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E Garrigos

Publications and source records attributed to E Garrigos.

4 recordsLinked to original sources
PubMed1998

Urea reduction ratio considering urea rebound.

An American National Study shows that survival benefits from higher dialysis doses appear to be present up to a Kt/V level of 1.3 or a urea reduction ratio (URR) of 70%. The effect of increasing dialysis efficiency magnified urea rebound and the error in URR determinations. Several formulas have been developed to calculate URR considering the urea rebound (URRr). Smye and coworkers have proposed a method whereby the equilibrated blood urea nitrogen is predicted by additional intradialytic urea sample. Maduell and colleagues, based on analysis of postdialysis urea rebound, have proposed a method whereby the urea rebound is predicted. To compare measured URRr to estimated by Smye and Maduell formulas, 384 patients were studied, 211 males and 173 females, who received a dialysis session with their habitual parameters. Measurements of plasma urea concentration were obtained at the beginning, 90-100 min following the start of dialysis, at the end, and 45 min after dialysis. The postdialysis urea rebound was 22.4+/-9.7%. The urea kinetic model Kt/V was 1.365+/-0.26, and Kt/Vr was 1.14+/-0.23. URR was 68.7+/-6.6%, and when it was calculated with urea rebound, it decreased to 61.9+/-7.4%. The URRr correlated with calculations by Smye and Maduell formulas: 60.7+/-8.4 (r = 0.722, p < 0.001) and 61.8+/-6.6 (r = 0.933, p < 0.001), respectively. The precision of estimated limits of agreement and percentage of error by Bland and Altman analysis show that URRr estimated Maduell formula could be used in place of the URRr. Otherwise, the degree of agreement of the Smye method was not clinically acceptable. In conclusion, our results led us to suggest that in actual dialysis, the use of URR is not adequate for delivered hemodialysis dose, and URRr should be used. URRr estimated by Maduell formula could be a simple and accurate method for use in clinical practice. The recommended dialysis dose by the American National Study of URR of 70% could correspond, considering urea rebound, to Kt/Vr 1.18 or URRr of 64%.

Adult↗
PubMed1997

Validation of different methods to calculate Kt/V considering postdialysis rebound.

BACKGROUND: The effect of increasing dialysis efficiency magnifies rebound urea and the error in Kt/V determinations from single pool urea kinetics. Several formulae have been developed to calculate Kt/V taking into account the rebound urea (Kt/Vr). Smye et al. proposed a method whereby the equilibrated BUN is predicted by an additional intradialytic urea sample (Kt/VrSmye). Daugirdas et al. proposed a method where a single pool Kt/V is modified according to the speed of dialysis to obtain a double pool Kt/V (Kt/VrDaug). Maduell et al. developed a method based on analysis of post-dialysis urea rebound whereby the Kt/Vr is predicted according to the single pool Kt/V and K/V (Kt/VrMad). DESIGN OF THE STUDY: We compared Kt/Vr estimated by these three formulae (Smye, Daugirdas, and Maduell) in 384 patients consisting of 211 males and 173 females, who received dialysis according to their regular protocols. Plasma urea was measured at the beginning, 90-100 min following the start of dialysis, the end, and 45 min post-dialysis. RESULTS: Post-dialysis rebound urea was 22.4 +/- 9.7%. Kt/V and Kt/Vr obtained with rea kinetic model Kt/V 1.184 +/- 0.22 and 0.984 +/- 0.20, respectively. These was a good correlation between Kt/Vr and the Smye formula (Kt/VrSmye = 0.956 +/- 0.21, r = 0.729, P < 0.001), and a better one for Daugirdas (Kt/VrDaug = 0.984 +/- 0.18, r = 0.931, P < 0.001), and Maduell formulae (Kt/VrMad = 0.980 +/- 0.18, r = 0.946, P < 0.001). Limits of agreement and percentage of error estimated according to Bland and Altman show that Kt/Vr estimated by Daugirdas and Maduell formulae could be used in place of the Kt/Vr. The degree of agreement with the Smye method is not clinically acceptable. CONCLUSION: Our results suggest that the use of a single pool Kt/V is not adequate to estimate the haemodialysis dose delivered and Kt/V taking rebound urea in consideration. Kt/Vr estimated by Daugirdas or Maduell formulae are a simple and accurate method for use in clinical practice.

Adult↗