Mortality Risk After Cardiac Surgery: Application of Inscor in a University Hospital in Brazil's Northeast.

Objective: To apply the InsCor in patients undergoing cardiac surgery in a university hospital in Brazil's northeast. Methods: It is a retrospective, quantitative and analytical study, carried out at the University Hospital of the Federal University of Maranhão. InsCor is a remodeling of two risk score models. It evaluates the prediction of mortality through variables such as gender, age, type of surgery or reoperation, exams, and preoperative events. Data from January to December 2015 were collected, using a Physical Therapy Evaluation Form and medical records. Quantitative variables were expressed as mean and standard deviation and qualitative variables as absolute and relative frequencies. Fisher's exact and Kruskal-Wallis tests were applied, considering significant differences when P value was < 0.05. Calibration was performed by Hosmer-Lemeshow test. Results: One hundred and forty-eight patients were included. Thirty-six percent were female, with mean age of 54.7±15.8 years and mean body mass index (BMI) equal to 25.6 kg/m(2). The most frequent surgery was coronary artery bypass grafting (51.3%). According to InsCor, 73.6% of the patients had low risk, 20.3% medium risk, and only 6.1% high risk. In this sample, 11 (7.4%) patients died. The percentage of death in patients classified as low, medium and high risk was 6.3, 7.1% and 11.1%, respectively. Conclusion: InsCor presented easy applicability due to the reduced number of variables analyzed and it showed satisfactory prediction of mortality in this sample of cardiac surgery patients.

Mortality risk after cardiac surgery: application of Inscor in a University Hospital in Brazil's northeast

Abstract Objective: To apply the InsCor in patients undergoing cardiac surgery in a university hospital in Brazil's northeast. Methods: It is a retrospective, quantitative and analytical study, carried out at the University Hospital of the Federal University of Maranhão. InsCor is a remodeling of two risk score models. It evaluates the prediction of mortality through variables such as gender, age, type of surgery or reoperation, exams, and preoperative events. Data from January to December 2015 were collected, using a Physical Therapy Evaluation Form and medical records. Quantitative variables were expressed as mean and standard deviation and qualitative variables as absolute and relative frequencies. Fisher's exact and Kruskal-Wallis tests were applied, considering significant differences when P value was < 0.05. Calibration was performed by Hosmer-Lemeshow test. Results: One hundred and forty-eight patients were included. Thirty-six percent were female, with mean age of 54.7±15.8 years and mean body mass index (BMI) equal to 25.6 kg/m2. The most frequent surgery was coronary artery bypass grafting (51.3%). According to InsCor, 73.6% of the patients had low risk, 20.3% medium risk, and only 6.1% high risk. In this sample, 11 (7.4%) patients died. The percentage of death in patients classified as low, medium and high risk was 6.3, 7.1% and 11.1%, respectively. Conclusion: InsCor presented easy applicability due to the reduced number of variables analyzed and it showed satisfactory prediction of mortality in this sample of cardiac surgery patients.

Influência da atuação fisioterapêutica no processo de ventilação mecânica de pacientes admitidos em UTI no período noturno após cirurgia cardíaca não complicada / La influencia de la acción fisioterapéutica en el proceso de ventilación mecánica de pacientes internados en UCI durante el periodo nocturno tras realizar cirugía cardiaca no complicada / Influence of physiotherapeutic practice in mechanical ventilation process of patients admitted to the ICU overnight after non-complicated cardiac surgery

