Phenotyping community-acquired pneumonia according to the presence of acute respiratory failure and severe sepsis

Comparison of clinical outcomes in hospitalized patients with COVID-19 or non-COVID-19 community-acquired pneumonia in a prospective observational cohort study

PURPOSE

Coronavirus disease 2019 (COVID-19) and non-COVID-19 community-acquired pneumonia (NC-CAP) often result in hospitalization with considerable risks of mortality, ICU treatment, and long-term morbidity. A comparative analysis of clinical outcomes in COVID-19 CAP (C-CAP) and NC-CAP may improve clinical management.

METHODS

Using prospectively collected CAPNETZ study data (January 2017 to June 2021, 35 study centers), we conducted a comprehensive analysis of clinical outcomes including in-hospital death, ICU treatment, length of hospital stay (LOHS), 180-day survival, and post-discharge re-hospitalization rate. Logistic regression models were used to examine group differences between C-CAP and NC-CAP patients and associations with patient demography, recruitment period, comorbidity, and treatment.

RESULTS

Among 1368 patients (C-CAP: n = 344; NC-CAP: n = 1024), C-CAP showed elevated adjusted probabilities for in-hospital death (aOR 4.48 [95% CI 2.38-8.53]) and ICU treatment (aOR 8.08 [95% CI 5.31-12.52]) compared to NC-CAP. C-CAP patients were at increased risk of LOHS over seven days (aOR 1.88 [95% CI 1.47-2.42]). Although ICU patients had similar in-hospital mortality risk, C-CAP was associated with length of ICU stay over seven days (aOR 3.59 [95% CI 1.65-8.38]). Recruitment period influenced outcomes in C-CAP but not in NC-CAP. During follow-up, C-CAP was linked to a reduced risk of re-hospitalization and mortality post-discharge (aOR 0.43 [95% CI 0.27-0.70]).

CONCLUSION

Distinct clinical trajectories of C-CAP and NC-CAP underscore the need for adapted management to avoid acute and long-term morbidity and mortality amid the evolving landscape of CAP pathogens.

Derivation and Validation of Generalized Sepsis-induced Acute Respiratory Failure Phenotypes Among Critically Ill Patients: A Retrospective Study

Background

Septic patients who develop acute respiratory failure (ARF) requiring mechanical ventilation represent a heterogenous subgroup of critically ill patients with widely variable clinical characteristics. Identifying distinct phenotypes of these patients may reveal insights about the broader heterogeneity in the clinical course of sepsis. We aimed to derive novel phenotypes of sepsis-induced ARF using observational clinical data and investigate their generalizability across multi-ICU specialties, considering multi-organ dynamics.

Methods

We performed a multi-center retrospective study of ICU patients with sepsis who required mechanical ventilation for ≥24 hours. Data from two different high-volume academic hospital systems were used as a derivation set with N=3,225 medical ICU (MICU) patients and a validation set with N=848 MICU patients. For the multi-ICU validation, we utilized retrospective data from two surgical ICUs at the same hospitals (N=1,577). Clinical data from 24 hours preceding intubation was used to derive distinct phenotypes using an explainable machine learning-based clustering model interpreted by clinical experts.

Results

Four distinct ARF phenotypes were identified: A (severe multi-organ dysfunction (MOD) with a high likelihood of kidney injury and heart failure), B (severe hypoxemic respiratory failure [median P/F=123]), C (mild hypoxia [median P/F=240]), and D (severe MOD with a high likelihood of hepatic injury, coagulopathy, and lactic acidosis). Patients in each phenotype showed differences in clinical course and mortality rates despite similarities in demographics and admission co-morbidities. The phenotypes were reproduced in external validation utilizing an external MICU from second hospital and SICUs from both centers. Kaplan-Meier analysis showed significant difference in 28-day mortality across the phenotypes (p<0.01) and consistent across both centers. The phenotypes demonstrated differences in treatment effects associated with high positive end-expiratory pressure (PEEP) strategy.

Conclusion

The phenotypes demonstrated unique patterns of organ injury and differences in clinical outcomes, which may help inform future research and clinical trial design for tailored management strategies.

Long-Term Outcomes in Severe Community-Acquired Pneumonia

Community-acquired pneumonia (CAP) is globally one of the major causes of hospitalization and mortality. Severe CAP (sCAP) presents great challenges and need a comprehensive understanding of its long-term outcomes. Cardiovascular events and neurological impairment, due to persistent inflammation and hypoxemia, contribute to long-term outcomes in CAP, including mortality. Very few data are available in the specific population of sCAP. Multiple studies have reported variable 1-year mortality rates for patients with CAP up to 40.7%, with a clear influence by age, comorbidities, and disease severity. In terms of treatment, the potential protective role of macrolides in reducing mortality emphasizes the importance of appropriate empiric antibiotic therapy. This narrative review explores the growing interest in the literature focusing on the long-term implications of sCAP. Improved understanding of long-term outcomes in sCAP can facilitate targeted interventions and enhance posthospitalization care protocols.

Treatment Failure and Clinical Stability in Severe Community-Acquired Pneumonia

Treatment failure and clinical stability are important outcomes in community-acquired pneumonia (CAP). It is essential to know the causes and risk factors for treatment failure and delay in reaching clinical stability in CAP. The study of both as well as the associated underlying mechanisms and host response are key to improving outcomes in pneumonia.

The prevalence of acute kidney injury in patients with community-acquired pneumonia who required mechanical ventilation

BACKGROUND

Community-acquired pneumonia (CAP) is a common reason for intensive care unit (ICU) admission and sepsis. Acute kidney injury (AKI) is a frequent complication of community-acquired pneumonia and is associated with increased short- and long-term morbidity and mortality and healthcare costs.

OBJECTIVE

Describe the prevalence of AKI in patients with CAP requiring mechanical ventilation and evaluate its association with inhospital mortality.

DESIGN

Retrospective cohort.

SETTING

Intensive care unit.

