Clinical Guideline for Treating Acute Respiratory Insufficiency with Invasive Ventilation and Extracorporeal Membrane Oxygenation: Evidence-Based Recommendations for Choosing Modes and Setting Parameters of Mechanical Ventilation

Review article: Evaluation and care of the critically ill patient with cirrhosis

BACKGROUND

The increase in prevalence of liver disease globally will lead to a substantial incremental burden on intensive care requirements. While liver transplantation offers a potential life-saving intervention, not all patients are eligible due to limitations such as organ availability, resource constraints, ongoing sepsis or multiple organ failures. Consequently, the focus of critical care of patients with advanced and decompensated cirrhosis turns to liver-centric intensive care protocols, to mitigate the high mortality in such patients.

AIM

Provide an updated and comprehensive understanding of cirrhosis management in critical care, and which includes emergency care, secondary organ failure management (mechanical ventilation, renal replacement therapy, haemodynamic support and intensive care nutrition), use of innovative liver support systems, infection control, liver transplantation and palliative and end-of life care.

METHODS

We conducted a structured bibliographic search on PubMed, sourcing articles published up to 31 March 2024, to cover topics addressed. We considered data from observational studies, recommendations of society guidelines, systematic reviews, and meta-analyses, randomised controlled trials, and incorporated our clinical expertise in liver critical care.

RESULTS

Critical care management of the patient with cirrhosis has evolved over time while mortality remains high despite aggressive management with liver transplantation serving as a crucial but not universally available resource.

CONCLUSIONS

Implementation of organ support therapies, intensive care protocols, nutrition, palliative care and end-of-life discussions and decisions are an integral part of critical care of the patient with cirrhosis. A multi-disciplinary approach towards critical care management is likely to yield better outcomes.

Predictors associated with successful weaning of veno-venous extracorporeal membrane oxygenation and mortality in adult patients with severe acute lung failure: Protocol of a pooled data analysis of cohort studies

BACKGROUND

Severe acute lung failure (ALF) often necessitates veno-venous extracorporeal membrane oxygenation (VV-ECMO), where identifying predictors of weaning success and mortality remains crucial yet challenging. The study aims to identify predictors of weaning success and mortality in adults undergoing VV-ECMO for severe ALF, a gap in current clinical knowledge.

METHODS AND ANALYSIS

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials will be searched for cohort studies examining the predictive factors of successful weaning and mortality in adult patients on VV-ECMO due to severe ALF. Risk of bias assessment will be conducted using the Newcastle-Ottawa scale for each included study. The primary outcomes will be successful weaning from VV-ECMO and all-cause mortality. Between-study heterogeneity will be evaluated using the I2 statistic. Sensitivity, subgroup, and meta-regression analyses will be performed to ascertain potential sources of heterogeneity and assess the robustness of our results. We will use the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) tool to recommend the level of evidence.

DISCUSSION

This study seeks to provide clinically significant insights into predictors for weaning and mortality during VV-ECMO treatment for ALF, aiming to support clinical decisions and potentially influence health policy, thereby improving patient outcomes.

ETHICS AND DISSEMINATION

Given the absence of direct engagement with human subjects or access to personal medical records, ethical approval for this study is deemed unnecessary. The study findings will be shared at a scientific conference either at the global or national level. Alternatively, the results will be presented for publication in a rigorously peer-reviewed journal regarding critical care medicine.

Analysis of cerebral Interleukin-6 and tumor necrosis factor alpha patterns following different ventilation strategies during cardiac arrest in pigs

Hypoxia-induced neuroinflammation after cardiac arrest has been shown to be mitigated by different ventilation methods. In this prospective randomized animal trial, 35 landrace pigs were randomly divided into four groups: intermittent positive pressure ventilation (IPPV), synchronized ventilation 20 mbar (SV 20 mbar), chest compression synchronized ventilation 40 mbar (CCSV 40 mbar) and a control group (Sham). After inducing ventricular fibrillation, basic life support (BLS) and advanced life support (ALS) were performed, followed by post-resuscitation monitoring. After 6 hours, the animals were euthanized, and direct postmortem brain tissue samples were taken from the hippocampus (HC) and cortex (Cor) for molecular biological investigation of cytokine mRNA levels of Interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFα). The data analysis showed that CCSV 40 mbar displayed low TNFα mRNA-levels, especially in the HC, while the highest TNFα mRNA-levels were detected in SV 20 mbar. The results indicate that chest compression synchronized ventilation may have a potential positive impact on the cytokine expression levels post-resuscitation. Further studies are needed to derive potential therapeutic algorithms from these findings.

Knowledge, attitudes and practices regarding children with ICU-acquired weakness in pediatric intensive care unit among chinese medical staff: a cross-sectional survey

BACKGROUND

ICU-AW (Intensive Care Unit Acquired Weakness) is characterized by significant muscle weakness and can be caused by a variety of factors, including immobility, medication use, and underlying medical conditions.ICU-AW can affect critically ill children who have been hospitalized in the PICU for an extended period of time.The knowledge, attitude and practice level of ICU-AW of PICU medical staff directly affect the treatment of critically ill children with ICU-AW.The aim to this study was to explore the knowledge, attitudes, and practices of Chinese medical staff regarding critically ill children with intensive care unit-acquired weakness (ICU-AW) and related factors.

