Anaesthesia for Non-cardiac Surgery in Adults with

Congenital Heart DiseasePresenter- Dr. Ankita Patni

Moderator- Dr. Murlidhar K.

Overview Common congenital heart diseases seen in Adults Long term consequences of congenital heart diseases and effect on Anesthesia management i. Pulmonary Hypertensionii. Bleeding and thrombosis riskiii. Heart failureiv. Dysrhythmias Anaesthetic managementi. Preoperative evaluationii. Pre-medicationiii. Endocarditis Prophylaxisiv. Intraoperative monitoringv. Management strategies for specific defectsvi. Post operative management

Cardiac Sequelae Pulmonary hypertension Ventricular dysfunction Dysrhythmias and conduction defects Residual shunts Valvular lesions-regurgitation or

stenosis Hypertension Aneurysms

Non-cardiac sequelae Secondary erythrocytosis Cholelithiasis Nephrolithiasis Developmental abnormalities Seizure disorders from previous

thromboembolic events or cerebrovascular accidents

Restrictive and obstructive lung disease

Long term consequences of CHD

Pulmonary Hypertension (main etiology)

Presence of long standing large and

non-restrictive defects

Increased pulmonary blood flow and

pressure to near systemic levels

Irreversible vascular changes – hypertrophy of the media, cellular

proliferation in intima, smooth muscle cell migration to sub

endothelium, progressive fibrosis

Obliteration of arterioles and small arteries

Increased pulmonary resistance and

reversal of shunt

Pulmonary Hypertension Other causes of pulmonary venous hypertension-a. Secondary to elevated ventricular end diastolic pressureb. Elevated pulmonary venous atrial pressurec. Pulmonary vein stenosis

Decreased oxygen saturation

Residual shunts

Poor lung function

Persistent decreased pulmonary blood flow

Eisenmenger Syndrome Refers to the development of pulmonary hypertension secondary to long standing left to right shunting. Non cardiac surgery should only be performed if absolutely essential. Perioperative mortality increases Predictors of mortality- Syncope Age at presentation or development of symptoms Poor functional class Supraventricular dysrhythmias Elevated right atrial pressures Low oxygen saturation (<85%> Renal insufficiency Severe right ventricular dysfunction Trisomy 21

Anaesthetic management in patients with pulmonary hypertension Minimize increase in pulmonary vascular resistance and decrease in

systemic vascular resistance. Abrupt increase in PVR precipitate acute right ventricular failure

Decreased cardiac output and oxygen desaturation

Bradycardia and cardiac arrest

Prevention Hyperventilation (with fraction of

inspired oxygen 1.0) Correction of acidosis Avoidance of sympathetic nervous

system stimulation Maintenance of normothermia Minimization of intrathoracic

pressure Use of inotropic support Inhaled nitric oxide

Regional versus general anaesthesia

Regional may produce unacceptable decreases in SVR and could exacerbate Right to left shunt.

General anaesthesia allows for optimal control of ventilation and may be preferable in patients with high risk surgery.

Bleeding and thrombosis risk

cyanosis Chronic hypoxia

Increased erythropoietin

Increased red cell mass

Increased viscosity

Bleeding and thrombosis risk Viscosity Sheer Stress Prostaglandins &

Nitric OxideTissue vascularity and arteriolar dilatation

BLEEDINGFlow in small arterioles(exacerbated by iron deficiency and dehydration)

THROMBOSIS

Bleeding and Thrombosis risk PREVENTION-Adequate hydrationPre-operative phlebotomy if HCT>65%Consider replacement of coagulation factors and plateletsIron deficiency should be corrected pre-operatively

Heart failure

Adults with corrected CHD

Increses ANP, Renin,

Aldosterone , NE

Abnormal cardiac autonomic nervous system regulation

Altered Hemodynamics Heart Failure

Left sided failure Should be Optimized in peri-

operative period with DiureticsDigoxinACE inhibitorsBeta blockers

Right sided failure No evidence based guidelines for

management of heart failure in patients with a systemic right ventricle (congenitally corrected TGA, Mustard or Senning repairs of TGA and single ventricles)

Heart Failure

Dysrhythmias CAUSE- Primary consequence of underlying congenital defect or secondary to surgical repair MOST COMMON FORM- Intraatrial reentrant tachycardia originating from right atrium. ATRIAL TACHYARRHYTHMIAS- often resistant to pharmacological treatment and results in rapid

hemodynamic deterioration. VENTRICULAR DYSRHYTHMIAS- risk factors- Decreased right or left ventricular functionPrevious ventriculotomyOlder age at initial surgery Patients who are repaired late exposed to longer periods of cyanosis, volume overload,

pressure overload Increased myocardial fibrosis and associated slowing of conduction Increased risk of Arrhythmias

Acute hypoxemia can provoke ventricular dysrhythmias as subendocardial myocardial perfusion is already impaired in hypertrophied myocardium

Pre-operative Evaluation Multidisciplinary APPROACH- anesthesiologists, cardiologists,

intensivists, and surgeons Look for echocardiogram and cardiac catheterisation to become

familiar with patient’s anatomy and physiology ANTICIPATE intraoperative events

ASSESS perioperative risk- Increased with Poor functional class

Pulmonary HTNCHFCyanosisMajor surgery ( OLV, changes in position-prone,trendelenberg)

Pre-medication Psychological preparation is important

ANXIOLYTICS and HYPNOTICS

Hypoventilation and Hypercapnia

Cautious!!

