Block 9 - Unit 8 Blood fluid warmers

Without reference, identify principles about
Blood Fluid Warmers with at least 70 percent
Body temperature
◦ Used during various clinical procedures (mainly for
surgeries) to raise the temperature of refrigerated and
room temperature blood or IV fluids as they are
infused into the patient
◦ Normothermia – normal core body temperature
◦ When dealing with a medical patient (surgically or
clinically) normothermia is always important
 If a patient is over or under normal temperature the
body will strive for normothermia
This extra effort will take away from the body’s ability to
 Hypothermia is the most frequent concern
◦ Negative effects of hypothermia
 Cardiac arrhythmias – myocardial infarctions are the
leading cause of unexpected death after otherwise
routine surgery
 Coagulopathy (prolonged or excessive bleeding) –
caused by the body’s decreased release of
 Decreased metabolism of numerous drugs causing
slower recovery from anesthesia
 Increased surgical recovery times and increased
length of hospitalization
 Increased risk of infection
 Raising the temperature of blood or IV fluids before
they are infused into a patient can significantly
reduce the occurrence of hypothermia
 In addition to hypothermia, infusion of fluid
below normal body temperature can induce or
aggravate physiologic conditions, such as
cerebral perfusion
 It is important to note that blood/fluid warmers
only help to maintain normothermia
They generally do not transfer enough heat to
significantly raise the body temperature
This means they cannot effectively re-warm patients
who are already hypothermic
To significantly raise the body temperature of a patient
other means, such as hypo/hyperthermia or BairHugger
units must be used
◦ Blood/fluid warmers are mainly used in surgery,
but may also be used in other areas such as:
 Emergency department
 Intensive care unit
 Some general patient care areas
 Blood bank
◦ Generally, blood/fluid warmers are setup and
operated by either an anesthesiologist or a nurse
anesthetist before and during a surgical
◦ The decision to use a blood/fluid warmer and the
correct type to use must be made by the clinician
and includes the following variables:
 Patient size and weight
 Duration of the surgical procedure
 Rate of infusion or the total volume of
blood/fluid to be infused
 Temperature of the blood/fluid to be infused
 Availability of other patient-warming
 Clinician preference
◦ Blood/fluid warmers are typically categorized by
the method they use to warm blood/IV solutions
◦ Most are in-line devices mounted on an IV pole.
They warm the solution bag or infusion device
and the patient line and can be used in
conjunction with the primary types of infusion
devices including
 Gravity
 Pressure
 Pump
◦ The two primary methods of heating blood or IV
fluids are water bath and dry heat
 Water bath
These units utilize a tank of warm water and special
The tubing has an outer sheath in which warmed water
from the tank is circulated
Blood or IV fluid passes through an inner tube, which
runs between the sheath, and is warmed by the
principle of conduction
Warmed blood or IV fluids are infused to the patient
 Dry heat plate
 IV tubing is passed between two warming plates
 Blood/fluid warming takes place through conduction
between the plates and the fluids
 Dry heat cassette
 Blood or IV fluids pass through a special chamber or
 The cassette/cartridge fits in-between two warming
 The blood/fluids are warmed through conduction
Advantages/disadvantages of each method
◦ Water bath
 Provides precise and controlled warming of
blood/fluids for a wide range of flow rates
 Require special disposable tubing sets
 Water from tank can be spilled
◦ Dry heat plate
 Generally only effective for heating blood/fluids
infused at low rates
 Do not provide rapid heating of blood/fluids
 Do not require special tubing sets
 Relatively simple devices
◦ Dry heat cassette
 Provide rapid and accurate warming of
blood/fluids for a wide range of flow rates
 Require special tubing/cassette sets
◦ In addition to the above units, there are some
high-flow units that can both warm and deliver IV
solutions/blood and are capable of warming and
infusing fluids at higher rates than conventional
blood/fluid warmers Blood/Fluid
 All units have primary and secondary (backup)
thermostatic or electronic controls to regulate
 All units have some type of circuitry that
indicates the plate or water-bath temperature;
however, the actual blood/solution temperature
is not displayed
 All units have an alarm circuit that terminate
operation when an over-temperature condition
occurs (usually slightly above 42°C – the point
at which red blood cells are damaged)
Visual/audible alarm
Heater cutoff