100 Cases in Clinical Medicine

CASE 100: PAIN IN THE LEG

History

A 22-year-old woman is admitted to hospital with a painful left leg. She uses intravenous
drugs and injects into veins in the arms and the groins. The left leg has become swollen
and painful over the last week. She has had two previous admissions to hospital within
the last 6 months, once for an overdose of heroin and once for an infection in the left arm.
She smokes 20 cigarettes daily and drinks up to 40 units of alcohol per week.

Examination

Her pulse is 84/min and regular. Her blood pressure is 124/74 mmHg. Her temperature is
37.2°C. The heart sounds are normal and there are no abnormal findings on examination
of the respiratory system. She has a swollen left calf with some local tenderness. There are
puncture sites in both groins but no obvious sepsis.

Normal

Haemoglobin 12.0 g/dL 11.7–15.7 g/dL

White cell count 10.8% 109 /L 3.5–11.0% 109 /L

Platelets 154 % 109 /L 150–440% 109 /L

Sodium 137 mmol/L 135–145 mmol/L

Potassium 3.8 mmol/L 3.5–5.0 mmol/L

Urea 3.7 mmol/L 2.5–6.7 mmol/L

Creatinine 74 &mol/L 70–120&mol/L

Ultrasound of left leg: venous thrombus extending into the left femoral vein

INVESTIGATIONS

Venous access is difficult but a line is inserted in the right arm and she is treated with sub-
cutaneous low-molecular-weight heparin, intravenous vitamins and benzodiazepines, and
a methadone-replacement regime. On the fourth day of her admission she became much
more unwell.

Further examination

Her pulse is 112 per minute and regular. Her blood pressure is 88/50 mmHg although she
seems warm and well perused. The respiratory rate is18/min, jugular venous pressure is
not raised, there are no new heart murmurs and oxygen saturation is 97 per cent on room
air. Her temperature is 37.6°C.