2. WHY THE INFANTS ARE MORE
VULNERABLE TO DEHYDRATION?
� Physiological inability to concentrate
urine
� Higher metabolic rate & larger
surface area
� Cant express thirst for more fluids
� Larger turnover.
3. BODY COMPOSITION
� Water is the most plentiful constituent of the
human body.
� Total body water (TBW) as a percentage of
body weight varies with age.
� During dehydration, TBW decreases and is a
smaller percentage of body weight.
� TBW has two main compartments:
1. intracellular fluid (ICF) and
2. extracellular fluid (ECF).
� In the fetus and newborn, the ECF volume is
larger than the ICF volume.
4. THE NEWBORN AND INFANT HAVE A HIGH PERCENTAGE OF BODY WEIGHT
COMPRISED OF WATER, ESPECIALLY EXTRACELLULAR FLUID WHICH IS LOST
FROM THE BODY EASILY. NOTE THE SMALL STOMACH SIZE WHICH LIMITS
THE ABILITY TO REHYDRATE QUICKLY
6. ECF AND ICF COMPOSITION
ICF (mEq/L) ECF (mEq/L)
Sodium 20 135-145
Potassium 150 3-5
Chloride ----- 98-110
Bicarbonate 10 20-25
Phosphate 110-115 5
Proteins 75 10
Key learning points
Sodium is the Principle electrolyte in ECF
Potassium is the Principle electrolyte in ICF
Osmolarity Osmolarity
=
7.
8. ADH ACTIVATION
� The plasma osmolality is tightly controlled
between 285 and 295 mOsm/kg through
regulation of water intake and urinary water
losses.
� A small increase in the plasma osmolality
stimulates thirst.
� Urinary water losses are regulated by the
secretion of antidiuretic hormone (ADH),
which increases in response to an increasing
plasma osmolality.
� ADH, by stimulating renal tubular reabsorption
of water, decreases urinary water losses.
9. SODIUM REGULATION
� Sodium is the principal extracellular cation and
is restricted to the ECF, adequate body sodium is
necessary for maintenance of intravascular
volume.
� The kidney determines sodium balance because
there is little homeostatic control of sodium
intake
� The kidney regulates sodium balance by altering
the percentage of filtered sodium that is
reabsorbed along the nephron.
� The renin-angiotensin system is an important
regulator of renal sodium reabsorption and
excretion.
11. FLUID THERAPY
Fluid therapy is used to correct body water and
electrolytes disturbance, to restore and maintain blood
volume, osmolality, pH and electrolyte composition and
to restore normal physiological function
14. WHOM TO GIVE MAINTENANCE
FLUIDS?
� Maintenance fluids are given to compensate for
ongoing losses and are required for all patients.
� Maintenance fluids are frequently given through an
intravenous line, but can also be given orally if the
patient is able to tolerate oral therapy.
� Infants who are sick & whose oral intake is uncertain
� Babies who are kept NBM for the surgery, with
respiratory distress etc.
� Neonates kept under radiant warmer.
15. GOALS OF MAINTENANCE FLUIDS
� Prevent dehydration
� Prevent electrolyte disturbance
� Prevent ketoacidosis
� Prevent protein degradation
16. MAINTENANCE FLUIDS CONSISTS OF
� Water
� Glucose
� Sodium
� Potassium
Advantages –
Simplicity, long shelf life, low cost, compatibility.
Prototypical maintenance therapy fluid doesn’t
provide calcium, phosphorus, magnesium or
bicarbonate.
17. CONCEPT OF MAINTENANCE OF WATER
� Crucial component of maintenance fluid therapy
� Maintenance water = Measurable loss of water
65% (Urine 60%, stools 5%) + Insensible of water
35% (skin & lungs)
� Fluid calculations
✔ Caloric expenditure method
✔ Holliday-Segar method
✔ Surface area method
✔ Low amount of electrolytes in fluids
18. If baby -16 kg maint of fluid= 10kg+6kg=1000ml+50ml*6kg=1300ml
If 20kg (10kg+10kg)= 1000ml+50ml*10kg = 1500ml
If 23kg (20kg+3kg) = 1500ml+20ml*3kg=1560ml
19. HOLLIDAY-SEGAR METHOD
OF ELECTROLYTE REQUIREMENTS
� Insensible water loss contains no electrolytes
� So, sodium & potassium present in the urine, stools & sweat would be the amount to be
replaced plus the sodium & potassium required for normal metabolism of the body.
