Resumo Fundamento Apesar de avanços em técnicas cirúrgicas e cuidados pós-operatórios em cardiopatia congênita, a morbidade cardiovascular permanece elevada. Objetivo Avaliar a associação do condicionamento pré-operatório de crianças e adolescentes com cardiopatias, mensurado por teste de caminhada de 6-minutos (TC6M) e variabilidade da frequência cardíaca (VFC), com a ocorrência de choque cardiogênico, séptico e morte no período pós-operatório. Métodos Estudo clínico prospectivo e observacional de 81 pacientes de 8 a 18 anos. No período pré-operatório foram realizados o TC6M (distância caminhada e SpO2) e a VFC. O escore de risco ajustado para cirurgia de cardiopatia congênita ( RACHS-1 ) foi aplicado para predizer o fator de risco cirúrgico para mortalidade. A ocorrência de pelo menos uma das complicações citadas foi considerada como evento combinado. Valores de p<0,05 foram considerados significantes. Resultados Dos 81 pacientes, 59% eram do sexo masculino, com idade média de 12 anos; 33% eram cianóticos; e 72% já tinham realizado cirurgias prévias. O choque cardiogênico foi a complicação mais comum, e 31% apresentaram evento combinado. Cirurgia prévia, tipo de cardiopatia atual, RACHS-1 , SpO2 em repouso, durante e após recuperação do TC6M foram selecionados para o estudo multivariado. A SpO2 após o TC6M permaneceu como fator de risco independente para aumentar a ocorrência de evento combinado no pós-operatório (OR: 0,93, IC95% [0,88 – 0,99], p=0,02). Conclusão O SpO2 após o TC6M no período pré-operatório foi o fator independente preditor de prognóstico no pós-operatório em crianças e adolescentes submetidos à correção cirúrgica; a distância caminhada e as variáveis da VFC não tiveram a mesma associação.

Abstract Background Despite advances in surgical technique and postoperative care in congenital heart disease, cardiovascular morbidity is still high. Objective To evaluate the association between preoperative cardiovascular fitness of children and adolescents, measured by the 6-minute walk test (6MWT) and Heart Rate Variability (HRV), and the occurrence of cardiogenic, septic shock and death in the postoperative period. Methods Prospective, observational clinic study including 81 patients aged from 8 to 18 years. In the preoperative period, the 6MWT (distance walked and SpO2) and HRV were performed. The adjusted risk score for surgeries for congenital heart disease (RACHS-1) was applied to predict the surgical risk factor for mortality. The occurrence of at least one of the listed complications was considered as a combined event. P values < 0.05 were considered as significant. Results Of the patients, 59% were male, with mean age of 12 years; 33% were cyanotic; and 72% had undergone previous cardiac surgery. Cardiogenic shock was the most common complication, and 31% had a combined event. Prior to surgery, type of current heart disease, RACHS-1, SpO2at rest, during the 6MWT and recovery were selected for the multivariate analysis. The SpO2at recovery by the 6MWT remained as an independent risk factor (OR 0.93, 95%CI [0.88 - 0.99], p=0.02) for the increasing occurrence of combined events. Conclusion SpO2after the application of the 6MWT in the preoperative period was an independent predictor of prognosis in children and adolescents undergoing surgical correction; the walked distance and the HRV did not present this association.

Abstract Objective: To compare physical therapy strategies involving abdominal muscle stabilization, with and without upper limb movement, in patients with sternal instability after heart surgery and during in-hospital care. Methods: This prospective, longitudinal, randomized, and comparative clinical study included 20 patients, which were divided into two groups: ARM, the arm group (n=10), and LEG, the leg group (n=10). The study involved the evaluation of scores of visual analog scales for sternal instability, pain, discomfort, functional impairment, lung function, and maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) before and after the interventions. Two protocols consisting of abdominal exercises in both groups with upper limb movements (ARM) and just abdominal activation with leg movements (LEG) were used for three weeks. Results: There were statistically significant (P≤0.01) improvements in pain, discomfort, and functional impairment scores, and in MIP (P=0.04) and MEP (P≤0.01) after intervention in both groups and just LEG showed improvement in forced vital capacity (P=0.043) and forced expiratory volume in one second (P=0.011). Conclusion: Both strategies promoted improvement in pain, discomfort, and functional impairment scores and in the values of inspiratory and expiratory pressures. Perhaps they were influenced by the time and resolution of the infection process, although exercises with upper limb movements seem to be safe in this population. The activation of the infra-abdominal muscles through leg movements seems to bring more benefits to lung function.

