Mechanical Ventilation and Extracorporeal Membrane Oxygena tion in Acute Respiratory Insufficiency

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

Epidemiological profile and risk factors associated with death in patients receiving invasive mechanical ventilation in an adult intensive care unit from Brazil: a retrospective study

Introduction

Understanding the epidemiological profile and risk factors associated with invasive mechanical ventilation (IMV) is essential to manage the patients better and to improve health services. Therefore, our objective was to describe the epidemiological profile of adult patients in intensive care that required IMV in-hospital treatment. Also, to evaluate the risks associated with death and the influence of positive end-expiratory pressure (PEEP) and arterial oxygen pressure (PaO2) at admission in the clinical outcome.

Methods

We conducted an epidemiological study analyzing medical records of inpatients who received IMV from January 2016 to December 2019 prior to the Coronavirus Disease (COVID)-19 pandemic in Brazil. We considered the following characteristics in the statistical analysis: demographic data, diagnostic hypothesis, hospitalization data, and PEEP and PaO2 during IMV. We associated the patients' features with the risk of death using a multivariate binary logistic regression analysis. We adopted an alpha error of 0.05.

Results

We analyzed 1,443 medical records; out of those, 570 (39.5%) recorded the patients' deaths. The binary logistic regression was significant in predicting the patients' risk of death [X2(9) = 288.335; p < 0.001]. Among predictors, the most significant in relation to death risk were: age [elderly ≥65 years old; OR = 2.226 (95%CI = 1.728-2.867)]; male sex (OR = 0.754; 95%CI = 0.593-0.959); sepsis diagnosis (OR = 1.961; 95%CI = 1.481-2.595); need for elective surgery (OR = 0.469; 95%CI = 0.362-0.608); the presence of cerebrovascular accident (OR = 2.304; 95%CI = 1.502-3.534); time of hospital care (OR = 0.946; 95%CI = 0.935-0.956); hypoxemia at admission (OR = 1.635; 95%CI = 1.024-2.611), and PEEP >8 cmH2O at admission (OR = 2.153; 95%CI = 1.426-3.250).

Conclusion

The death rate of the studied intensive care unit was equivalent to that of other similar units. Regarding risk predictors, several demographic and clinical characteristics were associated with enhanced mortality in intensive care unit patients under mechanical ventilation, such as diabetes mellitus, systemic arterial hypertension, and older age. The PEEP >8 cmH2O at admission was also associated with increased mortality since this value is a marker of initially severe hypoxia.

Impact of Invasive Fungal Diseases on Survival under Veno-Venous Extracorporeal Membrane Oxygenation for ARDS

OBJECTIVE

To assess the incidence and significance of invasive fungal diseases (IFD) during veno-venous (VV) ECMO support for acute respiratory distress syndrome (ARDS).

METHODS

Retrospective analysis from January 2013 to April 2021 of all ECMO cases for ARDS at a German University Hospital. In patients with IFD (IFD patients), type of IFD, time of IFD, choice of antifungal agent, duration, and success of therapy were investigated. For comparison, patients without IFD (non-IFD patients) were selected by propensity score matching using treatment-independent variables (age, gender, height, weight, and the Sequential Organ Failure Assessment (SOFA) score at ICU admission). Demographics, hospital and ICU length of stay, duration of ECMO therapy, days on mechanical ventilation, prognostic scores (Charlson Comorbidity Index (CCI), Therapeutic Intervention Scoring System (TISS), and length of survival were assessed.

RESULTS

A total of 646 patients received ECMO, 368 patients received VV ECMO. The incidence of IFD on VV ECMO was 5.98%, with 5.43% for Candida bloodstream infections (CBSI) and 0.54% for invasive aspergillosis (IA). In IFD patients, in-hospital mortality was 81.8% versus 40.9% in non-IFD patients. The hazard ratio for death was 2.5 (CI 1.1-5.4; p: 0.023) with IFD.

CONCLUSIONS

In patients on VV ECMO for ARDS, about one in 17 contracts an IFD, with a detrimental impact on prognosis. Further studies are needed to address challenges in the diagnosis and treatment of IFD in this population.

