case of prosthetic mitral valve for exploratory laparotomy

1. Dr N.G. Tirpude( HOD, dept of
Anesthesiology GMC Nagpur)
Dr. Bakshi (Asso. Poof)
Dr. V. Ankalwar(Asso. Prof)
Dr. Abhijeet Patil

2. A case of prosthetic mitral valve on
anticoagulants with chronic AF presents a great
preoperative, intraoperative and postoperative
challenge to an anesthetist due to risks
involved such as infective endocarditis,
thromboembolism, life threatening
arrhythmias and excessive bleeding .

3. A 43 yr women k/c/o RHD with MVR( ) done
in 2005 with chronic atrial fibrillation
Presented with c/o pain in abdomen since 2
months
Diagnosed with lump in abdomen posted for
exploratory laparotomy
She was on - T. warfarin 7.5 mg
(current INR 2.2)
T. Digoxin 0.25 mg
T. Verapamil 40 mg

4. Thin built , pale
Afebrile
PR- 74/min irregularly irregular with apex
pulse deficit 20-30 beats (HR>PR)
BP- 130/90 mmHg Rt UL supine
CVS- metallic click + at apex
RS, P/A, CNS- WNL

5. Hb 11 g/dl
INR 1.2
LFT, KFT, Sr electrolytes- WNL
ECG s/o atrial fibrillation with HR of 84/min.
2D ECHO s/o prosthetic valve in situ , LVEF
45% no atrial clot no vegetation
CT SCAN s/o well defined solid cystic lesion
in pouch of Douglas 8x4x5 cm

7. T. warfarin was discontinued 4 days prior to
surgery
Pt was shifted on sc unfractionated heparin
4000 IU QID
Heparin was discontinued 6 hrs before
surgery
T. verapamil and T.digoxin were continued
till the morning of surgery

8. On the day of surgery infective endocarditis
prophylaxis given
INR was 1.2
2FFP & 1 PCV kept ready
Defibrillator was kept ready
On OT table vitals -
- SpO2 - 99% on air
- HR on ECG 104/ min irregularly irregular
- BP - 130/90 mmhg

9. Epidural anesthesia was planned
Epidural catheter was secured in L3-L4 space
Intravascular placement of catheter was
excluded by absence of blood on aspiration
Bolus doge of 2% lignocaine 6cc with
bupivacaine 12 cc diluted to 20cc was given
with 0.3 ml sodabicarbonate.
After 20 min adequate level of anesthesia
was achieved up to T8-T10

10. Intraop vitals
- PR 90-115/min irregular
- SBP 90- 130 mmHg
- SpO2 99%
Sedation with fentanyl 25+25 mcg
3 mg Mephentermine was required only once
500 ml crystalloids were required intraop
Encapsulated hematoma of 8x4x5 cm was
removed from Pouch of Douglas
Surgery took around 90 mins

11. Epidural catheter was removed after giving
analgesic dose of 6cc 0.125% bupivacaine
with buprenorphine 100 mcg
Pt was shifted to recovery room for
observation
Post op period was uneventful
Since intraop hemostasis was satisfactory,
abdominal drains showed no excess bleeding,
we chose to restart heparin within 6 hours of
removal of epi.catheter and continued for 48
hours. And warfarin was started on next day.

12. Pts on mechanical prosthetic heart valve
needs proper anticoagulation as pt is
exposed to significant threat of TE and valve
dysfunction
Target INR is achieved with warfarin
Type of valve Target INR
New generation 2.5-3.5
Older types 3.5-4.5

13. Tricky situation for anesthesiologist
perioperatively
discontinuation of cont. OAC
OAC
Life threatening TE Significant
Bleeding
With AF risk is 1-20% risk high

14. -First, OAC can be continued during
procedures associated with low rates of bleeding.
- Second, OAC can be interrupted for several
days
prior to the procedure and resumed
immediately
following the procedure.
-Third, OAC can be interrupted with bridging
anticoagulation, using either heparin or low
molecular
weight heparin (LMWH)

16. High risk for
TE:bridging adviced
Intermediate risk of
TE : bridging on case
to case basis
Low risk for TE :
bridging not advised
- AF with
mechanical heart
valve in any
position
- Rheumatic AF
- Older mechanical
valve model
- Recently placed
mitral valve(< 3
month)
- AF with history of
cardiac embolism
- Venous or arterial
TE in last 1-3
month
- Cerebrovascular
disease with
multiple strokes or
TIA without risk
factors for cardiac
embolism
- Newer mechanical
valve models in
mitral position
- AF without history
of cardiac
embolism
- Venous TE >3-6
months
- AF without
multiple risks for
cardiac embolism
- Newer model
prosthetic valve in
aortic position
- intrinsic
cerebrovascular
disease without
stroke

17. As our pt was in high risk group we decided to
bridge the pt with unfractionated heparin(UFH)
according to ACCP guidelines which suggests
Discontinue OAC at least 3 days before major surgery.
Start SC conventional heparin or LMWH in
prophylactic doses.
Last dose before 3-6 hours preoperatively.
Restart heparin as soon as possible post operatively
(within 12 hour) and continue till 48 hours to enable
reduction in vitamin K dependent clotting factors
Start warfarin within 24 hrs post operatively

18. In case of emergency surgery , effect of
warfarin needs to be neutralized by FFP , the
dose of which depends on individual and
titrated till INR < 1.5.In addition, IV vitamin
K can be given in small doses.
In our case we could also achieve INR 1.2
which was safer to proceed for surgery with
regional anesthesia.

19. Patient was already in chronic AF.
Noxious stimulus can precipitate
- acute on chronic AF.
- ventricular arrhythmias.
- ventricular fibrillation.
Our strategy to reduce risks due to AF was
- control ventricular rate
- prevention of thromboembolism
- antiarrhythmic drugs and defibrillator was
kept ready
- tab.Verapamil & tab.Digoxin cont.till day of
surgery.

20. We decided to use epidural anesthesia in this pt
instead of GA
TO AVOID
- stress response associated with
laryngoscopy intubation and extubation ,
inadequate depth-life threatening
arrhythmias
- direct cardio depressant
effects of iv and inhalational
anesthetics
-hemodynamic instability
- respiratory complications

21. TO ACHIEVE :
- better analgesic profile
- hemodynamic stability
- better post op analgesia
-less intraop blood loss
-better hemostasis
-lesser cardiac and respiratory
complications

22. Use of LA with adrenaline for epidural test
dose should be avoided as it can cause
tachyarrhythmia, angina, ischemia,
hypertension which could have been fatal in
this case.

23. Key points to success
- Bridging with unfractionated heparin 4-5 days prior to surgery,
- INR maintained < 1.5 for proceeding with surgery ,
- to prevent possible bleeding problems and to administer neuraxial
block discontinuation heparin 6 h prior to surgery and restarted
within 6-12 h after surgery.
- Infective endocarditis prophylaxis should be given to all patients
with prosthetic heart valve.
- Antiarrhythmic drugs and defibrillator should be kept ready.
This case was managed successfully under epidural anesthesia
without any complications