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1.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 33(2): 216-222, 2021 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-33729143

RESUMO

OBJECTIVE: To develop a diagnostic analysis software for determining the type of acid-base balance disorder. METHODS: Mathematical models were built based on Henderson-Hasselbalch equations and compensation formulas, to determine the important parameters of acid-base balance disorder, and to develope acid-base balance disorder analysis process. The software was compiled using the Visual Basic.NET programming language, and the installation package was generated after debugging. Acid-base balance disorder cases were searched by PubMed, Wanfang and CNKI databases from 1980 to 2015, and the blood gas parameters [pH, arterial partial pressure of carbon dioxide (PaCO2), HCO3- and anion gap (AG)] and the types of acid-base imbalance (literature results) were recorded. All cases were reanalyzed by software and the type of acid-base balance disorder was determined (software diagnostic type). Kappa-test and McNemar-test were performed for the two diagnostic results. RESULTS: The "four parameters-four steps" analysis method was used as the analysis process to judge the types of acid-base balance disorder. "Four parameters" included pH, PaCO2, HCO3- and AG. "Four steps" were outlined by following aspects: (1) according to the pH, combined with PaCO2 and HCO3-, the primary types of acid-base balance disorder was determined; (2) according to the compensation situation, double mixed acid-base balance disorder (DABD) was determined; (3) according to AG value, three mixed acid-base disorders (TABD) were determined; (4) the ratio of ΔAG ↑ /ΔHCO3- ↓ was also calculated to determine whether there was normal AG metabolic acidosis or metabolic alkalosis. The software had the characteristics of simple interface, convenient operation, rapid judgment, and comprehensive analysis. It could judge all acid-base balance disorder types excepted "AG normal metabolic acidosis combined metabolic alkalosis". The software was used to reanalyze 112 cases of acid-base balance disorder reported in the literature, with a consistent rate of 87.50% and better consistency of the diagnostic results (Kappa test: κ = 0.84, P < 0.01; McNemar test: χ2 = 0.87, P = 0.65). CONCLUSIONS: The software can be used as an important tool to judge the type of acid-base balance disorder, and provide clinicians with diagnostic reference, which have practical value and application prospect.


Assuntos
Desequilíbrio Ácido-Base , Acidose , Alcalose , Equilíbrio Ácido-Base , Desequilíbrio Ácido-Base/diagnóstico , Humanos , Concentração de Íons de Hidrogênio , Software
2.
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
3.
Rev. esp. anestesiol. reanim ; 67(1): 20-34, ene. 2020. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-197126

RESUMO

Las anomalías en el equilibrio ácido-base son problemas clínicos comunes, y pueden tener efectos perjudiciales en la función celular y ser el indicio de varios trastornos. Por lo tanto, es importante para el clínico, el hacer un diagnóstico preciso de los trastornos ácido-base presentes para un tratamiento adecuado. Se han propuesto 3 enfoques para evaluar los trastornos ácido-base: un enfoque centrado en el bicarbonato, el enfoque de Stewart y el enfoque de exceso de base. Aunque los 2 últimos tienen muchos adeptos, solo discutiremos el enfoque centrado en el bicarbonato. Este enfoque es más fácil de utilizar desde el punto de vista clínico, tiene una evaluación fisiológica del trastorno ácido-base, presenta una lógica fácilmente comprensible para evaluar la gravedad y proporciona, además, una base más sólida para el desarrollo de terapias efectivas. Por lo tanto, nuestro trabajo se limitará a un examen en profundidad de esta teoría. En esta revisión, primero se introducirán nuevos conceptos importantes; sus beneficios y discusión de sus limitaciones; y luego se mostrará su utilización para analizar casos reales. Se ha generado un algoritmo para abordar de forma sistemática el análisis que incorpora estos nuevos conceptos


