How can you clinically estimate amount of blood loss preop?
Class I: <15% of blood volume lost; vital signs are normal; slight anxiety.
Class II: 15-30% of blood volume lost; pulse >100 per minute; blood pressure normal; decreased pulse pressure; tachypnea; output 20-30 ml/hour; moderate anxiety; capillary refill time increased
Class III: 30-40% of blood volume lost; pulse >120; blood pressure decreased; respiratory rate 30-40/min; output 5-15 ml/hour; anxious and confused.
Class IV: over 40% of blood volume lost; pulse >140; blood pressure very low; narrow pulse pressure; negligible urine output; confused, lethargic.