Dialysis and matching simulation
This page has four parts, in the order you use them. Part 1 is what you need to know. Part 2 says what to do, in plain English. Part 3 shows the work done once on a case that is not yours. Part 4 is your own work and where to turn it in.
Open your materials, follow the steps, then turn in your work.
Simulate dialysis and HLA crossmatching to model how patients are kept alive and matched.
Optional: listen or watch a unit review▸
Part 1 of 4 · Background and definitions▸
💡 Big idea: Organ-replacement decisions integrate organ function, compatibility, urgency, expected benefit, risks, and organ-specific allocation rules rather than relying on one laboratory value or matching feature.
- • Hemodialysis passes blood across a semipermeable membrane to remove waste by diffusion.
- • antigens on cell surfaces are the primary targets of the recipient's immune system after transplant.
- • A positive (antibodies react with donor cells) predicts high risk and usually disqualifies the donor.
A defensible biomedical decision separates scientific evidence from value judgments, identifies who may benefit or be burdened, and states the uncertainty and tradeoffs that remain.
Organ-replacement decisions integrate organ function, compatibility, urgency, expected benefit, risks, and organ-specific allocation rules rather than relying on one laboratory value or matching feature.
Driving question: Simulate and crossmatching to model how patients are kept alive and matched.
What you already know: A defensible biomedical decision separates scientific evidence from value judgments, identifies who may benefit or be burdened, and states the uncertainty and tradeoffs that remain.
New idea: Organ-replacement decisions integrate organ function, compatibility, urgency, expected benefit, risks, and organ-specific allocation rules rather than relying on one laboratory value or matching feature.
Visual or model: No figure is attached to this lesson. The readings, the worked example and E1 to E3 carry the evidence.
- Observe or measure the relevant feature in today's lesson.
- Organize the observation with a stable evidence ID.
- Apply this rule: Use science to estimate consequences, then state the value judgment and tradeoff that determine the decision.
- Choose the option the evidence supports and state the limit of the conclusion.
Real biomedical example: Today the medical interventions team uses and matching simulation to make a bounded evidence decision. A classroom simulation omits many clinical and allocation variables and cannot rank or recommend care for real patients.
What the evidence supports: E1 to E3 support the daily take-home when the response meets the stated success criteria.
What it cannot prove: The package does not support claims beyond this lesson's or any real patient diagnosis.
- • : The kidney's microscopic filtering unit that cleans the blood, reabsorbs needed substances, and forms urine.
- • : A process that filters waste and excess fluid from blood across a semipermeable membrane, used clinically when the kidneys cannot do this job.
- • : Human antigens, proteins on cell surfaces that mark cells as self, helping the immune system spot foreign cells and guiding transplant matching.
- • : A lab test that checks whether a recipient's immune system will attack a donated organ by mixing recipient serum with donor cells.
- • : The immune system's attack on a transplanted organ or that it recognizes as foreign rather than part of the body.
- • : A reduced ability of the immune system to fight infection, caused by disease, medication, or treatment such as after an organ transplant.
Use it now: Choose one decision option. Cite E1 and E3, then explain how the rule connects the evidence to your choice. This is thinking practice for the one turn-in named under Turn in, not a second submission.
Go further, optional: The source links below are optional enrichment. Every fact required for today's local evidence decision appears in this lesson package.
Health Resources and Services Administration is the source this lesson's claim is checked against: How Organ Allocation Works
Limit: A classroom simulation omits many clinical and allocation variables and cannot rank or recommend care for real patients.
Use science to estimate consequences, then state the value judgment and tradeoff that determine the decision.
Limit: A review-board model organizes reasoning but does not make one ethical principle automatically outweigh every other principle.
You can model how lowers blood waste.
Limit: E3 defines the classroom product or success criterion. It is not independent scientific evidence and cannot justify a clinical or causal claim.
Today's decision · Simulated classroom evidence scenario
Your role: medical interventions team member
Decision: Your team must decide what the evidence from today's lesson supports before submitting the labeled and result claim named on today's page.
- • Ask whether results like ours actually predicted in real transplants, because practice data never checks its own prediction.
- • Judge the simulated match using function, compatibility, urgency, and risk together instead of leaning on one result.
- • Trust the simulation's clean result, since a well run model gives an answer good enough to rank real patients.
Response: State one choice, cite at least two evidence IDs, explain the rule that connects them, and add one limitation. Use it inside the one turn-in named under Turn in; it is not a separate submission.
Claim ceiling: Today's evidence supports a classroom claim about today's lesson. It cannot prove causation, diagnose a real patient, or justify action outside this room.
Reason for review: Your team must decide what the evidence from today's lesson supports before submitting the labeled and result claim named on today's page.
