Time to first antibiotic and mortality in adults hospitalised with community-acquired pneumonia: a matched-propensity analysis

The potential of virtual triage AI to improve early detection, care acuity alignment, and emergent care referral of life-threatening conditions

Objective

To evaluate the extent to which patient-users reporting symptoms of five severe/acute conditions requiring emergency care to an AI-based virtual triage (VT) engine had no intention to get such care, and whose acuity perception was misaligned or decoupled from actual risk of life-threatening symptoms.

Methods

A dataset of 3,022,882 VT interviews conducted over 16 months was evaluated to quantify and describe patient-users reporting symptoms of five potentially life-threatening conditions whose pre-triage healthcare intention was other than seeking urgent care, including myocardial infarction, stroke, asthma exacerbation, pneumonia, and pulmonary embolism.

Results

Healthcare intent data was obtained for 12,101 VT patient-user interviews. Across all five conditions a weighted mean of 38.5% of individuals whose VT indicated a condition requiring emergency care had no pre-triage intent to consult a physician. Furthermore, 61.5% intending to possibly consult a physician had no intent to seek emergency medical care. After adjustment for 13% VT safety over-triage/referral to ED, a weighted mean of 33.5% of patient-users had no intent to seek professional care, and 53.5% had no intent to seek emergency care.

Conclusion

AI-based VT may offer a vehicle for early detection and care acuity alignment of severe evolving pathology by engaging patients who believe their symptoms are not serious, and for accelerating care referral and delivery for life-threatening conditions where patient misunderstanding of risk, or indecision, causes care delay. A next step will be clinical confirmation that when decoupling of patient care intent from emergent care need occurs, VT can influence patient behavior to accelerate care engagement and/or emergency care dispatch and treatment to improve clinical outcomes.

Severe Community-Acquired Pneumonia in Immunocompromised Patients

Due to higher survival rates with good quality of life, related to new treatments in the fields of oncology, hematology, and transplantation, the number of immunocompromised patients is increasing. But these patients are at high risk of intensive care unit admission because of numerous complications. Acute respiratory failure due to severe community-acquired pneumonia is one of the leading causes of admission. In this setting, the need for invasive mechanical ventilation is up to 60%, associated with a high hospital mortality rate of around 40 to 50%. A wide range of pathogens according to the reason of immunosuppression is associated with severe pneumonia in those patients: documented bacterial pneumonia represents a third of cases, viral and fungal pneumonia both account for up to 15% of cases. For patients with an undetermined etiology despite comprehensive diagnostic workup, the hospital mortality rate is very high. Thus, a standardized diagnosis strategy should be defined to increase the diagnosis rate and prescribe the appropriate treatment. This review focuses on the benefit-to-risk ratio of invasive or noninvasive strategies, in the era of omics, for the management of critically ill immunocompromised patients with severe pneumonia in terms of diagnosis and oxygenation.

Quantifying the Economic and Clinical Value of Reducing Antimicrobial Resistance in Gram-negative Pathogens Causing Hospital-Acquired Infections in Australia

INTRODUCTION

Antimicrobial resistance (AMR) is a global public health challenge requiring a global response to which Australia has issued a National Antimicrobial Resistance Strategy. The necessity for continued-development of new effective antimicrobials is required to tackle this immediate health threat is clear, but current market conditions may undervalue antimicrobials. We aimed to estimate the health-economic benefits of reducing AMR levels for drug-resistant gram-negative pathogens in Australia, to inform health policy decision-making.

METHODS

A published and validated-dynamic health economic model was adapted to the Australian setting. Over a 10-year time horizon, the model estimates the clinical and economic outcomes associated with reducing current AMR levels, by up to 95%, of three gram-negative pathogens in three hospital-acquired infections, from the perspective of healthcare payers. A willingness-to-pay threshold of AUD$15,000-$45,000 per quality-adjusted life-year (QALY) gained and a 5% discount rate (for costs and benefits) were applied.

RESULTS

Over ten years, reducing AMR for gram-negative pathogens in Australia is associated with up to 10,251 life-years and 8924 QALYs gained, 9041 bed-days saved and 6644 defined-daily doses of antibiotics avoided. The resulting savings are estimated to be $10.5 million in hospitalisation costs, and the monetary benefit at up to $412.1 million.

DISCUSSION

Our results demonstrate the clinical and economic value of reducing AMR impact in Australia. Of note, since our analysis only considered a limited number of pathogens in the hospital setting only and for a limited number of infection types, the benefits of counteracting AMR are likely to extend well beyond the ones demonstrated here.