Abnormalities in the acid-base balance are common clinical problems and can have deleterious effects on cellular function and be a clue to various disorders. Therefore, it is important for the clinician to make a precise diagnosis of the acid-base disorder(s) present for a proper treatment. Three approaches have been proposed to evaluate acid-base disorders: a bicarbonate-centric approach; the Stewart approach, and the base excess approach. Although the latter two have many adherents, we will only discuss the bicarbonate-centric approach. This approach is simpler to utilize at the bedside, has a physiological evaluation of the acid-base disorder, presents an easily understandable approach to assess severity, and provides a more solid foundation for the development of effective therapies. Therefore, the following discussion will be limited to an examination of this approach. In this case-centric review, important new concepts will be introduced first; their benefits and limitations discussed; and then their utilization to analyze actual cases will be shown. A systematic approach algorithm that incorporates these new concepts has been generated and will be highlighted


Assuntos
Humanos , Gasometria , Algoritmos , Desequilíbrio Ácido-Base/diagnóstico , Bicarbonatos/análise , Fenômenos Fisiológicos Celulares , Desequilíbrio Ácido-Base/classificação , Desequilíbrio Ácido-Base/sangue
4.
Am J Physiol Renal Physiol ; 318(2): F363-F374, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31790303

RESUMO

In stone formers (SFs) with idiopathic hypercalciuria, urine pH governs the mineral phase of stones. Calcium phosphate (CaP) SFs have higher urine pH than calcium oxalate (CaOx) SFs. Normal women have higher urine pH than men on fixed diets, accompanied by greater absorption of food alkali. Female CaP and male CaOx SFs have similar urine pH as same sex normal individuals, but male CaP and female CaOx SFs may have abnormal acid-base handling. We studied 25 normal individuals (13 men and 12 women), 17 CaOx SFs (11 men and 6 women), and 15 CaP SFs (8 men and 7 women) on fixed diets. Urine and blood samples were collected under fasting and fed conditions. Female CaOx SFs had lower urine pH and lower alkali absorption, fed, compared with normal women; their urine NH4 was higher and urine citrate excretion lower than in normal women, consistent with their higher net acid excretion. Male CaOx SFs had higher urine citrate excretion and higher serum ultrafilterable citrate levels than normal men. Both male and female CaP SFs had higher urine pH fasting than same sex normal individuals, but only men were higher in the fed period, and there were no differences from normal in gut alkali absorption. CaP SFs of both sexes had higher urine NH4 and lower urine citrate than same sex normal individuals. The lower urine pH of female CaOx SFs seems related to decreased gut alkali absorption, while the higher pH of CaP SFs, accompanied by higher urine NH4 and lower urine citrate, suggests a proximal tubule disorder.


Assuntos
Equilíbrio Ácido-Base , Desequilíbrio Ácido-Base/urina , Oxalato de Cálcio/urina , Fosfatos de Cálcio/urina , Hipercalciúria/urina , Cálculos Renais/urina , Túbulos Renais Proximais/metabolismo , Desequilíbrio Ácido-Base/sangue , Desequilíbrio Ácido-Base/diagnóstico , Desequilíbrio Ácido-Base/fisiopatologia , Adulto , Compostos de Amônio/urina , Biomarcadores/sangue , Biomarcadores/urina , Estudos de Casos e Controles , Ácido Cítrico/urina , Cristalização , Dieta/efeitos adversos , Feminino , Absorção Gastrointestinal , Humanos , Concentração de Íons de Hidrogênio , Hipercalciúria/sangue , Hipercalciúria/diagnóstico , Hipercalciúria/fisiopatologia , Cálculos Renais/sangue , Cálculos Renais/diagnóstico , Cálculos Renais/fisiopatologia , Túbulos Renais Proximais/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores Sexuais , Adulto Jovem
5.
Rev. lab. clín ; 12(4): e66-e74, oct.-dic. 2019.
Artigo em Espanhol | IBECS | ID: ibc-187312

