Nuria Novoa

Postoperative chest tube management: measuring air leak using an electronic device decreases variability in the clinical practice

OBJECTIVES Since there are no data in the literature regarding variability in the management of postoperative pleural drainages, we have designed a prospective randomized study aimed at measuring inter-observer variability in deciding when to withdraw chest tubes after lung resection and to evaluate if the use of an electronic device to measure postoperative air leak decreases clinical practice variations. METHODS Sixty-one patients undergoing pulmonary resection were randomly assigned to one of the following groups: digital group (electronic measure of pleural air leak using Millicore AB DigiVent chest drainage system) or traditional group (standard water seal pleural chamber). Chest tube withdrawal criteria were established in advance. During morning rounds, two thoracic surgeons with comparable clinical experience and blinded to the decision of their counterpart, evaluated chest tube withdrawal criteria and noted whether the tube should be withdrawn or not. Inter-observer variability kappa index and global, positive, and negative agreement rates were calculated on 2 x 2 tables. Each observation episode was considered in the calculation. RESULTS Fifty-four observations were recorded in the traditional group. Kappa coefficient was 0.37 (overall agreement rate: 0.58; positive agreement rate: 0.72; and negative agreement rate: 0.64). In the digital group, 67 observations were recorded. Kappa coefficient was 0.88 (overall agreement rate: 0.94; positive agreement rate 0.94; and negative agreement rate 0.94). CONCLUSIONS We have demonstrated a high rate of disagreement related to the indication to remove chest tubes after lung resection and the improvement of the agreement rate with the use of an electronic device to measure postoperative air leak and pleural pressures.

Recalibration of the Revised Cardiac Risk Index in Lung Resection Candidates

BACKGROUND The revised cardiac risk index (RCRI) has been proposed as a tool for cardiac risk stratification before lung resection. However, the RCRI was originally developed from a generic surgical population including a small group of thoracic patients. The objective of this study was to recalibrate the RCRI in candidates for major lung resections to provide a more specific instrument for cardiac risk stratification. METHODS One thousand six hundred ninety-six patients who underwent lobectomy (1,426) or pneumonectomy (270) in two centers between the years of 2000 and 2008 were analyzed. Stepwise logistic regression and bootstrap analyses were used to recalibrate the six variables comprising the RCRI. The outcome variable was occurrence of major cardiac complications (cardiac arrest, complete heart block, acute myocardial infarction, pulmonary edema, or cardiac death during admission). Only those variables with a probability of less than 0.1 in more than 50% of bootstrap samples were retained in the final model and proportionally weighted according to their regression estimates. RESULTS The incidence of major cardiac morbidity was 3.3% (57 patients). Four of the six variables present in the RCRI were reliably associated with major cardiac complications: cerebrovascular disease (1.5 points), cardiac ischemia (1.5 points), renal disease (1 point), and pneumonectomy (1.5 points). Patients were grouped into four classes according to their recalibrated RCRI, predicting an incremental risk of cardiac morbidity (p < 0.0001). Compared with the traditional RCRI, the recalibrated score had a higher discrimination (c indexes, 0.72 versus 0.62; p = 0.004). CONCLUSIONS The recalibrated RCRI can be reliably used as a first-line screening instrument during cardiologic risk stratification for selecting those patients needing further cardiologic testing from those who can proceed with pulmonary evaluation without any further cardiac tests.

