Sodium Balance and the Dysnatremias

Tonicity of oral rehydration solutions affects water, mineral and acid–base balance in calves with naturally occurring diarrhoea

“…Serum urea concentrations and urine urea content were lower in calves fed ORS, indicating that all three ORS were able to rehydrate animals to some extent, thus allowing for urea excretion through urine (Higgins, 2016). Control calves had lower urine water and Na + losses, which may be attributed to an increased secretion of aldosterone and antidiuretic hormone resulting in water and Na + retention to mitigate dehydration (Byers et al, 2014). The higher mineral excretion in urine, as well as the lower urine volume in HYPER calves, led to a 30% increase in urine osmolality when compared to other groups.…”

“…Oral rehydration solutions for diarrhoeic animals usually contain high Na + concentrations (>70 mM) to compensate for diarrhoeal faecal Na + losses and, thus, to replenish the extracellular fluid volume (Smith & Berchtold, 2014). Serum Na + remained constant in calves receiving ORS, while CON calves developed hyponatremia (serum Na + <130 mM; Byers, Lear, & Van Metre, 2014). The lower serum Na + in CON calves was the consequence of faecal Na + losses exceeding the daily Na + intake.…”

Clinical signs, profound acidemia, hypoglycemia, and hypernatremia are predictive of mortality in 1,400 critically ill neonatal calves with diarrhea

“…This finding was consistent with calves in the 10 th decile of plasma sodium concentrations ( c Na + > 151.1 mmol/L) having an observed mortality rate of 51% ( Fig 2 ). In general, hypernatremia can result from excessive free water loss resulting in hypertonic dehydration (which is unusual in diarrheic calves), administration of oral or parenteral fluids with a high sodium content to animals with limited or no access to free water, ingestion of sodium-containing salts without ingesting an adequate volume of water, or combinations of these factors [ 72 ]. Cases of hypernatremia and salt intoxications in neonatal diarrheic calves have also been reported previously and were mostly attributed to mixing errors of oral electrolyte solutions [ 73 – 75 ].…”

“…The latter homeostatic response complicates the clinical management of hypernatremic animals, as it predisposes to the development of cerebral edema by intracellular fluid shifts if intravenous fluid therapy is necessary as it was in most of the calves in the study reported here. Early clinical signs of hypernatremia in calves are severe depression and lethargy [ 73 ], and tremors, seizures, opisthotonus and coma in more advanced stages, causing a clinical picture which is usually called salt poisoning or water intoxication [ 72 , 80 ]. In the present study the large majority of hypernatremic calves that did not survive to discharge were euthanized for reasons of a massive deterioration of the general condition, ongoing depression or dramatic neurological symptoms indicating that hypernatremia was indeed a direct cause for a negative outcome.…”

Short communication: Hypernatremia in diarrheic calves associated with oral electrolyte administration in water and milk replacer in absence of access to water

“…Administration of sugar and mineral mix in whole milk (WM) or milk replacer (MR) has become a common practice in past decades Short communication: Hypernatremia in diarrheic calves associated with oral electrolyte administration in water and milk replacer in absence of access to water because it allows a substantial reduction of labor associated with the treatment of diarrheic calves (Bachmann et al, 2012). However, one should consider that WM and especially MR already contain high amounts of lactose (140-230 mmol/L) and Na + (17-80 mmol/L; Byers et al, 2014). The high Na + concentrations in MR are due to the high Na + content of whey (up to 2%) used to formulate MR (Byers et al, 2014) and the high percentage of solids per liter of solution in MR (up to 20%).…”