A Slow-Exchange Interstitial Fluid Compartment in Volunteers and Anesthetized Patients: Kinetic Analysis and Physiology.

BACKGROUND: Physiological studies suggest that the interstitial space contains 2 fluid compartments, but no analysis has been performed to quantify their sizes and turnover rates. METHODS: Retrospective data were retrieved from 270 experiments where Ringer's solution of between 238 and 2750 mL (mean, 1487 mL) had been administered by intravenous infusion to awake and anesthetized humans (mean age 39 years, 47% females). Urinary excretion and hemoglobin-derived plasma dilution served as input variables in a volume kinetic analysis using mixed-models software. RESULTS: The kinetic analysis successfully separated 2 interstitial fluid compartments. One equilibrated rapidly with the plasma and the other equilibrated slowly. General anesthesia doubled the rate constants for fluid entering these 2 compartments (from 0.072 to 0.155 and from 0.026 to 0.080 min -1 , respectively). The return flows to the plasma were impeded by intensive fluid therapy; the rate constant for the fast-exchange compartment decreased from 0.251 to 0.050 when the infusion time increased from 15 to 60 minutes, and the rate constant for the slow-exchange compartment decreased from 0.019 to 0.005 when the infused volume increased from 500 to 1500 mL. The slow-exchange compartment became disproportionately expanded when larger fluid volumes were infused and even attained an unphysiologically large size when general anesthesia was added, suggesting that the flow of fluid was restrained and not solely determined by hydrostatic and oncotic forces. The dependence of the slow-exchange compartment on general anesthesia, crystalloid infusion rate, and infusion volume all suggest a causal physiological process. CONCLUSIONS: Kinetic analysis supported that Ringer's solution distributes in 2 interstitial compartments with different turnover times. The slow compartment became dominant when large amounts of fluid were infused and during general anesthesia. These findings may explain why fluid accumulates in peripheral tissues during surgery and why infused fluid can remain in the body for several days after general anesthesia.

Balanced Crystalloids Versus Normal Saline in Kidney Transplant Patients: An Updated Systematic Review, Meta-analysis, and Trial Sequential Analysis.

BACKGROUND: The use of balanced crystalloids over normal saline for perioperative fluid management during kidney transplantation and its benefits on acid-base and electrolyte balance along with its influence on postoperative clinical outcomes remains a topic of controversy. Therefore, we conducted this review to assess the impact of balanced solutions compared to normal saline on outcomes for kidney transplant patients. METHODS: We searched MEDLINE, EMBASE, and Cochrane databases for randomized controlled trials (RCTs) comparing balanced lower-chloride solutions to normal saline in renal transplant patients. Our main outcome of interest was delayed graft function (DGF). Additionally, we examined acid-base and electrolyte measurements, along with postoperative renal function. We computed relative risk (RR) using the Mantel-Haenszel test for binary outcomes, and mean difference (MD) for continuous data, and applied DerSimonian and Laird random-effects models to address heterogeneity. Furthermore, we performed a trial sequential analysis (TSA) for all outcomes. RESULTS: Twelve RCTs comprising a total of 1668 patients were included; 832 (49.9%) were assigned to receive balanced solutions. Balanced crystalloids reduced the occurrence of DGF compared to normal saline, with RR of 0.82 (95% confidence interval [CI], 0.71-0.94), P = .005; I² = 0%. The occurrence was 25% (194 of 787) in the balanced crystalloids group and 34% (240 of 701) in the normal saline group. Moreover, our TSA supported the primary outcome result and suggests that the sample size was sufficient for our conclusion. End-of-surgery chloride (MD, -8.80 mEq·L -1 ; 95% CI, -13.98 to -3.63 mEq.L -1 ; P < .001), bicarbonate (MD, 2.12 mEq·L -1 ; 95% CI, 1.02-3.21 mEq·L -1 ; P < .001), pH (MD, 0.06; 95% CI, 0.04-0.07; P < .001), and base excess (BE) (MD, 2.41 mEq·L -1 ; 95% CI, 0.88-3.95 mEq·L -1 ; P = .002) significantly favored the balanced crystalloids groups and the end of surgery potassium (MD, -0.17 mEq·L -1 ; 95% CI, -0.36 to 0.02 mEq·L -1 ; P = .07) did not differ between groups. However, creatinine did not differ in the first (MD, -0.06 mg·dL -1 ; 95% CI, -0.38 to 0.26 mg·dL -1 ; P = .71) and seventh (MD, -0.06 mg·dL -1 ; 95% CI, -0.18 to 0.06 mg·dL -1 ; P = .30) postoperative days nor urine output in the first (MD, -1.12 L; 95% CI, -3.67 to 1.43 L; P = .39) and seventh (MD, -0.01 L; 95% CI, -0.45 to 0.42 L; P = .95) postoperative days. CONCLUSIONS: Balanced lower-chloride solutions significantly reduce the occurrence of DGF and provide an improved acid-base and electrolyte control in patients undergoing kidney transplantation.