PATIENTS AND METHODS

We included patients with CAP on mechanical ventilation. Patients were categorized according to the development of AKI in the first 24 hours of ICU admission using the Kidney Disease Improving Global Outcomes (KDIGO) classification from no AKI, stage 1 AKI, stage 2 AKI, and stage 3 AKI.

MAIN OUTCOME MEASURES

The primary outcome was hospital mortality. Secondary outcomes were ICU mortality, hospital and ICU length of stay, ventilation duration, tracheostomy, and renal replacement therapy requirement.

RESULTS

Of 1536 patients included in the study, 829 patients (54%) had no AKI while 707 (46%) developed AKI. In-hospital mortality was 288/829 (34.8%) for patients with no AKI, 43/111 (38.7%) for stage 1 AKI, 86/216 (40%) for stage 2 AKI, and 196/380 (51.7%) for stage 3 AKI (P<.0001). Multivariate analysis revealed that stages 1, 2, or 3 AKI compared to no AKI were not independently associated with in-hospital mortality. Older age, vasopressor use; decreased Glasgow coma scale, PaO2/Fio2 ratio and platelet count, increased bilirubin, lactic acid and INR were associated with increased mortality while female sex was associated with reduced mortality.

CONCLUSION

Among mechanically ventilated patients with CAP, AKI was common and was associated with higher crude mortality. The higher mortality could not be attributed alone to AKI, but rather appeared to be related to multi-organ dysfunction.

LIMITATIONS

Single-center retrospective study with no data on baseline serum creatinine and the use of estimated baseline creatinine distributions based on the MDRD (Modification of Diet in Renal Disease)equation which may lead to an overestimation of AKI. Second, we did not have data on the microbiology of pneumonia, appropriateness of antibiotic therapy or the administration of other medications that have been demonstrated to be associated with AKI.

N-acetylcysteine efficacy in patients hospitalized with COVID-19 pneumonia: a systematic review and meta-analysis

BACKGROUND

N-acetylcysteine (NAC) is a mucolytic agents with anti-inflammatory properties that has been suggested as an adjunctive therapy in patients with COVID-19 pneumonia.

OBJECTIVES

We conducted a systematic review and meta-analysis to evaluate available evidence on the possible beneficial effects of NAC on SARS-CoV-2 infection.

METHODS

In September 2022, we conducted a comprehensive search on Pubmed/Medline and Embase on randomized controlled trials (RCTs) and observational studies on NAC in patients with COVID-19 pneumonia. Study selection, data extraction and risk of bias assessment was performed by two independent authors. RCTs and observational studies were analyzed separately.

RESULTS

We included 3 RCTs and 5 non-randomized studies on the efficacy of NAC in patients with COVID-19, enrolling 315 and 20826 patients respectively. Regarding in-hospital mortality, the summary effect of all RCTs was OR: 0.85 (95% CI: 0.43 to 1.67, I²=0%) and for non-randomized studies OR: 1.02 (95% CI: 0.47 to 2.23, I²=91%). Need for ICU admission was only reported by 1 RCT (OR: 0.86, 95% CI:0.44-1.69, p=0.66), while all included RCTs reported need for invasive ventilation (OR:0.91, 95% CI:0.54 to 1.53, I²=0). Risk of bias was low for all included RCTs, but certainty of evidence was very low for all outcomes due to serious imprecision and indirectness.

CONCLUSION

The certainty of evidence in the included studies was very low, thus recommendations for clinical practice cannot be yet made. For all hard clinical outcomes point estimates in RCTs are close to the line of no effect, while observational studies have a high degree of heterogeneity with some of them suggesting favorable results in patients receiving NAC. More research is warranted to insure that NAC is both effective and safe in patients with COVID-19 pneumonia.

Myristoyl lysophosphatidylcholine is a biomarker and potential therapeutic target for community-acquired pneumonia

There is no gold standard for evaluating the severity of community-acquired pneumonia (CAP), and it is still based on a score. This study aimed to use the metabolomics method to find promised biomarkers in assessing disease severity and potential therapeutic targets for CAP. The result found that the metabolites in the plasma samples of CAP patients had significantly different between the acute phase and the remission phase, especially lysophosphatidylcholine (LPCs) in glycerophospholipids, whose levels are negatively linked to the severity of the disease. Subsequently, the two key metabolites of myristoyl lysophosphatidylcholine (LPC 14:0) and LPC 16:1 were screened. We analyzed the predictive performance of the two metabolites using Spearman-related analysis and ROC curves, and LPC14:0 showed more satisfactory diagnostic performance than LPC16:1. Then we explored the protective role and mechanism of LPC 14:0 in animal and cell models. The results showed that LPC 14:0 could inhibit the LPS-induced secretion of IL-1β, IL-6, and TNF-α, lower the ROS and MDA levels, and decreased the depletion of SOD and GSH, thereby reducing lung tissue and cell damage, such as down-regulating the protein level in BALF, lung W/D ratio, MPO activity, and apoptosis. We found that LPC 14:0 inhibited LPS-induced inflammatory response and oxidative stress, and the above protection was achieved by inhibiting LPS-induced activation of the NLRP3 inflammasome. LPC 14:0 may serve as a novel biomarker for predicting the severity of CAP. In addition, our exploration of the role of LPC 14:0 in animal and cellular models has reinforced its promise as a therapeutic target to improve the clinical efficacy for CAP.

LOw-dose CT Or Lung UltraSonography versus standard of care based-strategies for the diagnosis of pneumonia in the elderly: protocol for a multicentre randomised controlled trial (OCTOPLUS)

INTRODUCTION

Pneumonia is a leading cause of mortality and a common indication for antibiotic in elderly patients. However, its diagnosis is often inaccurate. We aim to compare the diagnostic accuracy, the clinical and cost outcomes and the use of antibiotics associated with three imaging strategies in patients >65 years old with suspected pneumonia in the emergency room (ER): chest X-ray (CXR, standard of care), low-dose CT scan (LDCT) or lung ultrasonography (LUS).