CONCLUSION

These estimates demonstrate the consequences of failure to combat AMR in the Australian context. The benefits in mortality and health system costs justify consideration of innovative reimbursement schemes to encourage the development and commercialisation of new effective antimicrobials.

Rapid treatment of endophthalmitis with intravitreal antibiotics is associated with better vision outcomes

BACKGROUND

To discover whether the timing of intravitreal antibiotics, from the time of presentation to injection, affects the visual outcomes of patients with endophthalmitis from all causes.

METHODS

A retrospective study of consecutive patients managed at Auckland District Health Board between 1 January 2004 and 1 July 2021. The main outcome measure was final visual acuity at follow-up and the proportion of subjects with severe vision loss (≤6/60).

RESULTS

Three hundred and seventy-four eyes were included in the study, with a median age of 69.7 years at presentation; 192 subjects (51.6%) were female. The median presenting visual acuity was hand movements and hypopyon was present in 194 subjects (51.9%). Cataract surgery was the most frequent aetiology in 115 subjects (30.7%), followed by intravitreal anti-vascular endothelial growth factor injections in 89 subjects (23.8%) and endogenous endophthalmitis in 54 subjects (14.4%). Median time to injection of intravitreal antibiotics was 3.5 h (Interquartile range 2-6). On multivariate analysis, early treatment with intravitreal antibiotics was associated with better visual outcome, particularly for those treated within 2 h, while poor presenting visual acuity and culture-positive endophthalmitis were associated with worse outcomes.

CONCLUSION

Rapid intravitreal antibiotic administration is associated with better final visual acuity outcomes, particularly for those receiving treatment within 2 h of presentation. Patients with severe vision loss on presentation, benefit the most with improved final visual acuity following expedited treatment.

Molecular point-of-care testing for lower respiratory tract pathogens improves safe antibiotic de-escalation in patients with pneumonia in the ICU: results of a randomised controlled trial

BACKGROUND

Effective treatment of pneumonia requires timely administration of appropriate antimicrobials but standard diagnostic tests take around 48 hours to generate results. Highly accurate, rapid molecular tests have been developed for identifying organisms in lower respiratory tract samples, however their impact on antibiotic use is unknown. The aim of this study was to assess the impact of syndromic molecular point-of-care testing compared to conventional diagnostic testing, on antibiotic use.

METHODS

In this pragmatic, randomised controlled trial, we enrolled critically ill adults with pneumonia. Patients were assigned (1:1) to molecular testing of samples at the point-of-care or routine clinical care. The primary outcome was the proportion of patients who received results-directed antimicrobial therapy.

RESULTS

200 patients were randomly assigned to point-of-care testing (n=100) or the control group (n=100). 85 patients had community acquired pneumonia (42 in the mPOCT group and 43 in the control group), 69 hospital acquired pneumonia (30 in mPOCT and 39 in control) and 46 ventilator associated pneumonia (28 in mPOCT and 18 in control). The median [IQR] time to results was 1.7 [1.6-1.9] hours for point-of-care testing and 66.7 [56.7-88.5] hours for standard diagnostics (difference of -65.0 hours, 95%CI -68.0 to -62.0; p<0.0001). 71 (71%) patients in the point-of-care testing arm had pathogens detected compared to 51 (51%) in the control arm (difference of 20%, 95%CI 7 to 33; p=0.004). 80 (80%) of patients in the point-of-care group received results-directed therapy, compared with 29 (29%) of 99 in the control group (difference of 51%, 95%CI 39-63; p<0.0001). Time to results-directed therapy was 2.3 [1.8-7.2] hours in the mPOCT group and 46.1 [23.0-51.5] hours in the control group (difference of -43.8 hours, 95% CI -48.9 to -38.6; p<0.0001). 42 (42%) patients in mPOCT group had antibiotics de-escalated compared with 8 (8%) of 98 in the control group (difference of 34%, 95%CI 23-45; p<0.0001). Time to de-escalation was 4.8 [2.4-13.0] hours in the mPOCT group compared with 46.5 [26.3-48.6] hours in the control group (difference of -41.4 hours, 95%CI -53 to -29.7; p<0.0001). There was no major difference in antibiotic duration or in clinical or safety outcomes between the two groups.

