# Perioperative anticoagulation

> Perioperative anticoagulation is the plan for a patient's blood-thinning medication around surgery. Most anticoagulants are withheld beforehand to reduce bleeding risk, balanced against the thrombotic risk of stopping them. Because the timing depends on the drug, the procedure and kidney function, the plan has to be made days ahead — which requires knowing the patient is taking one.

*Source: https://getpathways.ai/glossary/perioperative-anticoagulation*

Also known as: anticoagulant management, blood thinners before surgery, bridging

- **Drug classes**: Direct oral anticoagulants, vitamin K antagonists, antiplatelet agents
- **Core trade-off**: Bleeding risk if continued against thrombotic risk if stopped
- **Timing depends on**: The specific drug, the procedure's bleeding risk, and renal function
- **Why it is missed**: Patients describe them loosely; referral letters and GP summaries go stale

## The trade-off

Anticoagulation exists because the patient is at risk of clotting — atrial
fibrillation, a mechanical valve, a previous venous thromboembolism. Stopping
it removes that protection. Continuing it through a procedure raises the risk
of bleeding, which for some operations is unacceptable and for others barely
matters.

Neither side of that trade-off can be decided generically. It depends on which
drug, the bleeding risk of the specific procedure, and — for the direct oral
anticoagulants, which are largely cleared renally — how well the patient's
kidneys work.

## Why it is a scheduling problem

Whatever the plan turns out to be, it has to start before the day of surgery.
That makes it a booking-time decision rather than an admission-time one. A
patient who arrives having taken their anticoagulant that morning cannot be
made safe by anything decided in the holding bay.

## Why the medication is so often unknown

This is where it fails in practice. Anticoagulants are among the drugs patients
are least able to name — they are frequently described as "a blood thinner" or
by a brand the patient half-remembers, and an eight-month-old GP summary may
predate the prescription entirely.

Pathways addresses this by having patients photograph their medication boxes
during the interview. Each image is read, classified, and the extracted values
verified against the source before entering the record, then cross-checked
against the referral history. The staged example in the product shows exactly
this case: an apixaban absent from the GP summary, extracted from a box photo
and flagged for clinician review.