METHODS AND ANALYSIS

This is a multicentre randomised superiority clinical trial with three parallel arms. Patients will be allocated in the ER to a diagnostic strategy based on either CXR, LDCT or LUS. All three imaging modalities will be performed but the results of two of them will be masked during 5 days to the patients, the physicians in charge of the patients and the investigators according to random allocation. The primary objective is to compare the accuracy of LDCT versus CXR-based strategies. As secondary objectives, antibiotics prescription, clinical and cost outcomes will be compared, and the same analyses repeated to compare the LUS and CXR strategies. The reference diagnosis will be established a posteriori by a panel of experts. Based on a previous study, we expect an improvement of 16% of the accuracy of pneumonia diagnosis using LDCT instead of CXR. Under this assumption, and accounting for 10% of drop-out, the enrolment of 495 patients is needed to prove the superiority of LDCT over CRX (alpha error=0.05, beta error=0.10).

ETHICS AND DISSEMINATION

Ethical approval: CER Geneva 2019-01288.

TRIAL REGISTRATION NUMBER

NCT04978116.

Global Perspective of Legionella Infection in Community-Acquired Pneumonia: A Systematic Review and Meta-Analysis of Observational Studies

Legionnaires’ disease (LD) (Legionella) is a common cause of community-acquired pneumonia (CAP) in those requiring hospitalization. Geographical variation in the importance of Legionella species as an aetiologic agent of CAP is poorly understood. We performed a systematic review and meta-analysis of population-based observational studies that reported the proportion of Legionella infection in patients with CAP (1 January 1990 to 31 May 2020). Using five electronic databases, articles were identified, appraised and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The quality of the included studies was assessed using the Newcastle–Ottawa Scale. Univariate and multivariate meta-regression analyses were conducted using study design, WHO region, study quality and healthcare setting as the explanatory variables. We reviewed 2778 studies, of which 219 were included in the meta-analysis. The mean incidence of CAP was 46.7/100,000 population (95% CI: 46.6–46.8). The mean proportion of Legionella as the causative agent for CAP was 4.6% (95% CI: 4.4 to 4.7). Consequently, the mean Legionella incidence rate was 2.8/100,000 population (95% CI: 2.7–2.9). There was significant heterogeneity across all studies I² = 99.27% (p < 0.0001). After outliers were removed, there was a decrease in the heterogeneity (I² = 43.53%). Legionella contribution to CAP has a global distribution. Although the rates appear highest in high income countries in temperate regions, there are insufficient studies from low- and middle-income countries to draw conclusions about the rates in these regions. Nevertheless, this study provides an estimate of the mean incidence of Legionella infection in CAP, which could be used to estimate the regional and global burden of LD to support efforts to reduce the impact of this infection as well as to fill important knowledge gaps.

Understanding the Host in the Management of Pneumonia. An Official American Thoracic Society Workshop Report

Pneumonia causes a significant burden of disease worldwide. Although all populations are at risk of pneumonia, those at extremes of age and those with immunosuppressive disorders, underlying respiratory disease, and critical illness are particularly vulnerable. Although clinical practice guidelines addressing the management and treatment of pneumonia exist, few of the supporting studies focus on the crucial contributions of the host in pneumonia pathogenesis and recovery. Such essential considerations include the host risk factors that lead to susceptibility to lung infections; biomarkers reflecting the host response and the means to pursue host-directed pneumonia therapy; systemic effects of pneumonia on the host; and long-term health outcomes after pneumonia. To address these gaps, the Pneumonia Working Group of the Assembly on Pulmonary Infection and Tuberculosis led a workshop held at the American Thoracic Society meeting in May 2018 with overarching objectives to foster attention, stimulate research, and promote funding for short-term and long-term investigations into the host contributions to pneumonia. The workshop involved participants from various disciplines with expertise in lung infection, pneumonia, sepsis, immunocompromised patients, translational biology, data science, genomics, systems biology, and clinical trials. This workshop report summarizes the presentations and discussions and important recommendations for future clinical pneumonia studies. These recommendations include establishing consensus disease and outcome definitions, improved phenotyping, development of clinical study networks, standardized data and biospecimen collection and protocols, and development of innovative trial designs.

Community-acquired pneumonia

Community-acquired pneumonia is not usually considered a high-priority problem by the public, although it is responsible for substantial mortality, with a third of patients dying within 1 year after being discharged from hospital for pneumoniae. Although up to 18% of patients with community-acquired pneumonia who were hospitalised (admitted to hospital and treated there) have at least one risk factor for immunosuppression worldwide, strong evidence on community-acquired pneumonia management in this population is scarce. Several features of clinical management for community-acquired pneumonia should be addressed to reduce mortality, morbidity, and complications related to community-acquired pneumonia in patients who are immunocompetent and patients who are immunocompromised. These features include rapid diagnosis, microbiological investigation, prevention and management of complications (eg, respiratory failure, sepsis, and multiorgan failure), empirical antibiotic therapy in accordance with patient's risk factors and local microbiological epidemiology, individualised antibiotic therapy according to microbiological data, appropriate outcomes for therapeutic switch from parenteral to oral antibiotics, discharge planning, and long-term follow-up. This Seminar offers an updated view on community-acquired pneumonia in adults, with suggestions for clinical and translational research.

[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.

Impact of acute kidney injury on in-hospital outcomes in Chinese patients with community acquired pneumonia

BACKGROUND

Acute kidney injury (AKI) is a frequent complication of community acquired pneumonia (CAP). However, the impact of AKI on in-hospital outcomes of patients with CAP in the Chinese population remains unclear.

METHODS

Patients diagnosed with CAP were evaluated in this retrospective observational study. Multiple Cox regression models were employed to identify the association between AKI and in-hospital mortality and 30-day mortality, respectively.