Fluids and body composition during anesthesia in children and adolescents: A pilot study.

The purpose of this study is to evaluate the intracellular and extracellular volume before and after anesthesia in order to ascertain their variations and determine the potential utility of this information in optimizing intraoperative fluid administration practices. A bioimpedance spectroscopy device (body composition monitor, BCM) was used to measure total body fluid volume, extracellular volume, and intracellular volume. BCM measurements were performed before and after general anesthesia in unselected healthy children and adolescents visiting the Pediatric Institute of Southern Switzerland for low-risk surgical procedures hydrated with an isotonic solution. In 100 children and adolescents aged 7.0 (4.8-11) years (median and interquartile range), the average total body water increased perioperatively with a delta value of 182 (0-383) mL/m2 from pre- to postoperatively, as well as the extracellular water content, which had a similar increase with a delta value of 169 (19-307) mL/m2. The changes in total body water and extracellular water content significantly correlated with the amount of fluids administered. The intracellular water content did not significantly change.   Conclusion: Intraoperative administration of isotonic solutions results in a significant fluid accumulation in low-risk schoolchildren during general anesthesia. The results suggest that children without major health problems undergoing short procedures do not need any perioperative intravenous fluid therapy, because they are allowed to take clear fluids up to 1 h prior anesthesia. In future studies, the use of BCM measurements has the potential to be valuable in guiding intraoperative fluid therapy. What is Known: • Most children who undergo common surgical interventions or investigations requiring anesthesia are nowadays hydrated at a rate of 1700 mL/m2/day with an isotonic solution. • The use bioimpedance spectroscopy for the assessment of fluid status in healthy children has already been successfully validated. • The bioimpedance spectroscopy is already currently widely used in various nephrological settings to calculate fluid overload and determine patient's optimal fluid status. What is New: • Routine intraoperative fluid administration results in a significant fluid accumulation during general anesthesia in low-risk surgical procedures. • This observation might be relevant for children and adolescents with conditions predisposing to fluid retention. • In future studies, the use of BCM measurements has the potential to be valuable in guiding intraoperative fluid therapy.

How to follow the guidelines, when the appropriate fluid is missing?

Intravenous maintenance fluid therapy (IV-MFT) is probably the most prescribed drug in paediatric hospital care. Recently paediatric societies have produced evidence-based practice guidelines that recommend the use of balanced isotonic fluid when prescribing IV-MFT in both acute and critical paediatric care. Unfortunately, the applicability of these guidelines could be called into question when a ready-to-use glucose-containing balanced isotonic fluid is not available. The main objective of this study was to describe the availability of glucose-containing balanced isotonic fluids in European and Middle Eastern paediatric acute and critical care settings. This work is an ancillary study of the survey dedicated to IV-MFT practices in the paediatric acute and critical care settings in Europe and Middle East, a cross-sectional electronic 27-item survey, emailed in April-May 2021 to paediatric critical care physicians across 34 European and Middle East countries. The survey was developed by an expert multi-professional panel within the European Society of Peadiatric and Neonatal Intensive Care (ESPNIC). Balanced isotonic fluid with glucose 5% was available for only 32/153 (21%) responders. Balanced isotonic fluid with glucose 5% was consistently available in the UK (90%) but not available in France, Greece, The Netherlands and Turkey.    Conclusion: Ready-to-use isotonic balanced IV solutions containing glucose in sufficient amount exist but are inconsistently available throughout Europe. National and European Medication Safety Incentives should guarantee the availability of the most appropriate and safest IV-MFT solution for all children. What is Known: • Intravenous maintenance fluid therapy (IV-MFT) is probably the most prescribed drug in paediatric hospital care. • Balanced isotonic fluid is recommended when prescribing IV-MFT in both acute and critical paediatric care. What is New: • Balanced isotonic fluid with glucose 5% is available for less than 25% of the prescribers in Europe and the Middle East. Availability of balanced isotonic fluid with glucose 5% varies from one country to another but can also be inconsistent within the same country. • Clinicians who have access to a ready-to-use balanced isotonic fluid with glucose 5% are more likely to consider its use than clinicians who do not have access to such an IV solution.

Fluid distribution during surgery in the flat recumbent, Trendelenburg, and the reverse Trendelenburg body positions.

BACKGROUND: The distribution and elimination of infused crystalloid fluid is known to be affected by general anesthesia, but it is unclear whether changes differ depending on whether the patient is operated in the flat recumbent position, the Trendelenburg ("legs up") position, or the reverse Trendelenburg ("head up") position. METHODS: Retrospective data on hemodilution and urine output obtained during and after infusion of 1-2 L of Ringer's solution over 30-60 min were collected from 61 patients undergoing surgery under general anesthesia and 106 volunteers matched with respect to the infusion volume and infusion time. Parameters describing fluid distribution in the anesthetized and awake subjects were compared by population volume kinetic analysis. RESULTS: General anesthesia decreased the rate constant for urine output by 79% (flat recumbent), 91% (legs up) and 91% (head up), suggesting that laparoscopic surgery per se intensified the already strong anesthesia-induced fluid retention. General anesthesia also decreased the rate constant governing the return of the distributed fluid to the plasma by 32%, 15%, and 70%, respectively. These results agree with laboratory data showing a depressive effect of anesthetic drugs on lymphatic pumping, and further suggest that the "legs up" position facilitates lymphatic flow, whereas the "head up" position slows this flow. Both Trendelenburg positions increased swelling of the "third fluid space". CONCLUSIONS: General anesthesia caused retention of infused fluid with preferential distribution to the extravascular space. Both Trendelenburg positions had a modifying influence on the kinetic adaptations that agreed with the gravitational forces inflicted by tilting to body.