Effectiveness of an adapted diving mask (Owner mask) for non-invasive ventilation in the COVID-19 pandemic scenario: study protocol for a randomized clinical trial

Background

Non-invasive ventilation (NIV) is indicated to avoid orotracheal intubation (OTI) to reduce hospital stay and mortality. Patients infected by SARS-CoV2 can progress to respiratory failure (RF); however, in the initial phase, they can be submitted to oxygen therapy and NIV. Such resources can produce aerosol and can cause a high risk of contagion to health professionals. Safe NIV strategies are sought, and therefore, the authors adapted diving masks to be used as NIV masks (called an Owner mask).

Objective

To assess the Owner mask safety and effectiveness regarding conventional orofacial mask for patients in respiratory failure with and without confirmation or suspicion of COVID-19.

Methods

A Brazilian multicentric study to assess patients admitted to the intensive care unit regarding their clinical, sociodemographic and anthropometric data. The primary outcome will be the rate of tracheal intubation, and secondary outcomes will include in-hospital mortality, the difference in PaO₂/FiO₂ ratio and PaCO₂ levels, time in the intensive care unit and hospitalization time, adverse effects, degree of comfort and level of satisfaction of the mask use, success rate of NIV (not progressing to OTI), and behavior of the ventilatory variables obtained in NIV with an Owner mask and with a conventional face mask. Patients with COVID-19 and clinical signs indicative of RF will be submitted to NIV with an Owner mask [NIV Owner COVID Group (n = 63)] or with a conventional orofacial mask [NIV orofacial COVID Group (n = 63)], and those patients in RF due to causes not related to COVID-19 will be allocated into the NIV Owner Non-COVID Group (n = 97) or to the NIV Orofacial Non-COVID Group (n = 97) in a randomized way, which will total 383 patients, admitting 20% for loss to follow-up.

Discussion

This is the first randomized and controlled trial during the COVID-19 pandemic about the safety and effectiveness of the Owner mask compared to the conventional orofacial mask. Experimental studies have shown that the Owner mask enables adequate sealing on the patient’s face and the present study is relevant as it aims to minimize the aerosolization of the virus in the environment and improve the safety of health professionals.

Trial registration

Brazilian Registry of Clinical Trials (ReBEC): RBR – 7xmbgsz. Registered on 15 April 2021.

A best evidence synthesis in practicing early active movements in ICU patients with mechanical ventilation

OBJECTIVE

This study summarized the best evidence of early active movements in mechanically ventilated patients in the ICU and applied it in the intensive care unit of our hospital to evaluate the practical effects.

METHODS

The best evidence for early activity in patients with mechanical ventilation in the ICU was summarized by using an evidence-based nursing method, and the results were clinically applied in the ICU. Patients who were mechanically ventilated in the ICU from January to March 2020 were selected as the control-group, and their counterparts from April to June 2020 were enrolled as the practice-group. The control-group-patients received conventional early active mobilities, and the practice-group-patients performed the best evidence-based early active mobilities. The Barthel index, muscle strength, duration of mechanical ventilation and length of ICU stay between the two groups were compared.

RESULTS

The scores of Barthel index and muscle strength of the practice group were remarkably higher than those of the control group, and the duration of mechanical ventilation and length of ICU stay were obviously shorter than those of the control group, and the difference was statistically significant (P<0.05). The incidence of deep vein thrombosis in practice group was substantially lower than that in control group (P<0.05), and the incidence of ICU acquired weakness in in practice group was critically lower than that in control group (P<0.05). The anxiety and depression scores of the two groups post-intervention were remarkably less than those before intervention (P<0.05), and the observation group had apparently lower scores than the control group (P<0.05).

CONCLUSION

The application of the best evidence of early active movement in ICU patients with mechanical ventilation can improve the daily life ability, promote the recovery of muscle strength, reduce the incidence of deep vein thrombosis and ICU acquired weakness, decrease the duration of mechanical ventilation and length of ICU hospital stay, thereby improving the clinical outcomes.

