Urine output and acid/base imbalance?


Hello all...

Just trying to understand the rationale behind a doctors decision on one of my patients. I find acid/base imbalance quite confusing sometimes & this issue relates to that.

So, my baby’s blood gas had a bicarb of 16, and a base excess of -9. The doctor came by and asked me how the baby’s urine output was. It was actually very high (15mls/kg/hr). He said that was what he suspected, and then ordered a normal saline bolus.

What is the correlation between urine output and acidosis? How did he know my urine output would be high? And I’m assuming he ordered the bolus to re-hydrate the baby due to the diuresis, correct?

Also, can someone explain to me exactly what a base excess is telling us? This is the first hospital I’ve worked at where we closely monitor that value.

Id appreciate any input!! Thanks.

Specializes in in primary care pediatrics and NICU. Has 32 years experience.

I know this is a late reply but... 

Sick babies (mostly preemies) are unable to concentrate their urine well. The kidneys are immature. Thus they pee out all their Bicarb, instead of reabsorption in the tubules, leading to metabolic acidosis (excess of base and low pH = unbalanced).  The sodium chloride will buffer the electrolyte imbalance and restore some volume to the kidneys. I recommend taking the STABLE course or borrowing the book from your hospital library. Good luck!  : )