Principles Of Intravenous
Infusions And Blood
Transfusions
Sharon Harvey
Definition of an
Intravenous Infusion
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The term intravenous can be
described as administering a solution
into or within a vein
The term infusion is defined as a slow
injection of a substance into a vein or
subcutaneous tissue
Advantages of using an
intravenous route
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An immediate therapeutic effect is
achieved due to a rapid delivery of the
drug/fluid to target sites
Pain and irritation caused by some
substances when given intra muscularly
or subcutaneously
if patient cannot tolerate drug by oral
route
Disadvantages of using the
intravenous route
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The inability to recall the drug
Insufficient control of administration may
lead to speed shock
Additional complications such as
microbial contamination (intrinsic or
extrinsic)
Vascular irritation - chemical Phlebitis
Drug incompatibilities
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Some drugs cannot be absorbed by any
other route
A better control is offered over the rate
of administration
IN ORDER TO ADMINISTER
FLUIDS OR DRUGS SAFELY
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The nurse must have:
knowledge of the solutions
Their effects and side effects
The factors that affect flow
The complications that can occur
Gravity flow devices
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Gravity infusion devices depend on
gravity to drive the infusion. The
system consists of an administration set
containing a drip chamber and utilizing
a roller clamp to control flow which is
measured by counting the drops
Gravity infusions are ideal for infusing
fluids which do not need to be infused
with absolute precision
Factors That Influence Flow
Rates.
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The composition, viscosity and
concentration of the fluid affect flow e.g.
An infusion of cold blood will result in
venospasm and impede the flow rate
IV fluids run by gravity and any changes
in their height will alter the flow rate.
Any changes in patient position can also
alter the flow rate
Flow Rates Can Also Be Affected
by the Following:
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The condition and size of the patients
vein e.G. Phlebitis can reduce the
lumen size and reduce flow
The gauge of the cannula/catheter
The position of the device within the
vein, if it is up against the vein wall
The site of the vascular access. The
flow may be affected by limb position
such as the elbow joint
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Kinking, pinching or compression of the
cannula of the administration set may
cause rate variation
Occlusion of the device due to clot
formation which may result from a BP
cuff on the infusion arm, or with the
patient lying on the side of the infusion.
The patient - The dangers
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Patients occasionally adjust the control
clamp or other parts of the delivery
system! Pumps today have tamper
proof features (Jensen 1995)
Positioning of the patient will affect the
flow and patients should be instructed
to keep the arm lower than the infusion
on a gravity device (Dolan 1999)
Complication of inadequate flow
control
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Fluid overload with accompanying electrolyte
imbalance
Metabolic disturbances
Toxic concentrations of medication resulting
in speed shock
Air embolism due to containers running dry
before expected.
An increase in venous conmplication such as
a chemical phlebitis caused by reduced
dilution of irritant substances e.g potassium.
Complications associated with
under infusion
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Dehydration
Metabolic disturbances
A delay response to medications or
below the therapeutic dose
Occlusion of a cannula due to a
cessation of flow.
CLIENT GROUPS
ASSOCIATED WITH FLOW
CONTROL PROBLEMS:
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INFANTS AND YOUNG 
CHILDREN
THE OLDER PERSON
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PATIENTS WITH
COMPROMISED
CARDIOVASCULAR
STATUS
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PATIENTS WITH
IMPAIRMENT OR
FAILURE OF ORGANS
PATIENTS WITH
MAJOR SEPSIS
PATIENTS SUFFERING
WITH SHOCK
WHATEVER THE CAUSE
POST-OPERATIVE OR
POST TRAUMA
PATIENTS
PATIENTS RECEIVING
MULTIPLE
MEDICATIONS WHOSE
CLINICAL STATUS
COULD CHANGE
RAPIDLY
Calculating flow rate
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Flow rate is calculated using a formula
that requires the following information:
The volume to be infused, the number
of hours the infusion is running over and
the drop rate of the administration set.
Volume to be infused x drop rate
Time in hours x 60mins
=drops in minutes
Infusion Device
Definitions
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An infusion device is designed to deliver
measured amounts of drug or fluid
either intravenously or subcutaneously
over a period of time. This is set at an
appropriate rate to achieve the desired
therapeutic response and prevent
complications. (Mallet & Bailey 1996)
Types of infusion pumps
– Drip rate pumps: These were the first
infusion pumps which controlled the rate of
drop formation using a standard gravity set
– Volumetric pump: This works by
calculating the volume delivered. This is
achieved when the pump measures the
volume displaced in the reservoir. It
calculates that every fill and empty cycle of
the reservoir delivers the given amount of
solution
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Aims of Intravenous Infusions
devices.