METHODS

A Knowledge, Attitudes, and Practices (KAP) Questionnaire regarding critically ill children with ICU-AW was distributed to a stratified sample of 530 pediatric intensive care unit (PICU) healthcare workers. The questionnaire consisted of 31 items-with scores of 45, 40, and 40 for each dimension and a total score of 125.

RESULTS

The mean total score of Chinese PICU healthcare workers for the KAP questionnaire regarding children with ICU-AW was 87.36 ± 14.241 (53-121), with mean total knowledge, attitudes, and practices scores of 30.35 ± 6.317, 30.46 ± 5.632, and 26.54 ± 6.454, respectively. The population distribution indicated that 50.56%, 46.04%, and 3.4% of healthcare workers had poor, average, and good scores, respectively. Multiple linear regression showed that gender, education, and hospital level classification influenced the KAP level of PICU healthcare workers regarding critically ill children with ICU-AW.

CONCLUSIONS

Overall, PICU healthcare workers in China have an average KAP level about ICU-AW, and the gender and education level of PICU healthcare workers, as well as the classification of hospitals where they work, predict the KAP status of healthcare workers regarding children with ICU-AW. Therefore, healthcare leaders should plan and develop specific training programs to improve the KAP level of PICU healthcare workers.

[Pathophysiology, Diagnostics and Therapy of Pulmonary Contusion - Recommendations of the Interdisciplinary Group on Thoracic Trauma of the Section NIS of the German Society for Trauma Surgery (DGU) and the German Society for Thoracic Surgery (DGT)]

Pulmonary contusion usually occurs in combination with other injuries and is indicative of a high level of force. Especially in multiply injured patients, pulmonary contusions are frequently detected. The injury is characterised by dynamic development, which might result in difficulties in recognising the actual extent of the injury at an early stage. Subsequently, correct classification of the extent of injury and appropriate initiation of therapeutic steps are essential to achieve the best possible outcome. The main goal of all therapeutic measures is to preserve lung function as best as possible and to avoid associated complications such as the development of pneumonia or Acute Respiratory Distress Syndrome (ARDS).The present report from the interdisciplinary working group "Chest Trauma" of the German Society for Trauma Surgery (DGU) and the German Society for Thoracic Surgery (DGT) includes an extensive literature review on the background, diagnosis and treatment of pulmonary contusion. Without exception, papers with a low level of evidence were included due to the lack of studies with large cohorts of patients or randomised controlled studies. Thus, the recommendations given in the present article correspond to a consensus of the aforementioned interdisciplinary working group.Computed tomography (CT) of the chest is recommended for initial diagnosis; the extent of pulmonary contusion correlates with the incidence and severity of complications. A conventional chest X-ray may initially underestimate the injury, but is useful during short-term follow-up.Therapy for pulmonary contusion is multimodal and symptom-based. In particular, intensive care therapy with lung-protective ventilation and patient positioning are key factors of treatment. In addition to invasive ventilation, non-invasive ventilation should be considered if the patient's comorbidities and compliance allows this. Furthermore, depending on the extent of the lung injury and the general patient's condition, ECMO therapy may be considered as an ultima ratio. In particular, this should only be performed at specialised hospitals, which is why patient assignment or anticipation of early transfer of the patient should be anticipated at an early time during the course.

Extreme obesity is a strong predictor for in-hospital mortality and the prevalence of long-COVID in severe COVID-19 patients with acute respiratory distress syndrome

Acute Respiratory Distress Syndrome (ARDS) is common in COVID-19 patients and is associated with high mortality. The aim of this observational study was to describe patients' characteristics and outcome, identifying potential risk factors for in-hospital mortality and for developing Long-COVID symptoms. This retrospective study included all patients with COVID-19 associated ARDS (cARDS) in the period from March 2020 to March 2021 who were invasively ventilated at the intensive care unit (ICU) of the University Hospital Dresden, Germany. Between October 2021 and December 2021 patients discharged alive (at minimum 6 months after hospital discharge-midterm survival) were contacted and interviewed about persistent symptoms possibly associated with COVID-19 as well as the quality of their lives using the EQ-5D-5L-questionnaire. Long-COVID was defined as the occurrence of one of the symptoms at least 6 months after discharge. Risk factors for mortality were assessed with Cox regression models and risk factors for developing Long-COVID symptoms by using relative risk (RR) regression. 184 Patients were included in this study (male: n = 134 (73%), median age 67 (range 25-92). All patients were diagnosed with ARDS according to the Berlin Definition. 89% of patients (n = 164) had severe ARDS (Horovitz-index < 100 mmHg). In 27% (n = 49) extracorporeal membrane oxygenation was necessary to maintain gas exchange. The median length of in-hospital stay was 19 days (range 1-60). ICU mortality was 51%, hospital mortality 59%. Midterm survival (median 11 months) was 83% (n = 55) and 78% (n = 43) of these patients presented Long-COVID symptoms with fatigue as the most common symptom (70%). Extreme obesity (BMI > 40 kg/m²) was the strongest predictor for in-hospital mortality (hazard ratio: 3.147, confidence interval 1.000-9.897) and for developing Long-COVID symptoms (RR 1.61, confidence interval 1.26-2.06). In-hospital mortality in severe cARDS patients was high, but > 80% of patients discharged alive survived the midterm observation period. Nonetheless, most patients developed Long-COVID symptoms. Extreme obesity with BMI > 40 kg/m² was identified as independent risk factor for in-hospital mortality and for developing Long-COVID symptoms.Trial registration DRKS-ID DRKS00027856.