Contraindications to the Initiation of Veno-Venous ECMO for Severe Acute Respiratory Failure in Adults: A Systematic Review and Practical Approach Based on the Current Literature

(1) Background: Extracorporeal membrane oxygenation (ECMO) is increasingly used for acute respiratory failure with few absolute but many relative contraindications. The provider in charge often has a difficult time weighing indications and contraindications to anticipate if the patient will benefit from this treatment, a decision that often decides life and death for the patient. To assist in this process in coming to a good evidence-based decision, we reviewed the available literature. (2) Methods: We performed a systematic review through a literature search of the MEDLINE database of former and current absolute and relative contraindications to the initiation of ECMO treatment. (3) Results: The following relative and absolute contraindications were identified in the literature: absolute-refusal of the use of extracorporeal techniques by the patient, advanced stage of cancer, fatal intracerebral hemorrhage/cerebral herniation/intractable intracranial hypertension, irreversible destruction of the lung parenchyma without the possibility of transplantation, and contraindications to lung transplantation; relative-advanced age, immunosuppressed patients/pharmacological immunosuppression, injurious ventilator settings > 7 days, right-heart failure, hematologic malignancies, especially bone marrow transplantation and graft-versus-host disease, SAPS II score ≥ 60 points, SOFA score > 12 points, PRESERVE score ≥ 5 points, RESP score ≤ -2 points, PRESET score ≥ 6 points, and "do not attempt resuscitation" order (DN(A)R status). (4) Conclusions: We provide a simple-to-follow algorithm that incorporates absolute and relative contraindications to the initiation of ECMO treatment. This algorithm attempts to weigh pros and cons regarding the benefit for an individual patient and hopefully assists caregivers to make better, informed decisions.

Factor XIII Activity Might Already Be Impaired before Veno-Venous ECMO in ARDS Patients: A Prospective, Observational Single-Center Cohort Study

Direct complications in patients receiving extracorporeal (veno-venous) membrane oxygenation (vvECMO) are mainly either due to bleeding or thromboembolism. We aimed to evaluate the course of routine coagulation parameters and the activity of different coagulation factors—with special focus on factor XIII (F XIII)—before, during and after vvECMO in acute respiratory distress syndrome (ARDS) patients. The activity of coagulation factors and rotational thrombelastometry were analyzed in 20 ECMO patients before (T-1) and 6 h (T0), one (T1), three (T3) and seven days (T7) after the implantation, as well as one and three days after the termination of ECMO. F XIII activity was already severely decreased to 37% (30/49) before ECMO. F XIII activity was the only coagulation factor continuously declining during vvECMO, being significantly decreased at T3 (31% (26/45) vs. 24% (18/42), p = 0.0079) and T7 (31% (26/45) vs. 23% (17/37), p = 0.0037) compared to T0. Three days after termination of vvECMO, platelet count and fibrinogen nearly doubled and factors II, V, XI and XIII showed spontaneous significant increases. Severe ARDS patients showed a considerably diminished factor XIII activity before vvECMO initiation and its activity continuously declined later on. Thus, incorporation of F XIII monitoring into the regular hemostaseologic routine during vvECMO therapy seems advisable. Due to the potential development of a hypercoagulatory state after the termination of vvECMO, tight hemostasiologic monitoring should persist in the initial phase after ECMO termination.

Development and validation of a reinforcement learning algorithm to dynamically optimize mechanical ventilation in critical care

The aim of this work was to develop and evaluate the reinforcement learning algorithm VentAI, which is able to suggest a dynamically optimized mechanical ventilation regime for critically-ill patients. We built, validated and tested its performance on 11,943 events of volume-controlled mechanical ventilation derived from 61,532 distinct ICU admissions and tested it on an independent, secondary dataset (200,859 ICU stays; 25,086 mechanical ventilation events). A patient “data fingerprint” of 44 features was extracted as multidimensional time series in 4-hour time steps. We used a Markov decision process, including a reward system and a Q-learning approach, to find the optimized settings for positive end-expiratory pressure (PEEP), fraction of inspired oxygen (FiO₂) and ideal body weight-adjusted tidal volume (Vt). The observed outcome was in-hospital or 90-day mortality. VentAI reached a significantly increased estimated performance return of 83.3 (primary dataset) and 84.1 (secondary dataset) compared to physicians’ standard clinical care (51.1). The number of recommended action changes per mechanically ventilated patient constantly exceeded those of the clinicians. VentAI chose 202.9% more frequently ventilation regimes with lower Vt (5–7.5 mL/kg), but 50.8% less for regimes with higher Vt (7.5–10 mL/kg). VentAI recommended 29.3% more frequently PEEP levels of 5–7 cm H₂O and 53.6% more frequently PEEP levels of 7–9 cmH₂O. VentAI avoided high (>55%) FiO₂ values (59.8% decrease), while preferring the range of 50–55% (140.3% increase). In conclusion, VentAI provides reproducible high performance by dynamically choosing an optimized, individualized ventilation strategy and thus might be of benefit for critically ill patients.

