Feasibility of Continuous Infusion of Cefiderocol in Conjunction with the Establishment of Therapeutic Drug Monitoring in Patients with Extensively Drug-Resistant Gram-Negative Bacteria.

BACKGROUND AND OBJECTIVE: Resistance to antibacterial substances is a huge and still emerging issue, especially with regard to Gram-negative bacteria and in critically ill patients. We report a study in six patients infected with extensively drug-resistant Gram-negative bacteria in a limited outbreak who were successfully managed with a quasi-continuous infusion of cefiderocol. METHODS: Patients were initially treated with prolonged infusions of cefiderocol over 3 h every 8 h, and the application mode was then switched to a quasi-continuous infusion of 2 g over 8 h, i.e. 6 g in 24 h. Therapeutic drug monitoring (TDM) was established using an in-house liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. RESULTS: Determined trough plasma concentrations were a median of 50.00 mg/L [95% confidence interval (CI) 27.20, 74.60] and steady-state plasma concentrations were a median of 90.96 mg/L [95% CI 37.80, 124]. No significant differences were detected with respect to acute kidney injury/continuous renal replacement therapy. Plasma concentrations determined from different modes of storage were almost equal when frozen or cooled, but markedly reduced when stored at room temperature. CONCLUSIONS: (Quasi) continuous application of cefiderocol 6 g/24 h in conjunction with TDM is a feasible mode of application; the sample for TDM should either be immediately analyzed, cooled, or frozen prior to analysis.

Pathophysiology of COVID-19 pneumonia and respiratory treatment.

COVID-19 pandemic has seen an unprecedented number of patients presenting with acute respiratory distress syndrome to the intensive care units all over the world. Between August and November 2022, we performed research on PubMed screening all publications on COVID-19 disease and respiratory failure and its treatment. In this review we focused on COVID-19 most common manifestations concerning lung function. The respiratory infection develops in three broad phases: early, intermediate, and late. The mainstay of the disease is the frequent presence of severe hypoxemia associated - at least at the beginning - to a near normal lung mechanics and PaCO2 tension. The management of symptomatic patients, progressing through these temporal phases, is not possible without understanding the pathophysiology underlying the respiratory manifestation.

Janus kinase inhibitors for the treatment of COVID-19.

