ANAESTHETIC IMPLICATIONS AND MANAGEMENT OF PREGNANCY WITH RHD(MS, MR)

1. ANAESTHETIC IMPLICATIONS AND MANAGEMENT OFPREGNANCY WITH RHD(MS, MR) Presenter : Dr. Vineeta venkateswar Moderator : Dr. Deepti University College of Medical Sciences & GTB Hospital, Delhi www.anaesthesia.co.in

2. CARDIOVASCULAR CHANGES DURING NORMAL PREGNANCY CARDIAC OUTPUT: • ↑ from 5th wk, peak (40-50%) at 30-34 wks • ↑ further during labour (50%) & immediate postpartum (70%) • Pre-labour values 1 hr after delivery & pre-pregnancy values by 4wks BLOOD PRESSURE • SVR ↓ by 20% • ↓ in diastolic BP and MAP by 5-10 mmHg

3. HEART RATE • ↑ by 20% HAEMATOLOGICAL CHANGES • Blood volume ↑ by 40-50%. Maximum at 30-32 wks. • Hemoglobin mass ↑ by 20-30% • Plasma volume ↑ 40-50%. Overall effect – hemodilution, fall in Hb. • Hypercoagulable state- Increase in fibrinogen, clotting factors.

4. CLINICAL FINDINGS • Apex beat : 4th ICS, lateral to mid-clavicular line. • Heart sounds: S1 - loud, split. S3 may be heard • Murmur: systolic murmur in apical or pulmonary area, continuous mammary murmur. CHEST X RAY • Avoided • Heart displaced upwards & rotated on its axis • Straightening of upper left cardiac border

5. ECG: • Reflects the altered heart position • LAD of 15 degree • QRS complex - low voltage • Atrial and ventricular extrasystoles

6. MITRAL STENOSIS

7. EPIDEMIOLOGY • Heart disease in pregnancy : 0.3 – 3.5% • Incidence of RHD ↓, esp in developed countries and some urban areas • Most common cardiac lesion in India - rheumatic origin, followed by congenital ones • Maternal mortality in RHD - <1% in asymptomatic patients to 17% in complicated cases RHEUMATIC HEART DISEASE - cardiac involvement of an auto immune reaction, myocardial protein laminin imunologically similar to cell membrane proteins of beta-hemolytic streptococci and becomes target of auto antibodies

8. MITRAL STENOSIS : Decrease in Mitral valve orifice area leading to chronic & fixed mechanical obstruction to LV filling • RF first occurs at 6-15 yrs • MS after about 5 yrs • First symptoms after another about 15yrs • Average age of onset of symptoms – 31 yrs • Pulmonary congestion, pulmonary hypertension, RVF after another 5-10 yrs

9. Over several decades MS evolves by: • Thickening of the leaflets • Fusion of the commisures • Fusion or shortening of the chordae (“fish-mouth” or “button-hole” valve) • Calcification of valve • Thrombus due to venous stasis in LA

10. MITRAL STENOSIS:PATHOPHYSIOLOGY

11. Mechanical obstruction to left ventricular diastolic filling Adaptative↑ in LAP to maintain LV filling ------------------------------------------------------------------------- LA enlargement ↑ in pulmonary venous pressure → ↑ in pulmonary arterial pressure Atrial fibrillationTransudation of fluid into pulmonary interstitial space Thrombus formation Systemic thrombo-embolism ↓ed pulmonary compliance ↑Work of breathing Progressive dyspnoea on exertion/rest Chest pain, palpitations, fainting Pregnancy, Pain, sepsis (↑ HR/CO) Acute ↑ in LAP Pulmonary edema ↑ in pulmonary arterial pressure Pulmonary arterial hypertrophy (Pulmonary HTN) RV hypertrophy and dilatation RV failure Peripheral edema , neck vein distension, hepatomegaly

13. PREGNANCY WITH MS EFFECT OF PREGNANCY ON MS • Worsening of NYHA functional status by 1-2 grades. Presentation of anatomically moderate stenosis become functionally severe. • ↑ incidence of pulmonary congestion (25%), AF(7%), paroxysmal atrial tachycardia(3%), other complications like RVF, embolism, IE