Insight into ECMO, mortality and ARDS: a nationwide analysis of 45,647 ECMO runs

Background

Extracorporeal life support (ECLS) has become an integral part of modern intensive therapy. The choice of support mode depends largely on the indication. Patients with respiratory failure are predominantly treated with a venovenous (VV) approach. We hypothesized that mortality in Germany in ECLS therapy did not differ from previously reported literature

Methods

Inpatient data from Germany from 2007 to 2018 provided by the Federal Statistical Office of Germany were analysed. The international statistical classification of diseases and related health problems codes (ICD) and process keys (OPS) for extracorporeal membrane oxygenation (ECMO) types, acute respiratory distress syndrome (ARDS) and hospital mortality were used.

Results

In total, 45,647 hospitalized patients treated with ECLS were analysed. In Germany, 231 hospitals provided ECLS therapy, with a median of 4 VV-ECMO and 9 VA-ECMO in 2018. Overall hospital mortality remained higher than predicted in comparison to the values reported in the literature. The number of VV-ECMO cases increased by 236% from 825 in 2007 to 2768 in 2018. ARDS was the main indication for VV-ECMO in only 33% of the patients in the past, but that proportion increased to 60% in 2018. VA-ECMO support is of minor importance in the treatment of ARDS in Germany. The age distribution of patients undergoing ECLS has shifted towards an older population. In 2018, the hospital mortality decreased in VV-ECMO patients and VV-ECMO patients with ARDS to 53.9% (n = 1493) and 54.4% (n = 926), respectively.

Conclusions

ARDS is a severe disease with a high mortality rate despite ECLS therapy. Although endpoints and timing of the evaluations differed from those of the CESAR and EOLIA studies and the Extracorporeal Life Support Organization (ELSO) Registry, the reported mortality in these studies was lower than in the present analysis. Further prospective analyses are necessary to evaluate outcomes in ECMO therapy at the centre volume level.

Therapie schwerer COVID-19-Verläufe in der Intensivmedizin

Die durch die „coronavirus disease 2019“ (COVID-19) ausgelöste Pandemie hat die Intensivmedizin in den Fokus der Öffentlichkeit gerückt. Die Sterblichkeit der Erkrankten eskaliert v. a. in dem Moment, in dem die intensivmedizinischen Versorgungsmöglichkeiten enden. In der täglichen intensivmedizinischen Praxis werden die Herausforderungen durch die Besonderheiten der Infektion mit dem „severe acute respiratory syndrome coronavirus 2“ (SARS-CoV-2) und ihrer Behandlung deutlich. Diese bestehen in der Entwicklung und Therapie von Lungen‑, Multiorganversagen sowie des schweren Inflammationssyndroms. Zu diesen schweren Verläufen ist noch wenig Evidenz darüber vorhanden, welche Interventionen am effektivsten sind. Neben Erkenntnissen, die aus der raschen Durchführung klinischer Studien gewonnen wurden, stützt sich die Behandlung daher auch auf Analogien zu anderen Syndromen wie der Sepsis und dem Makrophagenaktivierungssyndrom.

[Specific treatment of acute lung failure]

Wegen der hohen Heterogenität und Dynamik des Krankheitsverlaufes stellt die Behandlung des akuten Lungenversagens Intensivmediziner vor außerordentliche Herausforderungen. Nachdem die aktuelle Definition, Pathophysiologie und die Differenzialdiagnosen in der vorliegenden Zeitschrift bereits dargestellt wurden, werden im Folgenden Möglichkeiten der spezifischen und individualisierten Therapie behandelt. Die Beatmungstherapie mit Limitierung der Tidalvolumina und Druckamplitude zeigt einen Vorteil hinsichtlich der Letalität, ist aber aufgrund der vielfältigen Ätiologie des akuten Lungenversagens im Kontext mit den unterschiedlichen Gegebenheiten individuell anzupassen. In den letzten Jahren wurde die Bedeutung der Bauchlage, der möglichst frühzeitigen Spontanatmung und der Frühmobilisation für den positiven Krankheitsverlauf erkannt. Eine individualisierte Therapie sollte die Besonderheiten des Patienten und den spezifischen Krankheitsverlauf berücksichtigen.

