RESUMO
INTRODUCTION: In newborns with the diagnosis of hypoxic-ischemic encephalopathy (HIE) treated with hypother mia, metabolic alterations are observed, which are associated with neurological prognosis. Hypo magnesemia has been reported frequently in the literature in these patients, but it is not measured or corrected in all neonatal healthcare centers. OBJECTIVE: To evaluate the frequency of hypomag nesemia and hypocalcemia in newborns with HIE treated with whole-body hypothermia and to evaluate the response to the magnesium sulfate administration. PATIENTS AND METHOD: Prospective, observational and descriptive study in hospitalized newborns with the diagnosis of HIE and trea ted with whole-body hypothermia between the years 2016 and 2017. Serial blood measurement of magnesemia (Mg) and calcemia (Ca) was performed. When presenting an Mg level < 1.8 mg/dl, supplementation with magnesium sulfate was administered to maintain levels between 1.9 and 2.8 mg/dl. The frecuency of hypomagnesemia, hypocalcemia and clinical evolution was registered. A descriptive statistical analysis was performed, with central tendency measures. RESULTS: Sixteen ca ses were included, 13 of them presented hypomagnesemia (81.3%), with early-onset (6-36 hours of life), which was normalized with magnesium sulfate treatment, receiving a second dose 4 patients. Six of 16 patients presented hypocalcemia (37.5 %). CONCLUSIONS: Hypomagnesemia is frequent (80%), similar to that described in the literature, and should be controlled and corrected early, given its physiological role, in the same way that calcium is controlled.
Assuntos
Hipocalcemia/etiologia , Hipotermia Induzida , Hipóxia-Isquemia Encefálica/complicações , Hipóxia-Isquemia Encefálica/terapia , Deficiência de Magnésio/etiologia , Biomarcadores/sangue , Feminino , Humanos , Hipocalcemia/diagnóstico , Hipocalcemia/tratamento farmacológico , Hipocalcemia/epidemiologia , Recém-Nascido , Magnésio/sangue , Deficiência de Magnésio/diagnóstico , Deficiência de Magnésio/tratamento farmacológico , Deficiência de Magnésio/epidemiologia , Sulfato de Magnésio/uso terapêutico , Masculino , Estudos Prospectivos , Fatores de Risco , Resultado do TratamentoRESUMO
Resumen: Introducción: En recién nacidos (RN) con encefalopatía hipóxico isquémica (EHI) en hipotermia se describen alte raciones metabólicas que se asocian a pronóstico neurológico. La hipomagnesemia ha sido reportada en la literatura, pero no es medida ni corregida en todos los centros de atención neonatal. Objeti vo: Evaluar la frecuencia de hipomagnesemia e hipocalcemia en RN con EHI en tratamiento con hipotermia corporal total y evaluar la respuesta al aporte de sulfato de magnesio. Pacientes y Méto do: Estudio prospectivo, observational y descriptivo en RN con EHI sometidos a hipotermia corporal total, hospitalizados entre los años 2016-2017. Se realizó medición seriada en sangre de magnesemia (Mg) y calcemia (Ca). Con Mg menor o igual de 1,8 mg/dl se administró suplemento como sulfato de Mg para mantener niveles entre 1,9 y 2,8 mg/dl. Se describió la frecuencia de hipomagnesemia e hipocalcemia y su presentación en el tiempo. Se realizó registro prospectivo de evolución clínica. Se hizo un análisis estadístico descriptivo, con medidas de tendencia central. Resultados: Se incluyeron 16 pacientes. Presentaron hipomagnesemia 13/16 (81,3%), la que fue precoz (6-36 h de vida), nor malizándose con aporte de sulfato de magnesio, requiriendo 2a dosis 4 de ellos. Presentaron hipo- calcemia 6/16 (37,5%). Conclusiones: La hipomagnesemia es frecuente (80%), similar a lo descrito en la literatura. Dado su importancia fisiológica debe controlarse y corregirse, de igual manera que el calcio.
