The role of urea-induced osmotic diuresis and hypernatremia in a critically ill patient: case report and literature review / O papel da diurese osmótica induzida por ureia na geração de hipernatremia no paciente crítico: relato de caso e revisão da literatura

Abstract Hypernatremia is a common electrolyte problem at the intensive care setting, with a prevalence that can reach up to 25%. It is associated with a longer hospital stay and is an independent risk factor for mortality. We report a case of hypernatremia of multifactorial origin in the intensive care setting, emphasizing the role of osmotic diuresis due to excessive urea generation, an underdiagnosed and a not well-known cause of hypernatremia. This scenario may occur in patients using high doses of corticosteroids, with gastrointestinal bleeding, under diets and hyperprotein supplements, and with hypercatabolism, especially during the recovery phase of renal injury. Through the present teaching case, we discuss a clinical approach to the diagnosis of urea-induced osmotic diuresis and hypernatremia, highlighting the utility of the electrolyte-free water clearance concept in understanding the development of hypernatremia.

Resumo A hipernatremia é um distúrbio eletrolítico comum no ambiente de terapia intensiva, com uma prevalência que pode chegar a 25%. Está associada a maior tempo de internação hospitalar e é um fator de risco independente para a mortalidade. Este relato ilustra um caso de hipernatremia de origem multifatorial no ambiente de terapia intensiva. Destacaremos o papel da diurese osmótica por geração excessiva de ureia, uma causa de hipernatremia pouco conhecida e subdiagnosticada. Este cenário pode estar presente em pacientes em uso de elevadas doses de corticoides, com sangramento gastrointestinal, em uso de dietas e suplementos hiperproteicos e estado de hipercatabolismo, especialmente durante a fase de recuperação de injúria renal. A seguir, discutiremos uma abordagem clínica para o diagnóstico da hipernatremia secundária à diurese osmótica induzida por ureia, destacando a importância do conceito de clearance de água livre de eletrólitos nesse contexto.

Fluid balance in pediatric patients in prone position: a pragmatic study

SUMMARY OBJECTIVE: To verify the association between prone position, increased diuresis, and decreased cumulative fluid balance in critically ill pediatric patients who underwent mechanical ventilation (MV) for pulmonary causes and describe adverse events related to the use of the position. METHODS: This is a retrospective observational study. Patients aged between 1 month and 12 years who underwent MV for pulmonary causes, between January 2013 and December 2015, were selected and divided between those who were put on prone position (PG) and those who were not (CG) during the hospitalization at the Pediatric Intensive Care Unit (PICU). Data were analyzed longitudinally from D1 to D4. RESULTS: A total of 77 patients (PG = 37 and CG = 40) were analyzed. The general characteristics of both groups were similar. In the comparison between the groups, there was no increase in diuresis or decrease in cumulative fluid balance in the prone group. In the longitudinal analysis of D1 to D4, we saw that the PG presented higher diuresis (p = 0.034) and a lower cumulative fluid balance (p = 0.001) in D2. Regarding the use of diuretics, there was greater use of furosemide (P <0.001) and spironolactone (P = 0.04) in the PG. There was no increase in adverse events during the use of the prone position. CONCLUSION: The prone position was not associated with increased diuresis or decreased cumulative fluid balance in critically ill pediatric patients who underwent to MV for pulmonary causes.