[COVID-19 pneumonia]

The prognosis of patients with the coronavirus disease 2019 (COVID-19) is determined by the severity of lower respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The majority of patients demonstrate mild symptoms only. However, development of pneumonia is associated with the risk of severe respiratory insufficiency. Reverse transcriptase polymerase chain reaction (RT-PCR) of specimens from the upper and/or lower respiratory tract is the gold standard for the diagnosis of COVID-19. Radiology and especially high-resolution computed tomography (HRCT) are important for diagnosis and follow-up. This narrative review provides an overview of clinical signs and the complex and unique pathophysiology of COVID-19 pneumonia. Radiological features are addressed. Therapy is mainly supportive with the most important task being management of respiratory insufficiency. Recently, promising data were presented regarding effectiveness of antiviral and anti-inflammatory drugs.

[What is evidence-based in the treatment of sepsis?]

BACKGROUND

The term sepsis was redefined in 2016 as a life-threatening organ dysfunction caused by an inadequate host response to an infection. The German S3 guidelines for the treatment of sepsis were published in 2018.

OBJECTIVE

What is evidence-based in the treatment of patients with sepsis?

MATERIAL AND METHODS

Discussion of the S3 guidelines and inclusion of study results after 2018.

RESULTS

The cornerstones for the treatment of sepsis continue to consist of early hemodynamic stabilization, anti-infection treatment and organ support procedures. Supportive and extracorporeal treatments are controversially discussed and continue to be intensively investigated.

CONCLUSION

Despite an improved understanding of the pathophysiology, there is still no effective causal sepsis treatment, i.e. directed against the pathological host reaction. The treatment of patients with sepsis is therefore still based on the basic principles of correction of volume deficits, anti-infective agents, source control and organ support, including the symptomatic treatment of vasoplegia with catecholamines.

[Treatment of severe COVID-19 courses in intensive care medicine]

Die durch die „coronavirus disease 2019“ (COVID-19) ausgelöste Pandemie hat die Intensivmedizin in den Fokus der Öffentlichkeit gerückt. Die Sterblichkeit der Erkrankten eskaliert v. a. in dem Moment, in dem die intensivmedizinischen Versorgungsmöglichkeiten enden. In der täglichen intensivmedizinischen Praxis werden die Herausforderungen durch die Besonderheiten der Infektion mit dem „severe acute respiratory syndrome coronavirus 2“ (SARS-CoV-2) und ihrer Behandlung deutlich. Diese bestehen in der Entwicklung und Therapie von Lungen‑, Multiorganversagen sowie des schweren Inflammationssyndroms. Zu diesen schweren Verläufen ist noch wenig Evidenz darüber vorhanden, welche Interventionen am effektivsten sind. Neben Erkenntnissen, die aus der raschen Durchführung klinischer Studien gewonnen wurden, stützt sich die Behandlung daher auch auf Analogien zu anderen Syndromen wie der Sepsis und dem Makrophagenaktivierungssyndrom.

Invasive and Non-Invasive Ventilation in Patients With COVID-19

BACKGROUND

The reported high mortality of COVID-19 patients in intensive care has given rise to a debate over whether patients with this disease are being intubated too soon and might instead benefit from more non-invasive ventilation.

METHODS

This review is based on articles published up to 12 June 2020 that were retrieved by a selective literature search on the topic of invasive and non-invasive ventilation for respiratory failure in COVID-19. Guideline recommendations and study data on patients with respiratory failure in settings other than COVID-19 are also considered, as are the current figures of the intensive care registry of the German Interdisciplinary Association for Intensive Care and Emergency Medicine (Deutsche Interdisziplinäre Vereinigung für Intensiv- und Notfallmedizin).

RESULTS

The high mortality figures among patients receiving invasive ventilation that have been reported in studies from abroad cannot be uncritically applied to the current situation in Germany. Study data on ventilation specifically in COVID-19 patients would be needed to do justice to the special pathophysiology of this disease, but such data are lacking. Being intubated too early is evidently associated with risks for the patient, but being intubated too late is as well. A particularly im - portant consideration is the potential harm associated with prolonged spontaneous breathing, with or without non-invasive assistance, as any increase in respiratory work can seriously worsen respiratory failure. On the other hand, it is clearly unacceptable to intubate patients too early merely out of concern that the medical staff might become infected with COVID-19 if they were ventilated non-invasively.

