Venous and Arterial

PT (Prothrombin Time)

Measures clotting time via the extrinsic pathway.

Normal PT range

~11–13.5 sec.

INR (International Normalized Ratio)

Standardized value calculated from the PT for comparability.

Normal INR value

≈ 1.0.

Target INR for DVT/AF

2.0–3.0 (goal ~2.5).

aPTT (Activated Partial Thromboplastin Time)

Measures clotting time via the intrinsic pathway.

Normal aPTT range

21–35 sec.

Therapeutic aPTT range for heparin

1.5–2.5 × baseline.

Risk for hemorrhage aPTT value

If aPTT >100 sec.

Anti-Factor Xa Level

Alternative to aPTT for monitoring UFH.

Therapeutic Anti-Factor Xa Level

0.3–0.7 units/mL.

UFH (Unfractionated Heparin)

Indirect thrombin inhibitor; binds antithrombin III to inactivate thrombin & factor Xa.

Primary use of UFH

DVT prevention (SQ) and treatment (IV).

Route of administration for UFH

SQ for prophylaxis, IV continuous infusion for treatment.

Onset of action for UFH (IV)

Immediate.

Onset of action for UFH (SQ)

Slower onset.

Dosing strategy for UFH

Weight-based; IV via infusion pump.

Monitoring considerations for UFH

aPTT (primary) or anti-factor Xa level.

Therapeutic anti-Xa monitoring in UFH

0.3–0.7 units/mL.

Lab timing for UFH monitoring

aPTT or anti-Xa checked 6 hours after initiation and after each dose change.

Half-life of UFH

~60 minutes (IV).

Bleeding risk with UFH

HIGH if aPTT > 100 seconds.

HIT (Heparin-Induced Thrombocytopenia) risk with UFH

Higher with both Type 1 and Type 2.

Pregnancy considerations for UFH

Not preferred.

Reversal agent for UFH

Protamine sulfate.

LMWH (Low-Molecular-Weight Heparin)

Indirect thrombin inhibitor with greater anti-Xa activity.

Primary use of LMWH

Treatment of some DVT cases; VTE prophylaxis.

Dosing for LMWH

Weight-based; varies by product and institutional protocol.

Monitoring for LMWH

Not routinely required; monitor renal function.

HIT risk with LMWH

Lower risk than UFH.

Direct Thrombin Inhibitors (DTIs)

Directly inhibits thrombin to prevent conversion of fibrinogen to fibrin.

Examples of DTIs

Bivalirudin, Argatroban, Dabigatran.

Direct Factor Xa Inhibitors

Directly inhibits factor Xa to prevent clot formation.

Examples of Direct Factor Xa Inhibitors

Rivaroxaban, Apixaban, Edoxaban.

Onset of action for DTIs and Factor Xa Inhibitors

Rapid; predictable pharmacokinetics.

Monitoring for DTIs

Not routinely required; renal and hepatic function as indicated.

Reversal agent for Dabigatran

Idarucizumab (Praxbind) for emergencies.

Oral anticoagulant example

Warfarin (Coumadin).

MOA of Warfarin

Vitamin K antagonist that inhibits vitamin K-dependent clotting factors.

Primary use of Warfarin

Long-term anticoagulation for DVT, PE, AF.

Onset of Warfarin

SLOW; full effect takes 3–5 days.

Bridging therapy for Warfarin

Requires bridging with heparin until INR is therapeutic.

Drug/food interactions with Warfarin

Vitamin K can reduce effects; many drugs can enhance or reduce.

Bleeding risk with Warfarin

Narrow therapeutic window increases hemorrhage risk.

Reversal for Warfarin

Vitamin K (phytonadione); Fresh frozen plasma (FFP) for urgent reversal.

Thrombolytic therapy

Fibrinolytic agents that actively lyse and dissolve existing thrombi.

Examples of thrombolytics

Alteplase (Activase), Reteplase.

Indication for thrombolytic therapy

Reserved for life-threatening limb ischemia due to massive thrombosis.

Risks associated with thrombolytic therapy

Significantly higher bleeding risk.

Management for HIT Type 2

STOP all heparin and initiate a non-heparin anticoagulant.

4Ts scoring system

Used for pretest probability assessment of HIT.

Pharmacologic MOA of Heparins

Indirectly inhibits thrombin and factor Xa activity.

Monitoring frequency for Warfarin

Once INR is stable: weekly for 2–4 weeks, then monthly.