RESUMO

El análisis de gases en sangre es una prueba frecuentemente solicitada en diferentes ámbitos hospitalarios. La medida de los parámetros incluidos en este análisis puede verse afectada por un elevado número de condiciones preanalíticas y es responsabilidad del laboratorio garantizar que los resultados reflejan de forma segura el equilibrio ácido-base y el estado de oxigenación del paciente. Aunque muchas de estas condiciones son comunes al resto de las magnitudes del laboratorio, como la identificación correcta del espécimen, algunas son propias del análisis de gases debido a la estabilidad de las magnitudes incluidas en él. Este documento establece recomendaciones para el control de las condiciones preanalíticas y otras fuentes de error relacionadas con el análisis de gases en sangre, tales como las características de los materiales empleados para la toma de muestra (jeringas, agujas y anticoagulantes), tipo de muestra (sangre arterial, venosa y capilar «arterializada») y las condiciones para el manejo y transporte de la muestra, incluyendo la influencia del tiempo transcurrido entre la extracción y el análisis, la temperatura de la muestra durante el transporte y el transporte en sí


Blood gas analysis is a commonly ordered test in different hospital settings. The measurement of the parameters included in this analysis is vulnerable to a huge number of pre-analytical conditions. Laboratory staff are responsible for ensuring that these results accurately reflect the acid-base and oxygenation status of the patient. Despite many pre-analytical steps in blood gas testing being common to other laboratory tests, such as proper sample identification, others are particular for this determination, such as the stability of the analytes measured. The aim of this document is to provide recommendations for the control of the pre-analytical variables and other error sources related to blood gas analysis. These include the characteristics of the materials used to collect the blood samples (syringes, needles and anticoagulants), the sample types (arterial, venous and «arterialised» capillary blood), as well as the conditions for sample handling and transport, including the effect of the time between sampling and analysis, the temperature during transport, and the type of transport


Assuntos
Humanos , Fase Pré-Analítica/métodos , Desequilíbrio Ácido-Base/diagnóstico , Gasometria/métodos , Equilíbrio Ácido-Base/fisiologia , Guias como Assunto , Ácido Carbônico/análise , Bicarbonatos/análise , Dióxido de Carbono/análise , Oximetria/métodos , Manejo de Espécimes/métodos , Anticoagulantes/uso terapêutico
7.
Med Klin Intensivmed Notfmed ; 114(8): 765-776, 2019 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-31641791

RESUMO

Keeping blood pH levels stable within narrow limits is prerequisite for maintaining normal body function. Disruptions of this equilibrium can occur for a variety of reasons and may result in life-threatening conditions. Therefore, the identification and the interpretation of acid-base disorders are of great importance in emergency medicine. The same applies to intensive care as well as to almost all areas of internal medicine. In this article, we provide a practical overview of all relevant acid-base disorders that are due to both metabolic and respiratory disturbances. In addition, it shows how they can be diagnosed in everyday clinical practice by applying the simplified Stewart Approach.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Desequilíbrio Ácido-Base , Gasometria , Cuidados Críticos/métodos , Desequilíbrio Ácido-Base/sangue , Desequilíbrio Ácido-Base/diagnóstico , Acidose , Humanos
8.
Vnitr Lek ; 65(6): 400-404, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31484480

RESUMO

Traditional diagnostic approach to acute acid-base disorders is based on the assessment of bicarbonate buffer system, in which pH is determined by the ratio of [HCO3-] to pCO2. This, in turn, creates basis for distinguishing metabolic and respiratory disorders, and defines the term “compensation”. The use of electroneutrality advantageously complements the bicarbonate-based approach when dealing with complex acid-base disorders. It is possible to simplify this approach so it can be applied only using mental arithmetics. In principle, the space created by strong ion difference (which can be simplified to [Na+]-[Cl-]) is shared by negative charges on albumin and bicarbonate. In turn, a shrinkage of this space ([Na+]-[Cl-]  36 mM causes alka-losis, as well as a decrease in albumin concentration (for every 10 g/L of albumin, 3 mM is freed to be occupied by [HCO3-]). Lastly, if the sum of negative charges on albumin and [HCO3-] is lower than estimated strong ion difference, an unmeasured anion must be present. This concept is explained on commented case reports.


