DEHYDRATION
Dr Nadeem Zubairi
Dehydration
2 million infants and children die every year
in the developing countries
Case Study--Basim is 4 years old and his brother,
Ahmad, is 5 months old. Both children are brought to the clinic by their mother because of diarrhea and fever of 4 days duration. Basim has also vomited thrice.Doctor assesses the children and determines that Basim is severely dehydrated but Ahmad is only mildly dehydrated. Basim`s serum sodium is 170 mEq/L while that of Ahmad is 142 mEq/L
Case Study-AbdulAziz is a 40 days old first born child who is having vomiting since second week of life. He tends to vomit almost all of the milk taken immediatelyafter the feed and gets hungry again. Examinationreveals that he is moderately dehydrated and thereis an olive size mass in epigastric region.
CBC is unremarkable. Electrolytes: Na 131, K 3.0, Cl 95, bicarb 32. PH 7.45.
AbdulRahman,A 14-year-old male is brought to the Emergency Department via ambulance with a report of the patient being found unresponsive. He is a known case of Type 1DM and is on Insulin since last 7 years. Lately he was running fever and mother is not sure about regularity of doses during this illness.On examination AbdulRahman has altered consciousness level, acidotic breathing and has severe dehydration. Labs:TLC……… highSugar……402 mg/dlPH……… 7.15Ketone bodies ++++
Case Study-
Case Study-Rehana is a 5 year old child who had 60% burns following spillage of boiling water on trunk and lower limbs 02 days back. She is in the hospital.
Lately she is febrile, intake is less, tongue is dry. Her urine output is less and she is hypotensive.
WHAT IS COMMON IN ALL ?
DEHYDRATION
OBJECTIVES
At the end of this lecture you will able to know the followings:
*What is dehydration?*What are the causes of dehydration?*The clinical manifestaions of dehydration.*The investigations required.*Management of dehydration.
Distribution of Body Water
Intravascular
Interstitial
IntracellularICF
ECF Na+
K+
Cl-
Fluid composition varies at different ages
% of Water in the Body
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Newborn 6mo 2 yr adults
Different Ages
waterECFICF
Fluid Maintenance
Body Wt Fluid per day
0 – 10 kg 100 ml/kg
11 -20 kg 50 ml/kg
20 kg 20ml/kg
e.g. a child of 25kg
First 10 kg = 1000 ml
Second 10 kg = 500 ml
Remaining 5 kg = 20 ml
Total = 1700 ml/ pay i.e. per hr = 70 ml/ hr
Fluid Losses in InfantsLUNGS
URINE, FECES SKIN
Differences between children & adults
Surface Area (BSA)Metabolic RateKidney FunctionFluid Requirements
Reasons why infants & children are at > risk for developing fluid & electrolyte imbalanceIncreased % of body weight
is H2OLarge volume of ECFIncreased BSA (insensible
loss)Increased Metabolic rateImmature Kidneys
Dehydration is a condition that can occur with excess loss of water and other body fluids. Dehydration results from decreased intake, increased output (renal, gastrointestinal or insensible losses), a shift of fluid (e.g. ascites, effusions), or capillary leak of fluid (e.g. burns and sepsis).
CAUSES OF
DEHYDRATION
Conditions causing Fluid Imbalances
PhototherapyIncreased RRFeverVomitingDiarrhea *(Gastroenteritis)*Drainage tubes, blood lossBurns
DiarrheaDiarrheaMetabolic Acidosisloss of HCO3 from
G.I. Tract pH HCO3
Treatment: Correct base defecit, replace losses of with NaHCO3
VomitingVomiting Metabolic Alkalosis Loss of acid from
stomach pH HCO3
H+
Treatment: Prevent further losses and replace lost electrolytes
Example: Pyloric Stenosis
Heat stroke
FeverFeverEach degree of fever
increases basal metabolic rate (BMR) by 10%, with a corresponding fluid requirement
PhototherapyPhototherapy
Infant under phototherapy. Note that the eyes
are shielded and a diaper is used to contain the diarrheal stools.
Copyright © 1999, Mosby, Inc.
Mouth ulcers, stomatitis, pharyngitis, tonsillitis: pain may severely limit oral intake
BurnsBurnsFluid loss is 5-10
X greater than from undamaged skin
Abnormal exchange of electrolytes between cells and interstitial fluid
Burns: fluid losses may be extreme and require aggressive fluid management
Diabetic ketoacidosis (DKA).
