Active Patient
Patient A.Session 04
Command Center
Interactive PFT Workstation Coach
Study Type
Full Pulmonary Function TestSpirometry, volumes, diffusion, advanced review
Current Status
Interpretation in progressQuality, pattern, and report sequence active
Primary Action
Confirm quality firstThen anchor the read at the ratio
Session and Report Settings
Contraindications and Pre-Test Preparation
Use this as a pre-test safety screen alongside local policy, supervising clinician review, and current ERS/ATS technical standards. The emphasis here is on the practical findings most likely to delay, adapt, or stop testing on the day.
Spirometry
Screen first- Recent pneumothorax, haemoptysis of unknown origin, or unstable cardiovascular status.
- Recent thoracic, abdominal, eye, or neurosurgical procedure, or known aneurysm risk.
- Acute nausea, vomiting, pain, or inability to perform acceptable forced manoeuvres.
Essential prep
- Loose clothing, no heavy meal immediately before testing, confirm bronchodilator withholding plan if required by the question.
- Record recent symptoms, recent procedures, and medications that may alter lung function.
DLCO and Lung Volumes
Screen first- Uses the same manoeuvre-related cautions as spirometry if the patient cannot inhale, hold, and exhale reliably.
- For DLCO, note supplemental oxygen use and whether the patient can safely come off oxygen long enough for testing if clinically appropriate.
Essential prep
- No smoking before testing and avoid vigorous exercise beforehand because both can alter gas-transfer measurements.
- Avoid large meals or excess fluid beforehand; measure height and weight carefully for reference calculations.
FeNO
Screen first- Low-risk test overall, but interpretation is less useful when technique is poor or recent exposures are not controlled.
- Record active smoking, recent respiratory infection, allergen exposure, and current corticosteroid use.
Essential prep
- Avoid eating, drinking, strenuous exercise, and smoking immediately before the test if possible.
- Keep timing and technique consistent for serial monitoring.
Bronchial Challenge
Screen first- Baseline airflow limitation matters: methacholine is generally avoided when pre-bronchodilator FEV1 is below 60% predicted or 1.5 L in adults.
- Exercise or EVH challenge is generally avoided when baseline FEV1 is below 75% predicted.
- Recent MI or stroke, uncontrolled hypertension, aneurysm risk, recent eye surgery, pregnancy, or inability to perform repeatable spirometry should trigger review before proceeding.
Essential prep
- Complete a pre-test screening questionnaire and confirm medication withholding times based on the chosen challenge.
- Recent viral infection, allergen exposure, or irritant exposure can increase responsiveness and distort interpretation.
Respiratory Muscle Testing
Screen first- Use caution when recent facial, oral, thoracic, abdominal, or eye procedures make maximal pressure efforts unsafe or unreliable.
- Do not over-interpret when mouth seal, bulbar weakness, cognition, or cooperation makes the manoeuvre technically weak.
Essential prep
- Explain the manoeuvre clearly, optimise mouth seal and posture, and use nose clips where appropriate.
- Take enough attempts for reliable maximal efforts, but stop if distress or technique failure persists.
CPET
Screen first- Absolute concerns include uncontrolled cardiovascular disease, unstable arrhythmia, acute myocarditis or pericarditis, pulmonary embolism, pulmonary oedema, uncontrolled asthma, severe pulmonary hypertension, acute systemic illness, or complicated pregnancy.
- Relative concerns include resting SpO2 at or below 85% on room air, orthopaedic limitation, or inability to cooperate safely.
Essential prep
- Avoid strenuous exercise for 24 hours, avoid caffeine on the day, avoid smoking beforehand, and avoid eating for at least 2 hours before testing.
- Check vitals, medication list, and in diabetes consider pre-test glucose.
Medication Withholding Guide
Exact withholding intervals depend on the test question, local lab policy, and the agent used. Use this section as an operator check for what should be confirmed and documented before testing rather than as a substitute for protocol-specific timing.
Spirometry / Bronchodilator Testing
Check before baseline or reversibility testing- Short-acting bronchodilators: confirm the last dose and whether baseline testing is intended before rescue medication.
- Long-acting bronchodilators and long-acting muscarinic agents: document the current regimen if bronchodilator responsiveness or true baseline function is being assessed.
- Inhaled corticosteroids are usually recorded for context rather than withheld for routine spirometry.