3mEq of sodium Na+ in 100 ml of fluid &
2mEq of potassium K+ in 100 ml of fluid
16kg baby 10kg+6kg=1000ml+6*50ml= 1300ml – maint of fluid 3meq-100ml x-1300ml x13
maintenance of sodium 3mEq*13=39mEq /day
Maintenance of Potassium 2mEq*13=26 mEq
22kg –
Maint of fluid – 1500 ml + 2x20ml= 1540 ml
Maint of sodium 3x15.4=46.2 meq
Maint of pottai – 2x15.4=30.8 meq
9 kg – maint – 900 ml 3x9=27
Na – 3-100
X-900
x=3x900/100= 27
20. CONCEPT OF MAINTENANCE OF
GLUCOSE
� Maintenance fluids usually contains 5%
dextrose
(5 gm/100ml) providing 17 calories/ 100 ml of
fluid.
� Which is approx. 20% of the daily caloric needs.
� Prevents ketone production.
21. DEFICIT THERAPY
Fluids lost prior to medical care are termed “deficit
fluids.”
Examples:
✔ gastrointestinal illness with vomiting and
diarrhea
✔ traumatic injuries with significant blood loss
✔ inadequate intake of fluids over a period of time.
22. DEHYDRATION IS NOT A DISEASE
1) Decreased intake
2) Increased output
⚫ Insensible losses
⚫ Renal losses
⚫ GI losses
3) Translocation
⚫ Burns
⚫ Ascites
23. CAUSES OF DEHYDRATION
� Diarrhea
� Vomiting
� Gastroenteritis
� Stomatitis or
pharyngitis
� Febrile illness
� DKA
� DI
� Burns
24. DEHYDRATION
� Best predictors of at least 5% dehydration
- Prolonged capillary refill
- Abnormal skin turgor
- Abnormal cardio-respiratory pattern
25. The fluid deficit is the
percentage of dehydration multiplied by
the patient’s weight
(for a 10-kg child, 10% of 10 kg =1 L
deficit).
26. APPROACH TO PEDS DEHYDRATION
1) Initial Resuscitation
2) Determine % dehydration
3) Define the type of dehydration
4) Determine the type and rate of
rehydration fluids
5) Final considerations
27. 1. INITIAL RESUSCITATION
� ABCs
� Initial fluid bolus
� 20cc/kg of NS or Ringers
� Appropriate in all types of dehydration
� Reassess q5mins and repeat x 3
� Initial hypoglycemia
� 5cc/kg of D10W in infants
� 2cc/kg of D25W in children
� Think about Shock DDx if unresponsive to
3 attempts at NS bolus
28. APPROACH TO PEDS DEHYDRATION
1) Initial Resuscitation
2) Determine % dehydration
3) Define the type of dehydration
4) Determine the type and rate of
rehydration fluids
5) Final considerations
29. CLINICAL SIGH OF DEHYDRATION
Weight loss: (m1 before illness – m2 after illness)/m before *100%
m before illness 16kg, 14kg after illness – weight loss= (16-14)/16
=0.125*100%=12.5%
30. APPROACH TO PEDS DEHYDRATION
1) Initial Resuscitation
2) Determine % dehydration
3) Define the type of dehydration
4) Determine the type and rate of
rehydration fluids
5) Final considerations
31. 3. TYPES OF DEHYDRATION
Types of
dehydration
Sodium
mEq/L
Common
causes
Isonatremic 130-150 Secretory diarrhea
Equal losses of Na and
Water
Hyponatremic
Water shifts from ICF
to ECF
<130 Replacing with
hypotonic fluids
Hypernatremic >150 Viral gastroenteritis
Increased Na+ intake
due to incorrect formula
32. ISONATREMIC DEHYDRATION
� By far the most common
� Equal losses of Na and Water
� Na = 130-150
� No significant change between fluid
compartments
� No need to correct slowly
33. HYPERNATREMIC
DEHYDRATION
� Water loss >
sodium loss
� Na >150mmol/L
� Water shifts from ICF to ECF
� Child appears relatively less ill – looks
better than you would expect based on fluid
loss
� More intravascular volume
� Less physical signs
� Alternating between lethargy and hyperirritability
� Use 4 ml/kg of body weight for each mEq of Na+ above
145 mEq/ml as the Free water deficit= total amount of
