Hypotension, Adrenal Crisis and Age

Context:

Adrenal crises (AC) are episodes of severeadrenal insufficiency (AI) with hypotension.They cause morbidity and mortality inpatients with Addison’s disease [primaryadrenal insufficiency (PAI)]. AC is defined byhypotension and symptoms and signs of AI,which includes confusion, acute abdominalsymptoms, and electrolyte abnormalities.Misclassification of AC episodes is acommon problem, particularly in patientswith hypertension whose relativehypotension may go undetected.This phenomenon is of particularimportance in older AI patients, whose riskof poorer outcomes is compounded byunder-recognition of cardiovascularcompromise and increased burden of co-morbidities

Objective

To determine the effect of utilising relativehypotension (sBP decrease greater than20mmHg) to define an AC diagnosis inestimating the true incidence of episodes,particularly in estimating age-specific ACincidence.

Methods

A retrospective study of paired systolicblood pressure (sBP) measurements inhospitalised patients with PAI, pre and posttreatment of AI/AC. Patients included foranalysis were those with PAI and an acute medical illness admitted to a large regionalhospital for urgent treatment between 2000and 2017. Measurements included acomparison between sBP on arrival athospital and on discharge. Hypotensionwas classified as either absolutehypotension (sBP 100mg or lower) orrelative hypotension (sBP over 100mg butat least 20mmHg lower than dischargesBP).

Results

There were 152 admissions with pairedblood pressure measurements. Of these,46 (30.3%) included a record of a medicallydiagnosed AC. Absolute hypotension wasfound in 38 (25.0%) records, and a further21 (13.8%) patients were classified ashaving relative hypotension. Patients aged65 years and older had the lowest (14.8%,n=8) proportion with absolute hypotensionbut the highest (27.8%, n=15) with relativehypotension. Use of absolute and relativehypotension as the criterion for ACdiagnosis increased the proportion ofpatients with an AC by 28.3% and theproportion of patients with an AC in theoldest age group by 130%.

Conclusions

Using absolute hypotension (sBP <100mmHg) to define AC fails to detectcardiovascular compromise in a subgroupof older AI patients, underestimates the truerate of ACs in this group, and may result indelays in essential treatment. Relativehypotension should be assessed in all illpatients with AI.

Affiliations

School of Medicine, Sydney, The University of Notre Dame,Darlinghurst, Australia
Thomas Goubar
Louise Rushworth

John Hunter Hospital, New Lambton, Australia
Cecilia Ostman
Shaun McGrath

Endocrine and Metabolic Unit, Royal Adelaide Hospital andUniversity of Adelaide, North Terrace, Adelaide, Australia
David J Torpy