Post-cardiotomy ECMO in pediatric and congenital heart surgery: impact of team training and equipment in the results

Introduction

Post-cardiotomy myocardial dysfunction requiring mechanical circulatory support occurs in about 0.5% of cases. In our environment, the use of extracorporeal membrane oxygenation has been increasing in recent years.

Objective

To evaluate the impact of investment in professional training and improvement of equipment in the rate of weaning from extracorporeal membrane oxygenation and survival.

Methods

A retrospective study. Fifty-six pediatric and/or congenital heart patients underwent post-cardiotomy extracorporeal membrane oxygenation at our institution between November 1999 and July 2014. We divided this period into two phases: phase I, 36 cases (before the structuring of the extracorporeal membrane oxygenation program) and phase II, 20 cases (after the extracorporeal membrane oxygenation program implementation) with investment in training and equipment). Were considered as primary outcomes: extracorporeal membrane oxygenation weaning and survival to hospital discharge. The results in both phases were compared using Chi-square test. To identify the impact of the different variables we used binary logistic regression analysis.

Results

Groups were comparable. In phase I, 9 patients (25%) were weaned from extracorporeal membrane oxygenation, but only 2 (5.5%) were discharged. In phase II, extracorporeal membrane oxygenation was used in 20 patients, weaning was possible in 17 (85%), with 9 (45%) hospital discharges (P<0.01). When the impact of several variables on discharge and weaning of extracorporeal membrane oxygenation was analyzed, we observe that phase II was an independent predictor of better results (P<0.001) and need for left cavities drainage was associated with worse survival (P=0.045).

Conclusion

The investment in professional training and improvement of equipment significantly increased extracorporeal membrane oxygenation results.     

Use of EuroSCORE as a predictor of morbidity after cardiac surgery

Objective

To evaluate the use of the EuroSCORE as a predictor of postoperative morbidity after cardiac surgery.

Methods

We retrospectively analyzed the charts of 900 patients operated on and admitted to the intensive care unit postoperatively at the Royal Portuguese Hospital of Recife. We included all patients with complete medical records, excluding those who died during surgery, underwent transplantation or correction of congenital heart disease. We evaluated the development of respiratory infection, cerebrovascular accident, and dialysis-dependent renal failure, and the EuroSCORE was compared in terms of the three complications using the Mann-Whitney test. The calibration model for predicting the morbidities being studied was evaluated using the test set of Homer-Lemeshow goodness. The accuracy of the model was assessed using the area under the ROC curve (AUROC).

Results

The model showed good calibration in predicting respiratory infection, acute renal failure and stroke (P=0.285, P=0.789, P=0.45, respectively), with good accuracy for respiratory infection (AUROC=0.710 and P<0.001) and dialysis-dependent renal failure (AUROC=0.834 and P<0.001), but no accuracy to predict stroke (AUROC=0.519). The high-risk patients were more likely to develop respiratory infection (OR=9.05, P<0.001) and dialysis-dependent renal failure (OR=39.6, P<0.001). The probability of developing respiratory infection and dialysis-dependent renal failure was less than 10% with EuroSCORE up to 7 and more than 70% with EuroSCORE greater than 15.

Conclusion

EuroSCORE proved to be a good predictor of major postoperative morbidity in cardiac surgery: respiratory and dialysis-dependent renal failure.     

Cardiac resynchronization therapy in patients with chronic Chagas cardiomyopathy: long-term follow up

Introduction

Chagas disease is a major cause of cardiomyopathy and sudden death in our country. It has a high mortality when their patients develop New York Heart Association (NYHA) class IV.

Objective

The objective of this study is to analyze the clinical outcome of patients with Chagas'' cardiomyopathy with congestive heart failure with optimized pharmacological therapy, undergoing cardiac resynchronization therapy.

Methods

Between January 2004 and February 2009, 72 patients with Chagas'' cardiomyopathy in NYHA class III and IV underwent cardiac resynchronization therapy and were monitored to assess their clinical evolution. We used the t test or the Wilcoxon test to compare the same variable in two different times. A P value < 0.05 was established as statistically significant.

Results

The average clinical follow-up was 46.6 months (range 4-79 months). At the end of the evaluation, 87.4% of patients were in NYHA class I or II (P<0.001). There was response to therapy in 65.3% of patients (P<0.001), with an overall mortality of 34.7%.

