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2.
Am J Physiol Renal Physiol ; 319(6): F1090-F1104, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33166183

RESUMO

Sodium bicarbonate (NaHCO3) has been recognized as a possible therapy to target chronic kidney disease (CKD) progression. Several small clinical trials have demonstrated that supplementation with NaHCO3 or other alkalizing agents slows renal functional decline in patients with CKD. While the benefits of NaHCO3 treatment have been thought to result from restoring pH homeostasis, a number of studies have now indicated that NaHCO3 or other alkalis may provide benefit regardless of the presence of metabolic acidosis. These data have raised questions as to how NaHCO3 protects the kidneys. To date, the physiological mechanism(s) that mediates the reported protective effect of NaHCO3 in CKD remain unclear. In this review, we first examine the evidence from clinical trials in support of a beneficial effect of NaHCO3 and other alkali in slowing kidney disease progression and their relationship to acid-base status. Then, we discuss the physiological pathways that have been proposed to underlie these renoprotective effects and highlight strengths and weaknesses in the data supporting each pathway. Finally, we discuss how answering key questions regarding the physiological mechanism(s) mediating the beneficial actions of NaHCO3 therapy in CKD is likely to be important in the design of future clinical trials. We conclude that basic research in animal models is likely to be critical in identifying the physiological mechanisms underlying the benefits of NaHCO3 treatment in CKD. Gaining an understanding of these pathways may lead to the improved implementation of NaHCO3 as a therapy in CKD and perhaps other disease states.


Assuntos
Equilíbrio Ácido-Base/efeitos dos fármacos , Acidose/tratamento farmacológico , Álcalis/uso terapêutico , Rim/efeitos dos fármacos , Insuficiência Renal Crônica/tratamento farmacológico , Bicarbonato de Sódio/uso terapêutico , Acidose/metabolismo , Acidose/fisiopatologia , Álcalis/efeitos adversos , Taxa de Filtração Glomerular/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Rim/metabolismo , Rim/fisiopatologia , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/fisiopatologia , Bicarbonato de Sódio/efeitos adversos , Resultado do Tratamento
3.
Adv Physiol Educ ; 44(4): 706-708, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33079564

RESUMO

Understanding and interpretation of acid-base disorders is an important clinical skill that is applicable to the majority of physicians. Although this topic is taught early in medical school, acid-base disturbances have been described as challenging by postgraduate trainees. We describe the use of Twitter, an online microblogging platform, to augment education in acid-base disturbances by using polls in which the user is shown laboratory values and then asked to select the most likely etiology of the disorder. The answer and a brief explanation are then shared in a subsequent tweet. Both polling questions and answers are shared from the account for the online, mobile-optimized, nephrology teaching tool NephSIM (https://www.nephsim.com/). An anonymous survey was administered to assess attitudes toward these polls. Using Twitter as an approach to enhance teaching of acid-base disturbances was both feasible and an engaging way to teach a challenging topic for trainees and physicians. Moreover, the coronavirus disease 2019 (COVID-19) pandemic has demonstrated the importance of incorporating virtual learning opportunities in all levels of medical education.


Assuntos
Equilíbrio Ácido-Base , Desequilíbrio Ácido-Base/etiologia , Comportamento de Escolha , Instrução por Computador , Educação a Distância , Educação de Graduação em Medicina/métodos , Fisiologia/educação , Mídias Sociais , Desequilíbrio Ácido-Base/diagnóstico , Desequilíbrio Ácido-Base/fisiopatologia , Compreensão , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Currículo , Escolaridade , Humanos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Quarentena
4.
Am J Physiol Renal Physiol ; 319(6): F1081-F1089, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32996319

