‘Just a sharp scratch’: permanent radial, median and ulnar neuropathy following diagnostic venepuncture

Abstract

An 82-year-old woman was admitted to hospital with acute left ventricular failure following a recent myocardial infarction for which she had been commenced on clopidogrel. An uneventful venepuncture in her left antecubital fossa yielded a normal full blood count and coagulation profile. Diuretics were commenced to which she responded well. Five days later she described pain, swelling and bruising of her left forearm with numbness over her thumb, index and middle fingers. Prophylactic low molecular weight heparin was discontinued and the arm elevated. Nine days later she was unable to move her left hand. Bruising extended from the shoulder to the hand with swelling distal to the antecubital fossa (Figures 1 and 2). Woody subcutaneous oedema was present around the antecubital fossa with forearm tenderness. The radial pulse was present with good capillary circulation in all fingers. Neurological examination revealed complete wrist drop, minimal finger flexion and no small muscle function of the hand. The dorsal aspect of the forearm and hand were hypersensitive, with numbness over the volar aspect of the thumb, index and middle fingers. These findings were consistent with an ischaemic neuropathy of the median, radial and ulnar nerves as a result of compartment syndrome, secondary to a compressive haematoma at the antecubital fossa following venepuncture. Surgery to relieve compartment pressures at this stage was thought to provide little chance of recovery, with the additional risk of supervening infection. Initial treatment was therefore conservative consisting of physiotherapy, vitamin B and gabapentine. An ultrasound scan confirmed the presence of a haematoma occupying the entire flexor compartment of the forearm. Nerve conduction studies revealed completely absent sensory potentials, with motor potentials 1%, 30% and 60% of normal in the radial, median and ulnar nerves respectively. This confirmed a severe subtotal axonotmesis of the radial nerve with partial axonal injury to the median and ulnar nerves. The prognosis was one of permanent major neurological deficit and despite intensive hand physiotherapy there was little functional recovery 1 year later.