CONCLUSIONS

Use of molecular point-of-care testing in patients with pneumonia returned results more rapidly and identified more pathogens than conventional testing. This was associated with improvements in appropriate antimicrobial use and appeared safe.

Diagnostic Accuracy of Procalcitonin upon Emergency Department Admission during SARS-CoV-2 Pandemic

INTRODUCTION

Procalcitonin is a marker for bacterial diseases and has been used to guide antibiotic prescription. Procalcitonin accuracy, measured at admission, in patients with community-acquired pneumonia (CAP), is unknown in the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic.

OBJECTIVES

To evaluate the diagnostic accuracy of procalcitonin to assess the need for antibiotic treatment in patients with CAP presenting to the emergency department during the SARS-CoV-2 pandemic.

METHODS

We performed a real-world diagnostic retrospective accuracy study of procalcitonin in patients admitted to the emergency department. Measures of diagnostic accuracy were calculated based on procalcitonin results compared to the reference standard of combined microbiological and radiological analysis. Sensitivity, specificity, positive and negative predictive values, and area under (AUC) the receiver-operating characteristic (ROC) curve were calculated in two analyses: first assessing procalcitonin ability to differentiate microbiologically proven bacteria from viral CAP and then clinically diagnosed bacterial CAP from viral CAP.

RESULTS

When using a procalcitonin threshold of 0.5 ng/mL to identify bacterial etiology within patients with CAP, we observed sensitivity and specificity of 50% and 64.1%, and 43% and 82.6%, respectively, in the two analyses. The positive and negative predictive values of a procalcitonin threshold of 0.5 ng/mL to identify patients for whom antibiotics should be advised were 46.4% and 79.7%, and 48.9% and 79% in the two analyses, respectively. The AUC for the two analyses was 0.60 (95% confidence interval [CI] 0.52-0.68) and 0.62 (95% CI, 0.55-0.69).

CONCLUSIONS

Procalcitonin measured upon admission during the SARS-CoV-2 pandemic should not guide antibiotic treatment in patients with CAP.

Pham S, P.M. Vo T, X. Duong C, A. Perwitasari D, H.K. Truong N, T.H. Quach D, N.P. Nguyen T, T.T. Duong V, M. Nguyen P, H. Nguyen T, Taxis K, Nguyen T. Pneumonia: Drug-Related Problems and Hospital Readmissions

Pneumonia is one of the most common infectious diseases and the fourth leading cause of death globally. According to US statistics in 2019, pneumonia is the most common cause of sepsis and septic shock. In the US, inpatient pneumonia hospitalizations account for the top 10 highest medical costs, totaling $9.5 billion for 960,000 hospital stays. The emergence of antibiotic resistance in the treatment of infectious diseases, including the treatment of pneumonia, is a globally alarming problem. Antibiotic resistance increases the risk of death and re-hospitalization, prolongs hospital stays, and increases treatment costs, and is one of the greatest threats in modern medicine. Drug-related problems (DRPs) in pneumonia - such as suboptimal antibiotic indications, prolonged treatment duration, and drug interactions - increase the rate of antibiotic resistance and adverse effects, thereby leading to an increased burden in treatment. In a context in which novel and effective antibiotics are scarce, mitigating DRPs in order to reduce antibiotic resistance is currently a prime concern. A variety of interventions proven useful in reducing DRPs are antibiotic stewardship programs, the use of biomarkers, computerized physician order entries and clinical decision support systems, and community-acquired pneumonia scores.

Predictive factors of six-week mortality in critically ill patients with SARS-CoV-2: A multicenter prospective study

Objective

The objective of the study is to identify the risk factors associated with mortality at six weeks, especially by analyzing the role of antivirals and munomodulators.

Design

Prospective descriptive multicenter cohort study.

Setting

26 Intensive care units (ICU) from Andalusian region in Spain.

Patients or participants

Consecutive critically ill patients with confirmed SARS-CoV-2 infection were included from March 8 to May 30.

Interventions

None.

Variables

Variables analyzed were demographic, severity scores and clinical condition. Support therapy, drug and mortality were analyzed. An univariate followed by multivariate Cox regression with propensity score analysis was applied.