RESUMO

Early acclimatization to high altitude is characterized by various respiratory, hematological, and cardiovascular adaptations that serve to restore oxygen delivery to tissue. However, less is understood about renal function and the role of renal oxygen delivery (RDO2) during high altitude acclimatization. We hypothesized that 1) RDO2 would be reduced after 12 h of high altitude exposure (high altitude day 1) but restored to sea level values after 1 wk (high altitude day 7) and 2) RDO2 would be associated with renal reactivity, an index of acid-base compensation at high altitude. Twenty-four healthy lowlander participants were tested at sea level (344 m, Kelowna, BC, Canada) and on day 1 and day 7 at high altitude (4,330 m, Cerro de Pasco, Peru). Cardiac output, renal blood flow, and arterial and venous blood sampling for renin-angiotensin-aldosterone system hormones and NH2-terminal pro-B-type natriuretic peptides were collected at each time point. Renal reactivity was calculated as follows: (Δarterial bicarbonate)/(Δarterial Pco2) between sea level and high altitude day 1 and sea level and high altitude day 7. The main findings were that 1) RDO2 was initially decreased at high altitude compared with sea level (ΔRDO2: -22 ± 17%, P < 0.001) but was restored to sea level values on high altitude day 7 (ΔRDO2: -6 ± 14%, P = 0.36). The observed improvements in RDO2 resulted from both changes in renal blood flow (Δ from high altitude day 1: +12 ± 11%, P = 0.008) and arterial oxygen content (Δ from high altitude day 1: +44.8 ± 17.7%, P = 0.006) and 2) renal reactivity was positively correlated with RDO2 on high altitude day 7 (r = 0.70, P < 0.001) but not high altitude day 1 (r = 0.26, P = 0.29). These findings characterize the temporal responses of renal function during early high altitude acclimatization and the influence of RDO2 in the regulation of acid-base balance.


Assuntos
Aclimatação , Altitude , Rim/metabolismo , Consumo de Oxigênio , Oxigênio/metabolismo , Equilíbrio Ácido-Base , Adulto , Feminino , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
5.
Am J Physiol Renal Physiol ; 319(4): F712-F728, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32893663

RESUMO

Inhibitors of proximal tubular Na+-glucose cotransporter 2 (SGLT2) are natriuretic, and they lower blood pressure. There are reports that the activities of SGLT2 and Na+-H+ exchanger 3 (NHE3) are coordinated. If so, then part of the natriuretic response to an SGLT2 inhibitor is mediated by suppressing NHE3. To examine this further, we compared the effects of an SGLT2 inhibitor, empagliflozin, on urine composition and systolic blood pressure (SBP) in nondiabetic mice with tubule-specific NHE3 knockdown (NHE3-ko) and wild-type (WT) littermates. A single dose of empagliflozin, titrated to cause minimal glucosuria, increased urinary excretion of Na+ and bicarbonate and raised urine pH in WT mice but not in NHE3-ko mice. Chronic empagliflozin treatment tended to lower SBP despite higher renal renin mRNA expression and lowered the ratio of SBP to renin mRNA, indicating volume loss. This effect of empagliflozin depended on tubular NHE3. In diabetic Akita mice, chronic empagliflozin enhanced phosphorylation of NHE3 (S552/S605), changes previously linked to lesser NHE3-mediated reabsorption. Chronic empagliflozin also increased expression of genes involved with renal gluconeogenesis, bicarbonate regeneration, and ammonium formation. While this could reflect compensatory responses to acidification of proximal tubular cells resulting from reduced NHE3 activity, these effects were at least in part independent of tubular NHE3 and potentially indicated metabolic adaptations to urinary glucose loss. Moreover, empagliflozin increased luminal α-ketoglutarate, which may serve to stimulate compensatory distal NaCl reabsorption, while cogenerated and excreted ammonium balances urine losses of this "potential bicarbonate." The data implicate NHE3 as a determinant of the natriuretic effect of empagliflozin.


Assuntos
Compostos Benzidrílicos/farmacologia , Diabetes Mellitus/tratamento farmacológico , Glucosídeos/farmacologia , Túbulos Renais Proximais/efeitos dos fármacos , Natriurese/efeitos dos fármacos , Natriuréticos/farmacologia , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Transportador 2 de Glucose-Sódio/metabolismo , Trocador 3 de Sódio-Hidrogênio/metabolismo , Equilíbrio Ácido-Base/efeitos dos fármacos , Animais , Glicemia/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Diabetes Mellitus/metabolismo , Diabetes Mellitus/fisiopatologia , Modelos Animais de Doenças , Glicosúria/metabolismo , Glicosúria/fisiopatologia , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação , Trocador 3 de Sódio-Hidrogênio/deficiência , Trocador 3 de Sódio-Hidrogênio/genética
6.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 32(8): 976-981, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32912413