Context: Today the medical interventions team uses and matching simulation to make a bounded evidence decision. A classroom simulation omits many clinical and allocation variables and cannot rank or recommend care for real patients.
- • T1: Define and , then open the practice dialysis and matching data on this page.
- • T2: Read the practice readings and record how the waste level changes across the session.
- • T3: For each donor, record the match count and read the as positive or negative.
- • T4: Flag any that predicts and explain why.
- • T5: Record your and matching results in the simulation .
- • T6: Submit your completed simulation results.
- • E1: Health Resources and Services Administration is the source this lesson's claim is checked against: How Organ Allocation Works
- • E2: Use science to estimate consequences, then state the value judgment and tradeoff that determine the decision.
- • E3: You can model how lowers blood waste.
Measurements: Use only the measurements, units, graph, or counts supplied in today's task. No additional patient measurement is implied.
Uncertainty: This is a composite classroom scenario. Missing history, measurements, or confirmation tests remain unknown and limit the conclusion.
Rate or percent = part / comparison total x 100%. Percent change = (new - comparison) / comparison x 100%.
If 18 of 60 records meet a condition, the frequency is 18 / 60 x 100% = 30%.
Name the comparison total. A percent describes the supplied group and does not automatically predict an individual's outcome.
Use the counts in the practice data on this page to calculate one rate, risk, frequency, or percent change. Show the denominator and interpretation.
Students often think a polished answer about and matching simulation is trustworthy even when its evidence source, comparison, or limitation is missing. The trap: Presentation quality cannot raise the evidence level. A classroom simulation omits many clinical and allocation variables and cannot rank or recommend care for real patients.
- CER:
- Claim, Evidence, Reasoning: make a claim, back it with evidence, explain your reasoning.
- SOP:
- Standard Operating Procedure, the exact steps to follow (especially in a lab).
- Tracker:
- Your PLTW progress log where you record completed evidence.
- myPLTW:
- The PLTW course site where you do the online activities. Find it in Clever with your Microsoft sign-in, right next to Schoology.
Tap the speaker to hear a term. Add two of these to your notebook glossary with a definition and an example in your own words.
Pick just 2 or 3 words from today and make them yours: write what each one means in your own words, name the context clue or evidence that helped, then give one example from what you actually did in Dialysis and matching simulation. Try your own words first; the glossary is there if you get stuck. This is voluntary and counts as extra credit, so keep it short.
Saved on this device. Show Mr. Mendoza or add these to your notebook glossary to claim the extra credit.
Part 2 of 4 · Directions in plain English▸
2.1 Open your materials
Use the materials named in the first step below. Open lesson resources.
Practice dialysis and matching data (made up for practice, not real patients)
Practice recipient K-1: blood urea nitrogen (BUN) during one 4-hour hemodialysis session
| Time into the session | Blood urea nitrogen, BUN (mg/dL) |
|---|---|
| 0 min | 96 |
| 60 min | 71 |
| 120 min | 52 |
| 180 min | 39 |
| 240 min | 30 |
Three possible kidney donors for K-1
| Practice donor | HLA match count (out of 6) | Crossmatch result |
|---|---|---|
| D-1 | 3 of 6 | Negative |
| D-2 | 6 of 6 | Positive |
| D-3 | 4 of 6 | Negative |
- The HLA match count compares HLA types (HLA-A, -B and -DR, two each). The crossmatch mixes K-1's serum with the donor's cells and is read positive or negative; it is not a score.
2.2 Start the work
Define dialysis and crossmatch, then open the practice dialysis and matching data on this page.
Show all 6 required steps
- Define dialysis and crossmatch, then open the practice dialysis and matching data on this page.
- Read the practice dialysis readings and record how the waste level changes across the session.
- For each donor, record the HLA match count and read the crossmatch as positive or negative.
- Flag any crossmatch that predicts rejection and explain why.
- Record your dialysis and matching results in the simulation data table.
- Submit your completed simulation results.
Lost your place? Reopen today's Dialysis and matching simulation record. Find the last completed evidence ID, check it against the claim ceiling, and continue with the first unfinished step rather than restarting the whole task.
- 0-8Define and ; open the practice data on this page
- 8-30: record the practice waste level at each time point
- 30-52Matching: record each donor's match count and read each positive or negative
- 52-62Flag incompatible crossmatches; write explanation
- 62-72Complete simulation
- 72-80Submit results in Schoology; async post if remote
- • keeps the patient alive; matching decides whether a transplant will be rejected.
- • Today you model both with the practice data on this page, so you can see the data behind clinical decisions.
- • The practice data is made up; read it the way you would read real lab data.