Comparison of bicarbonate Ringer's solution with lactated Ringer's solution among postoperative outcomes in patients with laparoscopic right hemihepatectomy: a single-centre randomised controlled trial.

The study was aimed to investigate the positive impact of bicarbonate Ringer's solution on postoperative outcomes in patients who underwent laparoscopic right hemihepatectomy. Patients in the two groups were infused with lactated Ringer's solution (LRS, n = 38) and the bicarbonate Ringer's solution (BRS, n = 38) at a rate of 5 ml·kg-1·h-1. The stroke volume was monitored and 200 ml of hydroxyethyl starch with 130/0.4 sodium chloride injection (Hes) of a bolus was given in the first 5-10 min. The main outcome was to test lactic acid (LAC) concentration before and after surgery. The concentrations of LAC in the LRS group were higher than in the BRS group at 2 h after operation began, at the end of the operation and 2 h after the operation. Overall, the parameters including pH, base excess (BE), HCO3-, aspartate transaminase (AST) and alanine transaminase (ALT) were improved. The values of bilirubin in the LRS group were higher and albumin were lower than in the BRS group at post-operation 1st and 2nd day (P<0.05). The time of prothrombin time (PT) and activated partial thromboplastin time (APTT) in the LRS group were longer than that in the BRS group at post-operation 1st and 2nd day (P<0.05). Likewise, the concentrations of Mg2+, Na+ and K+ also varied significantly. The length of hospital was reduced, and the incidence of premature ventricular contractions (P = 0.042) and total complications (P = 0.016) were lower in group BRS. TRIAL REGISTRATION: The study was registered at clinicalTrials.gov with the number ChiCTR2000038077 on 09/09/2020.

The patterns in urine excretion and transvascular fluid exchange in human subjects during intravenous fluid infusion: A quantitative analysis.

INTRODUCTION: Investigations of responses of animals and humans to changes of plasma volume are usually reported as average responses of groups of individuals. This ignores considerable quantitative variation between individuals. We examined the hypothesis that individual responses follow a common temporal pattern with variations reflecting different parameters describing that pattern. METHODS: We illustrate this approach using data of Hahn, Lindahl and Drobin (Acta Anaesthesiol Scand.2011, 55:987-94) who measured urine volume and haemoglobin dilution of 10 female subjects during intravenous Ringer infusions for 30 min and subsequent 3.5 h. The published time courses were digitised and analysed to determine if a family of mathematical functions accounted for the variation in individual responses. RESULTS: Urine excretion was characterised by a time delay (Td) before urine flow increased and a time course of cumulative urine excretion described by a logarithmic function. This logarithmic relation forms the theoretical basis of a family of linear relations describing urine excretion as a function of Td. Measurement of Td enables estimation of subsequent values of urine excretion and thereby the fraction of infused fluid retained in the body. CONCLUSION: The approach might be useful for physiologists and clinical investigators to compare the response to infusion protocols when both test and control responses can be described by linear relations between cumulative urine volume at specific times and Td. The approach may also be useful for clinicians by complementing strategies to guide fluid therapy by enabling the later responses of an individual to be predicted from their earlier response.

Current Thoughts on Burn Resuscitation.

The optimal treatment of burn shock is still unresolved. The problem of "fluid creep" continues despite modern devices that fail to improve outcomes over hourly urine output. Colloids, especially albumin, reduce fluid requirements. Albumin can be used either immediately at the start of resuscitation, or as a "rescue" when crystalloid use is excessive. Several studies confirm that when crystalloid resuscitation is "out of control" the majority of caregivers will add albumin to reduce fluid rates. A multi-center trial is underway comparing crystalloids with albumin to confirm the benefit of colloids. The next question is whether albumin or plasma is as the better colloid choice.

Early Fluid Is Less Fluid: Comparing Early Versus Late ICU Resuscitation in Severely Injured Trauma Patients.

