Risk factor analysis for postoperative acute respiratory distress syndrome and early mortality after pneumonectomy: the predictive value of preoperative lung perfusion distribution

Salvage treatment of acute respiratory failure after autogenous tissue flap transplantation for chronic empyema with chest wall sinus: a case report and literature review

BACKGROUND

Chronic empyema with chest wall sinus is a difficult and complex disease caused by multiple causative factors. It is difficult to control local infection due to its possible combination of bronchopleural fistula (BPF) and residual bone.The relevant literature emphasizes some risk factors for empyema progression after pneumonectomy, while the correlation between empyema and BPF after pneumonectomy increases mortality by infecting the remaining lungs. After pneumonectomy, the lung function of the contralateral side is particularly important.

CASE PRESENTATION

This paper reports a 62-year-old male patient who underwent right pneumonectomy for squamous cell carcinoma of the lung 12 years ago and began to develop empyema with anterior chest wall sinus 3 years ago. After admission, chest computed tomography (CT) showed right pleural effusion and formation of chest wall sinus. According to his clinical symptoms and imaging examination, he was diagnosed as chronic empyema with chest wall sinus.Due to the huge residual cavity of the patient,the clinical effect of using free vastus lateralis myocutaneous flap combined with pedicled pectoralis major muscle flap to fill the abscess cavity was satisfactory,but acute respiratory failure occurred due to left lung aspiration pneumonia after operation.

CONCLUSIONS

After a series of treatment measures such as tracheal cannula, tracheotomy, anti-infection, maintenance of circulatory stability, and rehabilitation training, the patient was ultimately rescued and cured. Postoperative follow-up showed that the muscle flaps survived and empyema was eliminated.

ARDS after Pneumonectomy: How to Prevent It? Development of a Nomogram to Predict the Risk of ARDS after Pneumonectomy for Lung Cancer

(1) Background: The cause of ARDS after pneumonectomy is still unclear, and the study of risk factors is a subject of debate. (2) Methods: We reviewed a large panel of pre-, peri- and postoperative data of 211 patients who underwent pneumonectomy during the period 2014−2021. Univariable and multivariable logistic regression was used to quantify the association between preoperative parameters and the risk of developing ARDS, in addition to odds ratios and their respective 95% confidence intervals. A backward stepwise selection approach was used to limit the number of variables in the final multivariable model to significant independent predictors of ARDS. A nomogram was constructed based on the results of the final multivariable model, making it possible to estimate the probability of developing ARDS. Statistical significance was defined by a two-tailed p-value < 0.05. (3) Results: Out of 211 patients (13.3%), 28 developed ARDS. In the univariate analysis, increasing age, Charlson Comorbidity Index and ASA scores, DLCO < 75% predicted, preoperative C-reactive protein (CRP), lung perfusion and duration of surgery were associated with ARDS; a significant increase in ARDS was also observed with decreasing VO2max level. Multivariable analysis confirmed the role of ASA score, DLCO < 75% predicted, preoperative C-reactive protein and lung perfusion. Using the nomogram, we classified patients into four classes with rates of ARDS ranking from 2.0% to 34.0%. (4) Conclusions: Classification in four classes of growing risk allows a correct preoperative stratification of these patients in order to quantify the postoperative risk of ARDS and facilitate their global management.

[The role of the intensive care unit after thoracic surgery]

Lung (bronchial) cancer is the leading cause of cancer-related death in Western countries today. Thoracic surgery represents a major therapeutic strategy and the various advances made in recent years have made it possible to develop less and less invasive techniques. That said, the postoperative period may be lengthy, post-surgical approaches need to be more precisely codified, and it matters that the different interventions involved be supported by sound scientific evidence. To date, however, there exists no evidence that preventive postoperative admission to intensive care is beneficial for patients having undergone lung resection surgery without immediate complications. A stratification of the risk of complications taking into consideration the patient's general state of health (e.g., nutritional status, degree of autonomy, etc.), comorbidities and type of surgery could be a useful predictive tool regarding the need for postoperative intensive care. However, serious post-operative complications remain relatively frequent and post-operative management of these intensive care patients is liable to become complex and long-lasting. In the aftermath of the validation of "enhanced recovery after surgery" (ERAS) in thoracic surgery, new protocols are needed to optimize management of patients having undergone pulmonary resection. This article focuses on the main postoperative complications and more broadly on intensive care patient management following thoracic surgery.

