Efecto de la infusión de lactato de sodio 0.5 molar sobre el medio interno de pacientes críticos / Effect of half-molar sodium lactate infusion on biochemical parameters in critically ill patients

Objetivo Evaluar el impacto de la infusión de lactato de sodio 0,5M sobre variables del medio interno y sobre la presión intracraneana en pacientes críticos. Diseño Estudio prospectivo experimental de cohorte única. Ámbito Unidad de cuidados intensivos de un hospital universitario. Pacientes Pacientes con shock y neurocríticos con hipertensión intracraneana. Intervenciones Se infundió una carga de 500 cc de infusión de lactato de sodio 0,5M en 15 min y se midió el nivel plasmático de sodio, potasio, magnesio, calcio, cloro, lactato, bicarbonato, PaCO2 arterial, pH, fosfato y albúmina en 3 tiempos: T0 preinfusión; T1 a los 30 min y T2 a los 60 min postinfusión. Se midieron la presión arterial media y presión intracraneana en T0 y T2. Resultados Recibieron el fluido N=41: n=19 como osmoagente y 22 como expansor. Se constató alcalosis metabólica: T0 vs. T1 (p=0,007); T1 vs. T2 (p=0,003). La natremia aumentó en los 3 tiempos (T0 vs. T1; p<0,0001; T1 vs. T2; p=0,0001). Se demostró un descenso de la presión intracraneana (T0: 24,83±5,4 vs. T2: 15,06±5,8; p <0,001). El lactato aumentó inicialmente (T1) con un rápido descenso (T2) (p <0,0001), incluso en aquellos pacientes con hiperlactatemia basal (p=0,002). Conclusiones La infusión de lactato de sodio 0,5M genera alcalosis metabólica, hipernatremia, disminución de la cloremia y un cambio bifásico del lactato, y muestra eficacia en el descenso de la presión intracraneana en pacientes con daño encefálico agudo. (AU)

Objective To evaluate the impact of the infusion of sodium lactate 500ml upon different biochemical variables and intracranial pressure in patients admitted to the intensive care unit. Design A prospective experimental single cohort study was carried out. Scope Polyvalent intensive care unit of a university hospital. Patients Critical patients with shock and intracranial hypertension. Procedure A 500ml sodium lactate bolus was infused in 15min. Plasma levels of sodium, potassium, magnesium, calcium, chloride, lactate, bicarbonate, PaCO2, pH, phosphate and albumin were recorded at 3timepoints: T0 pre-infusion; T1 at 30minutes, and T2 at 60minutes post-infusion. Mean arterial pressure and intracranial pressure were measured at T0 and T2. Results Forty-one patients received sodium lactate: 19 as an osmotically active agent and 22 as a volume expander. Metabolic alkalosis was observed: T0 vs. T1 (P=0.007); T1 vs. T2 (P=0.003). Sodium increased at the 3time points (T0 vs. T1, P<0.0001; T1 vs. T2, P=0.0001). In addition, sodium lactate decreased intracranial pressure (T0: 24.83±5.4 vs. T2: 15.06±5.8; P<0.001). Likewise, plasma lactate showed a biphasic effect, with a rapid decrease at T2 (P<0.0001), including in those with previous hyperlactatemia (P=0.002). Conclusions The infusion of sodium lactate is associated to metabolic alkalosis, hypernatremia, reduced chloremia, and a biphasic change in plasma lactate levels. Moreover, a decrease in intracranial pressure was observed in patients with acute brain injury. (AU)

Effect of half-molar sodium lactate infusion on biochemical parameters in critically ill patients.