OBJETIVO: Comparar os efeitos de dois programas fisioterapêuticos de exercícios intra-hospitalares na função pulmonar e na capacidade funcional de pacientes no período pós-operatório de transplante cardíaco. MÉTODOS: Vinte e dois transplantados de coração foram randomizados em Grupo Controle (GC, n=11) e Grupo de Treinamento (GT, n=11). O GC realizou o programa de exercícios adotado como rotina na instituição e o GT realizou protocolo constituído de 10 fases, com exercícios incrementais: exercícios respiratórios, resistidos, alongamentos e caminhada. Os programas tiveram início no primeiro dia após a extubação e se estenderam até a alta hospitalar. Avaliou-se função pulmonar, distância percorrida no teste de caminhada dos seis minutos (TC6M) e força muscular periférica pelo teste de uma repetição máxima (1RM). RESULTADOS: Observou-se comportamento semelhante entre os dois grupos tratados, com aumentos estatisticamente significantes entre o primeiro e o segundo teste das variáveis: CVF (59% no GC; 35,2% no GT); PIMax (8,6% no GC; 53,5% no GT, PEMax (28,8% no GC; 40,7% no GT) e TC6M (44,5% no GC; 31,4% no GT). Houve aumento de força periférica pelo teste de 1RM para os músculos flexores de cotovelo, flexores de ombro, abdutores de quadril e flexores de joelho ao longo do tempo. CONCLUSÃO: Pacientes transplantados de coração se beneficiam da aplicação de programas de exercícios no período intra-hospitalar, independente do tipo de programa aplicado. Uma nova proposta de treinamento não resultou em superioridade em relação ao programa aplicado de rotina. Os protocolos de exercícios proporcionaram melhora das variáveis ventilatórias e da capacidade funcional dessa população.

OBJECTIVE: To compare the effects of two physical therapy exercise in-hospital programs in pulmonary function and functional capacity of patients in the postoperative period of heart transplantation. METHODS: Twenty-two heart transplanted patients were randomized to the control group (CG, n=11) and training group (TG, n=11). The control group conducted the exercise program adopted as routine in the institution and the training group has had a protocol consisting of 10 stages, with incremental exercises: breathing exercises, resistance training, stretching and walking. The programs began on the first day after extubation and stretched until hospital discharge. Assessed pulmonary function, distance walked in six minutes walk test (6MWT) and peripheral muscle strength by one repetition maximum test (1RM). RESULTS: Similar behavior was observed between the two groups treated, with statistically significant increases between the first and second test of the following variables: FVC (59% in CG and 35.2% in TG); MIP (8.6% in CG and 53.5% in TG), MEP (28.8% in CG and 40.7% in TG) and 6MWT (44.5% in CG and 31.4% in TG). There was an increase of peripheral strength by 1RM test, over time, to the muscle groups of the elbow flexors, shoulder flexors, hip abductors and knee flexors. CONCLUSION: Heart transplant patients benefit from exercise programs in hospital, regardless of the program type applied. A new training proposal did not result in superiority compared to routine programme applied. Exercise protocols provided improves in ventilatory variables and functional capacity of this population.

OBJECTIVE: The failure to wean from mechanical ventilation is related to worse outcomes after cardiac surgery. The aim of this study was to evaluate whether the serum level of B-type natriuretic peptide is a predictor of weaning failure from mechanical ventilation after cardiac surgery. METHODS: We conducted a prospective, observational cohort study of 101 patients who underwent on-pump coronary artery bypass grafting. B-type natriuretic peptide was measured postoperatively after intensive care unit admission and at the end of a 60-min spontaneous breathing test. The demographic data, hemodynamic and respiratory parameters, fluid balance, need for vasopressor or inotropic support, and length of the intensive care unit and hospital stays were recorded. Weaning failure was considered as either the inability to sustain spontaneous breathing after 60 min or the need for reintubation within 48 h. RESULTS: Of the 101 patients studied, 12 patients failed the weaning trial. There were no differences between the groups in the baseline or intraoperative characteristics, including left ventricular function, EuroSCORE and lengths of the cardiac procedure and cardiopulmonary bypass. The B-type natriuretic peptide levels were significantly higher at intensive care unit admission and at the end of the breathing test in the patients with weaning failure compared with the patients who were successfully weaned. In a multivariate model, a high B-type natriuretic peptide level at the end of a spontaneous breathing trial was the only independent predictor of weaning failure from mechanical ventilation. CONCLUSIONS: A high B-type natriuretic peptide level is a predictive factor for the failure to wean from mechanical ventilation after cardiac surgery. These findings suggest that optimizing ventricular function should be a goal during the perioperative period.

