Association between hypervolemia and ventricular hypertrophy in hemodialysis patients

Background: Left ventricular hypertrophy (LVH) is a well-known predictor of cardiovascular mortality in patients who have end-stage renal disease and are maintained on hemodialysis (HD), and LVH is not always correlated with the severity of hypertension in these patients. The purpose of this study was to investigate the role of other factors contributing to LVH.Methods: A total of 50 patients with HD were classified in three groups according to whether their LV mass index (LVMI) was higher than (n = 15), equal to (n = 20), or lower than (n = 15) that predicted by a formula based on their ambulatory blood pressure monitoring (ABPM).Results: Subjects with higher LVMI than predicted had significantly greater inter-HD weight gain (3.4 +/- 0.8 v 2.7 +/- 0.8 and 2.6 +/- 05 kg, respectively, in the other two groups, P < .05), and subjects with lower LVMI than predicted had a tendency toward a more pronounced nocturnal dipping pattern of BP (P = .07 v the other two groups), although daytime and night-time average BP levels did not differ between groups. All other clinical and laboratory parameters were similar among the three groups except higher cardiac output and various indices of LVH, which were more pronounced in the group with higher LVMI by ABPM. This group had also the lowest survival rate over the 2 to 3 years of follow-up, with five deaths versus two in each of the other two groups.Conclusions: the data suggest that correct management of inter-HD weight gain by nutritional counseling and shorter inter-HD intervals may prevent LVH and improve survival independently of BP control. (C) 2004 American Journal of Hypertension, Ltd.

Oxygenation-sensitive cardiovascular magnetic resonance imaging (OS-CMR) : potential confounding factors in use of OS-CMR

La résonance magnétique cardiovasculaire sensible à l'oxygénation (OS-CMR) est devenue une modalité d'imagerie diagnostique pour la surveillance de changements dans l'oxygénation du myocarde. Cette technique offre un grand potentiel en tant qu'outil diagnostic primaire pour les maladies cardiovasculaires, en particulier la détection non-invasive d'ischémie. Par contre, il existe plusieurs facteurs potentiellement confondants de cette technique, quelques-uns d'ordre méthodologique comme les paramètres de séquençage et d'autres de nature physiologiques qui sont peut compris. En raison des effets causés par le contenu tissulaire d'eau, l'état d'hydratation peut avoir un impact sur l'intensité du signal. Ceci est un des aspects physiologiques en particulier dont nous voulions quantifier l'effet confondant par la manipulation de l'état d'hydratation chez des humains et l'observation des changements de l'intensité du signal dans des images OS-CMR. Méthodes: In vitro: Du sang artériel et veineux de huit porcs a été utilisé pour évaluer la dilution en série du sang et son effet correspondant sur l'intensité du signal de la séquence OS. In vivo: Vingt-deux volontaires en santé ont subi OS-CMR. Les concentrations d'hémoglobine (Hb) ont été mesurées au niveau de base et immédiatement après une l'infusion cristalloïde rapide de 1000 mL de solution Lactate Ringer's (LRS). Les images OS-CMR ont été prises dans une vue mid-ventriculaire court axe. L'intensité du signal myocardique a été mesurée durant une rétention respiratoire volontaire maximale, suite à une période d'hyperventilation de 60 secondes. Les changements dans l'intensité du signal entre le début et la fin de la rétention de la respiration ont été exprimés relativement au niveau de base (% de changement). Résultats: L'infusion a résulté en une diminution significative de l'Hb mesurée (142.5±3.3 vs. 128.8±3.3 g/L; p<0.001), alors que l'IS a augmenté de 3.2±1.2% entre les images du niveau de base en normo- et hypervolémie (p<0.05). L'IS d'hyperventilation ainsi que les changements d'IS induits par l'apnée ont été attenués après hémodilution (p<0.05). L'évaluation quantitative T2* a démontré une corrélation négative entre le temps de T2* et la concentration d'hémoglobine (r=-0.46, p<0.005). Conclusions: Il existe plusieurs éléments confondants de la technique OS-CMR qui requièrent de l'attention et de l'optimisation pour une future implémentation clinique à grande échelle. Le statut d'hydratation en particulier pourrait être un élément confondant dans l'imagerie OS-CMR. L'hypervolémie mène à une augmentation en IS au niveau de base et atténue la réponse IS durant des manoeuvres de respiration vasoactives. Cette atténuation de l'intensité du signal devrait être tenue en compte et corrigée dans l'évaluation clinique d'images OS-CMR.

