Custom GPT: Your Personal RT Clinical Assistant

What This Builds

You'll create a Custom GPT — a purpose-built AI assistant that already knows your specialty, speaks your clinical language, and is pre-loaded with the reference materials you consult most: AARC guidelines, ventilator weaning criteria, ABG interpretation frameworks, and your department's common protocol parameters. Instead of re-explaining your context every time you open ChatGPT, this assistant already knows you're an RT and jumps straight to clinically relevant answers.

Prerequisites

• ChatGPT Plus or Pro subscription ({{tool:ChatGPT.price}}/month) — Custom GPTs require a paid plan
• Comfortable using ChatGPT for basic tasks (see Level 3 ABG guide)
• 1–2 hours for initial setup; 15 minutes to load reference materials

The Concept

A Custom GPT is like hiring a specialized clinical librarian who has read every AARC guideline, knows what an ICU RT does all day, and never forgets your preferred communication style. You set it up once by writing a system prompt that defines the assistant's role, knowledge, and personality. Every conversation starts from that shared understanding — no more re-explaining that you're an RT and you need practical bedside answers, not generic medical summaries.

Think of it as a knowledgeable colleague who is always available, never condescending, and answers in exactly the format you need during a busy shift.

Build It Step by Step

Part 1: Create the Custom GPT

1. Go to chatgpt.com and log in to your Plus account
2. Click your profile icon (top right) → My GPTs
3. Click Create a GPT (top right button)
4. You'll see the GPT Builder interface: a conversation panel on the left and a preview on the right

Part 2: Write the System Instructions

In the GPT Builder, click Configure (tab at the top). You'll see fields for Name, Description, and Instructions. Fill in:

Name: RT Clinical Assistant

Description: Clinical reference tool for respiratory therapists — ABG interpretation, guideline summaries, protocol templates, patient education drafts, and documentation support.

Instructions (paste this entire block):

You are a clinical reference assistant for respiratory therapists working in acute care settings (adult ICU, ED, general floors). You have deep knowledge of:

- ABG interpretation (acid-base disorders, oxygenation assessment, PaO2/FiO2 ratio, A-a gradient)
- Mechanical ventilation (AC/VC, AC/PC, PRVC, SIMV, PS modes; PEEP, FiO2, tidal volume, lung-protective strategies)
- AARC clinical practice guidelines (mechanical ventilation liberation, HFNC, NIV, aerosol therapy, bronchial hygiene)
- ARDS Network lung-protective ventilation protocol
- Spontaneous breathing trial criteria and liberation from mechanical ventilation
- HFNC use: indications, flow rates, FiO2, ROX index monitoring
- NIV (CPAP, BiPAP): modes, settings, indications and contraindications
- Home respiratory therapy: CPAP, BiPAP, home oxygen criteria, nebulizer therapy
- Medicare/insurance coverage criteria for home respiratory equipment
- NBRC credentialing: RRT, NPS, ACCS, SDS exam content

When answering:
- Lead with the practical clinical answer first — avoid lengthy preamble
- Use specific numerical thresholds (e.g., "SBT failure: RR >35, SpO2 <90%, accessory muscle use")
- Format reference summaries as bulleted clinical cards, not paragraphs
- For ABG interpretation, always walk through: primary disorder → compensation → oxygenation → PF ratio → clinical implications
- If asked about something that may have changed since your training, flag it and recommend verifying against the most recent AARC/ATS publication
- Never give patient-specific treatment orders — you assist with clinical reasoning and reference, not direct care decisions
- For documentation drafts, write in clinical language appropriate for hospital chart entries

Your user is a working RT who needs fast, accurate, practical answers — not an exhaustive literature review.

Part 3: Load Reference Materials (Optional but Powerful)

In the Configure tab, scroll down to Knowledge. Click Upload files. You can upload PDF or text files that Claude will reference when answering questions:

Suggested files to upload:

• AARC Clinical Practice Guidelines (downloadable from aarc.org — the ventilator liberation guideline is especially useful)
• Your department's ventilator weaning protocol (ask your director for the approved PDF)
• The ARDS Network ventilator management table (available at ardsnet.org)

Once uploaded, your Custom GPT will reference these specific documents when answering questions about protocols — giving you institution-specific answers rather than generic ones.

Part 4: Set Conversation Starters

Still in Configure, scroll to Conversation starters. Add these so you can tap them instead of typing:

• "Interpret this ABG:"
• "What are the SBT criteria?"
• "Summarize the HFNC failure criteria"
• "Draft a patient education handout for:"
• "Write an insurance authorization letter for:"

Part 5: Test and Refine

1. Switch to the Preview tab (right side of builder)
2. Try a few real clinical questions:

   • "pH 7.24, PaCO2 62, HCO3 25, PaO2 58 on FiO2 0.50. Interpret and recommend vent changes."
   • "What are the current AARC criteria for starting an SBT?"
   • "Draft a CPAP education handout for a new sleep apnea patient."
3. If answers are too generic, go back to Instructions and add more specificity
4. Click Save when satisfied — give it a public or private setting (choose Private for personal use)

Real Example: ICU Evening Shift

Setup: You've loaded the ARDS Network protocol and your ICU's weaning protocol into the GPT's Knowledge files.

Input (what you type): "Patient on AC/VC, rate 14, TV 450, PEEP 10, FiO2 0.55. Weight 75kg IBW. Last ABG: pH 7.38, PaCO2 44, HCO3 25, PaO2 88. SpO2 96%. P/F ratio?"

Output (what the GPT returns):

• P/F ratio: 160 — moderate ARDS range (100–200)
• TV at 450mL/75kg IBW = 6.0 mL/kg — appropriate per ARDSNet protocol
• Acid-base: normal, well-compensated
• Oxygenation: acceptable but limited. Consider FiO2 wean to 0.50 if SpO2 stable above 94%
• Recommendation: maintain current TV, trial FiO2 wean, monitor driving pressure (target ≤15 cmH2O)

Time saved: 5 minutes of mental calculation and reference check → 20-second query

What to Do When It Breaks

• Answer too generic → Add more specifics to the Instructions; upload your department's protocols to Knowledge
• Doesn't use uploaded files → Ask explicitly: "Based on the AARC guideline I uploaded, what are the criteria for..."
• Incorrect threshold cited → Always verify critical thresholds against primary sources; report the error so you know to cross-check similar answers
• Conversation gets long and loses context → Start a new conversation — Custom GPTs reset context between sessions

Variations

• Simpler version: Just save a detailed system prompt as a note and paste it at the start of each regular ChatGPT conversation — no paid account needed, but you'll need to paste each time
• Extended version: Upload all your department policies, the latest CHEST guidelines, and your equipment manuals — the GPT becomes a department-specific protocol reference

What to Do Next

• This week: Build the base GPT with the system instructions, run 10 test queries
• This month: Upload 2–3 reference documents from your department and refine the instructions based on what the GPT gets wrong
• Advanced: Share the GPT (set to "Anyone with a link") with your charge RT team so everyone has the same reference tool

Advanced guide for respiratory therapist professionals. Custom GPTs require a ChatGPT Plus subscription ({{tool:ChatGPT.price}}/month).