risk factors , categories , thromboprophylaxis in gynaecology , dosage for prevention , risk assessment , various recommendations , drugs for thromboprophylaxis

1. VENOUS
THROMBOEMBOLIS
M
-RECENT RECOMMENDATIONS
-Dr.G.Abirami

2. VTE in GYNAECOLOGY
Oestrogen and VTE risk
 Oestrogen use - dose dependant, route of
administration.
 Risk is lower with transdermal, intra-uterine
hormonal therapy and progesterone-only oral
contraceptive.
Gynaecological surgery and VTE :
prevalance – 15 to 30% , fatal PE 0.2 to 0.9%
- Patient related
- Surgical procedure related

3. PATIENT RELATED RISK
FACTOR :
 age >60 years
 prior history and family history of VTE
 immobility
 dehydration
 Sepsis
 underlying malignancy
 pregnancy
 oestrogen therapy
 obesity
 hereditary thrombophilia
 inflammatory bowel disease,
 human immunodeficiency virus infection and
 autoimmune diseases including antiphospholipid
syndrome.

4. SURGICAL PROCEDURE
RELATED RISK FACTOR:
 Duration of the procedure
 Degree of tissue damage
 Degree of immobility following surgery
 Nature of the surgical procedure

5. RISK CATEGORIES FOR
GYNAECOLOGICAL SURGICAL PATIENTS :
VERY HIGH RISK :Major surgery , age >60 years with malignancy or
history of VTE or both
HIGH RISK
-Major surgery , 40 to 60 years with malignancy
-Major surgery with additional risk factors – obesity , hereditary
thrombophilia, HIV ,auto immune disease, oestrogen therapy
 MODERATE RISK
-major surgery for benign condition without other risk factor
-minor or laproscopic surgery with additional risk factors such as obesity ,
hereditary thrombophilia, HIV ,auto immune disease, oestrogen therapy
 LOW RISK
Minor (< 30 min ) or non complex laproscopic surgery without other risk
factors

6. THROMBOPROPHYLAXIS :
 LOW RISK: EARLY FREQUENT AMBULATION
 MODERATE RISK : LMWH OR LOW DOSE UFH,
- 5000 UNITS TWICE DAILY, OR IPC OR GCS
 HIGH RISK: LMWH OR LOW DOSE UFH,
- 5000 UNITS THRICE DAILY, OR IPC.
- ALTERNATE CONSIDERATIONS INCLUDE A
COMBINATION OR LOW DOSE UFH OR LMWH PLUS
MECHANICAL PROPHYLAXIS WITH GCS OR IPC
 VERY HIGH: 5000 UNITS THRICE DAILY, OR IPC OR GCP.
CONSIDER CONTINUING LMWH PROPHYLAXIS FOR
UPTO 4 WEEKS AFTER DISCHARGE.

7. DOSAGE OF BRIDGING ANTICOAGULATION
IN VTE PREVENTION IN GYNAECOLOGICAL
PATIENTS
ESTIMATED RISK FOR
THROMBOEMBOLISM
BRIDGING ANTICOAGULATION
HIGH HIGH DOSE (THERAPEUTIC DOSE)
•ENOXAPRIN 1MG/KG BID OR 1.5 MG/KG QD
•DALTEPRIN 100 IU/KG BID OR 200 IU/KG QD
•IV UFH TO ATTAIN APTT 1.5 TO 2 TIMES THE
CONTROL APTT
MODERATE “INTERMEDIATE DOSE”
EG- ENOXAPRIN 40MG BID
LOW “LOW DOSE” (PROPHYLACTIC DOSE)
•ENOXAPRIN 30 MG BID OR 40MG QID
•DALTEPRIN 5000 IU BID
•UFH 5000-7500 IU BID

8.  It is recommended to use weight-adjusted LMWH dosing
in patients at extremes of weight.
 It is recommended to start LMWH 6 - 12 hours after
surgery, provided there is no active bleeding.
 In patients at high risk of bleeding or undergoing
neuraxial anaesthesia, it is recommended to start LMWH
a minimum of 12 hours postoperatively.
 LMWH prophylaxis should be continued until the patient
is fully mobile.

9.  For major cancer surgery, 5 weeks of thromboprophylaxis is
recommended.
 For major surgery, in patients with additional risk factors, at
least 7 - 10 days of thromboprophylaxis is indicated.
 Avoid additional antiplatelet drugs for analgesia during
anticoagulation.
 In patients at high risk of bleeding, use of mechanical
prophylaxis such as intermittent pneumatic compression (IPC)
should be considered. There is, however, limited evidence for
graduated compression stockings.

