Introduction

Shock is a systemic disorder affecting multiple organ systems. Its early recognition and prompt treatment are very important as there is a direct correlation between the duration and severity of tissue hypoperfusion and poor outcome. This chapter describes the pathophysiology of haemorrhagic and septic shock, early diagnosis and principles of effective management.

Definition and mechanism of shock

Shock is a state of compromised tissue perfusion that causes cellular hypoxia. It is defined as a syndrome initiated by acute hypoperfusion leading to tissue hypoxia and vital organ dysfunction. During shock, perfusion is insufficient to meet the metabolic demands of the tissues and anaerobic metabolism occurs. This is unsustainable and, if not corrected, will progress to cellular dysfunction, cell death and end organ damage. The progressive chain of events that occurs as shock develops is summarised in Figure 16.1.

Recognition of shock

Prompt stabilisation of the woman's condition and treatment of the underlying cause of the shock can avoid the rapidly spiralling deterioration that leads to cell damage and, ultimately, death. The recognition of shock is clinical and depends on identification of the cluster of subtle signs associated with the development of tissue hypoxia and dysfunction. Tachypnoea and tachycardia are often early signs of shock, followed by hypotension and poor urine output. Only once shock has progressed some way will the patient also show the classic picture of pale, clammy skin, cool peripheries and an altered level of consciousness.