Since critical respiratory muscle workload is a significant determinant of weaning failure, applied mechanical power (MP) during artificial ventilation may serve for readiness testing before ...proceeding on a spontaneous breathing trial (SBT). Secondary analysis of a prospective, observational study in 130 prolonged ventilated, tracheotomized patients. Calculated MP's predictive SBT outcome performance was determined using the area under receiver operating characteristic curve (AUROC), measures derived from k-fold cross-validation (likelihood ratios, Matthew's correlation coefficient MCC), and a multivariable binary logistic regression model. Thirty (23.1%) patients failed the SBT, with absolute MP presenting poor discriminatory ability (MCC 0.26; AUROC 0.68, 95%CI 0.59‒0.75, p = 0.002), considerably improved when normalized to lung-thorax compliance (LTC
-MP, MCC 0.37; AUROC 0.76, 95%CI 0.68‒0.83, p < 0.001) and mechanical ventilation P
CO
(so-called power index of the respiratory system PI
: MCC 0.42; AUROC 0.81 0.73‒0.87, p < 0.001). In the logistic regression analysis, PI
(OR 1.48 per 1000 cmH
O
/min, 95%CI 1.24‒1.76, p < 0.001) and its components LTC
-MP (1.25 per 1000 cmH
O
/min, 1.06‒1.46, p < 0.001) and mechanical ventilation P
CO
(1.17 1.06‒1.28, p < 0.001) were independently related to SBT failure. MP normalized to respiratory system compliance may help identify prolonged mechanically ventilated patients ready for spontaneous breathing.
Pulmonary infiltrates of variable etiology are one of the main reasons for hypoxemic respiratory failure leading to invasive mechanical ventilation. If pulmonary infiltrates remain unexplained or ...progress despite treatment, the histopathological result of a lung biopsy could have significant impact on change in therapy. Surgical lung biopsy is the commonly used technique, but due to its considerable morbidity and mortality, less invasive bronchoscopic transbronchial lung biopsy (TBLB) may be a valuable alternative.
Retrospective, monocentric, observational study in mechanically ventilated, critically ill patients, subjected to TBLB due to unexplained pulmonary infiltrates in the period January 2014 to July 2019. Patients' medical records were reviewed to obtain data on baseline clinical characteristics, modality and adverse events (AE) of the TBLB, and impact of the histopathological results on treatment decisions. A multivariable binary logistic regression analysis was performed to identify predictors of AE and hospital mortality, and survival curves were generated using the Kaplan-Meier method.
Forty-two patients with in total 42 TBLB procedures after a median of 12 days of mechanical ventilation were analyzed, of which 16.7% were immunosuppressed, but there was no patient with prior lung transplantation. Diagnostic yield of TBLB was 88.1%, with AE occurring in 11.9% (most common pneumothorax and minor bleeding). 92.9% of the procedures were performed as a forceps biopsy, with organizing pneumonia (OP) as the most common histological diagnosis (54.8%). Variables independently associated with hospital mortality were age (odds ratio 1.070, 95%CI 1.006-1.138; p = 0.031) and the presence of OP (0.182, 0.036-0.926; p = 0.040), the latter being confirmed in the survival analysis (log-rank p = 0.040). In contrast, a change in therapy based on histopathology alone occurred in 40.5%, and there was no evidence of improved survival in those patients.
Transbronchial lung biopsy remains a valuable alternative to surgical lung biopsy in mechanically ventilated critically ill patients. However, the high diagnostic yield must be weighed against potential adverse events and limited consequence of the histopathological result regarding treatment decisions in such patients.
The term idiopathic pulmonary arterial hypertension (IPAH) is used to categorize patients with pre-capillary pulmonary hypertension of unknown origin. There is considerable variability in the ...clinical presentation of these patients.