Prediction of postoperative morbidity after lung resection using an artificial neural network ensemble

OBJECTIVE To propose an ensemble model of artificial neural networks (ANNs) to predict cardio-respiratory morbidity after pulmonary resection for non-small cell lung cancer (NSCLC). METHODS Prospective clinical study was based on 489 NSCLC operated cases. An artificial neural network ensemble was developed using a training set of 348 patients undergoing lung resection between 1994 and 1999. Predictive variables used were: sex of the patient, age, body mass index, ischemic heart disease, cardiac arrhythmia, diabetes mellitus, induction chemotherapy, extent of resection, chest wall resection, perioperative blood transfusion, tumour staging, forced expiratory volume in 1s percent (FEV(1)%), and predicted postoperative FEV(1)% (ppoFEV(1)%). The analysed outcome was the occurrence of postoperative cardio-respiratory complications prospectively recorded and codified. The artificial neural network ensemble consists of 100 backpropagation networks combined via a simple averaging method. The probabilities of complication calculated by ensemble model were obtained to the actual occurrence of complications in 141 cases operated on between January 2000 and December 2001 and a receiver operating characteristic (ROC) curve for this method was constructed. RESULTS The prevalence of cardio-respiratory morbidity was 0.25 in the training and 0.30 in the validation series. The accuracy for morbidity prediction (area under the ROC curve) was 0.98 by the ensemble model. CONCLUSION In this series an artificial neural network ensemble offered a high performance to predict postoperative cardio-respiratory morbidity.

Influence of major pulmonary resection on postoperative daily ambulatory activity of the patients

To describe and compare the daily ambulatory activity of the patients before and one month after major lung resection. Daily activity was measured using a pedometer (OMROM Walking Style PRO) given preoperatively in a prospective way to a series of 21 consecutive cases scheduled for lobectomy or pneumonectomy. Analyzed variables were age, pulmonary function, mean number of total and aerobic steps per day, walked distance and mean daily time of aerobic activity. Activity variables were analyzed individually and as a new differential variable DELTA. Wilcoxon and Mann-Whitney nonparametric tests were used for comparison between groups. General series data: 19 male. Age: 63+/-10.9 years. FEV(1)%: 88.4+/-22.7. DLCO: 86.2+/-21.6. Eleven cases had COPD criteria. Type of surgery: 3 pneumonectomy/18 lobectomy. Activity data: all patients showed a global decrease of their activity one month after surgery but, patients in the pneumonectomy group are unable to keep aerobic activity meanwhile patients that undergone lobectomy showed only a 25% reduction in the measured variables. Major pulmonary resection decreases the time and the quality of the daily ambulatory activity of the patients during the first postoperative month. Despite limitations, the chosen pedometer OMRON Walking Style Pro is an efficient tool to evaluate the perioperative daily ambulatory activity of patients.

Utility of standardized exercise oximetry to predict cardiopulmonary morbidity after lung resection

OBJECTIVES To evaluate if desaturation, measured by finger oximetry on standardized exercise, accurately predicts cardiopulmonary morbidity after pulmonary resection. METHODS A prospective observational clinical study was carried out on 81 consecutive lung carcinoma patients scheduled for pulmonary resection from February 1998 to March 1999. Finger oximetry was monitored during an incremental to exhaustion cycle exercise test. The presence or absence of desaturation (cut-off value 90%) during exercise was recorded. Other independent analyzed variables were: age of the patient (over 75th percentile), body-mass index (BMI) (over 75th percentile), presence of major cardiovascular co-morbidity, and calculated postoperative FEV1% (under 25th percentile) according to the number of resected segments (ppoFEV1%). Postoperative cardiopulmonary morbidity was the evaluated dependent outcome. Fishers exact test and risk calculation on contingency tables were used for statistical analysis. RESULTS A lobectomy was performed in 62 cases, a pneumonectomy was performed in 16 cases, and a segmentectomy was performed in three cases. The mean age of the patients was 63.6 years (SD 10.3, range 34-79 years, 75th percentile 72 years), the mean BMI was 25.9 (SD 4.9, range 16.9-38.1, 75th percentile 29.3), and the mean ppoFEV1% was 64.1 (SD 2016.1, range 29.5-98.6, 25th percentile 50.5). In 14 patients exercise desaturation was registered. Postoperative cardiopulmonary morbidity was presented in 32 cases (five deaths). No correlation was found between postoperative morbidity and any of the following variables: age of the patient, BMI, and co-morbidity. On univariate analysis only low ppoFEV1% (P<0.001) was associated with the outcome, so no multivariate analysis has been carried out. CONCLUSIONS We have shown that desaturation during standardized exercise in this series adds no relevant information to predict postoperative cardiorespiratory morbidity after lung resection.