RESUMO Este estudo pretendeu verificar se a presença do fisioterapeuta influencia no processo de ventilação mecânica de pacientes submetidos à cirurgia cardíaca não complicada e admitidos em UTI cardiológica no período noturno. Trata-se de estudo documental retrospectivo com pacientes adultos submetidos a cirurgia cardíaca e admitidos na UTI no período noturno nos meses de novembro de 2010 a outubro de 2011, com assistência fisioterapêutica por 12 horas (n=51) e entre novembro de 2011 e outubro de 2012, período com assistência fisioterapêutica por 24 horas (n=43), no Hospital Universitário da Universidade Federal do Maranhão. Para análise estatística, foram utilizados os testes qui-quadrado, t de Student e G, sendo os dados considerados estatisticamente significantes quando p<0,05. A duração da ventilação mecânica foi menor quando ocorreu assistência fisioterapêutica no período noturno (6,7±3,7 horas vs. 8,7±3,1 horas, p=0,02). Nesse mesmo período, o número de pacientes extubados em tempo inferior a seis horas também foi significativamente maior (53,4% vs. 27,4%, p=0,0182), assim como o número de extubações programadas (79% vs. 43,1%, p=0,009). A atuação fisioterapêutica influenciou o processo de ventilação mecânica de pacientes submetidos à cirurgia cardíaca não complicada e admitidos na UTI no período noturno, reduzindo o tempo de ventilação mecânica e aumentando o número de extubações em tempo inferior a seis horas e o número de extubações programadas durante a noite.

RESUMEN En este estudio se propone a verificar si la presencia del fisioterapeuta influencia en el proceso de ventilación mecánica en pacientes sometidos a cirugía cardiaca no complicada e internados en el sector cardiaco de una UCI durante el periodo nocturno. Estudio de carácter documental retrospectivo con pacientes adultos sometidos a cirugía cardiaca e internados en una UCI en el periodo nocturno de noviembre de 2010 hasta octubre de 2011, con cuidados fisioterapéuticos de 12 horas (n=51), y entre noviembre de 2011 hasta octubre de 2012, periodo con cuidados fisioterapéuticos de 24 horas (n=43), en el Hospital Universitario de la Universidade Federal do Maranhão, en Brasil. Para el análisis estadístico, se emplearon las pruebas chi-cuadrado, t de Student y G, siendo los datos considerados significativos estadísticamente cuando p<0,05. La duración de la ventilación mecánica ha sido menor durante el cuidado fisioterapéutico en el periodo nocturno (6,7±3,7 horas vs. 8,7±3,1 horas, p=0,02). En ese mismo periodo, el número de pacientes que extrajeron los tubos en tiempo inferior a seis horas también ha sido significativamente mayor (53,4% vs. 27,4%, p=0,0182), así como la cantidad de retirada programada de los tubos (79% vs. 43,1%, p=0,009). La acción fisioterapéutica influyó en el proceso de ventilación mecánica de los pacientes sometidos a cirugía cardiaca no complicada e internados en la UCI durante el periodo nocturno, les redujo el tiempo de ventilación mecánica y aumentó el número de retirada de los tubos en tiempo inferior a seis horas y la retirada programada durante el periodo nocturno.

ABSTRACT The aim of this study was to verify the influence of physical therapists on the mechanical ventilation process of patients who underwent non-complicated cardiac surgery admitted to the Cardiac ICU overnight. Documentary and retrospective study with adult patients who underwent cardiac surgery admitted to the ICU overnight from November 2010 to October 2011 with physiotherapeutic care for 12 hours (n=51), and from November 2011 to October 2012 with physiotherapeutic care for 24 hours (n=43), at the University Hospital of the Federal University of Maranhão. For statistical analysis, we used Chi-square, Student's t, and G tests; data were considered statistically significant when p<0.05. The duration of the mechanical ventilation was lower when physiotherapeutic care occurred at night (6.7±3.7 h vs. 8.7±3.1 h, p=0.02). In this same period, the number of patients extubated in less than 6 hours was also significantly higher (53.4% vs. 27.4%, p=0.0182), as well as the number of scheduled extubations (79% vs. 43.1%, p=0.009). The physiotherapeutic practice influenced the mechanical ventilation process of patients who underwent non-complicated cardiac surgery admitted to the ICU overnight, reducing the time of mechanical ventilation and increasing the number of extubations in less than 6 hours, as well as the number of extubations scheduled during the night.

