The literal definition of perfusion is flowing over or through. As it relates to the body, perfusion is the flow of blood through the organs. This flow is critical for sustaining life because when operating properly, this is the system that transports oxygen throughout the body and removes wastes, preventing them from accumulating in the body. However, when this system is not operating properly due to illness or injury, the body becomes distressed because it is not receiving enough oxygen. It then shunts the blood to the core of the body where the vital organs are located. Many of the early signs of poor perfusion are exhibited through the skin. It is important to find the cause of the poor perfusion because as the organs are deprived of oxygen they will begin to shut down, resulting in death.
Capillary Refill Time
The rate at which blood refills the capillary beds is a quick and easy test to determine perfusion status. Use your thumb to briefly depress an area of skin that is easily accessible, the arm works well. When you remove your thumb the area that was depressed will be blanched, because you have forced the blood out of the capillaries. Time how long it takes for the blood to return and fill the blanched space. Good perfusion is indicated by a capillary refill time of two to three seconds. Be aware that temperature greatly affects blood flow to the skin so this method can inaccurate if performed in extreme temperatures. Other signs of poor perfusion related to the skin can be the colour, temperature and condition.
Since half of the job of perfusion is to rid the body of wastes, as perfusion breaks down wastes begin to build up. The body reacts to this build-up by trying to rid itself of the toxins. This results in nausea and vomiting. The emesis, or vomit, should be checked for blood since this can indicate internal bleeding.
An altered mental status is an indicator of poor perfusion, because the brain is the most hypoxic-sensitive organ in the body. The brain can only last for six minutes without oxygen before brain death begins to occur. Confusion, anxiety and restlessness are early signs that the brain is not being perfused properly; while loss of consciousness and seizures are late signs.