Non pharmacological method for

prevention and treatment of DVT

Dr L.M.Darlong. MS,FIAGES,FMASNorth-eastern Indira Gandhi Regional Institute of health and medical sciences (NEIGRIHMS). Shillong. India

DVT

• An intravascular deposit composed of fibrin and red blood cells with a variable platelet and leucocyte component.

• Occurs in region of slow blood flow

• Pulmonary embolism -fragment of this clot breaks and migrates to the lung and lodges in the pulmonary artery or its branch.– Most severe complication-

Cause • Usually not

known• Universally

attributed to Virchows triad

– STASIS – HYPERCOAGUL

ABILITY– INTIMAL INJURY

VenousVenousStasisStasis

Tourniquet

Immobilization and bed rest

VascularVascularInjuryInjury

Surgical manipulation of the limb

Endothelial injury

HypercoagulabilityHypercoagulability Increase in thromboplastin

agents

Natural History of DVT

• Without treatment, approx 20 to 25% of calf vein thrombi extend into the popliteal and femoral veins causing proximal DVT.

• Without treatment approximately half of patients with proximal DVT develop PE

• (Hull, RD, (Hull, RD, Raskob Raskob, GE, Hirsh, J Prophylaxis of venous thromboembolism : an overview.

• Chest1986;89,374S

Natural History ofPulmonary Embolism

• The mortality rate of patients treated for pulmonary embolism has decreased from 8% to < 5%.

• The majority of deaths due to PE ( ie > 90%) occur in pts who are not treated because the diagnosis is not made.

Prevention

• Prevention of pulmonary embolism is of paramount importance because the disorder is difficult to detect, and treatment of established pulmonary embolism is not universally successful.

DVT risk stratification for surgery patients

• Low risk Low• Uncomplicated surgery in patients aged <40 years with

minimal immobility postoperatively and no risk factors factors

• Moderate risk • Minor surg in pt with additional risk factor• Surg in 40-60 yrs with no additional risk factor• High risk• Surgery in patients aged >60 years,or 40-60 yrs with

additional risk factor• Very high risk• Surgery in patients with multiple risk factor (>40

years,previous venous thromboembolism,cancer or known hypercoagulable state)

• Major orthopedic surgery ( hip/knee arthroplasty)• elective neurosurgery• multiple trauma• spinal cord injury

What Are We Trying To Prevent?

• Asymptomatic DVT?

• Symptomatic DVT?

• All PE’s?

• Fatal PE’s?

• Post-phlebitic Syndrome?

Mechanism of action

• Stasis – Nonpharmacologic

• Hypercoagulable – Blood thinning agents

( Pharmacologic agents )

• Intimal injury – Minimal trauma / Tissue handling ( Non-Pharmacologic )

Non-Pharmacologic

• Early ambulation remains the most important nonpharmacologic

Mechanism

• Augmentation of venous blood flow in the lower limbs via external mechanical devices.- Decreases venous stasis.

• Venous compression secondary to external compression device results in the release of Plasminogen (Natural fibrinolytic ) and Nitric oxide ( Vasodilator) into the blood stream from the endothelial layer of the vein.

• Inferior vena caval filter ( IVC filter ); This are mechanical devices to trap blood clots arising from the lower limb and prevent them from traveling to the pulmonary circulation.

Non-Pharmacologic

Early ambulation

• Should be routine part of all postop care – Unless absolute contraindicated

• Acceptable as VTE prophylaxis for low risk surgical patients

Elastic stockings

• Improved venous flow ,reduce vessel wall damage caused by passive venous dilatation ,during surgery

• Applied preop and continued throughout the hospital

• Recommended as adjunct in moderate and high risk case

• Avoid improper fitting stockings

-Pneumatic Compression Devices (PCD) VasoPress

-Sequential Compression Devices (SCD) Kendall

• Intermittent regimen that delivers a sustained pressure in distal to proximal manner.

• The difference-Compartments in PCD devices are uniformly inflated to the same pressure rather than in a graded-sequential fashion as in SCD devices.

Intermittent Pneumatic Compression

IPC

• Intermittently inflates and deflates bladders contained within the garment (20-40 mmHg).

• Cycle times vary from manufacturer to manufacturer.

• Typically, the inflation (compression) cycle is 10-15 seconds with a 45-50 second relaxation (rest)

Intermittent Pneumatic Compression

• Direct pumping effect- Reduce stasis• Promotes clearance of local pro

thrombo clotting factor, increase local plasminogen activators

• Obese individual – Doubtful• Only effective used continously-

nonambulat• Presumed additive prophylactic effect

– pharmacologic

IPC

•Intraop and postop IPC is specific localized prophylaxis:

– Decreased venous stasis • increase venous velocity• increase venous volume

– Inhibits coagulation cascade• tissue factor pathway inhibitor• factor VIIa• NO and endogenous

NO synthase•

• Wide variety of devices– foot pump– calf– thigh-calf

Not recommended – Sole agent

• High risk – Gen Surgical pt• High risk – Urology surg pt• Orthopaedics –Hip or knee surgery

Method of choice when pt at increased risk of bleeding with anticoagulants

Solo thromboprophylaxis for moderate to high risk gynae surg

Current accepted indications• Absolute contra to anticoagulant• Life threatening hemorrhage on

anticoagulant• Failure of adequate anticoagulation

Prophylactic filter not recommended

It is an invasive procedure

IVC Filter

Recommendation Air TravelLong distance travel ( >6 h duration):.Avoid constrictive clothing.around lower extremities / waist .Avoid dehydration.Do frequent calf muscle stretching

Additional risk factors .If active prophylaxis/perceived increased risk .Suggest the use of properly fitted, below-knee GCS,providing 15 to 30 mm Hg of pressure at the ankle

Non pharmacologic management of PE

Catheter extraction or fragmentation for the initial rx of

PE

• Against use of mechanical approaches for most pts with PE.

• Use selected highly compromised pts who are unable to receive thrombolytic therapy or whose critical status does not allow sufficient time to infuse thrombolytic therapy

» Mortality of aprox 20-30%

Pulmonary embolectomyfor the initial treatment of PE

• Pulmonary embolectomy continues to be performed in emergency situations when more conservative measures have failed.

• If it is attempted the following criteria req:– 1) massive PE (angiographically documented if

possible)– 2) hemodynamic instability (shock) despite

heparin, resuscitative efforts;– 3) failure of thrombolytic therapy or a

contraindication to its use.

• Operative mortality from 10 to 75% in uncontrolled retrospective case series. (in the era of immediately available cardiopulmonary bypass has )

Risk Factor-Short-term (30-day) postoperative

• > 50 years • Varicose veins • Myocardial

infarction • Cancer • Atrial fibrillation • Ischemic stroke • Diabetes mellitus

• Other additional factors• -DVT• -heart failure• -Obesity• -paralysis,

• inherited conditions, • -factor V Leiden • -prothrombin gene

mutation,• -protein S deficiency• -protein C deficiency• -antithrombin

deficiency.

Barriers in DVT

• Routinely assess the risk / Asses as risk factor for heart disease.

• Encourage routine prophylaxis for pt at risk

• Prophylaxis underused – Consensus APHA.

• Lack of awareness of DVT risk• Percieved diff in risk asses and

percieved risk of bleed with prophylaxis

ACCP Recommendation

• Primarily in patients who are at high risk of bleeding

• Adjunct to anticoagulant-based prophylaxis

• Careful attention be directed toward ensuring the proper use of, and optimal compliance with, the mechanical device

Thank you