Morbidity after surgery for non-small cell lung carcinoma is not related to neoadjuvant chemotherapy

OBJECTIVES To compare postoperative morbidity and mortality rates in two groups of operated non-small cell lung carcinoma patients (NSCLC) with or without induction chemotherapy. METHODS This is a case-control study on 42 cases and 42 controls. Cases (Group A) underwent induction chemotherapy. Chemotherapy indications and regimens were variable. Control cases (Group B) were randomly selected among 494 NSCLC comparable patients operated on in the same period of time. The selection criteria for operation were the same in both groups. Dependent outcomes were operative death and complications. Independent selected variables were: age, co-morbidity, predicted postoperative FEV1% (1 s forced expiratory volume in percentage), type of surgery and clinical and pathological staging. All postoperative events and independent variables were prospectively registered. Chi-square and risk calculations on contingence tables and one-way ANOVA have been tested. RESULTS Both series are comparable in demographics, preoperative variables and type of surgery. No mortality has been registered. In Group A, the overall morbidity was 26.2% (11 out of 42 cases), and in Group B, this was 42.9% (18 out of 42 cases; P=0.084). Morbidity was not related to the type of surgery (pneumonectomy vs. other; P=0.205 in Group A and P=0.08 in Group B). Pathological staging did not influence the postoperative outcome, either in Group A (P=0.72; odds ratio, 1.515; 95% confidence interval (CI), 0.375-6.122) or Group B (P=0.299; odds ratio, 0.4; 95% CI, 0.089-1.797). CONCLUSIONS Induction chemotherapy in NSCLC has no influence on postoperative morbidity.

Análisis descriptivo de una serie de casos diagnosticados de mediastinitis aguda

La mediastinitis aguda es una de las enfermedades toracicas mas agresivas. La mortalidad varia entre el 14 y el 42%. Nuestro objetivo es presentar un analisis retrospectivo de una serie de 26 casos (20 varones y 6 mujeres) tratados entre enero de 1994 y marzo de 2002 y una revision de la bibliografia. La mediastinitis fue de origen esofagico en 17 pacientes (8 posquirurgicas, 4 por rotura iatrogenica, 4 por rotura no iatrogenica y una por cuerpo extrano), de origen bucofaringeo en 6 pacientes y secundarias a esternotomia media en 3. Se trato quirurgicamente a 25 pacientes; ademas del desbridamiento radical y los drenajes, que se hicieron en todos los pacientes, en 10 se practico una esofaguectomia o reseccion de plastia gastrica; en 5, suturas primarias de esofago; en uno, plastia de pectoral mayor, y en otro, esternectomia mas omentoplastia. Cuatro pacientes fallecieron en los 30 dias despues de la intervencion (15,4%). La mortalidad en nuestro entorno es similar a la descrita en la bibliografia. Los resultados justifican el tratamiento agresivo y temprano.

Chest Physiotherapy in Lung Resection Patients: State of the Art

The role of chest physiotherapy in limiting postoperative pulmonary complications and in the recovery of pulmonary function and exercise capacity after lung surgery is still unclear because of the lack of conclusive, well-designed clinical trials. In this article the available literature on these topics is reviewed, and the effects of respiratory physiotherapy, instituted preoperatively or administered after surgery to patients undergoing lung resection, are commented on. The authors conclude that chest physiotherapy improves preoperative exercise capacity; this is a parameter highly predictive of postoperative pulmonary complications. Also physiotherapy administered during the immediate period after lung resection probably decreases frequency of pulmonary complications. Finally, further investigation is required for a better understanding of the effects of long-term chest physiotherapy after hospital discharge in lung resection patients.