Invasiveness of Ventilation Therapy Is Associated to Prevalence of Secondary Bacterial and Fungal Infections in Critically Ill COVID-19 Patients

Superinfections are a fundamental critical care problem, and their significance in severe COVID-19 cases needs to be determined. This study analyzed data from the Lean European Open Survey on SARS-CoV-2-Infected Patients (LEOSS) cohort focusing on intensive care patients. A retrospective analysis of patient data from 840 cases of COVID-19 with critical courses demonstrated that co-infections were frequently present and were primarily of nosocomial origin. Furthermore, our analysis showed that invasive therapy procedures accompanied an increased risk for healthcare-associated infections. Non-ventilated ICU patients were rarely affected by secondary infections. The risk of infection, however, increased even when non-invasive ventilation was used. A further, significant increase in infection rates was seen with the use of invasive ventilation and even more so with extracorporeal membrane oxygenation (ECMO) therapy. The marked differences among ICU techniques used for the treatment of COVID-19-induced respiratory failure in terms of secondary infection risk profile should be taken into account for the optimal management of critically ill COVID-19 patients, as well as for adequate antimicrobial therapy.

High PEEP Levels during CPR Improve Ventilation without Deleterious Haemodynamic Effects in Pigs

Background: Invasive ventilation during cardiopulmonary resuscitation (CPR) is very complex due to unique thoracic pressure conditions. Current guidelines do not provide specific recommendations for ventilation during ongoing chest compressions regarding positive end-expiratory pressure (PEEP). This trial examines the cardiopulmonary effects of PEEP application during CPR. Methods: Forty-two German landrace pigs were anaesthetised, instrumented, and randomised into six intervention groups. Three PEEP levels (0, 8, and 16 mbar) were compared in high standard and ultralow tidal volume ventilation. After the induction of ventricular fibrillation, mechanical chest compressions and ventilation were initiated and maintained for thirty minutes. Blood gases, ventilation/perfusion ratio, and electrical impedance tomography loops were taken repeatedly. Ventilation pressures and haemodynamic parameters were measured continuously. Postmortem lung tissue damage was assessed using the diffuse alveolar damage (DAD) score. Statistical analyses were performed using SPSS, and p values <0.05 were considered significant. Results: The driving pressure (Pdrive) showed significantly lower values when using PEEP 16 mbar than when using PEEP 8 mbar (p = 0.045) or PEEP 0 mbar (p < 0.001) when adjusted for the ventilation mode. Substantially increased overall lung damage was detected in the PEEP 0 mbar group (vs. PEEP 8 mbar, p = 0.038; vs. PEEP 16 mbar, p = 0.009). No significant differences in mean arterial pressure could be detected. Conclusion: The use of PEEP during CPR seems beneficial because it optimises ventilation pressures and reduces lung damage without significantly compromising blood pressure. Further studies are needed to examine long-term effects in resuscitated animals.

Early spontaneous breathing for acute respiratory distress syndrome in individuals with COVID-19

BACKGROUND

Acute respiratory distress syndrome (ARDS) represents the most severe course of COVID-19 (caused by the SARS-CoV-2 virus), usually resulting in a prolonged stay in an intensive care unit (ICU) and high mortality rates. Despite the fact that most affected individuals need invasive mechanical ventilation (IMV), evidence on specific ventilation strategies for ARDS caused by COVID-19 is scarce. Spontaneous breathing during IMV is part of a therapeutic concept comprising light levels of sedation and the avoidance of neuromuscular blocking agents (NMBA). This approach is potentially associated with both advantages (e.g. a preserved diaphragmatic motility and an optimised ventilation-perfusion ratio of the ventilated lung), as well as risks (e.g. a higher rate of ventilator-induced lung injury or a worsening of pulmonary oedema due to increases in transpulmonary pressure). As a consequence, spontaneous breathing in people with COVID-19-ARDS who are receiving IMV is subject to an ongoing debate amongst intensivists.

OBJECTIVES

To assess the benefits and harms of early spontaneous breathing activity in invasively ventilated people with COVID-19 with ARDS compared to ventilation strategies that avoid spontaneous breathing.

SEARCH METHODS

We searched the Cochrane COVID-19 Study Register (which includes CENTRAL, PubMed, Embase, Clinical Trials.gov WHO ICTRP, and medRxiv) and the WHO COVID-19 Global literature on coronavirus disease to identify completed and ongoing studies from their inception to 2 March 2022.

SELECTION CRITERIA

Eligible study designs comprised randomised controlled trials (RCTs) that evaluated spontaneous breathing in participants with COVID-19-related ARDS compared to ventilation strategies that avoided spontaneous breathing (e.g. using NMBA or deep sedation levels). Additionally, we considered controlled before-after studies, interrupted time series with comparison group, prospective cohort studies and retrospective cohort studies. For these non-RCT studies, we considered a minimum total number of 50 participants to be compared as necessary for inclusion. Prioritised outcomes were all-cause mortality, clinical improvement or worsening, quality of life, rate of (serious) adverse events and rate of pneumothorax. Additional outcomes were need for tracheostomy, duration of ICU length of stay and duration of hospitalisation.