Early initiation of dialysis: mortality and renal function recovery in acute kidney injury patients

INTRODUÇÃO: A decisão de quando iniciar a diálise em pacientes com lesão renal aguda (LRA) que apresentam síndrome urêmica está bem estabelecida, entretanto, com ureia < 200 mg/dl o melhor momento para iniciar a diálise torna-se incerto. OBJETIVO: Este estudo teve como objetivo avaliar a mortalidade e a recuperação da função renal em pacientes com LRA, cujo início da diálise ocorreu em diferentes níveis de ureia. MÉTODOS: Estudo retrospectivo desenvolvido em hospital escola, no estado de São Paulo, Brasil, envolvendo 86 pacientes submetidos à diálise. RESULTADOS: A diálise foi iniciada com uréia > 150 mg/dl em 23 pacientes (grupo I) e uréia > 150 mg/dl em 63 pacientes (grupo II). Hipervolemia e mortalidade foram mais frequentes no grupo I que no grupo II (65,2 x 14,2% - p < 0,05; 39,1 x 68,9% - p < 0,05, respectivamente). Entre os sobreviventes, a recuperação renal foi maior no grupo I (71,4 e 36,8%, respectivamente, p < 0,05). A análise multivariada mostrou risco independente de mortalidade relacionado à sepse, idade > 60 anos, diálise peritoneal e uréia > 150 mg/dl no início da diálise. CONCLUSÃO: Menor mortalidade e maior recuperação renal estão associadas com o diálise iniciada precocemente, conforme baixos níveis de ureia, em pacientes com LRA.

Insuficiência renal aguda. Estudo do quadro clínico e prognóstico.

Acute renal failure (ARF) is a frequent complication in hospitalized patients, and is strongly related to increase of mortality. PURPOSE: To analyze the clinical outcome and the prognostic factors in hospital acquired AFR. METHOD: A prospective study was performed. Data from 200 patients with established ARF admitted during the period of January, 1987 and July, 1990 were collected. RESULTS: The incidence of ARF was 4.9/1000 admissions. Renal ischemia (50%) and nephrotoxic drugs (21%) were the main etiologic factors. The histologic study done in 43 patients showed: acute tubular necrosis (53%), tubular hydrophic degeneration (16%), glomerulopathies (16%) and other lesions (15%). Dialysis therapy was performed in 101 patients and the main indications were: uremia (67%), hypervolemia (22%) and hyperkalemia (9%). The mortality rate was 46.5% and the most important causes of death were: sepsis (38%), respiratory failure (19%) and multiple organs failure (11%). Treatment withdraw was the cause of death in 2 patients. Higher mortality was observed in oliguric patients (62.9%) than non-oliguric (34.5%) (p < 0.05) and in ischemic renal failure (56.7%) when compared to nephrotoxic renal failure (14.7%) (p < 0.05). This difference was maintained when the comparison was done only between dialyzed patients. CONCLUSION: As primary cause of death was not associated to the acute renal failure, we conclude that acute renal failure is an important marker of the gravity of the underlying disease and not the cause of death.

Could albumin level explain the higher mortality in hemodialysis patients with pulmonary hypertension?

Background: The pathogenesis of pulmonary hypertension (PH) in hemodialysis is still unclear. The aim of thisstudy was to identify the risk factors associated with the presence of PH in chronic hemodialysis patients and toverify whether these factors might explain the highest mortality among them.Methods: We conducted a retrospective study of hemodialysis patients who started treatment from August 2001to October 2007 and were followed up until April 2011 in a Brazilian referral medical school. According to theresults of echocardiography examination, patients were allocated in two groups: those with PH and those withoutPH. Clinical parameters, site and type of vascular access, bioimpedance, and laboratorial findings were comparedbetween the groups and a logistic regression model was elaborated. Actuarial survival curves were constructed andhazard risk to death was evaluated by Cox regression analysis.Results: PH > 35 mmHg was found in 23 (30.6%) of the 75 patients studied. The groups differed in extracellularwater, ventricular thickness, left atrium diameter, and ventricular filling. In a univariate analysis, extracellular waterwas associated with PH (relative risk = 1.194; 95% CI of 1.006 1.416; p = 0.042); nevertheless, in a multiple model,only left atrium enlargement was independently associated with PH (relative risk =1.172; 95% CI of 1.010 1.359;p = 0.036). PH (hazard risk = 3.008; 95% CI of 1.285 7.043; p = 0.011) and age (hazard risk of 1.034 per year of age;95% CI of 1.000 7.068; p = 0.047) were significantly associated with mortality in a multiple Cox regression analysis.However, when albumin was taken in account the only statistically significant association was between albuminlevel and mortality (hazard risk = 0.342 per g/dL; 95% CI of 0.119 0.984; p = 0.047) while the presence of PH lost itsstatistical significance (p = 0.184). Mortality was higher in patients with PH (47.8% vs 25%) who also had astatistically worse survival after the sixth year of follow up.Conclusions: PH in hemodialysis patients is associated with parameters of volume overload that sheds light on itspathophysiology. Mortality is higher in hemodialysis patients with PH and the low albumin level can explain thisassociation.© 2012 Greenfield et al.; licensee BioMed Central Ltd.

