Cardiac Anesthesia Update Charles E. Smith, MD Professor, CWRU School of Medicine Director, CT Anesthesia MetroHealth Medical Center

Objectives 1.ASE guidelines- IOTEE 2.ACC/AHA guidelines- Valves 3.Diabetes + hyperglycemia 4.Neurocognitive dysfunction 5.Transfusion

ASE/SCA Guidelines- TEE Accelerated growth of IOTEE by anesthesia Complexity of US technology Conduct of exam Interpretation of results Mathews JP et al: ASE / SCA Recommendations and Guidelines for CQI in Perioperative Echo. JASE + Anesth Analg 2006.

Training + Credentialing 2 levels of training: basic + advanced –Basic: within usual practice of anesthesia –ventricular fct, gross valve lesions –Advanced: full diagnostic potential of echo ASE /SCA/NBE: –Testamur status: exam –Board certified: 1 yr TEE/ CT fellowship [vs alternate training, 2-4 yr, 300 exams] Credentialing: hospital-specific process Mathews JP et al: JASE + Anesth Analg 2006.

Standard TEE Exam: Guidelines Comprehensive: 20 cross-sectional views –UE level: Asc aorta, MPA, L+R atria, AV+PV –ME level: L+R atria, L+R ventricles, MV+TV –TG: L+R ventricles –Thoracic Aorta: Desc + distal arch Mathews JP et al: ASE / SCA Recommendations and Guidelines for CQI in Perioperative Echo. JASE + Anesth Analg 2006.

Transgastric view: L+R ventricles

ME views: L+R atria, L+R ventricles, MV+TV

UE views: Asc aorta, MPA, L+R atria, AV+PV, pulm veins

Thoracic Aorta: prox asc aorta, distal arch, descending

ACC/AHA Guidelines Review of literature by experts Grade evidence: Level A →C [RCT→opinion] Recommendations: Class I: beneficial Class IIa: generally in favor Class IIb: less well established Class III: not useful, potentially harmful? AAC/AHA Task Force on Practice Guidelines. Circulation 2006;114(5)e Endorsed by SCA, STS

Valvular Heart Disease Decision to repair/replace valve should be made before surgery IOTEE should be used to confirm dx, evaluate repair + evaluate new findings (e.g., moderate AS in setting of CABG, moderate AI if ↓ EF or ↑ LVEDD, aortic root reconstruction if dilated > 5 cm) AAC/AHA Task Force on Practice Guidelines. Circulation 2006;114(5)e Endorsed by SCA, STS

IOTEE Indications Class I: valve repair, valve replacement- stentless / autograft (Ross), valve surgery in setting of endocarditis –Level of evidence= B Class IIa: all valve surgeries –Level of evidence =C AAC/AHA Task Force on Practice Guidelines. Circulation 2006;114(5)e Endorsed by SCA, STS

Aortic Stenosis Check annulus size Verify size of aortic root (mismatch? aneurysmal?) After bypass: problems w prosthesis: immobility, leaks AAC/AHA Task Force on Practice Guidelines. Circulation 2006;114(5)e Endorsed by SCA, STS

Severe Aortic Stenosis 5.7 m/s 2.0 cm 1.3 m/s AVA = 3.14 ( ) X = 0.72 cm

Severe Aortic Regurgitation T 1/2 = 84 ms Vena Contracta = 11 mm

Mitral Regurgitation AAC/AHA Task Force on Practice Guidelines. Circulation 2006;114(5)e Endorsed by SCA, STS Functional vs structural After bypass: Residual MR, MS, SAM Leaks Immobility of prosthesis

Severe Mitral Regurgitation PISA ROA PISA ROA r n =1.1cm r n =1.1cm v n =59 cm v n =59 cm v p =450 cm v p =450 cm = 2Π(1.1) 2 (59/450) = 0.99 cm 2

MR Quantitation MildSevere Jet Area (cm2)<4; <20% LA≥40% LA VC (cm)<0.3>0.6 RV (cc/beat)<30≥60 RF (%)<30≥50 ERO (cm2)<0.2≥0.4 Pulm vein flow Blunted systolicSystolic reversal LA sizeN or dilated 1+Dilated +++

SAM

Outflow Tract Obstruction

Cardiac Tamponade RA Diastolic Collapse

Type A Dissection: TEE MHMC # Type A dissection with flap extending to just superior to RCA ostium

Aortic Dissection: MHMC # Demonstration of extension of dissection distally TEE Distal Thoracic Aorta

Diabetes + Hyperglycemia  neuro injury after focal + global ischemia  myocardial infarct size  WBC function Impaired wound healing  risk infection, especially gluc > 250