Abstract: Introduction: In newborns with the diagnosis of hypoxic-ischemic encephalopathy (HIE) treated with hypother mia, metabolic alterations are observed, which are associated with neurological prognosis. Hypo magnesemia has been reported frequently in the literature in these patients, but it is not measured or corrected in all neonatal healthcare centers. Objective: To evaluate the frequency of hypomag nesemia and hypocalcemia in newborns with HIE treated with whole-body hypothermia and to evaluate the response to the magnesium sulfate administration. Patients and Method: Prospective, observational and descriptive study in hospitalized newborns with the diagnosis of HIE and trea ted with whole-body hypothermia between the years 2016 and 2017. Serial blood measurement of magnesemia (Mg) and calcemia (Ca) was performed. When presenting an Mg level < 1.8 mg/dl, supplementation with magnesium sulfate was administered to maintain levels between 1.9 and 2.8 mg/dl. The frecuency of hypomagnesemia, hypocalcemia and clinical evolution was registered. A descriptive statistical analysis was performed, with central tendency measures. Results: Sixteen ca ses were included, 13 of them presented hypomagnesemia (81.3%), with early-onset (6-36 hours of life), which was normalized with magnesium sulfate treatment, receiving a second dose 4 patients. Six of 16 patients presented hypocalcemia (37.5 %). Conclusions: Hypomagnesemia is frequent (80%), similar to that described in the literature, and should be controlled and corrected early, given its physiological role, in the same way that calcium is controlled.
Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Hipóxia-Isquemia Encefálica/complicações , Hipóxia-Isquemia Encefálica/terapia , Hipocalcemia/etiologia , Hipotermia Induzida , Deficiência de Magnésio/etiologia , Biomarcadores/sangue , Estudos Prospectivos , Fatores de Risco , Resultado do Tratamento , Hipocalcemia/diagnóstico , Hipocalcemia/tratamento farmacológico , Hipocalcemia/epidemiologia , Magnésio/sangue , Deficiência de Magnésio/diagnóstico , Deficiência de Magnésio/tratamento farmacológico , Deficiência de Magnésio/epidemiologia , Sulfato de Magnésio/uso terapêuticoRESUMO
OBJECTIVE: The aim of this study was to evaluate the association of serum magnesium levels with proton pump inhibitors (PPIs) use and other factors. METHODS: This was a cross-sectional study of 151 patients admitted with acute diseases in the Internal Medicine Division of the Hospital de Clinicas de Porto Alegre, after the exclusion of conditions that are commonly associated with hypomagnesemia: diarrhea; vomiting; chronic alcohol use; severely uncompensated diabetes mellitus; and chronic use of laxatives, diuretics or other drugs causing magnesium deficiency. RESULTS: All patients had normal serum magnesium levels. Serum albumin and creatinine levels were positively associated with serum magnesium levels, after adjusting for confounders. There was no difference between mean serum magnesium levels of PPI users and non-users, nor between men and women; there was also no correlation among age, serum phosphorus, and potassium levels with serum magnesium levels. Limitations of this study include the absence of an instrument for measuring adherence to PPI use and the sample size. CONCLUSION: The association of PPI use and hypomagnesemia is uncommon. Congenital defects in the metabolism of magnesium may be responsible for hypomagnesemia in some patients using this drug class.
OBJETIVO: O objetivo desse estudo foi verificar a associação do nível sérico do magnésio com o uso de inibidores de bomba de prótons (IBP) e outros fatores. MÉTODOS: Realizou-se estudo transversal com 151 pacientes admitidos com doenças agudas no serviço de medicina interna do Hospital de Clínicas de Porto Alegre. Foram excluídos aqueles pacientes com condições usualmente relacionadas à hipomagnesemia: diarréia; vômitos; diabéticos agudamente descompensados; uso crônico de laxantes, álcool, diuréticos ou outros fármacos relacionados. RESULTADOS: Todos os pacientes apresentaram níveis normais de magnésio. Albumina e creatinina sérica se associaram positivamente com os níveis de magnésio sérico, após ajuste para fatores confundidores. Não houve diferença no nível sérico de magnésio em usuários ou não-usuários de IBP ou entre homens e mulheres. Não houve correlação com idade, nível sérico de fósforo e potássio. As principais limitações desse estudo foram a ausência de instrumento para medir a adesão aos IBPs e o tamanho da amostra. CONCLUSÃO: A associação do uso de IBP e hipomagnesemia é rara. Defeitos congênitos no metabolismo do magnésio devem ser responsáveis pelo surgimento de hipomagnesemia em usuários de dessa classe de fármacos.