CONCLUSION

Nasal high flow, non-invasive ventilation, and invasive ventilation with intubation should be carried out in a stepwise treatment strategy, under appropriate intensive-care monitoring and with the observance of all relevant anti-infectious precautions. Germany is better prepared that other countries to provide COVID-19 patients with appropriate respiratory care, in view of the high per capita density of intensive-care beds and the availability of a nationwide, interdisciplinary intensive care registry for the guidance and coordination of intensive care in patients who need it.

[COVID-19 pneumonia]

Coronavirus disease 2019 (COVID-19) continues to pose a major global threat. Although a wide range of organ manifestations have now been described, the respiratory system remains in the forefront in terms of the course of infection. Severe pneumonia can develop and is generally prognostically relevant. The following article discusses currently known features of these pulmonary manifestations from a pathophysiological, symptomatological, and radiological perspective. With regard to pathophysiology, the complex nature of the acute pulmonary disease involving severe injury to the alveolar epithelium and pulmonary vascular endothelium resulting in severe respiratory failure in a proportion of patients is discussed. The differences from "classic" acute respiratory distress syndrome and the major effects these have on the treatment of COVID-19 are elucidated. Following a brief description of PCR-based pathogen identification and information on typical laboratory findings, imaging of COVID-19 pneumonia is described in greater details (typical findings, differential diagnoses, grading of the likelihood of COVID-19 pneumonia). This is followed by a description of symptoms, which develop in three phases. With regard to treatment, supportive and intensive care approaches are discussed, including O2 administration and (non-)invasive ventilation. The article concludes with a summary of the insights gained into pharmacological therapies: thrombosis prevention on the one hand, and specific antiviral and immunomodulatory therapies (remdesivir, tocilizumab, anakinra, dexamethasone) on the other.

Position Paper for the State-of-the-Art Application of Respiratory Support in Patients with COVID-19

Against the background of the pandemic caused by infection with the SARS-CoV-2 virus, the German Respiratory Society has appointed experts to develop therapy strategies for COVID-19 patients with acute respiratory failure (ARF). Here we present key position statements including observations about the pathophysiology of (ARF). In terms of the pathophysiology of pulmonary infection with SARS-CoV-2, COVID-19 can be divided into 3 phases. Pulmonary damage in advanced COVID-19 often differs from the known changes in acute respiratory distress syndrome (ARDS). Two types (type L and type H) are differentiated, corresponding to early- and late-stage lung damage. This differentiation should be taken into consideration in the respiratory support of ARF. The assessment of the extent of ARF should be based on arterial or capillary blood gas analysis under room air conditions, and it needs to include the calculation of oxygen supply (measured from the variables of oxygen saturation, hemoglobin level, the corrected values of Hüfner's factor, and cardiac output). Aerosols can cause transmission of infectious, virus-laden particles. Open systems or vented systems can increase the release of respirable particles. Procedures in which the invasive ventilation system must be opened and endotracheal intubation carried out are associated with an increased risk of infection. Personal protective equipment (PPE) should have top priority because fear of contagion should not be a primary reason for intubation. Based on the current knowledge, inhalation therapy, nasal high-flow therapy (NHF), continuous positive airway pressure (CPAP), or noninvasive ventilation (NIV) can be performed without an increased risk of infection to staff if PPE is provided. A significant proportion of patients with ARF present with relevant hypoxemia, which often cannot be fully corrected, even with a high inspired oxygen fraction (FiO2) under NHF. In this situation, the oxygen therapy can be escalated to CPAP or NIV when the criteria for endotracheal intubation are not met. In ARF, NIV should be carried out in an intensive care unit or a comparable setting by experienced staff. Under CPAP/NIV, a patient can deteriorate rapidly. For this reason, continuous monitoring and readiness for intubation are to be ensured at all times. If the ARF progresses under CPAP/NIV, intubation should be implemented without delay in patients who do not have a "do not intubate" order.

