June 6, 2026 7 min readBy Dennis Diaz, CRNA

AI Anesthesia Pre-Op Charting: How It Actually Works

Under the hood of AI pre-op charting in 2026. The five stages a clearance document goes through — and what each one is actually doing.

Most anesthesia AI demos hand-wave through the part where the magic happens. Here's the actual pipeline a clearance document goes through, with no marketing varnish.

Stage 1: Document ingestion

A clearance comes in as a PDF, a phone photo, or a fax converted to PDF. Stage 1 normalizes the file: OCR for scanned content, layout extraction for typed documents, image enhancement for low-quality phone photos. The output of stage 1 is searchable text with structural metadata (this is the H&P heading, this is the medication list section, this is a lab table).

Stage 2: Structured field extraction

Structured fields — lab values, medication names with doses, ICD codes, allergies — are extracted with field-aware parsing. This is where the lab fishbone gets populated: WBC, Hgb, Hct, plt for the X; Na/K/Cl/CO2/BUN/Cr/glucose for the BMP grid; PT/INR/PTT for the coag Y. This stage is closer to traditional NLP than to LLM work — high reliability, narrow scope.

Stage 3: Clinical narrative interpretation

The H&P body, specialist notes, and discharge summaries are interpreted by an LLM with explicit instructions to identify ASA-relevant comorbidities, hold implications for current medications, recent events that affect anesthetic plan, and any explicit specialist recommendations. This is the stage where the model's clinical training actually matters — generic LLMs without anesthesia tuning miss the things that matter (GLP-1 hold timing, the three G's for bleeding risk, the ASA II/III cusp criteria).

Stage 4: Clinical rule application

With a structured patient record in hand, the system applies clinical rules: hemoglobin cutoffs by case type, GLP-1 hold verification, BP control assessment, urinalysis screening before implant cases, anticoagulant hold protocol checks. Each rule emits a flag with severity (red, yellow, green) and a rationale. The rule set is the product of years of guideline curation (ASA, ACC/AHA, ASRA) — this is where domain knowledge separates real anesthesia AI from generic medical AI.

Stage 5: Verdict synthesis and two-section PDF

The aggregated flags drive the final verdict: Cleared, Cleared with Conditions, or Not Cleared. The PDF generates two sections: plain language for the coordinator ("please verify the patient held Ozempic for 14 days") and clinical detail for the anesthesia provider (rationale, citations, recommended pre-op orders). The Anesthesia Pre-Op Form is populated from the same structured record in parallel.

Stage 6 (manual): Clinician sign-off

The provider reviews the output. Every flag can be overridden. The verdict can be revised. The chart is signed by a human under the human's license. This is the stage that AI tools cannot and should not skip.

If you want to see this end-to-end on a real case, sign up for MyPreOp.ai and upload one clearance. See the platform overview, the live validation study, or read the walkthrough of the AANA P-1 pre-op form.