Extracorporeal membrane-oxygenation (ECMO) has been widely used for COVID-19-related acute respiratory distress syndrome (ARDS), with a mortality rate of 37.1% based on the largest published series ...1. This rate is comparable to ECMO-supported patients with non-COVID-19-related ARDS 1. However, some reports suggest that the real-life mortality is higher than that reported above 2, including a cohort of 768 COVID-19 patients in Germany with an in-hospital mortality rate of 73% 3, and a surprising finding is given that health care resources in Germany were not notably under strain during the pandemic. To better characterize this discrepancy, we evaluated in-hospital mortality for all COVID-19 patients in Germany supported with venovenous ECMO (VV-ECMO).
High-flow nasal cannula (HFNC) has become a frequently used noninvasive form of respiratory support in acute settings; however, evidence supporting its use has only recently emerged. These guidelines ...provide evidence-based recommendations for the use of HFNC alongside other noninvasive forms of respiratory support in adults with acute respiratory failure (ARF).
The European Respiratory Society task force panel included expert clinicians and methodologists in pulmonology and intensive care medicine. The task force used the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methods to summarise evidence and develop clinical recommendations for the use of HFNC alongside conventional oxygen therapy (COT) and noninvasive ventilation (NIV) for the management of adults in acute settings with ARF.
The task force developed eight conditional recommendations, suggesting the use of 1) HFNC over COT in hypoxaemic ARF; 2) HFNC over NIV in hypoxaemic ARF; 3) HFNC over COT during breaks from NIV; 4) either HFNC or COT in post-operative patients at low risk of pulmonary complications; 5) either HFNC or NIV in post-operative patients at high risk of pulmonary complications; 6) HFNC over COT in nonsurgical patients at low risk of extubation failure; 7) NIV over HFNC for patients at high risk of extubation failure unless there are relative or absolute contraindications to NIV; and 8) trialling NIV prior to use of HFNC in patients with COPD and hypercapnic ARF.
HFNC is a valuable intervention in adults with ARF. These conditional recommendations can assist clinicians in choosing the most appropriate form of noninvasive respiratory support to provide to patients in different acute settings.
Abstract
Background
Extracorporeal carbon dioxide removal (ECCO
2
R) uses an extracorporeal circuit to directly remove carbon dioxide from the blood either in lieu of mechanical ventilation or in ...combination with it. While the potential benefits of the technology are leading to increasing use, there are very real risks associated with it. Several studies demonstrated major bleeding and clotting complications, often associated with hemolysis and poorer outcomes in patients receiving ECCO
2
R. A better understanding of the risks originating specifically from the rotary blood pump component of the circuit is urgently needed.
Methods
High-resolution computational fluid dynamics was used to calculate the hemodynamics and hemocompatibility of three current rotary blood pumps for various pump flow rates.
Results
The hydraulic efficiency dramatically decreases to 5–10% if operating at blood flow rates below 1 L/min, the pump internal flow recirculation rate increases 6–12-fold in these flow ranges, and adverse effects are increased due to multiple exposures to high shear stress. The deleterious consequences include a steep increase in hemolysis and destruction of platelets.
Conclusions
The role of blood pumps in contributing to adverse effects at the lower blood flow rates used during ECCO
2
R is shown here to be significant. Current rotary blood pumps should be used with caution if operated at blood flow rates below 2 L/min, because of significant and high recirculation, shear stress, and hemolysis. There is a clear and urgent need to design dedicated blood pumps which are optimized for blood flow rates in the range of 0.5–1.5 L/min.
The number of patients with invasive home mechanical ventilation (HMV) following unsuccessful weaning is steadily increasing, but little is known about the living conditions and health-related ...quality of life (HRQL) in these patients.
To establish detailed information on living conditions and HRQL in patients with invasive HMV.
The Severe Respiratory Insufficiency Questionnaire (SRI) was used to measure specific HRQL aspects in addition to patient interviews on individual living conditions during home visits.
Thirty-two patients with lung disease, most prominently COPD (n = 18), and neuromuscular disorders (n = 14) were included. The overall mean SRI summary scale score (range 0-100) was 53 ± 16, with a broad range amongst individuals (23-86). Neuromuscular patients were younger than those with lung diseases (49 ± 18 vs. 67 ± 11 years; p < 0.005), and although they had a higher nursing dependency and fewer comorbidities, they tended to have higher (better) SRI summary scale scores (58 ± 16 vs. 48 ± 15; p = 0.092). Living in a private home compared to living in nursing facilities did not influence the SRI scores.