14. New York Heart Association(NYHA)Functional Classification of Heart Failure • NYHA 1: Known cardiac disease with no limitation of physical activity and no objective evidence of cardiovascular disease • NYHA 2: Slight limitation of normal physical activity and objective evidence of minimal disease • NYHA 3: Marked limitation of physical activity and objective evidence of moderate disease • NYHA 4: Severe limitation of activity including symptoms at rest and objective evidence of severe disease

15. Women who were asymptomatic before pregnancy usually tolerate pregnancy well but not with severe MS Physiological basis: • ↑ HR of pregnancy limits time available for filling of left ventricle → results in increased LA and PA pressures → risk of pulm edema • ↑ blood volume → additional load • fixed cardiac output state → CO cannot ↑ to compensate for ↓ SVR

16. Risk of maternal death greatest after 30 wks , esp during labour and immediate post partum Physiological basis: • CO and blood volume peak at this time • Tachycardia during labour- along with further ↑ peripheral demand • Sudden ↑ in preload immediately after delivery floods the central circulation→ severe pulm edema

17. EFFECT OF MS ON PREGNANCY • High-risk pregnancy • Increased risk of complications, mortality • Close monitoring, repeated visits required EFFECT OF MS IN PREGNANCY ON FETUS • Cardiac output cannot be ↑, fetal circulation compromised • IUGR, LBW babies • Preterm labour

18. HISTORY AND EVALUATION • 25% women with MS : 1st symptoms during pregnancy • H/o rheumatic fever in childhood • Fatigue, progressive shortness of breath. • Cough, hemoptysis • Chest pain, palpitations • Right sided failure (neck vein distension, peripheral edema) • Left sided failure (orthopnea, PND) • Worsening of sypmtoms in prior pregnancies • If known case – may be on digoxin/diuretics/ betablockers/ IE prophylaxis

19. TREATMENT HISTORY DIGOXIN: • Narrow therapeutic range – 0.5 to 2 ng/ml • Life- threatening arrhythmias • Hypokalemia,Hypercalcemia and hypomagnesemia precipitate • Co-administration with beta blockers, or calcium channel blockers can cause serious bradycardia. BETA BLOCKERS: • Labetalol, propanolol , esmolol • Co- administration with digoxin: serious bradycardia DIURETICS: • Electrolyte disturbances • Can precipitate digoxin toxicity

20. EXAMINATION GENERAL FEATURES • Depends on severity • Low volume pulse • Peripheral edema, JVP raised • Mitral facies: Pink purple patches on the cheeks, cyanotic skin changes from low cardiac output SYSTEMIC EXAMINATION Respiratory: Basal crepts in pulmonary edema Abdomen : Tender hepatomegaly Ascites (advanced)

21. CARDIAC SYSTEM: • S1 loud • S2: closely split or fixed, P2 accentutated • opening snap at base of heart along left sternal border (mitral area), absent in later stages, narrow OS-S2 gap indicates severity. • Middiastolic rumbling murmur with presystolic accentuation; best heard at the apex in lateral recumbent position, severity related to duration.

23. INVESTIGATIONS • Routine investigations: complete hemogram serum electrolytes: Serum K, Ca, Mg levels • Serum digoxin levels • Coagulation profile • ECG • 2D /Doppler ECHO

24. ECG P mitrale (LAH): broad notched P wave, large, bifid appearance in II, III ,aVF RVH, RAD

25. Chest X-ray (usually not done in pregnant patients) • normal to ↑ed cardiac shadow • straightening of the left heart border and elevation of left main bronchus (left atrial enlargement) • mitral calcification • evidence of pulmonary edema/ HTN

26. 2D /Doppler Echocardiography (non –radiological investigation-preferred in pregnant patients) • anatomy/size of mitral valve & its appendages • severity of MS (area of orifice) • size & function of ventricles • thrombus • transvalvular pressure gradient , PA pressure (Doppler) • Cardiac catheterization & invasive measurement • almost never necessary • reserved for situations ECHO sub-optimal/conflict with clinical presentation

27. CLASSIFICATION ACC AHA Guidelines 2006

28. If severe, patient referred to a cardiac centre for mitral valve surgery to enable her to complete pregnancy Mitral Valvotomy (preferred): palliative , buys time for woman to complete pregnancy. Mitral Balloon Valvuloplasty : safe & effective if valve pliable, avoids open heart surgery Mitral Commissurotomy may be required at any stage of gestation.