Assuntos
Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Deficiência de Magnésio/induzido quimicamente , Deficiência de Magnésio/epidemiologia , Magnésio/sangue , Inibidores da Bomba de Prótons/efeitos adversos , Creatinina/sangue , Métodos Epidemiológicos , Deficiência de Magnésio/sangue , Deficiência de Magnésio/diagnóstico , Albumina Sérica/análiseRESUMO
OBJECTIVE: The aim of this study was to evaluate the association of serum magnesium levels with proton pump inhibitors (PPIs) use and other factors. METHODS: This was a cross-sectional study of 151 patients admitted with acute diseases in the Internal Medicine Division of the Hospital de Clinicas de Porto Alegre, after the exclusion of conditions that are commonly associated with hypomagnesemia: diarrhea; vomiting; chronic alcohol use; severely uncompensated diabetes mellitus; and chronic use of laxatives, diuretics or other drugs causing magnesium deficiency. RESULTS: All patients had normal serum magnesium levels. Serum albumin and creatinine levels were positively associated with serum magnesium levels, after adjusting for confounders. There was no difference between mean serum magnesium levels of PPI users and non-users, nor between men and women; there was also no correlation among age, serum phosphorus, and potassium levels with serum magnesium levels. Limitations of this study include the absence of an instrument for measuring adherence to PPI use and the sample size. CONCLUSION: The association of PPI use and hypomagnesemia is uncommon. Congenital defects in the metabolism of magnesium may be responsible for hypomagnesemia in some patients using this drug class.
Assuntos
Deficiência de Magnésio/induzido quimicamente , Deficiência de Magnésio/epidemiologia , Magnésio/sangue , Inibidores da Bomba de Prótons/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Creatinina/sangue , Métodos Epidemiológicos , Feminino , Humanos , Deficiência de Magnésio/sangue , Deficiência de Magnésio/diagnóstico , Masculino , Pessoa de Meia-Idade , Albumina Sérica/análise , Adulto JovemRESUMO
BACKGROUND: The aim of this study was to evaluate the role of hypomagnesemia as a risk factor for the development of acute kidney injury (AKI) and non-recovery of renal function in critically ill patients. METHODS: A cohort study was conducted by collecting data from March to June 2011 in 232 patients who were admitted into an intensive care unit (ICU). Magnesium serum levels were measured daily during ICU stay. Hypomagnesemia was defined as an episode of serum magnesium concentration of <0.70 mmol/L during ICU stay. The Risk, Injury, Failure, Loss and End-stage kidney disease (RIFLE) criteria were used to define AKI. Renal function recovery was defined as an absence of AKI by the RIFLE criteria over a 48-h period, or at ICU discharge, in the patients who developed AKI during ICU stay. RESULTS: The presence of hypomagnesemia was similar in patients with or without AKI (47 and 62%, respectively, P = 0.36). The presence of hypomagnesemia was higher in patients who did not recover renal function when compared with patients who recovered renal function (70 versus 31%, P = 0.003). A multivariate analysis identified hypomagnesemia as an independent risk factor for non-recovery of renal function (P = 0.005). Patients with and without hypomagnesemia had similar mortality rates (P = 0.63). CONCLUSIONS: Hypomagnesemia was an independent risk factor for non-recovery of renal function in a cohort of critically ill AKI patients.
