ASSESSING
DEHYDRATION
IN
CHILDREN
INTRODUCTION
Children are particularly susceptible to dehydration
with acute gastroenteritis or other illnesses that
cause vomiting, diarrhoea and fever. Considerable care is
required in the assessment and management of
dehydration in children, because underestimation of
dehydration may lead to inadequate management and
therefore complications, while overestimation of fluid
deficit can result in inappropriate rehydration therapy.
It is therefore essential to make an accurate
assessment of the degree of dehydration in children in
order to make appropriate treatment decisions
DEFINITION
OF
DEHYDRATION
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
Gastroenteritis
Mouth ulcers, stomatitis, pharyngitis, tonsillitis:
pain may severely limit oral intake
Diabetic ketoacidosis (DKA)
Febrile illness: fever causes increased insensible
fluid losses.
Burns: fluid losses may be extreme and require
aggressive fluid management
Congenital adrenal hyperplasia: may have
associated
hypoglycaemia, hypotension, hyperkalaemia, and
hyponatraemia.
Gastrointestinal obstruction, e.g. pyloric stenosis:
often associated with poor intake, vomiting.
Bowel ischaemia may cause extensive capillary
leak and shock.
Heat stroke
Cystic fibrosis: excessive sodium and chloride
losses in sweat.
Diabetes insipidus: excessive output of very
dilute urine.
Thyrotoxicosis: increased insensible losses and
diarrhoea.
ASSESSMENT
Clinical assessment of dehydration can be difficult,
especially in young infants, and rarely predicts the exact
degree of dehydration accurately.
The most useful individual signs for predicting 5%
dehydration in children are an abnormal capillary refill
time, abnormal skin turgor and abnormal respiratory
pattern.
Combinations of examination signs provide a much
better method than any individual signs in assessing the
degree of dehydration.
Of the clinical indicators used, the pinch test (skin
turgor) has been shown to be the most reliable in
several studies but is still not a reliable test when
used without other clinical indicators.
One proposed assessment scale using general
appearance, eyes, mucous membranes, and tears,
has been shown to be effective in assessing
dehydration in children
The assessment of dehydration in diabetic
ketoacidosis (DKA) is particularly difficult in view
of extravascular and intravascular dehydration,
metabolic acidosis affecting the clinical signs of
dehydration, and the overall catabolic state of
the patient. The majority of patients with DKA
have moderate (4% to 8%) dehydration, but
clinical assessment overestimates the percent
dehydration in two thirds of patients
The history and laboratory tests provide only
modest benefit in assessing dehydration.
Clinical assessment therefore comprises
some of the following indicators of
dehydration
Loss of body weight:
oNormal: no loss of body weight.
oMild dehydration: 5-6% loss of body
weight.
oModerate: 7-10% loss of body weight.
oSevere: over 10% loss of body weight.
Clinical features of mild-to-moderate
dehydration; 2 or more of:
Restlessness or irritability.
Sunken eyes (also ask the parent).
Thirsty and drinks eagerly
Clinical features of severe dehydration; 2 or
more of:
Abnormally sleepy or lethargic.
Sunken eyes.
Drinking poorly or not at all
PINCH TEST
(SKIN TURGOR):
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
CLINICAL
ASSESSMENT
OF
DEHYDRATION
Mild
Moderate
Severe
Weight loss
Up to 5%
6-10%
More than 10%
Appearance
Active, alert
Irritable, alert, thirsty
Lethargic, looks sick
Capillary 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
Parched
Tears
Present
Less than expected
Absent
Eyes
Normal
Normal
Sunken
Pinched skin
Springs back
Tents briefly
Prolonged tenting
Fontanel (infant
sitting)
Normal
Sunken slightly
Sunken significantly
Urine flow
Normal
Reduced
Severely reduced
When we talk of 5% dehydration, it means that the child
has lost an amount of fluid equal to 5% of the body
weight. So,
A 10 kg child who is 5% dehydrated will weigh 9.5 kg.
A 10 kg child who is 10% dehydrated will weigh 9 kg.
A 5 kg child who is 10% dehydrated will weigh 4.5 kg.
The child's current (dehydrated) weight can be used
for calculation of dehydration and maintenance fluids.
After all, clinical assessment of dehydration, and therefore
the volume needed for correction, is approximate!
ORAL
REHYDRATION
SOLUTION
(ORS)
Recipe 1
Making a 1 (one) litre solution using Salt, Sugar and Water
Ingredients:
• One level teaspoon of salt
• Eight level teaspoons of sugar
• One litre of clean drinking or boiled water and then
cooled
5 cupfulls (each cup about 200 ml.)
Preparation Method:
Stir the mixture till the salt and sugar dissolve
Recipe 2
Making a 1/2 (half) liter solution using
Salt, Sugar and Water
Ingredients:
A 3 finger pinch of salt ( approx. 1.75 gms.)
A scoop of sugar ( approx. 20 gms.)
1/2 (half) liter of clean drinking or boiled
water
2.5 cupfuls (each cup about 200 ml.)
PREPARATION METHOD:
Pour 1/2 (half) liter of clean drinking or boiled water,
after it has cooled, into a large vessel.
Add a 3-finger pinch of salt (approx. 1.75gms).
Taste the solution. It shouldn't be more salty than your
tears.
Add a scoop of sugar ( approx. 20 gms.)
Stir the mixture till the salt and sugar dissolve.