Congenital heart disease is the cause of increased mortality and morbidity in pediatric patients undergoing non-cardiac surgery. Perioperative hemodynamic instability, increased postoperative ventilator requirement, and prolonged hospital stay are the most common complications in these patients. Proper preparation is necessary before surgery to reduce the occurrence of such complications. The main goal is to have the procedure done in a well-equipped medical center with proper advice and supervision. Safe anesthesia and adequate rest should be provided by an experienced anesthesia team. Today, about 90% of children with congenital heart disease can reach adulthood, thanks to prenatal diagnosis and interventions, improved surgical techniques, and improved intensive care [1]. 30% of these patients will have at least one non-cardiac surgery by age 5 years for concomitant tracheoesophageal fistula, anorectal anomalies, cleft palate, lip, or non-cardiac anomalies attributed to the renal system.

Multiple procedures in these patients can exacerbate the hemodynamic response.In a study conducted on a group of patients undergoing non-cardiac surgery, 22% of patients with congenital heart disease experienced cardiac arrest, half of these occurring during non-cardiac surgery [2]. The presence of ventricular dysfunction with preoperative use of angiotensin-converting enzyme (ACE) inhibitors, inotropes, and digoxin has been found to be associated with prolonged hospitalization in the postoperative period. On the other hand, some airway abnormalities may complicate the course of congenital heart disease [3]. In addition, tracheal intubation of children during resuscitation requires experience and training, leading to a high complication rate [4]. Changes in systemic vascular resistance induced by general anesthetics reduce pulmonary blood flow in the presence of shunts. The concept that blood pressure is proportional to heart rate and the stroke volume, may not apply to these patients. This is because ventricular ejection does not increase when the volume of fluid loading is limited to increase stroke volume.

The most important factors determining the risk of surgical intervention in these patients were patient age, severity of cardiac abnormalities, and concomitant complications.Various studies have shown that the complexity of heart disease, the type of heart surgery, and the patient's functional capacity are effective for postoperative complications. To determine the appropriate anesthesia approach for both pathophysiological and anatomical differences, a risk assessment should be performed to reduce complications and ensure efficient use of resources [5]. For this purpose, pediatric patients with congenital heart disease were evaluated for Congenital Heart Surgery Score (RACHS-1) Aristotelian Basic Complexity Score (ABC-Score), Association for Thoracic Surgery and European Cardiothoracic Surgical Mortality Association risk assessment. Coagulation profile, Hb/Htc ratio, and electrolyte status are important in these patients. Increased Hb/Htc ratio indicates chronic hypoxia

Hb levels>20 g/dL or Htc>65% lead to hyperviscosity and decreased capillary blood flow and perfusion, leading to perioperative tissue hypooxygenation and thromboembolic complications such as stroke. May be connected. On purpose his Htc value should be up to 60%. The effect of chronic hepatic congestion on the production of clotting factors in patients with Fontan circulation should also be considered. Unfortunately, phlebotomy does not reduce the risk of stroke in these patients. Prolonged preoperative fasting also causes low viscosity and coagulopathy due to secondary polycythemia. Premedication is required for this group of patients, who can rapidly deteriorate hemodynamically, but increased PaCO2 with respiratory depression that can develop with deep sedation increases pulmonary arterial resistance and hypoxia. It may exacerbate bleeding. Therefore, preoperatively it is advised to administer 0.5 mg/kg midazolam orally 15-30 minutes before the procedure. Congenital heart disease can be associated with difficult airway management [6]. Due to the negative inotropic effects of

Anesthetics, hemodynamic monitoring is mandatory except for minor surgical interventions and interventions. In patients with Blalock-Taussig shunts, blood pressure measurements on the same side give lower results, so measurements should be taken on the contralateral arm. Temperature monitoring is essential to avoid hypothermia, maintain peripheral perfusion in polycythmic patients, and prevent metabolic acidosis. The use of ultrasonography in central venous catheterization can reduce the likelihood of thromboembolic complications. 

Anesthesia Management

The most important point in determining the anesthesia procedure is to know the current anatomic and physical status of the patient's circulatory system and to develop a specific plan. In these patients, the goal of maintaining anesthesia is to increase arterial oxygen saturation by increasing pulmonary blood flow. There are no contraindicated anesthetics for this group of patients. With a right-to-left shunt, reduced pulmonary blood flow increases minimal alveolar concentration and prolongs the induction of inhalation. In contrast, induction by intravenous agents is rapid. Bradycardia is common, but routine prophylaxis prior to induction is not recommended. If ventricular function is insufficient for induction of anesthesia, a single dose of fentanyl (25–30 mcg/kg) can stabilize hemodynamics. Hypnotics (propofol 1-3 mg/kg) and midazolam 0.1 mg/kg can be used in patients with intact ventricular function. The choice of muscle relaxant is recommended according to the duration of surgery. Rocuronium, vecuronium, cisatracurium and mivacurium are commonly used. Rocuronium appears to be beneficial because it can be neutralized with sugammadex. Neural axis blocks can be used in these patients as long as they prevent a sharp drop in peripheral vascular resistance. Lung perfusion in patients is determined by the relationship between central venous pressure and pulmonary vascular resistance. As a result of decreased myocardial pumping ability, the atrial pressure increases and the SpO2 decreases with a decrease in the pressure gradient in the pulmonary circulation. Blood flow to the lungs further reduces SpO2 and cardiac output, creating a vicious circle the use of PEEP leads to an increase in intrathoracic pressure with a concomitant decrease in preload and cardiac output, which is important in patients with Fontan circulation. Pneumoperitoneum models that lead to increased intra-abdominal pressure can reduce cardiac output by reducing venous return. Adequate volume delivery and ventilatory support play an important role in maintaining hemodynamic stability in this case. The high-risk group will be evaluated for symptoms such as Fontan's circulation, severe pulmonary hypertension, cyanosis and heart failure, valvular disease, chronic anticoagulation, and cardiac arrhythmias. The American Heart Association (AHA) and American College of Cardiology (ACC) reported that patients without these symptoms do not require specialized non-cardiac intervention centers [7].

The use of appropriate anesthesia and monitoring methods through multidisciplinary decision-making and planning and the identification of high-risk patients based on risk classification can reduce mortality and morbidity in pediatric patients with congenital heart disease.

1. Marelli, A. et al. "Brain in congenital heart disease across the lifespan: the cumulative burden of injury." Circulation, 2016, pp. 1951–1962.

2. Watkins, S.C. et al."Risks of noncardiac operations and other procedures in children with complex congenital heart disease." Ann Thorac Surg, 2013, pp. 204–211.

3. An, H.S. et al. "Airway compression in children with congenital heart disease evaluated using computed tomography." Ann Thorac Surg, vol., 2013, pp. 2192–2197.

4. Saracoglu, K.T. et al."Basic airway equipments in pediatric cardiac arrest management." Trends in Anaesthesia and Critical Care, vols. 7–8, 2016, pp. 54–58.

5. White, M.C. and J.M. Peyton. "Anaesthetic management of children with congenital heart disease for non-cardiac surgery." Continuing Education in Anaesthesia Critical Care & Pain, vol. 12, 2012, pp. 17–22.

6. Akpek, E.A. et al."Difficult intubation in pediatric cardiac anesthesia." J Cardiothorac Vasc Anesth, vol. 18, 2004, pp. 610–612.

7. American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. "2018 AHA/ACC guideline for the management of adults with congenital heart disease." J Am Coll Cardiol, vol. 73, 2019, pp. 1494–1563.