This document discusses hypernatremia (high sodium levels) and its treatment using peritoneal dialysis (PD). It provides details on: 1) An infant who developed hypernatremia after heart surgery and was treated with various PD prescriptions using dialysate with different sodium concentrations and dwell times to gradually reduce the sodium level. 2) How rapid cycling with hypertonic dialysis solutions can cause hypernatremia due to enhanced free water clearance, and how extending dwell time or using hypotonic fluids can help if it develops. 3) How the sieving coefficient for ultrafiltrate sodium concentration is about 10% during the first hour and 60% after a 6-hour dwell,

1. HyperNa and PD
(Salt toxicity)
Hooman N
Professor of Pediatric nephrology
IUMS
2020

2. Slat toxicity definition
• Single massive exposure to salt (NaCl) over a
short period of time ( minutes to hours )

3. Lethal dose
• Children <5 teaspoon
• Adult <4 tablespoon

6. Survival

9. • Peritoneal dialysis involves
– diffusive
– convective transports
– Osmosis
through the highly vascularized peritoneal
membrane

13. 4m infant > heart surgery> Multiorgan Failure > fluid overload>PD
D1.5%, Na140meq/L, DV=60ml, 16 cycles, DT=60 min

14. 4m infant > heart surgery> Multiorgan Failure > fluid overload>PD
D1.5%, Na140meq/L, DV=80ml, 6 cycles, DT=40 min

15. 4m infant > heart surgery> Multiorgan Failure > fluid overload>PD
D1.5%, Na130meq/L, DV=80ml, 11 cycles, DT=40 min

16. 4m infant > heart surgery> Multiorgan Failure > fluid overload>PD
D 5%, Na70meq/L, DV=80ml, 10 cycles, DT=120 min

17. 4m infant > heart surgery> Multiorgan Failure > fluid overload>PD
D 4.25%, Na132meq/L, DV=80ml, 10 cycles, DT=120 min

18. • In cases of severe hyperNa, add concentrated
NaCl to increase Na to within about 15 mmol
of patient’s sodium to allow a gradual
reduction in the serum sodium.
Peritoneal Dialysis International, Vol. 34, pp. 494–517

19. • [DNa ] =132 – 134 mmol/L.
• with acute PD, rapid cycling with hypertonic dialysis
solutions to promote UF can result in hyperNa as a
result of enhanced free water clearance secondary
to sodium sieving and transport of water through
aquaporin channels
Peritoneal Dialysis International, Vol. 34, pp. 494–517

20. • The removal of free water is greatest during the initial 30 – 60
minutes of each exchange.
• If hyperNa develops, consideration should be given to
extending the dwell time if solute clearance allows or
lowering the concentration of glucose in the dialysis solution.
• If rapid cycling is needed for solute removal and fluid balance
is neutral or negative, a hypotonic fluid such as 0.45% saline
can be infused intravenously to match the net UF from PD.
Peritoneal Dialysis International, Vol. 34, pp. 494–517

21. PD prescription
During the 1st h of a dialysate exchange the ultrafiltrate sieving coefficient is
approximately 0.1, while following a 6-h dialysate exchange it is 0.6
This corresponds to a dialysate ultrafiltrate sodium concentration of 10% and 60% of
the serum sodium concentration, respectively.

24. Take home message

25. questions