Using data from the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension, we performed a cluster analysis of 841 patients with IPAH based on age, sex, diffusion capacity of the lung for carbon monoxide (DLCO; <45% vs ≥45% predicted), smoking status, and presence of comorbidities (obesity, hypertension, coronary heart disease, and diabetes mellitus). A hierarchical agglomerative clustering algorithm was performed using Ward's minimum variance method. The clusters were analyzed in terms of baseline characteristics; survival; and response to pulmonary arterial hypertension (PAH) therapy, expressed as changes from baseline to follow-up in functional class, 6-minute walking distance, cardiac biomarkers, and risk.
Three clusters were identified: Cluster 1 (n = 106; 12.6%): median age 45 years, 76% females, no comorbidities, mostly never smokers, DLCO ≥45%; Cluster 2 (n = 301; 35.8%): median age 75 years, 98% females, frequent comorbidities, no smoking history, DLCO mostly ≥45%; and Cluster 3 (n = 434; 51.6%): median age 72 years, 72% males, frequent comorbidities, history of smoking, and low DLCO. Patients in Cluster 1 had a better response to PAH treatment than patients in the 2 other clusters. Survival over 5 years was 84.6% in Cluster 1, 59.2% in Cluster 2, and 42.2% in Cluster 3 (unadjusted p < 0.001 for comparison between all groups).
The population of patients diagnosed with IPAH is heterogenous. This cluster analysis identified distinct phenotypes, which differed in clinical presentation, response to therapy, and survival.
Abstract
Background
Mechanical power (MP) of artificial ventilation, the energy transferred to the respiratory system, is a chief determinant of adequate oxygenation and decarboxylation. Calculated ...MP, the product of applied airway pressure and minute ventilation, may serve as an estimate of respiratory muscle workload when switching to spontaneous breathing. The aim of the study was to assess MP’s discriminatory performance in predicting successful weaning from prolonged tracheostomy ventilation.
Methods
Prospective, observational study in 130 prolonged mechanically ventilated, tracheotomized patients in a specialized weaning center. Predictive weaning outcome ability of arterial blood gas analyses and indices derived from calculated MP at beginning and end of weaning was determined in terms of area under receiver operating characteristic curve (AUROC) and measures derived from k-fold cross-validation (likelihood ratios, diagnostic odds ratio, F
1
score, and Matthews correlation coefficient MCC).
Results
Forty-four (33.8%) patients experienced weaning failure. Absolute MP showed poor discrimination in predicting outcome; whereas specific MP (MP normalized to dynamic lung-thorax compliance, LTC
dyn
-MP) had moderate diagnostic accuracy (MCC 0.38; AUROC 0.79, 95%CI 0.71‒0.86, p < 0.001), further improved by correction for corresponding mechanical ventilation P
a
CO
2
(termed the power index of the respiratory system PI
rs
: MCC 0.52; AUROC 0.86 0.79‒0.92, p < 0.001). Diagnostic performance of MP indices increased over the course of weaning, with maximum accuracy immediately before completion (LTC
dyn
-MP: MCC 0.49; AUROC 0.86 0.78‒0.91, p < 0.001; PI
rs
: MCC 0.68; AUROC 0.92 0.86‒0.96, p < 0.001).
Conclusions
MP normalized to dynamic lung-thorax compliance, a surrogate for applied power per unit of ventilated lung volume, accurately discriminated between low and high risk for weaning failure following prolonged mechanical ventilation.
Careful patient selection is the prerequisite to raise transplant benefit. In lung transplant (LT) candidates, the effect of body mass index (BMI) on postoperative outcome remains controversial, ...possibly due to the inaccuracy of BMI in discriminating between fat and muscle mass. We therefore hypothesized that assessment of body composition by muscle mass measures is more accurate than by BMI regarding postoperative outcome.
All LT recipients from 2011 to 2014 were included and retrospectively analyzed. Lean psoas area (LPA) was assessed from pretransplant computed tomography scans, and associations with postoperative outcomes were investigated.