Indicators of HIT

Platelet count drop ≥50% from baseline.

Adjustments for renal insufficiency with LMWH

Lower doses may be required.

Patient education for anticoiougulant therapy

Educate on bleeding precautions and medication adherence.

Bleeding assessment points for anticoagulants

Monitor for gums, bruising, hematuria, melena.

Continuous monitoring requirements for UFH

aPTT or anti-Xa monitoring.

Signs of bleeding to check for

Gums, epistaxis, hematuria, bruising, tarry stools.

Importance of INR monitoring with Warfarin

Critical for safe and effective anticoagulation.

HIT Type 1 description

Mild, transient platelet decrease, prevalent in 10-20% of patients.

HIT Type 2 description

Autoimmune, severe platelet decrease, often leads to thromboemboli.

Tertiary assessments for anticoagulants

Ensure adherence to medications; assess renal function.

Signs of thrombocytopenia

Platelet count below the normal range.

Major risk factors for thrombolytic therapy complications

Older age, low body weight, uncontrolled hypertension.

Ongoing assessments during thrombolytic therapy

Monitor vital signs and neurologic status.

Urgent interventions for acute thromboembolism

Immediate clot lysis with thrombolytic agents.

Venous Thrombosis

Formation of a blood clot in a vein.

Deep Vein Thrombosis (DVT)

A specific type of venous thrombosis occurring in the deep veins, typically of the legs.

Thrombophlebitis

Inflammation of a vein associated with a blood clot.

Venous Thromboembolism (VTE)

A condition that includes both DVT and pulmonary embolism.

Phlebothrombosis

The formation of a thrombus in a vein without inflammation.

Virchow's Triad

The three factors that contribute to thrombosis: stasis of blood, vessel wall injury, and altered coagulation.

Stasis of Blood

Slowed blood flow caused by various factors like immobility or varicose veins.

Vessel Wall Injury

Damage to the blood vessel wall due to trauma or invasive procedures.

Altered Coagulation

Changes in blood coagulation factors that can increase the risk of clotting.

Hypercoagulability

An increased tendency of blood to clot, which can be due to genetic or acquired factors.

Clinical Manifestations of DVT

Symptoms include leg circumference difference, erythema, warmth, tenderness, fever, and dilated veins.

Risk Factors for DVT

Includes history of varicose veins, cancer, old age, BMI > 35, and recent major surgery.

Prevention of DVT

Strategies include use of compression stockings, exercise, and anticoagulant medications.

Medical Management of DVT

Includes heparin, oral anticoagulants, and thrombolytic therapy.

Nursing Management for DVT

Involves monitoring labs, administering medications, and promoting ambulation.

Inferior Vena Cava (IVC) Filter

A device placed in the IVC to prevent blood clots from reaching the lungs.

Varicose Veins

Enlarged veins caused by malfunctioning valves leading to blood pooling.

Clinical Manifestations of Varicose Veins

Symptoms include dull aches, muscle cramps, and lower extremity fatigue.

Diagnosis of Varicose Veins

Key diagnostic methods include venous duplex scan and air plethysmography.

Prevention Strategies for Varicose Veins

Includes avoiding tight clothing, frequent position changes, and elevating legs.

Surgical Management for Varicose Veins

Options include ligation & stripping, sclerotherapy, and ablation.

Post-Phlebitic Syndrome

A condition resulting from valve injury leading to chronic venous issues.

Clinical Manifestations of Post-Phlebitic Syndrome

Includes edema, hemosiderosis, and varicosities.

Management of Post-Phlebitic Syndrome

Strategies include leg elevation, compression stockings, and walking.

Vascular Ulcers

Ulcers that occur due to insufficient vascular supply or pressure.

Pathophysiology of Vascular Ulcers

Results primarily from increased venous pressure or ischemia.

Management of Venous Ulcers

Includes wound cleaning, debridement, and possible antibiotic treatment.

Debridement Types for Ulcers

Methods include surgical, wet-to-dry, enzymatic, and autolytic.

Lymphedema

Swelling due to accumulation of lymph fluid from obstruction or damage.

Clinical Manifestations of Lymphedema

Soft tissue swelling that progresses to firm, non-pitting edema.

Stemmer Sign

A test indicating lymphedema; inability to pinch a thin fold of skin.

Management of Lymphedema

Includes compression, exercise, and potential surgical intervention.

Cellulitis

An acute bacterial skin infection characterized by inflammation.