H2 - Lab- 3 - Bleeding Time, Capillary Fragility, Clot Retraction - Complete

Bleeding time

This test measures the In vivo measurement of the platelet adhesion, and aggregation to a locally injured vascular sub-endothelium

Factor VIII-vWF complex, GP Ib/IX complex

The presence of these complexes are necessary for platelet adhesion to occur

Bleeding time

It is the initial test for patients suspected of having congenital platelet abnormality or vWD

Primary platelet plug, Vasoconstriction

Bleeding time is dependent on the formation of this end product in primary hemostasis (#1), and the initial event that happens upon injury of the blood vessel wall (#2)

Aspirin, Non-steroidal Anti-inflammatory drugs

Medications that prolong bleeding time

Anti-platelet effect

What effect does Aspirin have on platelets?

Cyclooxygenase

Aspirin inhibits the catalytic activity of what enzyme?

Thromboxane A2

Aspirin inhibits cyclooxygenase, which leads to the inhibition of the synthesis of what platelet agonist?

1 week

Patients taking Aspirin should discontinue ingestion for how long prior to the bleeding time test?

Ibuprofen, Naproxen, Tolmetin sodium, Ticlopedine

Examples of Non-steroidal Anti-inflammatory drugs

24 hours

Patients taking NSAIDs are asked to discontinue ingestion for how long prior to the bleeding time procedure?

Keloid formation

Before starting the bleeding time procedure, the patient should be informed of the possible formation of this type of scarring on their site of incision.

Duke method, Ivy method, Template method

Methods for bleeding time

Feather lancet

Duke method materials used

Earlobe, Fingertip

Duke method site of puncture

Lancet size-dependent

Duke method incision size

5 minutes

Duke method normal value

Every 30 seconds

Duke method frequency of wicking blood using Whatman filter paper #2

Feather lancet, Blood pressure cuff

Ivy method materials used

40 millimeters of Mercury

Ivy method BP cuff pressure used

Blood pressure cuff

What equipment used in the Ivy method makes it standardized?

Volar surface of the forearm 5 centimeters below the antecubital crease

Ivy method site of puncture

Free of veins, scars, bruise, hairs, swelling

Ivy method site of puncture requirement

Parallel to the antecubital crease (3.5mm), Lancet-size dependent

Ivy method incision size

2.5-7 minutes

Ivy method normal value

Modified Ivy method

Other name for Template method

Melke et al.

They modified the Ivy method, making Template method

Disposable template device, Blood pressure cuff

Template method materials used

40 millimeters of Mercury

Template method BP cuff pressure used

Volar surface of the forearm 5 centimeters below the antecubital crease

Template method site of puncture

Parallel

Template method incision direction that is more sensitive

Perpendicular

Template method incision direction that produces less scar formation

Parallel

Template method incision direction that tends to prolong bleeding time

Parallel

Template method incision direction most commonly used

5 mm long, 1 mm deep

Template method incision size for adults

3.5 mm long, 1mm deep

Template method incision size for pediatrics

White

Surgicutt device color used for adults

Pink

Surgicutt device color used for pediatrics

2-8 minutes

Template method normal value

Whatman filter paper #2

Filter paper used in bleeding time

Wicking

It is the action of blotting the bleeding time incision site with filter paper without touching the incision.

Primary platelet plug formation

Wicking of filter paper for bleeding time is done to avoid disturbing the formation of what product in hemostasis?

30-60 seconds after

After the BP cuff is inflated on the patient's arm in preparation for bleeding time, the procedure should be started after how many seconds?

Note: The timer should also start together with incision

Every 30 seconds

How often is the incision site blotted using Whatman filter paper in bleeding time?

Simplate device

Identify template device.

Its blade remains outside and does not retract. It can either be one or two-blade.

Guillotine-like cut

Incision made by Simplate device

Surgicutt device

Identify template device.

Slicing action

Incision made by Surgicutt device

Surgicutt device

Template device with blade with automatically retracts

Perpendicular to elbow crease

Template method incision direction for infants <4 months

20 millimeters of Mercury

BP cuff pressure for newborns <2 lbs

25 millimeters of Mercury

BP cuff pressure for newborns 2-4 lbs

30 millimeters of Mercury

BP cuff pressure for newborns >4 lbs

Anemia

Red blood cell condition that prolongs bleeding time

Inversely proportional

What is the relationship of the amount of platelets to bleeding time result?