OBJECTIVES: The temporal trends of crystalloid resuscitation in severely injured trauma patients after ICU admission are not well characterized. We hypothesized early crystalloid resuscitation was associated with less volume and better outcomes than delaying crystalloid. DESIGN: Retrospective, observational. SETTING: High-volume level 1 academic trauma center. PATIENTS: Adult trauma patients admitted to the ICU with emergency department serum lactate greater than or equal to 4 mmol/dL, elevated lactate (≥ 2 mmol/L) at ICU admission, and normal lactate by 48 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: For the 333 subjects, we analyzed patient and injury characteristics and the first 48 hours of ICU course. Receipt of greater than or equal to 500 mL/hr of crystalloid in the first 6 hours of ICU admission was used to distinguish early vs. late resuscitation. Outcomes included ICU length of stay (LOS), ventilator days, and acute kidney injury (AKI). Unadjusted and multivariable regression methods were used to compare early resuscitation vs. late resuscitation. Compared with the early resuscitation group, the late resuscitation group received more volume by 48 hours (5.5 vs. 4.1 L; p ≤ 0.001), had longer ICU LOS (9 vs. 5 d; p ≤ 0.001), more ventilator days (5 vs. 2 d; p ≤ 0.001), and higher occurrence rate of AKI (38% vs. 11%; p ≤ 0.001). On multivariable regression, late resuscitation remained associated with longer ICU LOS and ventilator days and higher odds of AKI. CONCLUSIONS: Delaying resuscitation is associated with both higher volumes of crystalloid by 48 hours and worse outcomes compared with early resuscitation. Judicious crystalloid given early in ICU admission could improve outcomes in the severely injured.

Twenty percent human albumin solution fluid bolus administration therapy in patients after cardiac surgery-II: a multicentre randomised controlled trial.

PURPOSE: After cardiac surgery, fluid bolus therapy (FBT) with 20% human albumin may facilitate less fluid and vasopressor administration than FBT with crystalloids. We aimed to determine whether, after cardiac surgery, FBT with 20% albumin reduces the duration of vasopressor therapy compared with crystalloid FBT. METHODS: We conducted a multicentre, parallel-group, open-label, randomised clinical trial in six intensive care units (ICUs) involving cardiac surgery patients deemed to require FBT. We randomised 240 patients to receive up to 400 mL of 20% albumin/day as FBT, followed by 4% albumin for any subsequent FBT on that day, or to crystalloid FBT for at least the first 1000 mL, with use of crystalloid or 4% albumin FBT thereafter. The primary outcome was the cumulative duration of vasopressor therapy. Secondary outcomes included fluid balance. RESULTS: Of 480 randomised patients, 466 provided consent and contributed to the primary outcome (mean age 65 years; median EuroSCORE II 1.4). The cumulative median duration of vasopressor therapy was 7 (interquartile range [IQR] 0-19.6) hours with 20% albumin and 10.8 (IQR 0-22.8) hours with crystalloids (difference - 3.8 h, 95% confidence interval [CI] - 8 to 0.4; P = 0.08). Day one fluid balance was less with 20% albumin FBT (mean difference - 701 mL, 95% CI - 872 to - 530). CONCLUSIONS: In patients after cardiac surgery, when compared to a crystalloid-based FBT, 20% albumin FBT was associated with a reduced positive fluid balance but did not significantly reduce the duration of vasopressor therapy.

Aporte de fluidos en el pacientes pediátricos hospitalizados / Fluid intake in hospitalized pediatric patients

El aporte de fluidos constituye un elemento central en la atención del paciente pediátrico hospitalizado, existiendo aún controversias acerca de cuál es la composición óptima, la dosis adecuada y la mejor estrategia para administrar los mismos. El propósito de este artículo de actualización es brindar al médico que se desempeña en las diferentes áreas de la internación pediátrica, conceptos y enfoques terapéuticos que lo ayuden en la asistencia de los pacientes que por diversos motivos requieren la administración de fluidos endovenosos. La recomendación de utilizar cristaloides en la reanimación es casi uniforme. Se observa una clara tendencia al uso de soluciones isotónicas balanceadas para la reposición del déficit previo y el aporte de fluidos de mantenimiento. En relación a la dosis y a la estrategia, es generalizada la recomendación de un enfoque más restrictivo en el aporte de volumen, aún en los pacientes con shock, donde es necesario lograr un balance entre una resucitación efectiva y el riesgo de sobrecarga de fluidos. Respecto a la administración de albúmina al 20% en el paciente crítico con hipoalbuminemia, la evidencia existente es escasa y no permite formular recomendaciones. Sin embargo, es frecuente su uso en la práctica asistencial

Intravenous fluids administration is a central element in the care of hospitalized pediatric patients, and there are still controversies about what is the optimal composition, the appropriate dose, and the best strategy for their administration. The purpose of this narrative review is to provide the physicians who works in the different areas of pediatric hospitalization, concepts and therapeutic approaches that help them in the care of patients who for diverse reasons require administration of intravenous fluids. The recommendation to use crystalloids in resuscitation is almost uniform. There is a clear trend towards the use of balanced isotonic solutions to replace the previous deficit and the supply of maintenance fluids. In relation to the dose and strategy, the recommendation of a more restrictive approach in volume administration is generalized, even in patients with shock, where it is necessary to strike a balance between effective resuscitation and the risk of fluid overload. Regarding the administration of 20% albumin in critically ill patients with hypoalbuminemia, the existing evidence is scarce and does not allow recommendations to be formulated. However, it is frequently used in healthcare practice