Conclusion

In patients with chronic Chagas cardiomyopathy undergoing cardiac resynchronization therapy, we found the following statistically significant changes: improvement in NYHA class and increase of left ventricle ejection fraction, a decrease of the systolic final diameter and systolic final left ventricle volume and improvement of patient survival.     

Predictors of stroke in patients undergoing cardiac surgery

Objective

To determine the risk factors related to the development of stroke in patients undergoing cardiac surgery.

Methods

A historical cohort study. We included 4626 patients aged > 18 years who underwent coronary artery bypass surgery, heart valve replacement surgery alone or heart valve surgery combined with coronary artery bypass grafting between January 1996 and December 2011. The relationship between risk predictors and stroke was assessed by logistic regression model with a significance level of 0.05.

Results

The incidence of stroke was 3% in the overall sample. After logistic regression, the following risk predictors for stroke were found: age 50-65 years (OR=2.11 - 95% CI 1.05-4.23 - P=0.036) and age >66 years (OR=3.22 - 95% CI 1.6-6.47 - P=0.001), urgent and emergency surgery (OR=2.03 - 95% CI 1.20-3.45 - P=0.008), aortic valve disease (OR=2.32 - 95% CI 1.18-4.56 - P=0.014), history of atrial fibrillation (OR=1.88 - 95% CI 1.05-3.34 - P=0.032), peripheral artery disease (OR=1.81 - 95% CI 1.13-2.92 - P=0.014), history of cerebrovascular disease (OR=3.42 - 95% CI 2.19-5.35 - P<0.001) and cardiopulmonary bypass time > 110 minutes (OR=1.71 - 95% CI 1.16-2.53 - P=0.007). Mortality was 31.9% in the stroke group and 8.5% in the control group (OR=5.06 - 95% CI 3.5-7.33 - P<0.001).

Conclusion

The study identified the following risk predictors for stroke after cardiac surgery: age, urgent and emergency surgery, aortic valve disease, history of atrial fibrillation, peripheral artery disease, history of cerebrovascular disease and cardiopulmonary bypass time > 110 minutes.     

Mitral annulus morphologic and functional analysis using real time tridimensional echocardiography in patients submitted to unsupported mitral valve repair

Introduction

Mitral valve repair is the treatment of choice to correct mitral insufficiency, although the literature related to mitral valve annulus behavior after mitral repair without use of prosthetic rings is scarce.

Objective

To analyze mitral annulus morphology and function using real time tridimensional echocardiography in individuals submitted to mitral valve repair with Double Teflon technique.

Methods

Fourteen patients with mitral valve insufficiency secondary to mixomatous degeneration that were submitted to mitral valve repair with the Double Teflon technique were included. Thirteen patients were in FC III/IV. Patients were evaluated in preoperative period, immediate postoperative period, 6 months and 1 year after mitral repair. Statistical analysis was made by repeated measures ANOVA test and was considered statistically significant P<0.05.

Results

There were no deaths, reoperation due to valve dysfunction, thromboembolism or endocarditis during the study. Posterior mitral annulus demonstrated a significant reduction in immediate postoperative period (P<0.001), remaining stable during the study, and presents a mean of reduction of 25.8% comparing with preoperative period. There was a significant reduction in anteroposterior and mediolateral diameters in the immediate postoperative period (P<0.001), although there was a significant increase in mediolateral diameter between immediate postoperative period and 1 year. There was no difference in mitral internal area variation over the cardiac cycle during the study.

Conclusion

Segmentar annuloplasty reduced the posterior component of mitral annulus, which remained stable in a 1-year-period. The variation in mitral annulus area during cardiac cycle remained stable during the study.     

Evaluation of the Society of Thoracic Surgeons score system for isolated coronary bypass graft surgery in a Brazilian population

Objective

Report the experience with the Society of Thoracic Surgeons scoring system in a Brazilian population submitted to isolated coronary artery bypass graft surgery.

Methods

Data were collected from January-2010 to December-2011, and analyzed to determine the performance of the Society of Thoracic Surgeons scoring system on the determination of postoperative mortality and morbidity, using the method of the receiver operating characteristic curve as well as the Hosmer-Lemeshow and the Chi-square goodness of fit tests. From the 1083 cardiac surgeries performed during the study period 659 represented coronary artery bypass graft procedures which are included in the present analysis. Mean age was 61.4 years and 77% were men.

