Shock

Shock is a circulatory failure resulting in inadequate organ perfusion - basically, if you're not getting enough oxygen to the important bits and pieces, you're probably in shock. There are lots of different causes of shock but there are four important types of shock:

• Cardiogenic shock - your heart isn't pumping efficiently enough
• Hypovolaemic shock - literally "low-volume" shock i.e. there isn't enough blood
• Septic shock - due to a blood infection
• Anaphylactic shock - a life-threatening allergic reaction

There are other types of shock but these are much rarer. Endocrine failure due to Addison's disease or hypothyroidism. Neurogenic and iatrogenic shock (in anaesthetics and with antihypertensives) can also occur.

Definition

As above - a circulatory failure resulting in inadequate organ/tissue perfusion.

Epidemiology

If you only learn one thing before you become an F1 learn to manage shock. It's common and people die from it so if we had bothered to make an "Common And Important" .jpg, it would have been specifically for this condition.

Pathophysiology

One of two thing has happened: the pump (i.e. the heart) or the peripheral circulation is in failure. Cardiogenic shock covers the first category but all the others generally fall into the "peripheral circulation failure" category. In this page, the general management of shock is outlined, assuming that there is no known cause. Since the first time you find out about shock, it's often because the BP has dropped, it's worth knowing this general management scheme.