[Position Paper for the State of the Art Application of Respiratory Support in Patients with COVID-19 - German Respiratory Society]

Against the background of the pandemic caused by infection with the SARS-CoV-2, the German Society for Pneumology and Respiratory Medicine (DGP e.V.), in cooperation with other associations, has designated a team of experts in order to answer the currently pressing questions about therapy strategies in dealing with COVID-19 patients suffering from acute respiratory insufficiency (ARI).The position paper is based on the current knowledge that is evolving daily. Many of the published and cited studies require further review, also because many of them did not undergo standard review processes.Therefore, this position paper is also subject to a continuous review process and will be further developed in cooperation with the other professional societies.This position paper is structured into the following five topics:1. Pathophysiology of acute respiratory insufficiency in patients without immunity infected with SARS-CoV-22. Temporal course and prognosis of acute respiratory insufficiency during the course of the disease3. Oxygen insufflation, high-flow oxygen, non-invasive ventilation and invasive ventilation with special consideration of infectious aerosol formation4. Non-invasive ventilation in ARI5. Supply continuum for the treatment of ARIKey points have been highlighted as core statements and significant observations. Regarding the pathophysiological aspects of acute respiratory insufficiency (ARI), the pulmonary infection with SARS-CoV-2 COVID-19 runs through three phases: early infection, pulmonary manifestation and severe hyperinflammatory phase.There are differences between advanced COVID-19-induced lung damage and those changes seen in Acute Respiratory Distress Syndromes (ARDS) as defined by the Berlin criteria. In a pathophysiologically plausible - but currently not yet histopathologically substantiated - model, two types (L-type and H-type) are distinguished, which correspond to an early and late phase. This distinction can be taken into consideration in the differential instrumentation in the therapy of ARI.The assessment of the extent of ARI should be carried out by an arterial or capillary blood gas analysis under room air conditions and must include the calculation of the oxygen supply (measured from the variables of oxygen saturation, the Hb value, the corrected values of the Hüfner number and the cardiac output). In principle, aerosols can cause transmission of infectious viral particles. Open systems or leakage systems (so-called vented masks) can prevent the release of respirable particles. Procedures in which the invasive ventilation system must be opened, and endotracheal intubation must be carried out are associated with an increased risk of infection.The protection of personnel with personal protective equipment should have very high priority because fear of contagion must not be a primary reason for intubation. If the specifications for protective equipment (eye protection, FFP2 or FFP-3 mask, gown) are adhered to, inhalation therapy, nasal high-flow (NHF) therapy, CPAP therapy or NIV can be carried out according to the current state of knowledge without increased risk of infection to the staff. A significant proportion of patients with respiratory failure presents with relevant hypoxemia, often also caused by a high inspiratory oxygen fraction (FiO2) including NHF, and this hypoxemia cannot be not completely corrected. In this situation, CPAP/NIV therapy can be administered under use of a mouth and nose mask or a respiratory helmet as therapy escalation, as long as the criteria for endotracheal intubation are not fulfilled.In acute hypoxemic respiratory insufficiency, NIV should be performed in an intensive care unit or in a comparable unit by personnel with appropriate expertise. Under CPAP/NIV, a patient can deteriorate rapidly. For this reason, continuous monitoring with readiness to carry out intubation must be ensured at all times. If CPAP/NIV leads to further progression of ARI, intubation and subsequent invasive ventilation should be carried out without delay if no DNI order is in place.In the case of patients in whom invasive ventilation, after exhausting all guideline-based measures, is not sufficient, extracorporeal membrane oxygenation procedure (ECMO) should be considered to ensure sufficient oxygen supply and to remove CO2.

Platelet Function Disturbance During Veno-Venous ECMO in ARDS Patients Assessed by Multiple Electrode Aggregometry-A Prospective, Observational Cohort Study

Extracorporeal (veno-venous) membrane oxygenation (vvECMO) has been shown to have negative effects on platelet number and function. This study aimed to gain more information about the impact of vvECMO on platelet function assessed by multiple electrode aggregometry (MEA). Twenty patients with the indication for vvECMO were included. Platelet function was analyzed using MEA (Multiplate^®) before (T-1), 6 h (T0), one (T1), two (T2), three (T3), and seven (T4) days after the beginning of vvECMO. Median aggregational measurements were already below the normal reference range before vvECMO initiation. Platelet aggregation was significantly reduced 6 h after vvECMO initiation compared to T-1 and spontaneously recovered with a significant increase at T2. Platelet count dropped significantly between T-1 and T0 and continuously decreased between T0 and T4. At T4, ADP-induced platelet aggregation showed an inverse correlation with the paO2 in the oxygenator. Platelet function should be assessed by MEA before the initiation of extracorporeal circulation. Although ECMO therapy led to a further decrease in platelet aggregation after 6 h, all measurements had recovered to baseline on day two. This implies that MEA as a whole blood method might not adequately reflect the changes in platelet function in the later stages of extracorporeal circulation.

