Machine learning links unresolving secondary pneumonia to mortality in patients with severe pneumonia, including COVID-19.

BACKGROUNDDespite guidelines promoting the prevention and aggressive treatment of ventilator-associated pneumonia (VAP), the importance of VAP as a driver of outcomes in mechanically ventilated patients, including patients with severe COVID-19, remains unclear. We aimed to determine the contribution of unsuccessful treatment of VAP to mortality for patients with severe pneumonia.METHODSWe performed a single-center, prospective cohort study of 585 mechanically ventilated patients with severe pneumonia and respiratory failure, 190 of whom had COVID-19, who underwent at least 1 bronchoalveolar lavage. A panel of intensive care unit (ICU) physicians adjudicated the pneumonia episodes and endpoints on the basis of clinical and microbiological data. Given the relatively long ICU length of stay (LOS) among patients with COVID-19, we developed a machine-learning approach called CarpeDiem, which grouped similar ICU patient-days into clinical states based on electronic health record data.RESULTSCarpeDiem revealed that the long ICU LOS among patients with COVID-19 was attributable to long stays in clinical states characterized primarily by respiratory failure. While VAP was not associated with mortality overall, the mortality rate was higher for patients with 1 episode of unsuccessfully treated VAP compared with those with successfully treated VAP (76.4% versus 17.6%, P < 0.001). For all patients, including those with COVID-19, CarpeDiem demonstrated that unresolving VAP was associated with a transitions to clinical states associated with higher mortality.CONCLUSIONSUnsuccessful treatment of VAP is associated with higher mortality. The relatively long LOS for patients with COVID-19 was primarily due to prolonged respiratory failure, placing them at higher risk of VAP.FUNDINGNational Institute of Allergy and Infectious Diseases (NIAID), NIH grant U19AI135964; National Heart, Lung, and Blood Institute (NHLBI), NIH grants R01HL147575, R01HL149883, R01HL153122, R01HL153312, R01HL154686, R01HL158139, P01HL071643, and P01HL154998; National Heart, Lung, and Blood Institute (NHLBI), NIH training grants T32HL076139 and F32HL162377; National Institute on Aging (NIA), NIH grants K99AG068544, R21AG075423, and P01AG049665; National Library of Medicine (NLM), NIH grant R01LM013337; National Center for Advancing Translational Sciences (NCATS), NIH grant U01TR003528; Veterans Affairs grant I01CX001777; Chicago Biomedical Consortium grant; Northwestern University Dixon Translational Science Award; Simpson Querrey Lung Institute for Translational Science (SQLIFTS); Canning Thoracic Institute of Northwestern Medicine.

Clinical Features of COVID-19 and Differentiation from Other Causes of CAP.

Community-acquired pneumonia (CAP) is a significant cause of morbidity and mortality, one of the most common reasons for infection-related death worldwide. Causes of CAP include numerous viral, bacterial, and fungal pathogens, though frequently no specific organism is found. Beginning in 2019, the COVID-19 pandemic has caused incredible morbidity and mortality. COVID-19 has many features typical of CAP such as fever, respiratory distress, and cough, and can be difficult to distinguish from other types of CAP. Here, we highlight unique clinical features of COVID-19 pneumonia such as olfactory and gustatory dysfunction, lymphopenia, and distinct imaging appearance.

Obesity Is Associated with Attenuated Tissue Immunity in COVID-19.