BACKGROUND: With potential antiviral and anti-inflammatory properties, Janus kinase (JAK) inhibitors represent a potential treatment for symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. They may modulate the exuberant immune response to SARS-CoV-2 infection. Furthermore, a direct antiviral effect has been described. An understanding of the current evidence regarding the efficacy and safety of JAK inhibitors as a treatment for coronavirus disease 2019 (COVID-19) is required. OBJECTIVES: To assess the effects of systemic JAK inhibitors plus standard of care compared to standard of care alone (plus/minus placebo) on clinical outcomes in individuals (outpatient or in-hospital) with any severity of COVID-19, and to maintain the currency of the evidence using a living systematic review approach. SEARCH METHODS: We searched the Cochrane COVID-19 Study Register (comprising MEDLINE, Embase, ClinicalTrials.gov, World Health Organization (WHO) International Clinical Trials Registry Platform, medRxiv, and Cochrane Central Register of Controlled Trials), Web of Science, WHO COVID-19 Global literature on coronavirus disease, and the US Department of Veterans Affairs Evidence Synthesis Program (VA ESP) Covid-19 Evidence Reviews to identify studies up to February 2022. We monitor newly published randomised controlled trials (RCTs) weekly using the Cochrane COVID-19 Study Register, and have incorporated all new trials from this source until the first week of April 2022. SELECTION CRITERIA: We included RCTs that compared systemic JAK inhibitors plus standard of care to standard of care alone (plus/minus placebo) for the treatment of individuals with COVID-19. We used the WHO definitions of illness severity for COVID-19. DATA COLLECTION AND ANALYSIS: We assessed risk of bias of primary outcomes using Cochrane's Risk of Bias 2 (RoB 2) tool. We used GRADE to rate the certainty of evidence for the following primary outcomes: all-cause mortality (up to day 28), all-cause mortality (up to day 60), improvement in clinical status: alive and without need for in-hospital medical care (up to day 28), worsening of clinical status: new need for invasive mechanical ventilation or death (up to day 28), adverse events (any grade), serious adverse events, secondary infections. MAIN RESULTS: We included six RCTs with 11,145 participants investigating systemic JAK inhibitors plus standard of care compared to standard of care alone (plus/minus placebo). Standard of care followed local protocols and included the application of glucocorticoids (five studies reported their use in a range of 70% to 95% of their participants; one study restricted glucocorticoid use to non-COVID-19 specific indications), antibiotic agents, anticoagulants, and antiviral agents, as well as non-pharmaceutical procedures. At study entry, about 65% of participants required low-flow oxygen, about 23% required high-flow oxygen or non-invasive ventilation, about 8% did not need any respiratory support, and only about 4% were intubated. We also identified 13 ongoing studies, and 9 studies that are completed or terminated and where classification is pending. Individuals with moderate to severe disease Four studies investigated the single agent baricitinib (10,815 participants), one tofacitinib (289 participants), and one ruxolitinib (41 participants). Systemic JAK inhibitors probably decrease all-cause mortality at up to day 28 (95 of 1000 participants in the intervention group versus 131 of 1000 participants in the control group; risk ratio (RR) 0.72, 95% confidence interval (CI) 0.57 to 0.91; 6 studies, 11,145 participants; moderate-certainty evidence), and decrease all-cause mortality at up to day 60 (125 of 1000 participants in the intervention group versus 181 of 1000 participants in the control group; RR 0.69, 95% CI 0.56 to 0.86; 2 studies, 1626 participants; high-certainty evidence). Systemic JAK inhibitors probably make little or no difference in improvement in clinical status (discharged alive or hospitalised, but no longer requiring ongoing medical care) (801 of 1000 participants in the intervention group versus 778 of 1000 participants in the control group; RR 1.03, 95% CI 1.00 to 1.06; 4 studies, 10,802 participants; moderate-certainty evidence). They probably decrease the risk of worsening of clinical status (new need for invasive mechanical ventilation or death at day 28) (154 of 1000 participants in the intervention group versus 172 of 1000 participants in the control group; RR 0.90, 95% CI 0.82 to 0.98; 2 studies, 9417 participants; moderate-certainty evidence). Systemic JAK inhibitors probably make little or no difference in the rate of adverse events (any grade) (427 of 1000 participants in the intervention group versus 441 of 1000 participants in the control group; RR 0.97, 95% CI 0.88 to 1.08; 3 studies, 1885 participants; moderate-certainty evidence), and probably decrease the occurrence of serious adverse events (160 of 1000 participants in the intervention group versus 202 of 1000 participants in the control group; RR 0.79, 95% CI 0.68 to 0.92; 4 studies, 2901 participants; moderate-certainty evidence). JAK inhibitors may make little or no difference to the rate of secondary infection (111 of 1000 participants in the intervention group versus 113 of 1000 participants in the control group; RR 0.98, 95% CI 0.89 to 1.09; 4 studies, 10,041 participants; low-certainty evidence). Subgroup analysis by severity of COVID-19 disease or type of JAK inhibitor did not identify specific subgroups which benefit more or less from systemic JAK inhibitors. Individuals with asymptomatic or mild disease We did not identify any trial for this population. AUTHORS' CONCLUSIONS: In hospitalised individuals with moderate to severe COVID-19, moderate-certainty evidence shows that systemic JAK inhibitors probably decrease all-cause mortality. Baricitinib was the most often evaluated JAK inhibitor. Moderate-certainty evidence suggests that they probably make little or no difference in improvement in clinical status. Moderate-certainty evidence indicates that systemic JAK inhibitors probably decrease the risk of worsening of clinical status and make little or no difference in the rate of adverse events of any grade, whilst they probably decrease the occurrence of serious adverse events. Based on low-certainty evidence, JAK inhibitors may make little or no difference in the rate of secondary infection. Subgroup analysis by severity of COVID-19 or type of agent failed to identify specific subgroups which benefit more or less from systemic JAK inhibitors. Currently, there is no evidence on the efficacy and safety of systemic JAK inhibitors for individuals with asymptomatic or mild disease (non-hospitalised individuals).

