Sepsis and case fatality rates and associations with deprivation, ethnicity, and clinical characteristics: population-based case-control study with linked primary care and hospital data in England.

PURPOSE: Sepsis is a life-threatening organ dysfunction caused by dysregulated host response to infection. The purpose of the study was to measure the associations of specific exposures (deprivation, ethnicity, and clinical characteristics) with incident sepsis and case fatality. METHODS: Two research databases in England were used including anonymized patient-level records from primary care linked to hospital admission, death certificate, and small-area deprivation. Sepsis cases aged 65-100 years were matched to up to six controls. Predictors for sepsis (including 60 clinical conditions) were evaluated using logistic and random forest models; case fatality rates were analyzed using logistic models. RESULTS: 108,317 community-acquired sepsis cases were analyzed. Severe frailty was strongly associated with the risk of developing sepsis (crude odds ratio [OR] 14.93; 95% confidence interval [CI] 14.37-15.52). The quintile with most deprived patients showed an increased sepsis risk (crude OR 1.48; 95% CI 1.45-1.51) compared to least deprived quintile. Strong predictors for sepsis included antibiotic exposure in prior 2 months, being house bound, having cancer, learning disability, and diabetes mellitus. Severely frail patients had a case fatality rate of 42.0% compared to 24.0% in non-frail patients (adjusted OR 1.53; 95% CI 1.41-1.65). Sepsis cases with recent prior antibiotic exposure died less frequently compared to non-users (adjusted OR 0.7; 95% CI 0.72-0.76). Case fatality strongly decreased over calendar time. CONCLUSION: Given the variety of predictors and their level of associations for developing sepsis, there is a need for prediction models for risk of developing sepsis that can help to target preventative antibiotic therapy.

Covariates in population pharmacokinetic studies of critically ill adults receiving ß-lactam antimicrobials: a systematic review and narrative synthesis.

Introduction: Population pharmacokinetic studies of ß-lactam antimicrobials in critically ill patients derive models that inform their dosing. In non-linear mixed-effects modelling, covariates are often used to improve model fit and explain variability. We aimed to investigate which covariates are most commonly assessed and which are found to be significant, along with global patterns of publication. Methods: We conducted a systematic review, searching MEDLINE, Embase, CENTRAL and Web of Science on 01 March 2023, including studies of critically ill adults receiving ß-lactam antimicrobials who underwent blood sampling for population pharmacokinetic studies. We extracted and categorized all reported covariates and assessed reporting quality using the ClinPK checklist. Results: Our search identified 151 studies with 6018 participants. Most studies reported observational cohorts (120 studies, 80%), with the majority conducted in high-income settings (136 studies, 90%). Of the 1083 identified covariate instances, 237 were unique; the most common categories were patient characteristics (n = 404), biomarkers (n = 206) and physiological parameters (n = 163). Only seven distinct commonly reported covariates (CLCR, weight, glomerular filtration rate, diuresis, need for renal replacement, serum albumin and C-reactive protein) were significant more than 20% of the time. Conclusions: Covariates are most commonly chosen based on biological plausibility, with patient characteristics and biomarkers the most frequently investigated. We developed an openly accessible database of reported covariates to aid investigators with covariate selection when designing population pharmacokinetic studies. Novel covariates, such as sepsis subphenotypes, have not been explored yet, leaving a research gap for future work.

Alpha 2 agonists for sedation to produce better outcomes from critical illness (A2B Trial): protocol for a multicentre phase 3 pragmatic clinical and cost-effectiveness randomised trial in the UK.