RESUMO

OBJECTIVE: To judge the type of acid-base balance disorder automatically according to the results of arterial blood gas analysis by using the IF function editing formula in an Excel spreadsheet. METHODS: The four-step analysis was used to carry out programmatically through establishing acid-base balance disorder analysis process: (1) the acid and base types were determined according to pH value and the primary or main type of acid-base balance disorder was determined according to the pH value combined with blood carbon dioxide pressure (PaCO2), HCO3- and their change rate; (2) the expected compensation formula was selected to determine whether there was mixed acid-base imbalance, according to the primary or main acid-base imbalance type; (3) the potential HCO3- should be calculated to replace the measured HCO3- when the primary acid-base imbalance was divided into two parts according to the prior two steps: respiratory acidosis or respiratory alkalosis accompanied with anion gap (AG) increased-metabolic acidosis and compared with the compensatory interval calculated by the predicted compensatory formula for acid or alkali to determine whether there were triple acid-base imbalance (TABD); (4) while the following two parts were judged: metabolic acidosis accompanied with AG increased-metabolic acidosis according to the prior two steps, ΔAG↑/ΔHCO3-↓ should be calculated to determine whether there was metabolic alkalosis or metabolic acidosis with normal AG. The results of arterial blood gas analysis were judged by using the editing formula of IF function in Excel 2003 spreadsheet. A total of 96 patients admitted to the department of intensive care unit (ICU) of Xuzhou Central Hospital were enrolled. According to the results of arterial blood gas analysis, the type of acid-base imbalance of patients was judged by both artificial judgment (artificial group) and Excel spreadsheet automatic judgment (Excel spreadsheet group). The artificial group was composed by 2 associate chief physicians from neonatal intensive care unit (NICU) and 1 attending respiratory physician. If the results were inconsistent, the decision should be made after discussion. In the Excel spreadsheet group, data were input by one NICU attending physician and checked by another. The differences in the results and the time spent in judging the type of acid-base imbalance between the two groups were compared. RESULTS: Forty-two types of acid-base imbalance were obtained by using the four-step analysis method and inputting relevant parameters such as pH, PaCO2, actual HCO3-, Na+, Cl- and compensation time limited into the Excel spreadsheet for blood gas analysis. Data analyses of 96 patients showed that the accuracy of using Excel spreadsheets to automatically determine the type of acid-base imbalance was higher than artificial group, but there was no statistically significant difference between the two groups [normal and simple acid-base imbalance: 100% (26/26) vs. 100% (26/26), mixed acid-base imbalance: 100% (51/51) vs. 96.08% (49/51), TABD: 100% (19/19) vs. 89.47% (17/19), all P > 0.05], and it took less time to judge the results of blood gas analysis by the Excel spreadsheet group compared with the artificial group (s: normal and simple acid-base imbalance: 31.13±4.70 vs. 74.20±16.53, mixed acid-base imbalance: 31.59±5.49 vs. 138.10±22.26, TABD: 30.98±5.40 vs. 308.40±78.12, all P < 0.01). CONCLUSIONS: The automatic judging Excel spreadsheet with blood gas analysis can quickly and accurately determine the type of acid-base imbalance in arterial blood gas analysis.


Assuntos
Desequilíbrio Ácido-Base , Gasometria , Equilíbrio Ácido-Base , Alcalose , Alcalose Respiratória , Humanos , Software
7.
Ann Biol Clin (Paris) ; 78(4): 417-424, 2020 08 01.
Artigo em Francês | MEDLINE | ID: mdl-32753366

