Case 2: Constrained T

Not a minute more than 3.5 hours!

67 year old African American male with history of diabetes, hypertension and advanced chronic kidney disease has been initiated on dialysis in the hospital. He has received 6 treatments so far and has done well without significant issues with hypotension or cramping. He will now be transitioning to your outpatient dialysis unit. The patient weighs 70kg and has a well functioning AV fistula. You have done your smart calculations (Case 1) and know that he needs to be dialyzed for 3.9 hours for a goal sp Kt/V of 1.4. However, the patient is adamant that he will not stay for more than 3.5 hours because that’s what his friend does. How would you calculate the initial dialysis prescription now?

STEP 1: Start with T since it it a non-negotiable for the patient
T = 3.5 hours or 210 min

STEP 2: Calculate your V
V = 60% of 70kg = 42L or 42,000 ml

STEP 3: Remember your goal spKt/V
spKt/V = 1.4

STEP 4: Do the math
1.4 x 42,000ml / 210min = 280ml/min

STEP 5: Assume that you would like to prescribe a Qb of 400ml/min and a Qd of 500ml/min

STEP 6: Select different KoA options to see what range your KoA should be to reach at goal spKt/V of 1.4