Results

Goodness of fit tests have shown good calibration indexes both for mortality (X²=6.78, P=0.56) and general morbidity (X²=6.69, P=0.57). Analysis of area under the ROC-curve (AUC) demonstrated a good performance to detect the risk of death (AUC 0.76; P<0.001), renal failure (AUC 0.79; P<0.001), prolonged ventilation (AUC 0.80; P<0.001), reoperation (AUC 0.76; P<0.001) and major morbidity (AUC 0.75; P<0.001) which represents the combination of the assessed postoperative complications. STS scoring system did not present comparable results for short term hospital stay, prolonged length of hospital stay and could not be properly tested for stroke and wound infection.

Conclusion

Society of Thoracic Surgeons scoring system presented a good calibration and discrimination in our population to predict postoperative mortality and the majority of the harmful events following coronary artery bypass graft surgery. Analysis of larger samples might be needed to further validate the use of the score system in Brazilian populations.     

Fever During Rehabilitation in Patients With Traumatic Spinal Cord Injury: Analysis of 392 Cases From a National Rehabilitation Hospital in Turkey

Objective:

To determine the incidence and etiology of fever and the risk factors related to fever in adults with spinal cord injury (SCI) at the rehabilitation stage.

Design/Subjects:

A retrospective examination of records of 392 consecutive adult patients with traumatic SCI who received inpatient rehabilitation program.

Setting:

A national rehabilitation center in Turkey.

Outcome Measures:

Incidence and etiology of fever, period of hospitalization (days).

Results:

A total of 187 patients (47.7%) had fever at least once during their rehabilitation program. The most common etiology was urinary tract infection. The rate of fever occurrence was significantly higher in patients with complete SCI (P  =  0.001). In patients with fever, the use of an indwelling catheter was significantly higher compared with clean intermittent catheterization and spontaneous voiding (P  =  0.001). The hospitalization period of patients with fever was significantly longer than that of patients without fever (P  =  0.006).

Conclusions:

A high rate of fever was seen in patients with SCI during rehabilitation. Fever was caused by various infections, of which urinary tract infection was the most common. Patients with motor complete injuries and those with permanent catheters constituted higher risk groups. Fever prolonged the length of rehabilitation stay and hindered active participation in the rehabilitation program.     

EuroSCORE II and the importance of a local model,InsCor and the future SP-SCORE

Introduction

The most widely used model for predicting mortality in cardiac surgery was recently remodeled, but the doubts regarding its methodology and development have been reported.

Objective

The aim of this study was to assess the performance of the EuroSCORE II to predict mortality in patients undergoing coronary artery bypass grafts or valve surgery at our institution.

Methods

One thousand consecutive patients operated on coronary artery bypass grafts or valve surgery, between October 2008 and July 2009, were analyzed. The outcome of interest was in-hospital mortality. Calibration was performed by correlation between observed and expected mortality by Hosmer Lemeshow. Discrimination was calculated by the area under the ROC curve. The performance of the EuroSCORE II was compared with the EuroSCORE and InsCor (local model).

Results

In calibration, the Hosmer Lemeshow test was inappropriate for the EuroSCORE II (P=0.0003) and good for the EuroSCORE (P=0.593) and InsCor (P=0.184). However, the discrimination, the area under the ROC curve for EuroSCORE II was 0.81 [95% CI (0.76 to 0.85), P<0.001], for the EuroSCORE was 0.81 [95% CI (0.77 to 0.86), P<0.001] and for InsCor was 0.79 [95% CI (0.74-0.83), P<0.001] showing up properly for all.

Conclusion

The EuroSCORE II became more complex and resemblance to the international literature poorly calibrated to predict mortality in patients undergoing coronary artery bypass grafts or valve surgery at our institution. These data emphasize the importance of the local model.     

Impact of type of procedure and surgeon on EuroSCORE operative risk validation

Objective

EuroSCORE has been used in cardiac surgery operative risk assessment, despite important variables were not included. The objective of this study was to validate EuroSCORE on mortality prediction in a Brazilian cardiovascular surgery center, defining the influence of type of procedure and surgical team.