RESUMO

We present the case of a four-year-old girl, who was hospitalized in intensive care unit for a coma resulting from metabolic acidosis with increased anion gap. The patient was treated for short bowel syndrome, following necrotising enterocolitis, which occurred 51 days after birth. In our initial evaluation of the patient's metabolic acidosis, we were unable to identify the cause of the increased anion gap. Urinary organic acids chromatography identified a large peak of lactate (quantified at 15 mmol/mol of creatiniuria), as well as its metabolites. The discrepancy between normal blood lactate concentration assayed by enzymatic assay, and the large amount of lactate found by gas-chromatography/mass spectrometry (GC/MS) in urine highlights the limit of the stereospecificity of enzymatic assays. Indeed, most lactates assay use enzymatic assays that are specific for L-lactate, whereas organic acids chromatography, whose column is mostly achiral, can detect both stereoisomers, D- and L-lactate. Organic acids in urine analysis, in addition to the clinical context, suggested a diagnosis of D-lactic acidosis. Following a review of the physiopathology and treatment of short bowel syndrome, we will discuss the mechanism and diagnosis of the D-lactic acidosis in our patient. This case highlights the need to perform an organic acid profile in urine in the presence of any unexplained increased anion gap to determine its cause.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Acidose Láctica/diagnóstico , Acidose/diagnóstico , Coma/diagnóstico , Síndrome do Intestino Curto/diagnóstico , Acidose/etiologia , Acidose/metabolismo , Acidose Láctica/etiologia , Acidose Láctica/metabolismo , Acidose Láctica/urina , Análise Química do Sangue/métodos , Pré-Escolar , Coma/sangue , Coma/etiologia , Coma/urina , Diagnóstico Diferencial , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Ácido Láctico/sangue , Ácido Láctico/urina , Síndrome do Intestino Curto/complicações , Síndrome do Intestino Curto/metabolismo , Urinálise
8.
Sci Rep ; 10(1): 13732, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792614

RESUMO

This investigation assessed the course of renal compensation of hypoxia-induced respiratory alkalosis by elimination of bicarbonate ions and impairments in anaerobic exercise after different durations of hypoxic exposure. Study A: 16 participants underwent a resting 12-h exposure to normobaric hypoxia (3,000 m). Blood gas analysis was assessed hourly. While blood pH was significantly increased, PO2, PCO2, and SaO2 were decreased within the first hour of hypoxia, and changes remained consistent. A substantial reduction in [HCO3-] levels was observed after 12 h of hypoxic exposure (- 1.35 ± 0.29 mmol/L, p ≤ 0.05). Study B: 24 participants performed in a randomized, cross-over trial portable tethered sprint running (PTSR) tests under normoxia and after either 1 h (n = 12) or 12 h (n = 12) of normobaric hypoxia (3,000 m). No differences occurred for PTSR-related performance parameters, but the reduction in blood lactate levels was greater after 12 h compared with 1 h (- 1.9 ± 2.2 vs 0.0 ± 2.3 mmol/L, p ≤ 0.05). These results indicate uncompensated respiratory alkalosis after 12 h of hypoxia and similar impairment of high-intensity exercise after 1 and 12 h of hypoxic exposure, despite a greater reduction in blood lactate responses after 12 h compared with 1 h of hypoxic exposure.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Exercício Físico/fisiologia , Hipóxia/fisiopatologia , Adulto , Alcalose/metabolismo , Alcalose/fisiopatologia , Altitude , Bicarbonatos/metabolismo , Dióxido de Carbono/metabolismo , Estudos Cross-Over , Feminino , Humanos , Hipóxia/metabolismo , Masculino , Oxigênio/metabolismo , Corrida/fisiologia , Adulto Jovem
10.
Zhonghua Yu Fang Yi Xue Za Zhi ; 54(6): 634-637, 2020 Jun 06.
Artigo em Chinês | MEDLINE | ID: mdl-32842278

RESUMO

There is a lack of a reliable comprehensive evaluation indicator to access the health effects of drinking water. In recent years, scholars established an indicator to evaluate the comprehensive effect of drinking water on the body's acid-base balance. This indicator came from the potential renal acid load (PRAL) of food and named the potential renal acid load of drinking water. It included several typical anions and cations which are widely found in drinking water. This article reviewed the application, advantages, and disadvantages of PRAL in accessing the effect of drinking water on body acidbase metabolism.