DATA COLLECTION AND ANALYSIS

We followed the methods outlined in the Cochrane Handbook for Systematic Reviews of Interventions. Two review authors independently screened all studies at the title/abstract and full-text screening stage. We also planned to conduct data extraction and risk of bias assessment in duplicate. We planned to conduct meta-analysis for each prioritised outcome, as well as subgroup analyses of mortality regarding severity of oxygenation impairment and duration of ARDS. In addition, we planned to perform sensitivity analyses for studies at high risk of bias, studies using NMBA in addition to deep sedation level to avoid spontaneous breathing and a comparison of preprints versus peer-reviewed articles. We planned to assess the certainty of evidence using the GRADE approach.

MAIN RESULTS

We identified no eligible studies for this review.

AUTHORS' CONCLUSIONS

We found no direct evidence on whether early spontaneous breathing in SARS-CoV-2-induced ARDS is beneficial or detrimental to this particular group of patients.  RCTs comparing early spontaneous breathing with ventilatory strategies not allowing for spontaneous breathing in SARS-CoV-2-induced ARDS are necessary to determine its value within the treatment of severely ill people with COVID-19. Additionally, studies should aim to clarify whether treatment effects differ between people with SARS-CoV-2-induced ARDS and people with non-SARS-CoV-2-induced ARDS.

Extracorporeal membrane oxygenation

BACKGROUND

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) and veno-arterial extracorporeal membrane oxygenation (VA-ECMO), also known as extracorporeal life support (ECLS), can both be used to treat patients with acute pulmonary or cardiovascular failure.

METHODS

This review is based on publications retrieved by a selective search in PubMed on the topics of cardiogenic shock and acute pulmonary failure, also known as the acute respiratory distress syndrome (ARDS), as well as on ECMO. Attention was given chiefly to randomized, controlled trials and guidelines.

RESULTS

Initial findings from prospective, randomized trials of VV-ECMO are now available. Trials of ECLS therapy are now in progress or planned. A meta-analysis of two randomized, controlled trials of VV-ECMO for ARDS revealed more frequent survival 90 days after randomization among patients treated with VV-ECMO, compared to the control groups (36% vs. 48%; RR = 0.75 [95% confidence interval 0.6; 0.94]). For selected patients, after evaluation of the benefit-risk profile, VV-ECMO is a good treatment method for severe pulmonary failure, and ECLS for cardiogenic shock and resuscitation. The goal is to secure the circulation so that native heart function can be stabilized in the patient's further course or a permanent left-heart support system can be implanted, or else to support lung function until recovery.

CONCLUSION

ECMO is a valid option in selected patients when conservative treatment has failed.

Determination of individual bile acids in acute respiratory distress syndrome reveals a specific pattern of primary and secondary bile acids and a shift to the acidic pathway as an adaptive response to the critical condition

OBJECTIVES

Cholestasis and elevated serum bile¹ acid levels are common in critically ill patients. This study aims to define the specific pattern of bile acids associated with acute respiratory distress syndrome (ARDS) and the changes in pattern over time.

METHODS

Prospective observational study. Serum samples of 70 ARDS patients were analyzed for primary bile acids (cholic acid, chenodeoxycholic acid) and secondary bile acids (deoxycholic acid, litocholic acid, and ursodeoxycholic acid) as well as their glycine and taurine glycation products.

RESULTS

Primary bile acid levels increased from day zero to day five by almost 50% (p<0.05). This change bases on a statistically significant increase in all primary bile acids between day 0 and day 5 (cholic acid [CA] p=0.001, taurocholic acid [TCA] p=0.004, glycocholic acid [GCA] p<0.001, chenodeoxycholic acid [CDCA] p=0.036, taurochenodeoxycholic acid [TCDCA] p<0.001, glycochenodeoxycholic acid [GCDCA] p<0.001). Secondary bile acids showed predominantly decreased levels on day 0 compared to the control group and remained stable throughout the study period; the differences between day zero and day five were not statistically significant. Non-survivors exhibited significantly higher levels of TCDCA on day 5 (p<0.05) than survivors. This value was also independently associated with survival in a logistic regression model with an odds ratio of 2.24 (95% CI 0.53-9.46).

CONCLUSIONS

The individual bile acid profile of this ARDS patient cohort is unique compared to other disease states. The combination of changes in individual bile acids reflects a shift toward the acidic pathway of bile acid synthesis. Our results support the concept of ARDS-specific plasma levels of bile acids in a specific pattern as an adaptive response mechanism.

Entwicklung und Fortschritt in der Beatmungsmedizin

Die Beatmungsmedizin umfasst drei wesentliche Bereiche: 1) die akute Anwendung in der Intensivmedizin, 2) Respiratorentwöhnung (Weaning) und 3) die Langzeitanwendung und damit die außerklinische Beatmung. Heute besteht aufgrund zunehmender wissenschaftlicher Evidenz eine sehr differenzierte Herangehensweise an die Beatmungsmedizin, was die Bereiche gleichermaßen betrifft. Aus diesem Grund existieren in Deutschland mehrere Leitlinien zum Thema Beatmungsmedizin. Die aktuelle Entwicklung der Beatmungsmedizin wird in Deutschland zudem durch die Corona-Pandemie, wohl aber auch durch die Ökonomisierung im Gesundheitssystem geprägt. Auffällig ist gegenwärtig eine stetig wachsende Zunahme der außerklinischen Beatmung, während die Kapazitäten in der Intensivmedizin fallend sind. Der aktuelle Beitrag greift diese Entwicklungen weiter auf.

