Shock

Acute circulatory failure with inadequate or inappropriately distributed tissue perfusion for aerobic cellular respiration, resulting in generalised hypoxia and/or an inability of the cells to utilise oxygen

Recognising shock

Effects of shock

Causes of shock

Pulse pressure is reduced - mean arterial pressure may be maintained

Reduced urine output

Pulse is weak and rapid

Confusion, weakness, collapse and coma

Skin is pale, cold, sweaty and vasoconstricted

May be linked to the inflammatory response

Check capillary refill time - earliest & most accurate sign of shock

Prolonged hypotension which can lead to life threatening organ failure after recovery from the acute event

Distributive shock - septic shock, anaphylactic shock, neurogenic shock

Anaemic shock - not enough oxygen carrying capacity

Cardiogenic shock - heart isn't pumping

Cytotoxic shock - cells poisoned

Hypovolaemic shock - low blood volume

Hypovolaemic shock

Loss of blood due to - acute GI bleeding, trauma, peri/post-operative, splenic rupture

Loss of fluid - dehydration, burns, pancreatitis

Can be secondary to haemorrhage shock

Cardiogenic shock - heart doesn't pump

Acute MI

Fluid overload

Pulmonary embolism - flow of blood to lungs is blocked

Myocarditis - inflammation of the muscle itself

Cardiac tamponade - blood in pericardial sack placing pressure on heart thereby limiting cardiac output

Septic shock

Sepsis exists when a systemic inflammatory response is associated with an infection

Septic shock exists when sepsis is complicated by persistent hypotension that is unresponsive to fluid resuscitation

Referred to as a distributive shock

Anaphylatic shock

Massive release of histamine and other vasoactive mediators causing haemodynamic collapse

Accompanied by breathlessness and wheeze (due to bronchospasm)

Intense allergic reaction

Clinical Presentation

Cardiogenic shock

Septic shock

Hypovolaemic shock

Anaphylatic shock

Tachycardia - narrow pulse pressure and weak pulse

Sweating

Increased sympathetic tone

BP may be maintained initially but later hypotension

Inadequate tissue perfusion

Bradycardia

Skin: cold, pale, clammy, slate-grey

Brain: drowsiness and confusion

Raised jugular venous pressure (JVP)

Gallop rhythm

Signs of myocardial failure

Basal crackles and pulmonary oedema

Nausea and vomiting

Vasodilation with warm peripheries

Pyrexia and rigors

Bounding pulse

Low BP

Tachycardia

Warm peripheries

Bronchospasm

Signs of profound vasodilation

Pulmonary oedema

Treatment

ABC

B - breathing (give 100% O2) and correct immediately life threatening problems e.g. congestive heart failure, bronchospasm & tension pneumothorax

C - circulation

  • Establish secure IV access
  • Give fluid quickly and blood if acute blood loss
  • Ensure haemostats i.e. stop bleeding

A - airway (ensure patency)