Porphyrias: implications for anaesthesia, critical care, and pain medicine

Abstract

The porphyrias are a heterogeneous group of inherited disorders of haem biosynthesis. The name porphyria is derived from the Greek word for purple, ‘porphyros’. This was the name given to the purple compound formed when blood was treated with concentrated sulphuric acid; the disease was probably named porphyria due to the red discolouration of urine in affected patients. Multiple classification systems exist; the most relevant to anaesthetists is acute and nonacute (Table 1). All acute porphyrias have the potential to develop acute neurovisceral crises. Precipitating factors are commonly encountered in the perioperative period; therefore, anaesthetists must be aware of the triggers and the management of an acute crisis. Non-acute porphyrias do not deteriorate into acute crises, are less relevant for anaesthetists, and will not be mentioned further in this article.