Longtime Neurologic Outcome of Extracorporeal Membrane Oxygenation and Non Extracorporeal Membrane Oxygenation Acute Respiratory Distress Syndrome Survivors

Neurologic complications following acute respiratory distress syndrome (ARDS) are well described, however, information on the neurologic outcome regarding peripheral nervous system complications in critically ill ARDS patients, especially those who received extracorporeal membrane oxygenation (ECMO) are lacking. In this prospective observational study 28 ARDS patients who survived after ECMO or conventional nonECMO treatment were examined for neurological findings. Nine patients had findings related to cranial nerve innervation, which differed between ECMO and nonECMO patients (p = 0.031). ECMO patients had severely increased patella tendon reflex (PTR) reflex levels (p = 0.027 vs. p = 0.125) as well as gastrocnemius tendon reflex (GTR) (p = 0.041 right, p = 0.149 left) were affected on the right, but not on the left side presumably associated with ECMO cannulation. Paresis (14.3% of patients) was only found in the ECMO group (p = 0.067). Paresthesia was frequent (nonECMO 53.8%, ECMO 62.5%; p = 0.064), in nonECMO most frequently due to initial trauma and polyneuropathy, in the ECMO group mainly due to impairments of N. cutaneus femoris lateralis (4 vs. 0; p = 0.031). Besides well-known central neurologic complications, more subtle complications were detected by thorough clinical examination. These findings are sufficient to hamper activities of daily living and impair quality of life and psychological health and are presumably directly related to ECMO therapy.

The effect of lung recruitment maneuvers on post-operative pulmonary complications for patients undergoing general anesthesia: A meta-analysis

BACKGROUND

Respiratory function would be impaired during general anesthesia period. Researchers devoted their energies to finding effective strategies for protecting respiratory function. Low tidal volume, positive end-expiratory pressure (PEEP), and lung recruitment maneuvers (LRMs) were recommended for patients under mechanical ventilation. However, based on the current evidence, there was no consensus on whether LRMs should be routinely used for anesthetized patients with healthy lungs, and the benefits of them remained to be determined.

MATERIALS AND METHODS

To evaluate the benefits of LRMs on patients undergoing surgery with general anesthesia, we searched relevant studies in PubMed, EMBASE, Ovid Medline and the Cochrane Library up to June 30, 2018. The primary outcome was postoperative pulmonary complications (PPCs).

RESULTS

Twelve trials involving 2756 anesthetized patients were included. The results of our study showed a significant benefit of LRMs for reducing the incidence of PPCs (RR = 0.67; 95%CI, 0.49 to 0.90; P<0.05; Chi2 = 32.94, p for heterogeneity = 0.0005, I2 = 67%). After subgroup analyses, we found LRMs combining with lung protective ventilation strategy and sustained recruitment maneuvers were associated with reducing the occurrence of PPCs. The results also revealed that the use of LRMs improved PaO2/FiO2 in non-obese patients, but with extremely high heterogeneity (I2 = 95%).

CONCLUSION

According to the findings from contemporary meta-analysis, LRMs combining with lung protective ventilation strategy may have an association with decreasing in the incidence of PPCs and improvement of oxygenation on non-obese patients. However, the conclusions must be interpreted cautiously as the outcome may be influenced dramatically due to varied LRMs and ventilation patterns.

[Indications and limitations of ECMO therapy : Considerations on evidence, treatment decisions and ethical challenges]

The present work sheds light on the possibilities and limitations of modern extracorporeal membrane oxygenation (ECMO) therapy in the case of heart or lung failure. Since the number of applications of extracorporeal lung and heart/lung replacement procedures has increased dramatically in the last few years in severely ill patients, decision-making for a meaningful indication and in the course of a possible therapy target change has become particularly difficult, especially with regard to the complex situation in organ transplantation in Germany. An attempt is made to elucidate the dilemma between data from large controlled trials and epidemiological studies and the patients' individuality.