The SARS-CoV-2 Delta-Omicron Recombinant Lineage (XD) Exhibits Immune-Escape Properties Similar to the Omicron (BA.1) Variant.

Recently, a recombinant SARS-CoV-2 lineage, XD, emerged that harbors a spike gene that is largely derived from the Omicron variant BA.1 in the genetic background of the Delta variant. This finding raised concerns that the recombinant virus might exhibit altered biological properties as compared to the parental viruses and might pose an elevated threat to human health. Here, using pseudotyped particles, we show that ACE2 binding and cell tropism of XD mimics that of BA.1. Further, XD and BA.1 displayed comparable sensitivity to neutralization by antibodies induced upon vaccination with BNT162b2/Comirnaty (BNT) or BNT vaccination followed by breakthrough infection. Our findings reveal important biological commonalities between XD and Omicron BA.1 host cell entry and its inhibition by antibodies.

High class filtering facepiece (FFP) are fundamental and effective in protection of emergency health care workers: an observational cohort study in a German community.

BACKGROUND: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a highly contagious airborne virus inducing pandemic coronavirus disease 2019 (COVID-19). This is most relevant for medical staff working under harmful conditions in emergencies often dealing with patients and an undefined SARS-CoV-2 status. We aimed to measure the effect of high-class filtering facepieces (FFP) in emergency medical service (EMS) staff by analyzing seroprevalence and history of positive polymerase chain reaction (PCR) for SARS-CoV-2. METHOD: This observational cohort study included workers in EMS, who were compared with hospital staff (HS) and staff, which was not directly involved in patient care (NPC). All direct patient contacts of EMS workers were protected by FFP2/N95 (filtering face piece protection class 2/non-oil-based particulates filter efficiency 95%) masks, whereas HS was protected by FFP2/N95 exclusively when a patient had a proven or suspected SARS-CoV-2 infection. NPC was not protected by higher FFP. The seroprevalence of SARS-CoV-2 antibodies was analyzed by immunoassay by end of 12/2020 together with the history of a positive PCR. In addition, a self-assessment was performed regarding the quantity of SARS-CoV-2 positive contacts, about flu symptoms and personal belief of previous COVID-19 infections. RESULTS: The period in which contact to SARS-CoV-2 positive patients has been possible was 10 months (March to December 2020)-with 54,681 patient contacts documented for EMS-either emergencies (n = 33,241) or transportation services (n = 21,440). Seven hundred-thirty (n = 730) participants were included into the study (n = EMS: 325, HS: 322 and NPC: 83). The analysis of the survey showed that the exposure to patients with an unknown and consecutive positive SARS-CoV-2 result was significantly higher for EMS when compared to HS (EMS 55% vs. HS 30%, p = 0.01). The incidence of a SARS-CoV-2 infection in our cohort was 1.2% (EMS), 2.2% (HS) and 2.4% (NPC) within the three groups (ns) and lowest in EMS. Furthermore, the belief of previous COVID-19 was significant higher in EMS (19% vs. 10%), CONCLUSION: The consistent use of FFP2/N95 in EMS is able to prevent work-related SARS-CoV-2 infections in emergency situations. The significance of physical airway protection in exposed medical staff is still relevant especially under the aspect of new viral variants and unclear effectiveness of new vaccines.