A randomized clinical trial of high volume peritoneal dialysis versus extended daily hemodialysis for acute kidney injury patients

Background: Acute kidney injury (AKI) requiring dialysis in critically ill patients is associated with an in-hospital mortality rate of 50-80 %. Extended daily hemodialysis (EHD) and high volume peritoneal dialysis (HVPD) have emerged as alternative modalities. Methods: A double-center, randomized, controlled trial was conducted comparing EHD versus HVPD for the treatment for AKI in the intensive care unit (ICU). Four hundred and seven patients were randomized and 143 patients were analyzed. Principal outcome measure was hospital mortality, and secondary end points were recovery of renal function and metabolic and fluid control. Results: There was no difference between the two groups in relation to median ICU stay [11 (5.7-20) vs. 9 (5.7-19)], recovery of kidney function (26.9 vs. 29.6 %, p = 0.11), need for chronic dialysis (9.7 vs. 6.5 %, p = 0.23), and hospital mortality (63.4 vs. 63.9 %, p = 0.94). The groups were different in metabolic and fluid control. Blood urea nitrogen (BUN), creatinine, and bicarbonate levels were stabilized faster in EHD group than in HVPD group. Delivered Kt/V and ultrafiltration were higher in EHD group. Despite randomization, there were significant differences between the groups in some covariates, including age, pre-dialysis BUN, and creatinine levels, biased in favor of the EHD. Using logistic regression to adjust for the imbalances in group assignment, the odds of death associated with HVPD was 1.4 (95 % CI 0.7-2.4, p = 0.19). A detailed investigation of the randomization process failed to explain the marked differences in patient assignment. Conclusions: Despite faster metabolic control and higher dialysis dose and ultrafiltration with EHD, this study provides no evidence of a survival benefit of EHD compared with HVPD. The limitations of this study were that the results were not presented according to the intention to treat and it did not control other supportive management strategies as nutrition support and timing of dialysis initiation that might influence outcomes in AKI. © 2012 Springer Science+Business Media Dordrecht.

Efeitos da redução no conteúdo de sódio da dieta sobre o volume de água corporal e marcadores inflamatórios em pacientes com insuficiência renal crônica em tratamento hemodialítico

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Efeitos da redução da concentração de sódio de diálise sobre o volume de água corporal e marcadores inflamatórios em pacientes com insuficiência renal crônica em tratamento hemodialítico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Hipertensão pulmonar em pacientes com doença renal crônica dialítica está associada com hipervolemia e inflação

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Hipertensão pulmonar em pacientes com doença renal crônica dialítica está associada com hipervolemia e inflação

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Transient Lymphadenopathy Secondary to Nephrotic Syndrome

Mediastinal lymphadenomegaly secondary to hypervolemia is an underdiagnosed tomographic finding. Herein we describe, in a patient with normal cardiac function, findings of pulmonary congestion associated to lymph node enlargement. The nephrotic syndrome causing hypoalbuminemia, low plasma colloid osmotic pressure and augmented transcapillary fluid leakage was the probable cause of the radiological findings.

[Cross-talk between heart and kidney--mechanisms and management of the cardiorenal syndrome from a nephrologists view]

Renal dysfunction represents a frequent comorbidity in patients with in chronic heart failure and is not only a strong predictor of mortality, but also causally linked to the development and progression of CHF. Mechanisms involved in the cross-talk between the kidney and the heart include the up-regulated sympathetic nerve system, activation of the renin-angiotensin-aldosterone system, vasopressin release and decreased activity of arterial baroreceptors and natriuretic peptides resulting in abnormal salt and water retention. The main therapeutic goals for patients with the so-called cardiorenal syndrome is the normalization of volume status while avoiding overdiuresis and renal dysfunction as well as the implementation of an evidence-based pharmacologic treatment to improve patient outcome. If these two goals are not achieved with conventional therapy, renal replacement therapy should be discussed in an interdisciplinary approach. All current renal replacement techniques have proved to be useful in controlling hypervolemia and ameliorating functional cardiac parameters and quality of life in patients with heart failure. Nevertheless, the influence of renal replacement therapy on long-term survival of affected patients has not been addressed in large controlled studies.

Body composition changes assessed by bioelectrical impedance and their associations with functional class deterioration in stable heart failure patients

Background: Heart failure (HF) patients develop important changes in body composition, but only a small number of studies have evaluated the associations between these changes and functional class deterioration in a prospective manner. Objective: The aim of this study was to evaluate whether changes in bioimpedance parameters were associated with NYHA functional class deterioration over six months. Methods: A total of 275 chronic stable HF patients confirmed by echocardiography were recruited. Body composition measurements were obtained by whole body bioelectrical impedance with multiple frequency equipment (BodyStat QuadScan 4000). We evaluated functional class using the New York Heart Association (NYHA) classification at baseline and after six months. Results: According to our results, 66 (24%) subjects exhibited functional class deterioration, while 209 improved or exhibited no change. A greater proportion of patients exhibited higher extracellular water (> 5%), and these patients developed hypervolemia, according to location on the resistance/reactance graph. A 5% decrease in resistance/height was associated with functional class deterioration with an OR of 1.42 (95% CI 1.01-2.0, p = 0.04). Conclusions: Body composition assessment through bioelectrical impedance exhibited a valuable performance as a marker of functional class deterioration in stable HF patients.