RESUMO OBJETIVO: Verificar a associação entre posição prona, aumento da diurese e diminuição do balanço hídrico em pacientes pediátricos criticamente enfermos e submetidos à ventilação mecânica (VM) por causa pulmonar, além de descrever eventuais intercorrências relacionadas à aplicação dessa posição. MÉTODOS: Estudo observacional retrospectivo. Pacientes submetidos à VM por causa pulmonar, com idade entre 1 mês e 12 anos no período entre janeiro de 2013 e dezembro de 2015, foram selecionados e divididos entre os que receberam posição prona (GP) e os que não receberam (GC) durante a internação na Unidade de Terapia Intensiva Pediátrica (Utip). Os dados foram analisados longitudinalmente de D1 a D4. RESULTADOS: Foram analisados77 pacientes (GP=37 e GC=40). Em termos de características gerais, os grupos foram semelhantes entre si. Na comparação entre os grupos, não houve aumento da diurese ou diminuição do balanço hídrico cumulativo no grupo prona. Na análise longitudinal de D1 a D4, evidenciou-se que o GP apresentou maior diurese (p=0,034) e menor balanço hídrico cumulativo (p = 0,001) no D2. Com relação ao uso de diuréticos, houve maior uso de furosemida (P<0,001) e de espironolactona (P=0,04) no GP. Não houve aumento de eventos adversos durante a utilização da posição prona. CONCLUSÃO: A posição prona não demonstrou associação com aumento da diurese ou diminuição de balanço hídrico cumulativo em pacientes críticos pediátricos submetidos à VM por causa pulmonar.

Efeitos agudos da ingestão de bebidas energéticas sobre os paramêtros hidro-eletrolíticos durante exercício em esteira / Acute effects of energy drink intake on hydro-electrolytic parameters during the exercise on a treadmill

RESUMO O objetivo do estudo foi verificar se bebidas enegéticas com diferentes composições nutricionais afetam o balanço hidro-eletrolítico de corredores de resistência. Doze homens participaram desse estudo duplo cego e crossover randomizado, ingerindo 3mg.kg-1 de cafeína de bebida energética convencional e sugar free, e um placebo carboidratado e não cafeinado, 40 minutos antes de sessão de exercício em ambiente termoneutro. Em cada situação experimental, os avaliados realizaram exercício de corrida em esteira com duração de 60 minutos e intensidade constante entre 65 e 75% do VO2max, seguidos por um sprint correspondendo a 100% do VO2max até a exaustão. Foram avaliados o peso corporal (PC), desidratação absoluta e relativa, densidade da urina, taxa de sudorese e níveis de Na+, K+ e hematócrito. Durante o exercício os avaliados receberam somente água a cada 15 minutos. Foi verificada alteração nos níveis de densidade da urina antes e depois do exercício para todos os tratamentos (p<0,05). Não houve diferença significativa entre as bebidas nos níveis de Na+, K+ e hematócrito (p>0,05) mantendo-se dentro dos níveis de normalidade. Conclui-se que diferentes tipos de bebidas energéticas não afetam o balanço hidro-eletrolítico de corredores de resistência ao longo do exercício.

ABSTRACT This work compares the effects promoted by energy drinks with diferente nutricional compositions on the hydro-electrolytic balance of resistance runners. Twelve men participated in this double blinded, randomized crossover study, ingesting 3mg*Kg-1 of a conventional energy drink with caffeine or sugar-free, and a placebo 40-minutes before tests on thermoneutral environment. The duration of the session was 60 minutes with constant intensity between 65 and 75% of VO2max, followed by a sprint corresponding to 100% of VO2max until exhaustion. There were evaluated body weight (BW), absolute and relative dehydration, urine density, sweating rate and Na+, K+ and hematocrit levels. During the exercise, the participants drunk only water every 15 minutes. Changes in urine density levels were observed before and after exercise for all procedures (p <0.05). There was no significant difference on the levels of Na+, K+ and hematocrit between the drinks (p> 0.05), remaining within normal levels. It is concluded that different types of energy drinks do not affect the hydro-electrolytic balance of resistance runners during the exercise.