Comparative ultrasound study of gastric emptying between an isotonic solution and a nutritional supplement / Estudo comparativo do esvaziamento gástrico entre uma solução isotônica e um suplemento nutricional por meio da ultrassonografia

Abstract Background and objectives: Preoperative fasting may lead to undesirable effects in the surgical patient in whom there is a stimulus to ingesting clear liquids until 2 hours before anesthesia. The aim of this study was to evaluate the gastric emptying of two different solutions using ultrasound. Methods: In a prospective, randomized, blind study, 34 healthy volunteers ingested 200 mL of two solutions without residues in two steps: an isotonic solution with carbohydrates, electrolytes, osmolarity of 292 mOsm.L-1, and 36 kcal; and other nutritional supplementation with carbohydrates, proteins, electrolytes, osmolarity of 680 mO.L-1, and 300 kcal. After 2 hours, a gastric ultrasound was performed to assess the antrum area and gastric volume, and the relation of gastric volume to weight (vol.w-1), whose value above 1.5 mL.kg-1 was considered a risk for bronchoaspiration. A p-value <0.05 was considered statistically significant. Results: There was a significant difference between all parameters evaluated 2 hours after the ingestion of nutritional supplementation compared to fasting. The same occurred when the parameters between isotonic solution and nutritional supplementation were compared 2 hours after ingestion. Only one patient had vol.w-1 <1.5 mL.kg-1 2 hours after ingestion of nutritional supplementation; and only one had vol.w-1 >1.5 mL.kg-1 after ingestion of isotonic solution. Conclusion: This study demonstrated that gastric emptying of equal volumes of different solutions depends on their constitution. Those with high caloric and high osmolarity, and with proteins present, 2 hours after ingestion, increased the gastric volumes, which is compatible with the risk of gastric aspiration.

Resumo Justificativa e objetivos: O jejum pré-operatório pode levar a efeitos indesejáveis no paciente cirúrgico, em que há um estimulo à ingestão de líquidos sem resíduos até 2 horas antes da anestesia. O objetivo deste estudo foi avaliar o esvaziamento gástrico de duas soluções diferentes por meio da ultrassonografia. Métodos: Em um estudo prospectivo, randomizado, cego, 34 voluntários saudáveis ingeriram 200 mL de duas soluções sem resíduos, em duas etapas: uma solução isotônica com carboidratos, eletrólitos, osmolaridade de 292 mOsm.L-1 e 36 kcal; e outra suplementação nutricional, com carboidratos, proteínas, eletrólitos, osmolaridade de 680 mOs.L-1 e 300 kcal. Após 2 horas, fez-se ultrassonografia gástrica com avaliação da área do antro e volume gástrico e relação do volume gástrico sobre o peso (vol.p-1), cujo valor acima de 1,5 mL.kg-1 foi considerado risco para broncoaspiração. Considerou-se p< 0,05 como estatisticamente significativo. Resultados: Houve diferença significativa entre todos os parâmetros avaliados 2 horas após a ingestão de suplementação nutricional em relação ao jejum. O mesmo ocorreu quando foram comparados os parâmetros entre solução isotônica e suplementação nutricional 2 horas após a ingestão. Apenas um paciente apresentou vol.p-1< 1,5 mL.kg-1 2 horas após a ingestão de suplementação nutricional; e apenas um apresentou vol.p-1 > 1,5 mL.kg-1, após a ingestão de solução isotônica. Conclusão: Este estudo demonstrou que o esvaziamento gástrico de volumes iguais de diferentes soluções depende de sua constituição. Aqueles com alto valor calórico e alta osmolaridade, e com proteínas presentes, 2 horas após a ingestão, aumentaram os volumes gástricos, compatíveis com o risco de aspiração gástrica.

Comparación entre hidratación con leche chocolatada descremada y bebida deportiva posterior al ejercicio físico en militares / Comparison between hydration with chocolate skim milk and sports drink after physical exercise in militaries

Introducción: dos factores importantes han sido descritos como contribuyentes en la aparición de fatiga durante el ejercicio físico: la disminución de las reservas de glucógeno muscular y la pérdida de agua con electrolitos a través del sudor, que favorecen la deshidratación. Debido a esto, la reposición de líquidos y electrolitos posterior al ejercicio físico se transforma en la prioridad para restablecer la homeostasis corporal alterada durante el ejercicio físico. Por su composición nutricional, la leche parece ser una buena alternativa natural como bebida rehidratante posterior al ejercicio físico. Objetivo: comparar la efectividad como bebida de rehidratación de la leche descremada chocolatada contra una bebida deportiva artificial en militares, a partir de la hipótesis de que la leche descremada chocolatada tiene iguales o mejores efectos sobre la hidratación post ejercicio, que una bebida deportiva artificial. Método: 30 militares (23,0 ± 3,2 años) se dividieron en 2 grupos: 1) rehidratación con bebida deportiva con 6 pòr ciento de carbohidratos y relación de Na/K 2:1 (grupo ISO). Rehidratación con leche descremada chocolatada (grupo LECHE). Se evaluó la retención de fluidos a través del peso corporal y la gravedad específica de la orina (GEO) antes y después del ejercicio físico y posterior a las 2 horas de rehidratación. Resultados: se encontraron diferencias significativas (p< 0,05) en la retención de fluidos en el grupo LECHE comparado con el grupo ISO. No hubo diferencias significativas entre la GEO de ambos grupos. Conclusión: Los resultados muestran que la rehidratación con leche descremada es más efectiva en la retención de fluidos y recuperación del peso previo al ejercicio que la bebida deportiva(AU)

