Peritoneal dialysis in very low and extremely low birthweight infants: A pooled analysis

BACKGROUND

Peritoneal dialysis (PD) represents an important therapeutic option in neonatal acute kidney injury (AKI), although evidence regarding its effects in preterm neonates remains unclear. The present study aims to evaluate the feasibility of PD in very low birthweight (VLBW) and extremely low birthweight (ELBW) infants and clarify the association of catheter choice with clinical outcomes.

METHODS

Medline, Scopus, Web of Science, Clinicaltrials.gov and CENTRAL databases were systematically searched from inception to 15 January 2021. Studies reporting individual participant data of VLBW and ELBW infants treated with PD were selected.

RESULTS

Overall, 20 studies were included comprising 101 patients. Catheter-related complications were significantly more frequent among ELBW infants (odds ratio: 5.18, 95% confidence intervals (CI): 1.23-29.09). After inverse probability treatment weighting, compared to drainage catheters, death risk was significantly lower with the use of PD (hazard ratio: 0.42, 95% CI: 0.19-0.90) but not vascular catheters (hazard ratio: 0.58, 95% CI: 0.28-1.20). Similarly, kidney function loss was significantly lower only with the implementation of PD catheters (hazard ratio: 0.44, 95% CI: 0.21-0.94).

CONCLUSIONS

PD is a feasible kidney replacement therapy modality in VLBW and ELBW infants with AKI. The use of drainage catheters may be linked to significantly worse kidney recovery and overall survival rates, compared to PD catheters. Future cohorts should confirm the most appropriate catheter type and contribute to the standardisation of PD procedures.

Experimental models in peritoneal dialysis (Review)

Peritoneal dialysis (PD) is one of the most commonly used dialysis methods and plays an important role in maintaining the quality of life of patients with end-stage renal disease. However, long-term PD treatment is associated with adverse effects on the structure and function of peritoneal tissue, which may lead to peritoneal ultrafiltration failure, resulting in dialysis failure and eventually PD withdrawal. In order to prevent the occurrence of these effects, the important issues that need to be tackled are improvement of ultrafiltration, protection of peritoneal function and extension of dialysis time. In basic PD research, a reasonable experimental model is key to the smooth progress of experiments. A good PD model should not only simulate the process of human PD as accurately as possible, but also help researchers to understand the evolution process and pathogenesis of various complications related to PD treatment. To better promote the clinical application of PD technology, the present review will summarize and evaluate the in vivo PD experimental models available, thus providing a reference for relevant PD research.

Adequacy of Peritoneal Dialysis in Children: Consider the Membrane for Optimal Prescription

The peritoneal dialysis (PD) prescription should be adequate before being optimal. The peritoneal membrane is a dynamic dialyzer: the surface area and the vascular area both have recruitment capacity.

At bedside, prescription is based mainly on tolerance of the prescribed fill volume, and therefore a too-small fill volume is often prescribed. A too-small fill volume may lead to a hyperpermeable exchange, with potentially enhanced morbidity—or even mortality—risks. Better understanding of the peritoneal membrane as a dynamic dialysis surface area allows for an individually adapted prescription, which is especially suitable for children on automated PD.

Fill volume should be scaled for body surface area (mL/m2) and, to avoid a hyperpermeable exchange, for a not-too-small amount. Fill volume enhancement should be conducted under clinical control and is best determined by intraperitoneal pressure measurement in centimeters of H2O. In children 2 years of age and older, a peak fill volume of 1400 – 1500 mL/m2 can be prescribed in terms of tolerance, efficiency, and peritoneal membrane recruitment.

Dwell times should be determined individually with respect to two opposing parameters:

• Short dwell times provide adequate small-solute clearance and maintain the crystalloid osmotic gradient (and, thereby, the ultrafiltration capacity).

• Long dwell times enhance phosphate clearance, but can lead to dialysate reabsorption.

The new PD fluids (that is, those free of glucose degradation products, with a neutral pH, and not exclusively lactate-buffered) appear to be the best choice both in terms of membrane recruitment and of preservation of peritoneal vascular hyperperfusion.

Impact of fill volume on ultrafiltration with icodextrin in children on chronic peritoneal dialysis

BACKGROUND

Icodextrin is a solution of glucose polymers developed to provide sustained ultrafiltration over an extended dwell. Our aim was to determine whether or not fill volume with icodextrin contributes to the ability to achieve ultrafiltration in children.

METHODS

The charts of all children on chronic peritoneal dialysis between January 2000 and July 2014 were screened for the use of an icodextrin day dwell. Data were extracted from the electronic chart and the HomeChoice™ Pro card and corrected for body surface area (BSA).

RESULTS

Fifty children had an icodextrin day dwell. A linear correlation was found between the daytime fill volume and net ultrafiltration (p < 0.001). More ultrafiltration was achieved with a fill volume above 550 ml/m(2) BSA (107 ± 75 ml/m(2) BSA) than with smaller fill volumes (-8 ± 99 ml; p = 0.004). Ultrafiltration was achieved in 88 % of children with a fill volume above 550 ml/m(2) BSA versus only 44 % of patients with a smaller fill volume (p = 0.001). Icodextrin was well tolerated.

CONCLUSIONS

Our observations reveal that the larger the fill volume the higher the likelihood of achieving ultrafiltration with icodextrin and suggest that a minimum day dwell volume of 550 ml/m(2) BSA seems to facilitate ultrafiltration in children. To our knowledge this is the largest study addressing ultrafiltration with icodextrin in children.

Intraperitoneal pressure and intra-abdominal pressure: are they the same?

BACKGROUND

In peritoneal dialysis (PD), a standard therapy for patients with end-stage renal disease (ESRD), the effects of using the peritoneum as an exchange membrane and of dialysate dwelling within the peritoneal cavity creates some mechanical changes, including an increase in intraperitoneal pressure (IPP) that might lead to intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS). The diagnosis of IAH and ACS depend on intra-abdominal measurement of IAP by an indirect technique. There is no clear distinction between IPP and intra-abdominal pressure (IAP). Our objective in this study was to find if there is real difference between IPP and IAP.

METHODS

This study was conducted at the PD unit of King Fahd Hospital of the University, Al-Khobar, between July 2008 and January 2009. To be included, patients had to have known ESRD for at least 5 years, to be 18 years of age or older at enrollment, with stable body weight and blood pressure, and with no clinical signs of overhydration. Patients with congestive heart failure III and IV (New York Heart Association criteria) and severe pulmonary disease, psychiatric illnesses, neurogenic bladder, known history of peritonitis, or medical or surgical abdominal intervention in the preceding 3 months were excluded. We measured IAP by the direct technique through the peritoneal catheter and by an indirect technique using an intravesical catheter.

RESULTS

The 25 patients who met the inclusion criteria included 13 men and 12 women, with a mean age of 53 ± 2 years (range: 18 - 76 years). The predominant causes of ESRD were diabetes mellitus and glomerulonephritis. Mean IPP in the dry state (supine) was 9.49 ± 5 mmHg, and mean IAP was 9.4 ± 5.4 mmHg (p = 0.9). In the dry state (erect), the mean IPP increased to 16.9 ± 7.2 mmHg, and the mean IAP, to 16.4 ± 6.9 mmHg (p = 0.8). In the filled state (supine), mean IPP was 12.6 ± 4.7 mmHg, and mean IAP, 12.8 ± 4.8 mmHg (p = 0.88); the erect pressures were 21.4 ± 7 mmHg and 21.6 ± 6.9 mmHg respectively (p = 0.9).

CONCLUSIONS

Our findings indicate that there is no statistical difference between IPP and IAP in either the erect or the supine position.