What is the fluid plan for a 10 kg infant with severe isotonic dehydration?

Answer 1

Normally in the first 1 to 2 hours you administer 1 - 2 % of the body weight or 10 - 20 mL / kg. If the dehydration is so severe that the infant is hypotensive, you would push this to 3 - 5% BW or 30 - 50 mL/kg. Replacement fluid would be normal saline in either case. If signs of shock are still present, a second bolus could be administered in the next two hours. Plasmalyte could be substituted for NS.

For the next 8 hours you would give 1/2 maintenance - or (100 mL/ kg) ÷ 3 plus replacement of 1/2 of the deficit. In infants, severe dehydration is defined as 15% of body weight, so the patient's deficit is 1.5 kg. So you would give 333 + 75 = 420 mL (rounded off) over the next eight hours. Replacement fluid would be 0.5 NS with added potassium at 20 mEq/L.

Check urine output, osmolality and electrolytes and blood gases if appropriate, in six hours and adjust fluids accordingly. Give maintenance and residual deficit over next 8 hours, including potassium at 20 mEq/L

Answer 2

You've left out some important details. If you're treating a kid with cholera in Bangladesh, you may have no resources other than WHO electrolyte packets mixed in the same water that caused the problem to begin with. If you're treating a toddler in the US with rotavirus and less-than-talented parents, you can get out your Harriet Lane and your calculator, but close enough for government work is two or three 200 ml saline boluses IV or IO to restore good circulation and urine output followed by a more leisurely continuation of rehydration with oral hydration solution and/or IV and you can be pretty crude, using something like D5 1/2 NS + 20 meq/liter KCl at 40-50 ml/hr for the next few hours, and that may not be exactly what your calculations say is ideal, but it's close enough to do the job safely and effectively assuming normal renal function and no other problems (but I did have a kid that needed steroids for a congenital hormonal problem that I won't specify on this site, just yesterday). Once you get those orders written and things have stabilized out some, you can go back and fine-tune your rate and electrolyte combinations. Most often, by then, the kid's tolerating oral rehydration, anyway, so you're OK without having to make a real formal plan.