1. Renal Pharmacy Group Beginners Lectures 2018
Introduction to the
renal patient pathway

2. Stages of CKD CKD stage Comment eGFR (ml/min/1.73 m2) 1
Kidney damage with normal or  GFR
90ml/min 2
Kidney damage with mild  GFR
60-89ml/min 3A
Kidney damage with Moderate  GFR
45-59ml/min 3B
30-44ml/min 4
Severe  GFR
15-29ml/min 5
Established renal failure
<15ml/min (or dialysis)

3. Acute Kidney Injury Network (AKIN) Staging
Stage
Serum creatinine (SCr) criteria
Urine Output criterai 1
Increase in SCr ≥ 26µmol/l within 48hrs Or
Increase ≥ 1.5 – 1.9 x reference SCr
< 0.5ml/kg/hr for more than 6 consecutive hours 2
Increase ≥ x reference SCr
< 0.5ml/kg/hr for more than 12 consecutive hours 3
Increase ≥ 3x reference SCr
Increase ≥ 354µmol/l
Commenced on renal replacement therapy (RRT) irrespective of stage
< 0.3ml/kg/hr for more 24 hours
Anuria for 12 hours

4. Cockcroft and Gault Equation
Provides calculated creatinine clearance, which is a surrogate marker of GFR
CrCl (ml/min) = F x (140-age) x wt (kg)
serum creatinine (mol/L)
F = 1.04 Female
= 1.23 Male
Overestimates in obese and underestimates in small patients – Use actual body weight if BMI<18.5, IBW if BMI or adjusted body weight if BMI>25
Not accurate in rapidly changing renal function
Most drug dosages based on this equation
Only validated in Caucasians

5. The 4 variable Modification of Diet in Renal Disease (MDRD) Equation
Provides estimated GRF (eGFR) normalised to BSA of 1.73m2
Best mathematical estimation – esp CKD stages 3, 4 & 5
eGFR = 175((serum creatinine (mol/l)/88.4)-1.154)
x (age (years)-0.203)
x if female and
x 1.21 if African American or African Caribbean
eGFR units = ml/min/1.73m2
Main advantage – no need for weight
Endorsed by UK CKD guidelines
Validated in Caucasians and African Americans
In patients with near normal renal function this equation can underestimate renal function

6. CKD-EPI calculation
NICE in 2014 suggested that the CKD-EPI equation should be used to estimate GFR using creatinine to confirm or rule out CKD if eGFR using MDRD is and no proteinuria on two occasions
There are two CKD-EPI equations, one using creatinine and one using cystatin-C
GFR = 141 × min(Scr/κ, 1)α × max(Scr/κ, 1) × 0.993Age × [if female] × [if black]
where: Scr is serum creatinine in µmol/L, κ is 61.9 for females and 79.6 for males, α is for females and for males, min indicates the minimum of Scr/κ or 1, and max indicates the maximum of Scr/κ or 1
The equation does not require weight because the results are reported normalized
to 1.73 m² body surface area, which is an accepted average adult surface area.

7. Comparison of estimates of GFR for two patients with the same serum creatinine
CrCl – Using Cockcroft and Gault (ml/min)
eGFR – Using MDRD eGFR calculator (ml/min/1.73m2)
Young, muscular, black male (20yr, 90kg)
Serum creatinine 110mol/l
120ml/min
>90ml/min/1.73m2 (normal renal function)
Thin, elderly female (75yr, 50kg)
Serum creatinine 110 mol/l
29ml/min
40ml/min/1.73m2 (stage 3 CKD)

8. Ways that patients may present to the renal team
AKI – no previous CKD, patient recovers or continues with degree of CKD
Acute on chronic – unknown CKD presents with AKI
GP finds an increase in creatinine and refers to nephrology clinic – could be AKI or CKD
Nephrology clinics follow up all patients with CKD

9. Low clearance clinic Patient monitored and symptoms controlled
Assessed for suitable
type of RRT
Slowing of time to
RRT

10. Types of RRT HD PD
Transplant
Conservative management

11. Peritoneal dialysis
Haemodialysis
Transplant
Pre dialysis clinic

12. Thankyou