Sorbellini et al developed a nomogram for predicting the risk of renal insufficiency following a partial or total nephrectomy. This can help provide informed consent to the patient about one of the serious complications that can occur following surgery. The authors are from Memorial Sloan-Kettering Cancer Center and the Cleveland Clinic Foundation.
Endpoint: probability of renal insufficiency at 7 years after the surgical procedure
Parameters:
(1) age of the patient in years
(2) gender
(3) ASA score
(4) preoperative serum creatinine in mg/dL
(5) percent change in kidney volume as result of the surgery
percent change in renal volume =
= ((volume before surgery) - (volume after surgery)) / (volume before surgery) * 100%
|
Parameter |
Finding |
Points |
|
age of the patient in years |
< 10 |
0 |
|
|
10 - 100 |
(0.3083 * (age)) - 3.0833 |
|
|
> 100 |
27.75 |
|
gender |
female |
0 |
|
|
male |
6.2 |
|
ASA score |
I or II |
0 |
|
|
III |
4.75 |
|
|
IV or V |
5.2 |
|
percent change in volume |
|
(0.0925 * (percent)) + 9.25 |
|
preoperative creatinine |
0 to 1 mg/dL |
(61.9 * (creatinine)) |
|
|
1 to 2 mg/dL |
(15.1 * (creatinine)) + 46.8 |
|
|
2 to 9 mg/dL |
see below |
|
|
> 9 mg/dL |
100 |
where:
• The paper refers to ASA scores from 0 to 4. My experience has been with the scale from I to V.
• The range for percent change in renal volume will usually be from 0 to 100%. The nomogram includes points for negative percent change, which would entail hypertrophy of the remaining kidney, if any. Considering that a partial or total nephrectomy is done, this would involve significant hypertrophy.
• Using linear equations for serum creatinine from 0 to 1 and from 1 to 2 mg/dL may not be the most accurate way for point assignment but is the simplest.
points for serum creatinine from 2 to 9 mg/dL =
= (-0.03214 * ((creatinine)^2)) + (3.637 * (creatinine)) + 69.79
total score =
= SUM(points for all 5 parameters)
Interpretation:
• minimum score: 0 (practically 5, since the kidney is unlikely to be larger after surgery)
• maximum score: around 160
• The higher the score the greater the chances of renal insufficiency within 7 years.
|
Total Score |
Probability of Not Having Renal Insufficiency |
|
< 92.3 |
> 0.99 |
|
92.3 - 107.5 |
(-0.005921 * (points)) + 1.5365 |
|
107.5 - 116.3 |
(-0.001794 * ((points)^2)) + (0.3781 * (points)) - 19.02 |
|
116.3 - 123.9 |
(-0.001128 * ((points)^2)) + (0.2172 * (points)) - 9.30 |
|
123.9 - 132 |
(0.003461 * ((points)^2)) - (0.9215 * (points)) + 61.34 |
|
> 132 |
< 0.01 |
Specialty: Nephrology, Clinical Laboratory
ICD-10: ,
