The postperfusion syndrome is an uncommon event following open-heart surgery with extracorporeal circulation. It is associated with a young age at surgery (less than 1 year) and bypass lasting longer than 60 minutes. Luciani et al. (1997) observed the syndrome in an 18-year-old man who underwent transpulmonary patch repair of a ventricular septal defect with cardiopulmonary bypass for 50 minutes. Preoperatively, the patient exhibited a slight gait disorder and unremarkable EEG and laboratory findings. Twelve hours after surgery he developed hypotension and circulatory collapse. This was treated successfully, but 10 days after discharge the patient was admitted with findings suggesting Addison disease. He showed a worsening disturbance of gait, with ataxia and EEG abnormalities. The diagnosis of adrenoleukodystrophy was supported by MRI of the head and confirmed by increased plasma levels of very long chain saturated fatty acids. Thus, Luciani et al. (1997) concluded that this was a case of Addisonian crisis precipitated by surgery in a patient with previously unrecognized AMD.
Steroid isolation , depending on context, is the isolation of chemical matter required for chemical structure elucidation, derivitzation or degradation chemistry, biological testing, and other research needs (generally milligrams to grams, but often more  or the isolation of "analytical quantities" of the substance of interest (where the focus is on identifying and quantifying the substance (for example, in biological tissue or fluid). The amount isolated depends on the analytical method, but is generally less than one microgram.  [ page needed ] The methods of isolation to achieve the two scales of product are distinct, but include extraction , precipitation, adsorption , chromatography , and crystallization . In both cases, the isolated substance is purified to chemical homogeneity; combined separation and analytical methods, such as LC-MS , are chosen to be "orthogonal"—achieving their separations based on distinct modes of interaction between substance and isolating matrix—to detect a single species in the pure sample. Structure determination refers to the methods to determine the chemical structure of an isolated pure steroid, using an evolving array of chemical and physical methods which have included NMR and small-molecule crystallography .  : 10–19 Methods of analysis overlap both of the above areas, emphasizing analytical methods to determining if a steroid is present in a mixture and determining its quantity.