Patients undergoing invasive HMV primarily following unsuccessful weaning reported an individual HRQL which, when taken together, was highly heterogeneous and ranged from very good to extremely bad. Older patients with COPD and more comorbidities are likely to have a worse HRQL than neuromuscular patients, while the living situation does not influence the HRQL.
Tuberculosis (TB) causes major public health problems worldwide. Fighting TB requires sustained efforts in health prevention, diagnosis and treatment. Previous literature has shown that conventional ...diagnostic methods like X-ray and sputum microscopy often miss early or extrapulmonary TB due to their limited sensitivity. Blood tests, while useful, lack the anatomical detail needed for precise localization of TB lesions. A possible step forward in the fight against TB could be the use of Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) and Computed Tomography (CT). This meta-analysis discusses the current literature, including the methods, results and implications of using FDG-PET-CT in the early diagnosis of TB. Analysis of the studies showed that the sensitivity of FDG-PET-CT as a potential method for early detection of TB was 82.6%.
Evidence is weak for the ability of long-term non-invasive positive pressure ventilation (NPPV) to improve survival in patients with stable hypercapnic chronic obstructive pulmonary disease (COPD). ...Previous prospective studies did not target a reduction in hypercapnia when adjusting ventilator settings. This study investigated the effect of long-term NPPV, targeted to markedly reduce hypercapnia, on survival in patients with advanced, stable hypercapnic COPD.
This investigator-initiated, prospective, multicentre, randomised, controlled clinical trial enrolled patients with stable GOLD stage IV COPD and a partial carbon dioxide pressure (PaCO2) of 7 kPa (51.9 mm Hg) or higher and pH higher than 7.35. NPPV was targeted to reduce baseline PaCO2 by at least 20% or to achieve PaCO2 values lower than 6.5 kPa (48.1 mm Hg). Patients were randomly assigned (in a 1:1 ratio) via a computer-generated randomisation sequence with a block size of four, to continue optimised standard treatment (control group) or to receive additional NPPV for at least 12 months (intervention group). The primary outcome was 1-year all-cause mortality. Analysis was by intention to treat. The intervention was unblinded, but outcome assessment was blinded to treatment assignment. This study is registered with ClinicalTrials.gov, number NCT00710541.
Patients were recruited from 36 respiratory units in Germany and Austria, starting on Oct 29, 2004, and terminated with a record of the vital status on July 31, 2011. 195 patients were randomly assigned to the NPPV group (n=102) or to the control group (n=93). All patients from the control group and the NPPV group were included in the primary analysis. 1-year mortality was 12% (12 of 102 patients) in the intervention group and 33% (31 of 93 patients) in the control group; hazard ratio 0.24 (95% CI 0.11-0.49; p=0.0004). 14 (14%) patients reported facial skin rash, which could be managed by changing the type of the mask. No other intervention-related adverse events were reported.
The addition of long-term NPPV to standard treatment improves survival of patients with hypercapnic, stable COPD when NPPV is targeted to greatly reduce hypercapnia.
German Lung Foundation; ResMed, Germany; Tyco Healthcare, Germany; and Weinmann, Germany.
The role of non-invasive ventilation (NIV) in severe COVID-19 remains a matter of debate. Therefore, the utilization and outcome of NIV in COVID-19 in an unbiased cohort was determined.
The aim was ...to provide a detailed account of hospitalized COVID-19 patients requiring non-invasive ventilation during their hospital stay. Furthermore, differences of patients treated with NIV between the first and second wave are explored.
Confirmed COVID-19 cases of claims data of the Local Health Care Funds with non-invasive and/or invasive mechanical ventilation (MV) in the spring and autumn pandemic period in 2020 were comparable analysed.
Nationwide cohort of 17.023 cases (median/IQR age 71/61-80 years, 64% male) 7235 (42.5%) patients primarily received IMV without NIV, 4469 (26.3%) patients received NIV without subsequent intubation, and 3472 (20.4%) patients had NIV failure (NIV-F), defined by subsequent endotracheal intubation. The proportion of patients who received invasive MV decreased from 75% to 37% during the second period. Accordingly, the proportion of patients with NIV exclusively increased from 9% to 30%, and those failing NIV increased from 9% to 23%. Median length of hospital stay decreased from 26 to 21 days, and duration of MV decreased from 11.9 to 7.3 days. The NIV failure rate decreased from 49% to 43%. Overall mortality increased from 51% versus 54%. Mortality was 44% with NIV-only, 54% with IMV and 66% with NIV-F with mortality rates steadily increasing from 62% in early NIV-F (day 1) to 72% in late NIV-F (>4 days).
