Validity of the diagnosis of pneumonia in hospitalised patients with COPD

Advancements and challenges in the management of pneumonia in elderly patients with COPD

INTRODUCTION

Chronic Obstructive Pulmonary Disease (COPD) significantly predisposes the elderly to pneumonia, presenting a complex interplay of pulmonary dysfunction and infection risk.

AREAS COVERED

This article reviews the substantial epidemiologic impact, elucidates the interlinked pathophysiology of COPD and pneumonia, and examines the microbial landscape shaping infection in these patients. It also evaluates management protocols and the multifaceted clinical challenges encountered during treatment.

EXPERT OPINION

Delving into the latest research, we underscore the criticality of preventive measures such as vaccination and present an integrated approach to managing Community-Acquired Pneumonia (CAP) in the COPD demographic. The review also proposes strategic directions for future investigations aimed at enhancing patient outcomes through a deeper understanding of the COPD-pneumonia nexus.

Spectrum and antimicrobial resistance in acute exacerbation of chronic obstructive pulmonary disease with pneumonia: a cross-sectional prospective study from Vietnam

BACKGROUND

Respiratory infections have long been recognized as a primary cause of acute exacerbation of chronic obstructive pulmonary disease (AE-COPD). Additionally, the emergence of antimicrobial resistance has led to an urgent and critical situation in developing countries, including Vietnam. This study aimed to investigate the distribution and antimicrobial resistance of bacteria in patients with AE-COPD using both conventional culture and multiplex real-time PCR. Additionally, associations between clinical characteristics and indicators of pneumonia in these patients were examined.

METHODS

This cross-sectional prospective study included 92 AE-COPD patients with pneumonia and 46 without pneumonia. Sputum specimens were cultured and examined for bacterial identification, and antimicrobial susceptibility was determined for each isolate. Multiplex real-time PCR was also performed to detect ten bacteria and seven viruses.

RESULTS

The detection rates of pathogens in AE-COPD patients with pneumonia were 92.39%, compared to 86.96% in those without pneumonia. A total of 26 pathogenic species were identified, showing no significant difference in distribution between the two groups. The predominant bacteria included Klebsiella pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae, followed by Acinetobacter baumannii and Streptococcus mitis. There was a slight difference in antibiotic resistance between bacteria isolated from two groups. The frequency of H. influenzae was notably greater in AE-COPD patients who experienced respiratory failure (21.92%) than in those who did not (9.23%). S. pneumoniae was more common in patients with stage I (44.44%) or IV (36.36%) COPD than in patients with stage II (17.39%) or III (9.72%) disease. ROC curve analysis revealed that C-reactive protein (CRP) levels could distinguish patients with AE-COPD with and without pneumonia (AUC = 0.78).

CONCLUSION

Gram-negative bacteria still play a key role in the etiology of AE-COPD patients, regardless of the presence of pneumonia. This study provides updated evidence for the epidemiology of AE-COPD pathogens and the appropriate selection of antimicrobial agents in Vietnam.

Accuracy of the recording of pneumonia events in English electronic healthcare record data in patients with chronic obstructive pulmonary disease

BACKGROUND

In primary care, identifying pneumonia events in people with chronic obstructive pulmonary disease (COPD) may be challenging due to similarities in symptoms with COPD exacerbations and lack of diagnostic testing. This study explored the accuracy of pneumonia diagnosis coded in primary care by comparing diagnosis in primary care with diagnosis in hospital.

METHODS

A study population of people with COPD in England was created using the Clinical Practice Research Datalink Aurum database linked with Hospital Episode Statistics inpatient data. Pneumonia codes only, and pneumonia code with associated clinical and/or treatment codes (chest x-ray, symptoms, antibiotics, sputum and blood culture) were used to determine pneumonia events in primary care. Events that were followed by hospitalisation within 7 days were used to estimate the positive predictive value (PPV) of pneumonia coding in primary care, using primary diagnosis of pneumonia in secondary care as the gold standard. The PPV of primary care recording of hospitalised pneumonia was also calculated.