Methacholine / Mannitol / EVH
Protocol-sensitive withholding matters most here- Confirm the challenge protocol being used before testing, because withholding windows differ across short-acting and long-acting bronchodilators.
- Check antihistamines, leukotriene modifiers, caffeine exposure, smoking, vigorous exercise, and recent respiratory infection because each may alter airway responsiveness.
- Document recent rescue inhaler use carefully if symptoms were active in the hours before testing.
FeNO
Interpret with treatment context visible- Record inhaled corticosteroid use because it can lower FeNO and change interpretation even when not withheld.
- Record biologics, leukotriene-directed therapy, active smoking, recent nitrate-rich meals, and recent exercise when serial comparison is important.
- Keep the pre-test routine consistent when FeNO is being trended over time.
DLCO / Lung Volumes
Medication issues are usually contextual- These tests usually do not require the same bronchodilator withholding strategy as challenge studies unless the local protocol says otherwise.
- Document smoking, supplemental oxygen use, recent exertion, and any medication change that may explain gas transfer or ventilatory change.
CPET
Make the intention explicit- Beta-blockers, rate-limiting agents, bronchodilators, insulin, and supplemental oxygen should be reviewed in advance because they may substantially change physiological interpretation.
- Decide before testing whether the goal is real-world performance on usual therapy or assessment under a modified medication plan.
- Document caffeine, nicotine, recent exercise, and recent medication changes on the day of testing.
Operator Reminder
What to record every time- Last inhaler dose, name of the inhaler, and whether the patient followed prep instructions.
- Any reason the medication could not be withheld safely.
- Whether the test should be interpreted as on-treatment physiology rather than untreated baseline physiology.
Quality Criteria Quick Check
Use this as a fast operator screen before interpretation starts. The purpose is to decide whether the session is reportable, usable with caution, or should be repeated before sign-off.
Spirometry
Acceptability and repeatability- Check for a rapid start: back extrapolated volume should be within 5% of FVC or 0.100 L, whichever is greater.
- Look for no cough in the first second, no glottic closure, no leak, and no early termination.
- Adult repeatability target is usually within 0.150 L for both FEV1 and FVC between the best acceptable blows.
- Eight forced manoeuvres is usually a practical upper limit in adults; stop sooner if fatigue or falling values make the session unsafe.
DLCO
Check manoeuvre quality before averaging- Inspired volume should be at least 90% of the largest VC in the session, or at minimum acceptable by standard with matching VA.
- At least 85% of test gas should be inhaled in under 4 seconds.
- Breath-hold should be stable for 10 plus or minus 2 seconds, without Valsalva, Mueller manoeuvre, or leak.
- Two acceptable values should be within 2 mL per minute per mmHg of each other before averaging.
Lung Volumes
Technical confidence matters- Check for stable end-expiratory level, good seal, and no obvious leak or panting error.
- Linked spirometry manoeuvres should be technically sound, because TLC and RV interpretation depends on the linked vital capacity.
- If body box, dilution, or washout values look discordant, confirm technique before over-interpreting physiology.
FeNO
Technique consistency is the quality check- Keep exhalation flow steady at the target device flow and avoid leak around the mouthpiece.
- Watch for poor inspiration, interrupted exhalation, or nasal contamination if the trace looks erratic.
- Serial interpretation is only reliable when timing, prep, and technique are consistent between visits.
CPET
Was it a real peak test?- RER above about 1.05 supports a maximal effort in many adults, but effort judgment should stay multi-factorial.
- Also consider symptom limitation, heart-rate response, workload, and whether the operator believed the patient reached limit of tolerance.
- Stop interpretation and reframe the report if the study ended early for non-physiological reasons or unsafe events.
Quick Reporting Rule
Decide before reading physiology- Acceptable: proceed with standard interpretation.
- Usable with caution: report the limitation clearly and lower confidence in the affected measures.
- Unacceptable: repeat or defer the test rather than forcing a definitive physiological label.
Reference Equations and Lab Setup
Use this section to make the workstation feel site-specific. These settings define how predicted values, LLN, bronchodilator policy, challenge interpretation, and report wording are applied across the lab.
Reference Defaults
Current workstation baseline- Spirometry: GLI 2012 equations.
- DLCO: GLI 2017 transfer factor equations.
- Lung volumes: GLI 2021 lung volume equations where appropriate and supported.
- Interpretive thresholding: LLN / ULN and z-scores rather than fixed ratio shortcuts.
Site Configuration
Decide once for the lab- Which reference set is standard for spirometry, lung volumes, and DLCO.