COVID-19 Intensive Care-Evaluation of Public Information Sources and Current Standards of Care in German Intensive Care Units: A Cross Sectional Online Survey on Intensive Care Staff in Germany.

Backround: In February 2021, the first formal evidence and consensus-based (S3) guidelines for the inpatient treatment of patients with COVID-19 were published in Germany and have been updated twice during 2021. The aim of the present study is to re-evaluate the dissemination pathways and strategies for ICU staff (first evaluation in December 2020 when previous versions of consensus-based guidelines (S2k) were published) and question selected aspects of guideline adherence of standard care for patients with COVID-19 in the ICU. Methods: We conducted an anonymous online survey among German intensive care staff from 11 October 2021 to 11 November 2021. We distributed the survey via e-mail in intensive care facilities and requested redirection to additional intensive care staff (snowball sampling). Results: There was a difference between the professional groups in the number, selection and qualitative assessment of information sources about COVID-19. Standard operating procedures were most frequently used by all occupational groups and received a high quality rating. Physicians preferred sources for active information search (e.g., medical journals), while nurses predominantly used passive consumable sources (e.g., every-day media). Despite differences in usage behaviour, the sources were rated similarly in terms of the quality of the information on COVID-19. The trusted organizations have not changed over time. The use of guidelines was frequently stated and highly recommended. The majority of the participants reported guideline-compliant treatment. Nevertheless, there were certain variations in the use of medication as well as the criteria chosen for discontinuing non-invasive ventilation (NIV) compared to guideline recommendations. Conclusions: An adequate external source of information for nursing staff is lacking, the usual sources of physicians are only appropriate for the minority of nursing staff. The self-reported use of guidelines is high.

Key characteristics impacting survival of COVID-19 extracorporeal membrane oxygenation.

BACKGROUND: Severe COVID-19 induced acute respiratory distress syndrome (ARDS) often requires extracorporeal membrane oxygenation (ECMO). Recent German health insurance data revealed low ICU survival rates. Patient characteristics and experience of the ECMO center may determine intensive care unit (ICU) survival. The current study aimed to identify factors affecting ICU survival of COVID-19 ECMO patients. METHODS: 673 COVID-19 ARDS ECMO patients treated in 26 centers between January 1st 2020 and March 22nd 2021 were included. Data on clinical characteristics, adjunct therapies, complications, and outcome were documented. Block wise logistic regression analysis was applied to identify variables associated with ICU-survival. RESULTS: Most patients were between 50 and 70 years of age. PaO2/FiO2 ratio prior to ECMO was 72 mmHg (IQR: 58-99). ICU survival was 31.4%. Survival was significantly lower during the 2nd wave of the COVID-19 pandemic. A subgroup of 284 (42%) patients fulfilling modified EOLIA criteria had a higher survival (38%) (p = 0.0014, OR 0.64 (CI 0.41-0.99)). Survival differed between low, intermediate, and high-volume centers with 20%, 30%, and 38%, respectively (p = 0.0024). Treatment in high volume centers resulted in an odds ratio of 0.55 (CI 0.28-1.02) compared to low volume centers. Additional factors associated with survival were younger age, shorter time between intubation and ECMO initiation, BMI > 35 (compared to < 25), absence of renal replacement therapy or major bleeding/thromboembolic events. CONCLUSIONS: Structural and patient-related factors, including age, comorbidities and ECMO case volume, determined the survival of COVID-19 ECMO. These factors combined with a more liberal ECMO indication during the 2nd wave may explain the reasonably overall low survival rate. Careful selection of patients and treatment in high volume ECMO centers was associated with higher odds of ICU survival. TRIAL REGISTRATION: Registered in the German Clinical Trials Register (study ID: DRKS00022964, retrospectively registered, September 7th 2020, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00022964 .

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.

End-Tidal to Arterial Pco2 Ratio as Guide to Weaning from Venovenous Extracorporeal Membrane Oxygenation.