10. VTE IN OBSTETRICS
 Pregnancy increases VTE risk by 4 to 5 times
 Absolute incidence of VTE in pregnancy –
0.025 to 0.1 %
 Greatest in the puerperal period
 Left side more common – compression of left
iliac vein by right iliac artery ( May Thurner
syndrome)
 More than half of DVT occurs in ileofemoral
veins

12. READINESS
 All patients should be assessed for VTE risk
multiple times in pregnancy, including during:
-Presentation for prenatal care
-Hospitalization for antepartum indication
-Delivery hospitalization (in-house postpartum)
-Discharge from a delivery hospitalization

13. RECOGNITION
 VTE risk assessment tools should be applied to every
patient
 Risk assessment tools are based on recommendations from
major society guidelines:
-American College of Obstetricians and Gynecology
(ACOG)
-American College of Chest Physicians (ACCP)
-Royal College of Obstetricians and Gynaecologists
(RCOG)
 Pharmacologic prophylaxis may be with unfractionated
heparin (UFH) or low-molecular weight heparin (LMWH)

14. RECOGNITION: FIRST PRENATAL
VISIT

15. RISK ASSESSMENT

16.  Antithrombin 3 deficiency – life time risk of
thrombosis 70 to 90%
 Protein C and protein S deficiency – 30 % life
time risk for thromboembolic event
 Factor v leiden mutation – 7 to 40% chance of
DVT
 Prothrombin gene mutation – 4 fold increased
risk
 Hyperhomocystinaemia – increased risk for
arterial thrombosis.

17. IN PATIENT ANTEPARTUM
HOSPITILIZATION

18. VAGINAL DELIVERY

19. CAESAREAN DELIVERY

20. CHEST RECOMMENDATION

21. RISK FACTORS FOR VTE ( RCOG)

23. RCOG SCORING SYSTEM

24. RCOG RISK ASSESSMENT
 If total score ≥ 4 antenatally, consider thromboprophylaxis
from the first trimester.
 If total score 3 antenatally, consider thromboprophylaxis
from 28 weeks.
 If total score ≥ 2 postnatally, consider thromboprophylaxis
for at least 10 days.
 If admitted to hospital antenatally consider
thromboprophylaxis.
 If prolonged admission (≥ 3 days) or readmission to hospital
within the puerperium consider thromboprophylaxis.

27. POST PARTUM

28. PROTOCOLS FOR PROPHYLAXIS

29. PROTOCOLS FOR THERAPEUTIC
DOSING

30. TIMING OF NEUROAXIAL ANESTHESIA

31. POST CAESAREAN
 VTE after LSCS is twice compared to vaginal
delivery
 Incidence of DVT after LSCS is 0.424/1000
and after vaginal delivery is 0.173/1000
 Emergency LSCS has double risk compared
to elective LSCS
 Women with additional risk factors
undergoing LSCS – graduated compression
stockings , pharmacological prophylaxis ,
intermittent pneumatic compression.
 If risk factors persist even after delivery ,
extended prophylaxis is advised.

32. DRUGS FOR THROMBOPROPHYLAXIS
 Unfractionated Heparin:
- Inactivates factor IIa and Xa and affects aptt, a measure of
thrombin activity
- Monitored by aptt – 2 to 2.5 INR
- Once desirable INR reached , repeat aptt every 2 to 3 days from
day 4 to 14 or until heparin is stopped.
- Complications of heparin – bleeding,necrosis of skin ,
thrombocytopeni, osteopenia and osteoporosis.
- HEPARIN INDUCED THROMBOCYTOPENIA :
 EARLY – occurs in first 48 hours, resolves in 5 days . Occurs due
to activation of platelet by heparin
 LATE – occurs 5 to 14 days , occurs due to activation of
antibodies against platelet factor 4 complex leading to bleeding
and paradoxical thrombosis.
 ANTIDOTE FOR HEPARIN IS PROTAMINE SULPHATE
-1 mg neutralises 100 units of heparin.

33. LMWH
- Dose calculation based on booking or most
recent weight (RCOG)
- Dose modification needed in obesity and
renal impairment
- Effectiveness measured by anti Xa
levels.target -0.3 to 0.5 antiXa units/ml
- Low – inadequate dosing , delayed specimen
draw, dose omitted, weight gain, gestation
- High- excessive dosing, weight loss, renal
dysfunction, reduced creatinine clearance

34.  CONTRA INDICATIONS :
- Active APH/PPH
- H/O stroke in last 4 weeks
- Thrombophilia (75,000) , hemophilia,VWD
- Uncontrolled hypertension(>200/120)
- Severe hepatic and renal disease
- CAUTION: LSCS / labour induction -stop UFH 12 hrs before ,
LMWH 24 hrs before and restart 4 to 6 hrs after vaginal
delivery , 6 to 12 hrs after LSCS

35. FONDAPARINUX :
- Selective Xa inhibitor
- Alternative in case of heparin intolerance or hypersensitivity
skin reaction to LMWH
- Dose – 7.5 mg for 50 to 100 kg , 5 mg for <50 kg , 10 mg for >
100 kg
- Avoid use in severe renal impairment
 WARFARIN – can be used in postpartum period safely
-warfarin embryopathy in first trimester 6% , 14 to 50% chance of
miscarriage , 30% anomaly risk , increased chance of bleeding
disorder and still birth.

36. THROMBOPROPHYLAXIS IN CARDIAC
PATIENTS
 New onset atrial fibrillation or flutter persisting
> 48 hrs require anticoagulation
 For long standing atrial fibrillation , if
electrical cardioversion is planned , start
anticoagulation 3 weeks prior and continue
for 4 weeks later.
 In patients with atrial fibrillation , risk of
thrombosis is very high – LMWH/UFH in first
trimester and after 36 weeks , in between
oral anticoagulant.

37. CONCLUSION