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Overview :
The American College of Surgeons (ACS) has classified blood
loss into 4 groups based on the amount of blood loss and the patient's
physiologic response.
Parameters:
(1) volume of blood loss in mL
(2) blood loss as percent of total blood volume
(3) pulse in beats per minute
(4) blood pressure in mm Hg
(5) pulse pressure in mm Hg
(6) capillary refill test
(7) respirations per minute
(8) urine output in mL per hour
(9) mental status
where:
•
Pulse pressure = (systolic blood pressure) – (diastolic blood pressure)
•
The hemoglobin is often to used to guide the estimate of blood loss but may not
be available.
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Parameter
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Class I
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Class II
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Class III
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Class IV
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blood loss in mL
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<= 750 mL
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750 – 1,500 mL
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1,500 – 2,000 mL
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>= 2,000 mL
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blood loss as percent total blood volume
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<= 15%
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15 – 30%
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30 – 40%
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>= 40%
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pulse
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> 100
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> 100
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> 120
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>= 140
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blood pressure
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normal
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normal
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decreased
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decreased
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pulse pressure
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normal or increased
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decreased
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decreased
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decreased
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capillary refill
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normal
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delayed
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delayed
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delayed
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respirations
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14 – 20
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20 – 30
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30 – 40
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> 35
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urine output
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>= 30 mL/h
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20 – 30 mL/h
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5 – 10 mL/h
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minimal
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mental status
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slightly anxious
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mildly anxious
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anxious and
confused
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confused and
lethargic
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Intravenous replacement solutions:
(1) crystalloid: sufficient for Classes I and II
(2) crystalloid and blood (in ratio of 3:1): for Classes III
and IV
Limitations:
• Some of the
physiologic responses to hypovolemia can be affected by injury, concurrent
disease or drugs.
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