RESULTS

A total of 4213 patients were recruited; 950 (22.5%) patients were diagnosed with AKI. Independent risk factors for AKI were age, male gender, hypertension, cardiac dysfunction, diabetes, chronic kidney disease, acute respiratory failure, use of diuretics, use of vasoactive drugs, and CURB-65. Cox proportional hazards regression revealed AKI, use of angiotensin receptor blocker, hypertension, CURB-65, acute respiratory failure, and use of vasoactive drugs to be independent risk factors for both in-hospital and 30-day mortality. Compared to patients without AKI, those suffering AKI were found to have 1.31-fold (HR 1.31, 95% CI, 1.04-1.66; P = 0.023) and 1.29-fold (HR 1.29, 95% CI, 1.02-1.62; P = 0.033) increased in-hospital and 30-day mortality risks, respectively. In addition, patients with AKI were likely to require admission to intensive care unit (ICU) (42.9% versus 11.4%; P < 0.001), mechanical ventilation (33.8% versus 9.3%; P < 0.001), invasive mechanical ventilation (25.9% versus 5.8%; P < 0.001), non-invasive mechanical ventilation (25.4% versus 7.1%; P < 0.001), and experienced a longer duration of hospital stay (14 days versus 10 days; P < 0.001) than those without AKI. However, no significant difference in ICU stay (11 days versus 10 days; P = 0.099) and duration of mechanical ventilation (8 days versus 8 days; P = 0.369) between AKI and non-AKI groups was found.

CONCLUSION

AKI was common in Chinese patients with CAP. Patients with CAP who developed AKI had worse in-hospital outcomes.

Admission lysophosphatidylethanolamine acyltransferase level predicts the severity and prognosis of community-acquired pneumonia

PURPOSE

Early diagnosis and prognosis of patients with community-acquired pneumonia (CAP) are still difficult clinical challenges. This study aimed to investigate the role of lysophosphatidylethanolamine acyltransferase (LPEAT) in CAP and to evaluate the effectiveness of this enzyme as an indicator of disease severity and risk of death in CAP.

METHODS

This retrospective, multi-center study was conducted in 2017. A total of 267 patients with CAP were included. Of these 267 patients, 175 patients had non-severe CAP (non-SCAP) and 92 patients had severe CAP (SCAP). In addition, we recruited 15 healthy volunteers and 42 hospitalized disease controls in our study. The demographic and clinical characteristics were recorded for all participants. Admission levels of LPEAT were determined by quantitative enzyme-linked immunosorbent assay.

RESULTS

Admission levels of LPEAT in patients with SCAP were significantly higher, particularly in non-survivors and were not affected by the causative etiology. Furthermore, when the patients were stratified according to PSI and CURB-65 scores, the patients with high severity scores had higher LPEAT levels upon admission than patients with low severity scores. LPEAT also performed well in predicting SCAP in patients with CAP. Moreover, LPEAT could predict the 30-day mortality rate of patients with CAP, and combining LPEAT with the clinical severity score further improved the accuracy of mortality prediction.

CONCLUSION

Elevated LPEAT levels can reliably predict the severity of illness in patients with CAP at the time of admission. Adding LPEAT to clinical scoring methods could improve prognostic accuracy. Trial registration ClinicalTrials.gov, NCT03093220. Registered on March 28th, 2017.

Pneumonic versus Nonpneumonic Exacerbations of Chronic Obstructive Pulmonary Disease

Patients with chronic obstructive pulmonary disease (COPD) often suffer acute exacerbations (AECOPD) and community-acquired pneumonia (CAP), named nonpneumonic and pneumonic exacerbations of COPD, respectively. Abnormal host defense mechanisms may play a role in the specificity of the systemic inflammatory response. Given the association of this aspect to some biomarkers at admission (e.g., C-reactive protein), it can be used to help to discriminate AECOPD and CAP, especially in cases with doubtful infiltrates and advanced lung impairment. Fever, sputum purulence, chills, and pleuritic pain are typical clinical features of CAP in a patient with COPD, whereas isolated dyspnea at admission has been reported to predict AECOPD. Although CAP may have a worse outcome in terms of mortality (in hospital and short term), length of hospitalization, and early readmission rates, this has only been confirmed in a few prospective studies. There is a lack of methodologically sound research confirming the impact of severe AECOPD and COPD + CAP. Here, we review studies reporting head-to-head comparisons between AECOPD and CAP + COPD in hospitalized patients. We focus on the epidemiology, risk factors, systemic inflammatory response, clinical and microbiological characteristics, outcomes, and treatment approaches. Finally, we briefly discuss some proposals on how we should orient research in the future.

Computed tomography scan contribution to the diagnosis of community-acquired pneumonia

Purpose of review

Pneumonia is a frequent disease mainly affecting older and multimorbid patients. Symptoms and signs lack sensitivity and specificity, and chest X-ray has poor accuracy. Hence, an initial diagnosis of pneumonia has limited predictive value for the presence of pneumonia. Overdiagnosis of pneumonia leads to inappropriate antibiotic use and may delay the appropriate management of mimicking diseases. Alternative imaging strategies including computed tomography (CT)-scan or lung ultrasonography may improve the diagnosis of pneumonia. We review the recent evidence and perspectives regarding their contribution to the diagnosis and management of patients with suspected pneumonia.

Recent findings

Two studies assessed the diagnostic accuracy of CT-scan in emergency department or hospitalized patients suspected of pneumonia. CT-scan led to a net reclassification improvement of 8 and 18% of patients, and was particularly helpful to rule out the diagnosis, allowing a lowering of the number of inappropriate antibiotic prescriptions.

Summary

CT-scan reduces overdiagnosis of pneumonia and allows a better identification of alternative diagnoses. The impact on clinical outcomes of a strategy incorporating CT-scan for patients suspected of pneumonia should be evaluated, along with its cost-effectiveness.

Is chronic obstructive pulmonary disease a risk factor for death in patients with community acquired pneumonia?

BACKGROUND

It is still a matter of debate whether the outcome of community acquired pneumonia is more severe in patients with chronic obstructive pulmonary disease. We aimed to determine whether chronic obstructive pulmonary disease was associated with increased mortality and to identify risk-factors for mortality in patients with community acquired pneumonia and chronic obstructive pulmonary disease.

