how much blood loss to become tachycardic
1 Class I Hemorrhage involves up to 15% of blood volume. 2  There is typically no change in vital signs and fluid resuscitation is not usually necessary. 3  Class II Hemorrhage involves 15-30% of total blood volume.lood loss [edit]. Hemorrhaging is broken down into four classes by the American College of Surgeons' advanced trauma life support (ATLS). 1  Class I Hemorrhage involves up to 15% of blood volume.