O objetivo do estudo foi investigar os efeitos da posição sentada, nos parâmetros ventilatórios e hemodinâmicos, em pacientes com suporte ventilatório mecânico prolongado, estáveis hemodinamicamente. Participaram do estudo 40 pacientes que foram randomizados em grupo controle (n=17) e grupo intervenção (n=23). Foram mensurados parâmetros hemodinâmicos, gasometria arterial, força muscular respiratória e ventilometria, realizados em dois momentos: primeira e segunda avaliação, com intervalo de 30 minutos entre as medidas. No grupo controle, as duas avaliações foram realizadas no leito, com a cabeceira elevada a 30°. No grupo intervenção, a primeira avaliação foi realizada no leito (30°) e a segunda, 30 minutos após transferência para a poltrona, na posição sentada (90°). A idade média da amostra foi de 64,7±11,2 anos. O resultado do estudo demonstrou que não houve diferenças em relação às variáveis, hemodinâmicas, gasométricas, capacidade vital forçada, volume minuto e volume de ar corrente. Entretanto, ocorreu aumento significativo da pressão inspiratória máxima (PImáx) no grupo intervenção (p<0.01). Concluímos que pacientes em pós-operatório de cirurgia cardiovascular em ventilação mecânica podem se beneficiar da posição sentada durante o desmame do suporte ventilatório, observado pela melhora da força muscular inspiratória (PImáx). Além disso, não foram observadas alterações hemodinâmicas com a troca de postura, sendo considerado um procedimento seguro.

The purpose was to study the effects of sitting position, in ventilatory and hemodynamic parameters, in patients under prolonged mechanical ventilation, in the postoperative of cardiovascular surgery. Participated 40 postoperative cardiovascular patients, intubated and mechanically ventilated, were randomized into control group (n=17) and intervention group (n=23). Hemodynamic parameters, arterial blood gases, respiratory muscle strength and ventilometry, were measured in two moments: first and second evaluation, with 30-minute interval between measurements. In the control group, both evaluations were performed at head of the bed elevated at 30°. In the sitting group, the first evaluation was developed at 30° and the second, (30 minutes after transfer to the armchair) in the sitting position (90°). The mean age of patients was 64.7±11.2 years. There were no differences regarding the hemodynamic parameters, blood gas analysis, forced vital capacity, minute ventilation and tidal volume. However, a significant increase in maximal inspiratory pressure (MIP) in the intervention group was observed (p<0.01). We conclude that stable patients in the postoperative period of cardiovascular surgery, mechanically ventilated, maybe benefits of the sitting position observed of increased inspiratory muscle strength. Furthermore, no significant hemodynamic changes, and it was well tolerated when the patients were transferred to the sitting position, so it was considered a safe procedure.

OBJETIVO: Demonstrar os benefícios da utilização da ventilação não-invasiva (VNI) no processo de interrupção da ventilação mecânica, no pós-operatório de cirurgia cardíaca. MÉTODOS: Estudo prospectivo, randomizado e controlado, com 100 pacientes submetidos a cirurgia de revascularização do miocárdio ou cirurgia valvar. Os pacientes foram admitidos na Unidade de Terapia Intensiva (UTI), sob ventilação mecânica e randomizados posteriormente em grupo estudo (n= 50) que utilizou VNI com dois níveis pressóricos após a extubação por 30 minutos, e grupo controle (n= 50) que fez uso apenas de cateter nasal de O2. Foram analisadas as variáveis antropométricas, os tempos correspondentes à anestesia, cirurgia e circulação extracorpórea, bem como o tempo necessário para a supressão da ventilação mecânica invasiva. As variáveis gasométricas e hemodinâmicas também foram avaliadas antes e após a extubação. RESULTADOS: Os grupos controle e estudo evoluíram de forma semelhante e não apresentaram diferença estatisticamente significante na análise das variáveis, exceto para a PaO2. A utilização da VNI por 30 minutos após a extubação promoveu melhora na PaO2 quando comparados os grupos, com p= 0,0009, mas não apresentou diferença estatisticamente significante na PaCO2 (p=0,557). CONCLUSÃO: O uso da VNI por 30 minutos após extubação produziu melhora na oxigenação do pacientes em pósoperatório imediato de cirurgia cardíaca.