Results

495 patients were enrolled, but 73 of them were excluded for incomplete data. Thus, 422 patients were included in the final analysis. Median age was 63 years and 305 (72.3%) were men. ICU mortality: 144/422 34%; 14 days mortality: 81/422 (19.2%); 28 days mortality: 121/422 (28.7%); 6-week mortality 152/422 36.5%. By multivariable Cox proportional analysis, factors independently associated with 42-day mortality were age, APACHE II score, SOFA score at ICU admission >6, Lactate dehydrogenase at ICU admission >470 U/L, Use of vasopressors, extrarenal depuration, %lymphocytes 72 h post-ICU admission <6.5%, and thrombocytopenia whereas the use of lopinavir/ritonavir was a protective factor.

Conclusion

Age, APACHE II, SOFA > value of 6 points, along with vasopressor requirements or renal replacement therapy have been identified as predictor factors of mortality at six weeks.

Administration of corticosteroids showed no benefits in mortality, as did treatment with tocilizumab.

Lopinavir/ritonavir administration is identified as a protective factor.

Association of ICU Admission and Outcomes in Sepsis and Acute Respiratory Failure

Rationale: Many decisions to admit patients to the ICU are not grounded in evidence regarding who benefits from such triage, straining ICU capacity and limiting its cost-effectiveness. Objectives: To measure the benefits of ICU admission for patients with sepsis or acute respiratory failure. Methods: At 27 United States hospitals across two health systems from 2013 to 2018, we performed a retrospective cohort study using two-stage instrumental variable quantile regression with a strong instrument (hospital capacity strain) governing ICU versus ward admission among high-acuity patients (i.e., laboratory-based acute physiology score v2 ⩾ 100) with sepsis and/or acute respiratory failure who did not require mechanical ventilation or vasopressors in the emergency department. Measurements and Main Results: Among patients with sepsis (n = 90,150), admission to the ICU was associated with a 1.32-day longer hospital length of stay (95% confidence interval [CI], 1.01-1.63; P < 0.001) (when treating deaths as equivalent to long lengths of stay) and higher in-hospital mortality (odds ratio, 1.48; 95% CI, 1.13-1.88; P = 0.004). Among patients with respiratory failure (n = 45,339), admission to the ICU was associated with a 0.82-day shorter hospital length of stay (95% CI, -1.17 to -0.46; P < 0.001) and reduced in-hospital mortality (odds ratio, 0.75; 95% CI, 0.57-0.96; P = 0.04). In sensitivity analyses of length of stay, excluding, ignoring, or censoring death, results were similar in sepsis but not in respiratory failure. In subgroup analyses, harms of ICU admission for patients with sepsis were concentrated among older patients and those with fewer comorbidities, and the benefits of ICU admission for patients with respiratory failure were concentrated among older patients, highest-acuity patients, and those with more comorbidities. Conclusions: Among high-acuity patients with sepsis who did not require life support in the emergency department, initial admission to the ward, compared with the ICU, was associated with shorter length of stay and improved survival, whereas among patients with acute respiratory failure, triage to the ICU compared with the ward was associated with improved survival.

Comparative characteristics of the background and blood test findings in adults with pneumococcal pneumonia and invasive pneumococcal disease: A retrospective study

INTRODUCTION

Invasive pneumococcal disease (IPD) is often fatal, requiring prompt diagnosis and treatment. To evaluate the factors associated with IPD in adults, we retrospectively investigated its characteristics compared to pneumococcal pneumonia without confirmation of invasion (PP).

METHODS

Patients >18 years with PP (n = 79) and IPD (n = 53) from whom Streptococcus pneumoniae was isolated were enrolled from two hospitals between 2011 and 2017. Clinical backgrounds, blood test results at admission, initial antimicrobials administered, isolate serotypes, and outcomes were compared between the PP and IPD groups.

RESULTS

Patients with IPD exhibited higher mortality (28.3%) than those with PP (2.5%) (p<0.001), regardless of the type of antimicrobials first administered. The majority (80.0%) of fatal cases of IPD were due to vaccine serotypes. Almost all patients with PP (97.4%) and IPD (88.7%) had underlying disease. C-reactive protein (CRP) ≥17.0 mg/dL (odds ratio [OR], 7.1; 95% CI, 2.7-19.0; p<0.001), white blood cell counts <11.0 × 10³/μL (OR, 3.2; 95% CI, 1.3-8.4; p = 0.016), and platelet (PLT) counts <16.2 × 10⁴/μL (OR, 2.8; 95% CI, 1.1-7.4; p = 0.036) were significantly more common in IPD. Moreover, 89.5% of cases with both CRP ≥23.8 mg/dL and PLT <18.5 × 10⁴/μL were diagnosed with IPD.

