Answer:
To calculate DD's CrCl (creatinine clearance), we can use the Cockcroft-Gault equation. This equation estimates the creatinine clearance based on age, weight, sex, and serum creatinine level.
The formula for the Cockcroft-Gault equation is:
CrCl = ((140 - age) x weight) / (serum creatinine x 72) (multiplied by 0.85 for females)
Let's plug in the given values:
Age: 66 years
Weight: 220 lbs
Serum creatinine: 1.4 mg/dL
First, we need to calculate the adjusted body weight for females because DD is a 66 y/o female. We can use the equation:
Adjusted body weight (ABW) = ideal body weight + 0.4 * (actual weight - ideal body weight)
The ideal body weight for females is calculated as:
Ideal body weight (IBW) = 45.5 kg + 2.3 kg * (height in inches - 60)
Given that DD is 5'5'' (65 inches), we can calculate her IBW:
IBW = 45.5 kg + 2.3 kg * (65 inches - 60)
IBW = 45.5 kg + 2.3 kg * 5 inches
IBW = 45.5 kg + 11.5 kg
IBW = 57 kg
Now, let's calculate the ABW:
ABW = 57 kg + 0.4 * (220 lbs - 57 kg)
ABW = 57 kg + 0.4 * 163 lbs
ABW = 57 kg + 65.2 lbs
ABW = 122.2 lbs
Next, we can calculate the CrCl using the Cockcroft-Gault equation:
CrCl = ((140 - age) x weight) / (serum creatinine x 72) (multiplied by 0.85 for females)
CrCl = ((140 - 66) x 122.2 lbs) / (1.4 mg/dL x 72) (multiplied by 0.85)
CrCl = (74 x 122.2 lbs) / (1.4 mg/dL x 72) (multiplied by 0.85)
CrCl = 9061.6 lbs / 100.8 mg/dL (multiplied by 0.85)
CrCl = 89.85 L/day
Therefore, DD's CrCl is approximately 89.85 L/day.