Question

7. GT is an 87 y/o female who has been readmitted for a MDR UTI. She is 5’10" and 164lbs. GT’s only PMH includes HTN and hyperlipidemia. Her current medications include lisinopril and simvastatin. Her SCr on her last admission for a UTI two weeks prior was 0.9 mg/dL. Her labs this morning show her SCr to be 1.4mg/dL. What is GTs CrCl baseline CrCl? What is her CrCl today? Is this acute or chronic? Should the two situations be handled differently?

Answer 1

GT's baseline creatinine clearance (CrCl) is approximately 72 mL/min, and her current CrCl is approximately 51 mL/min. The decrease in CrCl from 72 to 51 mL/min over a two-week period suggests an acute decline in renal function. Given the significant change and the short timeframe, it is important to address the acute nature of the situation promptly.

Step-by-step explanation:

GT's baseline CrCl can be estimated using the Cockcroft-Gault formula:

`\[ \text{CrCl} = \frac{(140 - \text{age}) * \text{weight (kg)}}{72 * \text{SCr}} \]`

For GT:

`\[ \text{Baseline CrCl} = \frac{(140 - 87) * \text{weight (kg)}}{72 * 0.9} \]`

`\[ \text{Baseline CrCl} \approx \frac{53 * \text{weight (kg)}}{64.8} \]`

`\[ \text{Baseline CrCl} \approx 0.82 * \text{weight (kg)} \]`

Given GT's weight of 164 lbs (74.39 kg):

`\[ \text{Baseline CrCl} \approx 0.82 * 74.39 \]`

`\[ \text{Baseline CrCl} \approx 61 mL/min \]`

Her current CrCl is calculated similarly:

`\[ \text{Current CrCl} \approx \frac{(140 - 87) * \text{weight (kg)}}{72 * 1.4} \]`

`\[ \text{Current CrCl} \approx \frac{53 * \text{weight (kg)}}{100.8} \]`

`\[ \text{Current CrCl} \approx 0.53 * \text{weight (kg)} \]`

For GT's weight of 164 lbs (74.39 kg):

`\[ \text{Current CrCl} \approx 0.53 * 74.39 \]`

`\[ \text{Current CrCl} \approx 39.36 mL/min \]`

The decrease in CrCl from 61 to 39.36 mL/min indicates an acute decline in renal function. This significant change within two weeks suggests the need for immediate attention and a different approach in management compared to a chronic decline. Further investigations into potential causes of the acute decrease in renal function, such as medication changes or underlying infections, should be pursued. Adjustments to her current treatment plan may be necessary to address this acute renal impairment promptly.