Thrombocytopenia

Platelet condition that prolongs bleeding time

Aspirin, Non-steroidal Anti-inflammatory drugs, Antibiotics like Penicillin and Cephalothin

Medications that prolong bleeding time

von Willebrand's disease, Glanzmann thrombasthenia, Bernard-Soulier syndrome, Congenital storage pool disease

Clinical conditions that prolong bleeding time

von Willebrand's disease

Bleeding disorder with the absence of von Willebrand factor

Glanzmann thrombasthenia

Bleeding disorder due to qualitative platelet defect — Platelet aggregation defect

GP IIb-IIIa complex deficiency

Platelet defect in Glanzmann thrombasthenia

Fibrinogen

GP IIb-IIIa complex is a binding site for what coagulation factor?

Bernard-Soulier syndrome

Qualitative platelet defect that prolongs bleeding time. — Platelet adhesion defect

GP Ib/IX complex deficiency

Platelet defect in Bernard-Soulier syndrome

von Willebrand Factor

GP Ib/IX complex is a receptor for what substance?

GP Ib

What portion of the GP Ib/IX complex is missing in Bernard-Soulier syndrome?

Hermansky-Pudlak syndrome

Other name for Congenital storage pool disease

Preoperative screening

Procedure where bleeding time has no predictive value

Neurosurgical and intraocular procedures

Procedures where bleeding time has predictive value

Discontinue test

If bleeding time exceeds 15 minutes using the Ivy method, what should be the next appropriate course of action?

4' 33''

If bleeding time is 4 minutes and 33 seconds, what is the proper way of writing it down?

Capillary fragility test

This test detects the ability of the small blood vessels to retain RBCs in their lumen under conditions of stress and trauma

Positive pressure

What pressure is utilized in the Capillary fragility test so that small blood vessels undergo stress and trauma?

Tourniquet test, Rumpel-Leede test

Other names for Capillary fragility test

Petechiae formation

Capillary fragility test positive result

Petechiae

These are minute hemorhages in the skin near the site where pressure is applied; indicates bleeding in the skin

Thrombocytopenia, Decreased fibrinogen, Vascular purpura

Conditions with positive tourniquet test

Tourniquet test, Elliot method

Methods used for capillary fragility test

Rumpel-Leede test

Other name for Tourniquet test

Positive pressure

Tourniquet test pressure used

Stethoscope, Blood pressure cuff

Tourniquet test materials used

80 millimeters of Mercury

Tourniquet test BP cuff pressure

5 minutes

Tourniquet test BP cuff duration

Tourniquet

This is used in place of the BP cuff in the Tourniquet test

15 minutes

How long is the BP cuff or tourniquet applied for in the Tourniquet test?

1/2 inch

Petechiae within this distance of the BP cuff in the tourniquet test should be disgarded.

7 days

How many days after can you perform the tourniquet test on the same arm?

False positive

Tourniquet test result if done on the same arm within 7 days

<10 fresh petechiae

Tourniquet test negative result

10-20 fresh petechiae

Tourniquet test borderline result

>20 fresh petechiae

Tourniquet test positive result

Elliot method

Capillary fragility test method that uses negative pressure

Negative pressure

Pressure used in the Elliot method

Suction cups, Petechiometer

Elliot method equipment used

15-20 millimeters of Mercury, 1 minute

Elliot method suction pressure and duration

0-10 fresh petechiae

Elliot method negative result

>10 fresh petechiae

Elliot method positive result

Thrombocytopenia, Glanzmann thrombasthenia, Scurvy, Women before and during menstruation, Women >40 years old

Conditions that exhibit positive capillary fragility test

Idiopathic Thrombocytopenic Purpura, Drug-induced, Immune-induced

Conditions that cause thrombocytopenia resulting in positive capillary fragility test

Scurvy

What condition shows a normal platelet count and a positive capillary fragility test?