INTRODUCTION: Almost all patients receiving mechanical ventilation (MV) in intensive care units (ICUs) require analgesia and sedation. The most widely used sedative drug is propofol, but there is uncertainty whether alpha2-agonists are superior. The alpha 2 agonists for sedation to produce better outcomes from critical illness (A2B) trial aims to determine whether clonidine or dexmedetomidine (or both) are clinically and cost-effective in MV ICU patients compared with usual care. METHODS AND ANALYSIS: Adult ICU patients within 48 hours of starting MV, expected to require at least 24 hours further MV, are randomised in an open-label three arm trial to receive propofol (usual care) or clonidine or dexmedetomidine as primary sedative, plus analgesia according to local practice. Exclusions include patients with primary brain injury; postcardiac arrest; other neurological conditions; or bradycardia. Unless clinically contraindicated, sedation is titrated using weight-based dosing guidance to achieve a Richmond-Agitation-Sedation score of -2 or greater as early as considered safe by clinicians. The primary outcome is time to successful extubation. Secondary ICU outcomes include delirium and coma incidence/duration, sedation quality, predefined adverse events, mortality and ICU length of stay. Post-ICU outcomes include mortality, anxiety and depression, post-traumatic stress, cognitive function and health-related quality of life at 6-month follow-up. A process evaluation and health economic evaluation are embedded in the trial.The analytic framework uses a hierarchical approach to maximise efficiency and control type I error. Stage 1 tests whether each alpha2-agonist is superior to propofol. If either/both interventions are superior, stages 2 and 3 testing explores which alpha2-agonist is more effective. To detect a mean difference of 2 days in MV duration, we aim to recruit 1437 patients (479 per group) in 40-50 UK ICUs. ETHICS AND DISSEMINATION: The Scotland A REC approved the trial (18/SS/0085). We use a surrogate decision-maker or deferred consent model consistent with UK law. Dissemination will be via publications, presentations and updated guidelines. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT03653832.

Developing a model for decision-making around antibiotic prescribing for patients with COVID-19 pneumonia in acute NHS hospitals during the first wave of the COVID-19 pandemic: qualitative results from the Procalcitonin Evaluation of Antibiotic use in COVID-19 Hospitalised patients (PEACH Study).

OBJECTIVE: To explore and model factors affecting antibiotic prescribing decision-making early in the pandemic. DESIGN: Semistructured qualitative interview study. SETTING: National Health Service (NHS) trusts/health boards in England and Wales. PARTICIPANTS: Clinicians from NHS trusts/health boards in England and Wales. METHOD: Individual semistructured interviews were conducted with clinicians in six NHS trusts/health boards in England and Wales as part of the Procalcitonin Evaluation of Antibiotic use in COVID-19 Hospitalised patients study, a wider study that included statistical analysis of procalcitonin (PCT) use in hospitals during the first wave of the pandemic. Thematic analysis was used to identify key factors influencing antibiotic prescribing decisions for patients with COVID-19 pneumonia during the first wave of the pandemic (March to May 2020), including how much influence PCT test results had on these decisions. RESULTS: During the first wave of the pandemic, recommendations to prescribe antibiotics for patients with COVID-19 pneumonia were based on concerns about secondary bacterial infections. However, as clinicians gained more experience with COVID-19, they reported increasing confidence in their ability to distinguish between symptoms and signs caused by SARS-CoV-2 viral infection alone, and secondary bacterial infections. Antibiotic prescribing decisions were influenced by factors such as clinician experience, confidence, senior support, situational factors and organisational influences. A decision-making model was developed. CONCLUSION: This study provides insight into the decision-making process around antibiotic prescribing for patients with COVID-19 pneumonia during the first wave of the pandemic. The importance of clinician experience and of senior review of decisions as factors in optimising antibiotic stewardship is highlighted. In addition, situational and organisational factors were identified that could be optimised. The model presented in the study can be used as a tool to aid understanding of the complexity of the decision-making process around antibiotic prescribing and planning antimicrobial stewardship support in the context of a pandemic. TRIAL REGISTRATION NUMBER: ISRCTN66682918.

Clinical trials of pneumonia management assess heterogeneous outcomes and measurement instruments.

OBJECTIVES: To inform clinical practice guidelines, randomized controlled trials (RCTs) of the management of pneumonia need to address the outcomes that are most important to patients and health professionals using consistent instruments, to enable results to be compared, contrasted, and combined as appropriate. This systematic review describes the outcomes reported in clinical trials of pneumonia management and the instruments used to measure these outcomes. STUDY DESIGN AND SETTING: Based on a prospective protocol, we searched MEDLINE/PubMed, Cochrane CENTRAL and clinical trial registries for ongoing or completed clinical trials evaluating pneumonia management in adults in any clinical setting. We grouped reported outcomes thematically and classified them following the COMET Initiative's taxonomy. We describe instruments used for assessing each outcome. RESULTS: We found 280 eligible RCTs of which 115 (41.1%) enrolled critically ill patients and 165 (58.9%) predominantly noncritically ill patients. We identified 43 distinct outcomes and 108 measurement instruments, excluding nonvalidated scores and questionnaires. Almost all trials reported clinical/physiological outcomes (97.5%). Safety (63.2%), mortality (56.4%), resource use (48.6%) and life impact (11.8%) outcomes were less frequently addressed. The most frequently reported outcomes were treatment success (60.7%), mortality (56.4%) and adverse events (41.1%). There was significant variation in the selection of measurement instruments, with approximately two-thirds used in less than 10 of the 280 RCTs. None of the patient-reported outcomes were used in 10 or more RCTs. CONCLUSION: This review reveals significant variation in outcomes and measurement instruments reported in clinical trials of pneumonia management. Outcomes that are important to patients and health professionals are often omitted. Our findings support the need for a rigorous core outcome set, such as that being developed by the European Respiratory Society.