CONCLUSION

Laboratory blood test findings at admission, particularly high CRP and low PLT values, are useful early indicators of IPD in adults. These results could be used to initiate rapid and intensive treatment and improve prognosis.

Antibiotic prescription consistent with guidelines in emergency department is associated with 30-day survival in severe community-acquired pneumonia

BACKGROUND

The selection of initial empirical antibiotics is an important issue in the treatment of severe community-acquired pneumonia (CAP). This study aimed to investigate whether empirical antibiotic prescription concordant with guidelines in the emergency department (ED) affects 30-day mortality in patients with severe CAP.

METHODS

We conducted a retrospective analysis of adult patients with severe CAP who were hospitalized in the ED. Severe CAP was defined according to the criteria of the 2007 Infectious Diseases Society of America/American Thoracic Society guidelines. Patients were divided into two groups according to whether they were prescribed empirical antibiotics concordant with guidelines. Multivariable Cox proportional hazard regression analysis was performed to identify the independent association between the prescription of initial empirical antibiotics concordant with the guidelines and 30-day mortality. Propensity score matching was performed to reduce selection bias between groups and Kaplan-Meier survival analysis was performed to analyze the time-to-event of 30-day survival.

RESULTS

In total, 630 patients were hospitalized in the ED for severe CAP, and 179 (28.4%) died within 30 days. Antibiotics consistent with guidelines were prescribed to 359 (57.0%) patients. The 30-day mortality was significantly higher in the guideline-discordant group (p = 0.003) and multivariable Cox proportional hazard regression analysis revealed that the prescription of antibiotics discordant with the guidelines was independently associated with 30-day mortality (hazard ratio 1.43, 95% CI 1.05-1.93). After propensity score matching, there were 255 patients in each group. The 30-day mortality was lower in the group prescribed guideline-concordant antibiotics than in the group prescribed guideline-discordant antibiotics (23.9% vs. 33.3%, p = 0.024). Kaplan-Meier survival analysis showed that antibiotic prescription concordant with the guidelines resulted in higher survival rates at 30 days (p = 0.002).

CONCLUSIONS

The prevalence of antibiotic prescription consistent with guidelines for severe CAP seemed to be low in the ED, and this variable was independently associated with 30-day survival.

VB10, a new blood biomarker for differential diagnosis and recovery monitoring of acute viral and bacterial infections

BACKGROUND

Precise differential diagnosis between acute viral and bacterial infections is important to enable appropriate therapy, avoid unnecessary antibiotic prescriptions and optimize the use of hospital resources. A systems view of host response to infections provides opportunities for discovering sensitive and robust molecular diagnostics.

METHODS

We combine blood transcriptomes from six independent datasets (n = 756) with a knowledge-based human protein-protein interaction network, identifies subnetworks capturing host response to each infection class, and derives common response cores separately for viral and bacterial infections. We subject the subnetworks to a series of computational filters to identify a parsimonious gene panel and a standalone diagnostic score that can be applied to individual samples. We rigorously validate the panel and the diagnostic score in a wide range of publicly available datasets and in a newly developed Bangalore-Viral Bacterial (BL-VB) cohort.

FINDING

We discover a 10-gene blood-based biomarker panel (Panel-VB) that demonstrates high predictive performance to distinguish viral from bacterial infections, with a weighted mean AUROC of 0.97 (95% CI: 0.96-0.99) in eleven independent datasets (n = 898). We devise a new stand-alone patient-wise score (VB10) based on the panel, which shows high diagnostic accuracy with a weighted mean AUROC of 0.94 (95% CI 0.91-0.98) in 2996 patient samples from 56 public datasets from 19 different countries. Further, we evaluate VB10 in a newly generated South Indian (BL-VB, n = 56) cohort and find 97% accuracy in the confirmed cases of viral and bacterial infections. We find that VB10 is (a) capable of accurately identifying the infection class in culture-negative indeterminate cases, (b) reflects recovery status, and (c) is applicable across different age groups, covering a wide spectrum of acute bacterial and viral infections, including uncharacterized pathogens. We tested our VB10 score on publicly available COVID-19 data and find that our score detected viral infection in patient samples.

INTERPRETATION

Our results point to the promise of VB10 as a diagnostic test for precise diagnosis of acute infections and monitoring recovery status. We expect that it will provide clinical decision support for antibiotic prescriptions and thereby aid in antibiotic stewardship efforts.