OBJECTIVE: To evaluate the impact of the infusion of sodium lactate 500ml upon different biochemical variables and intracranial pressure in patients admitted to the intensive care unit. DESIGN: A prospective experimental single cohort study was carried out. SCOPE: Polyvalent intensive care unit of a university hospital. PATIENTS: Critical patients with shock and intracranial hypertension. PROCEDURE: A 500ml sodium lactate bolus was infused in 15min. Plasma levels of sodium, potassium, magnesium, calcium, chloride, lactate, bicarbonate, PaCO2, pH, phosphate and albumin were recorded at 3 timepoints: T0 pre-infusion; T1 at 30min, and T2 at 60min post-infusion. Mean arterial pressure and intracranial pressure were measured at T0 and T2. RESULTS: Forty-one patients received sodium lactate: 19 as an osmotically active agent and 22 as a volume expander. Metabolic alkalosis was observed: T0 vs. T1 (p=0.007); T1 vs. T2 (p=0.003). Sodium increased at the 3 timepoints (T0 vs. T1, p<0.0001; T1 vs. T2, p=0.0001). In addition, sodium lactate decreased intracranial pressure (T0: 24.83±5.4 vs. T2: 15.06±5.8; p<0.001). Likewise, plasma lactate showed a biphasic effect, with a rapid decrease at T2 (p<0.0001), including in those with previous hyperlactatemia (p=0.002). CONCLUSIONS: The infusion of sodium lactate is associated to metabolic alkalosis, hypernatremia, reduced chloremia, and a biphasic change in plasma lactate levels. Moreover, a decrease in intracranial pressure was observed in patients with acute brain injury.

Acute responses of high-intensity circuit training in women: Low physical fitness levels show higher muscle damage / Respostas agudas de um circuito de treino de alta intensidade em mulheres: Níveis baixos de aptidão física apresentam maior dano muscular

High-intensity intermittent exercise (HIIE) elicits large improvements in health and cardiorespiratory fitness (CRF). HIIE can be applied with calisthenics exercises to improve strength and endurance. The acute effects of high-intensity circuit training (HICT) considering different CRF on myological variables are unknown. The aim was measure acute effects of HICT in young women considering different levels of CRF. Twelve women were allocated in two groups, who achieve 41mLO2•kg-1•min-1 or more= High Physical Fitness (HPF, n=5) and who achieve less than 41mLO2•kg-1•min-1= Low Physical Fitness (LPF,n=7). Protocol: 2x4 sets of 20 seconds at maximum intensity (all-out fashion) interspersed with 10 seconds of passive rest (jumping jacks, squat and thrust using 2kg dumbbells, mountain climber, and burpees). Blood samples were collected before, immediately after, 15minutes, 30minutes, one hour and 24 hours after. Heart rate, serum myoglobin, lactate, and creatine kinase (CK) concentration were analyzed. The HR achieved 94.1±3.7% of HRmax for LPF and 104.5±20.3% for HPF, p=0.03. The mean of delta lactate was similar between groups. The highest myoglobin has reached at 1h after the exercise protocol, with 50.0±30.2 ng/mL for LPF and 36.9±9.25 ng/mL for HPF. The delta of total CK before and after the exercise protocol shows that the serum CK level in LPF was significantly higher than HPF group (p=0.042). HICT composed by calisthenic protocol produced elevated and similar effects on HRmax, serum lactate and myoglobin in the woman with HPF and LPF. However, LPF group presented higher muscle damage inferred by serum CK concentrations.