Cost-effectiveness of therapeutics for COVID-19 patients: a rapid review and economic analysis.

Background: Severe acute respiratory syndrome coronavirus 2 is the virus that causes coronavirus disease 2019. Over six million deaths worldwide have been associated with coronavirus disease 2019. Objective: To assess the cost-effectiveness of treatments used for the treatment of coronavirus disease 2019 in hospital or used in the community in patients with coronavirus disease 2019 at high risk of hospitalisation. Setting: Treatments provided in United Kingdom hospital and community settings. Methods: Clinical effectiveness estimates were taken from the coronavirus disease-network meta-analyses initiative and the metaEvidence initiative. A mathematical model was constructed to explore how the interventions impacted on patient health, measured in quality-adjusted life-years gained. The costs associated with treatment, including those of hospital care, were also estimated and used to form a cost per quality-adjusted life-year gained value which was compared with thresholds published by the National Institute for Health and Care Excellence. Estimates of cost-effectiveness compared against current standard of care were produced in both the hospital and community settings at three different levels of efficacy: mean, low and high. Public list prices were used for interventions with neither confidential patient access schemes nor confidential list prices considered. Results incorporating confidential pricing data were provided to the National Institute for Health and Care Excellence appraisal committee. Results: The treatments were estimated to be clinically effective although not all reached statistical significance. All treatments in the hospital setting, or community, were estimated to plausibly have a cost per quality-adjusted life-year gained value below National Institute for Health and Care Excellence's thresholds when compared with standard of care. However, almost all drugs could plausibly have cost per quality-adjusted life-years above National Institute for Health and Care Excellence's thresholds. However, there is considerable uncertainty in the results as the prevalent severe acute respiratory syndrome coronavirus 2 variant, vaccination status, history of being infected with severe acute respiratory syndrome coronavirus 2 and standard of care have all evolved since the pivotal studies were conducted which could have significant impact on the efficacy of each drug. For drugs used in high-risk patients in the community setting, the proportion of people at high risk who need hospital admission was a large driver of the cost per quality-adjusted life-year. Limitations: No studies were identified that were conducted in current conditions. This may be a large limitation as the severe acute respiratory syndrome coronavirus 2 variant changes. No head-to-head studies of interventions were identified. Conclusions: The results produced could be informative to decision-makers, although conclusions regarding the most clinical - and cost-effectiveness of each intervention should be tentative due to the evolving nature of the decision problem and, in this report, the use of list prices only. Comparisons between interventions should also be treated with caution due to potentially large heterogeneity between studies. Future work: Research assessing the relative clinical effectiveness of interventions within head-to-head studies in current conditions would be beneficial. Contemporary information related to the probability of hospital admission and death for patients at high risk in the community would improve the precision of the estimates generated. Funding: This project was funded by the National Institute for Health and Care Research (NIHR) Evidence Synthesis programme (NIHR135564) and will be published in full in Health Technology Assessment; Vol. 27, No. 14. See the NIHR Journals Library website for further project information.

Coronavirus disease 2019 is an infectious disease that can cause death and long-term ill-health. Treatments exist that can be provided in hospital to reduce the number of deaths from coronavirus disease 2019. Treatments also exist which can be provided in the community for people at high risk of needing to be admitted to hospital to reduce the number of admissions and to reduce the number of deaths from coronavirus disease 2019. However, the value for money of these treatments has not been estimated. We took the clinical effectiveness of nine treatments from published literature sources and built a model that estimated the value for money of six treatments compared with care without these treatments. Three treatments were excluded due to confidential prices. The results of the model showed that many treatments in a hospital setting had estimates of cost-effectiveness that would normally be seen to be good value for money using the thresholds published by the National Institute of Health and Care Excellence. The same was true for some treatments in a community setting. However, it is also possible that these treatments are not good value for money. The benefit of the drugs and value for money is highly uncertain as studies trying to estimate the gain have been done with (1) previous variants of the virus causing coronavirus disease 2019 being widespread, (2) where the proportion of people who have had vaccinations or who had previously had coronavirus disease 2019 is low and (3) where standard treatment was that when coronavirus disease 2019 was first identified, and not the drugs used now. Because of these differences, and the unknown price of some interventions, we cannot confidently say which (if any) treatments help patients the most, or which treatment represents the best value for money. Further research, in current conditions, would improve the accuracy of our answers.

biomArker-guided Duration of Antibiotic treatment in hospitalised Patients with suspecTed Sepsis (ADAPT-Sepsis): A protocol for a multicentre randomised controlled trial.