ECMO use in Germany: An analysis of 29,929 ECMO runs

Background

Extracorporeal Membrane Oxygenation (ECMO) use is increasing despite limited evidence. The aim of this study was to demonstrate heterogeneity of ECMO use and its association with hospital size and annual frequency in Germany.

Methods

This is a database analysis of all ECMO cases in Germany from 2010 to 2016 using the German Diagnosis Related Groups (DRG) coding system for ECMO.

Results

During the study period, 510 hospitals performed 29,929 ECMO runs (12,572 vvECMO, 11,504 vaECMO, 1993 pECLA) with an increase over time. Mortality ranged between 58% and 66% for vaECMO cases and 66% and 53% for vvECMO cases. 304 (61%) hospitals performed only one ECMO per year. 78%% of all ECMO runs were performed in centres with more than 20 cases per year and more than half of all ECMO runs were performed in hospitals with >1.000 beds. Mortality for vv and vaECMO was highest in very small hospitals (< 200 beds; 70%; 74%) and very large hospitals (>1000 beds; 60%; 62%).

Conclusions

Use of ECMO is still increasing and a substantial proportion of hospitals performs very few ECMO runs. Small hospitals had a significantly higher mortality, but dependence on hospital size and ECMO mortality was irregular.

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.

[Management of Adult Community-Acquired Pneumonia and Prevention - Update 2021 - Guideline of the German Respiratory Society (DGP), the Paul-Ehrlich-Society for Chemotherapy (PEG), the German Society for Infectious Diseases (DGI), the German Society of Medical Intensive Care and Emergency Medicine (DGIIN), the German Viological Society (DGV), the Competence Network CAPNETZ, the German College of General Practitioneers and Family Physicians (DEGAM), the German Society for Geriatric Medicine (DGG), the German Palliative Society (DGP), the Austrian Society of Pneumology Society (ÖGP), the Austrian Society for Infectious and Tropical Diseases (ÖGIT), the Swiss Respiratory Society (SGP) and the Swiss Society for Infectious Diseases Society (SSI)]

The present guideline provides a new and updated concept of the management of adult patients with community-acquired pneumonia. It replaces the previous guideline dating from 2016.The guideline was worked out and agreed on following the standards of methodology of a S3-guideline. This includes a systematic literature search and grading, a structured discussion of recommendations supported by the literature as well as the declaration and assessment of potential conflicts of interests.The guideline has a focus on specific clinical circumstances, an update on severity assessment, and includes recommendations for an individualized selection of antimicrobial treatment.The recommendations aim at the same time at a structured assessment of risk for adverse outcome as well as an early determination of treatment goals in order to reduce mortality in patients with curative treatment goal and to provide palliation for patients with treatment restrictions.

Comparison of ETCO2 Value and Blood Gas PCO2 Value of Patients Receiving Non-invasive Mechanical Ventilation Treatment in Emergency Department

Capnography is the non-invasive measurement and graphic representation of the partial pressure of CO2 in expiration. Although there are many studies in the literature comparing the partial pressure of carbon dioxide (pCO2) and end-tidal CO2 (ETCO2) values in patients who underwent IMV (invasive mechanical ventilation), there are no studies showing their interchangeable applicability in patients who received NIMV (non-IMV). We aimed to evaluate whether the use of ETCO2 in the treatment process can replace pCO2 use in patients scheduled for NIMV treatment in the emergency department. Patients who applied to the emergency department with respiratory distress between March 2019 and January 2020, who were diagnosed with acute cardiogenic edema or acute chronic obstructive pulmonary disease (COPD) exacerbation, and who needed NIMV were included in the study. General characteristics of the patients and the pCO2 and ETCO2 values were measured in the blood gas 1 h after the NIMV application was started. 64.2% (99 patients) of the patients included in the study were male, and 35.8% (55 patients) were female. The mean age of the patients included in the study was 69.1 ± 12.2 years. The mean pCO2 values ​​were measured as 52.6 ± 13.2. The mean of ETCO2 values ​​measured simultaneously was 33.6 ± 10.1. There was a significant difference between the controlled pCO2 values ​​and ETCO2 values ​​at the first hour of NIMV treatment (Z: - 10.640, p < 0.001). The ETCO2 level was found to be different in our patients who received NIMV treatment, which could not be used instead of the pCO2 level.

Cerebrovascular autoregulation and arterial carbon dioxide in patients with acute respiratory distress syndrome: a prospective observational cohort study

BACKGROUND

Early hypercapnia is common in patients with acute respiratory distress syndrome (ARDS) and is associated with increased mortality. Fluctuations of carbon dioxide have been associated with adverse neurological outcome in patients with severe respiratory failure requiring extracorporeal organ support. The aim of this study was to investigate whether early hypercapnia is associated with impaired cerebrovascular autoregulation during the acute phase of ARDS.

METHODS

Between December 2018 and November 2019, patients who fulfilled the Berlin criteria for ARDS, were enrolled. Patients with a history of central nervous system disorders, cerebrovascular disease, chronic hypercapnia, or a life expectancy of less than 24 h were excluded from study participation. During the acute phase of ARDS, cerebrovascular autoregulation was measured over two time periods for at least 60 min. Based on the values of mean arterial blood pressure and near-infrared spectroscopy, a cerebral autoregulation index (COx) was calculated. The time with impaired cerebral autoregulation was calculated for each measurement and was compared between patients with and without early hypercapnia [defined as an arterial partial pressure of carbon dioxide (PaCO2) ≥ 50 mmHg with a corresponding arterial pH < 7.35 within the first 24 h of ARDS diagnosis].

