Anesthesia Management for Pediatrics with Congenital Heart Diseases Who Undergo Cardiac Catheterization in China

Objectives The goal of this study was to summarize anesthesia management for pediatrics with congenital heart diseases who undergo cardiac catheterization procedure in China. Methods The relevant articles were identified through computerized searches in the CNKI, Wanfang, VIP, and PubMed databases through May 2020, using different combinations of keywords: “congenital heart diseases,” “pediatric,” “children,” “anesthesia,” “cardiac catheterization,” “interventional therapy,” “interventional treatment,” “interventional examination,” and “computed tomography.” Results The database searches identified 48 potentially qualified articles, of which 25 (9,738 patients in total) were determined to be eligible and included. The authors collect data from the article information. Anesthesia methods included endotracheal intubation or laryngeal mask ventilation general anesthesia, monitored anesthesia care, and combined with sacral canal block. Anesthesia-related complications occurred in 7.41% of the patients and included dysphoria, respiratory depression, nausea, vomiting, cough, increased respiratory secretion, and airway obstruction. The incidence of procedure-related complications was 12.14%, of which the most common were arrhythmia and hypotension. Conclusions For pediatric patients with congenital heart diseases who undergo cardiac catheterization procedures in China, arrhythmia and hypotension are the most common procedure-related complications. Monitored anesthesia care is the commonly used anesthesia methods, and dysphoria, cough, nausea, vomiting, and respiratory depression are frequent complications associated with anesthesia.


Introduction
Congenital heart diseases (CHDs) are the most common form of congenital abnormality. Marelli et al. [1] reported that CHD occurs in over 1% of newborns, and the morbidity is similar in China. Cardiac catheterization is an integral part of medical management for pediatric patients with CHD [2]. Cardiac catheterization and angiography were established and widely used by the 1950s [3]. Cardiac catheterization can avoid the trauma of thoracotomy and the potential risk of cardiopulmonary bypass (CPB), eliminate the possible adverse consequences of CPB, and significantly shorten the length of hospital stay. Cardiac catheterization for CHD has developed rapidly in recent years, and the main emphasis has shifted toward innovative therapeutic interventions [4]. ese advances allow children with CHD many additional nonsurgical options, increase patients' surgery-free intervals, and can possibly postpone or even replace open heart surgery. us, cardiac catheterization has gradually become the preferred and most common method for treating children with CHD. However, the optimal anesthesia method for cardiac catheterization of CHD in children is still controversial.
is paper included articles published in various regions of China on cardiac catheterization of CHD in children, in order to find out the optimal anesthesia method and summarize the anesthesia experience and complications.

Search Strategy.
Relevant articles were identified through computerized searches in the CNKI, Wanfang, VIP, and PubMed databases through May 2020 using different keywords combinations including "congenital heart diseases," "pediatric," "anesthesia," "children," "cardiac catheterization," "interventional therapy," "interventional treatment," "interventional examination," and "computed tomography." e inclusion criteria mainly focused on retrospective articles and controlled studies. e exclusion criteria included the following: ① studies published before 2000, ② duplicate publication, ③ a sample size of fewer than 100 cases, ④ conference abstracts, and ⑤ studies that lacked details.
Both authors (C. M. X and Y. T. Y) independently reviewed the titles and abstracts of all the candidate reports for eligibility and excluded those that were obviously ineligible. e eligibility of the remaining reports for final inclusion was subsequently determined by examining the full text.

Data Abstraction.
e following data from the included articles were abstracted to a data collection form by each author independently: ① author, year, journal of publication, and research institutions; ② total number of patients, sex, age, weight, operation methods, anesthesia methods, method of airway administration, and drugs; ③ intraoperative monitor; ④ anesthesia-and procedure-related complications. Disagreements were resolved by discussion between both authors during the data abstraction process.

e Articles.
As depicted in the flowchart (Figure 1), the database search identified 48 potentially qualified articles. Of these, 25 (9,738 patients in total, 4,602 males and 4,399 females) articles were determined to be eligible and included. Descriptive analyses of these articles are presented in Table 1. e patients were between 23 days and 14-year-old and weighed from 3 to 39 kg, including 2,004 cases of diagnostic angiography examination and 7,734 cases of interventional therapy. e interventional therapy cases were further subdivided into occluder implantation (7,215 cases), balloon dilation (468 cases), and pacemaker implantation and radiofrequency ablation (51 cases) ( Figure 2).

