Severe dehydration

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

01020304050607080

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

01020304050607080

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