ABSTRACT
Shock is a pathophysiological entity characterised by failure of the cardiovascular system to provide adequate tissue perfusion. Distributive shock is mediated by the systemic release of pro-inflammatory cytokines in conditions such as sepsis, pancreatitis and anaphylaxis, resulting in increased capillary permeability and arteriolar vasodilatation. If it is not rapidly corrected, this process can culminate in multiple organ failure and death. Urgent surgical intervention may be required for a number of causes of shock, including type A aortic dissection, ruptured abdominal aortic aneurysm, acute valvular regurgitation, acute ventricular septum or wall rupture, ruptured ectopic pregnancy and perforated intra-abdominal viscus. Other forms of shock are associated with cool peripheries, prolonged capillary refill time and a weak thready pulse. Dry mucous membranes and reduced skin turgor occur with hypovolaemia. In particular, echocardiography may reveal ventricular wall motion abnormalities associated with myocardial ischaemia or dysfunction, cardiac tamponade, right ventricular strain associated with massive pulmonary embolism, acute valvular regurgitation or ventricular septal rupture.
