Untersuchung der Ultrafiltrationskapazität bei der Peritonealdialyse von Früh- und Reifgeborenen

The aim of this retrospective study is to analyse the capacity of ultrafiltration and the peritoneal characteristics of preterm- and term-born infants on chronic peritoneal dialysis. Due to deficient available data and the low incidence of diseases leading to the necessity of a treatment with peritoneal dialysis in infants, there is still not much known about peritoneal characteristics in this population. We describe the ultrafiltration of preterm- and term-born infants on chronic peritoneal dialysis. Therefore, we quantified the achieved ultrafiltration volume, pointed out parameters that exert influence on ultrafiltration and observed the dynamic of ultrafiltration during the treatment on dialysis. Furthermore, we assessed the adequacy of peritoneal dialysis by reflecting as main criteria the development of weight gain and the fluid balance. 13 of our patients that were treated with peritoneal dialysis in the paediatric clinic of Philipps university Marburg were included in this study. The period of observation lasted from 23 to 67 days. The ultrafiltration capacity was determined retrospectively by analysing the records of the performed CAPD in terms of total ultrafiltration volume, fill volume, dwell time and dialysate glucose concentration. In addition, we registered the daily weight measurements of intensive care unit and the aimed dry weights determined by the treating physician. We identified a possible fluid overload respectively a fluid loss regarding the difference of measured weight and determined dry weight. The evaluation of this data provided a mean daily ultrafiltration of 164 ml and accordingly 2,5 ml/kg body weight/h. There was a positive correlation of fill volume (r = 0,7173) and dialysate glucose concentration (r = 0,3564) on ultrafiltration per kilogram bodyweight per hour as well as of dwell time (r = 0,6007) on absolute ultrafiltration. Bodyweight and fill volume showed a positive correlation (r = 0,8852). Despite there was an increase of fill volume per kilogram bodyweight (r = 0,7249) during the treatment, a continuous decrease of ultrafiltration per fill volume (r = -0,7662) and per glucose exposition (r = -0,8284) could be observed. On average all patients had a fluid overload of 226 g respectively 10 %. Until day 34 of our observation, there was a continuous decrease of fluid overload, in the following days there was a slight increase of fluid overload. Even though an averaged weight gain of 829 g during the observation period could be achieved, there occurred a decrease of the mean weight percentile of about -13,5 percentiles and a mean decrease of the Z-score of about -0,53. This study constitutes one of the first trials to determine the amount of ultrafiltration of preterm- and term-born infants on chronic peritoneal dialysis. Referring to the low fill volumes used especially in the beginning of dialysis treatment, a relatively high ultrafiltration could be achieved. Although there was an increase of fill volume referring to body weight during treatment, ultrafiltration referring to fill volume decreased. Equally the ratio of ultrafiltration and glucose exposition decreased. Despite the reduced ultrafiltration, fluid overload attains a balanced status until day 34. This study also contains an evaluation of adequacy of peritoneal dialysis. Even though an improvement of the fluid overload during dialysis treatment could be observed, there was no sufficient weight gain of our patients. Deficient outcomes in growth and prosperity must be considered. To gain further insights into the development of ultrafiltration and the peritoneal membrane during the postnatal period, more research is needed. Some possibilities would be a prospective study, a higher quantity of patients and a control group in a different age. Further research could enable the understanding for the cause of changes in ultrafiltration and offer possibilities to optimize dialysis adequacy for postnatal peritoneal dialysis.