Included were 103 consecutive LT recipients with a mean pre-LT BMI of 22.0 ± 4.0 kg/m(2) and a mean LPA of 22.3 ± 8.3 cm(2). LPA was inversely associated with length of mechanical ventilation (p = 0.03), requirement of tracheostomy (p = 0.035), and length of stay in the intensive care unit (p = 0.02), while controlling for underlying disease, BMI, sex, age, and procedure; in contrast, BMI was not (p = 0.25, p = 0.54, and p = 0.42, respectively.). Multiple regression analysis revealed that the 6-minute walk distance at the end of pulmonary rehabilitation was significantly associated with LPA (p = 0.02).
LPA can easily be assessed in LT candidates as part of pretransplant evaluation and was significantly associated with short-term outcome, whereas BMI was not. Assessment of LPA may provide additional information on body composition beyond BMI. However, the clinical utility has to be further evaluated.
Various complications may arise from prolonged mechanical ventilation, but the risk of tracheal stenosis occurring late after translaryngeal intubation or tracheostomy is less common. This study ...aimed to determine the prevalence, type, risk factors, and management of tracheal stenoses in mechanically ventilated tracheotomized patients deemed ready for decannulation following prolonged weaning.
A retrospective observational study on 357 prolonged mechanically ventilated, tracheotomized patients admitted to a specialized weaning center over seven years. Flexible bronchoscopy was used to discern the type, level, and severity of tracheal stenosis in each case. We described the management of these stenoses and used a binary logistic regression analysis to determine independent risk factors for stenosis development.
On admission, 272 patients (76%) had percutaneous tracheostomies, and 114 patients (32%) presented mild to moderate tracheal stenosis following weaning completion, with a median tracheal cross-section reduction of 40% (IQR 25-50). The majority of stenoses (88%) were located in the upper tracheal region, most commonly resulting from localized granulation tissue formation at the site of the internal stoma (96%). The logistic regression analysis determined that obesity (OR 2.16 95%CI 1.29-3.63, P < 0.01), presence of a percutaneous tracheostomy (2.02 1.12-3.66, P = 0.020), and cricothyrotomy status (5.35 1.96-14.6, P < 0.01) were independently related to stenoses. Interventional bronchoscopy with Nd:YAG photocoagulation was a highly effective first-line treatment, with only three patients (2.6%) ultimately referred to tracheal surgery.
Tracheal stenosis is commonly observed among prolonged ventilated patients with tracheostomies, characterized by localized hypergranulation and mild to moderate airway obstruction, with interventional bronchoscopy providing satisfactory results.
The INSIGHTS-IPF registry provides one of the largest data sets of clinical data and self-reported patient related outcomes including health related quality of life (QoL) on patients with idiopathic ...pulmonary fibrosis (IPF). We aimed to describe associations of various QoL instruments between each other and with patient characteristics at baseline.
Six hundred twenty-three IPF patients with available QoL data (St George's Respiratory Questionnaire SGRQ, UCSD Shortness-of-Breath Questionnaire SoB, EuroQol visual analogue scale and index EQ-5D, Well-being Index WHO-5) were analysed. Mean age was 69.6 ± 8.7 years, 77% were males, mean disease duration 2.0 ± 3.3 years, FVC pred was 67.5 ± 17.8%, DL
pred 35.6 ± 17%.
Mean points were SGRQ total 48.3, UCSD SoB 47.8, EQ-5D VAS 66.8, and WHO-5 13.9. These instruments had a high or very high correlation (exception WHO-5 to EQ-5D VAS with moderate correlation). On bivariate analysis, QoL by SGRQ total was statistically significantly associated with clinical symptoms (NYHA; p < 0.001), number of comorbidities (p < 0.05), hospitalisation rate (p < 0.01) and disease severity (as measured by GAP score, CPI, FVC and 6-min walk test; p < 0.05 each). Multivariate analyses showed a significant association between QoL (by SGRQ total) and IPF duration, FVC, age, NYHA class and indication for long-term oxygen treatment.
Overall, IPF patients under real-life conditions have lower QoL compared to those in clinical studies. There is a meaningful relationship between QoL and various patient characteristics.
The INSIGHTS-IPF registry is registered at Clinicaltrials.gov ( NCT01695408 ).
Several studies have assessed predictors of weaning and extubation outcome in short-term mechanically ventilated patients, but there are only few studies on predictors of weaning from prolonged ...mechanical ventilation.