- • Simulation data recording is a Lab SOPs skill directly tested on the WebXam.
PLTW connection and today's work
Open Activity 4.2.1 Medical Detectives (kidney failure and dialysis) and Activity 4.3.2 Finding a Match (HLA matching) in myPLTW, then complete the dialysis and matching simulation with the practice data on this page.
Today's stopping point: The allocation debate is done; dialysis and HLA simulation data table due today.
PLTW activity titles identify the course connection. If your account will not open, use the posted materials for today and tell Mr. Mendoza. Do not mark an online activity complete unless you completed it.
Course connection
- Activity 4.2.1 Medical Detectives
- Activity 4.3.2 Finding a Match
Use the turn-in directions in Part 4 of this page. Do not create a second submission unless your teacher asks for one.
Show another explanation or a smaller first step
Need help? Choose a starting point
Finish the assigned lab safely before starting extra practice.
Part 3 of 4 · Worked example▸
This is a parallel case, not your own. Read it for the order of the work, then do your own in Part 4.
Parallel practice case, not today's data (recipient Q-9, made-up numbers).
Dialysis waste-level time series (blood urea nitrogen, BUN):
- Start (0 min): 84 mg/dL
- 60 min: 63 mg/dL
- 120 min: 47 mg/dL
- 180 min: 36 mg/dL
- 240 min: 28 mg/dL
Reading: BUN fell by two thirds over four hours, fastest at the start when the gap between blood and dialysate was largest. The machine is doing the filtering the failed nephrons cannot, but only while it runs.
Matching results for Q-9:
- Donor W: HLA match count 2 of 6; crossmatch negative.
- Donor X: HLA match count 5 of 6; crossmatch positive.
- Donor Y: HLA match count 4 of 6; crossmatch negative.
The match count and the crossmatch are two different tests. The count compares HLA types; the crossmatch mixes Q-9's serum with the donor's cells and reads positive or negative.
Rejection-risk flag:
- Donor X flagged: a positive crossmatch means Q-9 already has antibodies against Donor X's cells, which predicts rapid rejection, even with 5 of 6 HLA matches.
(Tip: read every crossmatch as positive or negative before you look at the match counts.)
This model shows the level of evidence and organization needed to complete: Models the simulation data table on a parallel practice recipient: waste levels across a dialysis session, each donor's HLA match count and crossmatch result read positive or negative, and the rejection flags with a reason.
- Name the variables and include units.
- Enter observations without changing the raw values.
- Check labels, calculations, and patterns before interpreting the data.
Keep the structure. Replace the question, facts, measurements, and evidence. Then recheck units, vocabulary, and whether the conclusion goes beyond the evidence.
Also due today: turns in the completed simulation table in Schoology under today's data-table assignment.
A review board sorts scientific evidence, stakeholder needs, possible benefits, possible burdens, and uncertainty before choosing a policy.
- Which statements are scientific evidence?
- Which statements express a value or priority?
- Who receives the benefit and who carries the burden?
Use science to estimate consequences, then state the value judgment and tradeoff that determine the decision.
A review-board model organizes reasoning but does not make one ethical principle automatically outweigh every other principle.
- • Evidence cards map to source-backed findings.
- • Stakeholder cards map to affected people and priorities.
- • The recommendation maps to an explicit tradeoff with a named uncertainty.
Part 4 of 4 · Your work▸
Check your work before submitting
- You'll be able to model how dialysis lowers blood waste.
- You'll be able to read an HLA crossmatch as positive or negative and predict rejection risk.
Before lab work: read the safety rules
- No biological materials or chemicals are used; the data is practice data.
- The donors and the recipient are made up; do not add any real person's health information to your table.
4.1 Turn in your work
DueCheck the Schoology assignment for this day- Hand in
- Simulation data table: dialysis waste-level time series, each donor-recipient pair's HLA match count and crossmatch result (positive or negative), and rejection-risk flags with explanations.
How to submit and name your file
Submit as one PDF in Schoology.
In Schoology, open your course and the assignment for this lesson. Attach your file, select Submit, and check that it appears in the submission.
PDF upload helpYou get two school days for every day you were absent, so this deadline moves with you.
Today's lesson is in Schoology
Each school day has one lesson page in Schoology that holds everything for the day: the goal, the story so far, every table and data value, the numbered steps, and what to turn in. Open it first and work from it. The other rows for this day, if any, are the score line for a paper quiz or test and the John Carroll debate item; they do not add work. Check Schoology for each deadline.
- Today's Lesson · Tue 12/15 · Wk17 · Clinical trials: phases, designs, and six ads, then the rules that protect research subjects(today's lesson page: the goal, the data, the steps, and what to turn in are all on it)
Link will not open? Open Schoology, choose your course and section, and find the title shown above.
