Abstract: This review update included 42 eligible studies (3262 participants), including six new studies (543 participants). Overall, 29 studies (1971 participants) compared neutral pH, low GDP PD solution with conventional PD solution, and 13 studies (1291 participants) compared icodextrin with conventional PD solution. Risk of bias was assessed as high for sequence generation in three studies, allocation concealment in three studies, attrition bias in 21 studies, and selective outcome reporting bias in 16 studies. Neutral pH, low GDP versus conventional glucose PD solution Use of neutral pH, low GDP PD solutions improved residual renal function (RRF) preservation (15 studies, 835 participants: SMD 0.19, 95% CI 0.05 to 0.33; high certainty evidence). This approximated to a mean difference in glomerular filtration rate of 0.54 mL/min/1.73 m2 (95% CI 0.14 to 0.93). Better preservation of RRF was evident at all follow-up durations with progressively greater preservation observed with increasing follow up duration. Neutral pH, low GDP PD solution use also improved residual urine volume preservation (11 studies, 791 participants: MD 114.37 mL/day, 95% CI 47.09 to 181.65; high certainty evidence). In low certainty evidence, neutral pH, low GDP solutions may make little or no difference to 4-hour peritoneal ultrafiltration (9 studies, 414 participants: SMD -0.42, 95% CI -0.74 to -0.10) which approximated to a mean difference in peritoneal ultrafiltration of 69.72 mL (16.60 to 122.00 mL) lower, and may increase dialysate:plasma creatinine ratio (10 studies, 746 participants: MD 0.01, 95% CI 0.00 to 0.03), technique failure or death compared with conventional PD solutions. It is uncertain whether neutral pH, low GDP PD solution use led to any differences in peritonitis occurrence, hospitalisation, adverse events (6 studies, 519 participants) or inflow pain (1 study, 58 participants: RR 0.51, 95% CI 0.24 to 1.08). Glucose polymer (icodextrin) versus conventional glucose PD solution In moderate certainty evidence, icodextrin probably reduced episodes of uncontrolled fluid overload (2 studies, 100 participants: RR 0.30, 95% CI 0.15 to 0.59) and augmented peritoneal ultrafiltration (4 studies, 102 participants: MD 448.54 mL/d, 95% CI 289.28 to 607.80) without compromising RRF (4 studies, 114 participants: SMD 0.12, 95% CI -0.26 to 0.49; low certainty evidence) which approximated to a mean creatinine clearance of 0.30 mL/min/1.73m2 higher (0.65 lower to 1.23 higher) or urine output (3 studies, 69 participants: MD -88.88 mL/d, 95% CI -356.88 to 179.12; low certainty evidence). It is uncertain whether icodextrin use led to any differences in adverse events (5 studies, 816 participants) technique failure or death. This updated review strengthens evidence that neutral pH, low GDP PD solution improves RRF and urine volume preservation with high certainty. These effects may be related to increased peritoneal solute transport and reduced peritoneal ultrafiltration, although the evidence for these outcomes is of low certainty due to significant heterogeneity and suboptimal methodological quality. Icodextrin prescription increased peritoneal ultrafiltration and mitigated uncontrolled fluid overload with moderate certainty. The effects of either neutral pH, low GDP solution or icodextrin on peritonitis, technique survival and patient survival remain uncertain and require further high quality, adequately powered RCTs.

Plain-language summary: We identified 42 studies (3262 participants) examining the effects of these solutions on patient outcomes. When compared to conventional peritoneal dialysis solutions, we found that neutral pH, low glucose breakdown product peritoneal dialysis solutions resulted in better preservation of a patient's own kidney function including urine output. Patients who received non-glucose based (icodextrin) peritoneal dialysis solutions achieved greater fluid removal with their dialysis and were 70% less likely to experience uncontrolled episodes of fluid overload. No significant harms were identified with any of the biocompatible peritoneal dialysis solutions. Many of the studies were limited by small size, short follow-up duration, suboptimal methodological quality, and inconsistent reporting of outcomes. Consequently, the effects of biocompatible peritoneal dialysis solutions on the length of time that a patient is able to either remain on peritoneal dialysis or stay alive are uncertain. Compared with peritoneal dialysis patients treated with conventional peritoneal dialysis solutions, those treated with biocompatible solutions experience important benefits including better preservation of their own kidney function and urine volume with neutral pH, low glucose breakdown product peritoneal dialysis solutions and more effective prevention of fluid overload due to increased dialysis-related fluid removal with icodextrin. Whether these benefits help patients to stay on peritoneal dialysis longer or live longer are uncertain and require further study.