FUNDING

Grand Challenges India, Biotechnology Industry Research Assistance Council (BIRAC), Department of Biotechnology, Govt. of India.

Inhibition of the lipoxin A4 and resolvin D1 receptor impairs host response to acute lung injury caused by pneumococcal pneumonia in mice

Resolution of the acute respiratory distress syndrome (ARDS) from pneumonia requires repair of the injured lung endothelium and alveolar epithelium, removal of neutrophils from the distal airspaces of the lung, and clearance of the pathogen. Previous studies have demonstrated the importance of specialized proresolving mediators (SPMs) in the regulation of host responses during inflammation. Although ARDS is commonly caused by Streptococcus pneumoniae, the role of lipoxin A4 (LXA4) and resolvin D1 (RvD1) in pneumococcal pneumonia is not well understood. In the present experimental study, we tested the hypothesis that endogenous SPMs play a role in the resolution of lung injury in a clinically relevant model of bacterial pneumonia. Blockade of formyl peptide receptor 2 (ALX/FPR2), the receptor for LXA4 and RvD1, with the peptide WRW4 resulted in more pulmonary edema, greater protein accumulation in the air spaces, and increased bacteria accumulation in the air spaces and the blood. Inhibition of this receptor was also associated with decreased levels of proinflammatory cytokines. Even in the presence of antibiotic treatment, WRW4 inhibited the resolution of lung injury. In summary, these experiments demonstrated two novel findings: LXA4 and RvD1 contribute to the resolution of lung injury due to pneumococcal pneumonia, and the mechanism of their benefit likely includes augmenting bacterial clearance and reducing pulmonary edema via the restoration of lung alveolar-capillary barrier permeability.

Predictive factors of six-week mortality in critically ill patients with SARS-CoV-2: A multicenter prospective study

OBJECTIVE

The objective of the study is to identify the risk factors associated with mortality at six weeks, especially by analyzing the role of antivirals and munomodulators.

DESIGN

Prospective descriptive multicenter cohort study.

SETTING

26 Intensive care units (ICU) from Andalusian region in Spain.

PATIENTS OR PARTICIPANTS

Consecutive critically ill patients with confirmed SARS-CoV-2 infection were included from March 8 to May 30.

INTERVENTIONS

None.

VARIABLES

Variables analyzed were demographic, severity scores and clinical condition. Support therapy, drug and mortality were analyzed. An univariate followed by multivariate Cox regression with propensity score analysis was applied.

RESULTS

495 patients were enrolled, but 73 of them were excluded for incomplete data. Thus, 422 patients were included in the final analysis. Median age was 63 years and 305 (72.3%) were men. ICU mortality: 144/422 34%; 14 days mortality: 81/422 (19.2%); 28 days mortality: 121/422 (28.7%); 6-week mortality 152/422 36.5%. By multivariable Cox proportional analysis, factors independently associated with 42-day mortality were age, APACHE II score, SOFA score at ICU admission >6, Lactate dehydrogenase at ICU admission >470U/L, Use of vasopressors, extrarenal depuration, %lymphocytes 72h post-ICU admission <6.5%, and thrombocytopenia whereas the use of lopinavir/ritonavir was a protective factor.

CONCLUSION

Age, APACHE II, SOFA>value of 6 points, along with vasopressor requirements or renal replacement therapy have been identified as predictor factors of mortality at six weeks. Administration of corticosteroids showed no benefits in mortality, as did treatment with tocilizumab. Lopinavir/ritonavir administration is identified as a protective factor.

Impact of time to antibiotic therapy on clinical outcome in patients with bacterial infections in the emergency department: implications for antimicrobial stewardship

BACKGROUND

Rapid initiation of antibiotic treatment is considered crucial in patients with severe infections such as septic shock and bacterial meningitis, but may not be as important for other infectious syndromes. A better understanding of which patients can tolerate a delay in start of therapy is important for antibiotic stewardship purposes.

OBJECTIVES

To explore the existing evidence on the impact of time to antibiotics on clinical outcomes in patients presenting to the emergency department (ED) with bacterial infections of different severity of illness and source of infection.

SOURCES

A literature search was performed in the PubMed/MEDLINE database using combined search terms for various infectious syndromes (sepsis/septic shock, bacterial meningitis, lower respiratory tract infections, urinary tract infections, intra-abdominal infections and skin and soft tissue infections), time to antibiotic treatment, and clinical outcome.

