CALCULATIONS

Adjusted Calcium (mg/dL)

Calculation

Total Calcium + 0.8 x (4.0-Albumin)

Included In

Adjusted Calcium Phosphorus Product

Comprehensive Metabolic Panel

Comprehensive Metabolic Panel w/Phosphorus

Note

Calculation provided only when Albumin is <4.0 g/dL

 

Adjusted Calcium Phosphorus Product (mg²/dL²)

Calculation

(Total Calcium (mg/dL) + 0.8 x (4.0-Albumin (g/dL)) x Phosphorus

Included In

Adjusted Calcium Phosphorus Product

Comprehensive Metabolic Panel w/Phosphorus

Note

Calculation provided only when Albumin is <4.0 g/dL

  

A/G Ratio

Calculation

Albumin/Globulin

Included In

Comprehensive Metabolic Panel

Comprehensive Metabolic Panel w/Phosphorus

 

Anion Gap (mEq/L)

Calculation

Sodium – (Chloride + CO2)

Included In

Basic Metabolic Panel

Comprehensive Metabolic Panel

Comprehensive Metabolic Panel w/Phosphorus

Electrolytes

Renal Function Panel

 

 

Calcium Phosphorus Product (mg2/dL2)

Calculation

Total Calcium x Phosphorus

Included In

Calcium Phosphorus Product

Adjusted Calcium Phosphorus Product

Comprehensive Metabolic Panel w/Phosphorus

 

 

GFR (mL/min/1.73 m²)

Calculation

175 x (Scr)– 1.154x (age)– 0.203x (0.742 if female) x (1.210 if African American)

Included In

GFR (CKD, Non Dialysis)

Note

IDMS-Traceable Modification of Diet in Renal Disease (MDRD)

 

 

Globulin (g/dL)

Calculation

Total Protein–Albumin

Included In

Comprehensive Metabolic Panel

Comprehensive Metabolic Panel w/Phosphorus

 

 

Hemoglobin x 3 (g/dL)

Calculation

Hemoglobin x 3

Included In

Complete Blood Count (CBC) & Differential

Complete Blood Count (CBC) & Differential w/Reticulocytes

Hemoglobin

Hemoglobin & Hematocrit (H&H)

Hemogram (Complete Blood Count w/o Differential)

 

 

Iron Status w/Iron & Transferrin

Total Iron Binding Capacity (TIBC)
(µg/dL)

Calculation

Transferrin x 1.4

 

 

% Transferrin Saturation

Calculation

(Iron/(Transferrin x 1.4)) x 100

 

 

Lipid Panel

Cholesterol/HDL Ratio

Calculation

Cholesterol/HDL

Included In

Lipid Panel (Coronary Risk Profile)

 

 

Low Density Lipoprotein (mg/dL)

Calculation

Cholesterol – (Very Low Density Lipoprotein + HDL)

Included In

Lipid Panel (Coronary Risk Profile)

 

 

Very Low Density Lipoprotein (mg/dL)

Calculation

Triglycerides/5

Included In

Lipid Panel (Coronary Risk Profile)

Note

Only provided if Triglycerides are <400 mg/dL

 

 

Prothrombin Time (Protime): INR

Calculation

(PT Ratio)ISI

PT Ratio = (Patient PT/Mean Normal PT)ISI

Mean Normal PT = Geometric Mean

ISI = International Sensitivity Index

Included In

Prothrombin Time (PT)

 

 

% Recirculation

Calculation

(Systemic BUN – Arterial BUN)/(Systemic BUN – Venous BUN) x 100

Included In

Recirculation Study

 

 

 

Hemodialysis Calculations

Kt/V Equilibrated (eqKt/V)

Calculation

(0.924 x lnKt/V) – ((0.395 x lnKt/V) / (Min / 60)) + 0.056

Included In

Kt/V Standard, URR

Kt/V Standard, Natural Log, URR

Note

Leypoldt Formula

For patient dialyzing 2 or 4-6 times per week

For Kt/V Standard calculation purposes only, not reported

 

 

Kt/V Jindal

Calculation

(0.04 x ((Pre BUN – Post BUN) / Pre BUN x 100) – 1.2)

Included In

Kt/V Jindal (Not K/DOQI Recommended)

Note

Jindal Formula

The HD Adequacy Work Group feels this formula should not be used to measure delivered dose of Hemodialysis. (K/DOQI
Clinical Practice Guidelines for Hemodialysis Adequacy: Update 2000, Guideline 2)

 

 

Kt/V Natural Log (lnKt/V)

Calculation

(-Ln((Post BUN/Pre BUN) – (0.008 x Treatment
Time in mins/60)) + ((4-(3.5 x (Post BUN/Pre BUN)) x (Pre WT-Post WT)/Post WT))

