IJCS | Volume 33, Nº4, July and August 2020

335 Table 4 - Distribution of hospital mortality in 20 patients admitted to a pediatric cardiac intensive care unit by RACHS-1 score categories (2013-2014) RACHS-1 Observed mortality n (%) Expected mortality (%)* Category 1 2 (5.1) 0.4 Category 2 2 (4) 3.8 Category 3 11 (13.3) 9.5 Category 4 5 (38.5) 19.4 (*) Jenkins et al., 2002. Guimarães & Guimarães Profile of a pediatric cardiac ICU Int J Cardiovasc Sci. 2020; 33(4):331-336 Original Article 35% of the cases treated clinically and 12% of those undergoing percutaneous procedures. Valvuloplasty and mitral valve replacement accounted for most of the procedures. According to Muller, 10 the mitral valve is affected in most cases of rheumatic carditis, while aortic valve lesions are present in approximately 30% of the cases. In our study, 23% of patients with rheumatic heart disease treated surgically underwent double valve replacement. No case of pulmonary or tricuspid valve disease was reported, corroborating the findings of this author 10 who described that lesions related to these both valves have transient anatomic features in the acute phase, corresponding to an estimated 5% of the cases. The most common diagnosis among acyanotic heart defects was IVC (24.7%), similar to previously reported by Aragao et al., (21%) 17 and Miyague et al., (30.5%). 23 These same authors reported the prevalence of 7.7% and 19.1% for IAC and 18%and 17% for PAC, respectively. We found a prevalence of 13.2%of these conditions. Tetralogy of Fallot was the most frequent cyanotic congenital heart disease (32.1%), corroborating the studies by Miyague et al. (9.9%), 23 Borges et al. (8.1%) 16 and Aragao et al. (14%), 18 but contrasting with the findings of Nina et al., 21 describing the presence of this anatomical malformation in only 4% of the patients. With respect to mortality rate in the study group (11.1%), 0.65% of deaths were related to acquired heart diseases, mostly (10.35%) congenital heart defects. This is similar to that reported by Guitti 15 (10%) and lower than the percentage reported by Nina et al. (17.2%). Regarding the RACHS-1 score, although 44.9% of the patients were classified in category 3, mainly those undergoing palliative surgeries (33.7%) related to the systemic-to-pulmonary shunt (modified Blalock-Taussig shunt), the highest mortality was found in category 4 (38.5%) followed by category 3 (13.3%). In agreement with Jenkins et al., 14 the higher the risk category, the higher the mortality. Similar findings were reported in national and international studies. 19,21,22,24 In our study group, mortality predictors were infants aged between 28 days and one year (61.8% of deaths, p = 0.001), diagnosis of cyanotic congenital heart disease (68.8% of deaths, p = 0.007) and time of extracorporeal circulation greater than 120 minutes (52.9%, p = 0.018). Comparisons of these findings with other tertiary care centers would provide information that may serve as a basis for a more detailed knowledge of these patients’ profile, and development of indicators to guide the prediction of technological support and reassessment of processes, contributing to the performance in these centers. Limitations of these studies were those expected and inherent to cross-sectional designed studies, particularly those related to data collection. There were no electronic medical records, which made it difficult to identify some clinical variables, such as age, body weight and medical history of the patients. The scarcity of the literature on the application of the RACHS-1 was another limitation. Conclusion Congenital heart diseases were more prevalent than acquired heart diseases. Surgical treatment was the main reason of admission of the children to the pediatric cardiac ICU. Total repair surgeries were more prevalent than palliative surgeries. Hemodynamic complications were more commonly seen in patients undergoing surgical interventions. In this study, patients with cyanotic congenital heart diseases, aged between 28 days and one year, undergoing surgical treatment, with extracorporeal circulation duration longer than 120 minutes are at higher risk of death. Although most patients were classified as risk category 3 in the RACHS-1 score, the highest mortality rate was associated with risk category 4. Author contributions Conception and design of the research: Guimarães JR. Acquisition of data: Guimarães JR. Analysis and interpretation of the data: Guimarães ICB. Statistical analysis: Guimarães JR. Writing of the manuscript: