Some science behind the scenes
It is helpful to look at haemorrhaging within the four classes recognised by the medical profession:
- Class I Hemorrhage involves up to 15% of blood volume. There is typically no change in vital signs and fluid resuscitation is not usually necessary. Typically, a healthy person can endure a loss of 10–15% of the total blood volume without serious medical difficulties.
- Class II Hemorrhage involves 15-30% of total blood volume. A patient is often tachycardic (rapid heart beat) with a narrowing of the difference between the systolic and diastolic blood pressures. The body attempts to compensate with peripheral vasoconstriction. Skin may start to look pale and be cool to the touch.
- Class III Hemorrhage involves loss of 30-40% of circulating blood volume. The patient's blood pressure drops, the heart rate increases, peripheral hypoperfusion (shock), such as capillary refill worsens, and the mental status worsens. And it is at this point that spiritual experiences start to occur.
- Class IV Hemorrhage involves loss of >40% of circulating blood volume. The limit of the body's compensation is reached and aggressive resuscitation is required to prevent death. At this point people may get Near Death Experiences, again initially brought on by the hypoxia, but as at this stage so many other complications will have arisen it may also be caused by cardiac arrest.