Sun28November0440PM 11

A 24-year-old man is admitted to the Emergency department following blunt force trauma to his chest and abdomen by a car whilst cycling.

He appears to be stable with observations of a blood pressure of 115/78 mmHg, heart rate 82 beats per minute, a respiratory rate of 20 breaths per minute and a capillary refill time of 2 seconds. He is normally fit and well. He has not yet had intravenous fluid resuscitation.

Which of the following would be most suitable at indicating that there may be a concealed haemorrhage?

(Please select 1 option)

Arterial blood gases Incorrect answer selected

Central venous pressure

Orthostatic hypotension This is the correct answer

Urinary output

Haemoglobin

Explanation

The clinical signs suggest that less than 15% of circulating blood volume has been lost. The blood pressure and central venous pressure are poor.

The Advanced Trauma Life Support (ATLS) classification of class 1 haemorrhagic shock (blood loss up to 15%) is as follows:

<750 ml of blood loss

Minimal tachycardia

No changes in blood pressure, RR or pulse pressure

Fluid replacement normally not required as it will be restored in 24 hours, but in trauma correct

Urine output is usually unaffected.

Orthostatic or postural hypotension is a relatively early sign of concealed haemorrhage. It is defined as a fall in systolic blood pressure of more than 20 mmHg within three minutes of standing from a supine position. If a patient is unable to stand, then a head-up tilt of 600 will establish a degree of orthostatic hypotension. When there is inadequate intravascular volume, autonomic dysfunction, reduced venous return, or inability of the heart to increase its rate or stroke volume, orthostatic hypotension may result.

In the absence of hypovolaemia the presence of orthostatic hypotension might suggest autonomic dysfunction.

The haemoglobin would not have changed significantly so early after a relatively minor bleed. However, aggressive fluid resuscitation might cause a dilutional anaemia and coagulopathy. A blood gas is this patient is unlikely to be helpful, but changes in bicarbonate precede changes in pH and cardiac output with greater degrees of haemorrhage. The measurement of central venous pressure is notoriously unreliable.

Answer Statistics

1

14%

2

2%

3

62%

4

14%

5

10%

Times answered: 267