Consult Rounds: Cisplatin induced AKI, can we predict?

Cisplatin is a well known nephrotoxic agent. But here is a scenario. You have a 51 y old man with no history of HTN, baseline serum creatinine of 1.1mg/dl, well nourished now diagnosed with laryngeal cancer. He is planned to get cisplatin. What is the risk of AKI post first dose of cisplatin for this individual?

Prediction models are helpful in such instances to guide the oncologists and nephrologists. Similar to the prediction of AKI and need for dialysis post contrast as done by Mehran et al, Motwani et al developed a prediction model for cisplatin based AKI.

The predictive model demonstrated reasonably good discrimination and calibration. The multivariate model was developed using a large cohort of patients and internally and externally validated. Its uses age, HTN, albumin and dose of cisplatin as the major coordinates.

Identification of high-risk individuals may facilitate appropriate preventative options such as more frequent laboratory monitoring, avoidance of concurrent use of other renal tubular toxins, and careful evaluation of dosing and administration of additional intravenous fluids. This study also suggests that baseline kidney function measured by creatinine may not be a good predictor of the risk of cisplatin induced AKI after the first course. 

I summarized the scoring the investigators designed and validated. 

Score Assigned	Age
0	<=60
1.5	61-70
2.5	71-90
	HTN
2	Yes
0	No

Score Assigned	Cisplatin Dose(mg)
0	<= 100
1	101-150
3	>=151
	Serum ALBUMIN(g/dl)
0	>3.5
2	1.3-3.5

So if score is 0-3 your risk of AKI is 3-8%, if score is 3.5-6, 15% and >6, risk is 28-39%

So in our case example, if the patient were to get 88mg of cisplatin and his albumin was 4.5g/dl, his risk scores for Cisplatin-AKI after the first course would be as follows: age < 60 years = 0; dose < 100 mg = 0; no hypertension = 0; and albumin > 3.5 g/dL = 0. Therefore, his total risk score would be 0 and his predicted probability of developing C-AKI would be 3%

Another example, A 69-year old man with a medical history of type 2 diabetes mellitus, hypertension, has new gastric cancer and is cisplatin-based adjuvant chemotherapy with a dose of 200 mg. His baseline creatinine is 1.0 mg/dL and her serum albumin is 2.8 g/dL. His risk scores for cisplatin AKI after the first course would be as follows: age 61 to 70 years = 1.5; hypertension = 2; dose > 150 mg = 3; albumin < 3.5 g/dL = 2. Therefore, his total risk score would be 8.5 and his predicted probability of developing AKI would be 28-39%.

A very helpful tool indeed for all of us to use.