Blood Transfusion in
Acute Trauma
Prof. W. O. Mwanda
Background
• Use of blood and blood
components/products- save life -reduce
risks of transfusion transmissible diseases,
most particularly the transmission of HIV
and other infectious agents.
• Red cells ,and plasma a number of clinical
circumstances.
• Decision for red cell transfusion should
not be based on haemoglobin levels
alone, consider the clinical circumstances
of the patient.
• No precise formula to be used in the
decision to transfuse particularly red
cells.
• There is no uniform formula to be used in
the decision to transfuse red cells. some
clinical and laboratory parameters that
assist the doctor in the decision to
transfuse.
• There are surgical situations, which
require transfusion.
• Rule1, the maintenance of adequate
oxygen delivery is the goal of red cell
transfusions.
Functions associated with oxygen delivery
• Ventilation
• Alveolar-capillary diffusion
• Haemoglobin O2 binding
• Haemoglobin level
• Blood flow
• Cardiac output
• Stroke volume
• Heart rate
• Peripheral resistance
• Oxygen extraction
Haemoglobin O2 affinity
• Cellular respiration
• During stress and disease states, the
ability for considerable compensation by
one function of the oxygen delivery chain
to overcome deficiencies of another.
• Increased oxygen extraction
• Decreased haemoglobin oxygen
affinity.
• These compensatory mechanisms take
time to develop to their full efficiency.
• The patient may not recognize a
developing anaemia until it becomes
severe.
ACUTE FALL IN HAEMOGLOBIN
• Does not allow time for compensatory
mechanisms to become fully effective.
oxygen delivery is less and tissue
anoxia may occur at higher
haemoglobin levels
Massive Transfusion
• Transfusion equal to or exceeding the
patient’s blood volume within a 24-hour
period. In the adult male who weighs 70
kg, this translates to an estimated
replacement of 4-5 litres of blood, or
transfusion of 16-20 units of packed red
blood cells (RBCs).
• Consequently, massive blood loss is the
loss of between 30 and 50% of total
blood volume.
• This definition is more useful in the clinical
setting because amounts of blood loss can be
tied to clinical signs and symptoms and the
development of shock.
• severe haemorrhage as a rate of blood loss
>150ml/min, which could lead to the loss of
one half of the victim’s blood volume within
20 minutes. These patients are relatively easy
to recognize from their obvious signs of shock,
patients with less severe haemorrhage are more
difficult to define on clinical grounds.
• Blood loss and haemorrhagic shock
should be classified for the purposes of
treatment as follows:
Class 1 Haemorrhage
• Blood loss is <15% of total blood
volume. The common clinical
manifestations include normal or
slightly increased pulse rate, normal
blood pressure and pulse pressure, and
no changes in signs of tissues
perfusion. Volume losses are typically
restored from extracellular fluid
resources.
Class II Haemorrhage
Blood loss 15-30% of total blood volume. In
this situation, the heart rate is increased and
systolic blood pressure is typically normal,
but pulse pressure decreases in response to
vasoconstriction and tachycardia. A drop in
blood pressure can be seen with change in
posture from supine to seated (positive tilt
test). Capillary refill may be delayed,
respiratory rate may be increased, and
patients may demonstrate some signs of
anxiety as a result of decreased cerebral
perfusion.
Class III Haemorrhage
• Blood loss of 30-40% of total blood
volume. Symptoms include
tachycardia, decreased systolic blood
pressure and pulse pressure, delayed
capillary refill, and a progressively
increasing respiratory rate. Urine
output may become decreased and the
patient may become confused at this
level.
Class IV haemorrhage:
Blood loss >40% of total blood volume. Clinical signs are those
of shock: tachycardia, hypotension, oliguria, and lethargy or
coma. Patients with Class IV haemorrhage are those who fall
into the massive transfusion category.
Massive transfusion volume guideline for those aged less than 20 years
Patient’s Age in years
Units transfused
Less 2
2.0
2–4
3.0
4 –6
4.0
6–8
5.5
8 – 10
5.5
10 – 12
6.5
12 – 14
8.0
14 – 16
9.0
16 – 18
10.5
18
12.0
Thank you