ntroduction: Two important factors have been described as contributing to the onset of fatigue during physical exercise: Decreased muscle glycogen stores and the loss of water with electrolytes through sweating, favoring dehydration. Because of this, fluid and electrolyte replacement after physical exercise becomes the priority to restore altered body homeostasis during physical exercise. Due to its nutritional composition, milk appears to be a good natural alternative as a rehydration beverage after exercise. Objective: To compare the effectiveness chocolate skim milk as pots-exercise rehydration beverage with an artificial sports drink in the military, based on the hypothesis that chocolate skim milk has equal or better effects on post-exercise hydration than an artificial sports drink. Method: 30 soldiers (23.0 ± 3.2 years) were divided into 2 groups: 1) rehydration with sports drink with 6 percent carbohydrates and ratio of Na / K 2: 1 (ISO group). Rehydration with chocolate skim milk (LECHE group). Fluid retention was assessed through body weight and the specific gravity of urine (GEO) before and after physical exercise and after 2 hours of rehydration. Results: significant differences were found (p < 0.05) in fluid retention in the LECHE group compared to the ISO group. There were no significant differences between the GEO of both groups. Conclusion: The results show that rehydration with skim milk is more effective in fluid retention and weight recovery prior to exercise than sports drink(AU)

Use of ultrasound for gastric volume evaluation after ingestion of different volumes of isotonic solution / Uso da ultrassonografia para avaliação do volume gástrico após ingestão de diferentes volumes de solução isotônica

Abstract Background and objectives: The current preoperative fasting guidelines allow fluid intake up to 2 h before surgery. The aim of this study was to evaluate the gastric volume of volunteers after an overnight fast and compare it with the gastric volume 2 h after ingestion of 200 and 500 mL of isotonic solution, by means of ultrasound assessment. Method: Eighty volunteers underwent gastric ultrasound at three times: after 8 h of fasting; 2 h after ingestion of 200 mL isotonic saline, followed by the first scan; and on another day, 2 h after ingestion of 500 mL of the same solution after an overnight fast. The evaluation was quantitative (antrum area and gastric volume, and the ratio of participants' gastric volume/weight) and qualitative (absence or presence of gastric contents on right lateral decubitus and supine positions. A p-value < 0.05 was considered significant). Results: There was no difference in quantitative variables at measurement times (p > 0.05). Five volunteers (6.25%) had a volume/weight over 1.5 mL kg-1 at fasting and 2 h after ingestion of 200 mL and 6 (7.5%) after 500 mL. Qualitatively, the presence of gastric fluid occurred in more volunteers after fluid ingestion, especially 500 mL (18.7%), although not statistically significant. Conclusion: Ultrasound assessment of gastric volume showed no significant difference, both qualitative and quantitative, 2 h after ingestion of 200 mL or 500 mL of isotonic solution compared to fasting, although gastric fluid content has been identified in more volunteers, especially after ingestion of 500 mL isotonic solution.

Resumo Justificativa e objetivos: As diretrizes recentes de jejum pré-operatório permitem a ingestão de líquidos até 2 horas antes da cirurgia. O objetivo do presente estudo foi, por meio de ultrassonografia gástrica, avaliar o volume gástrico de voluntários após jejum noturno e comparar com o volume gástrico duas horas após a ingestão de 200 e 500 ml de solução isotônica. Método: Foram submetidos à ultrassonografia gástrica 80 voluntários em três momentos: após jejum de 8 horas; 2 horas após a ingestão de 200 ml de solução isotônica, seguida do primeiro exame; e, em outro dia, 2 horas após a ingestão de 500 ml da mesma solução, após jejum noturno. A avaliação foi quantitativa (área do antro e volume gástricos e relação volume gástrico/peso dos participantes) e qualitativa, pela ausência ou presença de conteúdo gástrico nas posições de decúbito lateral direito e supina. Foi considerado significante p < 0,05. Resultados: Não houve diferença nas variáveis quantitativas nos três momentos estudados (p > 0,05). Cinco voluntários (6,25%) apresentaram um volume/peso superior a 1,5 ml.kg-1 em jejum e 2 horas após a ingestão de 200 ml e seis (7,5%) após 500 ml. Qualitativamente, a presença de líquido gástrico ocorreu em mais voluntários após a ingestão de líquidos, principalmente de 500 ml (18,7%), embora sem significância estatística. Conclusão: O volume gástrico pela ultrassonografia não apresenta diferença significativa tanto qualitativa quanto quantitativa, 2 horas após a ingestão de 200 ml ou de 500 ml de solução isotônica em comparação com o jejum, embora conteúdo líquido gástrico tenha sido identificado em mais voluntários, principalmente após a ingestão de 500 ml de solução isotônica.