Congenital adrenal hyperplasia: may have associated hypoglycaemia, hypotension, hyperkalaemia, and hyponatraemia.
Cystic fibrosis: excessive sodium and chloride losses in sweat.
Diabetes insipidus: excessive output of very dilute urine.
Thyrotoxicosis: increased insensible losses and diarrhoea.
Drainage Tubes/Drainage Tubes/Blood lossBlood loss
ASSESSING DEHYDRATION
IN CHILDREN
Manifestations of ECF Deficit (Dehydration)
S & SWeight lossBlood pressure dropDelayed capillary
refillOliguriaSunken fontanelDecreased skin
turgor
Physiologic BasisDecreased fluid vol.Inadequate circ. BloodDecreased vascular
volumeInadequate kidney circ.Decreased fluid volumeDecreased interstitial
fluid
Degree of Dehydration
Mild dehydration (3-5%)
Moderate dehydration (6-10%)
Severe dehydration (10-15%)
Mild Moderate SevereWeight loss Up to 5% 6-10% More than 10%Appearance Active,
alertIrritable, alert,
thirstyLethargic, looks sick
Capillary filling
(compared to your own)
Normal Slightly delayed Delayed
Pulse Normal Fast, low volume Very fast, threadyRespiration Normal Fast Fast and deepBlood pressure
Normal Normal or low Orthostatic hypotension
Very low
Mucous memb.
Moist Dry Parched
Tears Present Less than expected
Absent
Eyes Normal Normal SunkenPinched skin Springs
backTents briefly Prolonged tenting
Fontanel (infant sitting)
Normal Sunken slightly Sunken significantly
Urine flow Normal Reduced Severely reduced
Mild Moderate SevereWeight loss Up to 5% 6-10% More
than 10%Appearance Active, alert Irritable, alert, thirsty Lethargic,
looks sickCapillary filling
(compared to your own)
Normal Slightly delayed Delayed
Pulse Normal Fast, low volume Very fast, thready
Respiration Normal Fast Fast and deep
Blood pressure Normal Normal or low Orthostatic hypotension
Very low
Mucous memb. Moist Dry ParchedTears Present Less than expected AbsentEyes Normal Normal Sunken
Pinched skin Springs back Tents briefly Prolonged tenting
Fontanel (infant sitting)
Normal Sunken slightly Sunken significant
lyUrine flow Normal Reduced Severely
reduced
Earliest Detectable Signs
TachycardiaDry skin and mucous
membranesSunken fontanelsCirculatory Failure (coolness,
mottling of extremities)Loss of skin elasticityDelayed cap refill
Skin turgor is assessed by pinching the skin of the abdomen or thigh longitudinally between the thumb and the bent forefinger.
The sign is unreliable in obese or severely malnourished children.
Normal: skin fold retracts immediately.Mild or moderate dehydration: slow; skin fold visible for less than 2 seconds.
Mild or moderate dehydration: slow; skin fold visible for less than 2 seconds.
Severe dehydration: very slow; skin fold visible for longer than 2 seconds.
Other features of dehydration include dry mucous membranes, reduced tears and decreased urine output.
Additional signs of severe dehydration include circulatory collapse (e.g. weak rapid pulse, cool or blue extremities, hypotension), rapid breathing, sunken anterior fontanels
Loss of Skin Elasticity due to dehydration is not a reliable sign in malnourished children
What is considered oliguria in an infant or
child?<1ml/kg/hr
How would you measure U.O. for a
child who is not toilet trained?
Weigh diaper1 gram = 1 cc
TYPES OF
DEHYDRATION
Dehydration =Total Out > Total In
Types:Isotonic
Electrolyte = Water Hypotonic
Electrolyte > WaterHypertonic
Water > Electrolyte
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I so Hypo Hyper
Electrolytes
Water
The most common type of dehydration in
children is…..Isotonic
Hypernatremic dehydration Dehydration, characterized by increased concentrations of sodium
and chloride in the extracellular fluid, it results from diarrhea in infants.