The aims of using an infusion device is
to ensure the delivery of a drug or fluid
to a patient at a constant rate over a set
period of time with no adjustments to
“catch up”
This is not only to ensure a therapeutic
response but also to avoid
complications of over and under
infusion
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The use of infusion devices both
mechanical and electronic has
increased the level of safety in IV
therapy. However, the equipment is
only as good as the person who is
selecting and setting up!
Advantages and disadvantages of
infusion pumps
– The disadvantages are that these are
usually relatively expensive and dedicated
administrations sets are required. Use of a
wrong set could result in error even if the
pump appears to work
– These pumps are able to overcome
resistance to flow by increasing delivery
pressure and do not rely on gravity
– Some are also complicated to set up which
can lead to error
Additional guidelines
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the infusion container should hang no
longer than 24 hrs. This is reduced to 8
hrs for blood and blood products.
Recent research indicates that changing
sets every 48 - 72 hrs is not associated
with increased infection rates and can
result in considerable saving
(department of health)
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It is desirable to record the date and
time that the set is due to be changed
The site of the infusion should be
inspected every shift for complications
such as infiltration or inflammation
Dressings should be changed every 24
hrs or if it appears to be dirty or loose
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It is desirable to record the date and
time that the set is due to be changed
The site of the infusion should be
inspected every shift for complications
such as infiltration or inflammation
Dressings should be changed every 24
hrs or if it appears to be dirty or loose.
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The dead space in the equipment has
also been identified as a reservoir for
micro-organisms which may be
released into the circulation (Weinbaum
1987)
Objectives of transfusion
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Increase circulating blood volume after
surgery, trauma or haemorrhage
To increase the number of red blood
cells and aid haemoglobin maintenance
Provide cellular components as
replacement therapy
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Further recommendations in the light of
recent research have shown that a
closed system of infusion is maintained
whenever possible
This reduces the risk of extrinsic
bacterial contamination
Principles of blood transfusions
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Blood replacement or transfusion is the
iv administration of whole blood or blood
product such as plasma, packed red
blood cells or platelets.
Blood groups and types
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The determination of blood groups is
based on the presence or absence of A
and B red cell antigen
The most important grouping for
transfusion purpose is the ABO
system, which includes A,B,O,AB
blood types
The Rh factor
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Other considerations when matching for
blood transusions is the Rh factor,
which is an antigenic substance in the
erythrocyte of most people
A person with the factor is Rh positive
and a person without the factor is Rh
negative
Blood transfusions
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Transfusing blood or blood products is a
nursing procedure. The nurse is
responsible for the assessment before,
during and after the transfusion and for
regulation of the transfusion.
Assessment is critical because of the
risk of allergic reactions
Guideline Checks
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To ensure that the right client receives
the correct type of blood or blood
product a thorough procedure is used to
check the identity of the blood or blood
product, the compatibility of the blood
and the client
Two registered nurses must check the
label on the blood product against the
clients identification number, blood
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Because of the dangers of a reaction it
is very important to follow guidelines for
the correct policy of administration
The nurse must obtain the patients
baseline vital signs before the
transfusion begins as this allows the
nurse to determine when changes in
vital signs occur, which indicates a
transfusion reaction occurring
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The expiry date on the blood is also
checked
Even if a minor discrepancy exists the
blood should not be given and blood
bank notified immediately
Initiation of the transfusion begins
slowly to allow for early detection of a
reaction
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The rate of transfusion is usually
specified by the doctor
Ideally a unit of whole blood or packed
red blood cells is transfused over 24hours.
Beyond 4 hours there is a risk of the
blood becoming contaminated
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Throughout the infusion the nurse
monitors periodically for side effects,
and assesses vital signs, and records
all findings
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A reaction to the blood will usually occur
in the first 15 mins. If a reaction is
anticipated the nurse will obtain vital
signs more frequently
The rate of transfusion is usually
specified by the doctor
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Ideally a unit of whole blood or packed
red blood cells is transfused over 24hours.
Beyond 4 hours there is a risk of the
blood becoming contaminated
Transfusion reactions and nursing
interventions
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A transfusion reaction is a systemic
response by the body to incompatible
blood
Blood transfusion reactions are life
threatening, but prompt nursing
intervention can maintain the clients
physiological stability
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If a blood reaction is suspected the
nurse stops the infusion immediately
The line is kept open by the infusion of
0.9% saline solution
The doctor is informed immediately
The nurse remains with the patient
monitoring their vital signs as often as
every 5 mins
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The nurse prepares to administer
emergency drugs I.e.
antihistamines/adrenaline etc and if
needed to perform CPR
The blood containers, giving set, labels,
form etc are retained and returned to
blood bank for further investigation
Summary
– The nurse is responsible for the
administration of intravenous fluids by the
methods listed. In order to do this he/she
requires a thorough knowledge of the
principles, and their application, and a
responsible attitude
– The nurse must also be able to justify any
actions taken and be prepared to be
accountable for the action taken(UKCC
1992)