METHODS

Retrospective cohort study comparing patients with community acquired pneumonia and chronic obstructive pulmonary disease to patients without chronic obstructive pulmonary disease. We included 1309 patients with community acquired pneumonia admitted from 2011 until 2012 (243 patients with chronic obstructive pulmonary disease and 1066 without chronic obstructive pulmonary disease).

RESULTS

At admission patients with community acquired pneumonia and chronic obstructive pulmonary disease presented with more severe pneumonia as measured by CURB-65 score compared to patients without chronic obstructive pulmonary disease. Mortality on day 30 was generally high, and higher among patients with community acquired pneumonia and chronic obstructive pulmonary disease compared to those without chronic obstructive pulmonary disease (16.0% versus 11.3%, p = .04). In an adjusted analysis, however, chronic obstructive pulmonary disease was not independently associated with 30-d mortality (odds ratio 0.94, confidence interval 95% 0.59-1.50). Factors related to mortality in patients with community acquired pneumonia and chronic obstructive pulmonary disease were age, premorbid condition, severity of pneumonia as determined by CURB-65 score, and pleural effusion and multi-lobular infiltrate on chest X-ray.

CONCLUSIONS

Chronic obstructive pulmonary disease was not independently associated with 30-d mortality in patients with community acquired pneumonia.

How can we improve clinical research in pneumonia?

PURPOSE OF REVIEW

The primary challenges in the field of clinical research include a lack of support within existing infrastructure, insufficient number of clinical research training programs and a paucity of qualified mentors. Most medical centers offer infrastructure support for investigators working with industry sponsors or government-funded clinical trials, yet there are a significant amount of clinical studies performed in the field of pneumonia which are observational studies. For this type of research, which is frequently unfunded, support is usually lacking.

RECENT FINDINGS

In an attempt to optimize clinical research in pneumonia, at the University of Louisville, we developed a clinical research coordinating center (CRCC). The center manages clinical studies in the field of respiratory infections, with the primary focus being pneumonia. Other activities of the CRCC include the organization of an annual clinical research training course for physicians and other healthcare workers, and the facilitation of international research mentoring by a process of connecting new pneumonia investigators with established clinical investigators.

SUMMARY

To improve clinical research in pneumonia, institutions need to have the appropriate infrastructure in place to support investigators in all aspects of the clinical research process.

Management of Acute Respiratory Failure Due to Community-Acquired Pneumonia: A Systematic Review

Community-acquired pneumonia (CAP) is a leading cause of mortality worldwide. CAP mortality is driven by the development of sepsis and acute respiratory failure (ARF). We performed a systematic review of the available English literature published in the period 1 January 1997 to 31 August 2017 and focused on ARF in CAP. The database searches identified 189 articles—of these, only 29 were retained for data extraction. Of these 29 articles, 12 addressed ARF in CAP without discussing its ventilatory management, while 17 evaluated the ventilatory management of ARF in CAP. In the studies assessing the ventilatory management, the specific treatments addressed were: high-flow nasal cannula (HFNC) (n = 1), continuous positive airway pressure (n = 2), non-invasive ventilation (n = 9), and invasive mechanical ventilation (n = 5). When analyzed, non-invasive ventilation (NIV) success rates ranged from 20% to 76% and they strongly predicted survival, while NIV failure led to an increased risk of adverse outcome. In conclusion, ARF in CAP patients may require both ventilatory and non-ventilatory management. Further research is needed to better evaluate the use of NIV and HFNC in those patients. Alongside the prompt administration of antimicrobials, the potential use of steroids and the implementation of severity scores should also be considered.

Non-invasive positive pressure ventilation in pneumonia outside Intensive Care Unit: An Italian multicenter observational study

BACKGROUND AND OBJECTIVE

Non-Invasive Ventilation (NIV) represents a standard of care to treat some acute respiratory failure (ARF). Data on its use in pneumonia are lacking, especially in a setting outside the Intensive Care Unit (ICU). The aims of this study were to evaluate the use of NIV in ARF due to pneumonia outside the ICU, and to identify risk factors for in-hospital mortality.

METHODS

Prospective, observational study performed in 19 centers in Italy. Patients with ARF due to pneumonia treated outside the ICU with either continuous positive airway pressure (CPAP) or noninvasive positive pressure ventilation (NPPV) were enrolled over a period of at least 3 consecutive months in 2013. Independent factors related to in-hospital mortality were evaluated.

RESULTS

Among the 347 patients enrolled, CPAP was applied as first treatment in 176 (50.7%) patients,NPPV in 171 (49.3%). The NPPV compared with CPAP group showed a significant higher PaCO₂ (55 [47-78] vs 37 [32-43] mmHg, p < 0.001), a lower arterial pH (7.30 [7.21-7.37] vs 7.43 [7.35-7.47], p < 0.001), higher HCO3- (28 [24-33] vs 24 [21-27] mmol/L, p < 0.001). De-novo ARF was more prevalent in CPAP group than in NPPV group (86/176 vs 31/171 patients,p < 0.001). In-hospital mortality was 23% (83/347). Do Not Intubate (DNI) order and Charlson Comorbidity Index (CCI) ≥3 were independent risk factors for in-hospital mortality.

CONCLUSIONS

Outside ICU setting, CPAP was used mainly for hypoxemic non-hypercapnic ARF, NPPV for hypercapnic ARF. In-hospital mortality was mainly associated to patients' basal status (DNI status, CCI) rather than the baseline degree of ARF.

Metabolic profiles in community-acquired pneumonia: developing assessment tools for disease severity

Background

This study aimed to determine whether community-acquired pneumonia (CAP) had a metabolic profile and whether this profile can be used for disease severity assessment.

