Pyroglutamic acidosis has been the subject of several SAQs, which - some might say- places it upon a pedestal of undeserved importance in the mind of the trainee. It is a ridiculous rare problem, which occurs due to glutathione depletion in patients who are already glutathione-depleted, and who receive flucloxacillin or vigabatrin together with paracetamol.
SAQs involving this disorder have appeared every year for the last 4 years.
A much more detailed exploration of this ridiculously rare disorder is carried out in a dedicated chapter on pyroglutamic acidosis. The three-line answer above is the expected minimum.
The diagnosis of pyroglutamic acidosis depends upon the detection of 5-oxoproline; this is either a urinary or a serum level. Usually, an adult ICU needs to send this sample to a paediatric centre, where detailed analysis of weird metabolites is more likely to be available.
Management consists of
This was asked about in Question 23 from the second paper of 2014.
Depletion of glutathione
Dysfunction of 5-oxoprolinase
Diminished 5-oxoproline clearance
The college also like to include old age as a risk factor. This association is known from case reports, as it seems most of the reported-on patients are elderly, but the mechanism is not well explained. Likely there are simultaneous issues of malnutrition, decreased hepatic glutathione reserves, diminished enzyme activity, and poor renal clearance.
Dempsey GA Lyall HJ, Corke CF, Scheinkestel CD. Pyroglutamic acidemia: a cause of high anion gap metabolic acidosis. Crit Care Med. 2000Jun;28(6):1803-7.
Duewall, Jennifer L., et al. "5-Oxoproline (pyroglutamic) acidosis associated with chronic acetaminophen use." Proceedings (Baylor University. Medical Center) 23.1 (2010): 19.
Akhilesh Kumar and Anand K. Bachhawat Pyroglutamic acid: throwing light on a lightly studied metabolite ,SPECIAL SECTION: CHEMISTRY AND BIOLOGY. CURRENT SCIENCE, VOL. 102, NO. 2, 25 JANUARY 2012. 288
Amer, H. "Flucloxacillin/paracetamol interaction Metabolic acidosis in elderly patients: 2 case." Reactions 1373 (2011): 15.