How do you manage fluids in the ELBW - 500g infant?

We start at 100 ml/kg/d and increase by ~20 ml/kg daily. 

Despite plastic wrap in DR, humidified incubators, etc we often have significant hypernatremia usually by 24 hours, sometimes > 150, sometimes > 160. 

Is this a sodium problem or a water problem or (probably) both?

These little guys have lots of transepidermal water loss especially in the first 2 days. They also get Na Acetate via UAC giving sometimes 1.5-2 mEq/kg/d of Na in that first day when the kidneys (from what I read) can excrete free water but cannot filter an excess sodium load well. And some lit suggests retention of birth weight (or not having the physiologic 10-15% wt loss in ELBW) is associated with BPD, PDA, etc. 

When would you give normal saline bolus for hypernatremia considering that the kidneys may not be able to excrete excess Na load? Or would you just continue to increase free water via non-Na fluids to replace the insensible losses and restore intravascular volume. How high would you go with total fluids? 180-200 ml/kg/d in the first 2-3 days of life? Higher? Any experience with sterile water drip via orogastric tube for ELBW with hypernatremia?

 

We usually do the same as what you mentioned, increase 20% fluids ad check Na frequently say Q6hrly. Once Normalize reduce TFI. Yes we replace free water with Na free solution but give maintenance Na which Baby any ways get from UAC heparin Saline ( 0.45% saline) and put 2mmol/Kg in TPN as acetate to tackle acidosis. We can go up as much as 200ml/kg/day and maximum  Humidity to 95%. Never give saline bolus and NG drip with sterile water.  I hope it helps

We also start with 100 ml/kg/d with a sodium (and potassium) free tpn. We do liquid balancing every 8 hours with the goal of plus 10 ml/kg, replacing liquid lost by urine and stool. As replacement with use Ringer Acetat solution.

We start adding sodium to the tpn as soon as the levels drop and accept sodium levels of 150 mmol/l  without any intervention.

I don't have the feeling that we had any problems with too high sodium counts in preterms. 

 

We also start with 100 ml/kg/d. Unfortunately we have only sodium chloride and in ELBW septic premies very often we have high Na and hyper chloride metabolic acidosis. It’s interesting for us to know does it possible to provide UAC with other solutions except NS?

we are starting with 80 ml/kg/day with sodium monitoring 

we are not adding sodium in the first 24 hours 

their juxta glomerular apparatus is very sensetive they can not deal with sodium 

even some literatures is saying no need to add sodium in first few days 

 

Certainly the reason for hypernatremia during the first days of life in these infant is excess of free water loss (transpepidermal), so besides plastic bags and high humidity 100 ml/kg/d free water (dextrose) is a reasonable starting point. Additional infusion of sodium,however, often cannot be handled by these infants. Therefore we have changed our infusion policy for umbilical artery catheters (formerly with isotonic sodium chloride at 0.5 ml/kg which sums up to 3.4 mmol sodium/kg/d in a 500 g premie) and now use a isotonic sodium-free mixture of sterile water and amino acids 10% (7 ml Aminovenös infant 10% + 13 ml sterile water + 12 U Heparin) which was published by a group from Kansas (Jodi Jackson et al, Pediatrics 2004;114:377) and was shown to not increase hypososmotic hemolysis. Since we have introduced this regimen we have had only few tiny preterms with significant hypernatremia during the first week of life.

We start 10%D/W for 1st 24 hrs with 100ml/kg/day. Never do electrolytes or any other investigation on very 1st day except cbc. 

We do particular labs in frst 24 hrs if need.