Assuntos
Desequilíbrio Ácido-Base , Equilíbrio Ácido-Base , Desequilíbrio Ácido-Base/diagnóstico , Bicarbonatos , Humanos , Concentração de Íons de Hidrogênio , Sódio
10.
Semin Nephrol ; 39(4): 328-339, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31300089

RESUMO

Physicochemical models have played an important role in understanding, diagnosing, and treating acid-base disorders for more than 100 years. This review focuses on recent complex models, solved using computers, and shows how these models provide new understanding and diagnostic approaches in acid-base disorders. These advanced models use the following physicochemical principles: (1) chemical equilibrium, (2) conservation of mass, (3) electroneutrality, and (4) osmotic equilibrium to describe the steady-state distribution of H2O and ions in the four major body-fluid spaces, cells, interstitium, plasma, and erythrocytes, and show how this distribution is changed by fluid infusions and losses through renal and gastrointestinal physiological processes. Illustrations of model use with a new comprehensive diagnostic approach are the understanding of an important clinical situation, saline acidosis, and the diagnosis of a patient with diabetic ketoacidosis. This new approach predicts a patient's whole-body base excess and partitions this value into 10 individual values, producing the disorder. These data and other data produced by the diagnostic model described in this review provide much more extensive insight than previous approaches.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Desequilíbrio Ácido-Base/diagnóstico , Desequilíbrio Ácido-Base/fisiopatologia , Modelos Biológicos , Algoritmos , Fenômenos Químicos , Físico-Química , Humanos , Concentração de Íons de Hidrogênio
11.
BMC Nephrol ; 20(1): 194, 2019 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-31146688

RESUMO

BACKGROUND: Acid-base imbalance might promote the progression of chronic kidney disease (CKD), but whether nutrient-derived dietary acid load increases the risk of albuminuria or even high normoalbuminuria is unclear. METHODS: A Japanese cohort comprising 3250 men and 3434 women aged 40-97 years with urine albumin-to-creatinine ratio (ACR) < 33.9 mg/mmol or estimated glomerular filtration rate ≥ 15 ml/min/1.73 m2 were assessed. We performed a cross-sectional evaluation of the association between net endogenous acid production (NEAP), estimated as dietary protein to potassium content ratio, and the presence of high normoalbuminuria (ACR: 1.13-3.38 mg/mmol) or microalbuminuria. RESULTS: Median NEAP was 43.4 (interquartile range (IQR): 34.2-53.4) mEq/day in men and 35.0 (IQR: 27.7-43.6) mEq/day in women. Median ACR was 1.11 (IQR: 0.57-2.49) mg/mmol in men and 1.47 (IQR: 0.82-2.83) mg/mmol in women. In multivariate analysis, the adjusted odds ratio of the highest versus lowest NEAP quartile for microalbuminuria was 1.47 (95% confidence interval (CI): 1.08-1.99) in men and 1.54 (95% CI: 1.11-2.14) in women. For high normoalbuminuria or microalbuminuria, the adjusted odds ratio was 1.28 (95% CI: 1.02-1.59) in men and 1.39 (95% CI: 1.11-1.74) in women. From nutrient composition analysis, subjects with the highest potassium intake, but not protein intake, had lower adjusted odds ratios for the presence of microalbuminuria than those in the lowest quartile for potassium intake. CONCLUSIONS: Higher NEAP was associated with albuminuria and its association might negatively relate to potassium intake in an adult Japanese population.