O exercício intermitente de alta intensidade(HIIE) melhora a saúde e a aptidão cardiorrespiratória(CRF). HIIE pode ser aplicado com exercícios calistênicos para melhorar a força e resistência. Os efeitos agudos do treinamento de alta intensidade(HICT) considerando diferentes CRF em variáveis miológicas são desconhecidos. O objetivo foi medir os efeitos agudos do HICT em mulheres jovens, considerando diferentes níveis de CRF. Elas foram alocadas pelo nível de VO2máx. em dois grupos, as que atingiram 41mLO2•kg-1•min-1 ou mais= alta aptidão física(HPF,n=5) e menos de 41mLO2•kg-1•min-1= baixo aptidão física(LPF,n=7). Protocolo: 2x4 séries de 20s com intensidade máxima (all-out) intercalados com 10s de repouso passivo (jumping jacks, squat and thrust usando halteres 2kg, mountain climber e burpees). Sangue foi coletado antes, zero, 15, 30min, 1h e 24hs depois. Foram analisadas, freqüência cardíaca, mioglobina sérica, lactato e creatina quinase (CK). A FC alcançou 94,1±3,7% da FCmax para LPF e 104,5±20,3% para HPF, p=0,03. A média do delta lactato foi semelhante entre os grupos. O pico de mioglobina foi 1h após o protocolo de exercício, com 50.0±30.2ng/mL para LPF e 36.9±9.25ng/mL para HPF. O delta de CK total antes e depois do protocolo de exercício mostra que o nível sérico de CK no LPF foi significativamente maior do que o grupo HPF(p=0,042). O HICT com exercícios calistênicos produziu efeitos elevados e semelhantes sobre FCmax, lactato sérico e mioglobina nas mulheres com alta e baixa aptidão física. No entanto, o grupo LPF apresentou maior dano muscular inferido pelas concentrações séricas de CK.

A velocidade de infusão da solução poli-iônica intravenosa contendo 84mEq/L de lactato determina a intensidade do efeito alcalinizante em equinos / The intravenous polyionic solution with 84mEq/L of lactate infusion rate determines the intensity of the alkalizing effect in horses

O objetivo deste trabalho foi verificar os efeitos da solução poli-iônica intravenosa contendo 84mEq/L de lactato (L84) sobre os equilíbrios hidroeletrolítico e ácido-base de equinos, quando administrada de forma rápida ou lenta. Cinco equinos sadios adultos receberam a infusão contínua intravenosa da L84, em volume correspondente a 10% do peso corporal, em duas ocasiões: a) infusão rápida (16,66mL/kg/h) durante seis horas; b) infusão lenta (8,33mL/kg/h) durante 12 horas. Amostras de sangue venoso foram colhidas ao início da infusão (hora zero) e três, seis, nove, 12 e 24 horas após, e amostras de urina nas horas zero, seis, 12 e 24. Determinaram-se pH (sanguíneo e urinário), pCO2, HCO3 -, BE, PPT, lactato L, Na+, K+, Cl-, AG, SID, Atot, VVP, densidade urinária e excreções fracionadas urinárias de lactato L, Na+, K+ e Cl-. A L84 provoca efeito alcalinizante iatrogênico de menor magnitude quando administrada de forma lenta, porque os mecanismos renais, atuantes durante o período de infusão, promovem a correção gradativa do desequilíbrio. Pode-se concluir que a infusão de forma lenta da solução L84 em equinos é recomendável nos casos em que se suspeite de acidose metabólica e não seja possível quantificar o grau do desequilíbrio.(AU)

The aim of this study was to investigate the effects of an intravenous polyionic solution containing 84mEq/L of lactate (L84) on the hydroelectrolyte and acid-base balances when administered quickly or slowly in horses. Five healthy adult horses received the L84 solution, in a volume corresponding to 10% of BW, by continuous intravenous infusion, in two instants: a) rapid infusion (16.66mL/kg/h) during 6 hours; b) slow infusion (8.33mL/kg/h) during 12 hours. Venous blood samples were taken at the beginning of the infusion (hour 0) and 3, 6, 9, 12, and 24 hours after. Urine samples were taken at 0, 6, 12, and 24h. pH (blood and urine), pCO2, HCO3-, BE, TPP, L-lactate, Na+, K+, Cl-, AG, SID, Atot, PVV, urine specific gravity, and L-lactate, Na+, K+, and Cl- renal fractional clearance were determined. The L84 solution causes lower magnitude alkalizing effect when administered slowly, due to the gradual correction of the iatrogenic imbalance by the kidneys during the infusion period. The L84 solution infused at a low rate in horses could be recommended in cases where metabolic acidosis is suspected and it is not possible to quantify the imbalance degree.(AU)

[Half-molar sodium-lactate: The osmotic agent we are looking for?]. / Lactato de sodio 0,5 molar: ¿el agente osmótico que buscamos?