OBJECTIVE: to show the benefits of the use of non-invasive positive pressure ventilation (NPPV) in the process of weaning from mechanical ventilation in the immediate postoperative period of heart surgery. METHODS: A prospective, randomized and controlled study was performed involving 100 consecutive patients submitted to coronary artery bypass grafting or valve surgery. The subjects were admitted into the Intensive Care Unit (ICU) under mechanical ventilation and randomized in a study group (n=50), which used NPPV with bilevel pressure for 30 minutes after extubation, and a control group (n=50) which only used a nasal O2 catheter. Anthropometric variables and the times of the intra-operative periods corresponding to anesthesia, surgery and cardiopulmonary bypass, as well as the time required for weaning from invasive mechanical ventilation were analysed. The arterial blood gases and hemodynamic variables were also assessed before and after extubation. RESULTS: The evolution was similar for the control and study groups without statistically significant differences of the variables analyzed except for the PaO2. On comparing the groups, the PaO2 improved significantly (p = 0.0009) with the use of NPPV for 30 minutes after extubation, but there was no statistically significant difference in the PaCO2 (p = 0.557). CONCLUSION: The use of NPPV for 30 minutes after extubation improved oxygenation in the immediate postoperative period of heart surgery.

Este estudo visou investigar o perfil dos fisioterapeutas que atuam nas unidades de terapia intensiva (UTIs) no Brasil, focalizando a direção do serviço, técnicas fisioterapêuticas empregadas e nível de autonomia em relação à ventilação mecânica invasiva e não-invasiva. Questionários foram enviados aos chefes dos serviços de fisioterapia de 1.192 hospitais registrados na Associação Médica de Terapia Intensiva, com retorno de 461 (39%) UTIs. Em 88% destas, os serviços são chefiados por fisioterapeutas; em 78%, compostos por até oito fisioterapeutas; 44,4% dos fisioterapeutas trabalham em regime de 30 horas semanais e 46,1% têm contrato de trabalho. Há assistência fisioterapêutica durante 24 horas em 33,6% das UTIs; 88% delas mantêm assistência nos finais de semana. Quanto às técnicas fisioterapêuticas, todos realizam mobilização, posicionamento e aspiração; 91,5% atuam na ventilação não-invasiva, sendo que 43% trabalham com total autonomia. Em relação à ventilação mecânica invasiva, 80% realizam extubação; 79,2% realizam regulagem e desmame do ventilador; entretanto, só 22% têm total autonomia (78% necessitam de protocolo ou opinião da equipe médica). Os fisioterapeutas brasileiros atuam, em sua maioria, em instituições privadas e assistenciais, cujos serviços são chefiados por fisioterapeutas. Têm relativa autonomia quanto às técnicas fisioterapêuticas e o manuseio da ventilação mecânica não-invasiva mas, no caso da invasiva, atuam sob diretiva da equipe médica.

The purpose of this study was to outline a profile of physical therapists who work in intensive care units (ICU) in Brazil, focusing on service management, techniques used, and the degree of therapists' autonomy regarding invasive and non-invasive mechanical ventilation. Questionnaires were sent to the heads of physical therapy (PT) services of 1,192 hospitals registered at the Brazilian Intensive Care Medicine Association and 461 (39%) ICUs replied. In 88% of these, PT services are headed by physical therapists and up to eight therapists work in 78% of the ICUs. Therapists work 30 hours a week in 44.4% of the units; 46.1% are formally hired. PT 24-hour assistance is available in 32.8% of the ICUs and on weekends, in 88%. Concerning PT techniques, all therapists perform mobilization, positioning, and aspiration; 91.5% play an active role in non-invasive ventilation, with 42.5% working with full autonomy. As to invasive mechanical ventilation, 80% perform extubation, 79.2% adjusting and weaning; however, only 22% have full autonomy (the others requiring physicians' protocol). Brazilian physical therapists work mostly in private institution ICUs, in services headed by physiotherapists, and have relative autonomy in handling PT techniques and non-invasive mechanical ventilation; as to invasive mechanical ventilation, most depend on protocols or discussions with a physician.

