Surgery - Circulation: Classification of Haemorrhagic Shock

Class 1 Shock

Blood pressure: Systolic blood pressure is unchanged and diastolic blood pressure is unchanged.

Pulse: The pulse is high-normal in rate and normal in volume.

Capillary refill time: Capillary refill time is normal.

Respiratory rate: Respiratory rate is normal.

Urine output: Urine output remains greater than 30 mL/hour.

Extremities: The extremities retain a normal colour.

Complexion: The complexion remains normal.

Mental state: The patient remains alert.

Blood loss: Blood loss is less than 15%, approximately 750 mL.

A useful tennis analogy is “love-fifteen.”

Class 2 Shock

Blood pressure: Systolic blood pressure is usually normal, while diastolic blood pressure may be raised.

Pulse: The pulse rate is approximately 100–120 beats/minute, with a generally normal pulse volume.

Capillary refill time: Capillary refill is slow, usually taking more than 2 seconds.

Respiratory rate: Tachypnoea develops.

Urine output: Urine output falls to approximately 20–30 mL/hour.

Extremities: The extremities become pale.

Complexion: The patient appears pale.

Mental state: The patient may become anxious.

Blood loss: Blood loss is approximately 15–30%, corresponding to around 800–1500 mL.

A useful tennis analogy is “fifteen-thirty.”

Class 3 Shock

Blood pressure: Both systolic and diastolic blood pressure are reduced.

Pulse: The pulse is greater than 120 beats/minute and becomes thready.

Capillary refill time: Capillary refill remains slow, usually more than 2 seconds.

Respiratory rate: The respiratory rate is greater than 20 breaths/minute.

Urine output: Urine output falls to approximately 10–20 mL/hour.

Extremities: The extremities are pale.

Complexion: The patient appears pale.

Mental state: The patient may become aggressive or drowsy.

Blood loss: Blood loss is approximately 30–40%, corresponding to around 1500–2000 mL.

A useful tennis analogy is “thirty-forty.”

Class 4 Shock

Blood pressure: Systolic blood pressure is very low, while diastolic blood pressure is very low or may be unrecordable.

Pulse: The pulse is greater than 120 beats/minute and is very thready.

Capillary refill time: Capillary refill may be undetectable.

Respiratory rate: The respiratory rate is greater than 20 breaths/minute.

Urine output: Urine output falls to approximately 0–10 mL/hour.

Extremities: The extremities are pale and clammy.

Complexion: The patient may appear ashen.

Mental state: The patient becomes drowsy or confused.

Blood loss: Blood loss exceeds 40%, corresponding to more than 2000 mL.

A useful tennis analogy is “game over.”