RESULTS

Of 66 patients included, 117 monitoring episodes were available. The mean age of the study population was 58.5 ± 16 years. 10 patients (15.2%) had mild, 28 (42.4%) moderate, and 28 (42.4%) severe ARDS. Nineteen patients (28.8%) required extracorporeal membrane oxygenation. Early hypercapnia was present in 39 patients (59.1%). Multivariable analysis did not show a significant association between early hypercapnia and impaired cerebrovascular autoregulation (B = 0.023 [95% CI - 0.054; 0.100], p = 0.556). Hypocapnia during the monitoring period was significantly associated with impaired cerebrovascular autoregulation [B = 0.155 (95% CI 0.014; 0.296), p = 0.032].

CONCLUSION

Our results suggest that moderate permissive hypercapnia during the acute phase of ARDS has no adverse effect on cerebrovascular autoregulation and may be tolerated to a certain extent to achieve low tidal volumes. In contrast, episodes of hypocapnia may compromise cerebral blood flow regulation. Trial registration ClinicalTrials.gov; registration number: NCT03949738; date of registration: May 14, 2019.

German recommendations for critically ill patients with COVID‑19

Since December 2019, a novel coronavirus (severe acute respiratory syndrome—coronavirus 2, SARS-CoV-2) has rapidly spread around the world resulting in an acute respiratory illness pandemic. The majority of patients presents with mild symptoms of coronavirus disease 2019 (COVID-19). However, about 5% become critically ill and require intensive care treatment. Acute hypoxemic failure with severe dyspnea and an increased respiratory rate (>30/min) usually leads to ICU admission. At that point, bilateral pulmonary infiltrates are typically seen. Patients often develop a severe acute respiratory distress syndrome (ARDS). To date there is no specific treatment available—the main goal of supportive therapy is to ascertain adequate oxygenation. Early intubation and repeated prone positioning are key elements in treating hypoxemic COVID-19 patients. Strict adherence to basic infection control measures (including hand hygiene) and use of personal protection equipment (PPE) are essential in the care of patients. Procedures that lead to formation of aerosols should be avoided where possible and carried out with utmost precaution.

COVID-19 Induced Acute Respiratory Distress Syndrome-A Multicenter Observational Study

Background: Proportions of patients dying from the coronavirus disease-19 (COVID-19) vary between different countries. We report the characteristics; clinical course and outcome of patients requiring intensive care due to COVID-19 induced acute respiratory distress syndrome (ARDS).

Methods: This is a retrospective, observational multicentre study in five German secondary or tertiary care hospitals. All patients consecutively admitted to the intensive care unit (ICU) in any of the participating hospitals between March 12 and May 4, 2020 with a COVID-19 induced ARDS were included.

Results: A total of 106 ICU patients were treated for COVID-19 induced ARDS, whereas severe ARDS was present in the majority of cases. Survival of ICU treatment was 65.0%. Median duration of ICU treatment was 11 days; median duration of mechanical ventilation was 9 days. The majority of ICU treated patients (75.5%) did not receive any antiviral or anti-inflammatory therapies. Venovenous (vv) ECMO was utilized in 16.3%. ICU triage with population-level decision making was not necessary at any time. Univariate analysis associated older age, diabetes mellitus or a higher SOFA score on admission with non-survival during ICU stay.

Conclusions: A high level of care adhering to standard ARDS treatments lead to a good outcome in critically ill COVID-19 patients.

Lower versus higher hemoglobin threshold for transfusion in ARDS patients with and without ECMO

BACKGROUND

Efficacy and safety of different hemoglobin thresholds for transfusion of red blood cells (RBCs) in adults with an acute respiratory distress syndrome (ARDS) are unknown. We therefore assessed the effect of two transfusion thresholds on short-term outcome in patients with ARDS.

METHODS

Patients who received transfusions of RBCs were identified from a cohort of 1044 ARDS patients. After propensity score matching, patients transfused at a hemoglobin concentration of 8 g/dl or less (lower-threshold) were compared to patients transfused at a hemoglobin concentration of 10 g/dl or less (higher-threshold). The primary endpoint was 28-day mortality. Secondary endpoints included ECMO-free, ventilator-free, sedation-free, and organ dysfunction-free composites.

MEASUREMENTS AND MAIN RESULTS

One hundred ninety-two patients were eligible for analysis of the matched cohort. Patients in the lower-threshold group had similar baseline characteristics and hemoglobin levels at ARDS onset but received fewer RBC units and had lower hemoglobin levels compared with the higher-threshold group during the course on the ICU (9.1 [IQR, 8.7-9.7] vs. 10.4 [10-11] g/dl, P < 0.001). There was no difference in 28-day mortality between the lower-threshold group compared with the higher-threshold group (hazard ratio, 0.94 [95%-CI, 0.59-1.48], P = 0.78). Within 28 days, 36.5% (95%-CI, 27.0-46.9) of the patients in the lower-threshold group compared with 39.5% (29.9-50.1) of the patients in the higher-threshold group had died. While there were no differences in ECMO-free, sedation-free, and organ dysfunction-free composites, the chance for successful weaning from mechanical ventilation within 28 days after ARDS onset was lower in the lower-threshold group (subdistribution hazard ratio, 0.36 [95%-CI, 0.15-0.86], P = 0.02).

