dehydration + fluid management

Question 1

Physical Exam Findings

Answer 1

tachycardia
hypotension (severe, >10% BW)
low urine output
dry mucous membranes
sunken fontalle
sunken eyes
decreased skin turgor/tenting
thirst
decreased LOC

note: mild dehydration (<5% body weight) just slight tachy/urine/thirst/MM

Question 2

Pure Water Loss Causes

Answer 2

insensible - skin/resp - accounted for in 421 rule (higher /w fever)

urine loss in diabetes insipidus, urea osmotic diuresis (TPN)

Question 3

Hypotonic Fluid Loss Causes (Na <130)

Answer 3

Sweat
vomit
diarrhea if osmotic laxative
urine if glucose/mannitol
urine with most diuretics

Question 4

what fluid to replace hypotonic losses with?

Answer 4

1/2 NS

Question 5

Isotonic fluid losses (Na 130-150) causes

Answer 5

burns
non-osmotic diarrhea
ileus
3rd spacing
urine if thiazide diuretics

Question 6

What to replace isotonic losses with?

Answer 6

NS

Question 7

Maintenance Fluids for Neonates

Answer 7

kidneys immature, therefore can’t concentrate fluids

choose fluid amount based on TFI (ml/kg/d)

DOL1: no lytes, D10W or lyte free TPN
DOL2: D10 in 1/4NS or TPN for NICU, D10 in 1/2 NS for wards

TFI starts at 80 for term and 60 for premies, increase by 20 per day until reach 160

Question 8

Fluid Types

Answer 8

NS - 0.9% NaCl (na is 154)
1/2 NS - 0.45 NaCL 
D5W - 5% dextrose in water 
D5NS - 5% dextrose in NS
1/4 NS - 0.2%NaCl

Question 9

Choice of maintenance Fluids in Infants + Kids

Answer 9

• generally D5NS, add 20meq/L K+ after 1st void
  (for resuscitation boluses, just use NS)
• check Cr lytes before starting
• if on >50% maintenance, daily lytes
• Na < 145, use NS
• Na 145-154 use 1/2NS
• Na >154 risk of cerebral edema /w rapid correction.. replace fluid slowly /w concentration based on rate of correction

Question 10

4-2-1 Rule

Answer 10

maintenance fluids - ml per hour

4 ml/kg/hour for first 10kg
2 for next 10 kg
1 for remaining kg

Question 11

Dehydration Treatment

Answer 11

Rehydrate - use ORS if possible

• IV bolus to stabilize, then add rest of deficit back over next 24hrs
• replace ongoing losses 1:1 (PO or IV), measure ins + outs, adjust q4h

Bolus depending on dehydration:

• mild 50ml/kg ORS over 4hr
• mod: 100ml/kg ORS over 4hr
• severe: 20ml/kg IV bolus in 20min, repeat 1-2x PRN, then continue rehydration when stable

Question 12

Dehydration Treatment

Answer 12

Rehydrate - use ORS if possible

• IV bolus to stabilize, then add rest of deficit back over next 24hrs (add to maintenace
• replace ongoing losses 1:1 (PO or IV), measure ins + outs, adjust q4h

Bolus depending on dehydration:

• mild 50ml/kg ORS over 4hr
• mod: 100ml/kg ORS over 4hr
• severe: 20ml/kg IV bolus in 20min, repeat 1-2x PRN, then continue rehydration when stable