Application of Mechanical Ventilation Weaning Predictors After Elective Cardiac Surgery

ABSTRACT OBJECTIVE: To test several weaning predictors as determinants of successful extubation after elective cardiac surgery. METHODS: The study was conducted at a tertiary hospital with 100 adult patients undergoing elective cardiac surgery from September to December 2014. We recorded demographic, clinical and surgical data, plus the following predictive indexes: static compliance (Cstat), tidal volume (Vt), respiratory rate (f), f/ Vt ratio, arterial partial oxygen pressure to fraction of inspired oxygen ratio (PaO2/FiO2), and the integrative weaning index (IWI). Extubation was considered successful when there was no need for reintubation within 48 hours. Sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), and negative likelihood ratio (LR-) were used to evaluate each index. RESULTS: The majority of the patients were male (60%), with mean age of 55.4±14.9 years and low risk of death (62%), according to InsCor. All of the patients were successfully extubated. Tobin Index presented the highest SE (0.99) and LR+ (0.99), followed by IWI (SE=0.98; LR+ =0.98). Other scores, such as SP, NPV and LR-were nullified due to lack of extubation failure. CONCLUSION: All of the weaning predictors tested in this sample of patients submitted to elective cardiac surgery showed high sensitivity, highlighting f/Vt and IWI.

Effects of Resistance Exercise Applied Early After Coronary Artery Bypass Grafting: a Randomized Controlled Trial

ABSTRACT OBJECTIVE: To evaluate the effects of resistance exercise applied early after coronary artery bypass grafting. METHODS: It is a randomized controlled trial with 34 patients undergoing coronary artery bypass grafting between August 2013 and May 2014. Patients were randomized into two groups by simple draw: a control group (n=17), who received conventional physical therapy and an intervention group (n=17), who received, additionally, resistance exercise. Pulmonary function and functional capacity were evaluated in preoperative period and hospital discharge by spirometry and the six-minute walk test. For statistical analysis, we used the following tests: Shapiro-Wilk, Mann-Whitney, Student'st and Fisher's exact. Variables withP<0.05 were considered significant. RESULTS: Groups were homogeneous in terms of demographic, clinical and surgical variables. Resistance exercise exerted no effect on pulmonary function of intervention group compared to control group. However, intervention group maintained functional capacity at hospital discharge measured by percentage of predict distance in 6MWT (54.122.7% vs. 52.515.5%,P=0.42), while control group had a significant decrease (59.211.1% vs. 50.69.9%, P<0.016). CONCLUSION: Our results indicate that resistance exercise, applied early, may promote maintenance of functional capacity on coronary artery bypass grafting patients, having no impact on pulmonary function when compared to conventional physical therapy.

Relationship between pre-extubation positive endexpiratory pressure and oxygenation after coronary artery bypass grafting / Relação entre a pressão expiratória positiva final pré-extubação e a oxigenação após revascularização cirúrgica do miocárdio

AbstractIntroductionAfter removal of endotracheal tube and artificial ventilation, ventilatory support should be continued, offering oxygen supply to ensure an arterial oxygen saturation close to physiological.Objective:The aim of this study was to investigate the effects of positive-end expiratory pressure before extubation on the oxygenation indices of patients undergoing coronary artery bypass grafting.Methods:A randomized clinical trial with seventy-eight patients undergoing coronary artery bypass grafting divided into three groups and ventilated with different positive-end expiratory pressure levels prior to extubation: Group A, 5 cmH2O (n=32); Group B, 8 cmH2O (n=26); and Group C, 10 cmH2O (n=20). Oxygenation index data were obtained from arterial blood gas samples collected at 1, 3, and 6 h after extubation. Patients with chronic pulmonary disease and those who underwent off-pump, emergency, or combined surgeries were excluded. For statistical analysis, we used Shapiro-Wilk, G, Kruskal-Wallis, and analysis of variance tests and set the level of significance at P<0.05.ResultsGroups were homogenous with regard to demographic, clinical, and surgical variables. There were no statistically significant differences between groups in the first 6 h after extubation with regard to oxygenation indices and oxygen therapy utilization.Conclusion:In this sample of patients undergoing coronary artery bypass grafting, the use of different positive-end expiratory pressure levels before extubation did not affect gas exchange or oxygen therapy utilization in the first 6 h after endotracheal tube removal.

