologia
15.
BMC Nephrol ; 21(1): 358, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32854655

RESUMO

BACKGROUND: Acute kidney injury (AKI) is independently related to the adverse outcome of septic shock, but it lacks effective early predictors. Renal anginal index (RAI) was used to predict subsequent severe AKI (AKIs) in critically ill patients. The application of RAI in children with septic shock has not been reported. This study aims to evaluate the efficacy of early RAI in predicting subsequent AKIs within 3 days after PICU admission in children with septic shock by comparing with early fluid overload (FO) and early creatinine elevation. METHODS: Sixty-six children admitted to PICU aged 1 month to 16 years old, with septic shock from January 2016 to December 2019 were analyzed retrospectively. According to the 2012 Kidney Disease Improving Global outcomes (KDIGO) criteria, AKIs was defined by the KDIGO stage ≥2 within 3 days after PICU admission. Early RAI positive (RAI+) was defined as RAI ≥ 8 within 12 h of PICU admission. Any elevation of serum creatinine (SCr) over baseline within 12 h after PICU admission was denoted as "Early SCr > base". Early FO positive (FO+) was defined as FO > 10% within 24 h of PICU admission. RESULTS: Of 66 eligible cases, the ratio of early RAI+, early SCr > base, early FO+ was 57.57, 59.09 and 16.67% respectively. The incidence of AKIs in early RAI+ group (78.94%) was higher than that in early RAI- group (21.42%) (p = 0.04), and there was no significant difference compared with the early FO+ group (71.79%) and early SCr > base group (81.82%) (P > 0.05). After adjustment for confounders, early RAI+ was independently associated with the occurrence of AKIs within 3 days (OR 10.04, 95%CI 2.39-42.21, p < 0.01). The value of early RAI+ (AUC = 0.78) to identify patients at high risk of AKIs was superior to that of early SCr > base (AUC = 0.70) and early FO+ (AUC = 0.58). A combination of serum lactate with early RAI+ improved the predictive performance for assessing AKIs (AUC = 0.83). CONCLUSIONS: Early RAI could be used as a more convenient and effective index to predict the risk of AKIs in children with septic shock within 3 days. Early RAI+ combined with serum lactate improved the predictive performance for assessing AKIs.


Assuntos
Injúria Renal Aguda/epidemiologia , Creatinina/sangue , Choque Séptico/terapia , Desequilíbrio Hidroeletrolítico/epidemiologia , Injúria Renal Aguda/sangue , Injúria Renal Aguda/terapia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Unidades de Terapia Intensiva Pediátrica/estatística & dados numéricos , Ácido Láctico/sangue , Tempo de Internação , Modelos Logísticos , Masculino , Transplante de Órgãos/estatística & dados numéricos , Terapia de Substituição Renal , Respiração Artificial/estatística & dados numéricos , Medição de Risco , Índice de Gravidade de Doença , Choque Séptico/sangue , Choque Séptico/epidemiologia , Transplante de Células-Tronco/estatística & dados numéricos , Vasoconstritores/uso terapêutico
16.
Eur J Appl Physiol ; 120(9): 2005-2018, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32591994

RESUMO

PURPOSE: Breath-by-breath energy expenditure during open water swimming has not yet been explored in an ecological environment. This study aimed to investigate and compare energetics and kinematics of 5 km swimming, in both swimming pool and open water conditions. METHODS: Through four independent studies, oxygen uptake ([Formula: see text]2) kinetics, heart rate (HR), blood lactate concentration ([La-]) and glucose level (BGL), metabolic power ([Formula: see text]), energy cost (C) and kinematics were assessed during 5 km front crawl trials in a swimming pool and open water conditions. A total of 38 competitive open water swimmers aged 16-27 years volunteered for this four part investigation: Study A (pool, ten females, 11 males), Study B (pool, four females, six males), Study C (pool case study, one female) and Study D (open water, three females, four males). RESULTS: In the swimming pool, swimmers started with an above average swimming speed (v), losing efficiency along the 5 km, despite apparent homeostasis for [La-], BGL, [Formula: see text]2, [Formula: see text] and C. In open water, swimmers started the 5 km with a below average v, increasing the stroke rate (SR) in the last 1000 m. In open water, [Formula: see text]2 kinetics parameters, HR, [La-], BGL, respiratory exchange ratio and C were affected by the v and SR fluctuations along the 5 km. CONCLUSIONS: Small fluctuations were observed for energetic variables in both conditions, but changes in C were lower in swimming pool than in open water. Coaches should adjust the training plan accordingly to the specificity of open water swimming.