Remifentanil does not increase urine output during oral surgery, contrary to its effect during other surgeries - a cohort study / Remifentanil não aumenta a diurese durante cirurgia oral, contrariamente ao seu efeito durante outras cirurgias - estudo de coorte

Abstract Background: An increase in urine output by remifentanil injection during laparoscopic procedures and surgeries such as cardiac and gynecological procedures, due to suppression of the stress response to surgery, has been reported. The aim of our prospective, observational, cohort study was to assess the effect of remifentanil analgesia on urine output during dental and minor oral surgery by comparing intraoperative urine output under defined infusion volumes with and without the use of remifentanil. Methods: Dental patients aged 16 years or older, American Society of Anesthesiologists physical status 1, with no renal diseases or abnormal blood values of serum creatinine and BUN, not on treatment with diuretic drugs, and undergoing minor oro-maxillofacial surgery or dental treatment under inhalation general anesthesia were included in this study. Urethral catheterization was performed after anesthesia induction, and urine output was measured every 30 minutes. We measured urine volume (mL) and rate of urine output (mL.kg-1.h-1) intraoperatively, and compared these parameters between patients who did and did not receive remifentanil during the intraoperative period. Results: Eighty-seven patients were categorized into the remifentanil group (n = 43) or remifentanil non-use group (n = 44). Both volume of urine (mL) and rate of urine output (mL.kg-1.h-1) were not significantly different between the two groups (remifentanil group, 372.3 ± 273.5 mL, 1.8 ± 1.1 mL.kg-1.h-1; remifentanil non-use group, 343.3 ± 283.3 mL, 1.9 ± 1.2 mL.kg-1.h-1; p = 0.63; 0.57). Conclusion: Our results show that use of remifentanil during dental and minor oral surgeries does not increase urine output.

Resumo Justificativa: Foi relatado um aumento na diurese após a injeção de remifentanil durante procedimentos laparoscópicos e cirurgias cardíacas e ginecológicas, devido à supressão da resposta ao estresse da cirurgia. O objetivo de nosso estudo prospectivo, observacional e de coorte foi avaliar o efeito da analgesia com remifentanil sobre a diurese durante cirurgia odontológica e oral de pequeno porte e comparar a diurese no intraoperatório sob infusão de volumes definidos, com e sem o uso de remifentanil. Métodos: Pacientes odontológicos ≥ 16 anos, estado físico ASA I, sem doenças renais ou valores sanguíneos anormais de creatinina sérica e ureia, sem tratamento com diuréticos e submetidos à cirurgia bucomaxilofacial de pequeno porte ou tratamento odontológico sob anestesia geral inalatória foram incluídos neste estudo. Cateterismo uretral foi feito após a indução da anestesia e a diurese foi medida a cada 30 min. Medimos o volume de urina (mL) e a taxa de diurese (mL.kg-1.h-1) no intraoperatório e comparamos esses parâmetros entre os pacientes que receberam e que não receberam remifentanil durante o período intraoperatório. Resultados: Foram designados 87 pacientes para os grupos com remifentanil (n = 43) ou grupo sem remifentanil (n = 44). O volume de urina (mL) e a taxa de diurese (mL.kg-1.h-1) não foram significativamente diferentes entre os dois grupos (grupo com remifentanil: 372,3 ± 273,5 mL, 1,8 ± 1,1 mL.kg-1.h-1; grupo sem remifentanil: 343,3 ± 283,3 mL, 1,9 ± 1,2 mL.kg-1.h-1; p = 0,63; 0,57). Conclusão: Nossos resultados mostram que o uso de remifentanil durante as cirurgias odontológicas e de pequeno porte não aumenta a diurese.

[Remifentanil does not increase urine output during oral surgery, contrary to its effect during other surgeries - a cohort study]. / Remifentanil não aumenta a diurese durante cirurgia oral, contrariamente ao seu efeito durante outras cirurgias ­ estudo de coorte.

