Oxygen-carrying v. non-oxygen-carrying colloidal blood substitutes in schock

Loss of more than 10-15 per cent of the circulating blood causes a corresponding fall in filling pressure and a marked reduction in minute volume. In order to combat a fall in the minute volume, catecholamines are liberated, the stimulating components of these cause a rise in vessel tone. In spite of the blood volume being reduced by blood loss, filling pressure and minute volume are restored by compensating mechanisms as long as the volume lost is not enough to exceed the autoregulative capacity. Even with a blood loss of 10-15 per cent, full compensation is not achieved without replenishing the blood volume unless the fluid lost from the vascular bed is less than I0 per cent of the total.…