Assuntos
Injúria Renal Aguda/etiologia , Estado Terminal/mortalidade , Mortalidade Hospitalar , Unidades de Terapia Intensiva , Rim/fisiopatologia , Deficiência de Magnésio/complicações , Magnésio/sangue , Injúria Renal Aguda/mortalidade , Feminino , Seguimentos , Hospitalização , Humanos , Testes de Função Renal , Deficiência de Magnésio/diagnóstico , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Fatores de Risco , Taxa de SobrevidaRESUMO
A retrospective chart review of the case notes of all children aged 6 months to 8 years presenting with fever and seizures to the University Hospital of the West Indies (UHWI) between January 2000 and December 2004 was conducted. Descriptive analyses were performed. Fifty-nine children (median age 1.58 years, range 0.58 to 6.83 years) were entered into the study. The main laboratory abnormalities were metabolic acidosis (23%), anaemia (10%), leukocytosis (35%) and hypomagnesaemia (3%). These were not significantly associated with meningitis or an underlying bacterial infection. There were no significant episodes of hyponatraemia, hypocalcaemia or hypoglycaemia. Meningitis was uncommon and occurred in only two (3.4%) children both younger than 16 months of age and who had other abnormal clinical signs. This study demonstrated that routine performance of haematological and biochemical investigations in children presenting with seizures and fever were of limited value. Lumbar punctures in children older than age 18 months with no other abnormal clinical signs were also found to be of low yield. Current American Academy of Paediatrics (AAP) recommendations that serum electrolytes, calcium, phosphate, magnesium, complete blood count and blood glucose should not be performed routinely in a child with a first simple febrile seizure can be safely applied to this study population.
Se llevó a cabo un estudio retrospectivo de las historias clínicas en busca de notas sobre los casos de todos los niños de 6 meses a 8 años de edad que se presentaron con fiebre y convulsiones en el Hospital Universitario de West Indies (HUWI) entre enero de 2000 y diciembre de 2004. Se realizaron análisis descriptivos. Cincuenta y nueve niños (edad mediana (1.58 años, rango 0.58 a 6.83 años) formaron parte de este estudio. Las principales anormalidades halladas mediante el laboratorio fueron: acidosis metabólica (23%), anemia (10%), leucocitosis (35%), e hipomagnesemia (3%). Éstas no estuvieron significativamente asociadas con meningitis o alguna infección bacteriana subyacente. No hubo episodios significativos de hiponatremia, hipocalcemia o hipoglicemia. La meningitis fue poco común, ocurriendo sólo en dos niños (3.4%), ambos con menos de 16 meses de edad y con otros signos clínicos anormales. Este estudio demostró que el trabajo de rutina realizado en las investigaciones hematológicas y bioquímicas en los niños que se presentaron con fiebre y convulsiones, tuvo un valor limitado. También se halló que las punciones lumbares realizadas a niños de más de 18 meses sin ningún otro signo clínico anormal, tuvieron poco valor. Las recomendaciones actuales de la Academia Americana de Pediatría (AAP) en cuanto a que las pruebas de electrolitos en suero, las mediciones de calcio, fosfato, magnesio, el conteo sanguíneo completo, y la prueba de glucosa en sangre, no deben ser realizadas rutinariamente en un niño con una primera simple convulsión febril, pueden ser aplicadas con seguridad a esta población bajo estudio.