Methods

Between January 2006 and June 2011, 2320 consecutive adult patients were studied. According to additive EuroSCORE, patients were divided into low risk (score<2), medium risk (3 - 5), high risk (6 - 11) and very high risk (>12). The relation between observed mortality (O) and expected mortality (E) according to logistic EuroSCORE was calculated for each of the groups, types of procedures and surgeons with > 150 operations, and analyzed by logistic regression.

Results

EuroSCORE correlated to the observed mortality (O/E=0.94; P<0.0001; area under the curve 0.78). However, it overestimated the mortality in very high risk patients (O/E=0.74; P=0.001). EuroSCORE tended to overestimate isolated myocardial revascularization mortality (O/E=0.81; P=0.0001) and valve surgery mortality (O/E=0.89; P=0.007) and it tended to underestimate combined procedures mortality (O/E=1.09; P<0.0001). EuroSCORE overestimated surgeon A mortality (O/E=0.46; P<0.0001) and underestimated surgeon B mortality (O/E=1.3; P<0.0001), in every risk category.

Conclusion

In the present population, EuroSCORE overestimates mortality in very high risk patients, being influenced by type of procedure and surgical team. The most appropriate surgical team may minimize risks imposed by preoperative profiles.     

Evaluation of the influence of pulmonary hypertension in ultra-fast-track anesthesia technique in adult patients undergoing cardiac surgery

Objective

To evaluate the influence of pulmonary hypertension in the ultra-fast-track anesthesia technique in adult cardiac surgery.

Methods

A retrospective study. They were included 40 patients divided into two groups: GI (without pulmonary hypertension) and GII (with pulmonary hypertension). Based on data obtained by transthoracic echocardiography. We considered as the absence of pulmonary hypertension: a pulmonary artery systolic pressure (sPAP) <36 mmHg, with tricuspid regurgitation velocity <2.8 m/s and no additional echocardiographic signs of PH, and PH as presence: a sPAP >40 mmHg associated with additional echocardiographic signs of PH. It was established as influence of pulmonary hypertension: the impossibility of extubation in the operating room, the increase in the time interval for extubation and reintubation the first 24 hours postoperatively. Univariate and multivariate analyzes were performed when necessary. Considered significant a P value <0.05.

Results

The GI was composed of 21 patients and GII for 19. All patients (100%) were extubated in the operating room in a medium time interval of 17.58±8.06 min with a median of 18 min in GII and 17 min in GI. PH did not increase the time interval for extubation (P=0.397). It required reintubation of 2 patients in GII (5% of the total), without statistically significant as compared to GI (P=0.488).

Conclusion

In this study, pulmonary hypertension did not influence on ultra-fast-track anesthesia in adult cardiac surgery.     

Effects of intraoperative diltiazem infusion on flow changes in arterial and venous grafts in coronary artery bypass graft surgery

Objective

This study aimed to show the effects of intra-operative diltiazem infusion on flow in arterial and venous grafts in coronary artery bypass graft surgery.

Methods

Hundred fourty patients with a total of 361 grafts [205 (57%) arterial and 156 (43%) venous] underwent isolated coronary surgery. All the grafts were measured by intraoperative transit time flow meter intra-operatively. Group A (n=70) consisted of patients who received diltiazem infusion (dose of 2.5 microgram/kg/min), and Group B (n=70) didn''t receive diltiazem infusion.

Results

Mean graft flow values of left internal mammary artery were 53 ml/min in Group A and 40 ml/min in Group B (P<0.001). Pulsatility index (PI) values of left internal mammary artery for Group A and Group B were 2.6 and 3.0 respectively (P<0.001). No statistically significant difference was found between venous graft parameters.

Conclusion

We recommend an effect of diltiazem infusion in increasing graft flows in coronary artery bypass graft operations.     

Management of multivessel coronary disease after primary angioplasty: staged reintervention versus optimized clinical treatment and two-year follow-up

Objective

In the clinical scenario of ST-segment elevation acute myocardial infarction, several patients with multivessel coronary atherosclerotic disease are discharged without a defined strategy to monitor the residual atherosclerotic lesions. The clinical endpoints evaluated were cardiovascular death, symptoms of angina pectoris, rehospitalization for a new acute coronary syndrome, and the necessity of reintervention during the two-year follow-up.