The occurrence of the hypernatremia and hyperchloremia lies in the relatively greater expenditure of water than electrolyte via skin, lungs, stool and urine. The water deficit in these infants is primarily intracellular.
The majority of infants with this type of dehydration show varying
degrees of depression of central nervous system varying from
lethargy to coma. Convulsions are frequently observed.
Dilute solutions of electrolyte are indicated in rehydration. Rapid adjustment, however, appears to accentuate the CNS disturbance. Rehydration is best carried out slowly over a 2- to 3-day period.
HYPERNATREMIC DEHYDRATION
Major danger due to condition: Brain hemorrhage...shrinkage of brain leading to tearing of vessels
Major danger due to treatment: Brain edema due to movement of waterinto the brain cells. Occurs if treatment istoo rapid
What lab tests provide useful information
when the concern is dehydration?
Usually no tests are needed if child is clinically stable
CBC, Urea Electrolytes, Blood gasesStool RE and C/S
MANAGEMENT OF
DEHYDRATION
Management of Mild to Moderate Dehydration
Oral RehydrationPedialyteInfalyteRehydralate
Rules regarding rehydration50-100ml/kg
within 4 hours
Home Management
Oral RehydrationOral fluids commonly given to
children when sick:Apple juice (low Na, High K)Coke (Low Na, Low K, High sugar)Pepsi (Na—little better than Coke, no K)7-Up (sugar, small Na, no K)Gatorade (high Na, sugar)Grape juice (low Na, high K)Orange juice (low Na, High K)Milk (has Na, K, Cl, HCO3)
ORAL REHYDRATION SOLUTION (ORS)
ORS
Developed 1940s in Dhaka Bangladesh
ORS
Most important medical discovery of the 20th century
ORS
5 million deaths / yearAfter ORS
2 million deaths / year
ORS components
WHO/UNICEF
Na = 90 mmol/l k = 20 mmlo/l cl = 80 mmol/l glucose = 111mmol/l Osmol = 311 mmol/l
WHO vs. Hypo-osmolar ORS
WHO/UNICEF Hypo-osmolar
Na = 90 mmol/l Na = 60 mmol/l k = 20 mmlo/l k = 20 mmlo/l cl = 80 mmol/l cl = 50 mmol/l glucose = 111mmol/l glucose = 84 mmol/l Osmol = 311 mmol/l Osmol = 224 mmol/l
Hypo-osmolar ORS
Many studies support the use of reduced osmolarity ORS but the debate is not resolved. It is preferred in severely malnourished (marasmic) child as the standard (old) WHO ORS may cause hypernatremia
ORT vs. I/V Therapy
ORT is as effective as I/V fluid for rehydration of moderately dehydrated children due to G/E in the E/D. ORT Demonstrated no inferiority for successful rehydration at 4 hours and hospitalization rate.
A randomized controlled trial by P Spandorfer et al Pediatrics Feb.2005
ORT vs. I/V Therapy
Although no clinically important differences between ORT and IVT, the ORT group did have a higher rate of paralytic ileus, and the IVT group exposed to risk of intravenous therapy. For every 25 children treated with ORT one fail and require IVT
L Hartlig The Cochrane Database of Systematic Reviews 2006 Issue 4
Reluctance to use ORT
?
Reluctance to use ORT
People do not consider ORT high-tech enough.
Physicians prefer I/V fluids.It takes time to educate parents re ORT.Time consuming for busy parents.
Moderate to Severe
Dehydration Management
Goals of IV TherapyExpand ECF volume and improve circulatory and renal function (Isotonic solution .9%NS,LR, D5W)K+ after kidney function is assessedBegin oral feedings
MANAGEMENT OF DEHYDRATION-Replace Phase 1: Acute Resuscitation :
Give Lactated Ringer OR Normal Saline at 10-20 ml/kg IV over 30-60 minutes.
