Clinical challenge of diagnosing non-ventilator hospital-acquired pneumonia and identifying causative pathogens: a narrative review

Non-ventilated hospital-acquired pneumonia (NV-HAP) is associated with a significant healthcare burden, arising from high incidence and associated morbidity and mortality. However, accurate identification of cases remains challenging. At present, there is no gold-standard test for the diagnosis of NV-HAP, requiring instead the blending of non-specific signs and investigations. Causative organisms are only identified in a minority of cases. This has significant implications for surveillance, patient outcomes and antimicrobial stewardship. Much of the existing research in HAP has been conducted among ventilated patients. The paucity of dedicated NV-HAP research means that conclusions regarding diagnostic methods, pathology and interventions must largely be extrapolated from work in other settings. Progress is also limited by the lack of a widely agreed definition for NV-HAP. The diagnosis of NV-HAP has large scope for improvement. Consensus regarding a case definition will allow meaningful research to improve understanding of its aetiology and the heterogeneity of outcomes experienced by patients. There is potential to optimize the role of imaging and to incorporate novel techniques to identify likely causative pathogens. This would facilitate both antimicrobial stewardship and surveillance of an important healthcare-associated infection. This narrative review considers the utility of existing methods to diagnose NV-HAP, with a focus on the significance and challenge of identifying pathogens. It discusses the limitations in current techniques, and explores the potential of emergent molecular techniques to improve microbiological diagnosis and outcomes for patients.

Cardiovascular disease in Alpha 1 antitrypsin deficiency: an observational study assessing the role of neutrophil proteinase activity and the suitability of validated screening tools

BACKGROUND

Alpha 1 Antitrypsin Deficiency (AATD) is a rare, inherited lung disease which shares features with Chronic Obstructive Pulmonary Disease (COPD) but has a greater burden of proteinase related tissue damage. These proteinases are associated with cardiovascular disease (CVD) in the general population. It is unclear whether patients with AATD have a greater risk of CVD compared to usual COPD, how best to screen for this, and whether neutrophil proteinases are implicated in AATD-associated CVD. This study had three aims. To compare CVD risk in never-augmented AATD patients to non-AATD COPD and healthy controls (HC). To assess relationships between CVD risk and lung physiology. To determine if neutrophil proteinase activity was associated with CVD risk in AATD. Cardiovascular risk was assessed by QRISK2® score and aortic stiffness measurements using carotid-femoral (aortic) pulse wave velocity (aPWV). Medical history, computed tomography scans and post-bronchodilator lung function parameters were reviewed. Systemic proteinase 3 activity was measured. Patients were followed for 4 years, to assess CVD development.

RESULTS

228 patients with AATD, 50 with non-AATD COPD and 51 healthy controls were recruited. In all COPD and HC participants, QRISK2® and aPWV gave concordant results (with both measures either high or in the normal range). This was not the case in AATD. Once aPWV was adjusted for age and smoking history, aPWV was highest and QRISK2® lowest in AATD patients compared to the COPD or HC participants. Higher aPWV was associated with impairments in lung physiology, the presence of emphysema on CT scan and proteinase 3 activity following adjustment for age, smoking status and traditional CVD risk factors (using QRISK2® scores) in AATD. There were no such relationships with QRISK2® in AATD. AATD patients with confirmed CVD at four-year follow up had a higher aPWV but not QRISK2® at baseline assessment.

CONCLUSION

aPWV measured CVD risk is elevated in AATD. This risk is not captured by QRISK2®. There is a relationship between aPWV, lung disease and proteinase-3 activity. Proteinase-driven breakdown of elastin fibres in large arteries and lungs is a putative mechanism and forms a potential therapeutic target for CVD in AATD.

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Electronic prescribing systems as tools to improve patient care: a learning health systems approach to increase guideline concordant prescribing for venous thromboembolism prevention

BACKGROUND

Venous thromboembolism (VTE) causes significant mortality and morbidity in hospitalised patients. Risk factors for VTE are well known and there are validated risk assessment tools to support the use of prophylactic therapies. In England, reporting the percentage of patients with a completed VTE risk assessment is mandated, but this does not include whether that risk assessment resulted in appropriate prescribing. Full guideline compliance, defined as an assessment which led to an appropriate action-here prescribing prophylactic low molecular weight heparin where indicated, is rarely reported. Education, audit and feedback enhance guideline compliance but electronic prescribing systems (EPS) can mandate guideline-compliant actions. We hypothesised that a systems-based EPS intervention (prescribing rules which mandate approval or rejection of a proposed prescription of prophylactic low molecular weight heparin based on the mandated VTE assessment) would increase full VTE guideline compliance more than interventions which focused on targeting individual prescribers.