Retrospective, single-center, observational study at a specialized national weaning center in Germany. Patients' medical records were reviewed to obtain data on demographics, comorbidities, respiratory indices, and the result of a prospectively documented, standardized spontaneous breathing trial (SBT) upon admission to the weaning center. Respiratory indices assessed were the ventilatory ratio (VR) and parameters derived from calculated mechanical power (MP). Predictors associated with failure of prolonged weaning and failure of the SBT were assessed using a binary logistic regression model.
A total of 263 prolonged mechanically ventilated, tracheotomized patients, treated over a 5-year period were analyzed. After 3 weeks of mechanical ventilation, patients with unsuccessful weaning failed a SBT more frequently and showed significantly increased values for inspiratory positive airway pressure, driving pressure, VR, absolute MP, and MP normalized to predicted body weight and dynamic lung-thorax compliance (LTC-MP). In the logistic regression analyses, variables independently correlated with weaning failure were female gender (adjusted odds ratio 0.532 95% CI 0.291-0.973;
= 0.040), obesity (body mass index ≥ 30 kg/m
) (2.595 1.210-5.562;
= 0.014), COPD (3.209 1.563-6.589;
= 0.002), LTC-MP (3.470 1.067-11.284;
= 0.039), P
CO
on mechanical ventilation (1.101 95% CI 1.034-1.173;
= 0.003), and failure of the SBT (4.702 2.250-9.825;
< 0.001). In addition, female gender (0.401 0.216-0.745;
= 0.004), LTC-MP (3.017 1.027-8.862;
= 0.046), and P
CO
on mechanical ventilation (1.157 1.083-1.235;
< 0.001) were independent risk factors for an unsuccessful SBT.
In the present study, the derived predictors of weaning point to a crucial role of the workload imposed on respiratory muscles during spontaneous breathing. Mechanical power normalized to lung-thorax compliance was independently correlated with weaning outcome and may identify patients at high risk for weaning failure.
Abstract Background In advanced chronic obstructive pulmonary disease (COPD), hypercapnia may occur due to severe bronchial obstruction with lung hyperinflation. Non-invasive ventilation (NIV) ...provides the standard of care intended to achieve physiological PCO 2 levels, thereby reducing overall mortality. The present study aimed to evaluate pulmonary function parameters derived from spirometry (forced vital capacity FVC, forced expiratory volume in 1 s FEV1), body plethysmography (residual volume RV, total lung capacity TLC), and lung diffusion capacity for carbon monoxide (single-breath method DCO-SB, alveolar-volume corrected values DCO-VA) as predictors of chronic hypercapnia in patients with advanced COPD. Methods This monocentric, retrospective observational study included 423 COPD patients. Receiver operating characteristic (ROC) curve analysis and cross-validation were used to assess lung function parameters’ diagnostic accuracy for predicting chronic hypercapnia, with the resulting performance expressed as area under the ROC curve (AUROC). We performed univariable and multivariable binary logistic regression analysis to determine if these parameters were independently associated with chronic hypercapnia, with probabilities reported as odds ratios OR with 95% confidence intervals 95%CI. Results FVC% (AUROC 0.77 95%CI 0.72–0.81, P < 0.01) and FEV1% (AURIC 0.75 95%CI 0.70–0.79, P < 0.01) exhibited reasonable accuracy in the prediction of chronic hypercapnia, whereas lung diffusion capacity performed poorly (AUROC 0.64 95%CI 0.58–0.71 for DCO-SB%, P < 0.01). FVC% (OR 0.95 95%CI 0.93–0.97, P < 0.01) and FEV1% (OR 0.97 95%CI 0.94–0.99, P = 0.029) were the only parameters associated independently with chronic hypercapnia in logistic regression analysis. FVC and FEV1 thresholds that best separated hypercapnic from normocapnic subjects reached 56% and 33% of predicted values. Conclusions Routinely collected pulmonary function parameters, particularly FVC% and FEV1%, may predict chronic hypercapnia during COPD progression.
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