Reasons for Hyperglycemia 1.  insulin requirements w obesity, steroids, stress response to surgery + CPB 2.Excess glucose in pump prime, cardioplegia 3.  gluconeogenesis + glycogen breakdown (CPB + stress response) 4.  glucose utilization: hypothermia 5.  insulin production: pancreatic hypoperfusion Smith et al: J Cardiothorac Vasc Anesth 2005;19:201

Portland Protocol: Starr Center for Cardiac Surgery. Diabetes + Deep Sternal Wound Infection Hyperglycemia - major role in impaired wound healing + deep sternal wound infection Insulin infusion + moderate control –Titrate infusion to gluc mg/dl –Start in OR, continue to POD 3  incidence to 0.3%, similar to non- diabetics

N Engl J Med 2001;345: Van Den Berge Study RCT, 1548 diabetic + non-diabetic SICU patients –60% had cardiac surgery Compared tight vs. conventional glucose control –Tight: mg/dl –Conventional: insulin only if glucose > 210; endpoint  mortality in tight group 4.6 v. 8%  infections, dialysis dependent RF, # transfusions required, need for prolonged mechanical ventilation

How Tight Should Intraop Control Be? Furnary- 99: < 200 w insulin infusion ↓ mortality Van den Berghe- 01: w insulin infusion ↓ mortality (vs ) Furnary- 03: 250) Finney- 03: < 145 Lazar- 04: 250) Ouattata- 05: < 200 w insulin infusion

MHMC Study Prospective, non-randomized, n=40 Diabetics received continuous infusion regular insulin, 10 u/m 2 /h + variable D10W, starting rate 100 ml/h or 9.4 gm gluc/h Target glucose Standardized anesthetic, bypass, cardioplegia POC glucose testing + multiple biochemical measurements J Cardiothorac Vasc Anesth 2005;19:201

MHMC Study- Results 53% achieved adequate intraop control + 35% had control by end of surgery [total =88%] 12% never had control (starting glucose ) 25% had hypoglycemia requiring D50 (mean gluc 57, range 33-74, mostly CRF pts) J Cardiothorac Vasc Anesth 2005;19:201

Smith et al: J Cardiothorac Vasc Anesth 2005;19:201

Current Approach- Diabetics Insulin infusion- mix 250 units regular insulin in 250 ml 0.9% saline Flush line w 25 ml [insulin binds to tubing] Starting dose: gluc/100 per hr, continue in ICU Target glucose Measure gluc q 1h Bolus doses can be given IV Be careful with renal failure +after CPB- accumulation of insulin + risk hypoglycemia

Cognitive Dysfunction Inability to perform normal activities after surgery 4 major domains of function 1.Verbal memory + language comprehension 2.Abstraction, visuo-spatial orientation 3.Attention, psychomotor processing speed, concentration 4.Visual memory Newman MF: SCA Annual Meeting, 2007

Newman MF: N Engl J Med 2001;344:395. Duke, n=261 Cognitive Decline, CABG

Social + Economic Costs Cognitive dysfunction –↓ quality of life –↓ return to work –Altered personality, relationships –↓ sexual function

Implications Abrupt decline in cognitive function heralds: –Loss of independence –Withdrawal from society –Death Seattle Longitudinal Study of Aging Berlin Aging Study

Potential Mechanisms 1.High-risk patients 2.High-risk surgical procedures 3.High-risk anesthetic techniques

Patient Risk Factors Predictors: ↓ baseline cognition, deficit at discharge, ↑ age, ↓ yrs of education Not predictive: EF, HTN, DM, surgical factors: XC time, CPB time Etiology: ASVD of proximal aorta, genetics, anesthetics, pre-existing brain disease Newman MF: SCA Annual Meeting, 2007

Genetic Factors ApolipoproteinE ε-4 hyp: APOE allele- ↓ cognitive outcome Single nucleotide polymorphisms: SNPs- modulate inflammation, cell matrix adhesion/interaction, lipid metabolism, vascular reactivity, PEGASUS study: –minor alleles of CRP 1059G/C + SELP 1087G/A associated w POCD Newman MF: SCA Annual Meeting, 2007

Surgical Factors: Aortic Manipulation Emboli detected by TEE after unclamping; Barbut D: 1996

Microemboli or SCADs Small capillary + arteriolar dilations: microns “Footprint” of embolic material during CPB –density correlates with CPB duration –  after CPB, most gone by 1 wk Moody DM: AnnThorac Surg 1995;59:1304