29. GOALS OF MANAGEMENT • Maintain a slow heart rate, tachycardia to be strictly avoided • Maintain sinus rhythm - AF to be aggressively treated • Optimize venous return and PCWP to maximize LVEDV- avoid aortocaval compression & blood loss • Avoid ↑ SVR- maintain adequate SVR • Avoid ↑ PVR- prevent pain , hypoxemia, hypercarbia and acidosis

30. ROLE OF ANAESTHESIOLOGIST • During pregnancy * Sudden decompensation – intensive care -AF -CHF * Non-obstetric surgery • Normal vaginal delivery • Caesarean section

31. ATRIAL FIBRILLATION

33. Digoxin 0.25 to 0.5 mg IV, then 0.25 mg IV 4 to 6 hrly to maximum of 1 mg • Propanolol 1 mg IV over 2 minutes, may repeat every 5 min to maximum of 5 mg, maintenance 1 to 3 mg IV 4 hrly • Calcium channel blocker Diltiazem 15 to 20 mg IV over 2 min, may repeat in 15 min, maintenance 5 to 15 mg per hr by continuous IV infusion Verapamil 5 to 10 mg IV over 2 min, may repeat in 30 min

34. ANTI COAGULANTS Anticoagulation indicated if * History of embolic phenomena or * Chronic AF • Heparin during first & last trimester of pregnancy, Unfractionated heparin s.c. 10 000 to 20000 units every 12 hr – aPTT 1.5 x control • LMW Heparin may be considered despite the limited data available • Warfarin - considered during the second trimester for pregnant patients with AF at high thromboembolic risk.

35. If a patient on Anticoagulant requires surgery… Warfarin • Elective -discontinue at least 5 days before elective procedure, assess INR 1 to 2 days before surgery, if >1.5, consider 1-2 mg of oral vitamin K • Emergency- consider 2.5-5 mg of i.v.vitamin K, consider FFP • Patients at high risk for thromboembolism: bridge with therapeutic s.c. LMWH (preferred) or i.v.UFH Heparin • LMWH : last dose 24 hrs before surgery • Heparin discontinued 4 hrs before surgery American Society of Regional Anesthesia (ASRA) Guidelines 2010

36. ROLE OF ANAESTHESIOLOGIST • During pregnancy * Sudden decompensation -AF -CHF * Non-obstetric surgery • Normal vaginal delivery • Caesarean section

37. CHF Similar as in non-pregnant pts • General : • Bed rest • Salt & fluid restriction • Supplemental oxygen • Diuretics: • Loop diuretics , eg. furosemide 20-80 mg 1-2 times/day • Thiazides & K-sparing to be avoided • Beta-blockers: • Metoprolol (6.25- 75 mg 12hrly), bisoprolol, carvedidol • Digoxin (0.125- 0.5 mg/d) Consider termination of pregnancy

38. IE PROPHYLAXIS Pregnancy carries no additional risk for bacterial endocarditis. Routine antibiotic prophylaxis in patients with valvular heart disease undergoing uncomplicated vaginal delivery or caesarean section no longer recommeded(unless infection suspected). Antibiotic prophylaxis as practiced for the prevention of wound sepsis is more than adequate. Indications for antibiotic prophylaxis : • Patients with prosthetic heart valves, • Previous history of endocarditis, • Complex congenital heart disease The Committee on Rheumatic Fever, Endocarditis and Kawasaki Disease (American Heart Association), Circulation.2008; 118: 2395-2451 ACC/AHA 2008 Guidelines

39. Non –penicillin allergic patient Intravenous Ampicillin 2 g plus gentamicin 1.5 mg/kg IV or IM 30 min before procedure, followed by ampicillin 1 g IV or IM, or amoxicillin 1 g orally, 6 hours after initial dose. Penicillin allergic patient Vancomycin 1 g IV once; plus gentamicin as above within 30 min of the start of the procedure

40. ROLE OF ANAESTHESIOLOGIST • During pregnancy * Sudden decompensation -AF -CHF * Non-obstetric surgery • Normal vaginal delivery • Caesarean section