Aim: To describe the protocol for a multi-centre randomised controlled trial to determine whether treatment protocols monitoring daily CRP (C-reactive protein) or PCT (procalcitonin) safely allow a reduction in duration of antibiotic therapy in hospitalised adult patients with sepsis. Design: Multicentre three-arm randomised controlled trial. Setting: UK NHS hospitals. Target population: Hospitalised critically ill adults who have been commenced on intravenous antibiotics for sepsis. Health technology: Three protocols for guiding antibiotic discontinuation will be compared: (a) standard care; (b) standard care + daily CRP monitoring; (c) standard care + daily PCT monitoring. Standard care will be based on routine sepsis management and antibiotic stewardship. Measurement of outcomes and costs. Outcomes will be assessed to 28 days. The primary outcomes are total duration of antibiotics and safety outcome of all-cause mortality. Secondary outcomes include: escalation of care/re-admission; infection re-lapse/recurrence; antibiotic dose; length and level of critical care stay and length of hospital stay. Ninety-day all-cause mortality rates will also be collected. An assessment of cost effectiveness will be performed. Conclusion: In the setting of routine NHS care, if this trial finds that a treatment protocol based on monitoring CRP or PCT safely allows a reduction in duration of antibiotic therapy, and is cost effective, then this has the potential to change clinical practice for critically ill patients with sepsis. Moreover, if a biomarker-guided protocol is not found to be effective, then it will be important to avoid its use in sepsis and prevent ineffective technology becoming widely adopted in clinical practice.

Healthcare resilience: a meta-narrative systematic review and synthesis of reviews.

OBJECTIVES: The COVID-19 pandemic has tested global healthcare resilience. Many countries previously considered 'resilient' have performed poorly. Available organisational and system frameworks tend to be context-dependent and focus heavily on physical capacities. This study aims to explore and synthesise evidence about healthcare resilience and present a unified framework for future resilience-building. DESIGN: Systematic review and synthesis of reviews using a meta-narrative approach. SETTING: Healthcare organisations and systems. PRIMARY AND SECONDARY OUTCOME MEASURES: Definitions, concepts and measures of healthcare resilience. We used thematic analysis across included reviews to summarise evidence on healthcare resilience. RESULTS: The main paradigms within healthcare resilience include global health, disaster risk reduction, emergency management, patient safety and public health. Definitions of healthcare resilience recognise various hierarchical levels: individual (micro), facility or organisation (meso), health system (macro) and planetary or international (meta). There has been a shift from a focus on mainly disasters and crises, to an 'all-hazards' approach to resilience. Attempts to measure resilience have met with limited success. We analysed key concepts to build a framework for healthcare resilience containing pre-event, intra-event, post-event and trans-event domains. Alongside, we synthesise a definition which dovetails with our framework. CONCLUSION: Resilience increasingly takes an all-hazards approach and a process-oriented perspective. There is increasing recognition of the relational aspects of resilience. Few frameworks incorporate these, and they are difficult to capture within measurement systems. We need to understand how resilience works across hierarchical levels, and how competing priorities may affect overall resilience. Understanding these will underpin interdisciplinary, cross-sectoral and multi-level approaches to healthcare resilience for the future. PROSPERO REGISTRATION NUMBER: CRD42022314729.

Use of hospital services by patients with chronic conditions in sub-Saharan Africa: a systematic review and meta-analysis.