Rationale: Weaning from venovenous extracorporeal membrane oxygenation (VV-ECMO) is based on oxygenation and not on carbon dioxide elimination. Objectives: To predict readiness to wean from VV-ECMO. Methods: In this multicenter study of mechanically ventilated adults with severe acute respiratory distress syndrome receiving VV-ECMO, we investigated a variable based on CO2 elimination. The study included a prospective interventional study of a physiological cohort (n = 26) and a retrospective clinical cohort (n = 638). Measurements and Main Results: Weaning failure in the clinical and physiological cohorts were 37% and 42%, respectively. The main cause of failure in the physiological cohort was high inspiratory effort or respiratory rate. All patients exhaled similar amounts of CO2, but in patients who failed the weaning trial, [Formula: see text]e was higher to maintain the PaCO2 unchanged. The effort to eliminate one unit-volume of CO2, was double in patients who failed (68.9 [42.4-123] vs. 39 [20.1-57] cm H2O/[L/min]; P = 0.007), owing to the higher physiological Vd (68 [58.73] % vs. 54 [41.64] %; P = 0.012). End-tidal partial carbon dioxide pressure (PetCO2)/PaCO2 ratio was a clinical variable strongly associated with weaning outcome at baseline, with area under the receiver operating characteristic curve of 0.87 (95% confidence interval [CI], 0.71-1). Similarly, the PetCO2/PaCO2 ratio was associated with weaning outcome in the clinical cohort both before the weaning trial (odds ratio, 4.14; 95% CI, 1.32-12.2; P = 0.015) and at a sweep gas flow of zero (odds ratio, 13.1; 95% CI, 4-44.4; P < 0.001). Conclusions: The primary reason for weaning failure from VV-ECMO is high effort to eliminate CO2. A higher PetCO2/PaCO2 ratio was associated with greater likelihood of weaning from VV-ECMO.

[COVID-19 pandemic: preferences and barriers for dissemination of evidence syntheses : Survey of intensive care personnel in Germany]. / COVID-19-Pandemie: Präferenzen und Barrieren für die Disseminierung von Evidenzsynthesen : Befragung des intensivmedizinischen Personals in Deutschland.

BACKGROUND: In the context of COVID-19, the German CEOsys project (COVID-19 Evidenz Ökosystem, www.covid-evidenz.de ) identifies, evaluates and summarizes the results of scientific studies to obtain evidence on this disease. The evidence syntheses are used to derive specific recommendations for clinical practice and to contribute to national guidelines. Besides the necessity of conducting good quality evidence syntheses during a pandemic, just as important is that the dissemination of evidence needs to be quick and efficient, especially in a health crisis. The CEOsys project has set itself this challenge. OBJECTIVE: Preparing the most suitable distribution of evidence syntheses as part of the CEOsys project tasks. METHODS: Intensive care unit (ICU) personnel in Germany were surveyed via categorical and free text questions. The survey focused on the following topics: evidence syntheses, channels and strategies of distribution, possibility of feedback, structure and barriers of dissemination and trustworthiness of various organizations. Profession, qualification, setting and size of the facility were recorded. Questionnaires were pretested throughout the queried professions (physician, nurse, others). The survey was anonymously carried out online through SosciSurvey® and an e­mail was sent directly to 940 addresses. The survey was launched on 3 December, a reminder was sent after 14 days and it ended on 31 December. The survey was also announced via e­mail through DIVI. RESULTS: Of 317 respondents 200 completed the questionnaire. All information was analyzed including the responses from incomplete questionnaires. The most stated barriers were lack of time and access. Especially residents and nurses without specialization in intensive care mentioned uncertainty or insufficient experience in dealing with evidence syntheses as a barrier. Active distribution of evidence syntheses was clearly preferred. More than half of the participants chose websites of public institutions, medical journals, professional societies and e­mail newsletters for drawing attention to new evidence syntheses. Short versions, algorithms and webinars were the most preferred strategies for dissemination. Trust in organizations supplying information on the COVID-19 pandemic was given to professional societies and the Robert Koch Institute (RKI) as the German governmental institute for infections and public health. The respondents' prioritized topics are long-term consequences of the disease, protection of medical personnel against infection and possibilities of ventilation treatment. CONCLUSION: Even though universally valid, evidence syntheses should be actively brought to the target audience, especially during a health crisis such as the COVID-19 pandemic with its exceptional challenges including lack of time and uncertainties in patient care. The contents should be clear, short (short versions, algorithms) and with free access. E­mail newsletters, websites or medical journals should continuously report on new evidence syntheses. Professional societies and the governmental institute for infections and public health should be involved in dissemination due to their obvious trustworthiness.

