Isotonic maintenance fluid: Practice Gap discussion at Update Course 2018

Iatrogenic hyponatremia is one of the biggest problems in hospitals, related to ADH physiology and the use of hypotonic fluids rather than normal saline.

Children become hyponatremic because they are given half normal saline, and the data on this are clear.

The correct maintenance fluid for a 15-year-old post-colectomy patient is D5 normal saline with 20 milliequivalents of potassium.

The American Academy of Pediatrics is coming out with a consensus statement on isotonic maintenance fluids (anticipated as of March).

Hospitalized children develop hyponatremia because they receive less than isotonic (hypotonic) solutions, leading to cerebral edema and other complications.

The traditional teaching was to resuscitate with isotonic fluid and then convert to hypotonic maintenance fluids; the new practice is to keep patients on isotonic fluid to prevent hyponatremia.

At ABSA, 48% of respondents correctly identified isotonic fluid as the answer, which the speakers considered a high number given the radical change from traditional teaching.

Hypotonic fluids were originally developed based on theoretical calculations of sodium and chloride losses by a scientist approximately 100 years ago, not on evidence from real patients.

Newborn babies are different because their kidney function is immature when first born, so the amount of electrolytes given changes over the first couple of days of life.

Term newborns on the first day of life should receive D10W (dextrose 10% in water) with no saline.

In adult critical care literature, practice is shifting from normal saline to lactated Ringer's as the normal isotonic solution, and the same shift is expected to occur in pediatrics.

Lactated Ringer's is a more physiologic isotonic solution than normal saline.

There is not yet literature in children supporting the use of D5 lactated Ringer's, but it is anticipated.