Objective: To estimate the prevalence of individual chronic conditions and multimorbidity among adults admitted to hospital in countries in sub-Saharan Africa. Methods: We systematically searched MEDLINE®, Embase®, Global Index Medicus, Global Health and SciELO for publications reporting on patient cohorts recruited between 1 January 2010 and 12 May 2023. We included articles reporting prevalence of pre-specified chronic diseases within unselected acute care services (emergency departments or medical inpatient settings). No language restrictions were applied. We generated prevalence estimates using random-effects meta-analysis alongside 95% confidence intervals, 95% prediction intervals and I2 statistics for heterogeneity. To explore associations with age, sex, country-level income status, geographical region and risk of bias, we conducted pre-specified meta-regression, sub-group and sensitivity analyses. Findings: Of 6976 identified studies, 61 met the inclusion criteria, comprising data from 20 countries and 376 676 people. None directly reported multimorbidity, but instead reported prevalence for individual conditions. Among medical admissions, the highest prevalence was human immunodeficiency virus infection (36.4%; 95% CI: 31.3-41.8); hypertension (24.4%; 95% CI: 16.7-34.2); diabetes (11.9%; 95% CI: 9.9-14.3); heart failure (8.2%; 95% CI: 5.6-11.9); chronic kidney disease (7.7%; 95% CI: 3.9-14.7); and stroke (6.8%; 95% CI: 4.7-9.6). Conclusion: Among patients seeking hospital care in sub-Saharan Africa, multimorbidity remains poorly described despite high burdens of individual chronic diseases. Prospective public health studies of multimorbidity burden are needed to generate integrated and context-specific health system interventions that act to maximize patient survival and well-being.

A health systems approach to critical care delivery in low-resource settings: a narrative review.

There is a high burden of critical illness in low-income countries (LICs), adding pressure to already strained health systems. Over the next decade, the need for critical care is expected to grow due to ageing populations with increasing medical complexity; limited access to primary care; climate change; natural disasters; and conflict. In 2019, the 72nd World Health Assembly emphasised that an essential part of universal health coverage is improved access to effective emergency and critical care and to "ensure the timely and effective delivery of life-saving health care services to those in need". In this narrative review, we examine critical care capacity building in LICs from a health systems perspective. We conducted a systematic literature search, using the World Heath Organisation (WHO) health systems framework to structure findings within six core components or "building blocks": (1) service delivery; (2) health workforce; (3) health information systems; (4) access to essential medicines and equipment; (5) financing; and (6) leadership and governance. We provide recommendations using this framework, derived from the literature identified in our review. These recommendations are useful for policy makers, health service researchers and healthcare workers to inform critical care capacity building in low-resource settings.

The estimation of glomerular filtration in acute and critical illness: Challenges and opportunities.

Recent events have made it apparent that the creatinine based estimating equations for glomerular filtration have their flaws. Some flaws have been known for some time; others have prompted radical modification of the equations themselves. These issues persist in part owing to the behaviour of the creatinine molecule itself, particularly in acute and critical illness. There are significant implications for patient treatment decisions, including drug and fluid therapies and choice of imaging modality (contrast vs. non-contrast CT scan for example). An alternative biomarker, Cystatin C, has been used with some success both alone and in combination with creatinine to help improve the accuracy of particular estimating equations. Problems remain in certain circumstances and costs may limit the more widespread use of the alternative assay. This review will explore both the historical and more recent evidence for glomerular filtration estimation, including options to directly measure glomerular filtration (rather than estimate), perhaps the holy grail for both Biochemistry and Nephrology.

Monocyte migration profiles define disease severity in acute COVID-19 and unique features of long COVID.

BACKGROUND: COVID-19 is associated with a dysregulated immune response but it is unclear how immune dysfunction contributes to the chronic morbidity persisting in many COVID-19 patients during convalescence (long COVID). METHODS: We assessed phenotypical and functional changes of monocytes in COVID-19 patients during hospitalisation and up to 9 months of convalescence following COVID-19, respiratory syncytial virus or influenza A. Patients with progressive fibrosing interstitial lung disease were included as a positive control for severe, ongoing lung injury. RESULTS: Monocyte alterations in acute COVID-19 patients included aberrant expression of leukocyte migration molecules, continuing into convalescence (n=142) and corresponding with specific symptoms of long COVID. Long COVID patients with unresolved lung injury, indicated by sustained shortness of breath and abnormal chest radiology, were defined by high monocyte expression of C-X-C motif chemokine receptor 6 (CXCR6) (p<0.0001) and adhesion molecule P-selectin glycoprotein ligand 1 (p<0.01), alongside preferential migration of monocytes towards the CXCR6 ligand C-X-C motif chemokine ligand 16 (CXCL16) (p<0.05), which is abundantly expressed in the lung. Monocyte CXCR6 and lung CXCL16 were heightened in patients with progressive fibrosing interstitial lung disease (p<0.001), confirming a role for the CXCR6-CXCL16 axis in ongoing lung injury. Conversely, monocytes from long COVID patients with ongoing fatigue exhibited a sustained reduction of the prostaglandin-generating enzyme cyclooxygenase 2 (p<0.01) and CXCR2 expression (p<0.05). These monocyte changes were not present in respiratory syncytial virus or influenza A convalescence. CONCLUSIONS: Our data define unique monocyte signatures that define subgroups of long COVID patients, indicating a key role for monocyte migration in COVID-19 pathophysiology. Targeting these pathways may provide novel therapeutic opportunities in COVID-19 patients with persistent morbidity.

