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. May-Jun 2019;45(3):588-604.
doi: 10.1590/S1677-5538.IBJU.2018.0701.

Predicting Urine Output After Kidney Transplantation: Development and Internal Validation of a Nomogram for Clinical Use

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Free PMC article

Predicting Urine Output After Kidney Transplantation: Development and Internal Validation of a Nomogram for Clinical Use

Aderivaldo Cabral Dias Filho et al. Int Braz J Urol. .
Free PMC article

Abstract

Purpose: To analyze pre-transplantation and early postoperative factors affecting post-transplantation urine output and develop a predictive nomogram.

Patients and methods: Retrospective analysis of non-preemptive first transplanted adult patients between 2001-2016. The outcomes were hourly diuresis in mL/Kg in the 1st (UO1) and 8th (UO8) postoperative days (POD). Predictors for both UO1 and UO8 were cold ischemia time (CIT), patient and donor age and sex, HLA I and II compatibility, pre-transplantation duration of renal replacement therapy (RRT), cause of ESRD (ESRD) and immunosuppressive regimen. UO8 predictors also included UO1, 1st/0th POD plasma creatinine concentration ratio (Cr1/0), and occurrence of acute cellular rejection (AR). Multivariable linear regression was employed to produce nomograms for UO1 and UO8.

Results: Four hundred and seventy-three patients were included, mostly deceased donor kidneys' recipients (361, 70.4%). CIT inversely correlated with UO1 and UO8 (Spearman's p=-0.43 and -0.37). CR1/0 inversely correlated with UO8 (p=-0.47). On multivariable analysis UO1 was mainly influenced by CIT, with additional influences of donor age and sex, HLA II matching and ESRD. UO1 was the strongest predictor of UO8, with significant influences of AR and ESRD.

Conclusions: The predominant influence of CIT on UO1 rapidly wanes and is replaced by indicators of functional recovery (mainly UO1) and allograft's immunologic acceptance (AR absence). Mean absolute errors for nomograms were 0.08 mL/Kg h (UO1) and 0.05 mL/Kg h (UO8).

Keywords: Delayed Graft Function; Kidney Transplantation; Nomograms.

Conflict of interest statement

None declared.

Figures

Figure 1
Figure 1. Visual representation of the intervals in which the response variable - urine output - was collected (light gray).
Tx, transplantation, or postoperative day 0; UO1, urinary output from 6 a.m. of postoperative day 1 (POD1) to 6 a.m. of postoperative day 2 (POD2); UO8, urinary output from 6 a.m. of postoperative day 8 (POD8) to 6 a.m. of postoperative day 9 (POD9); POD 3 to 7, postoperative days 3 to 7.
Figure 2
Figure 2. Matrix of pairwise scatterplots with loess regression lines (in red) and Spearman correlation coefficients (under the main diagonal). UO1, urinary output from 6 a.m. of postoperative day 1 (POD1) to 6 a.m. of postoperative day 2; UO8, urinary output from 6 a.m. of postoperative day 8 (POD8) to 6 a.m. of postoperative day 9; CIT, cold ischemia time in hours; pt age, patient age in years; donor age, age of donor in years; pt sex, patient sex; D sex, donor sex; HLA I, number of Class I HLA antigen mismatches (0, 3-1, 4); HLA II, number of Class II HLA antigen mismatches loci (0, 1, 2); dialysis, duration of renal replacement therapy before kidney transplantation; RRT, duration in years of renal replacement therapy before transplantation; ESRD, cause of ESRD aggregated in systemic, renal, urologic, autossomic dominant polycystic disease (ADPKD) and undetermined; D Cr, donor plasma creatinine in mg%; type of donor, whether the kidney came from a Deceased (vascular or non-vascular) or Living-Related donor; PRA, panel of reactive antibodies in %.
Nomogram to predict UO1. In order to obtain the predicted hourly urinary output in mL/Kg, the user identifies each predictors’ values in their respective axes and uses a straightedge to approximate its score in the Points axis. All predictors values are added and this total score is identified in the Total Points axis. The predicted hourly urinary output can then be estimated in the UO1 mL/Kg h axis, also with a straightedge. This operation is considerably simplified with the use of a caliper. HLA DR, mismatches on the DR locus; IS, initial immunosuppression: csa_aza, cyclosporine + azathioprine; csa_mmf, cyclosporine + mycophenolate; fk_mmf, tacrolimus + mycophenolate; fk_aza, tacrolimus+azathioprine; thymo, thymoglobulin; no_calc_inhibitor, no calcineurin inhibitor.
Figure 3
Figure 3. Nomogram to predict UO8.
In order to obtain the predicted hourly urinary output in mL/Kg, the user identifies each predictors’ values in their respective axes and uses a straightedge to approximate its score in the Points axis. All predictors values are added and this total score is identified in the Total Points axis. The predicted hourly urinary output can then be estimated in the UO8 mL/Kg h axis, also with a straightedge. This operation is considerably simplified with the use of a caliper. ESRD etiology: r, renal; s, systemic; u, urologic; a, adpkd; i, undetermined; AR, occurrence of acute cellular rejection within one week of transplantation; Cr1/0, ratio between plasma creatinine at postoperative day 1 and 0.
Figure 4
Figure 4. Nomogram to predict UO8.
In order to obtain the predicted hourly urinary output in mL/Kg, the user identifies each predictors’ values in their respective axes and uses a straightedge to approximate its score in the Points axis. All predictors values are added and this total score is identified in the Total Points axis. The predicted hourly urinary output can then be estimated in the UO8 mL/Kg h axis, also with a straightedge. This operation is considerably simplified with the use of a caliper. ESRD etiology: r, renal; s, systemic; u, urologic; a, adpkd; i, undetermined; AR, occurrence of acute cellular rejection within one week of transplantation; Cr1/0, ratio between plasma creatinine at postoperative day 1 and 0.
Supplemental Figure 1
Supplemental Figure 1. Calibration Plot for the UO1 model.
Supplemental Figure 2
Supplemental Figure 2. Calibration Plot for the UO8 model.
Supplemental Figure 3
Supplemental Figure 3. Equation to predict UO1.
Supplemental Figure 4
Supplemental Figure 4. Equation to predict UO8.

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References

    1. Nashan B, Abbud-Filho M, Citterio F. Prediction, prevention, and management of delayed graft function: where are we now? Clin Transplant. 2016;30:1198–1208. - PubMed
    1. Chaumont M, Racapé J, Broeders N, El Mountahi F, Massart A, Baudoux T, et al. Delayed Graft Function in Kidney Transplants: Time Evolution, Role of Acute Rejection, Risk Factors, and Impact on Patient and Graft Outcome. J Transplant. 2015;2015:163757–163757. - PMC - PubMed
    1. Ojo AO, Wolfe RA, Held PJ, Port FK, Schmouder RL. Delayed graft function: risk factors and implications for renal allograft survival. Transplantation. 1997;63:968–974. - PubMed
    1. Siedlecki A, Irish W, Brennan DC. Delayed graft function in the kidney transplant. Am J Transplant. 2011;11:2279–2296. - PMC - PubMed
    1. Redfield RR, Scalea JR, Zens TJ, Muth B, Kaufman DB, Djamali A, et al. Predictors and outcomes of delayed graft function after living-donor kidney transplantation. Transpl Int. 2016;29:81–87. - PubMed
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