Assuntos
Desequilíbrio Ácido-Base/epidemiologia , Albuminúria/epidemiologia , Proteínas na Dieta/administração & dosagem , Potássio na Dieta/administração & dosagem , Insuficiência Renal Crônica/epidemiologia , Desequilíbrio Ácido-Base/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Albuminúria/diagnóstico , Estudos de Coortes , Estudos Transversais , Dieta/efeitos adversos , Dieta/tendências , Proteínas na Dieta/efeitos adversos , Feminino , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Potássio na Dieta/efeitos adversos , Insuficiência Renal Crônica/diagnóstico
12.
Crit Rev Clin Lab Sci ; 56(3): 147-169, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30917291

RESUMO

Acid-base homeostasis is fundamental for life. The body is exceptionally sensitive to changes in pH, and as a result, potent mechanisms exist to regulate the body's acid-base balance to maintain it in a very narrow range. Accurate and timely interpretation of an acid-base disorder can be lifesaving but establishing a correct diagnosis may be challenging. The underlying cause of the acid-base disorder is generally responsible for a patient's signs and symptoms, but laboratory results and their integration into the clinical picture is crucial. Important acid-base parameters are often available within minutes in the acute hospital care setting, and with basic knowledge it should be easy to establish the diagnosis with a stepwise approach. Unfortunately, many caveats exist, beginning in the pre-analytical phase. In the post-analytical phase, studies on the arterial reference pH are scarce and therefore many different reference values are used in the literature without any solid evidence. The prediction models that are currently used to assess the acid-base status are approximations that are mostly based on older studies with several limitations. The two most commonly used methods are the physiological method and the base excess method, both easy to use. The secondary response equations in the base excess method are the most convenient. Evaluation of acid-base disorders should always include the assessment of electrolytes and the anion gap. A major limitation of the current acid-base laboratory tests available is the lack of rapid point-of-care laboratory tests to diagnose intoxications with toxic alcohols. These intoxications can be fatal if not recognized and treated within minutes to hours. The surrogate use of the osmolal gap is often an inadequate substitute in this respect. This article reviews the role of the clinical laboratory to evaluate acid-base disorders.


Assuntos
Desequilíbrio Ácido-Base , Análise Química do Sangue , Equilíbrio Ácido-Base , Desequilíbrio Ácido-Base/sangue , Desequilíbrio Ácido-Base/diagnóstico , Desequilíbrio Ácido-Base/fisiopatologia , Desequilíbrio Ácido-Base/urina , Adulto , Idoso , Eletrólitos/sangue , Feminino , Humanos , Concentração de Íons de Hidrogênio , Masculino , Pessoa de Meia-Idade , Adulto Jovem
13.
Am J Nurs ; 119(3): 52-56, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30801317

RESUMO

Arterial blood gas (ABG) analysis assesses the adequacy of ventilation, oxygenation, and the acid-base status of the body by measuring the levels of pH, oxygen, carbon dioxide, and bicarbonate in arterial blood. Interpretation of ABG results, which can play a major role in diagnosis and treatment of patients with pulmonary and other critical conditions, can sometimes be difficult. This article focuses on basic ABG analysis and interpretation, discusses the combinations of imbalances that may occur, and reviews the compensatory mechanisms that arise as a result.


Assuntos
Desequilíbrio Ácido-Base/diagnóstico , Desequilíbrio Ácido-Base/metabolismo , Gasometria , Dióxido de Carbono/sangue , Oxigênio/sangue , Humanos
14.
Tunis Med ; 97(12): 1357-1361, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32173805