Cristaloides balanceados para ressuscitação do choque séptico / Balanced crystalloids for septic shock resuscitation

RESUMO A administração de fluidos em tempo adequado é crucial para a manutenção da perfusão tissular nos pacientes com choque séptico. Entretanto, a questão da escolha do fluido a ser utilizado para ressuscitação no choque séptico ainda é um assunto em debate. É crescente o corpo de evidência que sugere que o tipo, a quantidade e o momento da administração de fluidos durante a evolução da sepse podem afetar os desfechos do paciente. Os cristaloides têm sido recomendados como fluidos a serem administrados em primeira linha na ressuscitação do choque. No entanto, à luz da natureza inconclusiva da literatura disponível, não se podem fazer recomendações definitivas quanto à solução cristaloide mais apropriada. A ressuscitação de pacientes críticos sépticos e não sépticos com cristaloides não balanceados, principalmente a solução salina a 0,9%, tem sido associada a uma maior incidência de desordens do equilíbrio ácido-base e a distúrbios eletrolíticos, além de poder se associar à maior incidência de lesão renal aguda, à maior necessidade de terapia de substituição renal e à mortalidade. Foi proposto o uso de soluções cristaloides balanceadas como uma alternativa às soluções de cristaloides não balanceados, para mitigar seus efeitos deletérios. Entretanto, a segurança e a eficácia dos cristaloides balanceados para ressuscitação do choque séptico necessitam ser mais bem exploradas em estudos clínicos bem delineados, randomizados e controlados, multicêntricos e pragmáticos.

ABSTRACT Timely fluid administration is crucial to maintain tissue perfusion in septic shock patients. However, the question concerning which fluid should be used for septic shock resuscitation remains a matter of debate. A growing body of evidence suggests that the type, amount and timing of fluid administration during the course of sepsis may affect patient outcomes. Crystalloids have been recommended as the first-line fluids for septic shock resuscitation. Nevertheless, given the inconclusive nature of the available literature, no definitive recommendations about the most appropriate crystalloid solution can be made. Resuscitation of septic and non-septic critically ill patients with unbalanced crystalloids, mainly 0.9% saline, has been associated with a higher incidence of acid-base balance and electrolyte disorders and might be associated with a higher incidence of acute kidney injury. This can result in greater demand for renal replacement therapy and increased mortality. Balanced crystalloids have been proposed as an alternative to unbalanced solutions in order to mitigate their detrimental effects. Nevertheless, the safety and effectiveness of balanced crystalloids for septic shock resuscitation need to be further addressed in a well-designed, multicenter, pragmatic, randomized controlled trial.

Colloids versus crystalloids in objective-guided fluid therapy, systematic review and meta-analysis. Too early or too late to draw conclusions / Coloides versus cristaloides em fluidoterapia guiada por objetivos, revisão sistemática e metanálise. Demasiadamente cedo ou demasiadamente tarde para obter conclusões / Coloides versus cristaloides en fluidoterapia guiada por objetivos, revisión sistemática y metaanálisis. Demasiado pronto o demasiado tarde para obtener conclusiones

Several clinical trials on Goal directed fluid therapy (GDFT) were carried out, many of those using colloids in order to optimize the preload. After the decision of European Medicines Agency, there is such controversy regarding its use, benefits, and possible contribution to renal failure. The objective of this systematic review and meta-analysis is to compare the use of last-generation colloids, derived from corn, with crystalloids in GDFT to determine associated complications and mortality.

Foram feitos múltiplos ensaios clínicos em fluidoterapia guiada por objetivos (FGO), muitos deles com o uso de coloides para aprimoramento da pré-carga. Após a decisão da Agência Europeia de Medicamentos, existe ainda controvérsia sobre seu uso, seus benefícios e sua possível contribuição para a falência renal. O objetivo desta revisão sistemática e metanálise é comparar o uso de coloides de última geração, derivados de milho, com cristaloides em FGO para determinar as complicações e a mortalidade associadas.

Se han realizado múltiples ensayos clínicos en fluidoterapia guiada por objetivos (FGO), muchos de ellos con el uso de coloides para la optimización de la precarga. Tras la decisión de la Agencia Europea del Medicamento, existe cierta controversia en cuanto a su utilización, beneficios y su posible contribución al fallo renal. El objetivo de esta revisión sistemática y metaanálisis es comparar el uso de coloides de última generación, derivados del maíz, con cristaloides en FGO para determinar las complicaciones y la mortalidad asociadas.

