ABC of blood
Transfusion?- How many of U have transfused bllod in last 5 yers?? Here are some tips for U who face such
unpleasant situation.
Hemorrhage
is the leading cause of intensive care unit
admission and one of the leading
causes of death in the obstetric population .
This emphasizes the importance of a working
knowledge of the indications for
and complications associated with blood product replacement in obstetric practice. This article provides
current information
regarding preparation for the administration of blood products
discusses alternatives to banked
blood in the obstetric population
and introduces pharmacological strategies for treatment of hemorrhage ,
Preparing for transfusion step 1: How to recheck the group / type a blood of recipient : Your own pt at ward: : Preparing
for an obstetric hemorrhage requires
the drawing of a blood sample from the patient to obtain
cross matched blood. The first
step in the process of preparing
blood is determining ABO type and the presence or absence
of Rh factor. To determine ABO
type the blood is mixed with commercially available antibodies
that react with A or B antigens
on the patient’s
erythrocytes causing agglutination
. The Rh factor status is also classified by this method. Then the blood type is confirmed by mixing
the patient’s blood with cells
that contain A or B antigens. Because most people
have antibodies to antigens
that they lack
agglutination will occur when antigen antibody complexes are present.
Step 2: Verify & check the pts blood & screened
her serum for common antibodies
. Screening involves mixing the recipient’s blood with commercially available antigens. If red blood cell agglutination or hemolysis occurs
antibodies are present and must
be characterized .
Step 3: You are anxious as PPH is continuing : You are constantly
loitering outside the blood bank:: This initial type and
screen takes approximately 45
minutes and is best for patients at low risk for
requiring blood transfusion . The most recent American Society of
Anesthesilogists Practice
Guidelines for Obstetric Anesthesia state that a
routine blood cross match is not necessary for healthy and
uncomplicated parturients for vaginal
or operative delivery
.
The decision
whether to order to require a blood type
and screen or crossmatch should be based on maternal history anticipated
hemorrhagic complications and local
institutional policies.
What is cross matching?? Patients should undergo blood cross matching when blood transfusion is imminent or likely To cross match blood
the recipient’s blood is mixed with the donor’s to mimic the transfusion . This
process detects antibodies in
the Kell Duffy Kidd
and MN groups as well as
antibodies that are present in
low titers and that do not agglutinate easily. Blood
cross matching typically takes
an additional 15-45 minutes after the blood has been
typed and screened.
In an
emergency where the patient requires
transfusion before type specific
or cross matched blood can be obtained , type – O blood
can be administered. In
obstetric patients it is
especially important to administer type – O Rh
negative blood because of the
risk of Rh sensitization . Cross
matched blood should be
administered as soon as it
is available because
the estimated risk of a hemolytic transfusion reaction
with this emergency blood has
been reported to be as high
as 5% although publications with trauma patients
report much lower complication
rates.
The
American Society of
Anesthesiologists Task Force
on Obstetric Anesthesia and the American College of Obstetricians and Gynecologists recommend
that all facilities providing
obstetric care be prepared
to manage hemorrhagic
emergencies. Immediate
availability of such equipment
as hand inflated pressure bags ,
an automatic rapid infusion system a fluid warmer and a forced air warming device is
recommended. Knowledge of
blood bank capability is paramount and resources vary depending on the hospital . Therefore it is essential to know the time required for obtaining type- O , type – specific , and
cross matched blood as well as platelet
and clotting factor availability . Response to massive
hemorrhage takes a coordinated
effort between clinicians
and the blood bank , it is helpful
to have a massive
hemorrhage protocol outlined
before an emergency occurs . Facilities
should also consider writing
and posting such a protocol in addition
to running clinical drills
on obstetric hemorrhage
scenarios .
Traditional Peripheral intravenous
catheters or central line via neck veins?? Your opinion please?? For patients
who are at risk for
bleeding or who are actively hemorrhaging the
importance of adequate
intravenous access cannot be emphasized enough. Flow through
an intravenous canula is
directly proportional to the fourth
power of the radius and inversely proportional to the length. Peripheral vein selected properlky by ward
nurse is god enough. Peripheral vein are
often preferable to central
venous access with a longer catheter . For these reasons one or more short large
bore peripheral intravenous catheters
are often preferable to central
venous access with a longer catheter
. A arterial line can be extremely
helpful during a hemorrhagic emergency , both for beat to beat monitoring
of blood pressure and for obtaining frequent
laboratory tests.
When to transfuse??? Million dollar Q!!!! Determining
when to transfuse: Determining
the point at which a patient
requires blood transfusion can
be difficult . Many factors
including vital signs ongoing
blood loss and co existing
disease should be difficult and is often
underestimated because the
blood is not always
contained in one space and because amniotic fluid is present
. As a result postpartum
hemorrhage is not clearly defined. However an estimated
blood loss greater than 500 mL for a vaginal
delivery and 1000mL for a cesarean delivery are typical
definition used to describe
postpartum hemorrhage .The American
College of Surgeons separates
the severity of hemorrhagic shock into
classes based on vital signs
and mental status . Signs and
symptoms of inadequate perfusion
due to hypovolemia have to be
searched for .and THAT include tachycardia , decreased
pulse pressure, tachypnea , decreased urine output
and an altered mental status
ranging from anxious to
lethargic . while the physiologic changes
of pregnancy can limit
the utility of this table classes lll and IV
hemorrhage indicate significant hypo perfusion and almost always require
transfusion . Historically
patients were transfused to keep
the hemoglobin concentration greater than 10 mg /dL . This
practice has been challenged by a recent study demonstrating decreased
mortality in critically ill patients who were transfused at lower
hemoglobin thresholds . On
the other end of the spectrum
hemorrhage and hypovolemic shock . Risk
factors for myocardial ischemia in this population were a hemoglobin of 6.9 g/dL
or lower systolic blood pressure
of 88 mm Hg or lower diastolic
blood pressure of 50 mm hg or
lower and a heart
rate greater than 115 beats per minute. The purpose of packed red
blood cell administration is to increase th oxygen
carrying capacity of blood. According to the American Society
of Anesthesiologists Task
Force on blood product
replacement . PRBC transfusion is rarely
indicated with a hemoglobin
level greater than 10 g/dL and is almost always indicated with a hemoglobin level
less than 6 g/dL 
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