RESUMO

BACKGROUND: Trauma is a leading cause of death in young people and hemorrhagic shock is a leading mechanism of this mortality. Hypoperfusion can be difficult to diagnose clinically, especially in younger patients. Arterial Base Excess (BE) has been used as an early indicator of hypoperfusion. AIM: To evaluate the prognostic value of admission BE in severe trauma patients admitted to the emergency department (ED). METHODS: In this prospective study, severe trauma patients meeting high velocity criteria admitted to the ED during the study period were included. BE was calculated from arterial blood gas samples. Multivariate analysis was performed for Day-1 and Day-7 post trauma mortality. ROC characteristics and survival curves were used. RESULTS: We included 479 patients. Median age was 37 (18-90). Eighty-one per cent were male. Clinical characteristics n(%): GCS<13: 170(35); SBP<90 mmHg: 64(13) and SpO2 <90%: 82(17). Mean ISS was 22 ± 13. Mortality was at days 1 and 7: 2.2% and 27.3%, respectively. Median BE was -3.2 mmol/l (-25; 28). Forty-five per cent had a BE ≤ -3.5 mmol/l. In multivariate analysis, initial BE ≤ -6.5 mmol/l was predictive of first day mortality with an Odds Ratio; [CI95%] = 3.17; [1.4-7.1]; p=0.005. Similar results were found at Day 7: Odds Ratio; [CI95%] = 1.5; [1.14-1.96]; p=0.003. BE showed high prognostic value for both mortality rates. Survival curve was significant for BE> -6.5mmol/l. CONCLUSION: in this study, a high BE above 6.5mmol/L showed a significant prognostic value in immediate and early mortality and is proposed as a marker of injury severity in trauma patients admitted to the ED. Prediction was better for the immediate mortality and thus could be proposed as a triage tool in the ED.


Assuntos
Desequilíbrio Ácido-Base/diagnóstico , Serviço Hospitalar de Emergência , Mortalidade Hospitalar , Índices de Gravidade do Trauma , Ferimentos e Lesões/diagnóstico , Ferimentos e Lesões/mortalidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Gasometria/métodos , Gasometria/normas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mortalidade , Admissão do Paciente , Índice de Perfusão/métodos , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Triagem/métodos , Ferimentos e Lesões/metabolismo , Adulto Jovem
15.
J Investig Med ; 67(4): 750-760, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30530786

RESUMO

Electrolyte and acid-base disorders are commonly seen in critically ill and other hospitalized patients. A scoring system is needed to assess the severity of electrolyte and acid-base disorders and to predict outcome in hospital patients. Herein, we prospectively enrolled a total of 322,046 patients, including 84,700 patients in the derivation cohort and 237,346 in the validation cohort, in a large, tertiary hospital in East China from 2014 to 2017. A points-scoring system of general electrolyte and acid-base disorders with a sum of 20.8 points was generated by multiple logistic regression analysis of the derivation cohort. Receiver operating characteristic curve analysis showed that the optimal cut-off value of 2.0 was associated with 65.4% sensitivity and 88.4% specificity (area under the curve: 0.818 (95% CI 0.809 to 0.827)) to predict hospital mortality in the validation cohort. On Kaplan-Meier survival analysis, the five intervals of risk score (Q1: 0 to 2.0; Q2: 2.1 to 2.5; Q3: 2.6 to 3.3; Q4: 3.4 to 4.5; and Q5: >4.5 points) showed differences in hospital survival (p<0.001). Elevated (delta) risk score >2 during hospitalization increased the risk of hospital death, while those with a delta risk score <0 and <-2 points had higher survival rates. This novel scoring system could be used to evaluate and to dynamically monitor the severity of electrolyte and acid-base disorders in hospitalized patients.


Assuntos
Desequilíbrio Ácido-Base/diagnóstico , Eletrólitos/metabolismo , Hospitalização , Desequilíbrio Ácido-Base/mortalidade , Idoso , Estudos de Coortes , Feminino , Mortalidade Hospitalar , Humanos , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prevalência , Modelos de Riscos Proporcionais , Reprodutibilidade dos Testes , Fatores de Risco , Resultado do Tratamento
17.
Theor Biol Med Model ; 15(1): 14, 2018 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-30196793