Methods

This observational, prospective, and historical study included multivessel coronary atherosclerotic disease patients who were admitted to a tertiary care university hospital with ST-segment elevation acute myocardial infarction and underwent primary percutaneous coronary intervention with stent implantation only at the culprit lesion site; these patients were monitored in the outpatient clinic according to two treatments: the Clinical Group - CG (optimized pharmacological therapy associated with counseling for a healthy diet and cardiac rehabilitation) or the Intervention Group - IG (new staged percutaneous coronary intervention or surgical coronary artery bypass graft surgery combined with the previously prescribed treatment).

Results

Of 143 patients consecutively admitted with ST-segment elevation acute myocardial infarction, 57 were eligible for the study (CG=44 and IG=13). Regarding the clinical endpoints, the cardiovascular death rate did not differ between the CG and IG. The symptom of angina pectoris and the rehospitalization rate for a new episode of acute coronary syndrome were accentuated in the CG (P=0.020 and P=0.049, respectively) mainly in individuals with evidence of ischemia evidenced by myocardial scintigraphy (P<0.001 and P=0.001, respectively) which culminated in an even greater need for reintervention (P=0.001) in this subgroup of patients.

Conclusion

The staged intervention was demonstrated to be safe and able to reduce angina pectoris and rehospitalization for a new episode of acute coronary syndrome. In addition, it decreases the likelihood of unplanned reinterventions of patients without ischemia evidenced by myocardial scintigraphy.     

Impact of respiratory infection in the results of cardiac surgery in a tertiary hospital in Brazil

Objective

To assess the impact of respiratory tract infection in the postoperative period of cardiac surgery in relation to mortality and to identify patients at higher risk of developing this complication.

Methods

Cross-sectional observational study conducted at the Recovery of Cardiothoracic Surgery, using information from a database consisting of a total of 900 patients operated on in this hospital during the period from 01/07/2008 to 1/07/2009. We included patients whose medical records contained all the information required and undergoing elective surgery, totaling 109 patients with two excluded. Patients were divided into two groups, WITH and WITHOUT respiratory tract infection, as the development or respiratory tract infection in hospital, with patients in the group without respiratory tract infection, the result of randomization, using for the pairing of the groups the type of surgery performed. The outcome variables assessed were mortality, length of hospital stay and length of stay in intensive care unit. The means of quantitative variables were compared using the Wilcoxon and student t-test.

Results

The groups were similar (average age P=0.17; sex P=0.94; surgery performed P=0.85-1.00) Mortality in the WITH respiratory tract infection group was significantly higher (P<0.0001). The times of hospitalization and intensive care unit were significantly higher in respiratory tract infection (P<0.0001). The presence of respiratory tract infection was associated with the development of other complications such as renal failure dialysis and stroke P<0.00001 and P=0.002 respectively.

Conclusion

The development of respiratory tract infection postoperative cardiac surgery is related to higher mortality, longer periods of hospitalization and intensive care unit stay.     

Predictors of mortality in cardiac surgery: brain natriuretic peptide type B

Objective

We evaluated whether the preoperative serum concentration of brain natriuretic peptide (BNP) is a predictor of in-hospital mortality in patients that underwent cardiac surgery.

Methods

We continuously evaluated 488 patients that underwent cardiac valve surgery or coronary artery bypass grafting (CABG) between January of 2009 and July of 2012. Follow up of these patients were done prospectively for 30 days postoperatively.

Results

Data analysis showed that the overall mortality rate was equal to 9.6%, Receiver Operating Charactheristic (ROC) curve analysis found the optimal cut-off value of BNP equal to 382 pg/mL for overall mortality (AUC=0.73, 95% CI=0.66 to 0.81, P<0.001). Multivariate analysis showed that the value of BNP higher than 382 pg/mL (P=0.033, HR=2.05, 95% CI=1.6 to 3.98) was an independent predictor of overall mortality at 30 days postoperatively.

Conclusion

We concluded that the preoperative serum concentration of BNP is an independent predictor of mortality in patients undergoing valve surgery or coronary artery bypass graft.     

Incidence of stroke and acute renal failure in patients of postoperative atrial fibrillation after myocardial revascularization

Introduction

Postoperative atrial fibrillation is the most common arrhythmia in cardiac surgery, its incidence range between 20% and 40%.

Objective

Quantify the occurrence of stroke and acute renal insufficiency after myocardial revascularization surgery in patients who had atrial fibrillation postoperatively.

