2nd August 2023

Shocked Patient

Definition

‘Shock’ can be defined as circulatory failure resulting in hypoperfusion of the tissues and an inadequate level of oxygen delivery to meet the metabolic requirements of tissues. Prolonged hypoperfusion can cause derangement in cell processes, ultimately leading to cell necrosis and end-organ failure. Early recognition and treatment of a shocked patient is essential.

Causes

Two main categories can lead to circulatory failure or ‘shock’. These can broadly be categorised as low flow volume or low arteriolar resistance (vasodilation). Based on the two categories, there are different conditions and causes that can lead to both (table 1).

Table 1: Two main categories of conditions that can lead to circulatory failure or ‘shock’ with examples of the main causes in each category respectively.

Clinical Features

Clinical features of shock are usually dependent on the primary pathophysiology or underlying cause. Patients who present due to low flow often have features such as cold peripheries, absent or weak peripheral pulses and evidence of low cardiac output. This can include features such as a narrowed pulse pressure.

Conversely, patients who present with shock from vasodilatation tend to have warm peripheries, bounding pulses and often features of high cardiac output. This can include features such as hypotension with wide pulse pressure, raised temperature and general distress.

Investigations and Management

The main features of ‘shock’ include hypotension, tachycardia, and evidence of end organ dysfunction. This can include poor kidney function, deranged coagulation, respiratory distress such as increasing oxygen requirements and liver derangement. The clinical presentation and observations will be dependent on the underlying causative factor.

Management of shock involves rapid identification of the underlying cause to be able to administer appropriate treatment.