free water needed to dilute the serum to get a normal
consentracion of Na
� Correct slowly for 48 hours
34. HYPERNATREMIC DEHYDRATION
� Physical findings
⚫ Dry doughy skin
⚫ Increased muscle tone
� Correction
⚫ Correct Na slowly
⚫ If lowered to quickly causes
� massive cerebral edema
� intractable seizures
35. HYPONATREMIC DEHYDRATION
� Sodium loss > Water loss
� Na <130mmol/L
� Water shifts from ECF to ICF
� Child appears relatively more ill
� Less intravascular volume
� More clinical signs
� Cerebral edema
� Seizure and Coma with Na <120
36. HYPONATREMIC DEHYDRATION
� Correction
⚫ Must again be performed slowly unless actively
seizing
⚫ Rapid correction of chronic hyponatremia thought to
contribute to….
Central Pontine Myelinolysis
� Fluctuating LOC
� Pseudobulbar palsy
� Quadraparesis
37. APPROACH TO PEDS DEHYDRATION
1) Initial Resuscitation
2) Determine % dehydration
3) Define the type of dehydration
4) Determine the type and rate of
rehydration fluids
5) Final considerations
39. STEP 1 - ORS- PRESCRIPTION
� As a guideline for oral rehydration, 50 mL/kg of
the ORS should be given within 4 hours to
patients with mild dehydration,
� 100 mL/kg should be given over 4 hours to
patients with moderate dehydration.
� Supplementary ORS is given to replace ongoing
losses from diarrhea or emesis.
� An additional 10 mL/kg of ORS is given for each
stool
40. ORAL REHYDRATION SOLUTION (ORS)
� Mild to moderate dehydration from diarrhea of
any cause can be treated effectively using a
simple, oral rehydration solution (ORS)
containing glucose and electrolytes
� Oral rehydration therapy has significantly
reduced the morbidity and mortality from acute
diarrhea but is underused in developed countries.
� IV therapy may still be required for patients with
severe dehydration;
⚫ patients with uncontrollable vomiting; patients
unable todrink because of extreme fatigue, stupor, or
coma; or patients with gastric or intestinal
distention.
41. STEP 2 ACUTE INTERVENTION TO ENSURE THAT
THERE IS ADEQUATE TISSUE PERFUSION
Isotonic solution - normal saline (NS) or Ringer’s lactate.
� given a fluid bolus, usually 20 mL/kg of the isotonic
solution, over about 20 minutes
� If no response after 2 boluses – plasma, blood, albumin and
consider inotropes or consider other types shocks: sepsis,
cardiac
42.
43. FLUID DEFICITE
e.g. child weighs 7 kg with 10% dehydration
7x100 ml =700 ml
e.g. child weighs 7 kg with 15% dehydration
7X150 ml = 1050 ml
� Ideally the weight before illness, e,g. weight before illness
11 kg and current 9 kg, % of dehydration
(11-9)/11 kg X 100% = 18%
� Percentage of dehydration* to body weight
10% - 100 ml per kg
15% - 150 ml per kg
44. ELECTROLYTE DEFICIT
ECF deficit (mainly Na) ICF deficite (mainly K)
< 3 days illness
80%
< 3 days illness
20%
> 3 days illness
60%
> 3 days illness
40%
45. ELECTROLYTE DEFICIT
� Na deficit
- Fluid deficit (L) x 0.6x140
- Example: 1000 mL *0.6*140= 84 mEq
Na/L
- 8.4 mEq/100 ml fluid deficit
- If deficite is 1000 ml – 84 meq/L Na
o K deficit
- Fluid deficit (L) x 0.4x150
- Example: 1000 mL *0.4*150= 60 mEq
Na/L
- 6 mEq/100 ml fluid deficit
ECF - Na ICF K
140 150
60% 40%
46. APPROACH TO PEDS DEHYDRATION
1) Initial Resuscitation
2) Determine % dehydration
3) Define the type of dehydration
4) Determine the type and rate of
rehydration fluids
5) Final considerations
47. FINAL CONSIDERATIONS
� Does and Acid-Base Deficit exist?