Methods

Cohort longitudinal bidirectional study, performed at Portuguese Beneficent Hospital (SP), with medical chart survey of patients undergoing myocardial revascularization surgery between June 2009 to July 2010. From a total of 3010 patients were weaned 382 patients that presented atrial fibrillation preoperatively and/or associated surgeries. The study was conducted in accordance with national and international following resolutions: ICH Harmonized Tripartite Guidelines for Good Clinical Practice - 1996; CNS196/96 Resolution, and Declaration of Helsinki.

Results

The 2628 patients included in this study were divided into two groups: Group I, who didn''t show postoperative atrial fibrillation, with 2302 (87.6%) patients; and group II, with 326 (12.4%) who developed postoperative atrial fibrillation. The incidence of stroke in patients was 1.1% without postoperative atrial fibrillation vs. 4% with postoperative atrial fibrillation (P<0.001). Postoperative acute renal failure was observed in 12% of patients with postoperative atrial fibrillation and 2.4% in the group without postoperative atrial fibrillation (P<0.001), that is a relation 5 times greater.

Conclusion

In this study there was a high incidence of stroke and acute renal failure in patients with postoperative atrial fibrillation, with rates higher than those reported in the literature.     

Mortality risk is dose-dependent on the number of packed red blood cell transfused after coronary artery bypass graft

Introduction

Transfusions of one or more packed red blood cells is a widely strategy used in cardiac surgery, even after several evidences of increased morbidity and mortality. The world''s blood shortage is also already evident.

Objective

To assess whether the risk of mortality is dose-de>pendent on the number of packed red blood cells transfused after coronary artery bypass graft.

Methods

Between June 2009 and July 2010, were analyzed 3010 patients: transfused and non-transfused. Transfused patients were divided into six groups according to the number of packed red blood cells received: one, two, three, four, five, six or more units, then we assess the mortality risk in each group after a year of coronary artery bypass graft. To calculate the odds ratio was used the multivariate logistic regression model.

Results

The increasing number of allogeneic packed red blood cells transfused results in an increasing risk of mortality, highlighting a dose-dependent relation. The odds ratio values increase with the increased number of packed red blood cells transfused. The death''s gross odds ratio was 1.42 (P=0.165), 1.94 (P=0.005), 4.17; 4.22, 8.70, 33.33 (P<0.001) and the adjusted death''s odds ratio was 1.22 (P=0.43), 1.52 (P=0.08); 2.85; 2.86; 4.91 and 17.61 (P<0.001), as they received one, two, three, four, five, six or more packed red blood cells, respectively.

Conclusion

The mortality risk is directly proportional to the number of packed red blood cells transfused in coronary artery bypass graft. The greater the amount of allogeneic blood transfused the greater the risk of mortality. The current transfusion practice needs to be reevaluated.     

Chronic stress and coping among cardiac surgeons: a single center study

Introduction

Cardiac surgeons stress may impair their quality of life and professional practice.

Objective

To assess perceived chronic stress and coping strategies among cardiac surgeons.

Methods

Twenty-two cardiac surgeons answered two self-assessment questionnaires, the Trier Inventory for Chronic Stress and the German SGV for coping strategies.

Results

Participants mean age was 40±14.1 years and 13 were male; eight were senior physicians and 14 were residents. Mean values for the Trier Inventory for Chronic Stress were within the normal range. Unexperienced physicians had significantly higher levels of dissatisfaction at work, lack of social recognition, and isolation (P<0.05). Coping strategies such as play down, distraction from situation, and substitutional satisfaction were also significantly more frequent among unexperienced surgeons. "Negative" stress-coping strategies occur more often in experienced than in younger colleagues (P=0.029). Female surgeons felt more exposed to overwork (P=0.04) and social stress (P=0.03).

Conclusion

Cardiac surgeons show a tendency to high perception of chronic stress phenomena and vulnerability for negative coping strategies.     

Pre-operative inspiratory muscle training preserves postoperative inspiratory muscle strength following major abdominal surgery �C a randomised pilot study

INTRODUCTION

The aim of this pilot study was to assess the effect of pre-operative inspiratory muscle training (IMT) on respiratory variables in patients undergoing major abdominal surgery.

