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Dr. Nitish parmar University College of Medical Sciences & GTB Hospital, Delhi.

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Presentation on theme: "Dr. Nitish parmar University College of Medical Sciences & GTB Hospital, Delhi."— Presentation transcript:

1 Dr. Nitish parmar University College of Medical Sciences & GTB Hospital, Delhi

2 Definition Etiology Pathophysiology Preoperative evaluation Anaesthetic management AS/AR

3 esv edv

4

5 Wall tension = P x R / 2h P= pressure R = radius h= wall thickness Increase wall tension stimulates concentric hypertrophy of LV

6  Aortic stenosis refers to obstruction of flow at the level of the aortic valve  Restricted systolic opening of the valve, with a mean transvalvular pressure gradient of at least 10 mm Hg.  Normal aortic valve area is 2.5-3.5cm²  Haemodynamically significant obstruction occurs at valve area of < 1 cm 2

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8 Senile calcific degeneration Calcific changes of bicuspid valve Rheumatic disease ( most common in India)

9 Chronic pressure overload Peak systolic wall stress Parallel sarcomere replication Concentric hypertrophy ( no increase in the LV size )

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11 AORTIC STENOSIS LV outflow obst. ↑LV systolic P↑ LVET↑ LV diastolic P↓ AoP ↑ LV mass LV Dysfunction ↑ Myocardial O2 consumption ↓ Diastolic time Myocardial ischemia LV Failure

12  Increased diastolic stiffness magnifies the importance of atrial systole to ventricular filling  Hypertrophied ventricle is highly sensitive to ischemia  Increase myocardial oxygen demand  Decreased coronary perfusion gradient  Circulatory abnormalities in myocardium  Decreased capillary density  Abnormal thickening of coronary arterioles

13 dysopnea angina syncope

14 Angina ↓Supply ↑ LVEDP Hypotension Abnormal coronary circulation ↓capillary density Thickened arterioles ↑Demand  due ventricular hypertrophy Myocardial O2 mismatch

15 Systolic and diastolic dysfunction of left ventricle  pulm capillary hydrostatic pressure transudation of fluid into interstitial space  lung compliance  WOB dyspnea

16 Syncope fall in CO d/t arrythmia fixed CO state Other symptoms Symptoms of LVF occur only in the advanced stages of the disease When AS and MS coexist   volume produced by MS   gradient across the AV  masking of clinical findings by AS

17 Pulse: small volume, pulsus parvus et tardus BP – normal or low PP – low, due to fall in SBP when SV  in late stages

18 Cardiac apex – heaving S1 – normal / soft S2 – paradoxical split in late stages Palpable S4 Aortic ejection click Ejection mid systolic murmur

19 LVH LV- strain pattern

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21 MildModerateSevere Mean transvalvular pressure gradient (mmhg) <2525-40>40 Aortic valve area ( cm²) >1.51-1.5<1 Aortic jet velocity (m/sec) <33-4>4 However when cardiac output is low severe stenosis may be present with lower transvalvular pressure gardient and lower jet velocity Asessment of severity

22 Non cardiac surgery elective emergency Proceed with medical optimization and high risk severeMild to moderate GA/spinal /epidural

23 SEVERE symptomatic asymptomatic Risk of surgery Low/mod Proceed High Risk for AVR High Low AVR Consider valvuloplasty High risk stratification Risk for AVR HighLow Consider valvuloplasty High risk stratification

24 PreloadHigh ventricular filling pressure may be necessary to ensure adequate ventricular volume Adequate fluids and close monitoring AfterloadElevated but fixed. Maintain BP for adequate coronary perfusion Treat dec BP by 23-50 µg phenyl ephrine contractilityUsually not a problem- HRB/w 60-80Tachycardia managed by short acting b-blokers RhythmMaintain sinus rythmTreat AF with synchronized cardioversion. IschemiaIschemia is an ever present risk. Avoid inc. in HR & dec. in BP ECG monitor, aggressive t/t

25  Standard non-invasive ◦ ECG : 5 lead including lead II & V5 ◦ HR ◦ NIBP ◦ Pulse-oxymetry ◦ Capnograph ◦ Temperature ◦ Apply defibrillator pads beforehand

26 ◦ Invasive monitoring  IBP  CVP/PAC ??  Echocardiography (TEE)

27 Aim  To decrease anxiety & any associated likelihood of adverse circulatory responses produced by tachycardia ClassDrugDose (mg/kg)Route BZD Diazepam0.1-0.15PO, IM Midazolam0.03-0.07IM OpioidsMorphine0.2IM

28 ASMild/mod Non opiod induction Regional anaesthesia Severe AS Opioid induction and maintainance

29 DrugInduction / intubationMaintenance Morphine1-3 mg/kg15-20µg/min Fentanyl20-40 µg/kg0.1-1.0 µg/kg/min Sufentanil2-20 µg/kg1.0-2.0 µg/kg/hr Alfentanyl80-200 µg/kg120-200 µg/min remifentanyl1-2µg/kg/min