Assuntos
Água Potável , Equilíbrio Ácido-Base , Ácidos , Dieta , Rim
11.
Anesthesiology ; 133(4): 892-904, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32639236

RESUMO

BACKGROUND: During the COVID-19 pandemic, ventilator sharing was suggested to increase availability of mechanical ventilation. The safety and feasibility of ventilator sharing is unknown. METHODS: A single ventilator in pressure control mode was used with flow control valves to simultaneously ventilate two patients with different lung compliances. The system was first evaluated using high-fidelity human patient simulator mannequins and then tested for 1 h in two pairs of COVID-19 patients with acute respiratory failure. Patients were matched on positive end-expiratory pressure, fractional inspired oxygen tension, and respiratory rate. Tidal volume and peak airway pressure (PMAX) were recorded from each patient using separate independent spirometers and arterial blood gas samples drawn at 0, 30, and 60 min. The authors assessed acid-base status, oxygenation, tidal volume, and PMAX for each patient. Stability was assessed by calculating the coefficient of variation. RESULTS: The valves performed as expected in simulation, providing a stable tidal volume of 400 ml each to two mannequins with compliance ratios varying from 20:20 to 20:90 ml/cm H2O. The system was then tested in two pairs of patients. Pair 1 was a 49-yr-old woman, ideal body weight 46 kg, and a 55-yr-old man, ideal body weight 64 kg, with lung compliance 27 ml/cm H2O versus 35 ml/cm H2O. The coefficient of variation for tidal volume was 0.2 to 1.7%, and for PMAX 0 to 1.1%. Pair 2 was a 32-yr-old man, ideal body weight 62 kg, and a 56-yr-old woman, ideal body weight 46 kg, with lung compliance 12 ml/cm H2O versus 21 ml/cm H2O. The coefficient of variation for tidal volume was 0.4 to 5.6%, and for PMAX 0 to 2.1%. CONCLUSIONS: Differential ventilation using a single ventilator is feasible. Flow control valves enable delivery of stable tidal volume and PMAX similar to those provided by individual ventilators.


Assuntos
Infecções por Coronavirus/terapia , Pneumonia Viral/terapia , Respiração Artificial/métodos , Ventiladores Mecânicos , Equilíbrio Ácido-Base , Adulto , Pressão Positiva Contínua nas Vias Aéreas , Infecções por Coronavirus/complicações , Estudos de Viabilidade , Feminino , Humanos , Complacência Pulmonar , Masculino , Manequins , Pessoa de Meia-Idade , Oxigênio/sangue , Pandemias , Pneumonia Viral/complicações , Respiração com Pressão Positiva , Respiração Artificial/instrumentação , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/terapia , Espirometria , Volume de Ventilação Pulmonar , Ventiladores Mecânicos/provisão & distribução
12.
Artigo em Inglês | MEDLINE | ID: mdl-32722186

RESUMO

Physical exercise leads to metabolic changes that affect the acid-base balance in skeletal muscles and other tissues. Nutrition is one of the factors that may influence the acid-base balance in the body. Keeping alkaline circumstances in the body is important not only for health and athletic performance in training but also during competition in many sport events. This is especially significant for athletes who practice in sport at the highest level of competition. The aim of the study was to determine the dietary acid-base balance in competitive Lithuanian high-performance athletes, and to evaluate the effect of actual diets of athletes on NEAP (net endogenous acid production), muscle mass and body mineral content during a four-year Olympic cycle. The research participants were 18.1 ± 3.3-year-old Lithuanian high performance athletes (n = 323). The actual diet was investigated using the 24 h recall dietary survey method. The measurements of body composition were performed using BIA (bioelectrical impedance analysis). The potential renal acid load of the diets of athletes (dietary PRAL) and NEAP were calculated. In 10.2% of athletes, NEAP exceeds 100 mEq · day-1 and is on average 126.1 ± 32.7 mEq · day-1. Higher NEAP in athletes is associated with lower muscle mass (ß -1.2% of body weight, p < 0.001) but has no effect on the amount of minerals in the body (ß 0.01% of body weight, p = 0.073). Overall, 25-30% of Lithuanian high-performance athletes use high-protein diets (2.0-4.8 g · kg-1 · day-1) leading to a dietary acid-base imbalance as well as an excessive production of endogenous acids in the body. Athletes are recommended to consume higher amounts of potassium and magnesium. An increase in calcium intake up to 1500 mg per day is recommended. In exceptional cases, periodised nutrition for athletes may involve diets complemented with bicarbonate and/or beta-alanine supplements.