Ventilator Parameters in the Diagnosis and Prognosis of Acute Respiratory Distress Syndrome in Postoperative Patients: A Preliminary Study

This study investigated the usefulness of ventilator parameters in the prediction of development and outcome of acute respiratory distress syndrome (ARDS) in postoperative patients with esophageal or lung cancer on admission to the surgical intensive care unit (SICU). A total of 32 post-operative patients with lung or esophageal cancer from SICU in a tertiary medical center were retrospectively analyzed. The study patients were divided into an ARDS group (n = 21) and a non-ARDS group (n = 11). The ARDS group contained the postoperative patients who developed ARDS after lung or esophageal cancer surgery. The ventilator variables were analyzed in this study. Principal component analysis (PCA) was performed to reduce the correlated ventilator variables to a small set of variables. The top three ventilator variables with large coefficients, as determined by PCA, were considered as sensitive variables and included in the analysis model based on the rule of 10 events per variable. Firth logistic regression with selective stepwise elimination procedure was performed to identify the most important predictors of morbidity and mortality in patients with ARDS. Ventilator parameters, including rapid shallow breath index during mechanical ventilation (RSBIv), rate pressure product of ventilation (RPPv), rate pressure volume index (RPVI), mechanical work (MW), and inspiration to expiration time ratio (IER), were analyzed in this study. It was found that the ARDS patients had significantly greater respiratory rate (RR), airway resistance (Raw), RSBIv, RPPv, RPVI, positive end-expiratory pressure (PEEP), and IER and significantly lower respiratory interval (RI), expiration time (Te), flow rate (V˙), tidal volume (V_T), dynamic compliance (Cdyn), mechanical work of ventilation (MW), and MW/IER ratio than the non-ARDS patients. The non-survivors of ARDS had significantly greater peak inspiratory pressure above PEEP (PIP), RSBIv, RPPv, and RPVI than the survivors of ARDS. By using PCA, the MW/IER was found to be the most important predictor of the development of ARDS, and both RPPv and RPVI were significant predictors of mortality in patients with ARDS. In conclusion, some ventilator parameters, such as RPPv, RPVI, and MW/IER defined in this study, can be derived from ventilator readings and used to predict the development and outcome of ARDS in mechanically ventilated patients on admission to the SICU.

Normalized Pulmonary Artery Diameter Predicts Occurrence of Postpneumonectomy Respiratory Failure, ARDS, and Mortality

Hypothesizing that pulmonary artery diameter is a marker of subclinical pulmonary hypertension, we assessed its impact on postoperative outcome in patients requiring pneumonectomy. Morphometric, clinical, and laboratory data were retrospectively retrieved from files of 294 consecutive patients treated by pneumonectomy for malignancy (289 NSCLC). Pulmonary artery was measured at bifurcation level on CT scan and normalized by body surface area. Median normalized pulmonary artery diameter (cut-off for analyses) was 14 mm/m2. Postoperatively, 46 patients required re-do intubation and 30 had acute respiratory distress syndrome (ARDS). Multivariate analysis showed that Charlson Comorbidity Index >5 (p = 0.0009, OR 3.8 [1.76-8.22]), right side of pneumonectomy (p = 0.013, OR 2.37 [1.20-4.71]), and higher normalized pulmonary artery diameter (p = 0.029, OR 2.16 [1.08-4.33]) were independent predictors of re-do intubation, while Charlson Comorbidity Index >5 (p = 0.018, OR 2.55 [1.17-5.59]) and higher normalized pulmonary artery diameter (p = 0.028, OR = 2.52 [1.10-5.77]) were independently associated with occurrence of ARDS. Post-operative mortality was 8.5%. Higher normalized pulmonary artery diameter, (p = 0.026, OR 3.39[1.15-9.95]), right side of pneumonectomy (p = 0.0074, OR 4.11 [1.46-11.56]), and Charlson Comorbidity Index >5 (p = 0.0011, OR 5.56 [1.99-15.54]) were independent predictors of postoperative death. We conclude that pre-operative normalized pulmonary artery diameter predicts the risk of re-do intubation, ARDS and mortality in patients undergoing pneumonectomy for cancer.

