Daniel Lago Borges

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 Fishers 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.

Effects of Positive End-Expiratory Pressure on Mechanical Ventilation Duration after Coronary Artery Bypass Grafting: A Randomized Clinical Trial

Patients undergoing cardiac surgery remain on mechanical ventilation postoperatively until they regain consciousness. Positive end-expiratory pressure (PEEP) may influence the duration of mechanical ventilation after coronary artery bypass grafting (CABG). The aim of this study was to compare the effects of different levels of PEEP on the duration of mechanical ventilation after coronary artery bypass grafting. This was a randomized clinical trial with 136 patients undergoing CABG between January 2011 and March 2012. We divided the patients into three groups with different levels of PEEP at the onset of mechanical ventilation: Group A, PEEP=5 cmH2O (n=44); Group B, PEEP=8 cmH2O (n=47) and Group C, PEEP=10 cmH2O (n=45). Mechanical ventilation time was obtained from a Physical Therapy Evaluation Form. We excluded patients with chronic obstructive pulmonary disease and those requiring concomitant, emergency or off-pump surgeries. For statistical analysis, we used the Kruskal-Wallis, G and Chi-square tests, with p<0.05 considered significant. From the point of weaning from mechanical ventilation until 12 hours after intensive care unit (ICU) admission, we saw a statistically different duration of mechanical ventilation between groups (p=0.029). In Group A, the average mechanical ventilation time was 6.7±3.2 hours; it was 6.8±3.3 hours in Group B and 5.1±2.9 hours in Group C. The use of higher levels of PEEP was associated with shorter duration of mechanical ventilation in postoperative CABG patients.

Correlation between Length of Hospital Stay and Gait Speed in Patients Submitted to Cardiac Surgery

Fundamento: As doencas cardiovasculares tem aumentado em todo o mundo nas ultimas decadas devido ao aumento na ocorrencia de fatores desencadeantes. No periodo pos-operatorio de cirurgia cardiovascular, os pacientes experimentam um declinio funcional, que pode ser potencializado pelo tempo de internacao hospitalar. Portanto, e importante avaliar a capacidade funcional destes pacientes. Objetivo: Comparar o tempo de internacao hospitalar com a velocidade da marcha em pacientes submetidos a cirurgia cardiaca. Metodo: Estudo de coorte prospectivo, realizado no Instituto Nobre de Cardiologia (Incardio) da Santa Casa de Misericordia (Feira de Santana, Bahia). Na alta hospitalar, todos os pacientes foram avaliados com o teste de caminhada de 6 minutos (TC6). O tempo de internacao hospitalar no periodo pos-operatorio foi tambem registrado no momento da avaliacao e correlacionado com a velocidade da marcha. Utilizamos o teste de Kolmogorov-Smirnov para avaliar a suposicao de normalidade e a correlacao de Spearman para correlacionar a velocidade da marcha com a idade, tempo de hospitalizacao e com a duracao da circulacao extracorporea (CEC) e da ventilacao mecânica invasiva (VMI). Todas as conclusoes foram baseadas em um nivel de significância de 5%. Resultados: Ao todo, 64 pacientes foram incluidos (33 homens [51,5%], idade media 57,2 ± 14,06 anos). A distância media percorrida pelos pacientes foi de 375,8 ± 197,6 metros, a media da velocidade da marcha foi de 0,98 ± 0,53 m/s e a media de permanencia hospitalar foi de 8,2 ± 2,3 dias. Foi observada uma fraca correlacao entre o tempo de internacao hospitalar e a velocidade da marcha (r = 0,27 e p = 0,02). Conclusao: A duracao da hospitalizacao mostrou uma fraca correlacao com a velocidade da marcha na alta hospitalar em uma amostra de pacientes submetidos a cirurgia cardiaca. Registro do estudo: Registrado no CAAE (41151214.5.0000.5654) em 26 de junho de 2015.