Assuntos
Equilíbrio Ácido-Base , Atletas , Suplementos Nutricionais , Esportes , Adolescente , Dieta , Feminino , Humanos , Masculino , Adulto Jovem
13.
Am J Physiol Renal Physiol ; 319(3): F366-F379, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32657159

RESUMO

Carbonic anhydrase (CAII) binds to the electrogenic basolateral Na+-[Formula: see text] cotransporter (NBCe1) and facilitates [Formula: see text] reabsorption across the proximal tubule. However, whether the inhibition of CAII with acetazolamide (ACTZ) alters NBCe1 activity and interferes with the ammoniagenesis pathway remains elusive. To address this issue, we compared the renal adaptation of rats treated with ACTZ to NH4Cl loading for up to 2 wk. The results indicated that ACTZ-treated rats exhibited a sustained metabolic acidosis for up to 2 wk, whereas in NH4Cl-loaded rats, metabolic acidosis was corrected within 2 wk of treatment. [Formula: see text] excretion increased by 10-fold in NH4Cl-loaded rats but only slightly (1.7-fold) in ACTZ-treated rats during the first week despite a similar degree of acidosis. Immunoblot experiments showed that the protein abundance of glutaminase (4-fold), glutamate dehydrogenase (6-fold), and SN1 (8-fold) increased significantly in NH4Cl-loaded rats but remained unchanged in ACTZ-treated rats. Na+/H+ exchanger 3 and NBCe1 proteins were upregulated in response to NH4Cl loading but not ACTZ treatment and were rather sharply downregulated after 2 wk of ACTZ treatment. ACTZ causes renal [Formula: see text] wasting and induces metabolic acidosis but inhibits the upregulation of glutamine transporter and ammoniagenic enzymes and thus suppresses ammonia synthesis and secretion in the proximal tubule, which prevented the correction of acidosis. This effect is likely mediated through the inhibition of the CA-NBCe1 metabolon complex, which results in cell alkalinization. During chronic ACTZ treatment, the downregulation of both NBCe1 and Na+/H+ exchanger 3, along with the inhibition of ammoniagenesis and [Formula: see text] generation, contributes to the maintenance of metabolic acidosis.


Assuntos
Acetazolamida/farmacologia , Acidose/metabolismo , Amônia/metabolismo , Bicarbonatos/metabolismo , Diuréticos/farmacologia , Rim/efeitos dos fármacos , Acetazolamida/farmacocinética , Equilíbrio Ácido-Base/efeitos dos fármacos , Adaptação Fisiológica , Sistemas de Transporte de Aminoácidos Neutros/genética , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Animais , Cloretos/sangue , Diuréticos/farmacocinética , Eletrólitos/sangue , Regulação da Expressão Gênica/efeitos dos fármacos , Meia-Vida , Rim/metabolismo , Rim/patologia , Masculino , Ratos , Ratos Sprague-Dawley , Urinálise
14.
Artigo em Inglês | MEDLINE | ID: mdl-32674282

RESUMO

This study assesses the status of hydration and the acid-base balance in female handball players in the Polish Second League before and after simulated matches in both indoor (hall) and beach (outdoor) conditions. The values of biochemical indicators useful for describing water-electrolyte management, such as osmolality, hematocrit, aldosterone, sodium, potassium, calcium, chloride and magnesium, were determined in the players' fingertip capillary blood. Furthermore, the blood parameters of the acid-base balance were analysed, including pH, standard base excess, lactate and bicarbonate ion concentration. Additionally, the pH and specific gravity of the players' urine were determined. The level of significance was set at p < 0.05. It was found that both indoor and beach simulated matches caused post-exercise changes in the biochemical profiles of the players' blood and urine in terms of water-electrolyte and acid-base balance. Interestingly, the location of a simulated match (indoors vs. beach) had a statistically significant effect on only two of the parameters measured post-exercise: concentration of calcium ions (lower indoors) and urine pH (lower on the beach). A single simulated game, regardless of its location, directly affected the acid-base balance and, to a smaller extent, the water-electrolyte balance, depending mostly on the time spent physically active during the match.