OBJETIVOS: Verificar as respostas ventilatória, de oxigenação e hemodinâmica de pacientes com insuficiência respiratória aguda (IResp) hipoxêmica submetidos a aplicação de ventilação mecânica não-invasiva (VMNI) no pós-operatório de cirurgia cardiovascular, buscando variáveis preditoras de sucesso, e comparar as diferentes modalidades de VMNI. MÉTODOS: No total, 70 pacientes com IResp hipoxêmica foram randomizados em uma das três modalidades de VMNI: pressão positiva contínua em vias aéreas (CPAP) e ventilação com dois níveis pressóricos (PEEP + PS e BiPAP®). Foram analisadas variáveis ventilatórias, de oxigenação e hemodinâmicas nos períodos pré-aplicação, 3, 6 e 12 horas após iniciado o protocolo. RESULTADOS: Foram excluídos 13 pacientes. Dos pacientes restantes, 31 evoluíram para independência do suporte ventilatório, constituindo o grupo sucesso, e 26 necessitaram de intubação orotraqueal, sendo considerados insucesso. Idade e níveis iniciais de freqüência cardíaca (FC) e de freqüência respiratória (FR) apresentaram valores elevados no grupo insucesso (p = 0,042, 0,029 e 0,002, respectivamente). O grupo insucesso apresentou maior número de intercorrências intra-operatórias (p = 0,025). As variáveis de oxigenação elevaram-se somente no grupo sucesso. Dentre as modalidades de VMNI, evoluíram como sucesso 57,9% dos pacientes no grupo ventilador, 57,9% no bi-nível e 47,3% no CPAP. Variáveis de oxigenação e FR apresentaram melhora somente nos grupos com dois níveis pressóricos. CONCLUSÃO: Pacientes com IResp hipoxêmica no pós-operatório de cirurgia cardiovascular apresentaram melhora da oxigenação, da FR e da FC durante a aplicação de VMNI. Em pacientes mais idosos e com valores iniciais de FR e de FC mais elevados, a VMNI não foi suficiente para reverter o quadro de IResp. Modalidades com dois níveis pressóricos apresentaram resultados superiores.

OBJECTIVE: To examine ventilatory response, oxygenation-related, and hemodynamics of patients with hypoxemic acute respiratory failure (ARF) submitted to noninvasive mechanical ventilation (NIV) during the postoperative phase of cardiovascular surgery in order to identify predictive variables of success, and to compare the different types of NIV. METHODS: Seventy patients with hypoxemic ARF were randomized to one of three modalities of NIV - continuous positive airway pressure (CPAP) and ventilation with two pressure levels (PEEP + SP and BiPAP®). Ventilation, oxygenation-related, and hemodynamics variables were analyzed at pre-application, and 3, 6, and 12 hours after the protocol began. RESULTS: Thirteen patients were excluded. Thirty-one patients progressed to independence from ventilatory support and comprised the success group, and 26 required orotracheal intubation and were considered the nonsuccess group. Age, initial heart rate (HR), and respiratory rate (RR) showed elevated levels in the nonsuccess group (p=0.042, 0.029, and 0.002, respectively). A greater number of intraoperative complications were seen in the nonsuccess group (p=0.025). Oxygenation variables increased only in the success group. Among the NIV types, 57.9% of patients in the ventilator group, 57.9% in the two-pressure levels group, and 47.3% in the CPAP group progressed with success. Oxygenation and RR variables showed improvement only in the groups with two pressure levels. CONCLUSION: Patients with hypoxemic ARF in the postoperative stage after cardiovascular surgery showed better oxygenation, RR, and HR during NIV application. In older patients and those with higher baseline RR and HR values, NIV was not sufficient to reverse ARF. The two-pressure level modes showed better results.