Assuntos
Metabolismo Energético/fisiologia , Natação/fisiologia , Adolescente , Adulto , Desempenho Atlético/fisiologia , Feminino , Glucose/metabolismo , Frequência Cardíaca/fisiologia , Humanos , Cinética , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio/fisiologia , Respiração , Água , Adulto Jovem
18.
Emerg Med J ; 37(6): 363-369, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32317296

RESUMO

BACKGROUND: Routine use of the Sequential Organ Failure Assessment (SOFA) score to prognosticate patients with sepsis is challenged by the requirement to perform numerous laboratory tests. The prognostic accuracy of the quick SOFA (qSOFA) without or with lactate criteria has not been prospectively investigated in low and middle income countries. We assessed the performance of simplified prognosis criteria using qSOFA-lactate criteria in the emergency department of a hospital with limited resources, in comparison with SOFA prognosis criteria and systemic inflammatory response syndrome (SIRS) screening criteria. METHODS: This prospective cohort study was conducted between March and December 2017 in adult patients with suspected bacterial infection visiting the emergency department of the Indonesian National Referral Hospital. Variables from sepsis prognosis and screening criteria and venous lactate concentration at enrolment were recorded. Patients were followed up until hospital discharge or death. Prognostic accuracy was measured using area under the receiver operating characteristic curve (AUROC) of each criterion in the prediction of in-hospital mortality. RESULTS: Of 3026 patients screened, 1213 met the inclusion criteria. The AUROC of qSOFA-lactate criteria was 0.74 (95% CI 0.71 to 0.77). The AUROC of qSOFA-lactate was not statistically significantly different to the SOFA score (AUROC 0.75, 95% CI 0.72 to 0.78; p=0.462). The qSOFA-lactate was significantly higher than qSOFA (AUROC 0.70, 95% CI0.67 to 0.74; p=0.006) and SIRS criteria (0.57, 95% CI0.54 to 0.60; p<0.001). CONCLUSIONS: The prognostic accuracy of the qSOFA-lactate criteria is as good as the SOFA score in the emergency department of a hospital with limited resources. The performance of the qSOFA criteria is significantly lower than the qSOFA-lactate criteria and SOFA score.This abstract has been translated and adapted from the original English-language content. Translated content is provided on an "as is" basis. Translation accuracy or reliability is not guaranteed or implied. BMJ is not responsible for any errors and omissions arising from translation to the fullest extent permitted by law, BMJ shall not incur any liability, including without limitation, liability for damages, arising from the translated text.


Assuntos
Infecções Bacterianas/classificação , Infecções Bacterianas/mortalidade , Ácido Láctico/análise , Escores de Disfunção Orgânica , Adulto , Área Sob a Curva , Infecções Bacterianas/diagnóstico , Serviço Hospitalar de Emergência/organização & administração , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Humanos , Indonésia/epidemiologia , Ácido Láctico/sangue , Masculino , Pessoa de Meia-Idade , Mortalidade , Prognóstico , Curva ROC , Índice de Gravidade de Doença
19.
J Trauma Acute Care Surg ; 88(5): 671-676, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32317577

