ORAL SURGERY IN PATIENTS ON

ANTICOAGULANT THERAPY

Presented by-

Dr. Varun Mittal, PG

Dept of Maxillofacial Surgery

SRM DENTAL COLLEGE, CHENNAI, INDIA

Which all patients?

Mostly cardiac or vascular disorders:

Atrial fibrillation

Ischemic cardiac disease

Cardiac valvular disease

Prosthetic cardiac valves

Post myocardial infarction

Deep venous thrombosis

Pulmonary embolism

Cerebrovascular accident

ANTICOAGULANTS… Used in vitro:-

A. Heparin

B. Calcium complexing agents eg. Sodium

citrate (for storing blood for transfusion

purposes); Sodium oxalate & sodium etedate

Used in vivo:-

A. Heparin, low mol weight heparin

B. Oral anticoagulantsI. COUMARIN DERIVATIVES- WARFARIN SOD.

II. INDANDIONE DERIVATIVE- PHENINDIONE

ASPIRIN (NSAID)

MECHANISM OF ACTION…HEPARIN- indirectly activates plasma

antithrombin III (AT III, serine

proteinase inhibitor)

↓Heparin-AT III complex binds to clotting factors of intrinsic & extrinsic pathways (Xa, IIa, IXa, XIa, XIIa & XIIIa)

↓Inactivates all factors except VIIa ; factor of extrinsic pathway

↓At low concs fac-Xa mediated conversion of prothrombin → thrombin is selectively affected → anticoagulant action is mediated mainly by inhibition of fac-Xa & thrombin IIa mediated conversion of fibrinogen→fibrinLOW CONCS- prolongs aPTT without significantly prolonging PT.HIGH CONCS- prolong both

LOW MOL WEIGHT HEPARINS-

Selectively inhibit fac-Xa with little

effect on IIa↓

Act only by inducing confirmational change in AT III and not by bringing together

↓So LMW heparins have smaller effect on a PTT & whole blood clotting time

↓Lesser antiplatelet action & less interference with hemostasis

↓Lower incidence of hemorrhagic complications

Oral Anticoagulants..

WARFARIN Na:-

Indirectly by interfering with synthesis of vit-K

dependent clotting factors in liver (competitive antagonists of vit-K)→ ↑PT & APTT

ASPIRIN:- Inhibits COX pathway;

Inhibits ADP release from platelets

INR & Its Implications…

INR is the PT ratio (patient PT/control PT) or

obtained if international reference

thromboplastin reagent had been used

This test is performed by adding calcium and

tissue thromboplastin to citrated plasma to

activate the coagulation cascade and time

required for clotting to occur is the

Prothrombin time(PT)

Normal PT range INR is 1

INR = (patient PT/mean normal PT) IsI

Recommended therapeutic range

for oral anticoagulant therapy..

CLINICAL STATE PT RATIO INR

Prophylaxis

-DEEP VEIN THROBOSIS 1.3-1.5 2-3

Treatment of initial episode

-PE & DVT 1.3-1.5 2-3

Prevention of systemic embolism

-AF with systemic emboli

- Valvular heart disease

-Tissue heart valves & Ac. MI

1.3-1.5

1.3-1.5

1.3-1.5

2-3

2-3

2-3

Mechanical heart valves 1.5-1.8 3-4.5

Recurrent systemic embolism 1.5-1.8 3-4.5

AF with systemic emboli

Coronary artery bypass graft (CAPG) 1.5-1.8 3-4.5

Overall management

Type of surgical procedure

INR value

Presence of other risk factors Aspirin intake

Presence of coagulopathy/liver disease

Alcohol intake

Traumatic surgery

Coumadin effect enhancing medicines

Clinical judgement

Patients on Warfarin therapy.. With review of the available literature, no well-

documented cases of serious bleeding problems

from dental surgery in patients receiving

therapeutic levels (1.5 to 2.5 times of control) of

continuous warfarin sodium therapy were

identified.However several documented cases of

stopping warfarin before surgery led to rebound

thrombosis, damaged prosthetic cardiac valves

and caused deaths in dental patients.

(Wahl MJ. Dental surgery in anticoagulated

patients. Arch Intern Med 1998;158:1610-6)

Management of warfarin

patients1. Low-risk procedures required no change in

anticoagulation medication.

2. Moderate-risk procedures indicated withdrawal

of coumarin 2 days before the procedure and

verification of INR on the day of the procedure.

3. For high-risk dental procedures, a heparin

protocol was strongly recommended.