ResumoIntrodução:Após a remoção do tubo endotraqueal e ventilação artificial, o suporte ventilatório deve ser continuado, oferecendo suprimento de oxigênio para garantir uma saturação arterial de oxigênio próxima da fisiológica.Objetivo:O objetivo deste estudo foi investigar os efeitos da pressão expiratória positiva final antes de extubação nos índices de oxigenação de pacientes submetidos à cirurgia de revascularização miocárdica.Métodos:Ensaio clínico randomizado com 78 pacientes submetidos à cirurgia de revascularização do miocárdio, divididos em três grupos e ventilados com diferentes níveis de pressão expiratória positiva final antes da extubação: Grupo A, 5 cmH2O (n=32); Grupo B, 8 cm H2O (n=26); e grupo C, 10 cmH2O (n=20). Dados do índice de oxigenação foram obtidos a partir de amostras de gases sanguíneos arteriais coletados em 1, 3 e 6 h após a extubação. Pacientes com doença pulmonar crônica e aqueles que foram submetidos à cirurgia sem circulação extracorpórea, de emergência ou combinadas foram excluídos. Para a análise estatística, foram utilizados Shapiro-Wilk, G, Kruskal-Wallis, e análise dos testes de variância e definição do nível de significância em P<0,05.Resultados:Os grupos foram homogêneos em relação às variáveis ​​demográficas, clínicas e cirúrgicas. Não houve diferenças estatisticamente significativas entre os grupos nas primeiras 6 h após extubação no que diz respeito aos índices de oxigenação e a utilização de oxigenoterapia.Conclusão:Nesta amostra de pacientes submetidos à revascularização do miocárdio, o uso de diferentes níveis de pressão expiratória positiva final antes da extubação não afetou as trocas gasosas ou utilização de oxigenoterapia nas primeiras 6h após a remoção do tubo endotraqueal.

Application of Mechanical Ventilation Weaning Predictors After Elective Cardiac Surgery.

OBJECTIVE: To test several weaning predictors as determinants of successful extubation after elective cardiac surgery. METHODS: The study was conducted at a tertiary hospital with 100 adult patients undergoing elective cardiac surgery from September to December 2014. We recorded demographic, clinical and surgical data, plus the following predictive indexes: static compliance (Cstat), tidal volume (Vt), respiratory rate (f), f/ Vt ratio, arterial partial oxygen pressure to fraction of inspired oxygen ratio (PaO2/FiO2), and the integrative weaning index (IWI). Extubation was considered successful when there was no need for reintubation within 48 hours. Sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), and negative likelihood ratio (LR-) were used to evaluate each index. RESULTS: The majority of the patients were male (60%), with mean age of 55.4±14.9 years and low risk of death (62%), according to InsCor. All of the patients were successfully extubated. Tobin Index presented the highest SE (0.99) and LR+ (0.99), followed by IWI (SE=0.98; LR+ =0.98). Other scores, such as SP, NPV and LR-were nullified due to lack of extubation failure. CONCLUSION: All of the weaning predictors tested in this sample of patients submitted to elective cardiac surgery showed high sensitivity, highlighting f/Vt and IWI.

Effects of Resistance Exercise Applied Early After Coronary Artery Bypass Grafting: a Randomized Controlled Trial.

OBJECTIVE: To evaluate the effects of resistance exercise applied early after coronary artery bypass grafting. METHODS: It is a randomized controlled trial with 34 patients undergoing coronary artery bypass grafting between August 2013 and May 2014. Patients were randomized into two groups by simple draw: a control group (n=17), who received conventional physical therapy and an intervention group (n=17), who received, additionally, resistance exercise. Pulmonary function and functional capacity were evaluated in preoperative period and hospital discharge by spirometry and the six-minute walk test. For statistical analysis, we used the following tests: Shapiro-Wilk, Mann-Whitney, Student'st and Fisher's exact. Variables with P<0.05 were considered significant. RESULTS: Groups were homogeneous in terms of demographic, clinical and surgical variables. Resistance exercise exerted no effect on pulmonary function of intervention group compared to control group. However, intervention group maintained functional capacity at hospital discharge measured by percentage of predict distance in 6MWT (54.122.7% vs. 52.515.5%,P=0.42), while control group had a significant decrease (59.211.1% vs. 50.69.9%, P<0.016). CONCLUSION: Our results indicate that resistance exercise, applied early, may promote maintenance of functional capacity on coronary artery bypass grafting patients, having no impact on pulmonary function when compared to conventional physical therapy.