Effects of Aerobic Exercise Applied Early After Coronary Artery Bypass Grafting on Pulmonary Function, Respiratory Muscle Strength, and Functional Capacity: A Randomized Controlled Trial

BACKGROUND Physical activity is beneficial in several clinical situations and recommended for patients with ischemic heart disease, as well as for those undergoing cardiac surgery. METHODS In a randomized controlled trial, 34 patients underwent coronary artery bypass grafting. A randomized control group (n = 15) submitted to conventional physiotherapy. The intervention group (n = 19) received the same protocol plus additional aerobic exercise with cycle ergometer. Pulmonary function by spirometry, respiratory muscle strength by manovacuometry, and functional capacity through 6-minute walking test was assessed before surgery and at hospital discharge. RESULTS There was significant reduction in pulmonary function in both groups. In both groups, inspiratory muscle strength was maintained while expiratory muscle strength significantly decreased. Functional capacity was maintained in the intervention group (364.5 [324.5 to 428] vs. 348 [300.7 to 413.7] meters, P = .06), but it decreased significantly in control group patients (320 [288.5 to 393.0] vs. 292 [237.0 to 336.0] meters, P = .01). A significant difference in functional capacity was also found in intergroup analyses at hospital discharge (P = .03). CONCLUSION Aerobic exercise applied early on coronary artery bypass grafting patients may promote maintenance of functional capacity, with no impact on pulmonary function and respiratory muscle strength when compared with conventional physiotherapy.

Inspiratory Muscle Training and Functional Capacity in Patients Undergoing Cardiac Surgery

Introduction Cardiac surgery is a highly complex procedure which generates worsening of lung function and decreased inspiratory muscle strength. The inspiratory muscle training becomes effective for muscle strengthening and can improve functional capacity. Objective To investigate the effect of inspiratory muscle training on functional capacity submaximal and inspiratory muscle strength in patients undergoing cardiac surgery. Methods This is a clinical randomized controlled trial with patients undergoing cardiac surgery at Instituto Nobre de Cardiologia. Patients were divided into two groups: control group and training. Preoperatively, were assessed the maximum inspiratory pressure and the distance covered in a 6-minute walk test. From the third postoperative day, the control group was managed according to the routine of the unit while the training group underwent daily protocol of respiratory muscle training until the day of discharge. Results 50 patients, 27 (54%) males were included, with a mean age of 56.7±13.9 years. After the analysis, the training group had significant increase in maximum inspiratory pressure (69.5±14.9 vs. 83.1±19.1 cmH2O, P=0.0073) and 6-minute walk test (422.4±102.8 vs. 502.4±112.8 m, P=0.0031). Conclusion We conclude that inspiratory muscle training was effective in improving functional capacity submaximal and inspiratory muscle strength in this sample of patients undergoing cardiac surgery.

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.

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 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. 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.

Complicações pulmonares em crianças submetidas à cirurgia cardíaca em um hospital universitário

OBJECTIVE: To identify the prevalence of pulmonary complications in children undergone cardiac surgery, as well as demographic and clinical characteristics of this population. METHODS: The sample comprised 37 children of both genders, underwent cardiac surgery at the Hospital Universitario Presidente Dutra, Sao Luis (MA) during the year of 2007. There were not included patients who had lung disease in pre-operative period, patients with neurological disorders, intra-operative death besides lack of data in medical records. The data were obtained from general medical and nursing staff of their medical records. RESULTS: The population of the study was predominantly composed by female children, from the countryside and at school age. Pathologies considered low risk were the majority, especially the patent ductus arteriosus, interventricular communication and interatrial communication. It was observed that the largest share of children made use of cardiopulmonary bypass for more than 30 minutes, with a median of 80 minutes, suffered a median sternotomy, using only the mediastinal drain and made use of mechanical ventilation after surgery, with the median about 6.6 hours. Only three (8.1%) patients developed pulmonary complications, and of these, two died. CONCLUSION: Most of the sample was female, school aged and from the countryside. The low time of cardiopulmonary bypass and mechanical ventilation, and congenital heart disease with low risk, may have been factors that contributed to the low rate of pulmonary complications postoperative.

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 Brazils 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. Fishers 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.