Every time you sit down for dialysis, your treatment generates a sheet full of numbers. Blood pressure readings, fluid removal targets, blood flow rates, treatment time — it's all there. Most patients never look at it. I want to change that, because understanding your treatment sheet is how you go from being a passenger to being a co-pilot in your own care.
The Pre-Treatment Numbers
Pre-Dialysis Weight
This is the most important pre-treatment number. You step on the scale, and the difference between this weight and your "dry weight" determines how much fluid the machine will remove during your session.
Dry weight is your ideal weight with no excess fluid. It's an estimate that your care team adjusts over time based on how you feel during and after treatment.
If you consistently feel lightheaded, crampy, or "washed out" after treatment, your dry weight might be set too low. If you have persistent shortness of breath or swelling between treatments, it might be too high. Speak up — dry weight is not a fixed number.
Pre-Dialysis Blood Pressure
Taken before the needles go in. High pre-dialysis BP (above 160/90) may indicate fluid overload or medication issues. Low BP (below 100/60) before you even start can predict a rough session ahead — let your nurse know.
Fluid Removal Goal (UF Goal)
UF stands for ultrafiltration — the process of removing excess fluid. Your UF goal is typically the difference between your current weight and your dry weight, expressed in liters or kilograms (1 liter = 1 kilogram of water).
Key rule: The maximum safe UF rate is generally 10-13 mL/kg/hour. Removing fluid faster than this dramatically increases your risk of crashes (sudden drops in blood pressure). If you gained 4 kg between sessions and your treatment is only 3.5 hours, the math doesn't work safely. This is why fluid control between sessions matters so much.
During Treatment: The Numbers That Move
Blood Flow Rate (Qb)
This is how fast blood moves through the dialysis circuit, measured in mL/min. Typical range: 300-500 mL/min.
- Higher Qb = more efficient dialysis (more blood cleaned per minute)
- Lower Qb = may be necessary for catheter patients or new fistulas
- If your Qb is consistently low, ask about your access flow — there may be a stenosis developing
Arterial and Venous Pressures
These monitor the pressures in the blood circuit:
- Arterial pressure (negative number): How hard the machine pulls blood from your access. Too negative means something is restricting flow — a clot, a needle position issue, or access stenosis.
- Venous pressure (positive number): How much resistance the blood encounters returning to your body. Increasing venous pressure over weeks can signal a narrowing in your access.
Transmembrane Pressure (TMP)
The pressure across the dialyzer membrane that drives fluid removal. High TMP means the dialyzer is working harder, possibly because it's getting clogged with clotted blood. If TMP is climbing during treatment, your nurse should be watching for clotting.
Blood Pressure During Treatment
Your BP is checked every 15-30 minutes during treatment. This is your crash warning system.
Watch for:
- Gradual decline: Normal as fluid is removed. A slow, steady drop is expected.
- Sudden drop: This is a dialysis crash (intradialytic hypotension). Symptoms: dizziness, nausea, yawning, tunnel vision, sweating. Tell your tech immediately.
- What they'll do: Stop or slow UF, put you in Trendelenburg position (feet up, head down), give you saline, possibly give you a snack.
Post-Treatment Numbers
Post-Dialysis Weight
Ideally, this should be close to your dry weight. If there's a significant discrepancy, either not enough fluid was removed (you gained more than expected between sessions) or your dry weight needs adjustment.
Treatment Time
This matters more than most patients realize. Your prescribed treatment time is calculated based on your body size, lab values, and clearance needs. Every minute counts. Leaving 15 minutes early regularly can reduce your Kt/V below adequate levels.
| Time Shortened | Approximate Kt/V Reduction |
|---|---|
| 10 minutes early | ~5% less clearance |
| 15 minutes early | ~8% less clearance |
| 30 minutes early | ~15% less clearance |
I understand wanting to leave early. Four hours is a long time. But those final minutes are when the deepest toxin clearing happens — the molecules that take longest to move from tissues into blood. Cutting treatment short is cutting into your long-term health.
Kt/V (Monthly)
Your dialysis report card. Calculated from pre- and post-BUN levels, treatment time, and fluid removal. Target: 1.2 or above for hemodialysis. This tells you whether your treatments are actually adequate. If it's consistently below 1.2, something needs to change: longer sessions, higher blood flow, larger dialyzer, or better access.
The Treatment Sheet Over Time
A single treatment sheet is a snapshot. A collection of them is a story. Here's what trends to watch for:
- Rising venous pressures over weeks: Possible access stenosis — mention it to your team before it becomes an emergency
- Increasing fluid gains between sessions: Diet compliance issue or changing residual kidney function
- BP crashes becoming more frequent: Dry weight may need adjustment, or your heart function may need evaluation
- Declining blood flow rates: Access maturation issue or developing stenosis
Your Rights as a Patient
You have the right to see every number on your treatment sheet. You have the right to ask questions about any value you don't understand. You have the right to request changes to your treatment parameters if you're consistently feeling unwell.
The machine has a screen. Your treatment has a record. Your care team has the knowledge. All you need is the curiosity to ask and the confidence to advocate for yourself.
Knowledge is not just power — in dialysis, knowledge is the difference between merely enduring treatment and actively directing it. The patient who understands their treatment sheet participates in their own healing.