Relationship between pre-extubation positive end-expiratory pressure and oxygenation after coronary artery bypass grafting.

INTRODUCTION: After removal of endotracheal tube and artificial ventilation, ventilatory support should be continued, offering oxygen supply to ensure an arterial oxygen saturation close to physiological. OBJECTIVE: The aim of this study was to investigate the effects of positive-end expiratory pressure before extubation on the oxygenation indices of patients undergoing coronary artery bypass grafting. METHODS: A randomized clinical trial with seventy-eight patients undergoing coronary artery bypass grafting divided into three groups and ventilated with different positive-end expiratory pressure levels prior to extubation: Group A, 5 cm H2O (n=32); Group B, 8 cm H2O (n=26); and Group C, 10 cm H2O (n=20). Oxygenation index data were obtained from arterial blood gas samples collected at 1, 3, and 6 h after extubation. Patients with chronic pulmonary disease and those who underwent off-pump, emergency, or combined surgeries were excluded. For statistical analysis, we used Shapiro-Wilk, G, Kruskal-Wallis, and analysis of variance tests and set the level of significance at P<0.05. RESULTS: Groups were homogenous with regard to demographic, clinical, and surgical variables. There were no statistically significant differences between groups in the first 6 h after extubation with regard to oxygenation indices and oxygen therapy utilization. CONCLUSION: In this sample of patients undergoing coronary artery bypass grafting, the use of different positive-end expiratory pressure levels before extubation did not affect gas exchange or oxygen therapy utilization in the first 6 h after endotracheal tube removal.

Effects of different PEEP levels on respiratory mechanics and oxygenation after coronary artery bypass grafting.

OBJECTIVE: To compare the effects of different levels of positive end-expiratory pressure on respiratory mechanics and oxygenation indexes in the immediate postoperative period of coronary artery bypass grafting. METHODS: Randomized clinical trial in which 136 patients underwent coronary artery bypass grafting between January 2011 and March 2012 were divided into three groups and admitted to mechanical ventilation with different positive end-expiratory pressure levels: Group A, 5 cmH2O (n=44), Group B, 8 cmH2O (n=47) and Group C, 10 cmH2O (n=45). Data about respiratory mechanics were obtained from mechanical ventilator monitor and oxygenation indexes from arterial blood gas samples, collected twenty minutes after intensive care unit admission. Patients with chronic obstructive pulmonary disease and patients submitted to off-pump, emergency or combined operations were not included. For statistical analysis, we used Kruskal-Wallis, G and Chi-square tests, considering results significant when P<0.05. RESULTS: Groups were homogeneous in terms of demographic, clinical and surgical variables. Patients ventilated with positive end-expiratory pressure of 10 cmH2O (Group C) had best compliance (P=0.04) and airway resistance values, this, however, without statistical significance. They also had best oxygenation indexes, with statistical difference in all analyzed variables, and lower frequency of hypoxemia (P=0.03). CONCLUSION: Higher levels of positive end-expiratory pressure in immediate postoperative period of coronary artery bypass grafting improved pulmonary compliance values and increased oxygenation indexes, resulting in lower frequency of hypoxemia.

Factors associated to hypoxemia in patients undergoing coronary artery bypass grafting.