� Does a potassium disturbance exist?
� What is the patients renal function?
48. APPROACH TO PEDS DEHYDRATION
1) Initial Resuscitation
2) Determine % dehydration
3) Define the type of dehydration
4) Determine the type and rate of
rehydration fluids
5) Final considerations
49. CASE 1. SCENARIO
� 10 month old infant , 4 days of frequent watery stool, he is
listless in his mother’s arm
� Physical examination: dry mucus membrane, skin is
tenting, HR 160, BP 80/40 mmHG,
� Weight – 9 kG
� Weight before illness 10 kg, serum Na 138 mEq/dl.
1. ABCD + Boluses 20cc/kg – 20x9=180 ml x2
2. 10-9/10x100%= 10%
3. Isonatremic dehydr
4. Mainc of fluid 10kgx100ml=1000ml
Deficite of fluid = 10kgx100ml=1000ml
Maint Na – 3meqx10=30 meq/l
Deficite Na – 8.4meqx10=84mq/l
Maint K – 2meqx10=20
deficite K 6x10=60
50. 1. INITIAL RESUSCITATION – DEFERRED 20ML/KG-200ML
2. WEIGHT 10 KG – (WEIGHT LOSS)= (10KG-9KG)/10KG *100%=
10% OF DEHYDRATION
3. TYPE – ISONATREMIC NA 138 MEQ/DL NORMA RATE 130-150 MEQ/DL
4. RATE OF FLUIDS AND ELECTROLYTES
Water needed Na needed K needs
Maintenance
Fluids (24 Hr)
100ml/kG=10kg*100ml
= 1000ml
3/100ml of
maint= 30 mEq
2/100ml of
maint.= 20 mEq
Deficit 100ml/kg=1000ml 8.4 mEq/100ml
8.4x10=84
6 mEq/100ml
6x10=60
Total 24 hR 2000 ml = 2 l 114 mEq 80 mEq
51. CASE 2. SCENARIO
� An infant with 4 days history of vomiting and diahhrea,
his mother giving him only water in the last 2 days.
� He AF and eyes are sunken. CR is 4-5 seconds, he has a
tachypnea, clear lung. BP 55/34. His current weight 5
kg (before illness 5.5 kg). Serum is 120 mEq/L.
Additional Na needed to correct Na to 130 mEq
Weightx0.6x(desired Na-Current Na) = 5.5x0.6x(130-120)
= 33 mEq
1) Initial Resuscitation
2) Determine % dehydration
3) Define the type of dehydration
4) Determine the type and rate of rehydration fluids
5) Final considerations
52. 1. INITIAL RESUSCITATION – DEFERRED
2. WEIGHT 5.5 KG – 10% OF DEHYDRATION
3. TYPE – HYPONATREMIC NA 120 MEQ/DL
4. RATE OF FLUIDS AND ELEQTROLYTES
Water needed Na needed K needs
Maintenance
Fluids (24 Hr)
100ml/kG=550ml 3/100ml of
maint= 16.5
mEq
2/100ml of
maint.= 11 mEq
Deficit 100ml/kg=550ml 8.4 mEq/100ml
8.4x5.5=42 mEq
6 mEq/100ml
6x5.5=33
Additional
NA
Total 24 hR 1100ml
To correct
with 130
mEq=33mEq
91.5 mEq 44 mEq
