When the amount of fluid lost from
the body is equal to the amount of
fluid taken in, the body is in fluid
Fluid in our body is found within the body
cells (intracellular), surrounding
the cells (interstitial) and within
the blood vessels (intravascular).
It is our bodies' principal chemical
component, comprising, on average,
60 percent of our weight.
In obese individuals and the
elderly, total body
fluid can be significantly lower.
Fluid is constantly being lost by the body
perspiration, expired air (as water
vapour), urine, feaces, and negligible amounts in tears and
saliva. It is replaced in
our daily basic
intake of food and drink.
There is no easy answers as to how
much water a person is required to
drink each day. Studies have
produced varying recommendations
over the years, but in truth, each
individual water requirements depend
on many factors, including his
health and how active he is.
Monitoring of fluid balance is required for
patients with renal failure,
electrolyte imbalance, or severe
vomiting and diarrhea. It is also
necessary for patients with
nasogastric tubes and drainage
collection devices. In
addition, patients receiving
intravenous therapy and those taking medicines such as diuretics
and corticosteriods also need to
have their fluid balance monitored.
These measurements are
important to help evaluate a patient fluid and electrolyte
balance, to suggest various diagnosis, and
allows for prompt intervention to
correct the imbalance. Records
of all intake and output must be kept meticulously in an Intake and Output Chart (I/O Chart).
All amounts must be measured and
record in milliliters. Do not estimate. If the
patient is able to cooperate, he
should be encouraged to help in
keeping an accurate record of his
daily fluid intake and output.
At the end of a 24-hours period, add up the total intake and output.
patient's fluid status in relation
to the disease process, medication
regimen, diet, and activity ordered
by your healthcare professionals.
The patient is said to be in
negative fluid balance if his output
is greater than his intake.
Conversely, a positive fluid balance
intake is greater than output. If the difference is alarming,
consult your doctor. Keep the chart to show to the doctor, and start a fresh one for the next
Items Required for Measuring Intake and Output
Two jugs marked in milliliters, one for intake and the other for
output. You can also work out the capacity of any container
and mark it.
Gloves (for handling excretions such as urine and
Intake and output chart to record all measurements and
Reference Chart for
Utensil & Measurement
Quantity in Milliliter
1 large glass
*May varies with difference
sizes of utensils.
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Fluid intake refers to all fluid entering
the patient's body. It also includes foods that
are liquid at room temperature, such as ice chips,
ice-cream, and certain beverages.
Measure any fluids offered to the patient and make a note of how much the patient drinks
and the time of the day at which it is drunk.
If the patient is drinking from a jug,
obtain the total intake by subtracting the fluid
remaining in the jug at the end of the day plus any
You can also pre-measure the drinking
glasses or bowls most
commonly used by the patient. So when the patient
tell you that he had "one glass of water," you will know
Measure ice chips by multiplying the
volume by 0.5; when melted, the
volume of ice is approximately half
its previous volume.
For yogurt, ice cream, gelatin,
packet or canned drinks, measure the
amount printed on the labels.
Measure the amount of feeds through
nasogastric tube by noting the
volume of the bag at the beginning
of the feeding and then subtracting
he amount left at the end of the
feeding. Remember to include
any feeding that is added during the
Intravenous intake (drips) can also
be measure using the above method.
If water is used to flush the
nasogastric tube, record the amount
used for irrigation in the intake
and output chart.
Fluid output refers to all fluid that leaves
the patient's body. This includes urine, loose stools, vomitus,
aspirated fluid, excessive perspiration, and drainage from
surgical drains, nasogastric tubes, and chest tubes.
container marked with milliliters to collect fluid
output. Be sure to label the
container "FOR MEASURING OUTPUT ONLY" to prevent
confusion with intake container.
Always wear gloves when handling body fluids.
Any amount not measured due to any reasons such
as patient passed urine while in the toilet should be documented,
otherwise the chart becomes inaccurate and misleading.
In cases such as vomits or diarrhoea, record the
number of time it was passed. For such
cases, check with your doctor in advance if it is necessary to measure
the exact amount.
It is also important to make a note of the fact
if the patient is sweating.
If the patient has drainage, record the amount of the
drainage. It is important to document the source
of the drainage especially if he has more than one
If patient is on intermittent or continuous irrigation,
calculate the true output by measuring the total output
and subtracting the total irrigation infused.
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Dehydration can be defined as "the
excessive loss of water from the
It can be caused by losing too much
fluid (as in vomiting
not drinking enough water, or both.
The best way to treat dehydration is
to prevent it from occurring.
Always encourage the patient to
drink during an illness, and
remember that a person's fluid needs
are greater when he has fever,
vomiting, or diarrhea. If you
suspect excessive fluid loss during
an illness, inform your doctor
DO NOT wait for signs of
Signs of dehydration include:
Flushed and dry skin*1
Dry and furred tongue
Low or no urine output
Concentrated urine appears dark
Sunken fontanelles (the soft
spot on the top of the head) in
Increase breathing and heart
blood pressure causing
lightheadedness (worsening on
Delirium or unconsciousness in
most serious cases
*1 Dry skin in an elderly is not a
reliable indication of dehydration
as skin automatically loses moisture
and elasticity with age. A
better barometer is the color of
urine: clear or light-colored urine
means well hydrated, whereas a dark
concentrated color usually
*2 A capillary nail refill
test can be done by pressing firmly
on a fingernail bed for 5 seconds
and measure the speed at which blood
returns after the pressure is
released. In normal person,
capillary refilling should take less
than 3 seconds.
*3 You can test the hydration state of
your patient by simply pinching up
the skin on his hand into a fold. If
dehydrated, the skin
may lack its normal elasticity and
sag back into position slowly.
Normally, skin springs right back
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