RESUMO

BACKGROUND: Acute mesenteric ischemia (AMI) is a highly morbid disease with a diverse etiology. The American Association for the Surgery of Trauma (AAST) proposed disease-specific grading scales intended to quantify severity based upon clinical, imaging, operative, and pathology findings. This grading scale has not been yet been validated for AMI. The goal of this study was to evaluate the correlation between the grading scale and complication severity. METHODS: Patients for this single center retrospective chart review were identified using diagnosis codes for AMI (ICD10-K55.0, ICD9-557.0). Inpatients >17 years old from the years 2008 to 2015 were included. The AAST grades (1-5) were assigned after review of clinical, imaging (computed tomography), operative and pathology findings. Two raters applied the scales independently after dialog with consensus on a learning set of cases. Mortality and Clavien-Dindo complication severity were recorded. RESULTS: A total of 221 patients were analyzed. Overall grade was only weakly correlated with Clavien-Dindo complication severity (rho = 0.27) and mortality (rho = 0.21). Computed tomography, pathology, and clinical grades did not correlate with mortality or outcome severity. There was poor interrater agreement between overall grade. A mortality prediction model of operative grade, use of vasopressors, preoperative serum creatinine and lactate levels showed excellent discrimination (c-index = 0.93). CONCLUSION: In contrast to early application of other AAST disease severity scales, the AMI grading scale as published is not well correlated with outcome severity. The AAST operative grade, in conjunction with vasopressor use, creatinine, and lactate were strong predictors of mortality. LEVEL OF EVIDENCE: Prognostic study, III.


Assuntos
Isquemia Mesentérica/diagnóstico , Índice de Gravidade de Doença , Idoso , Creatinina/sangue , Feminino , Custos Hospitalares/estatística & dados numéricos , Mortalidade Hospitalar , Humanos , Ácido Láctico/sangue , Tempo de Internação/economia , Tempo de Internação/estatística & dados numéricos , Masculino , Isquemia Mesentérica/sangue , Isquemia Mesentérica/economia , Isquemia Mesentérica/mortalidade , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Medição de Risco/métodos , Sociedades Médicas , Estados Unidos/epidemiologia
20.
Arch Pediatr ; 27(4): 206-211, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32278589

RESUMO

BACKGROUND: Plasma lactate has been used to predict the prognosis of critically ill children, but mortality risk scores appear to be more appealing, particularly in resource-limited countries. OBJECTIVE: To assess the prognostic utility of lactate compared with the pediatric Sequential Organ Failure Assessment (pSOFA) score among the general pediatric intensive care unit (PICU) population. METHODS: This was a prospective observational study including 78 children admitted to a tertiary-level PICU. Plasma lactate was measured upon admission and repeated 24h later. pSOFA score, Pediatric Risk of Mortality, and Pediatric Index of Mortality-2 (PIM2) were calculated. The primary outcome was 30-day mortality. RESULTS: In total, 47.4% of patients had hyperlactatemia at admission. Among these, 20.5% had persistent hyperlactatemia. No significant difference in admission lactate level was found between survivors and nonsurvivors. The 24-h, peak, and average lactate levels were higher among nonsurvivors (P=0.005, 0.035, and 0.019, respectively). The 24-h lactate level and pSOFA score were independent predictors of mortality (adjusted odds ratio and 95% confidence interval=1.12 [1.02-1.23] and 1.80 [1.23-2.64], respectively]. The 24-h lactate level showed positive correlations with pSOFA, PRISM, and PIM2 (Spearman correlation coefficient=0.31, 0.23, 0.43; P=0.006, P=0.047, P<0.001, respectively). The 24-h lactate level had an area under the receiver operating characteristic curve (AUC) of 0.77 (P=0.013) for mortality prediction, while admission, peak, and average lactate level had an AUC of 0.69, 0.69, 0.71 (P=0.086, P=0.035, P=0.019), respectively. PIM2, PRISM, and pSOFA score had an AUC of 0.80, 0.78, 0.82 (P=0.001, P=0.001, and P<0.001), respectively. Combining 24-h lactate level with pSOFA demonstrated superior performance (AUC=0.88). CONCLUSION: Both 24-h lactate level and pSOAF are useful for prediction of mortality. Incorporating the 24-h lactate level into the pSOFA Score achieved superior prognostic utility.


Assuntos
Regras de Decisão Clínica , Estado Terminal/mortalidade , Ácido Láctico/sangue , Insuficiência de Múltiplos Órgãos/diagnóstico , Insuficiência de Múltiplos Órgãos/mortalidade , Escores de Disfunção Orgânica , Adolescente , Biomarcadores/sangue , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Modelos Logísticos , Masculino , Insuficiência de Múltiplos Órgãos/sangue , Projetos Piloto , Prognóstico , Estudos Prospectivos
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