May repeat bolus until circulation stable -Calculate 24 hour maintenance requirements
Formula: First 10 kg: (100 cc/kg/24 hours) Second 10 kg: (50 cc/kg/24 hours) Remainder: (20 cc/kg/24 hours)
Example: 35 Kilogram Child Daily: 1000 cc + 500 cc + 300 cc = 1800 cc/day
-Calculate Deficit: Mild Dehydration: (40 ml/kg) Moderate Dehydration: (80 ml/kg) Severe Dehydration: (120 ml/kg)
MANAGEMENT Continue ----------Calculate remaining deficit:
Substract fluid resuscitation given in Phase 1 -Calculate Replacement over 24 hours:
First 8 hours: 50% Deficit + Maintenance Next 16 hours: 50% Deficit + Maintenance
Determine Serum Sodium Concentration Hypertonic Dehydration (Serum Sodium > 150) Isotonic Dehydration Hypotonic Dehydration (Serum Sodium < 130)
Add Potassium to Intravenous Fluids after patient voids urine Potassium source
Potassium Chloride Potassium Acetate for Metabolic Acidosis
Potassium dosing Weight <10 kilograms: 10 meq KCl /liter glucose Weight >10 Kilograms: 20 meq KCl /liter glucose
Name of Solution Type of Solution Ingredients in 1-Liter
Uses Complications
0.45% Sodium Chloride
Shorthand Notation:½NS
HypotonicpH 5.6
77 mEq Sodium77 mEq Chloride
hypotonic hydration; replace sodium and chloride; hyperosmolar diabetes
if too much is mixed with blood cells during transfusions, the cells will pull water into them and rupture
0.9% Sodium Chloride Shorthand Notation:
NS
IsotonicpH 5.7
154 mEq Sodium154 mEq Chloride
isotonic hydration; replace sodium and chloride; alkalosis; blood transfusions (will not hemolyze blood cells)
None known
3% Sodium Chloride HypertonicpH 5.0
513 mEq Sodium513 mEq Chloride symptomatic hyponatremia due to excessive
sweating, vomiting, renal impairment, and excessive water intake
rapid or continuous infusion can result in hypernatremia or hyperchloremia
5% Sodium Chloride HypertonicpH 5.8
855 mEq Sodium855 mEq Chloride
5% Dextrose in Water
Shorthand Notation:D5W
IsotonicpH 5.0
5 grams dextrose(170 calories/liter)
isotonic hydration; provides some calories
water intoxication and dilution of body's electrolytes with long, continuous infusions10% Dextrose in Water
Shorthand Notation:
D10W
HypertonicpH 4.3
10 grams dextrose(340 calories/liter)
may be infused peripherally;hypertonic hydration; provides some calories
5% Dextrose in 1/4 Strength (or 0.25%) Saline
Shorthand Notation:D5¼NS
HypertonicpH 4.4
5 grams Dextrose34 mEq Sodium34 mEq Chloride
fluid replacement; replacement of sodium, chloride and some calories
vein irritation because of acidic pH, causes agglomeration (clustering) if used with blood transfusions; hyperglycemia with rapid infusion leading to osmotic diuresis
Table of Commonly Used IV Solutions
Lactated Ringer’’s (RL): Isotonic, 273 mOsm/L. Contains 130 mEq/L Na+, 109 mEq/L Cl--, 2mEq/L lactate, and 4 mEq/L K+. Lactate is used instead of bicarb because it’’s more stable in IVF during storage. Lactate is converted readily to bicarb by the liver. Has minimal effects on normal body fluid composition and pH. More closely resembles the electrolyte composition of normal blood serum. Does not provide calories.Contra-indication: Pyloric stenosis(metabolic alk)
Why is it necessary to use a pump or other volume control when
infusing Ivs into children?
Avoid overloadSpecifically monitor input
When to resume normal diet?
Special Considerations
Antibiotics
Anti- emetics
Anti-diarrheal agentsAntimotility drugs, slow intestinal transit but have little effect on the total stool volume and may have serous side effect including ileus. They are not advised for infants or children
Case Study--Basim is 4 years old and his brother,
Ahmad, is 5 months old. Both children are brought to the clinic by their mother because of diarrhea and fever of 4 days duration. Basim has also vomited thrice.Doctor assesses the children and determines that Basim is severely dehydrated but Ahmad is only mildly dehydrated. Basim`s serum sodium is 170 mEq/L while that of Ahmad is 142 mEq/L
Ahmad….. Mild dehydrationWeight….. 7 kgsIsonatremicORS
Basim……. Severely dehydratedWeight……. 15 kgsHypernatremicTotal deficit: 15 X 100-120=1500- 1800 mlType of fluid:0.45% Normal SalineDuration of therapy:48 to 72 hoursFrequent check