VITOR BRITO DA SILVA
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- Hemodynamic Behavior During Hemo-dialysis: Effects of Dialysate Concentrations of Bicarbonate and Potassium(2014) SILVA, Bruno C.; FREITAS, Geraldo R. R.; SILVA, Vitor B.; ABENSUR, Hugo; LUDERS, Claudio; PEREIRA, Benedito J.; OLIVEIRA, Rodrigo B. de; CASTRO, Manuel C. M.; MOYSES, Rosa M. A.; ELIAS, Rosilene M.Background/Aims: Ultrafiltration that occurs during hemodialysis (HD) promotes profound alterations in a relatively short period of time. The dialysate content of bicarbonate (DBic) and potassium (DK) may have impact over intradialytic hemodynamics, which goes beyond ultrafiltration, and its impact was evaluated in a prospective cohort. Methods: 30 patients under HD were submitted to hemodynamic assessment (HA) at the beginning and at the end of HD sessions, through a non-invasive method. Serum minus dialysate potassium concentration was expressed as K-Gap. Cardiac index (CI) and peripheral arterial resistance (PAR) variation (post-HD minus pre-HD) were expressed as Delta CI and Delta PAR. Dialysate content of sodium and calcium were expressed as DNa and DCa, respectively. Results: Mean DNa, DK and DBic were, respectively, 136.4 +/- 1.1, 2.1 +/- 0.6 and 38.2 +/- 2.1 mEq/L. In 15 patients, DCa was > 1.5 mmol/L and in the other 15 patients <= 1.5 mmol/L. The K-Gap ranged from 1.4 to 5.1 mEq/l (median 3.0 mEq/L). There was a reduction in post-HD CI and systolic blood pressure (Delta CI = -0.72l/min/m(2) and -11.3 +/- 15.1 mmHg, respectively, p < 0.001 for both). Conversely, Delta PAR increased (Delta PAR = 272dyn.s/cm(5), p < 0.001). Lower post-HD CI was was associated to higher DBic (p = 0.0013) and lower K-Gap (p = 0.026). In multivariate analysis, Delta CI was dependent on DBic and K-Gap, whereas Delta PAR was dependent on dialysate calcium during HD. Conclusion: We confirmed that Na and Ca dialysate content exerts and important role on hemodynamic during HD. In addition, our findings pointed out that higher dialysate concentrations of bicarbonate and potassium promote lower cardiac performance at the end of hemodialysis session.
- Parathyroidectomized patients have impaired capacity of peripheral vascular constriction during hemodialysis(2016) SILVA, Bruno C.; MOYSES, Rosa M. A.; SILVA, Vitor B.; FREITAS, Geraldo R. R.; ELIAS, Rosilene M.Parathyroidectomy (PTx) seems to improve cardiovascular outcomes and reduce blood pressure levels. However, the effect of PTx on hemodynamic changes during hemodialysis (HD) is still overlooked. This was a prospective cohort design. Patients with end-stage renal disease on maintenance HD were included. Diabetes and nonsinusal rhythm were exclusion criteria. History of PTx was recorded. Finometer monitor was used to access parameters immediately pre- and post-HD sessions. Cardiac index (CI) variation (CI) and peripheral arterial resistance variation (PAR) were the variables of interest. Biochemical and echocardiographic data were also obtained. PTx patients (n=11) were matched to non-PTx patients (n=20). PAR was lower in PTx group in comparison with non-PTx group (P=0.039), which was independent of parathyroid hormone (PTH) levels. Multiple regression analysis showed that PTx, CI, and dialysate calcium remained independently associated with PAR variation and even adjusted for ultrafiltration rate (adjusted r(2)=0.64). In conclusion, parathyroidectomized patients have impaired capacity of vasoconstriction in response to ultrafiltration, an effect independent of serum PTH levels. Further studies are needed to elucidate mechanisms explaining the interaction between PTx and systemic vascular tonus.
- High Dialysate Calcium Concentration is Associated with Worsening Left Ventricular Function(2019) SILVA, V. B.; MACEDO, T. A.; BRAGA, T. M. S.; SILVA, B. C.; GRACIOLLI, F. G.; V, W. Dominguez; DRAGER, L. F.; MOYSES, R. M.; ELIAS, R. M.Dialysate calcium concentration (d[Ca]) might have a cardiovascular impact in patients on haemodialysis (HD) since a higher d[Ca] determines better hemodynamic tolerability. We have assessed the influence of d[Ca] on global longitudinal strain (GLS) by two-dimensional echocardiography using speckle-tracking imaging before and in the last hour of HD. This is an observational crossover study using d[Ca] 1.75 mmol/L and 1.25 mmol/L. Ultrafiltration was the same between interventions; patients aged 44 +/- 13 years (N = 19). The 1.75 mmol/L d[Ca] was associated with lighter drop of blood pressure. Post HD serum total calcium was higher with d[Ca] 1.75 than with 1.25 mmol/L (11.5 +/- 0.8 vs. 9.1 +/- 0.5 mg/dL, respectively, p < 0.01). In almost all segments strain values were significantly worse in the peak HD with 1.75 mmol/L d[Ca] than with 1.25 mmol/L d[Ca]. GLS decreased from -19.8 +/- 3.7% at baseline to -17.3 +/- 2.9% and -16.1 +/- 2.6% with 1.25 d[Ca] and 1.75 d[Ca] mmol/L, respectively (p < 0.05 for both d[Ca] vs. baseline and 1.25 d[Ca] vs. 1.75 d[Ca] mmol/L). Factors associated with a worse GLS included transferrin, C-reactive protein, weight lost, and post dialysis serum total calcium. We concluded that d[Ca] of 1.75 mmol/L was associated with higher post dialysis serum calcium, which contributed to a worse ventricular performance. Whether this finding would lead to myocardial stunning needs further investigation.