Anesthesia for noncardiac surgery in children with congenital heart disease

1. Anesthesia for noncardiac surgery in children with congenital heart disease Sheila Espina-Bertoso MD, DPBA University of the Philippines-PGH

3. Introduction • Decades of advancement in diagnostic and interventional cardiology, surgical techniques, cardiopulmonary bypass, anesthetic management, and critical care have dramatically altered the natural history of congenital heart disease (CHD). • This resulted to a decrease in morbidity and mortality in affected children and improved quality of life.

4. Introduction Anesthesiologists will encounter children with CHD for elective non-cardiac surgery at one of three stages: • Unpalliated • Partially palliated • Completely palliated ASD and PDA only congenital lesions that can be truly “corrected”

5. Introduction • Increase in life expectancy leads to increased survival rates • In some cases, children may require noncardiac surgery before undergoing procedures to repair their cardiovascular pathology.

6. Objective Review general principles of anesthetic practice with a focus on preoperative assessment, intraoperative management, and postoperative care for children with CHD having noncardiac surgery.

7. Pre-operative Assessment • 50% Dx by 1st week of life; rest by 5 years • Child’s diagnosis & current medical condition will determine preoperative evaluation • Understand the anatomic and hemodynamic function of child’s heart • Discuss case with pediatrician and cardiologist • Review diagnostic & therapeutic interventions • Above will estimate disease severity and help formulate anesthetic plan

8. Preoperative Assessment • Gather information regarding the nature of the cardiovascular disease and prior therapeutic interventions. • Determine functional status. • The history and physical examination, in addition to the laboratory data and ancillary tests provide complementary information.

9. Preoperative Assessment Based on this clinical assessment and consideration of the major pathophysiologic consequences, a systematic, detailed, organized plan should be formulated for anesthetic and perioperative management.

10. History and Physical Examination • History should focus on the status of the cardiovascular system. • Relevant information includes the type of CVD and comorbid conditions medications allergies prior hospitalizations, surgeries, anesthetic experiences, and complications elective cases.

11. History and Physical Examination • Symptomatology • tachypnea, dyspnea, tachycardia, dysrhythmias, and fatigue should be sought. • feeding difficulties and diaphoresis may represent significant symptoms in infants • decreased activity level or exercise intolerance may be of concern in older children • palpitations, chest pain, and syncope should be characterized.

12. History and Physical Examination • Should include an assessment of growth and development • History of recent illnesses such as respiratory infections or pulmonary disease

13. Physical Examination • Physical Examination • weight and height • vital signs: HR, RR, O2 sat, BP. ex1: In general, children who have undergone definitive procedures should be expected to have normal to near-normal SpO2 (≥95%). After palliative interventions, SpO2 values typically range between 75% and 85%. ex2: For those aortic arch obstruction or has had any systemic-to-pulmonary shunt, upper and lower extremity as well as right and left upper extremity blood pressure and palpation of the quality of pulses should be documented.

14. Physical Examination Airway General appearance - child's level of activity - breathing pattern - level of distress and presence of cyanosis Respiratory evaluation - quality of the breath sounds - the presence or absence of labored breathing, - intercostal retractions, wheezing, rales, or rhonchi..

15. Physical Examination Cardiac Examination • assessment of heart sounds, pathologic murmurs, and gallop rhythms • presence of a thrill, representing a palpable murmur, should be noted GI Examination • Hepatosplenomegaly

16. Physical Examination • Extremities should include examination of pulses, overall perfusion, capillary refill, cyanosis, clubbing, and edema. • Noncardiac anomalies or pathology that may affect anesthetic care (e.g., a specific syndrome complex, a potentially difficult airway, gastroesophageal reflux) should be noted.

17. Ancillary Studies and Laboratory Data In cyanotic children, CBC provides the determination of polycythemia, microcytic anemia, and thrombocytopenia. Prothrombin time, partial thromboplastin times, and international normalized ratio (INR) provide an indication of clotting ability In those receiving diuretic therapy, digoxin, or angiotensin-converting enzyme inhibitors, the determination of serum electrolytes may be useful.