RESULTS

Two hundred seventy-four thousand one hundred fifty-six COPD patients were eligible for inclusion, of whom 7,560 had an eligible pneumonia event in primary care diagnosed between 2015-2019 which was not 'hospital-acquired' and was diagnosed and entered on the same day. Of the 2,094 events which were followed by hospitalisation within 7 days, 1,208 had a primary diagnosis of pneumonia in hospital, representing a PPV of pneumonia coding in primary care of 57.7% (95% CI 55.6%-59.8%). Another 284 (13.6%) were diagnosed as a COPD exacerbation and 114 (5.4%) were diagnosed as another respiratory disease. Use of additional pneumonia clinical and treatment codes had a modest effect on the PPV but substantially lowered the number of events. Of the 33,603 eligible pneumonia events identified in secondary care, only 11,445 were recorded in primary care within 42 days, representing a sensitivity of 34.1% (95% CI 33.6%-34.6%).

CONCLUSIONS

Use of primary care pneumonia codes and associated clinical and treatment codes to determine pneumonia is not recommended due to significant levels of misdiagnosis and many hospitalised events failing to be recorded in primary care.

A mRNA panel for differentiation between acute exacerbation or pneumonia in COPD patients

Introduction

Patients suffering from chronic obstructive pulmonary disease (COPD) are prone to acute exacerbations (AECOPD) or community acquired pneumonia (CAP), both posing severe risk of morbidity and mortality. There is no available biomarker that correctly separates AECOPD from COPD. However, because CAP and AECOPD differ in aetiology, treatment and prognosis, their discrimination would be important.

Methods

This study analysed the ability of selected candidate transcripts from peripheral blood mononuclear cells (PBMCs) to differentiate between patients with AECOPD, COPD & CAP, and CAP without pre-existing COPD.

Results

In a previous study, we identified differentially regulated genes between CAP and AECOPD in PBMCs. In the present new cohort, we tested the potential of selected candidate PBMC transcripts to differentiate at early time points AECOPD, CAP+COPD, and CAP without pre-existing COPD. Expression of YWHAG, E2F1 and TDRD9 held predictive power: This gene set predicted diseases markedly better (model accuracy up to 100%) than classical clinical markers like CRP, lymphocyte count and neutrophil count (model accuracy up to 82%).

Discussion

In summary, in our cohort expression levels of YWHAG, E2F1 and TDRD9 differentiated with high accuracy between COPD patients suffering from acute exacerbation or CAP.

Transcriptomic characterization of the human segmental endotoxin challenge model

Segmental instillation of lipopolysaccharide (LPS) by bronchoscopy safely induces transient airway inflammation in human lungs. This model enables investigation of pulmonary inflammatory mechanisms as well as pharmacodynamic analysis of investigational drugs. The aim of this work was to describe the transcriptomic profile of human segmental LPS challenge with contextualization to major respiratory diseases. Pre-challenge bronchoalveolar lavage (BAL) fluid and biopsies were sampled from 28 smoking, healthy participants, followed by segmental instillation of LPS and saline as control. Twenty-four hours post instillation, BAL and biopsies were collected from challenged lung segments. Total RNA of cells from BAL and biopsy samples were sequenced and analysed for differentially expressed genes (DEGs). After challenge with LPS compared with saline, 6316 DEGs were upregulated and 241 were downregulated in BAL, but only one DEG was downregulated in biopsy samples. Upregulated DEGs in BAL were related to molecular functions such as "Inflammatory response" or "chemokine receptor activity", and upregulated pro-inflammatory pathways such as "Wnt-"/"Ras-"/"JAK-STAT" "-signaling pathway". Furthermore, the segmental LPS challenge model resembled aspects of the five most prevalent respiratory diseases chronic obstructive pulmonary disease (COPD), asthma, pneumonia, tuberculosis and lung cancer and featured similarities with acute exacerbations in COPD (AECOPD) and community-acquired pneumonia. Overall, our study provides extensive information about the transcriptomic profile from BAL cells and mucosal biopsies following LPS challenge in healthy smokers. It expands the knowledge about the LPS challenge model providing potential overlap with respiratory diseases in general and infection-triggered respiratory insults such as AECOPD in particular.

