Significant haemorrhage will cause a cascade of negative events that will lead to the demise of the patient if not urgently treated. The processes that follow:
Less blood will be returned to the heart meaning the volume pumped will be reduced. A fall in blood pressure is sensed by baroreceptors and the body initiates a sympathetic response, causing vasoconstriction, tachycardia, sweating and pupil dilation. With continued haemorrhage and vasoconstriction, extremities cool, and capillary refill time lengthens. The kidneys retain sodium to draw fluid from urine to keep in circulation, and secretion of cortisol inhibits the function of insulin, which allows blood sugar levels to rise so sugar is available where needed. The patients’ respiratory rate increases to help combat the effects of metabolic acidosis caused by cells which are now working in an anaerobic state.
With further blood loss, the compensatory state of the body begins to fail. The point where this begins to fail depends on the age, fitness, health, comorbidities, and other surrounding factors of the patient. Organs that rely on strictly required levels of blood supply begin to fail. As this continues the kidneys soon fail followed by the brain, decreasing urine output and conscious level. For the reasons above, early management of catastrophic haemorrhage is vitally important and why it is first on the list of the Primary survey assessment.
The majority of external catastrophic haemorrhage is usually caused through traumatic means. The MOI and the location of the injury will help determine how best to treat the wound. While implementing treatment it is important to try and reduce blood loss by getting direct pressure on the wound site. This may be done via a colleague/patient/bystander/other emergency service staff present if possible.
If there is catastrophic haemorrhage from a limb injury, then the flow of treatment follows;
If there is catastrophic haemorrhage from the head, neck, or torso, then the flow of treatment follows;