RESUMO

BACKGROUND: The acidity of human body fluids, expressed by the pH, is physiologically regulated in a narrow range, which is required for the proper function of cellular metabolism. Acid-base disorders are common especially in intensive care, and the acid-base status is one of the vital clinical signs for the patient management. Because acid-base balance is connected to many bodily processes and regulations, complex mathematical models are needed to get insight into the mixed disorders and to act accordingly. The goal of this study is to develop a full-blood acid-base model, designed to be further integrated into more complex human physiology models. RESULTS: We have developed computationally simple and robust full-blood model, yet thorough enough to cover most of the common pathologies. Thanks to its simplicity and usage of Modelica language, it is suitable to be embedded within more elaborate systems. We achieved the simplification by a combination of behavioral Siggaard-Andersen's traditional approach for erythrocyte modeling and the mechanistic Stewart's physicochemical approach for plasma modeling. The resulting model is capable of providing variations in arterial pCO2, base excess, strong ion difference, hematocrit, plasma protein, phosphates and hemodilution/hemoconcentration, but insensitive to DPG and CO concentrations. CONCLUSIONS: This study presents a straightforward unification of Siggaard-Andersen's and Stewart's acid-base models. The resulting full-blood acid-base model is designed to be a core part of a complex dynamic whole-body acid-base and gas transfer model.


Assuntos
Equilíbrio Ácido-Base , Desequilíbrio Ácido-Base/epidemiologia , Modelos Biológicos , Modelos Químicos , Modelos Teóricos , Equilíbrio Ácido-Base/fisiologia , Desequilíbrio Ácido-Base/diagnóstico , Desequilíbrio Ácido-Base/fisiopatologia , Humanos , Concentração de Íons de Hidrogênio
18.
Am J Nephrol ; 48(1): 15-20, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29990967

RESUMO

The initial assessment of acid-base status is usually based on the measurement of total CO2 concentration ([TCO2]) in venous blood, a surrogate for [HCO3-]. Previously, we posited that the reference limits of serum [TCO2] in current use are too wide. Based on studies on the acid-base composition of normal subjects, we suggested that the reference limits of serum [TCO2] at sea level be set at 23-30 mEq/L. To validate this proposal, we queried the University of California at Los Angeles (UCLA's) Integrated Clinical and Research Data Repository, a database containing information on 4.5 million patients seen at UCLA from 2006 to the present. Criteria for inclusion included adults (18-40 years of age), who were free of disorders that could affect acid-base balance, were not taking medications that could affect acid-base balance, and were seen for a routine medical examination or immunization in the outpatient setting. The number of individuals who met the inclusion criteria (52% female and 48% male) was 28,480, with a mean age of 28.9 ± 5.1 years. The mean serum [TCO2] level was slightly higher in males than females, 26.6 ± 2.16 mEq/L vs. 25.0 ± 2.11 mEq/L (p < 0.05). Ninety-one percent of patient values were within the proposed 23-30 mEq/L range and 61.7% were within the 24-27 mEq/L range. These findings validate our proposal that the reference range of serum [TCO2] in venous blood at sea level be narrowed to 23-30 mEq/L. Subjects with serum [TCO2] outside this range might require assessment with a venous blood gas to exclude the presence of clinically important acid-base disorders.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Desequilíbrio Ácido-Base/diagnóstico , Dióxido de Carbono/sangue , Desequilíbrio Ácido-Base/sangue , Adolescente , Adulto , Bicarbonatos/sangue , Gasometria/métodos , Bases de Dados Factuais/estatística & dados numéricos , Feminino , Humanos , Masculino , Valores de Referência , Fatores Sexuais , Veias , Adulto Jovem
19.
J Anesth ; 32(4): 499-505, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29725827