- CompleteEvery required part of the artifact is present, nothing left blank.
- AccurateThe science and the data are correct and match the evidence.
- Scientific reasoningYou explain your claim with evidence and reasoning (CER), not just an answer.
- Professional communicationClear, organized, labeled, and written the way a clinician or scientist would.
- SubmittedGo to Schoology to turn this in. Submit one PDF. Schoology attaches your name to your upload; on the page itself, write your period and code. Name the file: FirstName LastName - Assignment Title - YYYY-MM-DD.pdf. If you cannot get in, see Mr. Mendoza. Do not skip the work.
- Error analysis and method · counts doubleName a specific limit of the method and how it moved your result, and compare what you predicted to what happened. "Human error" does not count; say what about the procedure or instrument caused it.
How this lesson connects
Keep using what you learned last class: A defensible biomedical decision separates scientific evidence from value judgments, identifies who may benefit or be burdened, and states the uncertainty and tradeoffs that remain. Today: Organ-replacement decisions integrate organ function, compatibility, urgency, expected benefit, risks, and organ-specific allocation rules rather than relying on one laboratory value or matching feature.
Practice: try a question, then check your answer▸
Claim ceiling for this check: Today's evidence supports a classroom claim about today's lesson. It cannot prove causation, diagnose a real patient, or justify action outside this room.
A student treats one classroom result about dialysis and matching simulation as proof. What must the student add before the conclusion is defensible?
Write an answer and pick a confidence to unlock the key.
Fast retrieval with instant answers, not the commit-then-reveal check above. Try each from memory first: write what you remember about the earlier units, then check yourself here.
Missed class or ready for more?▸
Run this before you touch the bench. It is built from the real lab procedure, so the decisions you make here are the ones you will make with the equipment in your hands.
I can name the procedure's purpose and the evidence I will record. I can state today's specific hazards and the control for each. If this deck does not name them, I ask Mr. Mendoza before I touch anything. My data table is ready before materials are handled.
Finish the checklist before you handle any material.
- • No biological materials or chemicals are used; the data is practice data.
- • The donors and the recipient are made up; do not add any real person's health information to your table.
- 1Before materials are handled, identify the purpose, variables or comparison, controls, measurement units, and stop-work condition.
- 2Define dialysis and crossmatch, then open the practice dialysis and matching data on this page.
- 3Read the practice dialysis readings and record how the waste level changes across the session.
- 4For each donor, record the HLA match count and read the crossmatch as positive or negative.
- 5Flag any crossmatch that predicts rejection and explain why.
- 6Record your dialysis and matching results in the simulation data table.
- 7Submit your completed simulation results.
- 8Record each result in the prepared table before interpreting it. Mark missing, repeated, or invalid results truthfully.
- 9Complete the named cleanup and waste route, remove PPE safely, wash hands when required, and confirm the station is ready for the next group.
| Which trial or sample this row is | What you changed on purpose | What you measured, with units | What you saw, before you explain it | Anything that could make this reading wrong |
|---|---|---|---|---|
Before the procedure, predict the result and cite the rule behind the prediction.
After the procedure, compare the result with the prediction and name one limitation or source of uncertainty.
What today's skills lead to. These are real health-science careers this course builds toward. Tap one to see, on the US Department of Labor's O*NET site, what the job actually involves, what it pays, and how fast it is growing.
At home: use the practice and matching data on this page to complete the simulation (waste levels across the session, each donor's match count and result, and the flags), then submit it.
MedlinePlus: DialysisSubmit as one PDF in Schoology.
Class still runs. Complete today's work as this page describes (it is self-guided). Need the concept taught without a teacher? Use this authoritative explainer:
MedlinePlus: DialysisThe optional extra-credit track is open. Complete reserved-unit work from home, including virtual labs, for extra credit. Each item shows its correct submission route.
Open the extra-credit trackSources: slides, readings, and resources▸
The deck carries the prior idea forward, lets you inspect an analogy, maps the rule to biology, and ends with the same evidence decision and exit ticket used on this page.
Classroom documents for this lesson are posted in Schoology. Open Clever, then Schoology, and find each one by the name shown on its card.
Use this for optional reserve or extra-credit work after the required class lesson is complete.
Use this for optional reserve or extra-credit work after the required class lesson is complete.
Use this for optional reserve or extra-credit work after the required class lesson is complete.
Sign in to Clever with your district Microsoft account to open Schoology or myPLTW. Follow today's posted steps. If myPLTW will not open, use the posted alternative and tell Mr. Mendoza. Turn in your completed work through the Schoology assignment.
This week
My Progress dashboard