METHODS

All admitted patients within University Hospitals Birmingham NHS Foundation Trust were included for analysis between 2011 and 2020. The proportion of patients who received a fully compliant risk assessment and action was assessed over time. Interventions included teaching sessions and face-to-face feedback based on measured performance (an approach targeting individual prescribers) and mandatory risk assessment and prescribing rules into an EPS (a systems approach).

RESULTS

Data from all 235,005 admissions and all 5503 prescribers were included in the analysis. Risk assessments were completed in > 90-95% of all patients at all times, but full guideline compliance was lower (70% at the start of this study). Face-to-face feedback improved full VTE guideline compliance from 70 to 77% (p ≤ 0.001). Changes to the EPS to mandate assessment with prescribing rules increased full VTE compliance to 95% (p ≤ 0.001). Further amendments to the EPS system to reduce erroneous VTE assessments slightly reduced full compliance to 92% (p < 0.001), but this was then maintained including during changes to the low molecular weight heparin used for VTE prophylaxis.

DISCUSSION

An EPS-systems approach was more effective in improving sustained guideline-compliant VTE prevention over time. Non-compliance remained at 8-5% despite this mandated system. Further research is needed to assess the potential reasons for this.

Inflammation, Ageing and Diseases of the Lung: Potential therapeutic strategies from shared biological pathways

Lung diseases disproportionately affect elderly individuals. The lungs form a unique environment: a highly elastic organ with gaseous exchange requiring the closest proximity of inhaled air containing harmful agents and the circulating blood volume. The lungs are highly susceptible to senescence, with age and "inflammageing" creating a pro-inflammatory environment with a reduced capacity to deal with challenges. Whilst lung diseases may have disparate causes, the burden of ageing and inflammation provides a common process which can exacerbate seemingly unrelated pathologies. However, these shared pathways may also provide a common route to treatment, with increased interest in drugs which target ageing processes across respiratory diseases. In this review, we will examine the evidence for the increased burden of lung disease in older adults, the structural and functional changes seen with advancing age and assess what our expanding knowledge of inflammation and ageing pathways could mean for the treatment of lung disease.

Perceptions of anonymised data use and awareness of the NHS data opt-out amongst patients, carers and healthcare staff

BACKGROUND

England operates a National Data Opt-Out (NDOO) for the secondary use of confidential health data for research and planning. We hypothesised that public awareness and support for the secondary use of health data and the NDOO would vary by participant demography and healthcare experience. We explored patient/public awareness and perceptions of secondary data use, grouping potential researchers into National Health Service (NHS), academia or commercial. We assessed awareness of the NDOO system amongst patients, carers, healthcare staff and the public. We co-developed recommendations to consider when sharing unconsented health data for research.

METHODS

A patient and public engagement program, co-created and including patient and public workshops, questionnaires and discussion groups regarding anonymised health data use.

RESULTS

There were 350 participants in total. Central concerns for health data use included unauthorised data re-use, the potential for discrimination and data sharing without patient benefit. 94% of respondents were happy for their data to be used for NHS research, 85% for academic research and 68% by health companies, but less than 50% for non-healthcare companies and opinions varied with demography and participant group. Questionnaires showed that knowledge of the NDOO was low, with 32% of all respondents, 53% of all NHS staff and 29% of all patients aware of the NDOO. Recommendations to guide unconsented secondary health data use included that health data use should benefit patients; data sharing decisions should involve patients/public. That data should remain in close proximity to health services with the principles of data minimisation applied. Further, that there should be transparency in secondary health data use, including publicly available lists of projects, summaries and benefits. Finally, organisations involved in data access decisions should participate in programmes to increase knowledge of the NDOO, to ensure public members were making informed choices about their own data.

CONCLUSION

The majority of participants in this study reported that the use of healthcare data for secondary purposes was acceptable when accessed by NHS. Academic and health-focused companies. However, awareness was limited, including of the NDOO. Further development of publicly-agreed recommendations for secondary health data use may improve both awareness and confidence in secondary health data use.

The changing characteristics of COVID-19 presentations. A regional comparison of SARS-CoV-2 hospitalised patients during the first and second wave

BACKGROUND

This study assesses COVID-19 hospitalised patient demography and outcomes during wave 1 and wave 2, prior to new variants of the virus.

METHODS

All patients with a positive SARS-CoV-2 swab between 10th March 2020 and 5th July 2020 (wave 1) and 1st September 2020 and 16th November 2020 (wave 2) admitted to University Hospitals Birmingham NHS Foundation Trust were included (n=4856), followed for 28 days.

