Interaction between hypotension and age on adrenal crisis diagnosis.

Objective: To determine whether adrenal crisis (AC) identification may be affected by the definition of hypotension. Context: Delays in AC diagnosis can result in adverse outcomes. AC-related cardiovascular compromise may vary according to baseline blood pressure and may be associated with delayed AC detection in some patients. Design: A retrospective study of paired systolic blood pressure (sBP) measurements in hospitalized patients with primary AI (PAI). Patients: Patients with PAI and an acute illness admitted for urgent treatment between 2000 and 2017. Measurements: A comparison between sBP on hospital arrival and on discharge. Hypotension was classified as either absolute hypotension (sBP 100mg or lower) or relative hypotension (sBP over 100 mg but at least 20 mm Hg lower than discharge sBP). Results: Of 152 admissions with paired blood pressure measurements, 46 (30.3%) included a medically diagnosed AC. Absolute hypotension was found in 38 (25.0%) records, and a further 21 (13.8%) patients were classified as having relative hypotension. Patients aged 65 years and older had the lowest (14.8%, n = 8) proportion with absolute hypotension but the highest (27.8%, n = 15) with relative hypotension. Use of either absolute or relative hypotension as the criterion for AC diagnosis increased the proportion of patients with an AC by 28.3% and the proportion of patients with an AC in the oldest age group by 130%. Conclusions: Failure to detect cardiovascular compromise is common in older AI patients, may underestimate the AC rate in this group, and delay essential treatment. Relative hypotension may play a role in AC diagnosis.