Antibacterial effects in blood irradiated with a polychromatic device mediated through reactive oxygen species: possible involvement of haem.

The antibacterial effects of a polychromatic light device designed for intravenous application were assessed in vitro. Staphylococcus aureus, Klebsiella pneumoniae, or Escherichia coli were exposed to a 60-min sequential light cycle comprising 365, 530, and 630 nm wavelengths in circulated sheep blood. Bacteria were quantified by viable counting. The potential involvement of reactive oxygen species in the antibacterial effect was assessed using the antioxidant N-acetylcysteine-amide. A modified device was then used to determine the effects of the individual wavelengths. Exposure of blood to the standard wavelength sequence caused small (c. 0.5 Log 10 CFU) but statistically significant reductions in viable counts for all three bacteria, which were prevented by the addition of N-acetylcysteine-amide. Bacterial inactivation did not occur in blood-free medium, but supplementation with haem restored the moderate bactericidal effect. In single-wavelength experiments, bacterial inactivation occurred only with red (630 nm) light. Concentrations of reactive oxygen species were significantly higher under light stimulation than in unstimulated controls. In summary, exposure of bacteria within blood to a cycle of visible light wavelengths resulted in small but statistically significant bacterial inactivation apparently mediated by a 630 nm wavelength only, via reactive oxygen species possibly generated by excitation of haem groups.

The association between time of in hospital cardiac arrest and mortality; a retrospective analysis of two UK databases.

AIMS: The incidence of in hospital cardiac arrest (IHCA) varies throughout the day. This study aimed to report the variation in incidence of IHCA, presenting rhythm and outcome based on the hour in which IHCA occurred. METHODS: We conducted a retrospective analysis of the National Cardiac Arrest Audit (NCAA) including patients who suffered an IHCA from 1st April 2011 to 31st December 2019. We then linked the NCAA and intensive care Case Mix Programme databases to explore the effect of time of IHCA on hospital survival in the subgroup of patients admitted to intensive care following IHCA. RESULTS: We identified 115,690 eligible patients in the NCAA database. Pulseless electrical activity was the commonest presenting rhythm (54.8%). 66,885 patients died in the immediate post resuscitation period. Overall, hospital survival in the NCAA cohort was 21.3%. We identified 13,858 patients with linked ICU admissions in the Case Mix Programme database; 37.0% survived to hospital discharge. The incidence of IHCA peaked at 06.00. Rates of return of spontaneous circulation, survival to hospital discharge and good neurological outcome were lowest between 05.00 and 07.00. Among those admitted to ICU, no clear diurnal variation in hospital survival was seen in the unadjusted or adjusted analysis. This pattern was consistent across all presenting rhythms. CONCLUSIONS: We observed higher rates of IHCA, and poorer outcomes at night. However, in those admitted to ICU, this variation was absent. This suggests patient factors and processes of care issues contribute to the variation in IHCA seen throughout the day.

Microbial Volatiles as Diagnostic Biomarkers of Bacterial Lung Infection in Mechanically Ventilated Patients.

BACKGROUND: Early and accurate recognition of respiratory pathogens is crucial to prevent increased risk of mortality in critically ill patients. Microbial-derived volatile organic compounds (mVOCs) in exhaled breath could be used as noninvasive biomarkers of infection to support clinical diagnosis. METHODS: In this study, we investigated the diagnostic potential of in vitro-confirmed mVOCs in the exhaled breath of patients under mechanical ventilation from the BreathDx study. Samples were analyzed by thermal desorption-gas chromatography-mass spectrometry. RESULTS: Pathogens from bronchoalveolar lavage (BAL) cultures were identified in 45 of 89 patients and Staphylococcus aureus was the most commonly identified pathogen (n = 15). Of 19 mVOCs detected in the in vitro culture headspace of 4 common respiratory pathogens (S. aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli), 14 were found in exhaled breath samples. Higher concentrations of 2 mVOCs were found in the exhaled breath of patients infected with S. aureus compared to those without (3-methylbutanal: P < .01, area under the receiver operating characteristic curve [AUROC] = 0.81-0.87; and 3-methylbutanoic acid: P = .01, AUROC = 0.79-0.80). In addition, bacteria identified from BAL cultures that are known to metabolize tryptophan (E. coli, Klebsiella oxytoca, and Haemophilus influenzae) were grouped and found to produce higher concentrations of indole compared to breath samples with culture-negative (P = .034) and other pathogen-positive (P = .049) samples. CONCLUSIONS: This study demonstrates the capability of using mVOCs to detect the presence of specific pathogen groups with potential to support clinical diagnosis. Although not all mVOCs were found in patient samples within this small pilot study, further targeted and qualitative investigation is warranted using multicenter clinical studies.