Comparison of CRP, Procalcitonin, Neutrophil Counts, Eosinophil Counts, sTREM-1, and OPN between Pneumonic and Nonpneumonic Exacerbations in COPD Patients

Introduction

The patients with community-acquired pneumonia (CAP) and acute exacerbations of COPD (AECOPD) could have a higher risk of acute and severe respiratory illness than those without CAP in AECOPD. Consequently, early identification of pneumonia in AECOPD is quite important. Methods. 52 subjects with AECOPD + CAP and 93 subjects with AECOPD from two clinical centers were enrolled in this prospective observational study. The values of osteopontin (OPN), soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), C-reactive protein (CRP), procalcitonin (PCT), eosinophil (EOS) counts, and neutrophil (Neu) counts in blood on the first day of admission and clinical symptoms were compared in AECOPD and AECOPD + CAP. In addition, subgroup analyses of biomarker difference were conducted based on the current use of inhaled glucocorticoids (ICS) or systemic corticosteroids (SCS).

Results

Patients with AECOPD + CAP had increased sputum volume, sputum purulence, diabetes mellitus, and longer hospital stays than AECOPD patients (p < 0.05). A clinical logistic regression model showed among the common clinical symptoms, purulent sputum can independently predict pneumonia in AECOPD patients after adjusting for a history of diabetes. At day 1, AECOPD + CAP patients had higher values of Neu, CRP, PCT, and OPN, while serum sTREM-1 levels and EOS counts were similar in the two groups. CRP fared best at predicting AECOPD with CAP (p < 0.05 for the test of difference), while OPN had similar accuracy with Neu, PCT, and purulent sputum (p > 0.05 for the test of difference). Multivariate analysis, including clinical symptoms and biomarkers, suggested that CRP ≥15.8 mg/dL at day 1 was a only promising predictor of pneumonia in AECOPD. CRP and OPN were not affected by ICS or SCS.

Conclusions

CRP ≥15.8 mg/dL is an ideal promising predictor of pneumonia in AECOPD, and its plasma level is not affected by ICS or SCS. The diagnostic performance of CRP is not significantly improved when combined with clinical symptoms or other markers (OPN, PCT, and Neu).

Sphingosine-1-phosphate and CRP as potential combination biomarkers in discrimination of COPD with community-acquired pneumonia and acute exacerbation of COPD

Background

 Chronic obstructive pulmonary disease (COPD) is a significant public health concern. The patients with acute exacerbations of COPD (AECOPD) and pneumonia have similar clinical presentations. The use of conventional diagnostic markers, such as complete blood count with differential and C-reactive protein (CRP), is the current mainstream method for differentiating clinically relevant pneumonia from other mimics. However, those conventional methods have suboptimal sensitivity and specificity for patients with a clinical suspicion of infection. The limitations often cause the ambiguity of the initiation of antibiotic treatment. Recently, our pilot study suggested that the patients with pneumonia have significantly higher plasma Sphingosine-1-phosphate (S1P) levels than controls. The initial findings suggest that plasma S1P is a potential biomarker for predicting prognosis in pneumonia. The aim of this study was to evaluate the value of S1P and CRP for discriminating COPD with pneumonia and AECOPD in an Emergency Department (ED) setting.

Methods

 Patients diagnosed with AECOPD or COPD with pneumonia were recruited from the Emergency Department of Wan Fang Hospital. The clinical data, demographics, and blood samples were collected upon ED admission. The concentration of plasma S1P was measured by ELISA.

