Shock: a review of pathophysiology and management. Part II.

OBJECTIVE To review pathophysiology and management of hypovolaemic, cardiogenic and septic shock in a two part presentation. DATA SOURCES Articles and published peer-review abstracts and a review of studies reported from 1994 to 1998 and identified through a MEDLINE search of the English language literature on septic shock, cardiogenic shock and hypovolaemic shock. SUMMARY OF REVIEW The pathophysiological effects of cardiogenic and hypovolaemic shock are related predominantly to a reduction in preload and myocardial contractility, respectively, whereas the pathophysiological effects of septic shock result largely from the overwhelming production of inflammatory mediators. The excessive inflammatory response results in haemodynamic compromise and widespread tissue injury. While the understanding of the acute inflammatory reaction has improved, therapies to modulate the chemical mediators responsible for the organ dysfunction associated with this reaction have not altered mortality, and in some instances may have increased it. Treatment of septic shock is still largely supportive, using intravenous fluids and inotropic agents to provide adequate tissue perfusion while the infective lesion is managed with antibiotic therapy and surgical drainage of septic focus. CONCLUSIONS Septic shock is provoked by an excessive acute inflammatory response to an infection. Management of the shock is supportive using fluids and inotropic agents, while antibiotic therapy and surgical drainage of the septic focus take effect. Immunomodulation of the acute inflammatory response causing septic shock has not improved mortality.