BACKGROUND: An increase in urine output by remifentanil injection during laparoscopic procedures and surgeries such as cardiac and gynecological procedures, due to suppression of the stress response to surgery, has been reported. The aim of our prospective, observational, cohort study was to assess the effect of remifentanil analgesia on urine output during dental and minor oral surgery by comparing intraoperative urine output under defined infusion volumes with and without the use of remifentanil. METHODS: Dental patients aged 16 years or older, American Society of Anesthesiologists physical status 1, with no renal diseases or abnormal blood values of serum creatinine and BUN, not on treatment with diuretic drugs, and undergoing minor oro-maxillofacial surgery or dental treatment under inhalation general anesthesia were included in this study. Urethral catheterization was performed after anesthesia induction, and urine output was measured every 30minutes. We measured urine volume (mL) and rate of urine output (mL.kg-1.h-1) intraoperatively, and compared these parameters between patients who did and did not receive remifentanil during the intraoperative period. RESULTS: Eighty-seven patients were categorized into the remifentanil group (n=43) or remifentanil non-use group (n=44). Both volume of urine (mL) and rate of urine output (mL.kg-1.h-1) were not significantly different between the two groups (remifentanil group, 372.3±273.5mL, 1.8±1.1mL.kg-1.h-1; remifentanil non-use group, 343.3±283.3mL, 1.9±1.2mL.kg-1.h-1; p=0.63; 0.57). CONCLUSION: Our results show that use of remifentanil during dental and minor oral surgeries does not increase urine output.

[Predictors of physical incapacity degree to chronic hemodialysis patients in Kinshasa : Key role of the residual diuresis]. / Prédicteurs du degré d'incapacité physique chez les hémodialysés de Kinshasa : rôle primordial de la diurèse résiduelle.

OBJECTIVE: Identifying predictors of physical incapacity degree in patients on chronic hemodialysis in Kinshasa. METHODS: Bicentric analytical study, between January 2007 and July 2013. Degree of physical handicap was evaluated at 6months of hemodialysis based on the scale of Rosser. Logistic regression sought the predictors of no or light physical incapacity (Rosser<3) vs. moderate to maximum (Rosser≥3). P was set at 0.05. RESULTS: One hundred twenty-seven patients (127) patients received at least 6months of hemodialysis (53.3±11years; 73.2 % male), 79 (62.2 %) had no or light incapacity and 48 (37.8 %) moderate to maximum. Predictors of lower physical incapacity in univaried analysis were: secured funding, high socioeconomic level, lack of diabetes mellitus, high body weight, normal systolic and diastolic blood pressure, residual diuresis 3months later, hemoglobin and hematocrit, low comorbidity, arteriovenous fistula, erythropoietin, at least 12hours of hemodialysis per week and lack of intradialytic complications. After logistic regression, a high residual diuresis 3months of hemodialysis has proved an independent predictor of lower physical Incapacity (aOR 0.998; P=0.024) next to the lack of diabetes mellitus (aOR 0.239; P=0.024), good control of systolic (aOR 0.958; P=0.013) and diastolic (aOR 1.089; P=0.003) blood pressure and the use of erythropoietin (aOR 5.687; P=0.004). CONCLUSION: Preserving residual diuresis is associated with lower physical incapacity and must be integrated in the management in hemodialysis.

Postexercise rehydration with beer impairs fluid retention, reaction time, and balance.

Beer is promoted by popular media as a good choice for rehydration, but there is limited support for the claim. To assess the effect of beer alcohol on rehydration and motor control, 11 young (24.4 ± 3.7 years old) males of legal drinking age were dehydrated to 2.12% ± 0.20% body mass (mean ± SD) by exercising in a climatic chamber (31.7 ± 1.6 °C, 55.0% ± 8.3% relative humidity) on 3 different days, 1 week apart, and rehydrated with 100% of their sweat loss using water (WATER), 4.6% alcohol beer (BEER), or low-alcohol beer (LAB), in random order. Urine output, blood alcohol content (BAC), reaction time (RT), and balance (as measured by center of pressure velocity (VCoP)) were measured every 30 min over 3 h and compared via 2-way, repeated-measures analyses of variance (ANOVAs). After consuming ≈1.6 L in 1 h, urine output was greater for BEER (1218 ± 279 mL) than for LAB (745 ± 313 mL, p = 0.007) and WATER (774 ± 304 mL, p = 0.043). BAC remained at 0 with WATER and LAB; with BEER, BAC reached 0.857 g/L (95% confidence intervals [0.752, 0.963]) immediately postrehydration. RT was longer for BEER (0.314 ± 0.039 s) than for LAB (0.294 ± 0.034 s, p = 0.009), but was no different from WATER (0.293 ± 0.049 s, p = 0.077). VCoPx was significantly higher for BEER (0.0284 ± 0.0020 m/s) compared with LAB (0.0233 ± 0.0010 m/s) or WATER (0.0238 ± 0.0010 m/s) (p = 0.022), but VCoPy was not different among beverages. In conclusion, rehydration with BEER resulted in higher diuresis, slower RT, and impaired VCoP than rehydration with LAB or WATER.