Postoperative but not intraoperative transfusions are associated with respiratory failure after pneumonectomy

OBJECTIVES

METHODS

We performed a retrospective cohort study using prospectively collected data on consecutive pneumonectomies between 2005 and 2015. Patient records were reviewed for intraoperative/postoperative exposures. Univariable and multivariable analyses were performed.

RESULTS

Of the 251 pneumonectomies performed during the study period, 24 (9.6%) patients suffered respiratory failure. Ninety-day mortality was 5.6% (n = 14) and was more likely in patients with respiratory failure (7/24 vs 7/227, P &lt; 0.001). Intraoperative and postoperative transfusions occurred in 42.2% (n = 106) and 44.6% (n = 112) of patients, respectively and were predominantly red blood cells. On univariable analysis, both intraoperative (P = 0.03) and postoperative transfusion (P = 0.004) were associated with a higher risk of respiratory failure. The multivariable model significantly predicted respiratory failure with an area under curve (AUC) = 0.88 (P = 0.001). On multivariable analysis, the only independent predictors of respiratory failure were postoperative transfusions [adjusted odds ratio (aOR) 6.54, 95% confidence interval (CI) 1.74–24.59; P = 0.005] and lower preoperative forced expiratory volume (adjusted OR 0.96, 95% CI 0.93–0.99; P = 0.03). Estimated blood loss was not significantly different (P = 0.91) between those with (median 800 ml, interquartile range 300–2000 ml) and without respiratory failure (median 800 ml, interquartile range 300–2000 ml).

CONCLUSIONS

Respiratory failure occurred in 9.6% of patients post-pneumonectomy and confers a higher risk of 90-day mortality. Postoperative (but not intraoperative) transfusion was the strongest independent predictor associated with respiratory failure. Intraoperative transfusion may be in reaction to active/unpredictable blood loss and may not be easily modifiable. However, postoperative transfusion may be modifiable and potentially avoidable. Transfusion thresholds should be assessed in light of potential cost-benefit trade-offs.

Patients experiencing early acute respiratory failure have high postoperative mortality after pneumonectomy

OBJECTIVE

Post-pneumonectomy acute respiratory failure leading to invasive mechanical ventilation carries a severe prognosis especially when acute respiratory distress syndrome occurs. The aim of this study was to describe risk factors and outcome of acute respiratory failure.

METHODS

We retrospectively reviewed clinical files of all patients who underwent pneumonectomy in a single center between 2005 and 2015. Risk factors and outcome of acute respiratory failure were assessed in univariate and multivariate analysis.

RESULTS

Among the 543 patients who underwent pneumonectomy in the period of study, 89 (16.4%) needed reintubation within the 30th postoperative day and 60 of these (11% of all pneumonectomies) developed acute respiratory distress syndrome. In multivariate analysis, right-side of pneumonectomy (odds ratio [OR], 2.29; 95% confidence interval [CI], 1.24-4.22), chronic cardiac disease (OR, 2.15; 95% CI, 1.08-4.25), Charlson Comorbidity Index (OR, 1.35; 95% CI, 1.14-1.61), carinal resection (OR, 3.23; 95% CI, 1.26-8.29), and extrapleural pneumonectomy (OR, 8.36; 95% CI, 3.31-21.11) were identified as independent risk factors of reintubation. Thirty-day mortality was 7.7% for all pneumonectomies, 41.6% (37/89) in the invasive ventilation group, and 53.3% (32/60) in patients with acute respiratory distress syndrome. In non-reintubated patients, 30-day mortality was 1.1% (5/454). In reintubated patients, 5-year survival was 27.1% (95% CI, 17.8-41.4).

CONCLUSIONS

Early acute respiratory failure requiring reintubation remains a severe complication of pneumonectomy with a poor outcome.

