Principles Of Intravenous Infusions And Blood Transfusions

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Principles Of Intravenous Infusions And Blood
Transfusions

• Sharon Harvey

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Definition of an Intravenous Infusion

• 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

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Advantages of using an intravenous route

• 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

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Disadvantages of using the intravenous route

• 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

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IN ORDER TO ADMINISTER FLUIDS OR DRUGS SAFELY

• The nurse must have
• knowledge of the solutions
• Their effects and side effects
• The factors that affect flow
• The complications that can occur

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Gravity flow devices

• 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

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Factors That Influence Flow Rates.

• 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

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Flow Rates Can Also Be Affected by the Following

• 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.

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The patient - The dangers

• 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)

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Complication of inadequate flow control

• 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.

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Complications associated with under infusion

• Dehydration
• Metabolic disturbances
• A delay response to medications or below the
  therapeutic dose
• Occlusion of a cannula due to a cessation of flow.

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CLIENT GROUPS ASSOCIATED WITH FLOW CONTROL
PROBLEMS-

• INFANTS AND YOUNG CHILDREN
• THE OLDER PERSON
• PATIENTS WITH COMPROMISED CARDIOVASCULAR STATUS
• 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

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Calculating flow rate

• 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

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Infusion Device Definitions

• 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)

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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!

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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

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Additional guidelines

• 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)

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Objectives of transfusion

• 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

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Principles of blood transfusions

• Blood replacement or transfusion is the iv
  administration of whole blood or blood product
  such as plasma, packed red blood cells or
  platelets.

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Blood groups and types

• 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

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The Rh factor

• 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

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Blood transfusions

• 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

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Guideline Checks

• 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 group and complete name.

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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 2-4hours.
• 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 2-4hours.
• Beyond 4 hours there is a risk of the blood
  becoming contaminated

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Transfusion reactions and nursing interventions

• 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

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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)