Included In

Kt/V Natural Log, URR

Kt/V Natural Log, URR, nPNA

Kt/V Standard, Natural Log, URR

Note

Daugirdas II Formula

The K/DOQI recommendations are:
Prescribed dose of hemodialysis: Kt/V of 1.3

Delivered dose of hemodialysis: Kt/V >1.2

 

 

Kt/V Standard (stdKt/V)

Calculation

(168 x (1-exp(-eqKt/V)) / (Min/60)) /
((1-exp(-eqKt/V)) / eqKt/V + (168/Number of Treatment/(Min/60)) -1)

Included In

Kt/V Standard, URR

Kt/V Standard, Natural Log, URR

Note

Leypoldt Formula

For patient dialyzing 2 or 4-6 times per week

 

 

nPNA, Hemodialysis

Calculation

Treatment #1

Beginning of week PNA (PCR) = Pre BUN /(36.3 +
5.48 x Kt/V Natural Log + 53.5/ Kt/V Natural Log) + 0.168

Treatment #2

Midweek PNA (PCR) = Pre BUN /(25.8 + 1.15 x Kt/V
Natural Log + 56.4/ Kt/V Natural Log) + 0.168

Treatment #3

End of week PNA (PCR) = Pre BUN /(16.3 + 4.3 x
Kt/V Natural Log + 56.6/ Kt/V Natural Log) + 0.168

Included In

Kt/V Natural Log, URR, nPNA

Note

nPNA calculation is only applicable to patients on thrice-weekly dialysis without significant residual function.  nPNA calculated from Kt/V
without formal kinetic modeling according to Depner T and              
Daugirdas J:JASN 1996:7:780-785.

 

 

Urea Reduction Ratio (%)

Calculation

(1 – (Post BUN/Pre BUN)) x 100

Included In

Kt/V Jindal (Not K/DOQI Recommended)

Kt/V Natural Log, URR

Kt/V Natural Log, URR, nPNA

Kt/V Standard, Natural Log, URR

Kt/V Standard, URR

Urea Reduction Ratio w/Pre and Post BUN

 

 

 

PD ADEQUACY CALCULATIONS

Weekly Total Kt/V

Calculation

Weekly Residual Kt/V + Weekly Dialysate Kt/V

 

 

Weekly Residual Kt/V

Calculation

((Urine Urea Nitrogen/BUN) x (Urine Volume (mL)/Urine Collection Time (min)) x 10.08) / VSA

Note

Calculated if urine sample provided

 

 

Weekly Dialysate Kt/V

Calculation

((Dialysate UreaNitrogen/BUN) x (24 hour Dialysate Drain Volume (mL)/1000) x 7) / VSA

 

 

Weekly Total Creatinine Clearance (Liters/week/1.73 m²)

Calculation

Weekly Residual GFR + Weekly Dialysate Creatinine Clearance

 

 

Weekly Residual GFR (Liters/week/1.73 m²)

Calculation

Arithmetic Mean of Weekly Urea Clearance and Weekly Creatinine Clearance

((Urine Urea Nitrogen/BUN) x (Urine Volume (mL)/Urine Collection Time (min) x 10.08) + (Urine Creatinine/Plasma Creatinine x Urine Volume (mL)/Urine Collection Time (min) x 10.08))/2 x 1.73/BSA

 

 

Weekly Dialysate Creatinine Clearance (Liters/week/1.73 m²)

Calculation

(Dialysate Corrected
Creatinine/Plasma Creatinine) x (24 hour Dialysate Drain Volume (mL)/1000) x 7 x 1.73/BSA

 

 

Corrected Creatinine, 24 Hour (mg/dL)

Calculation

Creatinine at 24 Hour Dwell – (Glucose at 24 Hour Dwell x 0.00010386)

 

 

nPNA, Peritoneal Dialysis (g/kg/day)

Calculation

(10.76 x ((0.69 x UNA) + 1.46)) / (VSA/0.58)

 

 

Protein Nitrogen Appearance (PNA) (g/day)

Calculation

10.76 x ((0.69x UNA) + 1.46)

 

 

UNA (g/day)

Calculation

(24 Hour Drain Volume (mL) x 24 Hour Urea Dialysate)/100000 + (Urine Volume (mL) x Urine Urea Nitrogen)/100000) x (1440/Total Urine Collection Time (min))

Note

For PNA calculation purposes only, not reported

 

 

Body Surface Area (BSA)

Calculation

Adult (≥16 years) uses DuBois and DuBois formula

BSA (m²) = 0.007184 x Wt^0.425 x Ht^ 0.725

Pediatric (< 16 years) uses Haycock formula

BSA (m²) = 0.024265 x Wt^0.5378 x Ht^0.3964

where weight (Wt) is in kilograms and height (Ht) is in centimeters

 

Volume (V) from Surface Area (Liters)