Methods

A total of 175 individuals including 119 CAP patients and 56 controls were enrolled and divided into two cohorts. Serum samples from a discovery cohort (n = 102, including 38 non-severe CAP, 30 severe CAP, and 34 age and sex-matched controls) were determined by untargeted ultra-high-performance liquid chromatography with tandem mass spectrometry (LC-MS/MS)-based metabolomics. Selected differential metabolites between CAP patients versus controls, and between the severe CAP group versus non-severe CAP group, were confirmed by targeted mass spectrometry assays in a validation cohort (n = 73, including 32 non-severe CAP, 19 severe CAP and 22 controls). Pearson’s correlation analysis was performed to assess relationships between the identified metabolites and clinical severity of CAP. The area under the curve (AUC), sensitivity and specificity of the metabolites for predicting the severity of CAP were also investigated.

Results

The metabolic signature was markedly different between CAP patients and controls. Fifteen metabolites were found to be significantly dysregulated in CAP patients, which were mainly mapped to the metabolic pathways of sphingolipid, arginine, pyruvate and inositol phosphate. The alternation trends of five metabolites among the three groups including sphinganine, p-Cresol sulfate, dehydroepiandrosterone sulfate (DHEA-S), lactate and l-arginine in the validation cohort were consistent with those in the discovery cohort. Significantly lower concentrations of sphinganine, p-Cresol sulfate and DHEA-S were observed in CAP patients than in controls (p < 0.05). Serum lactate and sphinganine levels were positively correlated with confusion, urea level, respiratory rate, blood pressure, and age > 65 years (CURB-65), pneumonia severity index (PSI) and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, while DHEA-S inversely correlated with the three scoring systems. Combining lactate, sphinganine and DHEA-S as a metabolite panel for discriminating severe CAP from non-severe CAP exhibited a better AUC of 0.911 (95% confidence interval 0.825–0.998) than CURB-65, PSI and APACHE II scores.

Conclusions

This study demonstrates that serum metabolomics approaches based on the LC-MS/MS platform can be applied as a tool to reveal metabolic changes during CAP and establish a metabolite signature related to disease severity.

Trial registration

ClinicalTrials.gov, NCT03093220. Registered retrospectively on 28 March 2017.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2049-2) contains supplementary material, which is available to authorized users.

Pneumonia as a cardiovascular disease

Community-acquired pneumonia (CAP) is an important cause of death around the globe. Up to 30% of patients admitted to hospital for CAP develop cardiovascular complications (i.e. new/worsening heart failure, new/worsening arrhythmias, myocardial infarctions and/or strokes), acutely and up to 10 years thereafter. Cardiac complications result from complex interactions between preexisting conditions, relative ischaemia, upregulation of the sympathetic system, systemic inflammation and direct pathogen-mediated damage to the cardiovascular system. The exact mechanisms underlying the direct host-pathogen interactions are of great interest to identify potential therapeutic and preventative targets for CAP. In this review, we summarize the epidemiological data, risk factors and the pathogen-driven cardiovascular damage affecting patients with CAP.

Lymphopenic Community Acquired Pneumonia (L-CAP), an Immunological Phenotype Associated with Higher Risk of Mortality

The role of neutrophil and lymphocyte counts in blood as prognosis predictors in Community Acquired Pneumonia (CAP) has not been adequately studied. This was a derivation-validation retrospective study in hospitalized patients with CAP and no prior immunosuppression. We evaluated by multivariate analysis the association between neutrophil and lymphocyte counts and mortality risk at 30-days post hospital admission in these patients. The derivation cohort (n=1550 patients) was recruited in a multi-site study. The validation cohort (n=2846 patients) was recruited in a single-site study. In the derivation cohort, a sub-group of lymphopenic patients, those with <724lymphocytes/mm³, showed a 1.93-fold increment in the risk of mortality, independently of the CURB-65 score, critical illness, and receiving an appropriate antibiotic treatment. In the validation cohort, patients with <724lymphocytes/mm³ showed a 1.86-fold increment in the risk of mortality. The addition of 1 point to the CURB-65 score in those patients with <724lymphocytes/mm³ improved the performance of this score to identify non-survivors in both cohorts. In conclusion, lymphopenic CAP constitutes a particular immunological phenotype of the disease which is associated with an increased risk of mortality. Assessing lymphocyte counts could contribute to personalized clinical management in CAP.

Admission lactate predicts poor prognosis independently of the CRB/CURB-65 scores in community-acquired pneumonia

OBJECTIVES

Community-acquired pneumonia (CAP) is associated with a high risk of respiratory failure or septic organ dysfunction. Lactate is an established early marker of prognosis and sepsis severity, but few data exist in patients with CAP.

METHODS

We performed a retrospective cohort study of consecutive adult CAP patients without treatment restrictions or direct intensive care unit admission. Lactate was measured as a point-of-care test within the capillary admission blood gas analysis, and its prognostic value was compared to the CRB/CURB-65 criteria by multivariate and receiver operating characteristic (ROC) curve analysis. The primary endpoint was the combination of need for mechanical ventilation, vasopressors, intensive care unit admission or hospital mortality.

RESULTS

Of 303 included patients, 75 (25%) met the primary endpoint. After ROC analysis, lactate predicted the primary endpoint (area under the curve 0.67) with an optimal cutoff of >1.8 mmol/L. Of the 76 patients with lactate above this threshold, 35 (46%) met the primary endpoint. After multivariate analysis, the predictive value of lactate was independent of the CRB/CURB-65 scores. The addition of lactate >1.8 mmol/L to the CRB/CURB-65 scores resulted in significantly improved area under the curves (0.69 to 0.74, p 0.005 and 0.71 to 0.75, p 0.008 respectively). Fourteen (42%) of 33 and 11 (39%) of 28 patients meeting the endpoint despite presenting with 0 or 1 CRB/CURB-65 criteria had lactate >1.8 mmol/L.

CONCLUSIONS

Admission lactate levels significantly improved the prognostic value of the CRB/CURB-65 scores in CAP patients. Lactate may therefore be considered a rapid, cheap and broadly available additional criterion for the assessment of risk in patients with CAP.