OBJETIVO: Avaliar os efeitos da manobra de recrutamento alveolar na oxigenação e volume corrente exalado em pacientes com hipoxemia no pós-operatório imediato de intervenção cirúrgica cardíaca. MÉTODO: Estudo prospectivo, consecutivo. Dentre 469 intervenções cirúrgicas cardíacas no período de fevereiro a abril de 2006, foram incluídos no protocolo 40 pacientes (8,5%), que na primeira avaliação na admissão da unidade de terapia intensiva cirúrgica apresentavam relação PaO2/FiO2 < 200. Nesse grupo de pacientes aplicou-se prospectivamente protocolo padronizado de manobras de recrutamento alveolar com pressão nas vias aéreas de 20 cmH2O na vigência de relação PaO2/FiO2 < 200, 30 cmH2O na relação PaO2/FiO2 < 150 e 40 cmH2O quando a relação PaO2/FiO2 persistisse inferior a 150 após manobra de recrutamento com pressão nas vias aéreas de 30 cmH2O. A pressão aplicada por meio do ventilador mecânico foi na modalidade pressão positiva contínua nas vias aéreas, por três vezes, com duração média de 30 segundos cada uma. Os parâmetros de oxigenação e volume corrente exalado foram comparados antes e imediatamente após as manobras de recrutamento. RESULTADOS: Dos 40 pacientes estudados, 30 responderam de modo favorável à manobra de recrutamento com pressão de 20 cmH2O e em 10 houve necessidade de 30 cmH2O. Nenhuma vez foi necessário aplicar manobra de recrutamento com pressão de 40 cmH2O. Após aplicação da manobra de recrutamento houve melhora significativa da oxigenação caracterizada por aumento da relação PaO2/FiO2 (p = 0,001), saturação periférica de oxigênio (p = 0,004) e do volume corrente exalado (p = 0,038). CONCLUSÃO: As manobras de recrutamento alveolar foram efetivas na correção da hipoxemia e aumento do volume corrente exalado em pacientes sob ventilação mecânica no pós-operatório imediato de intervenção cirúrgica cardíaca.

BACKGROUND AND OBJECTIVES: To evaluate the effects of the alveolar recruitment maneuver on oxygenation and exhaled tidal volume, in patients with hypoxemia, in the immediate postoperative period of cardiac surgery. METHODS: This is a prospective, consecutive study. Among the 469 cardiac surgeries performed from February to April 2006, 40 patients (8.5%) who, at the time of admission to the surgical intensive care unit, presented PaO2/FIO2 < 200, were included in the protocol. A standard prospective protocol of alveolar recruitment maneuvers with pressure of 20 cmH2O in the upper airways in the presence of the ratio PaO2/FIO2 < 200, 30 cmH2O with PaO2/FIO2 < 150, and 40 cmH2O when Pa2O2/FIO2 remained below 150 after recruitment maneuver with pressure of 30 cmH2O, was applied to this group of patients. Continuous positive pressure was applied to the airways with a mechanical ventilator, 3 times, for approximately 30 seconds each. Parameters of oxygenation and exhaled tidal volume were compared before and immediately after the recruitment maneuvers. RESULTS: Of the 40 patients in the study, 30 showed good responses to recruitment maneuvers with 20 cmH2O, and 10 cases required 30 cmH2O. It was not necessary to apply pressure of 40 cmH2O. There was a significant improvement in oxygenation after the recruitment maneuvers, demonstrated by an increase in PaO2/FIO2 (p = 0.001), peripheral oxygen saturation (p = 0.004), and exhaled tidal volume (p = 0.038). CONCLUSIONS: Alveolar recruitment maneuvers were successful on correcting hypoxemia and increasing the exhaled tidal volume in patients on mechanical ventilation in the immediate postoperative period of cardiac surgery.