ClinCirc identifies alterations of the circadian peripheral oscillator in critical care patients.

BackgroundAssessing circadian rhythmicity from infrequently sampled data is challenging; however, these types of data are often encountered when measuring circadian transcripts in hospitalized patients.MethodsWe present ClinCirc. This method combines 2 existing mathematical methods (Lomb-Scargle periodogram and cosinor) sequentially and is designed to measure circadian oscillations from infrequently sampled clinical data. The accuracy of this method was compared against 9 other methods using simulated and frequently sampled biological data. ClinCirc was then evaluated in 13 intensive care unit (ICU) patients as well as in a separate cohort of 29 kidney-transplant recipients. Finally, the consequences of circadian alterations were investigated in a retrospective cohort of 726 kidney-transplant recipients.ResultsClinCirc had comparable performance to existing methods for analyzing simulated data or clock transcript expression of healthy volunteers. It had improved accuracy compared with the cosinor method in evaluating circadian parameters in PER2:luc cell lines. In ICU patients, it was the only method investigated to suggest that loss of circadian oscillations in the peripheral oscillator was associated with inflammation, a feature widely reported in animal models. Additionally, ClinCirc was able to detect other circadian alterations, including a phase shift following kidney transplantation that was associated with the administration of glucocorticoids. This phase shift could explain why a significant complication of kidney transplantation (delayed graft dysfunction) oscillates according to the time of day kidney transplantation is performed.ConclusionClinCirc analysis of the peripheral oscillator reveals important clinical associations in hospitalized patients.FundingUK Research and Innovation (UKRI), National Institute of Health Research (NIHR), Engineering and Physical Sciences Research Council (EPSRC), National Institute on Academic Anaesthesia (NIAA), Asthma+Lung UK, Kidneys for Life.

Clinical and health inequality risk factors for non-COVID-related sepsis during the global COVID-19 pandemic: a national case-control and cohort study.

Background: Sepsis, characterised by significant morbidity and mortality, is intricately linked to socioeconomic disparities and pre-admission clinical histories. This study aspires to elucidate the association between non-COVID-19 related sepsis and health inequality risk factors amidst the pandemic in England, with a secondary focus on their association with 30-day sepsis mortality. Methods: With the approval of NHS England, we harnessed the OpenSAFELY platform to execute a cohort study and a 1:6 matched case-control study. A sepsis diagnosis was identified from the incident hospital admissions record using ICD-10 codes. This encompassed 248,767 cases with non-COVID-19 sepsis from a cohort of 22.0 million individuals spanning January 1, 2019, to June 31, 2022. Socioeconomic deprivation was gauged using the Index of Multiple Deprivation score, reflecting indicators like income, employment, and education. Hospitalisation-related sepsis diagnoses were categorised as community-acquired or hospital-acquired. Cases were matched to controls who had no recorded diagnosis of sepsis, based on age (stepwise), sex, and calendar month. The eligibility criteria for controls were established primarily on the absence of a recorded sepsis diagnosis. Associations between potential predictors and odds of developing non-COVID-19 sepsis underwent assessment through conditional logistic regression models, with multivariable regression determining odds ratios (ORs) for 30-day mortality. Findings: The study included 224,361 (10.2%) cases with non-COVID-19 sepsis and 1,346,166 matched controls. The most socioeconomic deprived quintile was associated with higher odds of developing non-COVID-19 sepsis than the least deprived quintile (crude OR 1.80 [95% CI 1.77-1.83]). Other risk factors (after adjusting comorbidities) such as learning disability (adjusted OR 3.53 [3.35-3.73]), chronic liver disease (adjusted OR 3.08 [2.97-3.19]), chronic kidney disease (stage 4: adjusted OR 2.62 [2.55-2.70], stage 5: adjusted OR 6.23 [5.81-6.69]), cancer, neurological disease, immunosuppressive conditions were also associated with developing non-COVID-19 sepsis. The incidence rate of non-COVID-19 sepsis decreased during the COVID-19 pandemic and rebounded to pre-pandemic levels (April 2021) after national lockdowns had been lifted. The 30-day mortality risk in cases with non-COVID-19 sepsis was higher for the most deprived quintile across all periods. Interpretation: Socioeconomic deprivation, comorbidity and learning disabilities were associated with an increased odds of developing non-COVID-19 related sepsis and 30-day mortality in England. This study highlights the need to improve the prevention of sepsis, including more precise targeting of antimicrobials to higher-risk patients. Funding: The UK Health Security Agency, Health Data Research UK, and National Institute for Health Research.

