Hemodynamic changes in hypernatremic dehydration in the mini-pig.

Hypernatremic dehydration with metabolic acidosis and azotemia was experimentally induced in the mini-pig by feeding a hypertonic NaCl and NH4Cl solution wit nasogastric tube. After a loss of 19% of initial body weight within 32 hours, the following hemodynamic changes were observed: the heart rate rose, the arterial blood pressure was maintained, but cardiac output fell to 80% of its initial value. There was a redistribution of this lowered cardiac output with unchanged blood flow to heart, brain, adrenals and skeletal muscle. The flow to these vital organs was diverted to selective vasoconstriction of spleen, pancreas, gastrointestinal tract and kidneys. Quantitatively the contribution from the latter two organs was the most important.