CONCLUSIONS

Transfusion at a hemoglobin concentration of 8 g/dl, as compared with a hemoglobin concentration of 10 g/dl, was not associated with an increase in 28-day mortality in adults with ARDS. However, a transfusion at a hemoglobin concentration of 8 g/dl was associated with a lower chance for successful weaning from the ventilator during the first 28 days after ARDS onset.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03871166.

Mechanical ventilation of patients in helicopter emergency medical service transport: an international survey

BACKGROUND

Mechanical ventilation in helicopter emergency medical service (HEMS) environments is a procedure which carries a significant risk of complications. Limited data on the quality and performance of mechanical ventilation in HEMS are available in the literature.

METHOD

We conducted an international survey to evaluate mechanical ventilation infrastructure in HEMS and collect data of transported ventilated patients. From June 20-22, 2019, the participating HEMS bases were asked to provide data via a web-based platform. Vital parameters and ventilation settings of the patients at first patient contact and at handover were compared using non-parametric statistical tests.

RESULTS

Out of 215 invited HEMS bases, 53 responded. Respondents were from Germany, Denmark, United Kingdom, Luxembourg, Austria and Switzerland. Of the HEMS bases, all teams were physician staffed, mainly anesthesiologists (79%), the majority were board certified (92.5%) and trained in intensive care medicine (89%) and had a median (range) experience in HEMS of 9 (0-25) years. HEMS may provide a high level of expertise in mechanical ventilation whereas the majority of ventilators are able to provide pressure controlled ventilation and continuous positive airway pressure modes (77%). Data of 30 ventilated patients with a median (range) age of 54 (21-100) years and 53% male gender were analyzed. Of these, 24 were primary missions and 6 interfacility transports. At handover, oxygen saturation (p < 0.01) and positive end-expiratory pressure (p = 0.04) of the patients were significantly higher compared to first patient contact.

CONCLUSION

In this survey, the management of ventilated HEMS-patients was not associated with ventilation related serious adverse events. Patient conditions, training of medical crew and different technical and environmental resources are likely to influence management. Further studies are necessary to assess safety and process quality of mechanical ventilation in HEMS.

TRIAL REGISTRATION

The survey was prospectively registered at Research Registry ( researchregistry2925 ).

Respiratory Support in Severely or Critically Ill ICU Patients With COVID-19 in Wuhan, China

This case series aimed to describe the clinical characteristics of severely or critically ill patients with COVID-19 and compare the clinical characteristics of patients who received invasive respiratory support with those of patients who received noninvasive respiratory support. We included all confirmed severe or critical illness cases of COVID-19 admitted to the Intensive Care Unit (ICU) of Zhongnan Hospital of Wuhan University, a COVID-19-designated hospital, from January 8 to March 12, 2020. Cases were analyzed for epidemiological, demographic, clinical, APACHE II, SOFA, radiological features and laboratory data. Outcomes of all patients were followed up as of March 12, 2020. This newly emerging virus had caused 55 confirmed severe or critical illness cases in ICU of a COVID-19-designated hospital. Most of the infected patients were men; more than half had underlying diseases, including hypertension, coronary artery disease and diabetes. The median age was 63 years old. Common symptoms at onset of illness were fever, fatigue and dry cough. Five (9.1%) hospitalized patients were presumed to have been infected in the hospital, and 4 (7.3%) health care workers were infected in their work. Of the 55 confirmed severe or critical illness cases, 10 (18.2%) patients died during the follow-up period as of March 12 with the median follow-up period of 28 days (interquartile range 16-35). Nine patients received VV-ECMO for severe respiratory failure and 4 (44.4%) patients died. Moreover, 28 patients received invasive respiratory support and 14 (50.0%) patients died. In this single-center study, 55 severely or critically ill ICU patients were confirmed to have COVID-19 in Wuhan and the overall mortality was 29.1%. Totally 28 (50.9%) of severely or critically ill ICU patients received invasive respiratory support and 14 (50.0%) died during the follow-up period.

Preemptive veno-venous ECMO support in a patient with anticipated difficult airway: A case report

This report presents a case of endotracheal metastasis in which elective veno-venous extracorporeal membrane oxygenation (VV ECMO) was used to undergo tracheal laser-surgery prior to establishment of a definitive airway. Specifically, we describe the respiratory and airway management in an adult patient from the preclinical phase throughout elective preoperative ECMO implantation to postoperative ECMO weaning and decannulation in the Intensive Care Unit. This case report lends further supports to the idea that the extracorporeal membrane oxygenation could be electively used to provide safe environment for surgery in situations where the standard maneuvers of sustaining adequate gas exchange are anticipated to fail.

Organizational factors associated with adherence to low tidal volume ventilation: a secondary analysis of the CHECKLIST-ICU database

Background

Survival benefit from low tidal volume (V_T) ventilation (LTVV) has been demonstrated for patients with acute respiratory distress syndrome (ARDS), and patients not having ARDS could also benefit from this strategy. Organizational factors may play a role on adherence to LTVV. The present study aimed to identify organizational factors with an independent association with adherence to LTVV.