High-frequency power of heart rate variability can predict the outcome of thoracic surgical patients with acute respiratory distress syndrome on admission to the intensive care unit: a prospective, single-centric, case-controlled study

BACKGROUND

The morbidity and mortality of acute respiratory distress syndrome (ARDS) remains high, and the strategic focus of ARDS research has shifted toward identifying patients at high risk of mortality early in the course of illness. This study intended to identify the heart rate variability (HRV) measure that can predict the outcome of patients with ARDS on admission to the surgical intensive care unit (SICU).

METHODS

Patients who had lung or esophageal cancer surgery were included either in the ARDS group (n = 21) if they developed ARDS after surgery or in the control group (n = 11) if they did not. The ARDS patients were further stratified into survivors and non-survivors subgroups according to their outcomes. HRV measures of the patients were used for statistical analysis.

RESULTS

The mean RR interval (mRRI), high-frequency power (HFP) and product of low-/high-frequency power ratio tidal volume and tidal volume (LHR*VT) were significantly lower (p < 0.05), while the normalized HFP to VT ratio (nHFP/VT) was significantly higher in the ARDS patients (p = 0.011). The total power (TP), low-frequency power (LFP), HFP and HFP/VT were all significantly higher in the non-survived ARDS patients, whereas Richmond Agitation-Sedation Scale (RASS) was significantly lower in the non-survived ARDS patients. After adjustment for RASS, age and gender, firth logistic regression analysis identified the HFP, TP as the significant independent predictors of mortality for ARDS patients.

CONCLUSIONS

The vagal modulation of thoracic surgical patients with ARDS was enhanced as compared to that of non-ARDS patients, and the non-survived ARDS patients had higher vagal activity than those of survived ARDS patients. The vagal modulation-related parameters such as TP and HFP were independent predictors of mortality in patients with ARDS on admission to the SICU, and the HFP was found to be the best predictor of mortality for those ARDS patients. Increased vagal modulation might be an indicator for poor prognosis in critically ill patients following thoracic surgery.

Early identification of patients at risk for acute respiratory distress syndrome among severe pneumonia: a retrospective cohort study

Background

Severe pneumonia is the predominant cause for acute respiratory distress syndrome (ARDS). Identification of ARDS from patients with severe pneumonia remains a significant clinical problem due to the overlap of clinical presentations and symptoms. Early recognition of risks for ARDS from severe pneumonia is of great clinical value.

Methods

From April 2014 to December 2015, patients with severe pneumonia at admission were retrieved from the hospital database, of which ARDS developed within 7 days were further identified. We compared the demographic and clinical characteristics at admission between severe pneumonia patients with and without ARDS development, followed by analysis of potential predictors for ARDS development and mortality. Multivariate logistic regression and receiver operating characteristic (ROC) curves were performed to screen independent risk factors and identify their sensitivity in predicting ARDS development and prognosis.

Results

Compared with severe pneumonia without ARDS development, patients with ARDS development had shorter disease duration before admission, higher lung injury score (LIS), serum fibrinogen (FiB), and positive end-expiratory pressure (PEEP), lower Marshall score, sequential organ failure assessment score and proportion of cardiovascular and gastrointestinal diseases, but similar mortality. Serum FiB >5.15 g/L [adjusted odds ratio (OR) 1.893, 95% confidence interval (CI): 1.141-3.142, P=0.014] and PEEP >6.5 cmH₂O (adjusted OR 1.651, 95% CI: 1.218-2.237, P=0.001) were independent predictors for ARDS development with a sensitivity of 58.3% and 87.5%, respectively, and pH <7.35 (adjusted OR 0.832, 95% CI: 0.702-0.985, P=0.033) was an independent risk factor for ARDS mortality with a sensitivity of 95.2%.

Conclusions

ARDS development risk could be early recognized by PEEP >6.5 cmH₂O and serum FiB >5.15 g/L in severe pneumonia patients, and pH <7.35 is a reliable prognostic factor in predicting ARDS mortality risk.

RBC transfusion is associated with increased risk of respiratory failure after pneumonectomy

BACKGROUND AND OBJECTIVES

Pneumonectomy is associated with high risk of respiratory complications. Our objective was to determine if transfusions are associated with increased rate of ARDS and respiratory failure in adults undergoing elective pneumonectomy.