Activation of Sphingomyelinase-Ceramide-Pathway in COVID-19 Purposes Its Inhibition for Therapeutic Strategies.

Effective treatment strategies for severe coronavirus disease (COVID-19) remain scarce. Hydrolysis of membrane-embedded, inert sphingomyelin by stress responsive sphingomyelinases is a hallmark of adaptive responses and cellular repair. As demonstrated in experimental and observational clinical studies, the transient and stress-triggered release of a sphingomyelinase, SMPD1, into circulation and subsequent ceramide generation provides a promising target for FDA-approved drugs. Here, we report the activation of sphingomyelinase-ceramide pathway in 23 intensive care patients with severe COVID-19. We observed an increase of circulating activity of sphingomyelinase with subsequent derangement of sphingolipids in serum lipoproteins and from red blood cells (RBC). Consistent with increased ceramide levels derived from the inert membrane constituent sphingomyelin, increased activity of acid sphingomyelinase (ASM) accurately distinguished the patient cohort undergoing intensive care from healthy controls. Positive correlational analyses with biomarkers of severe clinical phenotype support the concept of an essential pathophysiological role of ASM in the course of SARS-CoV-2 infection as well as of a promising role for functional inhibition with anti-inflammatory agents in SARS-CoV-2 infection as also proposed in independent observational studies. We conclude that large-sized multicenter, interventional trials are now needed to evaluate the potential benefit of functional inhibition of this sphingomyelinase in critically ill patients with COVID-19.

Erythrocytes increase endogenous sphingosine 1-phosphate levels as an adaptive response to SARS-CoV-2 infection.

Low plasma levels of the signaling lipid metabolite sphingosine 1-phosphate (S1P) are associated with disrupted endothelial cell (EC) barriers, lymphopenia and reduced responsivity to hypoxia. Total S1P levels were also reduced in 23 critically ill patients with coronavirus disease 2019 (COVID-19), and the two main S1P carriers, serum albumin (SA) and high-density lipoprotein (HDL) were dramatically low. Surprisingly, we observed a carrier-changing shift from SA to HDL, which probably prevented an even further drop in S1P levels. Furthermore, intracellular S1P levels in red blood cells (RBCs) were significantly increased in COVID-19 patients compared with healthy controls due to up-regulation of S1P producing sphingosine kinase 1 and down-regulation of S1P degrading lyase expression. Cell culture experiments supported increased sphingosine kinase activity and unchanged S1P release from RBC stores of COVID-19 patients. These observations suggest adaptive mechanisms for maintenance of the vasculature and immunity as well as prevention of tissue hypoxia in COVID-19 patients.

A Comparison and Evaluation of International Guidelines on the Treatment of Severe SARS-CoV-2 Infection.