Assuntos
Equilíbrio Ácido-Base , Esportes , Equilíbrio Hidroeletrolítico , Bicarbonatos , Feminino , Humanos , Concentração Osmolar , Esportes/fisiologia , Adulto Jovem
15.
J S Afr Vet Assoc ; 91(0): e1-e9, 2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-32501015

RESUMO

Synthetic colloids are commonly administered to dogs to treat absolute or relative hypovolaemia. Voluven® (tetrastarch 130/0.4) and Gelofusine® (succinylated gelatin) are available to veterinarians in South Africa. In humans, use of these products has caused acid-base derangements, changes in haematology and impaired haemostasis. We aimed to investigate these effects in healthy normovolaemic dogs. Eight healthy adult beagle dogs underwent a cross-over study, receiving Voluven® or Gelofusine® (10 mL/kg/h for 120 min) once each with a 14-day washout between treatments. Dogs were premedicated with dexmedetomidine (10 µg/kg intramuscularly). Anaesthesia was induced with propofol and the dogs were maintained with isoflurane-in-oxygen. The anaesthetised dogs were connected to a multi-parameter monitor to monitor physiological parameters throughout. Catheters placed in a jugular vein and dorsal metatarsal artery allowed sampling of venous and arterial blood. Blood was collected immediately prior to commencement of colloid infusion, after 60 min infusion and at the end of infusion (120 min) to allow for arterial blood gas analysis, haematology and coagulation testing (activated partial thromboplastin time [aPTT], prothrombin time [PT] and thromboelastography [TEG]). There was no effect, between treatments or over time, on blood pH. The haemoglobin concentration, erythrocyte count and haematocrit decreased significantly over time (all p 0.01), with no differences between treatments, and remained within normal clinical ranges. There were no differences between treatments or over time for the TEG, aPTT and PT tests of haemostasis. At the dose studied, Voluven® and Gelofusine® had comparably negligible effects on blood acid-base balance and coagulation in normovolaemic dogs.


Assuntos
Artérias/fisiologia , Cães/fisiologia , Derivados de Hidroxietil Amido/efeitos adversos , Substitutos do Plasma/efeitos adversos , Poligelina/efeitos adversos , Equilíbrio Ácido-Base , Animais , Gasometria/veterinária , Estudos Cross-Over , Testes Hematológicos/veterinária , Derivados de Hidroxietil Amido/administração & dosagem , Tempo de Tromboplastina Parcial/veterinária , Substitutos do Plasma/administração & dosagem , Poligelina/administração & dosagem , Tempo de Protrombina/veterinária , África do Sul , Tromboelastografia/veterinária
17.
Nat Rev Nephrol ; 16(9): 525-542, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32528189

RESUMO

Traditional dietary recommendations for patients with chronic kidney disease (CKD) focus on the quantity of nutrients consumed. Without appropriate dietary counselling, these restrictions can result in a low intake of fruits and vegetables and a lack of diversity in the diet. Plant nutrients and plant-based diets could have beneficial effects in patients with CKD: increased fibre intake shifts the gut microbiota towards reduced production of uraemic toxins; plant fats, particularly olive oil, have anti-atherogenic effects; plant anions might mitigate metabolic acidosis and slow CKD progression; and as plant phosphorus has a lower bioavailability than animal phosphorus, plant-based diets might enable better control of hyperphosphataemia. Current evidence suggests that promoting the adoption of plant-based diets has few risks but potential benefits for the primary prevention of CKD, as well as for delaying progression in patients with CKD G3-5. These diets might also help to manage and prevent some of the symptoms and metabolic complications of CKD. We suggest that restriction of plant foods as a strategy to prevent hyperkalaemia or undernutrition should be individualized to avoid depriving patients with CKD of these potential beneficial effects of plant-based diets. However, research is needed to address knowledge gaps, particularly regarding the relevance and extent of diet-induced hyperkalaemia in patients undergoing dialysis.


