clinPK (version 0.13.0)

calc_kgfr: Calculate kinetic GFR

Description

Calculate the kinetic GFR based on a patients first two serum creatinine measurements. Kinetic GFR may be more predictive of future AKI for patients whose serum creatinine is changing quickly. Briefly, an increase in SCr over the course of a day indicates an effective GFR lower than the most recent SCr measurement may indicate if steadystate is assumed, while a decrease in SCr over a short time indicates a higher effective GFR than the most recent SCr would indicate. There are several ways of approximating maximum theoretical creatinine accumulation rate; here the method used by Pianta et al., (PLoS ONE, 2015) has been implemented.

Usage

calc_kgfr(
  scr1 = NULL,
  scr2 = NULL,
  scr_unit = "mg/dl",
  time_delay = NULL,
  weight = NULL,
  vd = NULL,
  egfr = NULL,
  egfr_method = NULL,
  sex = NULL,
  age = NULL,
  height = NULL,
  ...
)

Value

kGFR, in ml/min

Arguments

scr1

baseline scr

scr2

second scr measurement

scr_unit

scr unit, defaults to mg/dl

time_delay

time between scr1 and scr2 in hours

weight

patient weight in kg

vd

volume of distribution in L, defaults to 0.6 * weight

egfr

eGFR in ml/min at the time of scr1, or leave blank to call calc_egfr

egfr_method

string, only necessary if egfr is not specified.

sex

string (male or female), only necessary if egfr is not specified.

age

age in years, only necessary if egfr is not specified.

height

in m, necessary only for some egfr calculation methods.

...

further arguments (optional) to be passed to calc_egfr.

References

Pianta et al., PLoS ONE (2015)

Examples

calc_kgfr(weight = 100, scr1 = 150, scr2 = 200, scr_unit = 'umol/l',
         time_delay = 24, egfr = 30)
calc_kgfr(weight = 70, scr1 = 350, scr2 = 300, scr_unit = 'umol/l',
          time_delay = 24, egfr_method = 'mdrd', age = 70, sex = 'male')