Vieux Momeme Mokoli1,2*, Ernest Kiswaya Sumaili1, François Bompeka Lepira1, Jean Robert Rissassy Makulo1,2,
Justine Busanga Bukabau1, Patrick Parmba osa Izeidi1, Jeannine Losa Luse3, Stéphane Kalambay Mukendi3,
Désiré Kulimba Mashinda4 and Nazaire Mangani Nseka1
Abstract
Background:
Despite the multiple benefits of maintaining residual urine volume (RUV) in hemodialysis (HD), there
is limited data from Sub-Saharan Africa. The aim of this study was to assess the impact of RUV decline on the
survival of HD patients.
Methods: In a retrospective cohort study, 250 consecutive chronic HD patients (mean age 52.5 years; 68.8% male,
median HD duration 6 months) from two hospitals in the city of Kinshasa were studied, between January 2007 and
July 2013. The primary outcome was lost RUV. Preserved or lost RUV was defined as decline RUV < 25 (median
decline) or ≥ 25 ml/day/month, respectively. The second endpoint was survival (time-to death). Survival curves were
built using the Kaplan-Meier methods. We used Log-rank test to compare survival curves. Predictors of mortality
were assessed by Cox proportional hazards regression models.
Results: The cumulative incidence of patients with RUV decline was 52, 4%. The median (IQR) decline in RUV was
25 (20.8–33.3) ml/day/month in the population studied, 56.7 (43.3–116.7) in patients deceased versus 12.9 (8.3–16.7)
in survivor patients (p < 0.001). Overall mortality was 78 per 1000 patient years (17 per 1000 in preserved vs 61 per
1000 lost RUV). Forty six patients (18.4%) died from withdrawal of HD due to financial constraints. The Median
survival was 17 months in the whole group while, a significant difference was shown between lost (10 months,
n = 119) vs preserved RUV group (30 months, n = 131; p = 0001). Multivariate Cox proportional hazards models
showed that, decreased RUV (adjusted HR 5.35, 95% CI [2.73–10.51], p < 0.001), financial status (aHR 2.23, [1.11–4.46],
p = 0.024), hypervolemia (a HR 2.00, [1.17–3.40], p = 0.011), lacking ACEI (aHR 2.48, [1.40–4.40], p = 0.002) or beta
blocker use (aHR 4.04, [1.42–11.54], p = 0.009), central venous catheter (aHR 6.26, [1.71–22.95], p = 0.006), serum
albumin (aHR 0.93, [0.89–0.96], p < 0.001) and hemoglobin (aHR 0.73, [0.63–0.84], p < 0.001) had emerged as the
independent predictors of all-cause mortality.
Conclusion: More than half of HD patients in this cohort study experienced fast RUV decline which contributed
substantially to increase mortality, highlighting the need for its prevention and management.
Keywords: Residual urine volume decline, Chronic hemodialysis, Survival, Kinshasa
Mokoli et al. BMC Nephrology (2016) 17:182
DOI 10.1186/s12882-016-0401-9