Comparison of two maintenance electrolyte solutions in children in the postoperative appendectomy period: a randomized, controlled trial / Comparação de duas soluções para manutenção hidroeletrolítica no pós-operatório de apendicectomia em crianças: um estudo controlado e randomizado

ABSTRACT OBJECTIVE: To compare two electrolyte maintenance solutions in the postoperative period in children undergoing appendectomy, in relation to the occurrence of hyponatremia and water retention. METHODS: A randomized clinical study involving 50 pediatric patients undergoing appendectomy, who were randomized to receive 2,000 mL/m2/day of isotonic (Na 150 mEq/L or 0.9% NaCl) or hypotonic (Na 30 mEq/L NaCl or 0.18%) solution. Electrolytes, glucose, urea, and creatinine were measured at baseline, 24 h, and 48 h after surgery. Volume infused, diuresis, weight, and water balance were analyzed. RESULTS: Twenty-four patients had initial hyponatremia; in this group, 13 received hypotonic solution. Seventeen patients remained hyponatremic 48 h after surgery, of whom ten had received hypotonic solution. In both groups, sodium levels increased at 24 h (137.4 ± 2.2 and 137.0 ± 2.7 mmol/L), with no significant difference between them (p = 0.593). Sodium levels 48 h after surgery were 136.6 ± 2.7 and 136.2 ± 2.3 mmol/L in isotonic and hypotonic groups, respectively, with no significant difference. The infused volume and urine output did not differ between groups during the study. The water balance was higher in the period before surgery in patients who received hypotonic solution (p = 0.021). CONCLUSIONS: In the post-appendectomy period, the use of hypotonic solution (30 mEq/L, 0.18%) did not increase the risk of hyponatremia when compared to isotonic saline. The use of isotonic solution (150 mEq/L, 0.9%) did not favor hypernatremia in these patients. Children who received hypotonic solution showed higher cumulative fluid balance in the preoperative period.

RESUMO OBJETIVO: Comparar duas soluções de manutenção hidroeletrolítica no período pós-operatório (PO) de crianças submetidas à apendicectomia quanto à ocorrência de hiponatremia e retenção hídrica. MÉTODOS: Estudo clínico randomizado que envolveu 50 pacientes pediátricos submetidos à apendicectomia, randomizados para receber 2.000 ml/m2/dia de solução isotônica (Na 150 mEq/L ou NaCl 0,9%) ou hipotônica (Na 30mEq/L ou NaCl 0,18%). Eletrólitos, glicose, ureia e creatinina foram mensurados no início do estudo, 24 e 48 horas após a cirurgia. Foram analisados volume infundido, diurese, peso e balanço hídrico. RESULTADOS: Apresentaram hiponatremia inicial 24 pacientes. Desses, 13 receberam solução hipotônica. Dezessete pacientes permaneceram hiponatrêmicas 48 horas após a cirurgia, 10 haviam recebido solução hipotônica. Nos dois grupos os níveis de sódio aumentaram na 24ª hora PO (137,4 ± 2,2 e 137,0 ± 2,7) e não houve diferença entre eles (p = 0,593). Níveis de sódio 48 h após a cirurgia foram 136,6 ± 2,7 e 136,2 ± 2,3 no grupo isotônico e hipotônico respectivamente sem diferença significativa. Os volumes infundidos e a diurese não diferiram entre os grupos durante o estudo. O balanço hídrico foi maior no período anterior à cirurgia no grupo de pacientes que receberam solução hipotônica (p = 0,021). CONCLUSÕES: No período pós-apendicectomia, o uso da solução hipotônica não aumentou o risco de hiponatremia quando comparado com uma solução salina isotônica. O uso da solução isotônica não favoreceu a hipernatremia nesses pacientes. Crianças que receberam solução hipotônica apresentaram maior balanço hídrico cumulativo no período pré-operatório.

Animal model of rapid crystalloid infusion in rats

PURPOSE: To describe an animal model of rapid intravenous infusion with different volumes of crystalloid and discuss the clinical findings. METHODS: Fifty six male Wistar rats were used, divided randomly in seven groups (n = 8). The rats of groups 1 to 6 received lactated Ringer´s solution intravenously, in the rate of 25 ml/min, with different volumes proportional to blood volume (BV). The rats of group 0 were submitted to the same procedure, but did not receive the fluid (control group). The data included respiratory rate, heart rate, saturation of peripheral oxygen (SpO2) in two times (before and after the infusion), and upshots (respiratory arrest and death). Dunnett´s test and ANOVA were used. RESULTS: The clinical signs significantly changed in the 2, 2.5 and 3 fold BV groups. The respiratory arrest was observed in the 1.5, 2, 2.5 and 3 fold BV groups, but death was present only in 2.5 and 3 fold BV groups. CONCLUSIONS: The infusion of crystalloid in the same volume of blood volume did not cause significant variation in respiratory and heart rate, saturation of peripheral oxygen and did not induce respiratory arrest. The infusion of a volume of 3 fold blood volume was lethal to all animals.