INTRODUCTION: Hypoxemia is a frequent pulmonary complication in the postoperative coronary artery bypass graft. Detection of factors associated with their occurrence may indicate patients at risk for this complication, which allows tracing specific therapeutic and consequently reduce morbidity and mortality. OBJECTIVE: To identify related factors to hypoxemia occurrence in immediate coronary artery bypass graft postoperative. METHODS: In this retrospective cohort study, we studied 100 patients submitted to elective om-pump artery bypass graft , between April 2010 and December 2011, at a reference university hospital for cardiac surgery in the state of Maranhão. It was considered hypoxemia gas exchange ratio less than or equal to 300 mmHg. Associated variables with perioperative hypoxemia were defined by the Student T test, G or Mann-Whitney tests, Chi-square, or Fisher's exact test and multiple linear regression. RESULTS: Among studied variables, high body mass index (P=0.036) and smoking (P=0.024) were significantly associated with hypoxemia in the immediate coronary artery bypass graft postoperative. Hypoxemia incidence in this period was 55% and did not affects mechanical ventilation duration and Intensive Care Unit lengh of stay. CONCLUSION: In this sample, body mass index and smoking were associated to hypoxemia. These data reinforce the importance of clinical assessment to identify patients at risk for this complication, considering its high incidence in immediate postoperative period.

Factors associated to hypoxemia in patients undergoing coronary artery bypass grafting / Fatores associados à ocorrência de hipoxemia em pacientes submetidos à revascularização miocárdica

INTRODUCTION: Hypoxemia is a frequent pulmonary complication in the postoperative coronary artery bypass graft. Detection of factors associated with their occurrence may indicate patients at risk for this complication, which allows tracing specific therapeutic and consequently reduce morbidity and mortality. OBJECTIVE: To identify related factors to hypoxemia occurrence in immediate coronary artery bypass graft postoperative. METHODS: In this retrospective cohort study, we studied 100 patients submitted to elective om-pump artery bypass graft , between April 2010 and December 2011, at a reference university hospital for cardiac surgery in the state of Maranhão. It was considered hypoxemia gas exchange ratio less than or equal to 300 mmHg. Associated variables with perioperative hypoxemia were defined by the Student T test, G or Mann-Whitney tests, Chi-square, or Fisher's exact test and multiple linear regression. RESULTS: Among studied variables, high body mass index (P=0.036) and smoking (P=0.024) were significantly associated with hypoxemia in the immediate coronary artery bypass graft postoperative. Hypoxemia incidence in this period was 55% and did not affects mechanical ventilation duration and Intensive Care Unit lengh of stay. CONCLUSION: In this sample, body mass index and smoking were associated to hypoxemia. These data reinforce the importance of clinical assessment to identify patients at risk for this complication, considering its high incidence in immediate postoperative period.

INTRODUÇÃO: A hipoxemia é uma complicação pulmonar frequente no pós-operatório de revascularização miocárdica. A detecção de fatores associados a sua ocorrência pode indicar pacientes de risco para essa complicação, o que possibilita traçar terapêuticas específicas e, consequentemente, diminuir a morbi-mortalidade. OBJETIVO: Identificar fatores relacionados à ocorrência de hipoxemia no pós-operatório imediato de revascularização miocárdica. MÉTODOS: Nesta coorte retrospectiva, foram estudados 100 pacientes que se submeteram à cirurgia eletiva de revascularização miocárdica com uso de circulação extracorpórea, no período de abril de 2010 a dezembro de 2011, no Hospital Universitário de referência para cirurgia cardíaca no estado do Maranhão. Considerou-se hipoxemia índice de troca gasosa menor ou igual a 300 mmHg. A associação das variáveis perioperatórias com a ocorrência de hipoxemia foi definida por meio dos testes t de Student ou Mann Whitney, Qui-quadrado, teste G, ou Exato de Fisher, além de regressão linear múltipla. RESULTADOS: Dentre as variáveis estudadas, o índice de massa corpórea elevado (P=0,036) e o tabagismo (P=0,024) apresentaram associação estatisticamente significante com a ocorrência de hipoxemia no pós-operatório imediato de revascularização miocárdica. A incidência de hipoxemia no pós-operatório imediato foi 55%. A ocorrência de hipoxemia não interferiu nos tempos de ventilação mecânica e de estadia na Unidade de Terapia Intensiva. CONCLUSÃO: Nesta amostra, houve associação entre o índice de massa corpórea e o tabagismo com a ocorrência de hipoxemia. Esses dados reforçam a importância da avaliação clínica para identificação do paciente de risco para ocorrência dessa complicação, já que esta apresenta elevada incidência no pós-operatório imediato.