Assuntos
Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Acidose/diagnóstico , Anemia/diagnóstico , Febre/diagnóstico , Leucocitose/diagnóstico , Deficiência de Magnésio/diagnóstico , Convulsões/diagnóstico , Acidose/complicações , Anemia/complicações , Testes de Química Clínica , Diagnóstico Diferencial , Febre/etiologia , Testes Hematológicos , Leucocitose/complicações , Deficiência de Magnésio/complicações , Meningite , Fatores de Risco , Convulsões/etiologia , Índias OcidentaisRESUMO
A retrospective chart review of the case notes of all children aged 6 months to 8 years presenting with fever and seizures to the University Hospital of the West Indies (UHWI) between January 2000 and December 2004 was conducted. Descriptive analyses were performed. Fifty-nine children (median age 1.58 years, range 0.58 to 6.83 years) were entered into the study. The main laboratory abnormalities were metabolic acidosis (23%), anaemia (10%), leukocytosis (35%) and hypomagnesaemia (3%). These were not significantly associated with meningitis or an underlying bacterial infection. There were no significant episodes of hyponatraemia, hypocalcaemia or hypoglycaemia. Meningitis was uncommon and occurred in only two (3.4%) children both younger than 16 months of age and who had other abnormal clinical signs. This study demonstrated that routine performance of haematological and biochemical investigations in children presenting with seizures and fever were of limited value. Lumbar punctures in children older than age 18 months with no other abnormal clinical signs were also found to be of low yield Current American Academy of Paediatrics (AAP) recommendations that serum electrolytes, calcium, phosphate, magnesium, complete blood count and blood glucose should not be performed routinely in a child with a first simple febrile seizure can be safely applied to this study population.
Assuntos
Acidose/diagnóstico , Anemia/diagnóstico , Febre/diagnóstico , Leucocitose/diagnóstico , Deficiência de Magnésio/diagnóstico , Convulsões/diagnóstico , Acidose/complicações , Anemia/complicações , Criança , Pré-Escolar , Testes de Química Clínica , Diagnóstico Diferencial , Feminino , Febre/etiologia , Testes Hematológicos , Humanos , Lactente , Leucocitose/complicações , Deficiência de Magnésio/complicações , Masculino , Meningite , Fatores de Risco , Convulsões/etiologia , Índias OcidentaisRESUMO
Bartter's syndrome is a disorder that has been linked to mutations in one of three ion transporter proteins: NKCC2 (type I), ROMK (type II) and CCLNKB (type III), which affects a final common pathway that participates in ion transport by thick ascending limb cells. We present an atypical case of mitochondriopathy combined with tubule functional disturbances compatible with Bartter's syndrome and definitive sensorineural blindness. Our patient had a peculiar clinical presentation with signs of salt and volume depletion, low blood pressure and secondary hyperaldosteronism, associated with hypokalemic metabolic alkalosis, hypocalcemia and severe hypomagnesemia, uncommon in genetic forms of Bartter's syndrome. The enhanced absolute and fractional sodium excretion in our patient compared to volunteers was accompanied by increased post-proximal sodium rejection, suggesting a striking ion transport dysfunction in these nephron segments. These findings lead to the Bartter's syndrome diagnosis, accompanied by a suppose mitochondrial tick ascending loop of Henle epithelium dysfunction that may reflect the high energy supplied by mitochondria electron transport chain, required for this nephron segment to maintain normal ion transport.
