Background: Determination of hydration status in Haemodialysis patients is crucial to correctly assess the dry weight and calculate the amount of excess fluid to be removed by ultrafiltration (UF). The Total Body Water (TBW) can be estimated by different techniques, from mathematical equations to bioimpedance analysis. Several formulas were used to estimate initial Total Body Water (TBW0) based on demographic or anthropometric data. The aim of this study was to compare the different available methods to identify the most objective and reliable method to be used for a correct identification of the TBW in patients undergoing haemodialysis. This work is part of the project DialysIS, founded by a Cross-border Cooperation Programme (INTERREG IT/CH 2007–2013). Methods: TBW0 was calculated by using a classical basic anthropometric formula (TBW-A), the Watson formula (TBW-W) and the Watson formula modified with a correctional term (TBW-Wc), accounting for the part of fluids not drained by the kidneys. The last equation was applied using either real end session weight (TBW-WcR) or the clinically prescribed dry weight (TBW-WcP). TBW0 was computed using the listed methods for 450 haemodialysis sessions pertinent to 70 patients dialyzed in two different dialysis centres (A. Manzoni Hospital, Lecco, Italy; EOC Lugano, Switzerland). Results: The modified Watson formula, thanks to the correctional term, allows obtaining more precise measurements: TBW0 values were comprised between those determined with TBW-A (overestimation) and those achieved by TBW-W (underestimation). The differences among the set of values were statistically significant; exception made for those obtained using TBW-WcR and TBW-WcP. Conclusions: TBW-WcP enables to reach estimations of the TBW initial value comparable to the ones calculated considering the real end session dry weight (TBW-WcR), with the advantage to be suitably used in a predictive algorithm. The anthropometric formula, as well as Watson equation without correctional term, showed to be less robust methods.
Evaluation of the reliability of different methods for the determination of the hydration status in haemodialysis patients
CASAGRANDE, GIUSTINA;BIANCHI, CAMILLA;VITO, DOMENICO;COSTANTINO, MARIA LAURA
2015-01-01
Abstract
Background: Determination of hydration status in Haemodialysis patients is crucial to correctly assess the dry weight and calculate the amount of excess fluid to be removed by ultrafiltration (UF). The Total Body Water (TBW) can be estimated by different techniques, from mathematical equations to bioimpedance analysis. Several formulas were used to estimate initial Total Body Water (TBW0) based on demographic or anthropometric data. The aim of this study was to compare the different available methods to identify the most objective and reliable method to be used for a correct identification of the TBW in patients undergoing haemodialysis. This work is part of the project DialysIS, founded by a Cross-border Cooperation Programme (INTERREG IT/CH 2007–2013). Methods: TBW0 was calculated by using a classical basic anthropometric formula (TBW-A), the Watson formula (TBW-W) and the Watson formula modified with a correctional term (TBW-Wc), accounting for the part of fluids not drained by the kidneys. The last equation was applied using either real end session weight (TBW-WcR) or the clinically prescribed dry weight (TBW-WcP). TBW0 was computed using the listed methods for 450 haemodialysis sessions pertinent to 70 patients dialyzed in two different dialysis centres (A. Manzoni Hospital, Lecco, Italy; EOC Lugano, Switzerland). Results: The modified Watson formula, thanks to the correctional term, allows obtaining more precise measurements: TBW0 values were comprised between those determined with TBW-A (overestimation) and those achieved by TBW-W (underestimation). The differences among the set of values were statistically significant; exception made for those obtained using TBW-WcR and TBW-WcP. Conclusions: TBW-WcP enables to reach estimations of the TBW initial value comparable to the ones calculated considering the real end session dry weight (TBW-WcR), with the advantage to be suitably used in a predictive algorithm. The anthropometric formula, as well as Watson equation without correctional term, showed to be less robust methods.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
