Required section · Section 5 of 6

Your decision: rank the evidence, choose the action

A second adult outpatient presents with epistaxis since childhood and heavy menstrual bleeding, now scheduled for a dental extraction. There is no reported joint or deep muscle bleeding. Results: platelet count 232 x10^9/L (150-400 x10^9/L), PT 12.1 s (10.5-13.5 s), aPTT 29.8 s (25.0-35.0 s), Clauss fibrinogen 301 mg/dL (200-400 mg/dL). The citrate tube is full and unclotted, drawn by peripheral venipuncture, no analyzer flags. No anticoagulant or NSAID use is reported.

Identify the evidence that matters, choose the next laboratory action, and place specimen review, bleeding history, pattern classification, and targeted follow-up in the correct order.

This decision is scored on the evidence you select and the action you choose, not on whether you can name a disease from four screening numbers. A confident diagnosis at this stage would outrun what a screen alone can support.

Work the sequence in order, every time, even when the screen looks unremarkable, because skipping a step is how a real pattern gets missed.

Ordering exercise

Put the bleeding-disorder screening work-up in the correct working order for the second case above.

1. Classify the screening pattern

Read platelet count, PT, aPTT, and fibrinogen together as one of the five recognizable patterns.
2. Select the targeted follow-up test

Order or refer for the one study, such as VWF antigen and activity, that best narrows the confirmed pattern.
3. Document the bleeding history

Record site, timing, family history, and medication/supplement use, including any anticoagulant.
4. Verify specimen quality and anticoagulant exposure

Confirm tube fill and clotting status, hematocrit, and check for heparin or anticoagulant interference before assigning a pattern.

Knowledge checks

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Knowledge check 1

For the second case (lifelong epistaxis, heavy menstrual bleeding, normal platelet count, PT, aPTT, and fibrinogen, acceptable specimen, no anticoagulant or NSAID use), what is the single best next laboratory action?

Choose one option.

Obtain or refer for VWF antigen, platelet-dependent VWF activity, and factor VIII coagulant activity

Report the screen as normal and close the case

Order a 1:1 mixing study since the screen is otherwise unremarkable

Knowledge check 2

A prolonged aPTT is mixed 1:1 with normal pooled plasma. Which statements correctly describe interpretation after specimen quality and anticoagulant exposure have been reviewed? Select all that apply.

Choose at least 1 options.

In a specimen without anticoagulant interference, correction toward the laboratory's criterion supports a factor deficiency

Failure to correct can reflect an inhibitor or anticoagulant interference

The correction cutoff is a universal value that applies at any laboratory

Immediate correction followed by prolongation after incubation can support a time-dependent inhibitor after drug interference is excluded

Section status

Finish this section

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The module finishes after every required section is marked done and every check in those sections is correct.