Results

 Thirty-nine patients with AECOPD and 78 with COPD plus pneumonia were enrolled in this observational study. The levels of blood S1P and CRP were significantly higher in patients with COPD plus CAP compared to those in AE COPD patients. The area under the receiver operator characteristic (ROC) curve for the S1P and CRP for distinguishing between patients with COPD plus CAP and AECOPD is 0.939 (95% CI: 0.894–0.984) and 0.886 (95% CI: 0.826–0.945), whereas the combination of S1P and CRP yielded a value of 0.994 (95% CI: 0.897–1.000). By comparing with CRP or S1P, combining CRP and S1P had significantly higher AUC value for differentiating between the COPD with pneumonia group and the AECOPD group.

Conclusions

Our findings suggest that S1P is a potential diagnostic biomarker in distinguishing COPD with CAP from AECOPD. Additionally, the diagnostic ability of S1P can be improved when used in combination with CRP.

Hospital Variation in Non-Invasive Ventilation Use for Acute Respiratory Failure Due to COPD Exacerbation

Background

Non-invasive mechanical ventilation (NIV) use in patients admitted with acute respiratory failure due to COPD exacerbations (AECOPDs) varies significantly between hospitals. However, previous literature did not account for patients’ illness severity. Our objective was to examine the variation in risk-standardized NIV use after adjusting for illness severity.

Methods

We retrospectively analyzed AECOPD hospitalizations from 2011 to 2017 at 106 acute-care Veterans Health Administration (VA) hospitals in the USA. We stratified hospitals based on the percentage of NIV use among patients who received ventilation support within the first 24 hours of admission into quartiles, and compared patient characteristics. We calculated the risk-standardized NIV % using hierarchical models adjusting for comorbidities and severity of illness. We then stratified the hospitals by risk-standardized NIV % into quartiles and compared hospital characteristics between quartiles. We also compared the risk-standardized NIV % between rural and urban hospitals.

Results

In 42,048 admissions for AECOPD over 6 years, the median risk-standardized initial NIV % was 57.3% (interquartile interval [IQI]=41.9–64.4%). Hospitals in the highest risk-standardized NIV % quartiles cared for more rural patients, used invasive ventilators less frequently, and had longer length of hospital stay, but had no difference in mortality relative to the hospitals in the lowest quartiles. The risk-standardized NIV % was 65.3% (IQI=34.2–84.2%) in rural and 55.1% (IQI=10.8–86.6%) in urban hospitals (p=0.047), but hospital mortality did not differ between the two groups.

Conclusion

NIV use varied significantly across hospitals, with rural hospitals having higher risk-standardized NIV % rates than urban hospitals. Further research should investigate the exact mechanism of variation in NIV use between rural and urban hospitals.

Effectiveness and Safety of COPD Maintenance Therapy with Tiotropium/Olodaterol versus LABA/ICS in a US Claims Database

Introduction

In patients with chronic obstructive pulmonary disease (COPD), treatment with long-acting muscarinic antagonist (LAMA)/long-acting β₂-agonist (LABA) combination therapy significantly improves lung function versus LABA/inhaled corticosteroid (ICS). To investigate whether LAMA/LABA could provide better clinical outcomes than LABA/ICS, this non-interventional database study assessed the risk of COPD exacerbations, pneumonia, and escalation to triple therapy in patients with COPD initiating maintenance therapy with tiotropium/olodaterol versus any LABA/ICS combination.

Methods

Administrative healthcare claims and laboratory results data from the US HealthCore Integrated Research Database^sm were evaluated for patients with COPD initiating tiotropium/olodaterol versus LABA/ICS treatment (January 2013–March 2019). Patients were aged at least 40 years with a diagnosis of COPD (but not asthma) at cohort entry. A Cox proportional hazard regression model was used (as-treated analysis) to assess risk of COPD exacerbation, community-acquired pneumonia, and escalation to triple therapy, both individually and as a combined risk of any one of these events. Potential imbalance of confounding factors between cohorts was handled using fine stratification, reweighting, and trimming by exposure propensity score (high-dimensional); subgroup analyses were conducted on the basis of blood eosinophil levels and exacerbation history.