BACKGROUND: When the SARS-CoV-2 pandemic began, no uniform treatment and care strategies for critically ill COVID-19 patients were yet available. National and international treatment recommendations were formulated under time pressure, initially on the basis of indirect evidence from the treatment of similar diseases. In this article, we give an overview of the content, currency, and methodological quality of the existing national and international guidelines, with special attention to the care of critically ill patients. METHODS: Guidelines were identified by a comprehensive search, the included guidelines were assessed in standardized fashion with the AGREE II guideline assessment instrument and according to the AMWF rulebook criteria, and the core recommendations of the included and methodologically high-quality guidelines were compared. RESULTS: Nine of the 97 guidelines that were identified fulfilled the content criteria for inclusion, and 6 of these fulfilled the qualitative criteria; these 6 guidelines still differed, however, in the topics to which they devoted the most attention, as well as in their methodological quality and currency. The treatment strategies for patients with severe respiratory failure (lung-protective ventilation strategies and rescue measures) deviated little from established standards. Uniform recommendations were made, among other things, for the administration of dexamethasone, which was recommended in all of the guidelines for patients requiring oxygen treatment, as well as for antithrombotic drug prophylaxis and for the prone positioning of ventilated patients. Many recommendations were based on insufficient evidence, and some were contradictory, e.g., those regarding antibiotic treatment or the choice between high-flow oxygen administration via nasal canula (HFNC) and noninvasive ventilation (NIV). CONCLUSION: The consultation of multiple high-quality international guidelines and guideline recommendations shared in online portals such as MagicApp are helpful sources of information for clinicians. In view of the continuing lack of strong evidence, further research on intensive care treatments is needed (aspects of ventilation, positioning therapy, and the role of extracorporeal membrane oxygenation [ECMO]).

Case Report: Interferon- γ Rescues Monocytic Human Leukocyte Antigen Receptor (mHLA-DR) Function in a COVID-19 Patient With ARDS and Superinfection With Multiple MDR 4MRGN Bacterial Strains.

Background: CD14+ monocytes present antigens to adaptive immune cells via monocytic human leukocyte antigen receptor (mHLA-DR), which is described as an immunological synapse. Reduced levels of mHLA-DR can display an acquired immune defect, which is often found in sepsis and predisposes for secondary infections and fatal outcomes. Monocytic HLA-DR expression is reliably induced by interferon- γ (IFNγ) therapy. Case Report: We report a case of multidrug-resistant superinfected COVID-19 acute respiratory distress syndrome (ARDS) on extracorporeal membrane oxygenation (ECMO) support. The resistance profiles of the detected Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii and Citrobacter freundii isolates were equipped with resistance to all four antibiotic classes including carbapenems (4MRGN) and Cefiderocol in the case of K. pneumoniae. A causal therapeutic antibiotic strategy was not available. Therefore, we measured the immune status of the patient aiming to identify a potential acquired immune deficiency. Monocyte HLA-DR expression identified by FACS analysis revealed an expression level of 34% positive monocytes and suggested severe immunosuppression. We indicated IFNγ therapy, which resulted in a rapid increase in mHLA-DR expression (96%), rapid resolution of invasive bloodstream infection, and discharge from the hospital on day 70. Discussion: Superinfection is a dangerous complication of COVID-19 pneumonia, and sepsis-induced immunosuppression is a risk factor for it. Immunosuppression is expressed by a disturbed antigen presentation of monocytes to cells of the adaptive immune system. The case presented here is remarkable as no validated antibiotic regimen existed against the detected bacterial pathogens causing bloodstream infection and severe pneumonia in a patient suffering from COVID-19 ARDS. Possible restoration of the patient's own immunity by IFNγ was a plausible option to boost the patient's immune system, eliminate the identified 4MRGNs, and allow for lung recovery. This led to the conclusion that immune status monitoring is useful in complicated COVID-19-ARDS and that concomitant IFNγ therapy may support antibiotic strategies. Conclusion: After a compromised immune system has been detected by suppressed mHLA-DR levels, the immune system can be safely reactivated by IFNγ.

Using Artificial Intelligence for Automatic Segmentation of CT Lung Images in Acute Respiratory Distress Syndrome.