JUSTIFICATIVA Y OBJETIVOS: Evaluar los efectos de la maniobra de reclutamiento alveolar en la oxigenación y volumen corriente exhalado en pacientes con hipoxemia en el postoperatorio inmediato de intervención quirúrgica cardiaca. MÉTODO: Estudio prospectivo, consecutivo. Entre 469 intervenciones quirúrgicas cardíacas entre febrero a abril de 2006, fueron incluidos en el protocolo 40 pacientes (8,5%), que en la primera evaluación en la admisión de la unidad de terapia intensiva quirúrgica presentaban relación PaO2/FiO2 < 200. En ese grupo de pacientes se aplicó prospectivamente protocolo estandarizado de maniobras de reclutamiento alveolar con presión en las vías aéreas de 20 cmH2O en la vigencia de relación PaO2/FiO2 < 200, 30 cmH2O en la relación PaO2/FiO2 < 150, y 40 cmH2O cuando la relación PaO2/FiO2 se mantuviese inferior a 150 después de la maniobra de reclutamiento con presión n la vías aéreas de 30 cmH2O. La presión aplicada por medio del ventilador mecánico fue en la modalidad de presión positiva continua en las vías aéreas, por tres veces, con una duración promedio de 30 segundos cada una. Los parámetros de oxigenación y volumen corriente exhalado fueron comparados antes e inmediatamente después de las maniobras de reclutamiento. RESULTADOS: De los 40 pacientes estudiados, 30 respondieron favorablemente a la maniobra de reclutamiento con presión de 20 cmH2O y en 10 hubo necesidad de 30 cmH2O. Ninguna vez fue necesario aplicar maniobra de reclutamiento con presión de 40 cmH2O. Después de la aplicación de la maniobra de reclutamiento hubo una mejoría significativa de la oxigenación caracterizada por aumento de la relación PaO2/FiO2 (p = 0,001), saturación periférica de oxígeno (p = 0,004); y del volumen corriente exhalado (p = 0,038). CONCLUSIONES: Las maniobras de reclutamiento alveolar fueron efectivas en la corrección de la hipoxemia y aumento del volumen corriente exhalado en pacientes bajo ventilación mecánica en el postoperatorio inmediato de intervención quirúrgica cardiaca.

OBJECTIVE: To analyze parameters of respiratory system mechanics and oxygenation and cardiovascular alterations involved in weaning tracheostomized patients from long-term mechanical ventilation after cardiac surgery. METHODS: We studied 45 patients in their postoperative period of cardiac surgery, who required long-term mechanical ventilation for more than 10 days and had to undergo tracheostomy due to unsuccessful weaning from mechanical ventilation. The parameters of respiratory system mechanics, oxigenation and the following factors were analyzed: type of surgical procedure, presence of cardiac dysfunction, time of extracorporeal circulation, and presence of neurologic lesions. RESULTS: Of the 45 patients studied, successful weaning from mechanical ventilation was achieved in 22 patients, while the procedure was unsuccessful in 23 patients. No statistically significant difference was observed between the groups in regard to static pulmonary compliance (p=0.23), airway resistance (p=0.21), and the dead space/tidal volume ratio (p=0.54). No difference was also observed in regard to the variables PaO2/FiO2 ratio (p=0.86), rapid and superficial respiration index (p=0.48), and carbon dioxide arterial pressure (p=0.86). Cardiac dysfunction and time of extracorporeal circulation showed a significant difference. CONCLUSION: Data on respiratory system mechanics and oxygenation were not parameters for assessing the success or failure. Cardiac dysfunction and time of cardiopulmonary bypass, however, significantly interfered with the success in weaning patients from mechanical ventilation.

OBJECTIVE: To assess by Doppler echocardiography the structural and functional alterations of rat heart with surgical induced extensive myocardial infarction. METHODS: Five weeks after surgical ligature of the left coronary artery, 38 Wistar-EPM rats of both sexes, 10 of them with extensive infarction, undergone anatomical and functional evaluation by Doppler echocardiography and then euthanized for anatomopathological analysis. RESULTS: Echocardiography was 100% sensible and specific to anatomopathological confirmed extensive miocardial infarction. Extensive infarction lead to dilatation of left ventricle (diastolic diameter: 0.89cm vs.0.64cm; systolic: 0.72cm vs. 0.33cm) and left atrium (0.55cm vs. 0.33cm); thinning of left ventricular anterior wall (systolic: 0.14cm vs. 0.23cm, diastolic: 0.11cm vs. 0.14cm); increased mitral E/ A wave relation (6.45 vs. 1.95). Signals of increased end diastolic ventricle pressure, B point in mitral valve tracing in 62.5% and signs of pulmonary hypertension straightening of pulmonary valve (90%) and notching of pulmonary systolic flow (60%) were observed in animals with extensive infarction. CONCLUSION: Doppler echocardiography has a high sensitivity and specificity for detection of chronic extensive infarction. Extensive infarction caused dilatation of left cardiac chambers and showed in Doppler signals of increased end diastolic left ventricular pressure and pulmonary artery pressure.