Efficacy and Safety of Adjunctive Corticosteroids Therapy for Severe Community-Acquired Pneumonia in Adults: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Adjunctive corticosteroids therapy is an attractive option for community-acquired pneumonia (CAP) treatment. However, the effectiveness of adjunctive corticosteroids on mortality of CAP remains inconsistent, especially in severe CAP. We performed a meta-analysis to evaluate the efficacy and safety of adjunctive corticosteroids in severe CAP patients.

METHODS

Three databases of PubMed, EMBASE and Cochrane Library were searched for related studies published in English up to December, 2015. Randomized controlled trials (RCTs) of corticosteroids in hospitalized adults with severe CAP were included. Meta-analysis was performed by a random-effect model with STATA 11.0 software. We estimated the summary risk ratios (RRs) or effect size (ES) with its corresponding 95% confidence interval (95%CI) to assess the outcomes.

RESULTS

We included 8 RCTs enrolling 528 severe CAP patients. Adjunctive corticosteroids significantly reduced all-cause mortality (RR = 0.46, 95%CI: 0.28 to 0.77, p = 0.003), risk of adult respiratory distress syndrome (ARDS) (RR = 0.23, 95%CI: 0.07 to 0.80, p = 0.02) and need for mechanical ventilation (RR = 0.50, 95%CI: 0.27 to 0.92, p = 0.026). Adjunctive corticosteroids did not increase frequency of hyperglycemia requiring treatment (RR = 1.03, 95%CI: 0.61 to 1.72, p = 0.91) or gastrointestinal hemorrhage (RR = 0.66, 95%CI: 0.19 to 2.31, p = 0.52). In subgroup analysis by duration of corticosteroids, we found that prolonged corticosteroids therapy significantly reduced all-cause mortality (RR = 0.41, 95%CI: 0.20 to 0.83, p = 0.01) and length of hospital stay (-4.76 days, 95% CI:-8.13 to -1.40, p = 0.006).

CONCLUSIONS

Results from this meta-analysis suggested that adjunctive corticosteroids therapy was safe and beneficial for severe CAP. In addition, prolonged corticosteroids therapy was more effective. These results should be confirmed by adequately powered studies in the future.

Severe community-acquired pneumonia: timely management measures in the first 24 hours

Mortality rates for severe community-acquired pneumonia (CAP) range from 17 to 48 % in published studies.In this review, we searched PubMed for relevant papers published between 1981 and June 2016 and relevant files. We explored how early and aggressive management measures, implemented within 24 hours of recognition of severe CAP and carried out both in the emergency department and in the ICU, decrease mortality in severe CAP.These measures begin with the use of severity assessment tools and the application of care bundles via clinical decision support tools. The bundles include early guideline-concordant antibiotics including macrolides, early haemodynamic support (lactate measurement, intravenous fluids, and vasopressors), and early respiratory support (high-flow nasal cannulae, lung-protective ventilation, prone positioning, and neuromuscular blockade for acute respiratory distress syndrome).While the proposed interventions appear straightforward, multiple barriers to their implementation exist. To successfully decrease mortality for severe CAP, early and close collaboration between emergency medicine and respiratory and critical care medicine teams is required. We propose a workflow incorporating these interventions.

Pneumonia presenting with organ dysfunctions: Causative microorganisms, host factors and outcome

Community-acquired pneumonia (CAP) is a serious infection that may occasionally rapidly evolve provoking organ dysfunctions. We aimed to characterize CAP presenting with organ dysfunctions at the emergency room, with regard to host factors and causative microorganisms, and its impact on 30-day mortality. 460 of 4070 (11.3%) CAP patients had ≥2 dysfunctions at diagnosis, with a 30-day mortality of 12.4% vs. 3.4% in those with one or no dysfunctions. Among them, the most frequent causative microorganisms were Streptococcus pneumoniae, gram-negatives and polymicrobial etiology. Independent host risk factors for presenting with ≥2 dysfunctions were: liver (OR 2.97) and renal diseases (OR 3.91), neurological disorders (OR 1.86), and COPD (OR 1.30). Methicillin-resistant Staphylococcus aureus (OR 6.41) and bacteraemic episodes (OR 1.68) had the higher independent risk among microorganisms. The number of organ dysfunctions vs. none increased at 30-day mortality: three organs (OR 11.73), two organs (OR 4.29), and one organ (OR 2.42) whereas Enterobacteria (OR 3.73) were also independently related to mortality. The number of organ dysfunctions was the strongest 30-day mortality risk factor while Enterobacteriaceae was also associated with poorer outcome. The assessment of organ dysfunctions in CAP should be implemented for management, allocation and treatment decisions on initial evaluation.

Advances in the prevention, management, and treatment of community-acquired pneumonia

Community-acquired pneumonia (CAP) is the infectious disease with the highest number of deaths worldwide. Nevertheless, its importance is often underestimated. Large cohorts of patients with CAP have been established worldwide and improved our knowledge about CAP by far. Therefore, current guidelines are much more evidence-based than ever before. This article discusses recent major studies and concepts on CAP such as the role of biomarkers, appropriate risk stratification to identify patients in need of hospitalisation or intensive care, appropriate empiric antibiotic therapy (including the impact of macrolide combination therapy and antibiotic stewardship), and CAP prevention with novel influenza and pneumococcal vaccines.

Acute myocardial infarction versus other cardiovascular events in community-acquired pneumonia

The aim of the present study was to define the prevalence, characteristics, risk factors and impact on clinical outcomes of acute myocardial infarction (AMI) versus other cardiovascular events (CVEs) in patients with community-acquired pneumonia (CAP).

This was an international, multicentre, observational, prospective study of CAP patients hospitalised in eight hospitals in Italy and Switzerland. Three groups were identified: those without CVEs, those with AMI and those with other CVEs.