18. Ancillary Studies and Laboratory Data • Blood typing and crossmatching • A recent ECG should be reviewed for changes from prior studies. • Exercise tolerance test or treadmill study

19. Ancillary Studies and Laboratory Data • Review of a recent chest Xray, including a lateral view, provides information regarding cardiac size, chamber enlargement, and pulmonary vascularity. • Recent echocardiogram, cardiac catheterizations, electrophysiologic procedures, and magnetic resonance imaging should be reviewed.

20. Goal of Pre-operative Evaluation The goals of the preoperative evaluation is to obtain the most diagnostic information with the fewest tests and the least risk, discomfort, and expense to the child.

22. Intraoperative Management Premedication • Should be routine. • This facilitates parental separation, entry into the operating room, placement of monitors, and induction of anesthesia. • Commonly used premedications include oral or intravenous benzodiazepines, opioids, and small amounts of hypnotic agents.

23. Premedication • Omit for infants < six months of age • Administer under direct supervision of Anesthesiologist in preoperative facility • Oxygen, ventilation bag, mask and pulse oximetry immediately available • Oral Premedication • Midazolam 0.25 -1.0 mg/kg • Ketamine 2 - 4 mg/kg • Atropine 0.02 mg/kg

24. Premedication • IV Premedication • Midazolam 0.02 - 0.05 mg/kg titrated in small increments • IM Premedication • Uncooperative or unable to take orally • Ketamine 1-2 mg/kg • Midazolam 0.2 mg/kg • Glycopyrrolate or Atropine 0.02 mg/kg

25. Intravenous Access To secure a good intravenous access is mandatory for administration of fluids and medications during anesthetic care.

26. Intravenous Access Regarding: Size of the intravenous catheter Central venous access Air in the intravenous infusion tubing.

27. Emergency Drugs In view of the potential for hemodynamic instability in some children with CHD that may occur at any time, drugs for emergency situations should be prepared or immediately available to the anesthesiologist.

28. Monitoring • Basic monitoring involves observation of the child, including skin color, capillary refill, respiration, pulse palpation, events on the surgical field, and color of shed blood. • Standard noninvasive monitors • blood pressure • electrocardiography (5-lead) • pulse oximetry • capnography • temperature monitoring

29. Monitoring Electrocardiography • An ECG is used to monitor heart rate, cardiac rhythm, and ST-segment analysis. Usually one or multiple leads are displayed. • Most systems use two leads: standard lead II and lead V5.

30. Monitoring Pulse Oximetry • Placement is often well tolerated • One of the earliest monitors applied during anesthetic induction. • Indicate the adequacy of peripheral perfusion and cardiac output.[

31. Monitoring Capnography • To confirm proper placement of the ETT • To assess adequacy of ventilation • To recognize certain pathologic conditions such as bronchospasm, airway obstruction, and malignant hyperthermia.

32. Monitoring Temperature Monitoring • Watch out for hypothermia • This may influence oxygen delivery (increased oxygen consumption) and emergence from anesthesia, cause detrimental changes in hemodynamics, and affect hemostasis.

33. Monitoring Urinary Output Measurements • Useful index of the adequacy of renal perfusion and cardiac output esp during cases involving major fluid shifts or blood loss, or long surgical procedures.

34. Monitoring Precordial stethoscope can be extremely helpful to monitor for changes in heart tones that may suggest early hemodynamic compromise. Invasive monitoring (A-line) may be needed depending on the level of monitoring required is influenced by the child's cardiovascular pathology, clinical condition and functional status, and the complexity and duration of the surgery or procedure being performed.

35. Monitoring • PDA • Pulse oximetry right hand to measure pre-ductal oxygenation • 2nd probe on toe to measure post-ductal oxygenation • COARCTATION OF AORTA • Pulse oximeter on right upper limb • Pre and post - coarctation blood pressure cuffs should be placed

37. Anesthetic Technique • No specific formula or recipe. • The anesthetic techniques and agents used for a particular situation should be selected in consideration of the • procedure to be performed • the child's disease process and functional status • factors such as age, physical characteristics, and preferences of the anesthesiologist must be taken into consideration.

