Fractional Excretion of Sodium

CalcFENa.vb

Sub Main
	Console.WriteLine(CalcFENa(70, 150, 4000, 50))	
End Sub


' Fractional Excretion of Sodium (FENa), % = 100 × (SCr × UNa ) / (SNa × UCr)
' FENa is a measure of tubular resorption of Na.
'         Pre-Renal	Intrinsic	Post-Renal
' FENa    <1%>      1%	        >4%
Function CalcFENa (dblScreat As Double, dblSNa As Double, dblUcreat As Double, dblUNa As Double) As Double
	Dim dblFENa As Double = -1
	If dblScreat > 0 And dblSNa > 0 And dblUcreat > 0 And dblUNA > 0 Then
		dblFENa = 100 * (dblScreat * dblUNa) / (dblUcreat * dblSNa)
	End If
	
	Return dblFENa
End Function