Utilization of NIV rapidly increased during the autumn period, which was associated with a reduced duration of MV, but not with overall mortality. High NIV-F rates are associated with increased mortality, particularly in late NIV-F.
The technology underlying the development of novel ventilatory modes for long-term noninvasive ventilation of patients with chronic hypercapnia is continuously evolving. Volume-targeted ...pressure-controlled ventilation is a hybrid ventilation mode designed to combine the advantages of conventional ventilation modes, while avoiding their drawbacks. However, manufacturers have created different names and have patented algorithms and set-up variables, which can result in confusion for physicians and respiratory therapists. In addition, clear evidence for the superiority of this novel mode has not yet been established. These factors have most likely hindered more widespread use of this mode in clinical practice. The current review presents the rationale, working principles, characteristics and set-up recommendations associated with volume-targeted modes. In addition, it summarises the clinical and laboratory studies that have challenged this mode.
Background
Health-related quality of life (HRQL), life satisfaction, living conditions, patients’ attitudes towards life and death, expectations, beliefs and unmet needs are all poorly understood ...aspects associated with patients receiving invasive home mechanical ventilation (HMV) following ICU treatment and unsuccessful weaning. Therefore, the present study aimed to assess (1) HRQL, (2) life satisfaction and (3) patients’ perspectives on life and death associated with invasive HMV as the consequence of unsuccessful weaning.
Results
Patients undergoing invasive HMV with full technical supply and maximal patient care were screened over a 1-year period and assessed in their home environment. The study comprised the following: (1) detailed information on specific aspects of daily life, (2) self-evaluation of 23 specific daily life aspects, (3) HRQL assessment using the Severe Respiratory Insufficiency Questionnaire, (4) open interviews about the patient’s living situation, HRQL, unsolved problems, treatment options, dying and the concept of an afterlife. Out of 112 patients admitted to a specialized weaning centre, 50 were discharged with invasive HMV and 25 out of these (14 COPD and 11 neuromuscular patients) were ultimately enrolled. HRQL and life satisfaction were severely impaired, despite maximal patient care and full supply of technical aids. The most important areas of dissatisfaction identified were mobility, communication, social contact and care dependency. Importantly, 32% of patients would have elected to die in hindsight rather than receive invasive HMV.
Conclusions
Despite maximal patient care and a full supply of technical aids, both HRQL and life satisfaction are severely impaired in many invasive HMV patients who have failed prolonged weaning. These findings raise ethical concerns about the use of long-term invasive HMV following unsuccessful weaning.
Electrical impedance tomography (EIT) has been used to guide mechanical ventilation in ICU patients with lung collapse. Its use in patients with obstructive pulmonary diseases has been rare since ...obstructions could not be monitored on a regional level at the bedside. The current study therefore determines breath-by-breath regional expiratory time constants in intubated patients with chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS).
Expiratory time constants calculated from the global impedance EIT signal were compared to the pneumatic volume signals measured with an electronic pneumotachograph. EIT-derived expiratory time constants were additionally determined on a regional and pixelwise level. However, regional EIT signals on a single pixel level could in principle not be compared with similar pneumatic changes since these measurements cannot be obtained in patients. For this study, EIT measurements were conducted in 14 intubated patients (mean Simplified Acute Physiology Score II (SAPS II) 35 ± 10, mean time on invasive mechanical ventilation 36 ± 26 days) under four different positive end-expiratory pressure (PEEP) levels ranging from 10 to 17 cmH
O. Only patients with moderate-severe ARDS or COPD exacerbation were included into the study, preferentally within the first days following intubation.
Spearman's correlation coefficient for comparison between EIT-derived time constants and those from flow/volume curves was between 0.78 for tau (τ) calculated from the global impedance signal up to 0.83 for the mean of all pixelwise calculated regional impedance changes over the entire PEEP range. Furthermore, Bland-Altman analysis revealed a corresponding bias of 0.02 and 0.14 s within the limits of agreement ranging from - 0.50 to 0.65 s for the aforementioned calculation methods. In addition, exemplarily in patients with moderate-severe ARDS or COPD exacerbation, different PEEP levels were shown to have an influence on the distribution pattern of regional time constants.
EIT-based determination of breath-by-breath regional expiratory time constants is technically feasible, reliable and valid in invasively ventilated patients with severe respiratory failure and provides a promising tool to individually adjust mechanical ventilation in response to the patterns of regional airflow obstruction.
German Trial Register DRKS 00011650 , registered 01/31/17.
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