Among 905 patients, 21 (2.3%) patients experienced at least one AMI, while 107 (11.7%) patients experienced at least one other CVE. Patients with CAP and either AMI or other CVEs showed a higher severity of the disease than patients with CAP alone. Female sex, liver disease and the presence of severe sepsis were independent predictors for the occurrence of AMI, while female sex, age >65 years, neurological disease and the presence of pleural effusion predicted other CVEs. In-hospital mortality was significantly higher among those who experienced AMI in comparison to those experiencing other CVEs (43% versus 21%, p=0.039). The presence of AMI showed an adjusted odds ratio for in-hospital mortality of 3.57 (p=0.012) and for other CVEs of 2.63 (p=0.002).

These findings on AMI versus other CVEs as complications of CAP may be important when planning interventional studies on cardioprotective medications.

Acute myocardial infarction is associated with specific risk factors and accounts for worse outcomes in CAP patientshttp://ow.ly/QhT2t

Assessment of oxygenation and comorbidities improves outcome prediction in patients with community-acquired pneumonia with a low CRB-65 score

BACKGROUND

Addition of assessment of comorbid diseases ('D') and oxygen saturation ('S') to the CRB-65 score has been recommended to improve its accuracy for risk stratification in community-acquired pneumonia (CAP). The aim of this study was to validate the resulting DS-CRB-65 score in a large cohort of patients with CAP.

METHODS

A total of 4432 patients prospectively enrolled in the CAPNETZ cohort were included in this study. Predefined end points were 28-day mortality, requirement for mechanical ventilation or vasopressors (MV/VS) and requirement for MV/VS or intensive care unit admission (MV/VS/ICU). Receiver operating characteristic curve analysis was used to determine the accuracy of the CRB-65 score and the addition of D (extra-pulmonary comorbidities) and S (oxygen saturation <90% or partial pressure of oxygen <8 kPa). Binary logistic regression and the method of Hanley and McNeil were used to compare the criteria.

RESULTS

The mortality rate was 4.0%, and 4.2% of patients required MV/VS and 6.6% required MV/VS/ICU. After multivariate analysis, D and S independently were added to the CRB-65 criteria for mortality prediction, but only S improved prediction of MV/VS and MV/VS/ICU (P < 0.001 for all). The area under the curve of the CRB-65 score was significantly improved by adding D and S for all end points (P < 0.02). Amongst patients who died or required MV/VS despite a CRB-65 score of 0, 64-80% would have been identified by the DS-CRB-65 score.

CONCLUSIONS

The addition of assessment of oxygenation and comorbidities significantly improved the prognostic accuracy of the CRB-65 score. Consequently, the DS-CRB-65 score may have a useful role in risk stratification algorithms for CAP.

Opening of a respiratory intermediate care unit in a general hospital: impact on mortality and other outcomes

BACKGROUND

Respiratory intermediate care units (RICUs) are specialized areas aimed at optimizing the cost-benefit ratio of care. No data exist about the impact of opening a RICU on hospital outcomes.

OBJECTIVES

We wondered if opening a RICU may improve the outcomes of patients with acute respiratory failure (ARF), acute exacerbation of chronic obstructive pulmonary disease (AECOPD), or community-acquired pneumonia (CAP).

METHODS

We analyzed the discharge abstracts of 2,372 admissions to the RICU and internal medicine units (IMUs) for ARF, AECOPD, and CAP. The IMUs at the Hospital of Trieste comprise emergency and internal wards. In order to investigate the determinants of outcomes, a matched case-control study was performed using clinical records.

RESULTS

The in-hospital mortality rate was lower in the RICU vs. IMUs (5.4 vs. 19.1%, p = 0.0001). Statistical differences did not change when comparing the RICU with the emergency and internal wards. After adjusting for potential confounders, the risk of death for patients with CAP, AECOPD, or ARF was significantly higher in the IMUs than in the RICU (OR 6.90, 3.19, and 6.7, respectively, p < 0.04). Both the frequency of transfer to the ICU (6 vs. 12%, p = 0.0001, OR 0.38) and the hospital stay (9.3 vs. 12.1 days, p = 0.0001) were reduced in patients admitted to the RICU compared to those admitted to non-RICUs. Significant differences were found in care management concerning chest physiotherapy, mechanical ventilation, antibiotics, and corticosteroids.

CONCLUSIONS

The opening of a RICU may be advantageous to reduce in-hospital mortality, the need for ICU admission, and the hospital stay of patients with AECOPD, CAP, and ARF. Better use of care resources contributed to better patient management in the RICU.

Community-acquired pneumonia as medical emergency: predictors of early deterioration

BACKGROUND

Early organ dysfunction determines the prognosis of community-acquired pneumonia (CAP), and recognition of CAP as a medical emergency has been advocated.

OBJECTIVE

To characterise patients with 'emergency CAP' and evaluate predictors for very early organ failure or death.

METHODS

3427 prospectively enrolled patients of the CAPNETZ cohort were included. Emergency CAP was defined as requirement for mechanical ventilation or vasopressor support (MV/VS) or death within 72 h and 7 days after hospital admission, respectively. To determine independent predictors, multivariate Cox regression was employed. The ATS/IDSA 2007 minor criteria were evaluated for prediction of emergency CAP in patients without immediate need of MV/VS.

RESULTS

140 (4%) and 173 (5%) patients presented with emergency CAP within 3 and 7 days, respectively. Hospital mortality of patients presenting without immediate need of MV/VS was highest. Independent predictors of emergency CAP were the presence of focal chest signs, home oxygen therapy, multilobar infiltrates, altered mental status and altered vital signs (hypotension, raised respiratory or heart rate, hypothermia). The ATS/IDSA 2007 minor criteria showed a high sensitivity and negative predictive value, whereas the positive predictive value was low. Reduction to 6 minor criteria did not alter accuracy.

CONCLUSIONS

Emergency CAP is a rare but prognostic relevant condition, mortality is highest in patients presenting without immediate need of MV/VS. Vital sign abnormalities and parameters indicating acute organ dysfunction are independent predictors, and the ATS/IDSA 2007 minor criteria show a high negative predictive value.