30 Analgesia Induction Muscle relaxant Opioid (Morphine @0.1mg/kg, fentanyl) Prevents tachycardia All IV agents (etomidate @ 0.3- 0.5mg/kg) HR stableAvoid ketamine Cardiostable like vecuronium HR stable, Pancuroniun offset bradycardia d/t opioid Avoid histamine releasing drug

31 Maintenance N2O + Narcotics or volatile agents (low conc) Adequate plane of anesthesia HR, SVR, PVR, Myocardial contractility maintained Avoid tachycardia Iso/ sevo/des Reversal Slow NMB/anesthesia reversal Avoid tachycardiaPrefer glycopyrrolate over atropine IV Fluid RL/NS/blood products CVP guidedExcessive: PE

32 Non-opioid induction agents ThiopentonePropofolEtomidateKetamineBZP MAP  HR  CO  SVR 

33 PanVecRocAtraMivSch MAP  -  HR  -  CO  -  - SVR---  - Histamine---++-

34 N2ON2OHaloIsoSevoDes BPN/C   HRN/C  N/C or  SVRN/C  CON/C   N/C or  PVR 

35 Majority of the cardiac events in non cardiac surgery occur in postoperative period Monitoring Oxygen Pain relief: multimodal including neuroaxial opioids Intravenous fluids

36  Technique should be applied cautiously  Mild to moderate aortic stenosis: can be used  Severe : contraindicated  Epidural anesthesia is preferable to spinal anesthesia  Spinal with opioid  Caution with anticoagulants

37  Mechanical ◦ Greater durability ◦ Needs life long anticoagulation ◦ More complications ◦ Preferred in younger patients (<65)  Bioprosthetic ◦ Less durable ◦ No need for anticoagulation ◦ Lesser complications ◦ Preferred in older patients who donot need anticoagulation Prosthetic valves

38  Valve thrombosis  Systemic embolization  Structural failure  Hemolysis  Paravalvular leak  Endocarditis

39  Dental procedures  Procedures involving incision of respiratory mucosa (adenoidectomy, tonsillectomy)  Incision on infected skin, musculoskeletal tissue  Cystoscopy if results of urine culture not known

40 POAmoxicillin 2g Allergic PO Cephalexin 2g OR Clinda 600mg OR Azithro 500mg **Don’t use Cephalexin if anaphylaxis, angioedema, or urticaria w/penicillins or ampicillin IVAmpicillin 2gm IV/IM OR Cefazolin 1g IV/IM OR Ceftriaxone 1g IV/IM IV allergic Cefazolin 1g IV/IM OR Ceftriaxone 1g IV/IM OR Clinda 600mg IV/IM

41 Discontinue warfarin at least 5 day before Sx Bridge with SC LMWH or IV unfractionated heparin (36 hrs later) Asses INR 1-2 days before Sx If >1.5 1-2 mg oral vit K

42 Patient receiving SC LMWH-stop 24 hrs prior Patient receiving UF heparin-stop 4 hrs prior Post operative Emergent procedure: treat with 2.5-5.0 mg IV vitamin K For faster reversal: FFP Minor Sx Major Sx Begin after 24 hrs Begin after 48-72 hrs

43 Start the patient back on oral warfarin Monitor PTT and aPTT on daily basis Attain INR of 2.5-3.0 for 2-3 days Stop heparin and continue warfarin

44  Neuraxial block should be delayed for 12 hrs (prophylactic) and 24 hrs (therapeutic) after last dose of LMWH  Removal of epidural catheter should take place 12 hrs after last dose  Subsequent dosing delayed for 2 hrs

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46  Echo ◦ Ejection fraction ◦ Normal functioning of valve ◦ Paravalvular leaks ◦ Vegetations ◦ Clots  In a patients with prosthetic valves rest of the anesthetic concerns are similar to a regular non VHD patient

47 incompetence of the aortic valve, in which a portion of the left ventricular forward stroke volume returns to the chamber during diastole.

48 Acute IE Trauma Aortic dissection Chronic Abnormalities of AV (congenital bicuspid valve) Aortic root – syphilis, cystic medial necrosis Marfan’s syndrome Rheumatic arthritis In approximately two third of the patients with valvular AR, the disease is rheumatic in origin

49 Volume overload acutechronic LV cannot dilate sufficiently  Effective SV   Sudden  in LVEDP  Transmitted to pulm circ.  Acute pulm congestion

50 Chronic overload ↑LVEDV ↓ Series replication of sarcomere ↓ Chamber enlargement ↓ Eccentric hypertrophy ↑ wall stress ↓ Concentric hypertrophy cardiomegaly (mild)

51 compensatory measures fail ↑ LVEDV and ↑ LVEDP forward SV decline development of symptoms

52 VOLUME PRESSURE ACUTE CHRONIC

53 Symptoms Exertional dyspnoea Palpitations Orthopnoea PND

54  Water hammer pulse  Quinke’s pulse  Traube’s sign  Duroriez sign  Widened pulse pressure

55 Cardiac apex – shifted laterally and inferiorly,. S3 Systolic thrill S2 – single or narrowly split A2 – soft P2 obscured by the diastolic murmur Early diastolic murmur – aortic area Ejection systolic murmur of functional AS Austin flint murmur mid diastolic murmur in mitral area.