Methods

Secondary analysis of the database of a multicenter two-phase study (prospective cohort followed by a cluster-randomized trial) performed in 118 Brazilian intensive care units. Patients under mechanical ventilation at day 2 were included. LTVV was defined as a V_T ≤ 8 ml/kg PBW on the second day of ventilation. Data on the type and number of beds of the hospital, teaching status, nursing, respiratory therapists and physician staffing, use of structured checklist, and presence of protocols were tested. A multivariable mixed-effect model was used to assess the association between organizational factors and adherence to LTVV.

Results

The study included 5719 patients; 3340 (58%) patients received LTVV. A greater number of hospital beds (absolute difference 7.43% [95% confidence interval 0.61–14.24%]; p = 0.038), use of structured checklist during multidisciplinary rounds (5.10% [0.55–9.81%]; p = 0.030), and presence of at least one nurse per 10 patients during all shifts (17.24% [0.85–33.60%]; p = 0.045) were the only three factors that had an independent association with adherence to LTVV.

Conclusions

Number of hospital beds, use of a structured checklist during multidisciplinary rounds, and nurse staffing are organizational factors associated with adherence to LTVV. These findings shed light on organizational factors that may improve ventilation in critically ill patients.

Mechanical ventilation in Spain, 1998-2016: Epidemiology and outcomes

PURPOSE

To evaluate changes in the epidemiology of mechanical ventilation in Spain from 1998 to 2016.

DESIGN

A post hoc analysis of four cohort studies was carried out.

SETTING

A total of 138 Spanish ICUs.

PATIENTS

A sample of 4293 patients requiring invasive mechanical ventilation for more than 12h or noninvasive ventilation for more than 1h.

INTERVENTIONS

None.

VARIABLES OF INTEREST

Demographic variables, reason for mechanical ventilation, variables related to ventilatory support (ventilation mode, tidal volume, PEEP, airway pressures), complications during mechanical ventilation, duration of mechanical ventilation, ICU stay and ICU mortality.

RESULTS

There was an increase in severity (SAPSII: 43 points in 1998 vs. 47 points in 2016), changes in the reason for mechanical ventilation (decrease in chronic obstructive pulmonary disease and acute respiratory failure secondary to trauma, and increase in neurological disease and post-cardiac arrest). There was an increase in noninvasive mechanical ventilation as the first mode of ventilatory support (p<0.001). Volume control ventilation was the most commonly used mode, with increased support pressure and pressure-regulated volume-controlled ventilation. A decrease in tidal volume was observed (9ml/kg actual b.w. in 1998 and 6.6ml/kg in 2016; p<0.001) as well as an increase in PEEP (3cmH₂O in 1998 and 6cmH₂O in 2016; p<0.001). In-ICU mortality decreased (34% in 1998 and 27% in 2016; p<0.001), without geographical variability (median OR 1.43; p=0.258).

CONCLUSIONS

A significant decrease in mortality was observed in patients ventilated in Spanish ICUs. These changes in mortality could be related to modifications in ventilation strategy to minimize ventilator-induced lung injury.

Individualized Positive End-expiratory Pressure and Regional Gas Exchange in Porcine Lung Injury

Background

In acute respiratory failure elevated intraabdominal pressure aggravates lung collapse, tidal recruitment, and ventilation inhomogeneity. Low positive end-expiratory pressure (PEEP) may promote lung collapse and intrapulmonary shunting, whereas high PEEP may increase dead space by inspiratory overdistension. The authors hypothesized that an electrical impedance tomography–guided PEEP approach minimizing tidal recruitment improves regional ventilation and perfusion matching when compared to a table-based low PEEP/no recruitment and an oxygenation-guided high PEEP/full recruitment strategy in a hybrid model of lung injury and elevated intraabdominal pressure.

Methods

In 15 pigs with oleic acid–induced lung injury intraabdominal pressure was increased by intraabdominal saline infusion. PEEP was set in randomized order: (1) guided by a PEEP/inspired oxygen fraction table, without recruitment maneuver; (2) minimizing tidal recruitment guided by electrical impedance tomography after a recruitment maneuver; and (3) maximizing oxygenation after a recruitment maneuver. Single photon emission computed tomography was used to analyze regional ventilation, perfusion, and aeration. Primary outcome measures were differences in PEEP levels and regional ventilation/perfusion matching.

Results

Resulting PEEP levels were different (mean ± SD) with (1) table PEEP: 11 ± 3 cm H2O; (2) minimal tidal recruitment PEEP: 22 ± 3 cm H2O; and (3) maximal oxygenation PEEP: 25 ± 4 cm H2O; P &lt; 0.001. Table PEEP without recruitment maneuver caused highest lung collapse (28 ± 11% vs. 5 ± 5% vs. 4 ± 4%; P &lt; 0.001), shunt perfusion (3.2 ± 0.8 l/min vs. 1.0 ± 0.8 l/min vs. 0.7 ± 0.6 l/min; P &lt; 0.001) and dead space ventilation (2.9 ± 1.0 l/min vs. 1.5 ± 0.7 l/min vs. 1.7 ± 0.8 l/min; P &lt; 0.001). Although resulting in different PEEP levels, minimal tidal recruitment and maximal oxygenation PEEP, both following a recruitment maneuver, had similar effects on regional ventilation/perfusion matching.

Conclusions

When compared to table PEEP without a recruitment maneuver, both minimal tidal recruitment PEEP and maximal oxygenation PEEP following a recruitment maneuver decreased shunting and dead space ventilation, and the effects of minimal tidal recruitment PEEP and maximal oxygenation PEEP were comparable.

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