- How to handle patients outside the validated age range, including the degree of uncertainty added to the report.
- How ancestry or race-neutral reporting should be handled locally if required by policy.
Bronchodilator Policy
Make the reporting rule explicit- Decide whether routine reporting emphasizes change relative to predicted values, absolute change, or both.
- Define how the lab documents incomplete withholding, rescue medication use, or clinically necessary deviations from protocol.
- Keep the same wording standard across all operators.
Challenge Pathway
Protocol choice changes interpretation- Confirm whether methacholine, mannitol, exercise, or EVH is the preferred challenge for the site and indication.
- Define the positivity threshold and required withholding sheet for each protocol.
- Record whether the lab reports delivered dose, provoking dose, fall threshold, or local abbreviated wording.
Reporting Defaults
Choose a consistent product style- Short, standard, or teaching output can be selected as the default report style.
- Decide how much advanced testing detail appears in routine reports versus consultant-facing reports.
- Define whether serial change language is automatic or only added when prior studies are entered.
Implementation Note
Best next partner step- Turn these defaults into a site profile for each partner lab.
- Version-control any future change in reference equations or interpretive policy.
- Keep a visible note when a result is interpreted outside the core validated range or without the normal configuration assumptions.
Operator Grading Assistant
The coach shows the software-suggested grade and explains whether your chosen grade is aligned, stricter, or too optimistic for the entered maneuver count and repeatability.
Spirometry Inputs
Auto Curve Model
The flow-volume and volume-time previews now infer shape from the entered FEV1, FVC, ratio, and bronchodilator values instead of requiring manual curve-shaping controls.
Lung Volumes and DLCO
Open this first when low FVC, possible restriction, air trapping, or reduced gas transfer still need to be resolved.
Advanced Testing Modules
Use FeNO, challenge, respiratory muscle testing, or CPET only when the core pulmonary function read does not fully answer the question.
FeNO and Airway Inflammation
Bronchial Challenge Inputs
Respiratory Muscle Testing
CPET Core Interpretation Inputs
The CPET panel stays focused on variables most likely to separate deconditioning, ventilatory limitation, circulatory inefficiency, chronotropic limitation, and submaximal effort.
These advanced panels stay collapsed to protect speed at the bench and expand when the next unresolved question needs them.
ABG, Oximetry, and Safety Context
Open when oxygenation, gas exchange, or procedural caution may change whether challenge or CPET should proceed.
Serial Comparison
Use prior values when trend is clinically important, without turning the workstation into a full longitudinal database.
Clinical Readout
Priority Findings and Report Signals
Pattern
Primary physiologic classification.
Severity
Severity ladder from z-score context.
Quality
Session quality and usability.
Bronchodilator
Response status from pre/post values.
Observed and reference curve are inferred from the entered spirometry values so the operator can focus on interpretation rather than manual drawing controls.
Pre- and post-bronchodilator traces update automatically from the entered values and response pattern.
Structured Interpretation Summary
Operator Grades
Teaching Note
Advanced Testing
Serial Change
Active Interpretation Flags
Core Physiology Outputs
Severity
Lung Volumes
DLCO
Serial Comparison
Advanced Test Outputs
FeNO
Bronchial Challenge
Challenge Positivity Basis
Respiratory Muscles
CPET
ABG / Oximetry
Challenge / CPET Safety
Operator Grade Coach
Suggested FEV1 Grade
Suggested FVC Grade
Grade Difference Guide
Z-score Guide
FEV1 z-score
Enter FEV1 z-score to place it on the severity ladder.
TLC z-score
Enter TLC z-score to see whether low volume supports restriction.
DLCO z-score
Enter DLCO z-score to see how far gas transfer falls below normal.
Report Output
Structured Report Block
Short Summary
Checklist
Guideline Quick References
- FeNO adult interpretation uses ATS low/intermediate/high bands: <25 ppb, 25 to 50 ppb, and >50 ppb.
- Methacholine interpretation follows the ERS move toward delivered dose PD20 rather than concentration alone.
- Mannitol positivity is anchored to a 15% fall from baseline FEV1 or a 10% fall between consecutive doses.
- SNIP, MIP, and MEP are best judged against local lower limits of normal rather than fixed absolute numbers.
- CPET reports should stay focused on exercise capacity, ventilatory limitation, gas exchange inefficiency, circulatory pattern, and effort adequacy.