RESULTS

Wave 2 patients were younger, more ethnically diverse, had less co-morbidities and disease presentation was milder on presentation. After matching for these factors, mortality was reduced, but without differences in intensive care admissions.

CONCLUSION

Prior to new SARS-CoV-2 variants, outcomes for hospitalised patients with COVID-19 were improving but with similar intensive care needs.

Applying a COVID Virtual Ward model, assessing patient outcomes and staff workload

A COVID virtual ward (CVW) is recommended by NHS England, but 'usual care' outcomes have not been reported. A retrospective study of all adults with COVID-19 attending Queen Elizabeth Hospital Birmingham between 01/06/2020-31/01/2021, assessed against CVW criteria and followed for 28 days. Of 2301 COVID-19 patients, 571(25%) would have met CVW criteria. Of these, 325(57%) were discharged after review and 246(43%) admitted. Of admitted patients who met CVW criteria, 81% required hospital-supported therapies; 11% died. Of the 325 discharged, 13% re-presented, 9% with COVID-related symptoms, 2% required intensive care admission, and one died (0.3%). In this comparison, discharging patients without a CVW did not lead to more re-presentations, re-admissions, ITU escalations or deaths compared to published outcomes for hospitals with a CVW.

The evidence for assessing frailty and sarcopenia in an acute medical unit: a systematic review

BACKGROUND/OBJECTIVES

A systematic review was conducted to assess if frailty and sarcopenia were associated with poorer outcomes in older adults admitted to an acute medical unit (AMU).

METHODS

Eligible studies included older adults with an unplanned admission to an AMU and included a measure of frailty or sarcopenia, completed within 72 hours of admission. Risk of bias was assessed.

RESULTS

Of 1659 identified articles, 16 were included (4 on sarcopenia and 12 on frailty). There was significant study heterogeneity. Overall, frailty and sarcopenia were associated with worse outcomes. Targeted interventions appeared to improve outcomes.

CONCLUSION

Current evidence suggests some benefit in screening older adults admitted to an AMU for frailty and sarcopenia. However, further studies are required before clinical adoption.

Acute, non-COVID related medical admissions during the first wave of COVID-19: A retrospective comparison of changing patterns of disease

COVID-19 may have altered the case-mix of non-COVID acute medical admissions. Retrospective analysis of acute medical admissions to University Hospitals Birmingham NHS Foundation Trust, showed that medical admissions decreased in April 2020 compared to April 2019. The proportion of young adults, non-cardiac chest pain, musculoskeletal conditions and self-discharges decreased. The proportion of admissions due to alcohol misuse, psychiatric conditions, overdoses and falls increased. There were a higher number of patients admitted to ICU and greater inpatient mortality but not once COVID diagnoses were excluded. There was a significant change in hospitalised case-mix with conditions potentially reflecting social isolation increasing and diagnoses which rarely require hospital treatment, reducing. This analysis will help inform service planning.

Described Practices for Assessing Fluid Resuscitation in Acute Hospital Care: A Qualitative Study

Fluid resuscitation is a widely-used treatment in acute and emergency medicine, however, the process used to perform a fluid assessment has never been studied. This qualitative study explored how acute physicians describe their approach to assessing for fluid resuscitation. 18 clinicians of varying grades consented to a semi-structured interview. Transcripts were coded and analysed using thematic analysis. Participants described three subtypes of assessment; screening assessment, emergency assessment and formal assessment. Whether a patient was 'sick' was key to determining which assessment they would receive. Marked heterogeneity was noted in the assessment processes, particularly regarding the use of history-taking. Further research is required to determine how the information gathered in these assessments is used to decide when fluid resuscitation is indicated.

Neutrophil chemotaxis in granulomatosis with polyangiitis (Wegener's) and idiopathic pulmonary fibrosis

