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..