Assuntos
Dieta Vegetariana , Insuficiência Renal Crônica/dietoterapia , Equilíbrio Ácido-Base , Dieta Saudável , Dieta Mediterrânea , Abordagens Dietéticas para Conter a Hipertensão , Gorduras Insaturadas na Dieta , Fibras na Dieta , Progressão da Doença , Humanos , Hiperpotassemia/etiologia , Fósforo na Dieta , Proteínas de Vegetais Comestíveis , Potássio na Dieta/efeitos adversos , Diálise Renal , Insuficiência Renal Crônica/metabolismo
18.
Emerg Med Pract ; 22(6): 1-24, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32470246

RESUMO

Acid-base disturbances are physiological responses to a wide variety of underlying conditions and critical illnesses. Homeostasis of acid-base physiology is complex and interdependent with the function of the lungs, kidneys, and endogenous buffer systems. Traditionally, these disturbances have been classified in terms of being caused by either a primary respiratory or a metabolic insult and by chronicity and compensation. While existing literature consists largely of physiology reviews, several well-designed studies and clinical practice guidelines provide relevant new perspectives on interpreting and managing acid-base disturbances. This review outlines several approaches to characterizing disturbances, with a case-based format and algorithms to aid in diagnostic testing and interpretation of arterial blood gases.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Diagnóstico Diferencial , Serviço Hospitalar de Emergência/organização & administração , Serviço Hospitalar de Emergência/tendências , Humanos , Corpos Cetônicos/metabolismo , Ácido Láctico/metabolismo
20.
J Int Soc Sports Nutr ; 17(1): 22, 2020 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-32307012

RESUMO

BACKGROUND: The present study investigated the effects of chronic sodium bicarbonate (NaHCO3) ingestion on a single bout of high-intensity exercise and on acid-base balance during 7-day high-altitude exposure. METHODS: Ten recreationally active subjects participated in a pre-test at sea level and a 7-day hiking tour in the Swiss Alps up to 4554 m above sea level. Subjects received either a daily dose of 0.3 g/kg NaHCO3 solution (n = 5) or water as a placebo (n = 5) for 7 days. Anaerobic high-intensity exercise performance was assessed using the portable tethered sprint running (PTSR) test under normoxic and hypoxic conditions (3585 m). PTSR tests assessed overall peak force, mean force, and fatigue index. Blood lactate levels and blood gas parameters were assessed pre- and post-PTSR. Urinary pH and blood gas parameters were further analyzed daily at rest in early morning samples under normoxic and hypoxic conditions. RESULTS: There were no significant differences between the bicarbonate and control group in any of the PTSR-related parameters. However, urinary pH (p = 0.003, ηp2 = 0.458), early morning blood bicarbonate concentration (p < 0.001, ηp2 = 0.457) and base excess (p = 0.002, ηp2 = 0.436) were significantly higher in the bicarbonate group compared with the control group under hypoxic conditions. CONCLUSIONS: These results indicate that oral NaHCO3 ingestion does not ameliorate the hypoxia-induced impairment in anaerobic, high-intensity exercise performance, represented by PTSR-related test parameters, under hypobaric, hypoxic conditions, but the maximal performance measurements may have been negatively affected by other factors, such as poor implementation of PTSR test instructions, pre-acclimatization, the time course of hypoxia-induced renal [HCO3-] compensation, changes in the concentrations of intra- and extracellular ions others than [H+] and [HCO3-], or gastrointestinal disturbances caused by NaHCO3 ingestion. However, chronic NaHCO3 ingestion improves blood bicarbonate concentration and base excess at altitude, which partially represent the blood buffering capacity.


Assuntos
Equilíbrio Ácido-Base/efeitos dos fármacos , Altitude , Limiar Anaeróbio/efeitos dos fármacos , Montanhismo , Bicarbonato de Sódio/administração & dosagem , Adulto , Feminino , Humanos , Masculino , Fenômenos Fisiológicos da Nutrição Esportiva
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