Uncomplicated forceps extraction of 1 to 3

teeth with INR <3.5 & no other risk Without adjustment of coumadin dose with

local/topical measures

Local methods

1. RESORBABLE GELATIN SPONGE & SUTURE

2. FIBRIN GLUE

3. TRANEXAMIC ACID

1 alone, 1+3, 1+2

However in a comparable study local hemostasis with gelatin sponge and sutures is found sufficient in a study on 150 patients when INR is 1.5-4.0. (Dental extractions in patients maintained on continued oral anticoagulant. Comparison of local hemostaticmodalities. Danielle et al OOOR 1999)

With >simple/minor surgery >3.5 &

presence of other risk factors

1. Hospital & evaluation of bleeding tendency

2. Physician opinion & modification of

anticoagulant therapy to heparin pre-op

3. Generally stopping of Warfarin 2day before

surgery is considered best.

4. For prevention of post-op bleeding Tranexamic

acid used topically.

Guidelines for warfarin therapy after surgery

*Day 1: Obtain baseline INR.

Start warfarin with 10-mg dose on night of surgery. Use

lower doses (2 to 5 mg) if patient is elderly, chronically

malnourished, has liver disease, or is on medication that

can potentiate warfarin. Alternatively, can use patient’s

known usual maintenance dose.

†Day 2: Check INR (reflects first dose only).

If INR 1.5, give same dose.

If INR 1.5, give lower dose.

‡Day 3: Check INR (reflects first 2 doses).

INR 1.5 suggests higher than average maintenance

dose (>5 mg) will be necessary.

INR is 1.5 to 2.0 suggests average maintenance dose

(approximately 5 mg) will be necessary.

INR 2.0 suggests lower than average maintenance

dose (<5 mg) will be necessary

Post-op care…

Antifibrinolytics

Tranexamic acid topical mouthwash

EACA(250mg/ml)25% syrup 5 to 10 ml

Oral penicillins V 250 to 500mg qid for 7 days

Paracetamol choice drug for short term use as

no affect on platelets OR Codeine is also

effective

Diet cool liquid and minced solids for several

days

3- double blind randomized controlled trials of topical

tranexamic acid as 4.8 to 5% for 2 min, 4 times for 7

days after extraction showing bleeding >20 min

Patients Patients Control

Gp

Control

Gp

First author Year Number Bleeding Number Bleeding

Sindet-

Pederson

1989 19 5.3% 20 40%

Borea 1993 15 6.7% 15 13.3%

Ramstrom 1993 44 0 45 22.2%

Post-op prolonged bleeding

Biting on a gauze pad soaked in Tranexamic

acid or a moist tea bag for 30 min, firmly

Need for infusion should be assessed

Desmopressin acetate synthetic analogue of

vasopressin initiates release of fac VIIIC, vW

fac & t-PA from storage site of endothelium

Given as intranasal spray (1.5mg/mL with each 0.1mL pump spray delivering 100- to 150- μg)

Management of patients on heparin

anticoagulation therapy

Heparin has an immediate effect on blood

clotting but acts for only 4 to 6 hours. The effect

of heparin is best assessed by the APTT. For

uncomplicated forceps extraction of 1 to 3 teeth,

there is usually no need to interfere with

anticoagulant treatment involving heparin or

LMW heparins or antiplatelet drugs. Medical

consultation should be sought before more

advanced surgery in a patient with heparin

treatment

Initiation and modification of heparin therapy

1.One to 2 days before hospitalization, discontinue

coumadin.

2. Check baseline APTT, INR, complete blood cell/platelet

count.

3. Give bolus of heparin at dose of 80 U/kg intravenously.

4. Start drip infusion of heparin at 18 U/kg/h intravenously.

5. Check APTT 6 hours after initial bolus of heparin.

6. Adjust dose of heparin as per sliding scale:

APTT <35 seconds 80 U/kg bolus;↑ drip by 4 U/kg/h

APTT 35-45 seconds 40 U/kg bolus;↑ drip by 2 U/kg/h

APTT 46-70 seconds. No change because level is

therapeutic

APTT 71- 90 seconds Reduce drip by 2 U/kg/h

Guidelines for monitoring heparin therapy

1.Check APTT 6 hours after initial bolus and 6 hours after

any

dose change. Adjust heparin infusion as per sliding

scale

guidelines until APTT is therapeutic (46 to 70 seconds).

2. When 2 consecutive APTTs are therapeutic, order

APTT every

24 hours only (and adjust drip as needed).

3. Dosages of heparin when calculated by weight are

rounded off to nearest 100 U/h.

4. Order complete blood cell and platelet count every 3

days

during heparin therapy.