RATIONALE: Obesity affects 40% of US adults, is associated with a pro-inflammatory state, and presents a significant risk factor for the development of severe COVID-19. To date, there is limited information on how obesity might affect immune cell responses in SARS-CoV-2 infection. OBJECTIVES: To determine the impact of obesity on respiratory tract immunity in COVID-19 across human lifespan. METHODS: We analysed single cell transcriptomes from bronchiolar lavage in three ventilated adult cohorts with (n=24) or without COVID-19 (n=9), from nasal immune cells in children with (n=14) or without COVID-19 (n=19), and from peripheral blood mononuclear cells in an independent adult COVID-19 cohort (n=42), comparing obese (Ob) and non-obese subjects (N-Ob). MEASUREMENTS AND MAIN RESULTS: Surprisingly, we found that adult Ob subjects had attenuated lung immune/inflammatory responses in SARS-CoV-2 infection, with decreased expression of interferon (IFN)α, IFNγ and tumour necrosis factor (TNF) alpha response gene signatures in almost all lung epithelial and immune cell subsets, and lower expression of IFNG and TNF in specific lung immune cells. Peripheral blood immune cells in an independent adult cohort showed a similar, but less marked, reduction in type I IFN and IFNγ response genes, as well as decreased serum IFNα in Ob patients with SARS-CoV-2. Nasal immune cells from Ob children with COVID-19 also showed reduced enrichment of IFNα and IFNγ response genes. CONCLUSIONS: These findings show blunted tissue immune responses in Ob COVID-19 patients, with implications for treatment stratification, supporting the specific application of inhaled recombinant type I IFNs in this vulnerable subset. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Outcomes of Percutaneous Tracheostomy for Patients With SARS-CoV-2 Respiratory Failure.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause severe respiratory failure leading to prolonged mechanical ventilation. Data are just emerging about the practice and outcomes of tracheostomy in these patients. We reviewed our experience with tracheostomies for SARS-CoV-2. METHODS: We retrospectively reviewed the demographics, comorbidities, timing of mechanical ventilation, tracheostomy, and intensive care unit and hospital lengths of stay in SARS-CoV-2 patients who received tracheostomies performed by the interventional pulmonary team. A tertiary care, teaching hospital in Chicago, Illinois. From March 2020 to April 2021, our center had 473 patients intubated for SARS-CoV-2, and 72 (15%) had percutaneous bedside tracheostomy performed by the interventional pulmonary team. RESULTS: Median time from intubation to tracheostomy was 20 (interquartile range: 16 to 25) days. Demographics and comorbidities were similar between early and late tracheostomy, but early tracheostomy was associated with shorter intensive care unit lengths of stay and a shorter total duration of ventilation. To date, 39 (54%) patients have been decannulated, 17 (24%) before hospital discharge; median time to decannulation was 22 (IQR: 18 to 36) days. Patients that were decannulated were younger (56 vs. 69 y). The rate of decannulation for survivors was 82%. No providers developed symptoms or tested positive for SARS-CoV-2. CONCLUSION: Tracheostomy enhances care for patients with prolonged respiratory failure from SARS-CoV-2 since early tracheostomy is associated with shorter duration of critical care, and decannulation rates are high for survivors. It furthermore appears safe for both patients and operators.

Anthropomorphic Character Animations Versus Digital Chalk Talks in a Resident Diabetes Pharmacotherapy Curriculum: a Randomized Controlled Trial.

BACKGROUND: Animation in medical education has boomed over the past two decades, and demand for distance learning technologies will likely continue in the context of the COVID-19 pandemic. However, experimental data guiding best practices for animation in medical education are scarce. OBJECTIVE: To compare the efficacy of two animated video styles in a diabetes pharmacotherapy curriculum for internal medicine residents. DESIGN: Learners were randomized to receive one of two versions of the same multimodal didactic curriculum. They received identical lectures, group activities, and quizzes, but were randomized to either digital chalk talk (DCT) videos or Sugar-Coated Science (SCS). SCS is an animated series using anthropomorphic characters, stories, and mnemonics to communicate knowledge. PARTICIPANTS: Ninety-two internal medicine residents at a single academic medical center received the curriculum within ambulatory medicine didactics. MAIN MEASURES: Knowledge was measured at multiple time points, as was residents' self-reported comfort using each medication class covered. Surveys assessed video acceptability and telepresence. Key themes were identified from open-ended feedback. KEY RESULTS: Baseline knowledge was low, consistent with prior needs assessments. On immediate posttest, mean scores were higher with SCS than DCT (74.8% versus 68.4%), but the difference was not statistically significant, p = 0.10. Subgroup analyses revealed increased knowledge in the SCS group for specific medication classes. Delayed posttest showed significant knowledge gains averaging 17.6% across all participants (p < 0.05); these gains were similar between animation types. SCS achieved significantly higher telepresence, entertainment, and acceptability scores than DCT. Qualitative data suggested that residents prioritize well-designed, multimodal curricula over specific animation characteristics. CONCLUSION: SCS and DCTs both led to learning within a multimodal curriculum, but SCS significantly enhanced learner experience. Animation techniques exemplified by both SCS and DCTs have roles in the medical educator toolkit. Selection between them should incorporate context, learner factors, and production resources.

Gearing up for battle: Harnessing adaptive T cell immunity against gram-negative pneumonia.