Increased Pulmonary Vascular Resistance ( particularly in patients with underlying pulmonary HTN or Systemic to Pulmonary shunts)

Endocarditis Prophylaxis AHA has recently published updated guidelines for the prevention of IE. Only patients with cardiac conditions associated with the highest risk of

adverse outcomes should continue antibiotic prophylaxis before surgery- Previous endocarditisUnrepaired CCHD Completely repaired congenital heart defects during the first 6 months

after the procedure Repaired CHD with residual defects at the site (which inhibit

endothelialisation)

Intraoperative Monitoring

Standard conventional monitoring

Direct examination

Pulse oximetry

ECG

Arterial blood pressure

Capnography

Temperature

Signify increase in Pulmonary vascular resistance

Increase Right to left shunt Decrease pulmonary blood flow

through shunts

Increase in left to right shunt may not be detected by pulse oximetry and oxygen saturation may be maintained even if systemic cardiac output is severely compromised.

Pulse oximetry

• EtCO2 underestimates PaCO2 in the case of Right to Left shunting

• Knowledge of the Anatomy and Physiology of specific palliative repairs is important for choosing appropriate monitoring

• Congenital defects associated with inadequate PBF are palliated with systemic to pulmonary shunts

Intraoperative monitoring

Classic Blalock Taussig shunt • End to side anastomosis of

the subclavian and pulmonary arteries

• Significance- Arterial pressure and SpO2 cannot be measured on the ipsilateral side

Glenn shunt• Bidirectional

cavopulmonary anastomosis

• End to side anastomosis of the divided SVC to PA

Fontan shunt• Total cavopulmonary

connection• Pulmonary and systemic

circulations are totally separated by diverting all the systemic venous return to the PA, usu. Without interposition of a sub-pulmonic ventricle.

Monitoring Alterations in intracardiac anatomy complicate the placement of central venous

catheters in palliated adults CVP values interpretation will be different. Eg. In Fontan; CVP ~ mean PAP In Intraatrial Buffle(Mustard or Senning procedure) ; PAC placement is difficult or

impossible. Vascular access --- may be difficult --- previous catheterization Invasive arterial pressure monitoring – Essential – sensitive to sudden changes in

preload, SVR and PVR TEE – might be useful – monitor intravascular volume status and ventricular

function

Major objective- Promote tissue O2 delivery

Prevent arterial desaturation

Maintain a balance between

pulmonary and systemic flows

Optimize HCT

Management strategies for specific defects

Management strategies for specific defects

Management strategies for specific defects

Management strategies for specific defects

Management strategies for specific defects

UNIVENTRICULAR HEART- eg. Fontan – bypasses right ventricle, leaving passive non pulsatile flow from both SVC and IVC to PA• Any factor that increases PVR – decreases PBF – Arterial desaturation.• Fontan patients frequently present with complications – supraventricular dysrhythmias, restrictive lung

disease, thromboembolic complications and hepatic dysfunction.• Both procoagulant and anticoagulant effects are observed with Fontan as a result of liver dysfunction,

factor loss in patients with protein losing enteropathy – Increased Risk of Bleeding• Patients with a Fontan circulation should maintain an arterial saturation above 90%. If <90%, further

evaluation for venovenous collaterals, AVM or residual shunt.

Anesthetic agent of choice

• Maintain hemodynamic stability• Preferred ETOMIDATE

•Increase PVR, maintain SVR and ventricular performance (not used in adults)•Beneficial effects seen in children undergoing sevoflurane anesthesiaKETAMINE•Most depress myocardial contractility and decrease SVR– Adverse effect on tissue oxygen delivery during induction of anesthesia•Choice of a specific volatile or IV agent should be based on patient’s physiology and overall goal of balancing pulmonary and systemic blood flow

OTHERS

Specific intraoperative considerations with shunts All IV lines must be meticulously DEAIRED to decrease the risk of systemic air

embolization Hemodynamic effects of ventilation strategies, positioning, pharmacological agents,

and blood loss must all appropriately BALANCE pulmonary and systemic blood flow. Ventilation with High Airway Pressure can COMPROMISE venous return, increase PVR

and exacerbate Right to Left shunt. Inadequate anesthesia and sympathetic nervous system STIMULATION might increase

SVR and exacerbate Left to Right shunting, reducing systemic cardiac output. TRENDELENBURG position– Increase CVP– Cerebral hypoperfusion in a patient with

Glenn or Fontan. Systemic HYPOTENSION– decrease PBF– Arterial Desaturation, in a patient with a

systemic to pulmonary artery shunt.

Post op management Managed in ICU experienced with caring for adults with CHD Major RISKS include :- BleedingDysrhythmiasThromboembolic events In case of pulmonary HTN, oral PULMONARY VASODILATORS such as

sildenafil and inhaled nitric oxide may be beneficial.

Thank You