5. Stop heparin 4 hours before surgery. After surgery,

Management of patients on salicylic acid therapy

For uncomplicated forceps extraction of 1 to 3 teeth, there is usually no need to interfere with aspirin treatment.

In patients receiving up to 100 mg SA daily, bleeding during oral surgical procedures is controllable with suturing and direct packaging with gauze,31 resorbable gelatin sponge, oxidized cellulose, or microfibrillar collagen

Patients receiving higher doses, current value of bleeding time should be established, if >20 min surgery to be postponed or if emergency in consultation despmopressin acetate.

Patients on Aspirin with hemophilia or uremia

medical advice & to discontinue aspirin for 7

days before the procedure.

LITERATURE…

1. J.C.Souto et al (1996); JOMS, “Oral Surgery in

Anticoagulated Patients Without Reducing the

Dose of Oral Anticoagulant: A Prospective

Randomized Study” compared bleeding

complications in 6 perioperative schedules in 92

patients chronically treated with coumadins and

concluded that maintaining the oral

anticoagulant regimen and use local tranexamic

acid as an antifibrinolytic agent post-op for 2

days are safe, simple & less troublesome.

2. P.Devani et al (1998); BJOMS, “Dental

extractions in patients on warfarin:is alteration of

anticoagulant regime necessary?” studied a

controlled group of 32 and experimental group

of 33 patients on warfarin under local

anesthesia on an outpatient basis and proposed

that provided the INR is within the therapeutic

range of 2.0 to 4.0 and local measures are used

to control postoperative bleeding, there is no

justification in altering warfarin treatment prior to

dental extractions in these patients, and thereby

exposing them to the risk of thromboembolism.

3. G.Carter et al (2003); IJOMS, “Tranexamic acid

mouthwash— A prospective randomized study

of a 2-day regimen vs 5-day regimen to prevent

postoperative bleeding in anticoagulated

patients requiring dental extractions,” conducted

a prospective randomized study analysing the

use of 4.8% tranexamic acid post-op mouthwash

over 2 days vs 5 days to prevent bleeding. 85

patients (21-86 years). Gp-A for 2 days Gp-B for

5 days by same surgeon on ambulatory basis,

assessed 1,3 & 7th day for bleeding and

proposed that 2day course was equally effective.

4. K.Webster et al (2000); BJOMFS, “Management of anticoagulation in patients with prosthetic heart valves undergoing oral & maxillofacial operations” gives guidelines for minor surgical procedures as-the anticoagulation regimen does not require alteration if INR <4.0, if INR >4.0 warfarin should be discontinued & surgery to be done when INR is therapeutic range. Use of LA with vasoconstrictor and local hemostatic methods is recommended, & operative field should be irrigated with 4.8% tranexamic acid. Sockets and mucoperiosteal flaps should then be sutured & oxidized cellulose gauze(Surgicel) placed in socket.

Oral rinsing 4.8% TA sol 10ml for 2 min qid for 7 days

For Major surgery(parotidectomy or

neck dissection)

Discontinue warfarin on 3 evenings before addmission, & admitted on day before surgery.

Inj. LMWH in prophylactic dose if INR<2.0

On day of surgery INR checked to ensure the PT is within normal limits(INR <1.3) & prophylactic dose of LMWH 2 hr pre-op given

If INR =not normal range vit-K 1mg i.v. which brings INR in accepted range in 2-3 hrs.

Warfarin is started at night of surgery at a double dose . INR should be checked daily & dose adjusted.

Emergency surgery… If can be postponed for few hours-oral

anticoagulation can be partially reversed by vit-

k 1mg i.v.

If immediate surgery is required, fresh frozen

plasma or prothrombin complex conc should be

given to correct anticoagulation & hematologist’s

advice is invaluable.

SUMMARY & CONCLUSION..

Surgery is the main oral healthcare hazard to the

patient with a bleeding tendency, which is mostly

caused by the use of anticoagulants The

traditional management entails the interruption of

anticoagulant therapy for dental surgery to

prevent hemorrhage. However, this practice may

increase the risk of a potentially life-threatening

thromboembolism.

The management of oral surgery procedures on

patients treated with anticoagulants should be

influenced by several factors:

extent and urgency of surgery,

laboratory values,

treating physician’s recommendation,

available facilities,

dentist expertise, and

patient’s oral, medical, and general condition.

References..

Medical Problems in Dentistry-Cawson & scully

K.D. Tripathi-Pharmacology

Reference Articles

Clinics of North America

IJOMS

JOMS

BJOMS

OOOR

Thankyou..