Causes and Types of Shock

Shock is a life threatening condition that happens when the arterial blood flow and oxygen delivery to the cells and tissues becomes inadequate. Shock is commonly associated with three different events, the heart becomes ineffective in pumping blood, the amount of blood significantly decreases such as trauma related or blood vessels excessively dilate.

Shock can be divided into four categories obstructive, cardiogenic, distributive and hypovolemic. There are several different factors relating to each category of shock however there are also a few things that all the types of shock have in common.

Hypovolemic shock is when the volume of cellular fluid is significantly diminished because of loss of blood or plasma. Hypovolemic shock can develop because of trauma resulting in massive blood loss, during surgery or after giving birth. Hypovolemic shock can also develop because of disorders in which fluid losses exceed the intake of fluid or severe burns over a person's body.

Distributive shock happens when the fluid circulation is not adequate for effective tissue perfusion, vasodilatation is a common factor in distributive shock. In vasodilatation the central blood flow is decreased because of the peripheral vascular system exceed regular capacity. There are three types of distributive shock. The most common type is anaphylactic shock, however there are also neurogenic and septic shock.

Anaphylactic shock happens because of a severe allergic reaction due to a person's exposure to a substance in which they are extremely sensitive. The exposure causes redistribution of intravascular fluid from the arterial circulation to venous or capillaries. Anaphylactic shock can result in airway constriction, swelling of tissues and other allergic responses such as hives.

Neurogenic shock develops when there is a injury to the vasomotor center in the brain's medulla or to the peripheral nerves that extend from the spinal cord to the blood vessels. Neurogenic shock can develop because of opioids overdose, head injuries or spinal cord injuries. In neurogenic shock the heart is not able to fill properly resulting in decreased cardiac output, tissue perfusion is decreased and cells are therefore deprived of oxygen.

Septic shock is associated with high grade bacterial infections. Septic shock commonly occurs when bacteria gets into the blood supply. People who develop septic shock usually present with fever, flushed skin and bounding rapid pulse. After septic shock progresses patients will commonly have the same reactions as other shock patients such as cold and pale skin and low blood pressure.

Obstructive shock happens when the heart or large blood vessels are compressed. The squeezing of the heart or large vessels compromises the heart's ability to pump adequate blood volume entering or existing the heart. Any traumatic condition that fills the thoracic cavity with fluid, tissue or air can lead to obstructive shock such as cardiac tamponade which is an increase of fluid or blood in the pericardial sac. This compression causes the heart and large vessels to struggle to pump sufficiently and can be life threatening without immediate emergency treatment.

Cardiogenic shock develops when heart contractions are ineffective which significantly reduces the cardiac output. Heart failure after a heart attack is the leading factor of cardiogenic shock. Cardiac dysrhythmia can also result in cardiogenic shock.

If you are around anyone that you think may be going into shock it is imperative that you seek emergency medical care for them as soon as possible.

References:

www.spiritus-temporis.com/shock/types-of-shock.html
www.essortment.com/all/shockwhatcause_piu.htm
www.medicinenet.com/shock/article.htm