Knowledge of gas volume, tissue mass and recruitability measured by the quantitative CT scan analysis (CT-qa) is important when setting the mechanical ventilation in acute respiratory distress syndrome (ARDS). Yet, the manual segmentation of the lung requires a considerable workload. Our goal was to provide an automatic, clinically applicable and reliable lung segmentation procedure. Therefore, a convolutional neural network (CNN) was used to train an artificial intelligence (AI) algorithm on 15 healthy subjects (1,302 slices), 100 ARDS patients (12,279 slices), and 20 COVID-19 (1,817 slices). Eighty percent of this populations was used for training, 20% for testing. The AI and manual segmentation at slice level were compared by intersection over union (IoU). The CT-qa variables were compared by regression and Bland Altman analysis. The AI-segmentation of a single patient required 5-10 s vs. 1-2 h of the manual. At slice level, the algorithm showed on the test set an IOU across all CT slices of 91.3 ± 10.0, 85.2 ± 13.9, and 84.7 ± 14.0%, and across all lung volumes of 96.3 ± 0.6, 88.9 ± 3.1, and 86.3 ± 6.5% for normal lungs, ARDS and COVID-19, respectively, with a U-shape in the performance: better in the lung middle region, worse at the apex and base. At patient level, on the test set, the total lung volume measured by AI and manual segmentation had a R 2 of 0.99 and a bias -9.8 ml [CI: +56.0/-75.7 ml]. The recruitability measured with manual and AI-segmentation, as change in non-aerated tissue fraction had a bias of +0.3% [CI: +6.2/-5.5%] and -0.5% [CI: +2.3/-3.3%] expressed as change in well-aerated tissue fraction. The AI-powered lung segmentation provided fast and clinically reliable results. It is able to segment the lungs of seriously ill ARDS patients fully automatically.

Addressing the 'hypoxia paradox' in severe COVID-19: literature review and report of four cases treated with erythropoietin analogues.

BACKGROUND: Since fall 2019, SARS-CoV-2 spread world-wide, causing a major pandemic with estimated ~ 220 million subjects affected as of September 2021. Severe COVID-19 is associated with multiple organ failure, particularly of lung and kidney, but also grave neuropsychiatric manifestations. Overall mortality reaches > 2%. Vaccine development has thrived in thus far unreached dimensions and will be one prerequisite to terminate the pandemic. Despite intensive research, however, few treatment options for modifying COVID-19 course/outcome have emerged since the pandemic outbreak. Additionally, the substantial threat of serious downstream sequelae, called 'long COVID' and 'neuroCOVID', becomes increasingly evident. Among candidates that were suggested but did not yet receive appropriate funding for clinical trials is recombinant human erythropoietin. Based on accumulating experimental and clinical evidence, erythropoietin is expected to (1) improve respiration/organ function, (2) counteract overshooting inflammation, (3) act sustainably neuroprotective/neuroregenerative. Recent counterintuitive findings of decreased serum erythropoietin levels in severe COVID-19 not only support a relative deficiency of erythropoietin in this condition, which can be therapeutically addressed, but also made us coin the term 'hypoxia paradox'. As we review here, this paradox is likely due to uncoupling of physiological hypoxia signaling circuits, mediated by detrimental gene products of SARS-CoV-2 or unfavorable host responses, including microRNAs or dysfunctional mitochondria. Substitution of erythropoietin might overcome this 'hypoxia paradox' caused by deranged signaling and improve survival/functional status of COVID-19 patients and their long-term outcome. As supporting hints, embedded in this review, we present 4 male patients with severe COVID-19 and unfavorable prognosis, including predicted high lethality, who all profoundly improved upon treatment which included erythropoietin analogues. SHORT CONCLUSION: Substitution of EPO may-among other beneficial EPO effects in severe COVID-19-circumvent downstream consequences of the 'hypoxia paradox'. A double-blind, placebo-controlled, randomized clinical trial for proof-of-concept is warranted.