Delayed awakening from general anaesthesia in a patient with Hunter syndrome

Hunter syndrome is one of a heterogeneous group of recessively inherited mucopolysaccharide storage diseases (MPS) with similar biochemical defects manifested by impairments in mucopolysaccharide catabolism with variable but progressive clinical courses. Abnormal accumulation and deposition of mucopolysaccharides in the tissue of several organs to numerous anatomical, musculoskeletal and neurological abnormalities which are known to complicate anaesthetic and airway management. Hunter syndrome has a wide variance of clinical phenotypes ranging from mild to severe. We present a patient having physical and neurological features consistent with a severe clinical presentation of Hunter syndrome (MPS, Type II). Following a seemingly uneventful intraoperative anaesthetic course including isoflurane, nitrous oxide and fentanyl (0.93 microgram.kg-1), resumption of spontaneous ventilation and return to consciousness were delayed until intravenous naloxone (200 micrograms) was administered 110 min after the opioid administration. The cause of delayed recovery from anaesthesia in this patient is unknown.