PATIENTS AND METHODS

Respiratory muscle strength (maximum inspiratory [MIP] and expiratory [MEP] mouth pressure) and pulmonary functions were measured at least 2 weeks before surgery in 80 patients awaiting major abdominal surgery. Patients were then allocated randomly to one of four groups (Group A, control; Group B, deep breathing exercises; Group C, incentive spirometry; Group D, specific IMT). Patients in groups B, C and D were asked to train twice daily, each session lasting 15 min, for at least 2 weeks up to the day before surgery. Outcome measurements were made immediately pre-operatively and postop-eratively.

RESULTS

In groups A, B and C, MIP did not increase from baseline to pre-operative assessments. In group D, MIP increased from 51.5 cmH₂O (median) pre-training to 68.5 cmH₂O (median) post-training pre-operatively (P < 0.01). Postoperatively, groups A, B and C showed a fall in MIP from baseline (P < 0.01, P < 0.01) and P = 0.06, respectively). No such significant reduction in postoperative MIP was seen in group D (P = 0.36).

CONCLUSIONS

Pre-operative specific IMT improves MIP pre-operatively and preserves it postoperatively. Further studies are required to establish if this is associated with reduced pulmonary complications.     

Stratification of complexity in congenital heart surgery: comparative study of the Risk Adjustment for Congenital Heart Surgery (RACHS-1) method, Aristotle basic score and Society of Thoracic Surgeons-European Association for Cardio- Thoracic Surgery (STS-EACTS) mortality score

Objective

To determine whether stratification of complexity models in congenital heart surgery (RACHS-1, Aristotle basic score and STS-EACTS mortality score) fit to our center and determine the best method of discriminating hospital mortality.

Methods

Surgical procedures in congenital heart diseases in patients under 18 years of age were allocated to the categories proposed by the stratification of complexity methods currently available. The outcome hospital mortality was calculated for each category from the three models. Statistical analysis was performed to verify whether the categories presented different mortalities. The discriminatory ability of the models was determined by calculating the area under the ROC curve and a comparison between the curves of the three models was performed.

Results

360 patients were allocated according to the three methods. There was a statistically significant difference between the mortality categories: RACHS-1 (1) - 1.3%, (2) - 11.4%, (3)-27.3%, (4) - 50 %, (P<0.001); Aristotle basic score (1) - 1.1%, (2) - 12.2%, (3) - 34%, (4) - 64.7%, (P<0.001); and STS-EACTS mortality score (1) - 5.5 %, (2) - 13.6%, (3) - 18.7%, (4) - 35.8%, (P<0.001). The three models had similar accuracy by calculating the area under the ROC curve: RACHS-1- 0.738; STS-EACTS-0.739; Aristotle- 0.766.

Conclusion

The three models of stratification of complexity currently available in the literature are useful with different mortalities between the proposed categories with similar discriminatory capacity for hospital mortality.     

Development of cardioplegic solution without potassium: experimental study in rat

Introduction

Myocardial preservation during open heart surgeries and harvesting for transplant are of great importance. The heart at the end of procedure has to resume its functions as soon as possible. All cardioplegic solutions are based on potassium for induction of cardioplegic arrest.

Objective

To assess a cardioplegic solution with no potassium addition to the formula with two other commercially available cardioplegic solutions. The comparative assessment was based on cytotoxicity, adenosine triphosphate myocardial preservation, and caspase 3 activity. The tested solution (LIRM) uses low doses of sodium channel blocker (lidocaine), potassium channel opener (cromakalin), and actin/myosin cross bridge inhibitor (2,3-butanedione monoxime).

Methods

Wistar rats underwent thoracotomy under mechanical ventilation and three different solutions were used for "in situ" perfusion for cardioplegic arrest induction: Custodiol (HTK), Braile (G/A), and LIRM solutions. After cardiac arrest, the hearts were excised and kept in cold storage for 4 hours. After this period, the hearts were assessed with optical light microscopy, myocardial ATP content and caspase 3 activity. All three solutions were evaluated for direct cytotoxicity with L929 and WEHI-164 cells.

Results

The ATP content was higher in the Custodiol group compared to two other solutions (P<0.05). The caspase activity was lower in the HTK group compared to LIRM and G/A solutions (P<0.01). The LIRM solution showed lower caspase activity compared to Braile solution (P<0.01). All solutions showed no cytotoxicity effect after 24 hours of cells exposure to cardioplegic solutions.

Conclusion

Cardioplegia solutions without potassium are promised and aminoacid addition might be an interesting strategy. More evaluation is necessary for an optimal cardioplegic solution development.