38. Anesthetic Technique • The primary goals of anesthetic management with respect to the cardiovascular system are • to optimize systemic oxygen delivery • maintain ventricular function within expected parameters for the individual patient • ensure the adequacy of cardiac output. • always keep in mind a potential decreased cardiovascular reserve and reduced tolerance for perioperative stress. • to do a carefully titrated anesthetic, regardless of the specific agents.

39. Anesthetic technique General Anesthesia Advantage • widely accepted • ease of application • certainty of effect • the appropriate choice for most children undergoing noncardiac surgery

40. General Anesthesia DISADVANTAGES - a greater potential for wide fluctuations in the hemodynamics - prolonged recovery period.

41. Regional Anesthesia • Demonstrated to be safe and effective in children with CHD • ADVANTAGES • effect is limited to the surgical site • decreased number of systemic medications • potentially shorter overall recovery period • a more pleasant experience for the child. • may be used for post-op pain mangement

42. Regional Anesthesia DISADVANTAGE • Its use is limited in small children and may not always be effective. • There is also the potential for hemodynamic compromise, particularly in hypovolemic children or those with a fixed cardiac output, and is contraindicated in those with coagulation defects.

43. Inhalational Agents Halothane was considered for many decades the primary agent for inhalation induction in children in combination with oxygen and nitrous oxide. However, with the introduction of sevoflurane in the mid 1990s, it has replaced halothane for induction of anesthesia in many centers.

44. Inhalational Agents • The safety and efficacy of halothane vs sevoflurane in infants and children with CHD during cardiac surgery. • Sevoflurane • provides better hemodynamic stability • minimal impact on myocardial performance • advocated as the preferred anesthetic for children with heart disease.

45. Inhalational Agents NITROUS OXIDE • Enlarge intravascular air emboli • May cause microbubbles and macrobubbles to expand   obstruction to blood flow in arteries and capillaries • In shunts, potential for bubbles to be shunted into systemic circulation

46. IM & IV ANESTHETICS KETAMINE • No change in PVR in children when airway maintained & ventilation supported • Sympathomimetic effects help maintain HR, SVR, MAP and contractility • Greater hemodynamic stability in hypovolemic patients • Increases SVR, not recommended for L-R shunt CHD • Copious secretions → laryngospasm → atropine or glycopyrrolate

47. IM & IV ANESTHETICS KETAMINE • Relative contraindications may be coronary insufficiency caused by: • anomalous coronary artery • severe critical AS • hypoplastic left heart syndrome with aortic atresia • hypoplasia of the ascending aorta • Above patients prone to VF d/t coronary insufficiency d/t catecholamine release from ketamine

48. IM & IV ANESTHETICS IM Induction with Ketamine: • Ketamine 5 mg/kg • Succinylcholine 5 mg/kg or Rocuronium 1.5 – 2.0 mg/kg • Atropine or Glycopyrrolate 0.02 mg/kg IV Induction with Ketamine: • Ketamine 1-2 mg/kg • Succinylcholine 1-2 mg/kg or Rocuronium 0.6-1.2 mg/kg • Atropine or Glycopyrrolate 0.01 mg/kg

49. IM & IV ANESTHETICS OPIOIDS & BENZODIAZEPINE • Excellent induction agents in very sick children • Blunt the stress response in the pulmonary circulation elicited by airway manipulations and at the same time provide sedation and amnesia. • No cardiodepressant effects if bradycardia avoided • Fentanyl 25-100 µg/kg IV • Midazolam 0.05-0.1 mg/kg

50. IM & IV ANESTHETICS ETOMIDATE • CV stability • 0.3 mg/kg IV • Pain on injection & myoclonic movements THIOPENTAL & PROPOFOL • Not recommended in patients with severe cardiac defects • In moderate cardiac defects: • Thiopental 1-2 mg/kg IV or Propofol 1-1.5 mg/kg IV • Patient euvolemic