A. < 15% - Explanation
STAGES OF HYPOVOLAEMIC SHOCK
For adults, the clinical staging relating to loss of blood volume can be classified as:
| Stage 1 | Stage 2 | Stage 3 | Stage 4 | |
| Blood loss | 10-15% | 15-30% | 30-40% | Over 40% |
| Blood pressure | Normal | Postural hypotension | Hypotension | Marked hypotension |
| Heart rate | Normal | Slight tachycardia (>100 bpm) | Tachycardia (>120 bpm) | Extreme tachycardia (>140 bpm) |
| Respiratory rate | Normal | Increased (>20) | Tachypnoea (>30) | Extreme tachypnoea |
| Mental status | Normal | Slight anxiety, restless | Altered, confused | Decreased consciousness, lethargy, or coma |
| Urine output | Normal | 20-30 mL/hour | Less than 20 mL/hour | No urine output |
It may be difficult to remember all these values and features of stages of hypovolaemic
shock. The best suggestion is to just memorise the heart rate and base your anwer on
that. The examination questions usually would give a history of blood loss and the
patient’s heart rate. With the heart rate alone, you should be able to tell which clinical
stage he is in. You would also need to memorise the amount of blood loss in each
stage e.g. 30-40% in stage 3.