Results

The total population consisted of 61,985 patients (tiotropium/olodaterol n = 2684; LABA/ICS n = 59,301); after reweighting, the total was 42,953 patients (tiotropium/olodaterol n = 2600; LABA/ICS n = 40,353; mean age 65 years; female 54.5%). Patients treated with tiotropium/olodaterol versus LABA/ICS experienced a reduction in the risk of COPD exacerbations (adjusted hazard ratio 0.76 [95% confidence interval 0.68, 0.85]), pneumonia (0.74 [0.57, 0.97]), escalation to triple therapy (0.22 [0.19, 0.26]), and any one of these events (0.45 [0.41, 0.49]); the combined risk was similar irrespective of baseline eosinophils and exacerbation history.

Conclusions

In patients with COPD, tiotropium/olodaterol was associated with a lower risk of COPD exacerbations, pneumonia, and escalation to triple therapy versus LABA/ICS, both individually and in combination; the combined risk was reduced irrespective of baseline eosinophils or exacerbation history.

Trial Registration

ClinicalTrials.gov identifier, NCT04138758 (registered 23 October 2019).

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01646-5.

The diagnostic accuracy of pre-hospital assessment of acute respiratory failure

Introduction:

Acute respiratory failure (ARF) is a common medical emergency. Pre-hospital management includes controlled oxygen therapy, supplemented by specific management options directed at the underlying disease. The aim of the current study was to characterise the accuracy of paramedic diagnostic assessment in acute respiratory failure.

Methods:

A nested diagnostic accuracy and agreement study comparing pre-hospital clinical impression to the final hospital discharge diagnosis was conducted as part of the ACUTE (Ambulance CPAP: Use, Treatment effect and Economics) trial. Adults with suspected ARF were recruited from the UK West Midlands Ambulance Service. The pre-hospital clinical impression of the recruiting ambulance service clinician was prospectively recorded and compared to the final hospital diagnosis at 30 days. Agreement between pre-hospital and hospital diagnostic assessments was evaluated using raw agreement and Gwets AC1 coefficient.

Results:

77 participants were included. Chronic obstructive pulmonary disease (32.9%) and lower respiratory tract infection (32.9%) were the most frequently suspected primary pre-hospital diagnoses for ARF, with secondary contributory conditions recorded in 36 patients (46.8%). There was moderate agreement between the primary pre-hospital and hospital diagnoses, with raw agreement of 58.5% and a Gwets AC1 coefficient of 0.56 (95% CI 0.43 to 0.69). In five cases, a non-respiratory final diagnosis was present, including: myocardial infarction, ruptured abdominal aortic aneurysm, liver failure and sepsis.

Conclusions:

Pre-hospital assessment of ARF is challenging, with limited accuracy compared to the final hospital diagnosis. A syndromic approach, providing general supportive care, rather than a specifically disease-orientated treatment strategy, is likely to be most appropriate for the pre-hospital environment.

Understanding the impact of chronic obstructive pulmonary disease exacerbations on patient health and quality of life

Exacerbations of chronic obstructive pulmonary disease (COPD) represent a significant clinical problem, and are associated with decreased lung function, worsening quality of life and decreased physical activity levels, with even a single exacerbation having detrimental effects. The occurrence of COPD exacerbations can also have a considerable impact on healthcare costs and mortality rates, with over one-fifth of patients hospitalized for a COPD exacerbation for the first time dying within one year of discharge. This highlights the need for COPD exacerbations to be a major focus in clinical practice. Furthermore, the substantial effect that COPD exacerbations can have on patient mental health should not be underestimated. Despite their clinical importance, COPD exacerbations are poorly recognized and reported by patients, and improving patient understanding and reporting of exacerbations to ensure prompt treatment may minimize their deleterious effects. Renewed focus on improving current clinical practice with support from evidence-based guidelines is required. This also raises a challenge to payors, healthcare systems and government policies to do more to tackle the considerable outstanding burden of COPD exacerbations.