Intracranial hypertension (ICH) is the most important modifiable factor with predictive negative value in brain injury patients. Osmotherapy is the most important first level specific measure in the treatment of ICH. Mannitol 20%, and 3, 7.5, 10, and 23% hypertonic sodium chloride are the most commonly used osmotic agents in the neurocritical care setting. Currently, controversy about the best osmotic agent remains elusive. Therefore, over the past few years, half-molar sodium lactate has been introduced as a new osmotic agent to be administered in the critically ill. Lactate is able to prevent hyperchloremia, as well as its adverse effects such as hyperchloremic acidosis, systemic inflammation, and acute kidney injury. Furthermore, lactate may also be used by glia as energy substrate in brain injury patients. Half-molar sodium lactate would also have a more potent and long-lasting effect decreasing intracellular osmolarity and by inhibiting neuronal volume control mechanisms. Pioneering researches in patients with traumatic brain injury have shown a more significant effect than mannitol on the control of ICH. In addition, in this group of patients this solution appears to be beneficial in preventing episodes of ICH. However, future research is necessary to corroborate or not these promising results.

Efficacy of florfenicol and intravenous fluid therapy for treatment of experimental salmonellosis in newborn calves / Eficácia do florfenicol e da fluidoterapia parenteral no tratamento da salmonelose experimental em bezerros neonatos

The efficacy of florfenicol associated or not to intravenous fluid therapy for treatment of Salmonella Dublin-infected calves was determined. Twenty-four healthy 10 to 15-day-old Holstein calves were randomly allotted into four groups, with six animals each: control (group 1); infected with 10(8)CFU Salmonella Dublin and not treated (group 2); infected with 10(8)CFU Salmonella Dublin and treated with florfenicol (group 3); and infected with 10(8)CFU Salmonella Dublin and treated with florfenicol associated to fluid therapy (group 4). All animals were submitted to physical examination just before inoculation and every 24 hours, during seven days after experimental infection. Rectal swabs and blood samples were collected for Salmonella Dublin isolation and pH and blood electrolytes determination. The experimental infection with Salmonella Dublin induced clinical signs of salmonellosis, such as diarrhea and fever, and caused reduction in blood concentrations of pH, sodium, potassium and chlorides. The treated calves showed good clinical recovery, and the group treated with antibiotic in combination to fluid therapy presented a faster and more efficient correction of the hydro-electrolyte balance.

Avaliou-se a eficácia terapêutica do florfenicol associado ou não à fluidoterapia intravenosa no tratamento de bezerros infectados experimentalmente com Salmonella Dublin. Foram utilizados 24 bezerros sadios da raça Holandesa com 10 a 15 dias de idade, distribuídos aleatoriamente em quatro grupos experimentais, constituídos por seis animais cada: controle (grupo 1); infectado com 10(8)UFC de Salmonella Dublin e não tratado (grupo 2); infectado com 10(8)UFC de Salmonella Dublin e tratado com florfenicol (grupo 3); e infectado com 10(8)UFC de Salmonella Dublin (grupo 4) e tratado com florfenicol associado à fluidoterapia. Todos os animais foram submetidos ao exame físico logo antes da inoculação e a cada 24 horas, durante sete dias após a infecção experimental. Foram colhidas amostras de suabes retais para o isolamento de Salmonella Dublin e amostras de sangue para determinação dos valores de pH e dosagem de eletrólitos sanguíneos. A infecção experimental com Salmonella Dublin induziu sinais clínicos de salmonelose, como diarreia e febre, e provocou redução do valor do pH e das concentrações sanguíneas de sódio, potássio e cloreto. Os bezerros submetidos aos tratamentos mostraram boa recuperação clínica, sendo que o grupo tratado com antibiótico combinado à fluidoterapia apresentou correção mais rápida e eficiente do equilíbrio hidroeletrolítico.