The risk of death due to cardiorespiratory causes increases with time after right pneumonectomy: a propensity score-matched analysis †

OBJECTIVES The study aimed to compare in-hospital, 30-day and non-cancer-related 6-month death rates in a series of right and left pneumonectomy cases matched according to functional parameters. METHODS A retrospective study was conducted on a series of 263 non-small cell lung cancer patients who underwent pneumonectomy. Left and right pneumonectomy cases were matched according to propensity scores using the following variables: age, coronary artery disease, any other cardiac comorbidity and predicted postoperative forced expiratory volume in the 1st second (ppoFEV1). After matching, 89 pairs of cases were selected. In-hospital, 30-day and 6-month crude and risk-adjusted death rates not related to cancer relapse or distant metastases were calculated for right and left pneumonectomy and compared on 2-by-2 tables using odds ratios. Death hazards were estimated by Cox regression, introducing the following independent variables in the model: age, cardiac comorbidity, ppoFEV1 and occurrence of any postoperative cardiorespiratory complication or bronchial fistula. RESULTS Non-cancer-related in-hospital, 30-day and 6-month death rates were, respectively, 8.4 (3.4 in left and 13.5 in right cases; P = 0.015), 11.8 (7.8 in left and 15.7 in right cases; P = 0.10) and 18.5% (12.4 in left and 24.7 in right cases; P = 0.033). On Cox regression, age, right pneumonectomy and the occurrence of postoperative cardiorespiratory complications (but not bronchial fistula) were related to the risk of death at 6 months. CONCLUSIONS The risk of death after pneumonectomy increases with time and strongly depends on the side of the operation (it is higher after right pneumonectomy) and on the occurrence of any postoperative cardiorespiratory complication. Neither hospital nor 30-day mortality should be reported as a valid outcome after pneumonectomy since they do not represent the real risk of the operation.

The values of intrapleural pressure before the removal of chest tube in non-complicated pulmonary lobectomies.

OBJECTIVES Digitalized chest drainage systems allow for quantification of air leak and measurement of intrapleural pressure. Little is known about the value of intrapleural pressure during the postoperative phase and its role in the recovering process after pulmonary resection. The objective of this investigation was to measure the values of pleural pressure immediately before the removal of chest tube after different types of pulmonary lobectomy. METHODS Prospective observational analysis on 203 consecutive patients submitted to pulmonary lobectomy during a 12-month period at two centres. Multiple measurements were recorded in the last hour before the removal of chest tube and averaged for the analysis. All patients were seated in bed in a 45° up-right position or in a chair, had a single chest tube and were not connected to suction during the evaluation period. Analysis of variance (ANOVA) was used to assess the differences in pleural pressure between different types of lobectomies. RESULTS The average maximum, minimum and differential pressures were -6.1, -19.5 and 13.3 cmH(2)O, respectively. The average pressures were similar in all types of lobectomies (ANOVA, P = 0.2) and ranged from -11 to -13 cmH(2)O, with the exception of right upper bilobectomy (-20 cmH(2)O, all P-values vs. other types of lobectomies <0.05). Similar values were also recorded for maximum pressures (range -4.4 to -8.4 cmH(2)O) and minimum pressures (-31.6 cmH(2)O vs. ranged from -15.4 to -20.5 cmH(2)O, all P-values <0.01). The average pleural pressure was not associated with FEV1 (P = 0.9), DLCO (P = 0.2) or FEV1/FVC ratio (P = 0.6), when tested with linear regression. Similarly, the average pleural pressure was similar in patients with and without COPD (-12.1 vs. -13.0 cmH(2)O, P = 0.4). The ANOVA test was used to assess differences in pressures between different lobectomies. CONCLUSIONS The so-called water seal status may actually correspond to intrapleural pressures ranging from -13 to -20 cmH(2)O. Modern electronic chest drainage devices allow a stable control of the intrapleural pressure. Thus, the values found in this study may be used as target pressures for different types of lobectomies, in order to favour lung recovery after surgery.