METHODS

Retrospective cohort study of consecutive pneumonectomies undertaken at a tertiary hospital (2003-2013). Multivariable logistic regression was performed to adjust for confounding factors.

RESULTS

ARDS and respiratory failure occurred in 12.4% (n = 20) and 19.2% (n = 31) of 161 pneumonectomy patients, respectively, and were more likely to occur in transfused patients (P = 0.03, P < 0.001). pRBCs, FFP and platelets were transfused in 27% (n = 43), 6% (n = 9), and 2% (n = 3), respectively. On multivariable analyses utilizing blood products as continuous and binary variables, pRBC use was the only independent predictor of ARDS with odds ratio (OR) = 1.23 (95%CI:1.08-1.39, P = 0.002) and OR = 2.45 (95%CI:1.10-5.49, P = 0.03), respectively. On multivariable analyses utilizing blood products as continuous and binary variables, pRBCs were the only independent predictor of respiratory failure with OR = 1.37 (95%CI:1.16-1.60, P < 0.001) and OR = 3.17 (95%CI:1.25-8.02, P = 0.02), respectively.

CONCLUSIONS

Peri-operative pRBC use appears to be an independent risk factor for ARDS and respiratory failure after pneumonectomy. There is a significant dose-response relationship. Platelets and FFP did not appear to increase ARDS risk but this may be due to low utilization.

Preoperative pulmonary vascular morphology and its relationship to postpneumonectomy hemodynamics

RATIONALE AND OBJECTIVES

Pulmonary edema and pulmonary hypertension are postsurgical complications of pneumonectomy that may represent the remaining pulmonary vasculature's inability to accommodate the entirety of the cardiac output. Quantification of the aggregate pulmonary vascular cross-sectional area (CSA) has been used to study the development of pulmonary vascular disease in smokers. In this study, we applied this technique to demonstrate the potential utility of pulmonary vascular quantification in surgical risk assessment. Our hypothesis was that those subjects with the lowest aggregate vascular CSA in the nonoperative lung would be most likely to have elevated pulmonary vascular pressures in the postoperative period.

MATERIALS AND METHODS

A total of 61 subjects with postoperative hemodynamics and adequate imaging were identified from 159 patients undergoing pneumonectomies for mesothelioma. The total CSA of blood vessels perpendicular to the plane of computed tomographic (CT) scan slices was computed for blood vessels <5 mm(2) (CSA 5 mm). This measurement expressed as a percentage of lung parenchyma area (CSA 5%) was compared to postoperative hemodynamic measurements obtained by right heart catheterization.

RESULTS

In patients where a contrasted CT scan was used (n = 26), CSA 5% was correlated with postoperative day 0 minimum cardiac index (R = 0.37, P = .03) but not with the maximum pulmonary arterial pressures. In patients with noncontrast CT scans (n = 35), CSA 5% was inversely correlated with postoperative day 0 maximum pulmonary arterial pressures (R = 0.43, P = .03) but not with the minimum cardiac index. The preoperative perfusion fraction of the nonsurgical lung did not correlate with postoperative hemodynamics.

CONCLUSIONS

CSA of pulmonary vasculature with an area ≤5 mm(2) has potential in estimating the ability of pulmonary vascular bed to accommodate postsurgical changes in pneumonectomy.

The utility of clinical predictors of acute lung injury: towards prevention and earlier recognition

Despite significant advances in our understanding of the pathophysiology of acute lung injury, a lung-protective strategy of mechanical ventilation remains the only therapy with a proven survival advantage. Numerous pharmacologic therapies have failed to show benefit in multicenter clinical trials. The paradigm of early, goal-directed therapy of sepsis suggests greater clinical benefit may derive from initiating therapy prior to the onset of respiratory failure that requires mechanical ventilation. Thus, there is heightened interest in more accurate and complete characterization of high-risk patient populations and identification of patients in the early stage of acute lung injury, prior to the need for mechanical ventilation. This article discusses the growing literature on clinical predictors of acute lung injury (including risk factors for specific subgroups) with an emphasis on transfusion-related risk factors and recent research targeting the early identification of high-risk patients and those with early acute lung injury prior to the onset of respiratory failure.