Anesthetic Methods.
In our study, Chinese anesthesiologists used endotracheal intubation [6,8,11,19,24,28] or laryngeal mask [19] general anesthesia, monitored anesthesia care (MAC), and occasionally chose sacral canal block [11,25]. Because Song et al. [11] did not indicate the number of cases of each anesthesia method in the article, the number of cases of endotracheal intubation, laryngeal mask, sacral canal block and MAC was 770, 120, 313, and 5,890, respectively ( Figure 3). MAC was the most common option. In addition to those patients who were preoperatively considered for endotracheal intubation to control breathing, 31 (0.32%) patients underwent unexpected emergency endotracheal intubation in our research ( Table 2).

Anesthetic Drugs.
In our study, the reported anesthesiarelated premedication, induction, and maintenance drugs are shown in Table 3, a variety of anesthesia-related drugs were used either alone or in combination, and 12 articles reported the use of preoperative drugs such as atropine, anisodamine, penehyclidine, diazepam, pethidine, morphine, and midazolam. Induction drugs like ketamine, midazolam, fentanyl, propofol, scopolamine, and penehyclidine were reported in intravenous anesthesia in 23,19,11,4,4, and 3 articles, respectively.

3.5.
Complications. In our study, there were a total of 722 (7.41%) cases of anesthesia-related complications (Table 4), and the incidence of dysphoria was 2.09% (204 patients reported in 6 articles). Respiratory-and airway-related adverse events were the most common anesthesia-related complications and occurred in 3.88% (a total of 378 patients in 20 articles), including respiratory depression, cough, bronchospasm, laryngospasm, increased respiratory secretion, and airway obstruction. Respiratory depression included ① a low respiratory rate (RR) (<12 breaths/min), ② apnea lasting more than 15 seconds, ③ a >20% drop in SpO 2 , ④ an oxygen partial pressure (PO 2 ) ≦40 mmHg, and ⑤ a PetCO 2 >50 mmHg. e incidence of procedure-related complications was 12.14% (1,182 cases), the highest incidence was arrhythmia, and the second highest was hypotension ( Table 5). Details of the fatal cases are shown in Table 6.