The presence of antineutrophil cytoplasmic antibodies in granulomatosis with polyangiitis (Wegener's) (GPA) implicates the neutrophil as a key effector cell. Previous studies have reported elevated neutrophil counts in the lung, although the determinants of neutrophil chemotaxis in the GPA lung are unknown. Bronchoalveolar lavage fluid (BALF) cell counts, myeloperoxidase (MPO) and chemokines were measured in 27 patients with GPA, 20 disease controls with idiopathic pulmonary fibrosis (IPF) and six healthy controls. CXC chemokine ligand (CXCL)8, interleukin (IL)-1β, epithelial neutrophil-activating protein 78, granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor were measured by ELISA. The neutrophil chemotactic potential of BALF was investigated using the under-agarose method, and specific antibodies were used to examine the role of CXCL8 and IL-1β. GPA BALF had an increased neutrophil percentage, and elevated MPO, CXCL8 and G-CSF concentrations compared with healthy controls. Chemotaxis of control neutrophils towards BALF from patients with active (p=0.006) and remission (p=0.077) GPA, and IPF (p=0.001) patients was increased compared with normal controls. BALF-induced chemotaxis correlated with BALF IL-1β (r=0.761, p=0.001) and CXCL8 (r=0.640, p=0.012) in GPA, and was inhibited by anti-CXCL8 (85%; p<0.001) and anti-IL-1β (69%; p<0.001). Our study confirms a neutrophilia and pro-inflammatory alveolar milieu that persists in clinical remission. CXCL8 and IL-1β appear to play important roles in the neutrophil chemotactic response to BALF.

Inter-relationships between inflammatory markers in patients with stable COPD with bronchitis: intra-patient and inter-patient variability

BACKGROUND

Measurements of pulmonary biomarkers can be used to monitor airway inflammation in chronic obstructive pulmonary disease (COPD), but the variability of sampled biomarkers and their inter-relationships are poorly understood. A study was undertaken to examine the intra- and inter-patient variability in spontaneous sputum samples from patients in the stable state and to describe the relationship between biomarkers, cell counts and markers of disease.

METHODS

Sputum interleukin-1beta, tumour necrosis factor alpha, interleukin 8, myeloperoxidase, leucotriene B4, growth-related oncogene alpha and differential cell counts were measured in patients with moderate to severe stable COPD (n = 14) on 11 occasions over a 1-month period.

RESULTS

There was significant variability in all inflammatory indices (median intra-patient coefficient of variation (CV) 35% (IQR 22-69), median inter-patient CV 102% (IQR 61-145)). Variability could be reduced by using a rolling mean of individual patient data points. Sample size calculations were undertaken to determine the number of patients required to detect a 50% reduction in neutrophil count. Using a crossover design of a putative effective treatment, the number needed using one data point per patient was 72, reducing to 23 when a mean of three data points was used. Significant correlations were demonstrated both between the inflammatory biomarkers themselves and between inflammatory biomarkers and markers of disease. Some relationships were not apparent when results from a single sample were used. The reliability of inter-relationships improved as more data points were used for each patient.

CONCLUSIONS

Clear relationships exist between inflammatory biomarkers in patients with stable COPD. Sequential sampling reduced the variability of individual mediators and the potential number of patients needed to power proof of concept interventional studies.

COPD exacerbations . 2: aetiology

Exacerbations of COPD are thought to be caused by complex interactions between the host, bacteria, viruses, and environmental pollution. These factors increase the inflammatory burden in the lower airways, overwhelming the protective anti-inflammatory defences leading to tissue damage. Frequent exacerbations are associated with increased morbidity and mortality, a faster decline in lung function, and poorer health status, so prevention or optimal treatment of exacerbations is a global priority. In order to evolve new treatment strategies there has been great interest in the aetiology and pathophysiology of exacerbations, but progress has been hindered by the heterogeneous nature of these episodes, vague definitions of an exacerbation, and poor stratification of known confounding factors when interpreting results. We review how an exacerbation should be defined, its inflammatory basis, and the importance of exacerbations on disease progression. Important aetiologies, with their potential underlying mechanisms, are discussed and the significance of each aetiology is considered.

Senescence in innate immune responses: reduced neutrophil phagocytic capacity and CD16 expression in elderly humans

Elderly humans are more susceptible to bacterial infections because of declining immune status. We have investigated the effect of aging on neutrophil bactericidal responses, comparing neutrophil function in healthy, young (23-35 years) and elderly (>65 years) volunteers. Superoxide generation in response to fMLP was slightly increased in neutrophils from elderly donors, and serum from the elderly was able to opsonize E. coli efficiently. In contrast, phagocytic index was significantly lower in neutrophils from the elderly, compared with young donors (P<0.005). CD11a and CD11b expression was not affected by age, but CD16 was significantly reduced in neutrophils from elderly donors (P<0.0001). CD16 expression and phagocytic index were measured in the same neutrophils using FITC-labeled E. coli, PE-conjugated anti-CD16 antibody, and CD16 expression correlated with phagocytic index (r=0.83; P<0.05). In elderly patients with bacterial infection, CD16 expression remained low. We propose that reduced neutrophil CD16 expression and phagocytosis contribute to human immunesenescence.