56 Cardiomegaly Enlarged aorta Later signs of CHF may be present

57  Semiquantitative assesment GradeRJA/LVOTARJH/LVOTH Mild<4%<25% Moderate4%-24%25%-46% Moderately severe25-59%47%-65% Severe>59%>65% RJA -regurgitant jet area RJH -regurgitant jet height LVOTA -LV outflow tract area LVOTH -LV outflow tract height

58  Quantitative assessment GradeRegurgitant fraction Mild<20% Moderate20%-39% Moderately severe40%-60% Severe>60% Regurgitant fraction = (TSV-FSV)/TSV TSV= total stroke volume FSV = forward stroke volume

59  Signs of LV dysfunction  LVEF < 50%  EDD > 70mm  ESD > 55mm

60 Non cardiac surgery elective emergency Proceed with medical optimization and high risk symptomatic Postpone the case and refer for valve replacement Asymptomatic with LV dysfunction Mild to moderate GA/spinal /epidural Postpone the case and refer for valve replacement

61  If the patient is already a known case of endocarditis. POAmoxicillin 2g Allergic PO Cephalexin 2g OR Clinda 600mg OR Azithro 500mg **Don’t use Cephalexin if anaphylaxis, angioedema, or urticaria w/penicillins or ampicillin IVAmpicillin 2gm IV/IM OR Cefazolin 1g IV/IM OR Ceftriaxone 1g IV/IM IV allergic Cefazolin 1g IV/IM OR Ceftriaxone 1g IV/IM OR Clinda 600mg IV/IM

62 PreloadNormal to slightly raisedAvoid over/underloading AfterloadReduction by anaesthetics or vasodilators beneficial to reduce regirgitant flow Avoid sudden increase in afterload during induction contractilityDepressed at a later stageInotropic support may be necessary HRModerate tachycardia (80- 100) Prevent bradycardia, will increase regurgitation Rhythm Rhythm is usually not a problem - IschemiaIschemic risk is present d/t low diastolic BP Hypotension should be avoided

63  Standard non-invasive ◦ ECG : 5 lead including lead V5 ◦ HR ◦ NIBP ◦ Pulse-oxymetry ◦ Capnograph ◦ Temperature

64 DrugInduction / intubationMaintenance Morphine1-3 mg/kg15-20µg/min Fentanyl20-40 µg/kg0.1-1.0 µg/kg/min Sufentanil2-20 µg/kg1.0-2.0 µg/kg/hr Alfentanyl80-200 µg/kg120-200 µg/min remifentanyl1-2µg/kg/min

65 Pre medication Analgesia Induction Muscle relaxant BZP,opioidsAvoid excessive sedation Opioid (Morphine @0.1-0.2mg/kg avoid bradycardia All IV agents (etomidate @ 0.3-0.5mg/kg) HR stablePrevent sudden ↑SVR, ↓ HR Cardio-stable like vecuronium HR stable, Pancuroniun offset bradycardia d/t opioid

66 Maintenance Volatile agents (Iso/sevo/des) ↑HR, ↓ SVR, minimal negative inotropic effects Reversal Slow NMB/anesthes ia reversal Prevent sudden HT IV Fluid RL/NS/colloids /blood products CVP guidedOveloading may exacerbate CHF

67  Better tolerated than AS patients  Mild to moderate aortic regurgitation: can be used  Severe : contraindicated  Epidural anesthesia is preferable to spinal anesthesia  Avoid hypotension and bradycardia  Caution with anticoagulants

68 Majority of the cardiac events in non cardiac surgery occur in postoperative period Monitoring. Oxygen. Pain relief. Intravenous fluids.

69  Combined stenotic and regurgitant lesions impose extra burden on heart  Risk criteria for both the lesions should be considered, however more severe lesion should be given priority  If both lesions of equal intensity, stenotic lesion should be given importance

70  Patients with valvular lesions can be managed without tremendous increase in morbidity and mortality with modern anaesthetic agents and techniques  Efforts should be made for early detection and assessment of the lesion severity  High degree of attention should be paid to preoperative optimization and risk stratification  Regardless of the anaesthetic technique used all anaesthetics should be carefully titrated  Hemodynamic goals should be defined preoperatively and should be aggressively defended

71  Kaplan’s Cardiac Anesthesia; 5 th edition  Miller’s Anesthesia; 7 th edition  Clinical Anesthesia; Barash, Cullen, Stoelting, 5 th edition  Stoelting’s Anesthesia & Co-existing Disease; 5 th edition  Harrison’s Internal Medicine; 17 th edition  Wylie & churchill- Davidson’s A Practice of Anesthesia; 7 th edition  Clinical Anesthesia; Morgan 4 th edition

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