Inadequate tissue perfusion can be a diagnosis, a sign and a symptom that one or more organs of the body are beginning to fail due to a lack of oxygenated blood either reaching an organ or fully circulating through an organ or body system.
Perfusion is the ability for blood to circulate through the body unimpeded. Within the blood, haemoglobin binds with oxygen through the act of respiration at the capillary level in the lungs. Four oxygen molecules bind to every one haemoglobin cell. If the haemoglobin cell is unable to bind at this rate or if oxygenated blood cannot freely travel to all parts of the body, a state of inadequate tissue perfusion exists.
Perfusion of the Brain
The brain needs two simple blood components to work properly. One is oxygenated blood. The other is a constant supply of glucose (blood sugar). When oxygen-rich blood does not reach the tissues of the brain, tissue death begins to occur. This is the basic premise behind cardiopulmonary resuscitation (CPR). The brain can survive four to six minutes without a circulating supply of oxygen. CPR is administered as an adjunct to help in brain damage as a consequence of a heart that isn't pumping.
Perfusion of the Heart
During a heart attack, vessels of the heart, such as the coronary arteries, can become occluded with intervascular plaques. The heart does not absorb blood through the myocardial wall. Instead, blood is pumped through the heart's own vasculature during the relaxation (diastole) period between heart beats. An occlusion of a blood vessel is known by the clinical designation "thrombus." If a cardiac plaque breaks off from one vessel and becomes lodged in another vessel, the tissue-fed oxygen-rich blood is inadequately perfused. As a result, the tissue begins to die.
Perfusion and the Diabetic Patient
In patients with diabetes mellitus, decreased tissue perfusion in the lower extremities is often a complication, especially if the diabetic has a history of staying on a regular medication. As a result, the patient has a decreased healing capacity, and injuries to the feet, cuts, ingrown toenails or footwear that is binding can lead to ulcerations that become necrotic (dead due to poor tissue perfusion) and must be amputated because of gangrenous complications.
Treating Inadequate Perfusion
Treatment for poor tissue perfusion is mostly supportive. The use of supplemental oxygen aids in decreased haemoglobin binding. Cardiopulmonary resuscitation is exercised when cardiovascular collapse threatens brain damage. Blood thinning agents are used when thrombi are suspected or when other blood clotting factors are diagnosed as a cause of decreased perfusion. And hyperbaric chamber therapy has shown success in healing ulcerative wounds in the diabetic patient, decreasing the risk of amputation.