Significant haemorrhage will cause a cascade of negative events that will lead to the demise of the patient if not urgently treated.  The pathophysiological processes that can 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 glucose is more available where needed. The patients’ respiratory rate increases to try and combat the starting effects of metabolic acidosis caused by cells which are now having to move to an anaerobic state due to lack of oxygen and nutrient supply from the diminishing blood volume. 

With further blood loss, the compensatory state of the body begins to fail. The point where this begins 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 shut down. 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. 

Management of Catastrophic Haemorrhage: 

Most external catastrophic haemorrhage is usually caused through traumatic means. The MOI and the location of the injury will determine how best to treat the wound. While getting equipment and 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/responder present while you get equipment to apply more definitive management. 

If there is catastrophic haemorrhage from a limb injury, then the flow of treatment follows; 

• Apply a Catastrophic Haemorrhage Tourniquet proximal to the site of the injury on viable tissue 

• The tourniquet needs to be tightened to the where haemorrhage completely stops 

• If tightening the tourniquet fails to stem bleeding, then apply a second tourniquet above the first 

• Do not remove the first tourniquet 

• If this fails, pack the bleeding site with haemostatic gauze and apply a dressing with direct pressure on the haemorrhage site 

• Try to pack the wound with the haemostatic gauze applying pressure to the circulatory structure where the haemorrhage is mainly coming from, for example, packing up against a haemorrhaging artery. 

• If this fails, then a rapid transfer to the nearest receiving hospital is required 

• Whilst on route, you want to continue to apply pressure and manage as best you can. Having additional staff/responders in the Ambulance where available can help support this and other ongoing management.  

If there is catastrophic haemorrhage from the head, neck, or torso, then the flow of treatment follows; 

• Apply a field dressing to the haemorrhage site 

• There are various makes and types of dressing available, but typically, those designed for catastrophic haemorrhage will be elasticated, or have a function/design where pressure is automatically placed on the haemorrhage site. 

• If this fails to stem bleeding, then apply direct pressure over the site 

• Direct pressure may have to be maintained throughout, meaning you or a colleague/responder will have to remain on managing catastrophic haemorrhage, while others manage the other elements of the Primary Survey. 

• If this fails, pack the bleeding site with haemostatic gauze and apply a fresh dressing with direct pressure 

• Try to pack the wound with the haemostatic gauze applying pressure to the circulatory structure where the haemorrhage is mainly coming from, for example, packing up against a haemorrhaging artery. 

• If this fails, apply further dressings and direct pressure 

• By applying further dressings, try to get more pressure placed on the haemorrhage site. 

• If this fails, then a rapid transfer to the nearest receiving hospital is required 

• Whilst on route, you want to continue to apply pressure and manage as best you can. Having additional staff/responders in the Ambulance where available can help support this and other ongoing management.