Effects of different PEEP levels on respiratory mechanics and oxygenation after coronary artery bypass grafting / Efeitos de diferentes níveis de PEEP na mecânica respiratória e oxigenação após revascularização do miocárdio

OBJECTIVE: To compare the effects of different levels of positive end-expiratory pressure on respiratory mechanics and oxygenation indexes in the immediate postoperative period of coronary artery bypass grafting. METHODS: Randomized clinical trial in which 136 patients underwent coronary artery bypass grafting between January 2011 and March 2012 were divided into three groups and admitted to mechanical ventilation with different positive end-expiratory pressure levels: Group A, 5 cmH2O (n=44), Group B, 8 cmH2O (n=47) and Group C, 10 cmH2O (n=45). Data about respiratory mechanics were obtained from mechanical ventilator monitor and oxygenation indexes from arterial blood gas samples, collected twenty minutes after intensive care unit admission. Patients with chronic obstructive pulmonary disease and patients submitted to off-pump, emergency or combined operations were not included. For statistical analysis, we used Kruskal-Wallis, G and Chi-square tests, considering results significant when P<0.05. RESULTS: Groups were homogeneous in terms of demographic, clinical and surgical variables. Patients ventilated with positive end-expiratory pressure of 10 cmH2O (Group C) had best compliance (P=0.04) and airway resistance values, this, however, without statistical significance. They also had best oxygenation indexes, with statistical difference in all analyzed variables, and lower frequency of hypoxemia (P=0.03). CONCLUSION: Higher levels of positive end-expiratory pressure in immediate postoperative period of coronary artery bypass grafting improved pulmonary compliance values and increased oxygenation indexes, resulting in lower frequency of hypoxemia.

OBJETIVO: Comparar os efeitos de diferentes níveis de pressão expiratória positiva final na mecânica respiratória e nos índices de oxigenação no pós-operatório imediato de revascularização do miocárdio. MÉTODOS: Ensaio clínico randomizado no qual 136 pacientes submetidos à revascularização do miocárdio, entre janeiro de 2011 e março de 2012, foram distribuídos em três grupos e admitidos na ventilação mecânica com diferentes níveis de pressão expiratória positiva final: Grupo A, 5 cmH2O (n=44), Grupo B, 8 cmH2O (n=47) e Grupo C, 10 cmH2O (n=45), sendo os dados da mecânica respiratória obtidos do monitor do ventilador mecânico e os índices de oxigenação por meio de gasometria arterial coletada vinte minutos após a admissão na unidade de terapia intensiva. Não foram incluídos pacientes com doença pulmonar obstrutiva crônica, cirurgias associadas, de emergência ou sem circulação extracorpórea. Para análise estatística, empregaram-se os testes de Kruskal-Wallis, Teste G e Qui-quadrado, considerando os resultados significantes quando P<0,05. RESULTADOS: Os grupos apresentaram-se homogêneos em relação às variáveis demográficas, clínicas e cirúrgicas. Os pacientes ventilados com pressão expiratória positiva final de 10 cmH2O (Grupo C) apresentaram os melhores valores de complacência (P=0,04) e de resistência das vias aéreas, esta, porém sem significância estatística. Apresentaram, ainda, os melhores índices de oxigenação, com diferença estatística em todas as variáveis estudadas, além de menor frequência de hipoxemia (P=0,03). CONCLUSÃO: Níveis mais elevados de pressão expiratória positiva final no pós-operatório imediato de revascularização do miocárdio incrementaram os valores de complacência pulmonar e melhoraram os índices de oxigenação, resultando acarretando em menor frequência de hipoxemia.