Análise dos resultados do uso precoce e tardio da assistência circulatória com balão intra-aórtico (BIA) em pacientes submetidos a correção de cardiopatias com auxílio de circulação extracorpórea Analysis of the early and late use of the intra-aortic balloon pump as a method of mechanical support for the management of patients with low output syndrome, following cardiac surgery with cardiopulmonary bypass

Abstract

Este estudo tem como objetivo, a análise retrospectiva do uso precoce (intra-operatório) e tardio (pós-operatório) do balão intra-aórtico. Foram estudados 130 pacientes do Texas Heart Institute, no período de janeiro a dezembro de 1987, sendo 103 do sexo masculino e 27 do sexo feminino; a idade média dos pacientes foi de 61,5 ± 10,76 (14 a 84) anos, a média de peso foi de 75,5 ± 16,6 (42 a 134) kg, a média de superfície corpórea de 1,87 ± 0,24 (1,08 a 2,60)m² e um tempo médio de circulação extracorpórea de 98 (33 a 299) minutos e de pinçamento aórtico de 49 (10 a 122) minutos. O balão intra-aórtico foi usado em todos os pacientes por baixo débito cardíaco, em 4 associado a disrritmias retratarias a tratamento clínico e 2 por parada cardiorrespiratória, por períodos que variaram de 15 minutos a 256 horas. Os pacientes foram divididos em 6 grupos; Grupo I, pacientes que receberam o balão intra-aórtico no intra-operatório (precoce), Grupo II, pacientes que receberam o balão intra-aórtico no pós-operatório (tardio), Grupo III (pacientes com idade igual ou inferior a 65 anos), Grupo IV (pacientes com idade superior a 65 anos), Grupo V (pacientes com tempo de circulação extracorpórea de até 120 minutos) e Grupo VI (pacientes com tempo de circulação extracorpórea superior a 120 minutos) e 2 subdivisões nos grupos V e VI, subgrupo 1/. (pacientes com tempo de pinçamento de aorta menor ou igual a 60 minutos) e subgrupo 2/. (pacientes com tempo de pinçamento de aorta maior que 60 minutos). Dos 130 pacientes submetidos ao BIA, 81 (62.3%) sobreviveram e 49 (37,7%) pacientes faleceram; destes, 38 (36,2%) pertenciam ao Grupo I e 11 (44%) ao Grupo II. A sobrevida foi maior no Grupo III (68,6%) e menor no Grupo IV (51%) com pThe purpose of this study was to evaluate the intra-aortic balloon pump as a method of mechanical support for the management of patients with low output syndrome, following cardiac surgery with cardiopulmonary bypass. The results with early (intra-operative) and late (post-operative) support were compared, as well as the relationship among cardiopulmonary bypass time, aortic clamp time and mortality. Pre-operative left ventricle ejection fraction, as a prognosis index, and complications rates were also analysed. One hundred and thirty patients from Texas Heart Institute, during the period of January to December 1987, were studied retrospectively; there were 103 men and 27 women, with a mean age of 61.5 ± 10.7 (14 to 84) years. The mean weight body and body surface area were 75.5 ± 16.6 (42 to 134) kilograms and 1.87 ± 0.24 (1.08 to 2.60) square meters respectively. The mean time of cardiopulmonary bypass was 98 (33 to 299) minutes and the mean time of aortic clamp was 49 (10 to 122) minutes. All the patients had low cardiac output, associated with refractary arrythmias in 4 and after cardiac arrest in the intensive care unit in 2 patients. The intra-aortic balloon pump was left for variable periods of time from 15 minutes to 256 hours. The all cohort was divided in six groups, according to the early (intra-operative) insertion of the balloon pump (Group I), the late (post-operative) insertion (Group II), patient's age equal or inferior to 65 years Group III and Group IV age superior to 65 years, Group V and VI according cardiopulmonary bypass time up to 120 or superior to 120 minutes, and both were divided according to aortic clamp time (subgroup 1, up to 60 minutes and subgroup 2, superior to 60 minutes). The outcome was successful in 81 (62.3%) and 49 (37.7%) died (36.2% from Group I and 44% from Group II). The survival rate was greater in Group III (68.6%) than in Group IV (51 %) with p<0.05 showing statistical relevance of mortality in the older group. There were no significant associations between ejection fraction, aortic clamp time versus mortality but cardiopulmonary bypass had high statistical significance with p<0.01 for times over 120 minutes. Complications were found in 6 patients (4.6%). These data suggest that intra-aortic balloon pump is an effective mechanical support for the management of patients with low cardiac output following cardiac surgery with cardiopulmonary bypass, showing a tendency of best results when earliest applied, there is an influence of age and time of cardiopulmonary bypass over the mortality rates, suggesting that in these patients should be used more aggressive and effective circulatory support device.

Keywords

• Circulação assistida
• Balão intra-aórtico
• Assisted circulation
• Intra-aortic balloon pump