Discussion
Cardiac catheterization remains the gold standard for diagnosis and management in multiple forms of CHD [2]. During interventional cardiac catheterization, the patients should be quiet, cooperate, immobile, and with stable hemodynamics, and unobstructed airways and hypoxia should be avoided; consequently, anesthesia is often required. Ramamoorthy et al. [30] reported that anesthetic risk is higher in pediatric cardiac patients than in the general pediatric population.
Messeha and El-Morsy [31] reported that anxiety and psychological trauma due to maternal deprivation were major challenges in pediatric anesthesia. Preanesthetic medication decreases this anxiety and psychological trauma and facilitates the induction of anesthesia without delaying  recovery. In this study, 12 articles reported the use of preoperative drugs (Table 3), focused on sedation, and reduced respiratory secretions. In the meta-analysis of Peng et al. [32], they compared dexmedetomidine premedication with midazolam or ketamine premedication or placebo in children, the methods of administering dexmedetomidine premedication including IM, PO, IV, and intranasal instillation, and suggested that dexmedetomidine is superior to midazolam premedication because it resulted in enhanced preoperative sedation and decreased postoperative pain.
In our study, when patients entered the cardiac catheterization laboratory, ECG, HR, SpO 2 , and NIBP were routinely monitored, and close attention was paid to their breathing. PetCO 2 and blood gas were further monitored when necessary. PetCO 2 can detect the presence or absence of air exchange as well as airway obstruction, hypoventilation, and apnea, and it has been a standard operating room method of monitor for years. Accordingly, there is increasing interest in the use of PetCO 2 outside the operating room [33,34], and newer sedation guidelines encourage its use [35]. Routine use of capnography has reduced anesthesia-related adverse outcomes [36]. When using capnography, cyanotic heart diseases patients warrant special attention. Friesen and Alswang [37] reported that PetCO 2 correlated well with PaCO 2 , but besides cyanotic heart disease patients, these patients needed blood gas analysis.
Singh et al. [38] reported that nontracheal intubation general anesthesia is commonly used in the interventional cardiac catheterization of pediatric patients with CHD. In   regulates pulmonary vascular resistance (PVR), and does not involve airway obstruction; the depth of anesthesia is easily regulated and deep enough to blunt the reflexes to painful stimuli and ensure immobility [39]. However, positive pressure ventilation reduces venous return, alters the flow across valves and shunts, decreases the metabolic rate,  Journal of Interventional Cardiology decreases oxygen consumption, and further alters hemodynamics [40]. erefore, most anesthesiologists choose MAC for the children with CHD during cardiac catheterization. e anesthesia induction method should be selected according to age, premedicant dosage, venous channel existence, lesions type, blood vessel function, and the possible response to different anesthetic drugs. And Behnaz et al. [41] reported the effect of sevoflurane and propofol on pulmonary arterial pressure during cardiac catheterization in children with CHD. In our study, intravenous induction was most commonly used. Ketamine often used in combination with propofol, midazolam, atropine, or penehyclidine usually provides a stable hemodynamic and respiratory profile with good recovery time and minimal delirium [42,43]. In brief, we found that many different drugs combinations have been used safely and successfully with general anesthesia and sedated patients. e anesthesiologist must understand the limitations of each method and has a firm grasp of the basic knowledge of circulation physiology characteristics of pediatric patients with CHD. When physicians prepare to puncture the femoral artery or vein, anesthesiologists should increase the depth of anesthesia and the physician should administer 1% lidocaine local anesthesia at the puncture site.
In this study, the incidence of anesthesia-related complications was 7.41% (722 patients in Table 4), slightly higher than the 6% reported by Tokel et al. [44] and Behnaz et al. [45] perhaps because Tokel et al. only collected 2,662 patients reported from a single center over a five-year period. e incidence of procedure-related complications was 12.14% (1,182 cases reported in 15 articles); of these, arrhythmia and hypotension occurred in 9.24% (900 cases reported in 9 articles) and 2.21% (215 cases reported in 4 articles), respectively. Fuwai Hospital reported [46] that, from 1986 to 2009, a total of 6,029 patients with CHD were treated by interventional therapy, the incidence of procedure-related complications was 388 cases (6.44%) (in addition to arrhythmias), and the mortality rate was 0.08% (5 patients). Tokel et al. [44] reported that the incidence of adverse events in cardiac catheterization was 20%, with a mortality rate of 1.4%.
In cardiac catheterization, the arrhythmias were usually transient and included premature ventricular beats (polygenesis or synchrony), short episodes of ventricular tachycardia, atrial arrhythmias, ventricular tachycardia, atrioventricular block, and bradycardia. e majority of arrhythmias were related to stimulation of the atrial or ventricular wall by the catheter, and when the catheter was withdrawn immediately, the arrhythmia disappeared in most cases. If the arrhythmia remained unresolved, some relevant antiarrhythmic drugs should be considered, such as lidocaine, atropine, propafenone, and supplementary volume. Almost all sedative drugs cause peripheral vascular dilatation, plus the patient loses blood during femoral arteriovenous puncture, which commonly leads to intraoperative hypotension. e appropriate treatment method is to replenish volume. Other procedure-related complications included occluder detachment, emergency open heart surgery, wire looping or kinking, pericardial tamponade, heart failure, and pulmonary edema. ese complications are relatively serious; thus, they need to be recognized quickly and brought to the physician's attention.  In our study, 25 (0.26%) patients experienced cardiac arrest, and recovery occurred after timely and effective cardiopulmonary resuscitation. Boston Children's Hospital [47] reported that the risk of cardiac arrest was 0.96% and was associated with procedural and system factors.
Fortunately, death is uncommon. Five patients died in our group, a mortality rate of 0.05% (Table 6), and all the cases involved were complex cyanotic patients with CHD undergoing right heart operations. Bergensen et al. [48] reported a mortality rate of 0.29% among 3,855 cases from six institutions, seven out of the eleven deceased patients were neonates, and cyanotic patients had an increased risk of mortality. Death after cardiac catheterization seems to be more related to the patient's general status than with the procedure itself.

Conclusions
For pediatric patients with congenital heart diseases who had undergone cardiac catheterization procedure in China, arrhythmia and hypotension are the most common procedure-related complications. Monitored anesthesia care is the commonly used anesthesia methods, and dysphoria, cough, nausea, vomiting, and respiratory depression are frequent complications associated with anesthesia.

Data Availability
e data used to support the findings of this study are present within the article.

Conflicts of Interest
e authors declare that they have no conflicts of interest.