Procalcitonin Evaluation of Antibiotic Use in COVID-19 Hospitalised Patients (PEACH): Protocol for a Retrospective Observational Study.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel virus responsible for the coronavirus disease 2019 (COVID-19) pandemic. Although COVID-19 is a viral illness, many patients admitted to hospital are prescribed antibiotics, based on concerns that COVID-19 patients may experience secondary bacterial infections, and the assumption that they may respond well to antibiotic therapy. This has led to an increase in antibiotic use for some hospitalised patients at a time when accumulating antibiotic resistance is a major global threat to health. Procalcitonin (PCT) is an inflammatory marker measured in blood samples and widely recommended to help diagnose bacterial infections and guide antibiotic treatment. The PEACH study will compare patient outcomes from English and Welsh hospitals that used PCT testing during the first wave of the COVID-19 pandemic with those from hospitals not using PCT. It will help to determine whether, and how, PCT testing should be used in the NHS in future waves of COVID-19 to protect patients from antibiotic overuse. PEACH is a retrospective observational cohort study using patient-level clinical data from acute hospital Trusts and Health Boards in England and Wales. The primary objective is to measure the difference in antibiotic use between COVID-19 patients who did or did not have PCT testing at the time of diagnosis. Secondary objectives include measuring differences in length of stay, mortality, intensive care unit admission, and resistant bacterial infections between these groups.

The accuracy of pulse oximetry in measuring oxygen saturation by levels of skin pigmentation: a systematic review and meta-analysis.

BACKGROUND: During the COVID-19 pandemic, there have been concerns regarding potential bias in pulse oximetry measurements for people with high levels of skin pigmentation. We systematically reviewed the effects of skin pigmentation on the accuracy of oxygen saturation measurement by pulse oximetry (SpO2) compared with the gold standard SaO2 measured by CO-oximetry. METHODS: We searched Ovid MEDLINE, Ovid Embase, EBSCO CINAHL, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform (up to December 2021) for studies with SpO2-SaO2 comparisons and measuring the impact of skin pigmentation or ethnicity on pulse oximetry accuracy. We performed meta-analyses for mean bias (the primary outcome in this review) and its standard deviations (SDs) across studies included for each subgroup of skin pigmentation and ethnicity and used these pooled mean biases and SDs to calculate accuracy root-mean-square (Arms) and 95% limits of agreement. The review was registered with the Open Science Framework ( https://osf.io/gm7ty ). RESULTS: We included 32 studies (6505 participants): 15 measured skin pigmentation and 22 referred to ethnicity. Compared with standard SaO2 measurement, pulse oximetry probably overestimates oxygen saturation in people with the high level of skin pigmentation (pooled mean bias 1.11%; 95% confidence interval 0.29 to 1.93%) and people described as Black/African American (1.52%; 0.95 to 2.09%) (moderate- and low-certainty evidence). The bias of pulse oximetry measurements for people with other levels of skin pigmentation or those from other ethnic groups is either more uncertain or suggests no overestimation. Whilst the extent of mean bias is small or negligible for all subgroups evaluated, the associated imprecision is unacceptably large (pooled SDs > 1%). When the extent of measurement bias and precision is considered jointly, pulse oximetry measurements for all the subgroups appear acceptably accurate (with Arms < 4%). CONCLUSIONS: Pulse oximetry may overestimate oxygen saturation in people with high levels of skin pigmentation and people whose ethnicity is reported as Black/African American, compared with SaO2. The extent of overestimation may be small in hospital settings but unknown in community settings. REVIEW PROTOCOL REGISTRATION: https://osf.io/gm7ty.