Ingestão dietética, excreção urinária de 24 horas de Na e K e risco cardiovascular em hipertensos / Dietary intake, urinary excretion of 24 hours of Na and K and cardiovascular risk in hypertensive

Este estudo teve por objetivo avaliar a ingestão dietética (ID) de sódio (Na) e potássio (K) por meio de inquérito alimentar e da excreção em urina de 24 horas (EU24H) e verificar sua associação com fatores de risco cardiovascular em hipertensos. Trata-se de um estudo transversal com 76 pacientes hipertensos, com dados coletados em dois momentos em espaço temporal de 1 ano, avaliados quanto aos dados sociodemográficos, antropométricos (índice de massa corporal e circunferência da cintura), bioquímicos (colesterol, triglicerídeos e glicemia de jejum), clínicos (uso de medicação anti-hipertensiva ou não) e dietéticos (ID e EU24h de Na e K). Para a análise dos dados, foram utilizados coeficiente de correlação de Spearman (técnicas de estatística descritiva), os testes t de Student e de Mann-Withney e ANOVA seguidos de testes de Tukey, adotandose um nível de significância de 5%. Os grupos apresentaram em comum maior frequência de pessoas do gênero feminino, idosas, com colesterol total (CT) elevado, assim como elevado índice de obesidade abdominal (OA), numa população de classe socioeconômica baixa. Observou-se que o uso de medicamentos anti-hipertensivos não influenciaram a EU de Na e K. Merecem destaque ainda as importantes diferenças entre o padrão de consumo quando avaliados pela EU e pelo IDR24h, o que mostra a importância do uso de biomarcadores para quantificar a real ingestão dos nutrientes estudados diante da variabilidade da ID e dos vieses em quantificar a ID pelo IDR24h. Os dados obtidos por meio da excreção urinária revelaram alto consumo de Na e baixo de K, demonstrando que tal população apresenta ingestão dietética inadequada.

This study aimed to evaluate the dietary intake (DI) of sodium (Na) and potassium (K) through food intake and excretion in urine of 24H (EU24H) and verify its association with cardiovascular risk factors in hypertensive patients. This is a cross-sectional study on hypertensive, 76 patients, with data collected at two points with the timeline of one year, assessed for socio-demographic data, anthropometric (body mass index and waist circumference), biochemical (cholesterol, triglycerides and fasting glucose), clinical (use of antihypertensive medication or not) and dietary (DI and UE24h and Na and K). For data analysis we used the Spearman correlation coefficient (Descriptive statistical techniques), the Student's t-test and Mann-Whitney test and ANOVA followed by Tukey test adopting a significance level of 5%. The groups had in common a higher frequency of female persons, the elderly, with high cholesterol, high frequency of abdominal obesity in a population of lower socioeconomic class. It was observed that the use of antihypertensive medications did not influence the Na and K UE. Moreover, we stress the important differences between the pattern of consumption when evaluated by the UE and the DIR24h, which demonstrates the importance of using biomarkers to quantify the actual intake of nutrients due to the variability of the DI and quantify the biases in the DIR24h. The data obtained from urinary excretion showed a high consumption of low Na and K, showing that this population has inadequate dietary intake.

