presented by: Dr/ Gamal Adel.. For non cardiac surgery TETRALOGY OF Fallot

Case I A 4 years old female with uncorrected Tetrology of Fallot, was to be operated upon for fronto-parietal SOL in the brain with associated midline shift. Examination showed pulse:97/min; BP: 135/81mmHg; RR:20/min; SpO2:89-92% with O 2 mask at 2L/min. Patient’s ECG showed normal sinus rhythm with tachycardia, T-wave inversions in lead III and V 1, strain pattern in anterior chest leads, right ventricular hypertrophy. Physical examination detected Clubbing in both hands, mild peripheral and central cyanosis.

The development of convulsions, focal neurologic abnormalities or clinical symptoms and signs of raised ICP are the alarming signs of presence of.. Brain abscess

Approach …. 1. Define cardiovascular pathology 2. Predict pathophysiology 3. Determine haemodynamic goals 4. Anticipate emergency treatments

Pathophysiological classification of congenital heart disease - Shunt lesions - Mixing lesions - Obstructive lesions - Regurgitation lesions

- Assess functional status - daily activities - exercise tolerance - ↓ cardiac reserve - cyanosis - respiratory distress with feeding - Dyspnea - Fainting attack - Fatigue - Palpitations - chest pain - Syncope - Abdominal fullness - Leg swelling - Medications  Vital signs  Airway abnormality  Associated extracardiac congenital anomalies  Tachypnea, dyspnea, cyanosis  Squatting  Clubbing of digits  Heart murmur (s)  CHF: - Jugular venous distention. - Hepatomegally - Ascitis - Peripheral edema

Pathophysiology of Fallot’s tetralogy : Essentially : 1. severe RVOT obstruction plus 2. nonrestrictive VSD With anatomic consequences of: 1.RVH 2.Overriding aorta And physiologic consequences of : 1.Rt to Lt shunt 2.Diminished pulmonary blood flow

..Shunt lesions.. (continued)  Rt-to-Lt shunt Most common cyanotic lesion NB: cyanosis plus quiet heart Diminished pulmonary blood flow Hypercyanotic “tet” spells -↓ Pulmonary blood flow = hypoxemia - Pressure overload of the Rt. ventricle

Preoperative Anesthetic Management: A- History B- physical examination C- Investigations D- Premedications E- Fasting Guidelines

INVESTIGATIONS MRI Laboratory Evaluation Cardiac Catheterization 12 Lead ECG Echocardiography chest X – Ray

Preoperative Anesthetic Considerations 1- Complete history and physical examination. 2- Review investigations. 3- Hydration should be maintained ?? 4- Premedication should be given to patients at risk for right to left shunt ?? 5- Antibiotic prophylaxis against endocarditis must be given ??

Continuing Education in anesthesia, Critical care & Pain | Volume 12 Number

AHA guidelines for bacterial endocarditis Prophylaxis in patients with cardiac conditions Endocarditis prophylaxis recommended Endocarditis prophylaxis recommended High-risk categoryHigh-risk category Complex cyanotic congenital heart disease : Complex cyanotic congenital heart disease : Transposition of the great vessels Transposition of the great vessels Tetralogy of Fallot Tetralogy of Fallot Surgically created systemic-to- pulmonary shunts or conduitsSurgically created systemic-to- pulmonary shunts or conduits Prosthetic, Bioprosthetic, Homograft valves Prosthetic, Bioprosthetic, Homograft valves Previous bacterial endocarditisPrevious bacterial endocarditis Moderate-risk categoryModerate-risk category Other congenital cardiac anomaliesOther congenital cardiac anomalies Acquired valvular dysfunctionAcquired valvular dysfunction Hypertrophic cardiomyopathiesHypertrophic cardiomyopathies Mitral valve prolapse with valvar regurgeMitral valve prolapse with valvar regurge X Endocarditis prophylaxis not recommended Negligible-risk categoryNegligible-risk category Physiologic, or functional heart murmursPhysiologic, or functional heart murmurs Surgical repair without residua beyond 6 months : ASD, PDA,VSDSurgical repair without residua beyond 6 months : ASD, PDA,VSD Cardiac pacemaker orCardiac pacemaker or implanted defibrillatorimplanted defibrillator Isolated secundum atrial septal defectIsolated secundum atrial septal defect Mitral valve prolapse without reg.Mitral valve prolapse without reg. Previous coronary artery bypass surgeryPrevious coronary artery bypass surgery Previous rheumatic heart disease without valvular dysfunctionPrevious rheumatic heart disease without valvular dysfunction

AHA guideline for antibiotic prophylaxis for genitourinary procedures: - High risk Child patient: Ampicillin 50 mg/kg & gentamicin 1.5 mg/kg IM or IV - High risk child allergic to penicillin: Vancomycin 20 mg/kg i.v bolus

Premedication Oral Premedication: - Midazolam mg/kg - Ketamine mg/kg IV Premedication: - Midazolam mg/kg titrated in small increments - Ketamine 1-2 mg/kg IM Premedication: - Uncooperative or unable to take orally - Ketamine 5 – 10 mg/kg - Midazolam 0.2 mg/kg N.B. Propranolol should be continued up to and including the day of surgery

Anesthetic Management A - Preoperative Management B - Intraoperative Management : 1- Monitoring 2- Choice of anesthetic agent 3- Maintenance of anesthesia 4- Emergence from anesthesia

Anesthesia was induced with : - Thiopentone sodium (4mg/kg) - Fentanyl (2microgram/kg) - Atracurium (0.5mg/kg) Preoperative antibiotics : - Cefazoline and Vancomycin.