Assuntos
Síndrome de Bartter/diagnóstico , Cegueira/diagnóstico , Nefropatias/diagnóstico , Sódio/metabolismo , Alcalose/complicações , Alcalose/diagnóstico , Síndrome de Bartter/complicações , Cegueira/complicações , Feminino , Humanos , Hipocalcemia/complicações , Hipocalcemia/diagnóstico , Hipopotassemia/complicações , Hipopotassemia/diagnóstico , Nefropatias/complicações , Testes de Função Renal , Alça do Néfron/patologia , Deficiência de Magnésio/complicações , Deficiência de Magnésio/diagnóstico , Pessoa de Meia-Idade , Mitocôndrias/patologia , Prognóstico , Medição de Risco , Síndrome , UrináliseRESUMO
Avaliar conhecimentos sobre a hipomagnesemia dos preceptores da Residência da Clínica Médica do Hospital Regional de Säo José, Säo José, SC. Aplicaçäo de questionário por escrito, durante uma reuniäo preparatória da Residência, para 18 clínicos do serviço. Todos os questionários foram recolhidos ao final da reuniäo. Doze (66,67 por cento) dos 18 participantes responderam, sendo sete mulheres (58,33 por cento). Anos de formado: 4 a 25 anos (média e mediana de 11,25). Eram de nove especialidades distintas, 10 (83,33 por cento) completaram residência médica e dois (16,67 por cento) mestrado. cinco (41,67 por cento) trabalhavam na emergência e cinco na UTI. A freqüência estimada da hipomagnesemia era <25 por cento para nove (75 por cento) respondentes. Das causas, o diurético foi citado por sete (58,33 por cento) e o álcool três (25 por cento). Os sintomas mais lembrados foram arritmia - sete (58,33 por cento), convulsäo e alteraçäo de consciência - quatro (33,33 por cento) cada. Sete (58,33 por cento) consideravam a hipomagnesemia uma emergência. Sete (58,33 por cento) solicitavam rotineiramente a dosagem. Outros exames laboratoriais necessários para avaliaçäo inicial: creatinina citada por oito (66,67 por cento), glicemia sete (58,33 por cento), hemograma e potássio: cinco (41,67 por cento), sódio e parcial de urina: três (25 por cento). Nenhum respondente sabia o valor correto da dosagem de Mg. Os respondentes possuíam os conhecimentos adequados e refletiam as diferenças existentes na literatura médica. Isso permitiu as variaçöes clínicas em diagnóstico e terapêutica. Assim, mais que a metade considerava hipomagnesemia como emergência e a mesma quantidade solicitava rotineiramente a dosagem do Mg independente da sintomatologia. E nenhum sabia o custo real do exame.
Assuntos
Competência Clínica , Padrões de Prática Médica , Deficiência de Magnésio/complicações , Deficiência de Magnésio/diagnóstico , Deficiência de Magnésio/terapia , Magnésio/administração & dosagem , Magnésio/farmacologia , Magnésio/uso terapêutico , Medicina Baseada em EvidênciasRESUMO
OBJECTIVES: Neonatal hypomagnesemia is defined as total magnesium (TMg) < or = 0.65 mmol/L (1.6 mg/dl). However, magnesium (Mg) deficiency and sufficiency overlap at serum values of 0.57 to 0.74 mmol/L (1.4 to 1.8 mg/dl). We hypothesized that (1) some infants with TMg < or = 0.65 mmol/L (1.6 mg/dl) have normal ionized Mg values (normal neonatal range 0.40 to 0.56 mmol/L (0.97 to 1.36 mg/dl)); (2) the dose (6.0 mg of elemental Mg/kg) used to correct hypomagnesemia does not lead to elevation of ionized Mg; (3) after intravenous magnesium sulfate infusion, ionized calcium increases in patients with low baseline ionized Mg and decreases in patients with normal baseline ionized Mg. STUDY DESIGN: We recruited 22 neonates with TMg < or = 1.6 mg/dl. They received intravenous sulfate (6 mg elemental Mg/kg) over a 1-hour period. Serum TMg, ionized Mg, and ionized Ca were measured before and after magnesium sulfate infusion. An ion-selective electrode was used to allow direct measurement of ionized Mg and ionized Ca. RESULTS: Thirteen (59%) of 22 neonates with TMg < or = 0.65 mmol/L (1.6 mg/dl) had normal IMg. In 7 (31%) of 22 cases ionized Mg increased slightly above 0.56 mmol/L (1.36 mg/dl); the maximum value was 0.61 mmol/L (1.48 mg/dl). The change in ionized Ca concentrations and the baseline ionized Mg value were inversely correlated (r = -0.79; p < 0.0001). CONCLUSIONS: (1) Measurement of ionized Mg should prevent overdiagnosis and treatment of hypomagnesemia. (2) The dose used in this study is safe. (3) Ionized Mg concentrations are inversely correlated to the response of ionized Ca concentrations to an Mg load.