Pneumonia is one of the leading causes of morbidity and mortality worldwide and Gram-negative bacteria are a major cause of severe pneumonia. Despite advances in diagnosis and treatment, the rise of multidrug-resistant organisms and hypervirulent strains demonstrates that there will continue to be challenges with traditional treatment strategies using antibiotics. Hence, an alternative approach is to focus on the disease tolerance components that mediate immune resistance and enhance tissue resilience. Adaptive immunity plays a pivotal role in modulating these processes, thus affecting the incidence and severity of pneumonia. In this review, we focus on the adaptive T cell responses to pneumonia induced by Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. We highlight key factors in these responses that have potential for therapeutic targeting, as well as the gaps in current knowledge to be focused on in future work.

Local and systemic responses to SARS-CoV-2 infection in children and adults.

It is not fully understood why COVID-19 is typically milder in children1-3. Here, to examine the differences between children and adults in their response to SARS-CoV-2 infection, we analysed paediatric and adult patients with COVID-19 as well as healthy control individuals (total n = 93) using single-cell multi-omic profiling of matched nasal, tracheal, bronchial and blood samples. In the airways of healthy paediatric individuals, we observed cells that were already in an interferon-activated state, which after SARS-CoV-2 infection was further induced especially in airway immune cells. We postulate that higher paediatric innate interferon responses restrict viral replication and disease progression. The systemic response in children was characterized by increases in naive lymphocytes and a depletion of natural killer cells, whereas, in adults, cytotoxic T cells and interferon-stimulated subpopulations were significantly increased. We provide evidence that dendritic cells initiate interferon signalling in early infection, and identify epithelial cell states associated with COVID-19 and age. Our matching nasal and blood data show a strong interferon response in the airways with the induction of systemic interferon-stimulated populations, which were substantially reduced in paediatric patients. Together, we provide several mechanisms that explain the milder clinical syndrome observed in children.

Prominent rash and multisystem inflammatory syndrome in a 29-year-old patient with COVID-19: a case report.

BACKGROUND: Adult patients with coronavirus disease present primarily with respiratory symptoms, but children and some adults may display a more systemic inflammatory syndrome with rash, fever, mucosal changes, and elevated inflammatory biomarkers. CASE PRESENTATION: Here, we report the case of a 29-year-old Hispanic patient presenting with significant rash and multisystem inflammation. We describe his clinical course, review dermatological manifestations of coronavirus disease, and summarize the pathophysiology of coronavirus disease-associated multisystem inflammation. CONCLUSION: This case should alert physicians to the atypical nature of presenting rash with minimal respiratory symptoms in coronavirus disease.

Bacterial Superinfection Pneumonia in Patients Mechanically Ventilated for COVID-19 Pneumonia.

Rationale: Current guidelines recommend patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia receive empirical antibiotics for suspected bacterial superinfection on the basis of weak evidence. Rates of ventilator-associated pneumonia (VAP) in clinical trials of patients with SARS-CoV-2 pneumonia are unexpectedly low. Objectives: We conducted an observational single-center study to determine the prevalence and etiology of bacterial superinfection at the time of initial intubation and the incidence and etiology of subsequent bacterial VAP in patients with severe SARS-CoV-2 pneumonia. Methods: Bronchoscopic BAL fluid samples from all patients with SARS-CoV-2 pneumonia requiring mechanical ventilation were analyzed using quantitative cultures and a multiplex PCR panel. Actual antibiotic use was compared with guideline-recommended therapy. Measurements and Main Results: We analyzed 386 BAL samples from 179 patients with SARS-CoV-2 pneumonia requiring mechanical ventilation. Bacterial superinfection within 48 hours of intubation was detected in 21% of patients. Seventy-two patients (44.4%) developed at least one VAP episode (VAP incidence rate = 45.2/1,000 ventilator days); 15 (20.8%) initial VAPs were caused by difficult-to-treat pathogens. The clinical criteria did not distinguish between patients with or without bacterial superinfection. BAL-based management was associated with significantly reduced antibiotic use compared with guideline recommendations. Conclusions: In patients with SARS-CoV-2 pneumonia requiring mechanical ventilation, bacterial superinfection at the time of intubation occurs in <25% of patients. Guideline-based empirical antibiotic management at the time of intubation results in antibiotic overuse. Bacterial VAP developed in 44% of patients and could not be accurately identified in the absence of microbiologic analysis of BAL fluid.