The importance of recognizing whewellite

An 81-year-old man was found lying on the ground outside his home. He was comatose and hypothermic. He had a severe metabolic acidosis with elevated anion and osmol gaps, and his plasma ethylene glycol level was 3180 mg/l. The urine sediment showed calcium oxalate monohydrate crystals (Figure 1). Due to prolonged exposure, the patient died despite treatment. Survival of ethylene glycol intoxication depends on the rapidity of diagnosis and treatment. If recognized, urinary calcium oxalate crystals may provide an important diagnostic clue. They exist in two forms. Best known are the envelope-shaped dihydrate crystals named weddellite after their first discovery in Antarctic Ocean sediment (Figure 2). The rod-shaped monohydrate crystals named after the British scientist William Whewell (1794-1866) are