Morfologia e função cardíacas em pacientes renais crônicos, com ou sem diurese residual, em tratamento hemodialítico / Cardiac morphology and function in patients with and without residual diuresis on hemodialysis

Em pacientes com doença renal crônica (DRC) em hemodiálise (HD), a hipertrofia ventricular esquerda (HVE) está relacionada ao aumento do índice de resistência vascular periférica (IRVP) total e à sobrecarga de volume. A presença da diurese residual (DR) nesses pacientes possibilita maior controle volêmico. Avaliamos as modificações morfofuncionais do ventrículo esquerdo (VE) em pacientes com DRC em HD com e sem diurese residual. Trinta e um pacientes não diabéticos foram divididos em dois grupos: com diurese residual (DR+) (n = 17) e sem diurese residual (DR-) (n = 14). Em ambos os grupos, DR+ vs. DR-, ocorreram diferenças no índice cardíaco (3,9 ± 0,20 vs. 3,0 ± 0,21 L/min/m²; p = 0,0056), no índice sistólico (54 ± 2,9 vs. 45 ± 3,3 mL/b/m²; p = 0,04), no volume diastólico final (141 ± 6,7 vs. 112 ± 7,6 mL; p = 0,008), no diâmetro diastólico final (52 ± 0,79 vs. 48 ± 1,12 mm; p = 0,0072) e no IRVP total (1.121 ± 56 vs. 1.529 ± 111 dina.seg.cm-5; p = 0,001). O grupo DR+ apresentou menor espessamento relativo de parede (ERP) do que o DR- (0,38 ± 0,01 vs. 0,45 ± 0,01; p = 0,0008). A fração de ejeção (66,00 ± 1,24 vs. 66,0 ± 1,46 por cento; p = 0,873) e o índice de massa ventricular esquerda (132 ± 6,0 vs. 130 ± 8,3 g/m; p = 0,798) foram similares em ambos os grupos. O volume de diurese residual correlacionou-se com o espessamento da parede ventricular (r = 0,42; p = 0,0186) e com o índice de resistência vascular periférica (r = -0,48; p = 0,0059). Em conclusão, a presença ou não da diurese residual, em pacientes com doença renal crônica e em hemodiálise, pode ser responsável por modificações na função cardíaca sistólica.

In patients with chronic renal failure on hemodialysis, left ventricular hypertrophy is related to the increase in total peripheral vascular resistance and volume overload. The presence of residual diuresis enables greater control of the volemia of these. We evaluated the morpho-functional changes of the left ventricle in patients with chronic kidney disease on hemodyalisis treatment with and without residual diuresis. A total of 31 non diabetic patients were studied and they were divided into two groups: with residual diuresis (RD+) (n = 17) and without residual diuresis (RD-) (n = 14). In both groups, RD+ vs. RD-, using data from a Doppler echocardiogram differences were found, respectively, in the cardiac index (3.9 ± 0.2 vs. 3.0 ± 0.2 L/min/m²; p = 0.0056), systolic index (54 ± 2.9 vs. 45 ± 3.3 mL/b/m²; p = 0.04), end diastolic volume (141 ± 6.7 vs. 112 ± 7.6 mL; p = 0.008), end diastolic diameter (52 ± 0.7 vs. 48 ± 1.1 mm; p = 0.0072) and total peripheral resistance index (1121 ± 56 vs. 1529 ± 111 dyne.sec.cm-5; p = 0.001). RD+ had lower relative wall thickness than RD- (0.38 ± 0.01 vs. 0.45 ± 0.01; p = 0.0008). The ejection fraction and the left ventricular mass index were similar in both groups. The urinary 24-hour volume correlated with the relative wall thickness (r = -0.42; p = 0.0186) and with peripheral resistance index (r = -0.48; p = 0.0059). In conclusion, there were distinct ventricular geometric patterns and different functional performances between RD+ and RD- groups. The presence of residual diuresis can be responsible by these modifications in systolic function.