Assuntos
Deficiência de Magnésio/tratamento farmacológico , Sulfato de Magnésio/uso terapêutico , Magnésio/sangue , Cálcio/sangue , Feminino , Humanos , Recém-Nascido , Infusões Intravenosas , Deficiência de Magnésio/sangue , Deficiência de Magnésio/diagnóstico , Sulfato de Magnésio/administração & dosagem , Masculino , Valores de ReferênciaRESUMO
Clinical or biochemical findings were reevaluated in 34 pediatric patients with primary renal tubular hypokalemic metabolic alkalosis. The patients were subdivided into two groups. Bartter syndrome (primary renal tubular hypokalemic metabolic alkalosis with normocalciuria or hypercalciuria) was diagnosed in 18 patients with molar urinary calcium/creatinine ratios greater than 0.20, and Gitelman syndrome (primary renal tubular hypokalemic metabolic alkalosis with magnesium deficiency and hypocalciuria) was diagnosed in 16 patients with molar urinary calcium/creatinine ratios less than or equal to 0.20 and plasma magnesium levels less than 0.75 mmol/L. Some clinically important differences between the groups were observed. Patients with Bartter syndrome were often born after pregnancies complicated by polyhydramnios (8/18) or premature delivery (7/18) and had short stature (11/18) or polyuria, polydipsia, and a tendency to dehydration (16/18) during infancy (12/18) or before school age (18/18). Patients with Gitelman syndrome had tetanic episodes (12/16) or short stature (3/16) at school age (14/16). We conclude that the Bartter and Gitelman syndromes represent two distinct variants of primary renal tubular hypokalemic metabolic alkalosis and are easily distinguished on the basis of urinary calcium levels.
Assuntos
Alcalose/diagnóstico , Síndrome de Bartter/diagnóstico , Cálcio/urina , Hipopotassemia/diagnóstico , Deficiência de Magnésio/diagnóstico , Alcalose/sangue , Alcalose/genética , Alcalose/urina , Síndrome de Bartter/genética , Bicarbonatos/sangue , Cálcio/sangue , Criança , Pré-Escolar , Cloretos/sangue , Cloretos/urina , Creatinina/urina , Diagnóstico Diferencial , Feminino , Humanos , Hipopotassemia/sangue , Hipopotassemia/genética , Hipopotassemia/urina , Lactente , Recém-Nascido , Sistema Justaglomerular/patologia , Túbulos Renais/patologia , Magnésio/urina , Deficiência de Magnésio/sangue , Deficiência de Magnésio/genética , Deficiência de Magnésio/urina , Masculino , Concentração Osmolar , Fosfatos/sangue , Potássio/urina , Renina/sangue , Convulsões/fisiopatologia , Sódio/sangue , Sódio/urina , Síndrome , Tetania/fisiopatologiaRESUMO
Magnesium (Mg2+) plays a significant role in the electrical stability of the heart and hypomagnesemia may predispose patients to arrhythmias and digitalis toxicity. We measured the serum and skeletal muscle Mg2+ content of patients with chronic Chagasic cardiomyopathy (CCC) during treatment for congestive heart failure and compared it to 15 normal patients who were used to establish the normal values of our population. There is a high frequency of muscle Mg2+ deficiency (66%) in patients with CCC during treatment for heart failure. However, serum Mg2+ is not a sensitive index of deficiency, since hypomagnesemia occurred in only 50% of the patients whose muscle Mg2+ was low. Digitalis toxicity was observed in all muscle Mg2+-deficient patients (100%) and in 25% of patients with normal Mg2+ levels (P less than or equal to 0.05). Ventricular tachycardia (VT) occurred in 75% of muscle Mg2+-deficient patients and in none of the patients with normal magnesium levels (P less than or equal to 0.05). The frequency and severity of premature ventricular contractions (PVC) were higher in muscle Mg2+-deficient patients. We conclude that muscle Mg2+ deficiency is very common in patients with CCC being treated for congestive heart failure and that muscle Mg2+ deficiency defines a higher risk CCC group in terms of digitalis toxicity and severe ventricular arrhythmias such as ventricular tachycardia.