Impact of Hyponatremia on COPD Exacerbation Prognosis

The most common electrolyte disorder among hospitalized patients, hyponatremia is a predictor of poor prognosis in various diseases. The aim of this study was to establish the prevalence of hyponatremia in patients admitted for acute exacerbation of chronic obstructive pulmonary disease (AECOPD), as well as its association with poor clinical progress. Prospective observational study carried out from 1 October 2016 to 1 October 2018 in the following hospitals: Salnés in Vilagarcía de Arousa, Arquitecto Marcide in Ferrol, and the University Hospital Complex of Santiago de Compostela, Galicia, Spain, on patients admitted for AECOPD. Patient baseline treatment was identified, including hyponatremia-inducing drugs. Poor progress was defined as follows: prolonged stay, death during hospitalization, or readmission within one month after the index episode discharge. 602 patients were enrolled, 65 cases of hyponatremia (10.8%) were recorded, all of a mild nature (mean 131.6; SD 2.67). Of all the patients, 362 (60%) showed poor progress: 18 (3%) died at admission; 327 (54.3%) had a prolonged stay; and 91 (15.1%) were readmitted within one month after discharge. Patients with hyponatremia had a more frequent history of atrial fibrillation (AF) (p 0.005), pleural effusion (p 0.01), and prolonged stay (p 0.01). The factors independently associated with poor progress were hyponatremia, pneumonia, and not receiving home O₂ treatment prior to admission. Hyponatremia is relatively frequent in patients admitted for AECOPD, and it has important prognostic implications, even when mild in nature.

Pneumonia in exacerbations of COPD: what is the clinical significance?

Does it matter if a patient presenting with an exacerbation of COPD (ECOPD) is found to have consolidation on imaging? In the 2010 European COPD Audit, which included 14 111 patients from 384 hospitals in 13 countries with a primary discharge diagnosis of ECOPD, ∼20% had concomitant consolidation on admission chest radiography [1]. Crucially, the presence of consolidation was associated with increased 90-day mortality in this cohort (adjusted OR 1.36, 95% CI 1.2–1.55) [1]. Similar findings were seen in the large 2014 UK National COPD Audit, which found that ECOPD patients with consolidation experienced increased in-hospital mortality (6.7% versus 3.6%, p<0.001) and increased 90-day mortality (15.9% versus 10.8%, p<0.001) compared to patients without consolidation [2].

It is vital that clinicians identify radiological consolidation in hospitalised COPD patients, as this confers an increased mortality risk, has important implications for risk stratification and influences managementhttp://bit.ly/2q2vH2J

Transcriptional analysis identifies potential biomarkers and molecular regulators in pneumonia and COPD exacerbation

Lower respiratory infections, such as community-acquired pneumonia (CAP), and chronic obstructive pulmonary disease (COPD) rank among the most frequent causes of death worldwide. Improved diagnostics and profound pathophysiological insights are urgent clinical needs. In our cohort, we analysed transcriptional networks of peripheral blood mononuclear cells (PBMCs) to identify central regulators and potential biomarkers. We investigated the mRNA- and miRNA-transcriptome of PBMCs of healthy subjects and patients suffering from CAP or AECOPD by microarray and Taqman Low Density Array. Genes that correlated with PBMC composition were eliminated, and remaining differentially expressed genes were grouped into modules. One selected module (120 genes) was particularly suitable to discriminate AECOPD and CAP and most notably contained a subset of five biologically relevant mRNAs that differentiated between CAP and AECOPD with an AUC of 86.1%. Likewise, we identified several microRNAs, e.g. miR-545-3p and miR-519c-3p, which separated AECOPD and CAP. We furthermore retrieved an integrated network of differentially regulated mRNAs and microRNAs and identified HNF4A, MCC and MUC1 as central network regulators or most important discriminatory markers. In summary, transcriptional analysis retrieved potential biomarkers and central molecular features of CAP and AECOPD.