Related Experiment Video
Updated: Feb 9, 2026

Point-of-Care Ultrasound: A Review of Ultrasound Parameters for Predicting Difficult Airways
Published on: April 7, 2023
Saline suppression test parameters may predict bilateral subtypes of primary aldosteronism
Hikaru Hashimura1, Jimmy Shen1,2, Peter J Fuller1,2
1Department of Endocrinology, Monash Health, Clayton, Vic., Australia.
Background:
The saline suppression test (SST) serves to confirm the diagnosis of primary aldosteronism (PA) whilst adrenal vein sampling (AVS) is used to determine whether the aldosterone hypersecretion is unilateral or bilateral. An accurate prediction of bilateral PA based on SST results could reduce the need for AVS.
Aim:
We sought to identify SST parameters that reliably predict bilateral PA.
Methods:
The results from 121 patients undergoing SSTs at Monash Health from January 2010 to January 2018 including screening blood tests, imaging, AVS and histopathology results were evaluated. Patients were subtyped into unilateral or bilateral PA based on AVS and surgical outcomes.
Results:
Of 113 patients with confirmed PA, 33 had unilateral disease whilst 42 had bilateral disease. In those with bilateral disease, plasma aldosterone concentration (PAC) was significantly lower post-SST, together with a significant fall in the aldosterone-renin ratio (ARR). The combination of PAC < 300 pmol/L and a reduction in ARR post-SST provided 96.8% specificity in predicting bilateral disease. Eighteen of 39 patients (49%) with bilateral PA could have avoided AVS using these criteria.
Conclusion:
A combination of PAC < 300 pmol/L and a lower ARR post-SST could reliably predict bilateral PA. An independent cohort will be needed to validate these findings.
Related Concept Videos
Predicting Molecular Geometry
Wave Parameters
Prediction Intervals
However, the point estimate is most likely not the exact value of the population parameter, but close to it. After calculating point estimates, we construct interval estimates, called confidence intervals or prediction intervals. This prediction interval comprises a range of values unlike the point estimate and is a better predictor of the observed sample value, y.
Adrenergic Receptors: ɑ Subtype
Adrenaline ≥ Noradrenaline >> Isoprenaline
α-adrenoceptors are further divided into α1 and α2-adrenoceptors.
α1-Adrenoceptors: These receptors are located postsynaptically on the effector organs and cause constriction of smooth muscle mediated by activation of phospholipase...
Adrenergic Receptors: β Subtype
Isoprenaline > Adrenaline > Noradrenaline
Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes.
β1-adrenoceptors: β1-adrenoceptors...
Diabetes Mellitus: Overview and Type I Subtype
Type 1 diabetes is an autoimmune disease in which the immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas. As a result, the body is unable to produce sufficient insulin, and individuals with...