Calculation

Adult (≥16 years) uses Hume and Weyers formula 

Male: V= -14.012934 + 0.296785 x Wt + 0.194786 x Ht

Female: V = -35.270121 + 0.183809 x Wt + 0.344547 x Ht

Pediatric (<16 years) uses Friis-Hansen formula

V = 0.135 x Wt^0.666 x Ht^0.535

where weight (Wt) is in kilograms and height (Ht) is in centimeters

Included In

PD Adequacy

Residual Urea Clearance (KrU)

 

 

Peritoneal Equilibration Test (PET) Fast

Corrected Creatinine, 4 Hour (mg/dL)

Calculation

Creatinine at 4 Hour Dwell – (Glucose at 4 Hour Dwell x 0.00010386)

 

 

Corrected Creatinine D/P, 4 Hour

Calculation

Corrected Creatinine at 4 Hour Dwell/Plasma Creatinine at 2 Hour Dwell

 

Peritoneal Equilibration Test (PET) Standard

Corrected Creatinine, 0 Hour, 2 Hour, 4 Hour (mg/dL)

Calculation

Creatinine at 0 or 2 or 4 Hour Dwell – (Glucose at 0 or 2 or 4 Hour Dwell x 0.00010386)

 

 

Corrected Creatinine D/P, 0 Hour

Calculation

Corrected Creatinine at 0 Hour Dwell/Plasma Creatinine at 2 Hour Dwell

 

 

Corrected Creatinine D/P, 2 Hour

Calculation

Corrected Creatinine at 2 Hour Dwell/Plasma Creatinine at 2 Hour Dwell

 

 

Corrected Creatinine D/P, 4 Hour

Calculation

Corrected Creatinine at 4 Hour Dwell/Plasma Creatinine at 2 Hour Dwell

 

 

Glucose D/D0, 2 Hour

Calculation

Glucose at 2 Hour Dwell/Glucose at 0 Hour Dwell

 

 

Glucose D/D0, 4 Hour

Calculation

Glucose at 4 Hour Dwell/Glucose at 0 Hour Dwell

 

 

Urea D/P, 0 Hour

Calculation

Urea at 0 Hour Dwell/Urea at 2 Hour Dwell

 

 

Urea D/P, 2 Hour

Calculation

Urea at 2 Hour Dwell/Urea at 2 Hour Dwell

 

 

Urea D/P, 4 Hour

Calculation

Urea at 4 Hour Dwell/Urea at 2 Hour Dwell

 

 

Fluid, 24-Hour Dwell

Corrected Creatinine, 24 Hour (mg/dL)

Calculation

Creatinine at 24 Hour Dwell – (Glucose at 24 Hour Dwell x 0.00010386)

 

 

Fluid, Overnight Dwell

Corrected Creatinine, Overnight (mg/dL)

Calculation

Creatinine Overnight Dwell – (Glucose Overnight Dwell x 0.00010386)

 

 

Creatinine Clearance, Urine (Residual Renal Creatinine Clearance)

Calculation

(Urine Creatinine/Blood Creatinine) x (Urine Volume (mL)/Urine Collection Time (min)) x (1.73/BSA)

Included In

Urine Creatinine Clearance

 

 

Body Surface Area (BSA)

Calculation

Adult (≥16 years) uses
DuBois and DuBois formula

BSA (m²) = 0.007184 x Wt^0.425 x
Ht^0.725

Pediatric (< 16 years)
uses Haycock formula

BSA (m²) = 0.024265 x Wt^0.5378 x
Ht^0.3964

where weight (Wt) is in
kilograms and height (Ht) is in centimeters

 

 

Residual Urea Clearance, KrU – for Hemodialysis only

KrU (mL/min)

Calculation

(Urine Urea Nitrogen x Urine Volume (mL)) / (Blood BUN x 0.9 x Total Urine Collection Time (min))

 

 

Kt/V Residual

Calculation

(Urine Urea Nitrogen/Blood BUN) x (Urine Volume (mL)/ Urine Collection Time (min))  x (10.08/VSA)

 

 

Volume from Surface Area (Liters)

Calculation

Adult (≥16 years) uses
Hume and Weyers formula 

Male: V= -14.012934 + 0.296785 x
Wt + 0.194786 x Ht

Female: V = -35.270121 + 0.183809
x Wt + 0.344547 x Ht

Pediatric (<16 years)
uses Friis-Hansen formula

V = 0.135 x Wt^0.666 x Ht^0.535

where weight (Wt) is in kilograms and height (Ht) is in centimeters

Included In

PD Adequacy

Residual Urea Clearance (KrU)

 

Urine Creatinine, 24 Hour (mg/24 hour)

Calculation

(Urine Creatinine/100) x Total Urine Volume in mL

Included In

24 Hour Urine Creatinine

 

Urine Urea Nitrogen, 24 Hour (g/24 hour)

Calculation

(Urine Urea Nitrogen in mg/dL/100) x Total Urine Volume in mL) / 1000

Included In

24 Hour Urine Urea Nitrogen