Monitoring Non-invasive Clinical observation. ECG NIBP Pulse oximetry on two different limbs. Precordial stethoscope Continuous airway manometry. Multiple site temperature measurement. Invasive Volumetric urine collection. Arterial catheterization CVP PAC TEE

Choice of anesthetic Regimen Development of anesthetic regimen is based on various factors such as: - Presence and direction of shunts. - HF. - Arrhythmia. - Pulmonary circulation and lowering or maintenance of PVR.

Inhalational anaesthetic (Isoflurane) was given at 1-1.5% with 100% O 2. At the same time systemic venous resistance (SVR) was maintained by using intravenous phenylephrine boluses. (As, reduction in SVR increases right to left shunt). In addition patient was kept adequately hydrated in order to avoid hypotension. Blood loss during the procedure was 450ml which was replaced with equal amount of packed cells.

Tetralogy Of Fallot = Maintain adequate tissue oxygenation Avoid increasing O 2 demand. Maintain SVR, systemic BP. Minimize PVR. Avoid dehydration especially if polycythemic Oral premedication/induction(midazolam + ketamine). Since patient had VSD with right to left shunt so all the intravenous lines were kept air free to prevent paradoxical air embolism.

Halothane:  PBF not affecting PVR, Depresses myocardial function, alters sinus node function, sensitizes myocardium to catecholamines,  MAP,  HR,  CI,  EF. Desflurane: Pungent,  PAP and  PVR, Less myocardial depression than Halothane  HR,  SVR. Isoflurane: Pungent,  PAP not affecting PVR, Less myocardial depression than Halothane, Vasodilatation leads to  SVR →  MAP,  HR which can lead to  CI. Sevoflurane: Less myocardial depression than Halothane, more  in PAP compared with isoflurane, No  HR, Mild  SVR, Can produce diastolic dysfunction. Nitrous oxide: At 50% concentration does not affect PVR and PAP in children. However, it should be Avoided in children with limited pulmonary blood flow, PHT or  myocardial function.

Barbiturates : Not recommended in patients with severe cardiac reserve. Ketamine : No change in PVR in children when airway maintained & ventilation supportedSympathomimetic effects help maintain HR, SVR, MAP and contractility, Copious secretions (laryngospasm). Etomidate : Induction dose of 0.3mg/kg  no change in mean pulmonary artery pressure and PVR. Propofol : decrease in SBP and SVR, and increase in SBF in all patient whereas HR,PAP, PBF remained unchanged. Opiods : Excellent induction agents in very sick children as they have no cardio depressant effect, however it’s better avoided with bradycardia.

Choice of Induction Agents –Intravenous Ketamine: maintaining SVR Nacrotics: good hemodynamic stability Barbiturate: ↓both SVR and PVR –Inhalation Sevoflurane: least effect on SVR Halothane Desflurane dose-dependent ↓SVR Isoflurane pungent odor Nitrous oxide

Neuromuscular Blocking Drugs Non-depolarizing Atracuruim and vecronium have few cardiovascular side effects in children when given in recommended doses. Pancuronuim if given slowly doesn't produce HR or BP changes. if given as bolus doses it can produce tachycardia, ↑BP (through sympathomimetic effect ) Cisatracuruim and Rocuroinuim: safe Depolarizing Succinylcholine in pediatric is controversial Should be used with Atropine to avoid associated bradycardia or sinus arrest Also, if used with potent narcotic, atropine should be used to avoid severe bradycardia in children with  CR

Case II A male baby, born at 39 weeks of gestational age TOF with a birth body weight of 3050 g, was admitted at 4 days old for progressive abdominal distention and vomiting. An emergent loop ileostomy and multiple biopsies of the rectum and colon proved a diagnosis of long- segment Hirschsprung’s disease. General anesthesia was induced using sevoflurane with oxygen by facemask. Rocuronium bromide (0.6 mg/kg) was used to facilitate the tracheal intubation.

The patient’s condition remained stable until the surgeon pulled out all of the intestinal loops, at which point the oxygen saturation shown on pulse oximetry (SpO2) abruptly decreased, and the arterial blood pressure also gradually decreased. SPO 2 was noted and dropped to only 23%. The intestine showed poor perfusion and the heart rate rose to 180 beats/min. Blood gas analytical data showed metabolic acidosis, which was corrected by sodium bicarbonate. Concomitant hypothermia (35.5°C at the nasopharynx) was detected.

OR preparation Included bolus syringes of phenylephrine and epinephrine along with epinephrine infusion. In addition, Bicarbonate was also available in the room.

Cyanotic spells  Flexing the legs or Squatting position  compressing abdominal aorta  Volume administration  α-adrengeric agonist  β-blockers  Deepening anesthesia  Morphine

REGIONAL ANESTHESIA &ANALGESIA Regional blocks could be used safely in TOF in pediatric age group as sympathectomy doesn’t occur following these blocks. VD : which can Cause  oxyhemoglobin saturation in R-L shunts

Postoperative Anesthetic Management of CHD patients: Need for supplemental O2 and maintain patent airway Pain  infundibular spasm in TOF  RVOT obstruction  cyanosis, hypoxia, syncope, seizures, acidosis and death

Therefore, it is common for patients with CHD to present for non-cardiac surgery, and even in patient with corrected CHD significant residual problems such as arrhythmias, ventricular dysfunction, shunts, valvular stenosis, and PH may exist.

Thank you