GetTheDiagnosis.org

Welcome, guest.
Login or Sign up to edit.

Add an entry

Search:
 

Tools

Add a finding for this diagnosis

Add prevalence for this diagnosis

Switch to calculator mode to see positive predictive value

Switch to sensitivity and specificity

Sort findings by Tag

Sort findings by Differential Diagnosis

Jump To

Good Positive and Negative Likelihood Ratios

Good Negative Likelihood Ratio

Good Positive Likelihood Ratio

Poorly Diagnostic Findings

Syndrome of Inappropriate ADH Secretion: Likelihood Ratios

Introduction: SIADH a major cause of hyponatremia and represents the condition when a euvolemic patient has increased ADH causing inappropriate retention of free water. The diagnosis is important as the treatment is fluid restriction rather than normal saline infusion.

For a review of the diagnosis, see http://cjasn.asnjournals.org/cgi/content/full/3/4/1175 (PMID 18434618)

[Edit Diagnosis] [Merge dx] [Add prevalence]

Tags: Endocrine Tag this Diagnosis.

Differential Diagnoses include: Hypovolemia

Prevalence

Population / CalculatorPrevalence Comments / Study / Link
Elderly patients with hyponatremia 31% 110 consecutive cases: 31% SIADH patients, 23% patients with hyponatremia due to diuretics, 18% potomania patients, 15% salt depleted patients, 5% salt depleted SIADH patients, 5% patients with a salt loosing syndrome and 3% patients with hyponatremia of unknown origin

Int Urol Nephrol. 2001;32(3):475-93. PMID: 11583374

More, Edit...

The likelihood ratios of findings for Syndrome of Inappropriate ADH Secretion are listed below. See the left navigation bar to change the display.

Good Positive and Negative Likelihood Ratios

Finding +LR-LR Comments, Study
Urine Sodium Edit 30.1

UNa > 30 indicates SIADH. However, UNa can be high in hypovolemic patients, especially those with low UOP.

Differential Diagnosis: Hypovolemia

Study: Clin J Am Soc Nephrol. 2008 Jul;3(4):1175-84. PMID: 18434618

Fractional Excretion of Sodium Edit inf0.3

FENa > 0.5%

Differential Diagnosis: Hypovolemia

Study: Clin J Am Soc Nephrol. 2008 Jul;3(4):1175-84. PMID: 18434618

Plasma Urea Edit 40.3

plasma Urea < 30 mg/dl suggests SIADH (because of dilution)

Differential Diagnosis: Hypovolemia

Study: Clin J Am Soc Nephrol. 2008 Jul;3(4):1175-84. PMID: 18434618

Good Negative Likelihood Ratio

Finding +LR-LR Comments, Study
Uric Acid Edit 1.80.5

uric acid < 4mg/dl suggests SIADH (because of dilution)

Differential Diagnosis: Hypovolemia

Study: Int Urol Nephrol. 2001;32(3):475-93. PMID: 11583374

Good Positive Likelihood Ratio

Finding +LR-LR Comments, Study
Fractional Excretion of Urea Edit 2.60.6

FEUrea > 50%

Differential Diagnosis: Hypovolemia

Study: Clin J Am Soc Nephrol. 2008 Jul;3(4):1175-84. PMID: 18434618

Poorly Diagnostic Findings

Finding +LR-LR Comments, Study
Clinical Assessment of Volume Status Edit 11

Study: Am J Med. 1987 Nov;83(5):905-8. PMID: 3674097