RESUMO

PURPOSE: To suggest a simplified method for strong ion gap ([SIG]) calculation. PATIENTS AND METHODS: To simplify [SIG] calculation, we used the following assumptions: (1) the major determinants of apparent strong ion difference ([SIDa]) are [Na+], [K+] and [Cl-] (2) [Ca2+] and [Mg2+] do not contribute significantly to [SIDa] variation and can be replaced by their reference concentrations (3) physiologically relevant pH variation is at the order of 10-2 and therefore we can assume a standard value of 7.4. In the new model, [SIDa] is replaced by its adjusted form, i.e. [SIDa,adj] = [Na+] + [K+] - [Cl-] + 6.5 and [SIG] is replaced by "bicarbonate gap", i.e. [BICgap] = [SIDa,adj] - (0.25·[Albumin]) - (2·[Phosphate]) - [HCO3-]. The model was tested in 224 postoperative cardiac surgical patients. RESULTS: Strong correlations were observed between [SIDa,adj] and [SIDa] (r = 0.93, p < 0.0001) and between [BICgap] and [SIG] (r = 0.95, p < 0.0001). The mean bias (limits of agreement) of [SIDa,adj] - [SIDa] and of [BICgap]-[SIG] was - 0.6 meq/l (- 2.7 to 1.5) and 0.2 meq/l (- 2 to 2.4), respectively. The intraclass correlation coefficients between [SIDa,adj] and [SIDa] and between [BICgap] and [SIG] were 0.90 and 0.95, respectively. The sensitivities and specificities for the prediction of a [lactate-] > 4 meq/l were 73.4 and 82.3% for a [BICgap] > 12.2 meq/l and 74.5 and 83.1% for a [SIG] > 12 meq/l, respectively. CONCLUSIONS: The [BICgap] model bears a very good agreement with the [SIG] model while being simpler and easier to apply at the bedside. [BICgap] could be used as an alternative tool for the diagnosis of unmeasured ion acidosis.


Assuntos
Equilíbrio Ácido-Base , Desequilíbrio Ácido-Base/diagnóstico , Procedimentos Cirúrgicos Cardíacos/métodos , Acidose/diagnóstico , Idoso , Feminino , Humanos , Íons , Ácido Láctico/sangue , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Sódio/sangue
20.
Nephron ; 139(4): 293-298, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29649820

RESUMO

BACKGROUND: Acid-base disturbances are frequent in critically ill patients. Arterial blood gas (ABG) is the gold standard in the diagnosis of these disturbances, but it is invasive with potential hazards. For patients with a central venous catheter, venous blood gas (VBG) sampling may be an alternative, less-invasive diagnostic tool. However, the accuracy of a central VBG-based acid-base disorder diagnosis compared to an ABG is unknown. The primary objective of this study was to assess the accuracy of a central VBG-based acid-base disorder diagnosis compared to the "gold standard" ABG in critically ill patients. METHODS: This was a study of adult patients in a medical intensive care unit that had simultaneously drawn ABG and central VBG samples. Expert acid-base diagnosticians, all nephrologists, diagnosed the acid-base disorder(s) in each blood gas sample. The central VBG diagnostic accuracy was assessed with percent agreement, sensitivity, and specificity compared to the ABG-based diagnosis. RESULTS: The study involved 23 participants. Overall, the central VBG had 100% sensitivity for metabolic acidosis, metabolic alkalosis, and respiratory acidosis, and lower sensitivity (71%) for respiratory alkalosis, and high percent agreement, ranging from 75 to 94%. VBG-based diagnoses in vasopressor-dependent patients (n = 13, 56.5%) performed similarly to the entire sample. CONCLUSIONS: In critically ill adult patients, central VBG may be used to detect and diagnose acid-base disturbances with reasonable diagnostic accuracy, even in shock states, compared to the ABG. This study supports the use of central VBG for diagnosis of acid-base disturbances in critically ill patients.


Assuntos
Equilíbrio Ácido-Base , Desequilíbrio Ácido-Base/diagnóstico , Gasometria/métodos , Cuidados Críticos/métodos , Desequilíbrio Ácido-Base/sangue , Acidose/diagnóstico , Adulto , Idoso , Alcalose/diagnóstico , Cateterismo Venoso Central , Estado Terminal , Estudos Transversais , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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