Anesthetic Factors May interact w peptides- ↑ oligomerization, amyloid deposition + protein folding Low BIS levels were associated w ↑ risk in elderly [cumulative hr BIS < 45] Longitudinal studies in progress to assess POCD, delirium + effect of anesthetics Monk TG: Anesthesiology 2004;A62 Newman MF: SCA Annual Meeting, 2007

Hyperthermia + POCD

Anesthetic Risk Factors Anesthetic agents affect release of CNS neurotransmitters –acetylcholine, dopamine, norepinephrine Effects of anesthetics on cholinergic neurons in the basal forebrain [memory regulation]? Effects of aging on choline reserves Difficult to evaluate effects of anesthesia on long term memory + cognition

Blood Trx + Blood Conservation Cardiac surgery consumes >80% blood products transfused at operation Blood products may be assoc w major morbidity + mortality: TRIM, TRALI, infection, death Trx practices vary greatly High risk pts: Elderly, Preop anemia / coagulation defect, Preop antiplatelet drugs, Redo or complex procedure, Emergency, co-morbidities

Optimal hematocrit-1 Therapeutic dilemma: Anemia is bad, but so is transfusion Anemia –↑ mortality –↓ quality of life –Jeopardizes organ viability, especially in presence of limited vasodilator reserve Gravlee GP. SCA Annual Meeting, 2007

Optimal hematocrit- 2 Therapeutic dilemma, cont’d Transfusion is bad –↑ mortality + morbidity –immediate ↑ O2 transport is limited –TRIM, ↑ inflammation [role of leukoreduction], TRALI –Viral/bacteria/parasites Gravlee GP. SCA Annual Meeting, 2007

Transfusion Avoidance Techniques High yield: –↑ preop Hct –↓ CPB priming volume –RAP: retrograde autologous priming –Effective intraop cell saver –Ultrafiltration Lower yield: –Antifibrinolytics –Protamine dosing Gravlee GP. SCA Annual Meeting, 2007

Retrograde Autologous Priming Replace crystalloid prime w pts own blood Limits degree of HD Fewer pts reach critical trx trigger Murphy GS. SCA Annual Meeting, 2007

Retrograde Autologous Priming- 2 How to do this? –Heparinize, place arterial cannula, allow pts blood to flow backwards + displace crystalloid [perfusionist: “rapping”] –Maintain SBP > 100 using small doses of PHE ( ug). Turn off vasodilators –Primary risk- hypotension Murphy GS. SCA Annual Meeting, 2007

Retrograde Autologous Priming-3 What is the data? 1.Rosengart, 98: ↑ Hct, ↓ RBC trx 2.Shapira, 98: ↑ Hct, ↓ RBC trx 3.Balachandran, 02: ↑ Hct, ↓ RBC trx 4.Eising, 03: ↑ COP, ↓ extravascular lung water+ earlier time to mobilization 5.Murphy, : ↑ Hct, trend to ↓ mortality, delirium, afib, + vent > 24 hr

Cell Salvage- 1 After bypass: transfer blood from prime to cell saver bowl for washing Can also collect shed blood for washing Hct of processed blood: 60%,  2-3 DPG but processing eliminates platelets +factors Savings: ~ 1-2 units allogeneic blood

Cell Salvage- 2 Requirements: CPB –Anticoagulated blood –Centrifuge bowl + tubing Shed Blood –Aspiration assembly –Reservoir –Tubing

Cell Salvage- 3 –Few disadvantages in heart room because have: –Dedicated perfusionist + heparinized pump prime and –Wound is clean –Risks: –Air embolism w infusion under pressure –DIC if use “cell saver suction” for thrombogenic material

Ultrafiltration Remove water + low MW substances under a hydrostatic pressure gradient Induces hemoconcentration: ↓ total body water accumulation + inflammatory mediators ↓ bleeding, blood trx, morbidity + mortality Initially validated in peds, but also adults Tassani 99; Kiziltepe 01; Leyh 01; Luciani 01;

Reasons Why Trx Avoidance Techniques Fail Had PVCs, PACS Had to start vasopressors/ inotropes Looked a little oozy BP a little low CI was a little low Pt was old Pt was high risk Gravlee GP. SCA Annual Meeting, 2007

Summary 1.IOTEE: routinely use for valves, often helpful for CABG 2.Hyperglycemia: treated w insulin infusion, target glucose < 150, especially if diabetic 3.Cognitive dysfunction: high risk pts + surgery; genetics + anesthetic factors play a role 4.Multimodal blood conservation techniques work well: RAP, cell saver, ultrafiltration, amicar, protamine dosing