41. NORMAL VAGINAL DELIVERY Invasive hemodynamic monitoring ( CVP. IBP, PA catheters) • Severe MS • NYHA III or IV • Sudden cardiovascular collapse • Persistent oliguria despite adequate fluid PA catheter: Trends signify changes in LA pressure Maintain around 15 mmHg

42. First stage of labour: • Restricted fluid intake- conc. solutions of drugs, diuretics • Left uterine displacement; oxygen; fetal monitoring • Adequte analgesia to prevent tachycardia-lumbar epidural catheterization recommended • Epidural analgesia: low dose bupivacaine(0.125%-0.0625%) + fentanyl- 2 mcg/ml or sufentanil 0.2-0.3 mcg/ml • CSE use also recommended Intrathecal- fentanyl 15-25 mcg or sufentanil 1.5-5 mcg Epidural- slow low-dose bupivacaine + opioid • Opioids infusions, PCIA

43. Epidural Test Dose • Traditional – Lignocaine with 15-20 mcg Adr • Role is controversial • Alternatives • Adr replaced with fentanyl 50-200 mcg; observe for dizziness, drowsiness after 5 min • Air (1 ml) ; Doppler over precordium Guay et al; The Epidural Test Dose: A Review; Anesth Analg 2006;102:921–9

44. Second stage of labour: • Maternal pushing efforts result in a Valsalva maneuver- sudden undesirable ↑ in venous return. • Maintain adequate analgesia; Perineal analgesia ( paracervical / pudendal nerve block.) ; epidural extended • Mother discouraged from bearing down or pushing • Obstetrician cuts short second stage - vacuum extraction or outlet forceps

45. Hypotension prevented by judicious use of fluids and continuous left uterine displacement • If hypotension occurs: Vasopressor of choice- Phenylephrine 100-500 mcg increments IV bolus; followed by 100-180 mcg/min constant infusion Metarminol also used i.v. infusion of 15-100 mg in 500 ml of 5% dextrose or NS) • Prophylactic ephedrine and rapid overenthusiastic fluid therapy to be avoided • Post partum: careful monitoring

46. ROLE OF ANAESTHESIOLOGIST • During pregnancy * Sudden decompensation -AF -CHF * Non-obstetric surgery • Normal vaginal delivery • Cesarean section

47. CAESAREAN SECTION REGIONAL ANAESTHESIA (preferred in mild to moderate stenosis)- • Lumbar epidural anaesthesia preferred- produces slower, more controllable hemodynamic changes, anesthetic level established slowly by titrating drug with the degree of anaesthesia. • Epidural catheter, if inserted during labour, can be extended • CSE may be used -5mg hyperbaric .5% bupivacaine with 25mcg fentanyl, 3ml 2% lignocaine Update In Anesthesia :Issue 19 (2005) Article 9: Anaesthesia For The Pregnant Patient With Acquired Valvular Heart Disease; Joubert IA, Dyer RA, 

48. Role of SAB: • Avoided due to precipitous fall in BP • Small-dose spinal anaesthesia (e.g.1mL 0.25% bupivacaine with 10-20mcg fentanyl or 0.1-0.2mg morphine) may be used as an alternative to epidural anaesthesia (may be inadequate for Cesaerean Section, adequate for short-duration labour analgesia) Update In Anesthesia :Issue 19 (2005) Article 9: Anaesthesia For The Pregnant Patient With Acquired Valvular Heart Disease; Joubert IA, Dyer RA, 

49. General Anaesthesia Indications: • NYHA functional class III or IV • obstetric indications • Pt on anticoagulants Mild stenosis(NYHA grade I/II) • intravenous thiopentone/ etomidate for induction • Rocuronium/scholine for tracheal intubation • quick and gentle laryngoscopy • tachycardia following tracheal intubation or surgical incision avoided - β blockers

50. Moderate or severe stenosis (NYHA III/IV) • slow induction with inhalational agents like sevoflurane and IV fentanyl suggested • Opioids- sufentanil, remi • avoid nitrous oxide (in pulm HTN) • avoid hypoxia, hypercarbia acidosis and pain to prevent ↑PVR • reversal- slow, with use of esmolol if required • invasive monitoring