CONTENT

The literature search generated 8828 hits. After screening titles and abstracts and assessing potentially relevant full-text papers, 60 original articles (four randomized controlled trials, 43 observational studies) were included. Most articles addressed sepsis/septic shock, while few studies evaluated early initiation of therapy in mild to moderate disease. The lack of randomized trials and the risk of confounding factors and biases in observational studies warrant caution in the interpretation of results. We conclude that the literature supports prompt administration of effective antibiotics for septic shock and bacterial meningitis, but there is no clear evidence showing that a delayed start of therapy is associated with worse outcome for less severe infectious syndromes.

IMPLICATIONS

For patients presenting with suspected bacterial infections, withholding antibiotic therapy until diagnostic results are available and a diagnosis has been established (e.g. by 4-8 h) seems acceptable in most cases unless septic shock or bacterial meningitis are suspected. This approach promotes the use of ecologically favourable antibiotics in the ED, reducing the risks of side effects and selection of resistance.

Rapid syndromic molecular testing in pneumonia: The current landscape and future potential

Community acquired pneumonia (CAP), hospital-acquired pneumonia (HAP) and ventilator associated pneumonia (VAP) are all associated with significant mortality and cause huge expense to health care services around the world. Early, appropriate antimicrobial therapy is crucial for effective treatment. Syndromic diagnostic testing using novel, rapid multiplexed molecular platforms represents a new opportunity for rapidly targeted antimicrobial therapy to improve patient outcomes and facilitate antibiotic stewardship. In this article we review the currently available testing platforms and discuss the potential benefits and pitfalls of rapid testing in pneumonia.

Delay in antibiotic therapy results in fatal disease outcome in murine pneumococcal pneumonia

BACKGROUND

Community-acquired pneumonia (CAP) remains a major cause of death worldwide. Mechanisms underlying the detrimental outcome despite adequate antibiotic therapy and comorbidity management are still not fully understood.

METHODS

To model timely versus delayed antibiotic therapy in patients, mice with pneumococcal pneumonia received ampicillin twice a day starting early (24 h) or late (48 h) after infection. Clinical readouts and local and systemic inflammatory mediators after early and late antibiotic intervention were examined.

RESULTS

Early antibiotic intervention rescued mice, limited clinical symptoms and restored fitness, whereas delayed therapy resulted in high mortality rates. Recruitment of innate immune cells remained unaffected by antibiotic therapy. However, both early and late antibiotic intervention dampened local levels of inflammatory mediators in the alveolar spaces. Early treatment protected from barrier breakdown, and reduced levels of vascular endothelial growth factor (VEGF) and perivascular and alveolar edema formation. In contrast, at 48 h post infection, increased pulmonary leakage was apparent and not reversed by late antibiotic treatment. Concurrently, levels of VEGF remained high and no beneficial effect on edema formation was evident despite therapy. Moreover, early but not late treatment protected mice from a vast systemic inflammatory response.

CONCLUSIONS

Our data show that only early antibiotic therapy, administered prior to breakdown of the alveolar-capillary barrier and systemic inflammation, led to restored fitness and rescued mice from fatal streptococcal pneumonia. The findings highlight the importance of identifying CAP patients prior to lung barrier failure and systemic inflammation and of handling CAP as a medical emergency.

Characteristics and Management of Community-Acquired Pneumonia in the Era of Global Aging

Community-acquired pneumonia (CAP) can occur at any time of life, but its incidence and risk of death are linked to increasing age. CAP in the elderly is a major health problem associated with high rates of readmission, morbidity, and mortality. Since the clinical presentation of pneumonia in the elderly may be atypical, clinicians should suspect pneumonia in older patients presenting symptoms such as falls and altered mental status, fatigue, lethargy, delirium, anorexia, in order to avoid the complications associated with delayed diagnosis and therapy. Streptococcus pneumoniae remains the most frequently reported pathogen in this population. However, particular attention should be paid to patients with risk factors for multidrug resistant pathogens, because a large proportion of elderly persons present multimorbidity. Vaccination is one of the most important preventive approaches for CAP in the elderly. In addition, lifestyle-tailored interventions for different modifiable risk factors will help to reduce the risk of pneumonia in elderly persons. Surveillance of etiological pathogens may improve vaccination policies in this population.

Management of community-acquired pneumonia in immunocompetent adults: updated Swedish guidelines 2017

Based on expert group work, Swedish recommendations for the management of community-acquired pneumonia in adults are here updated. The management of sepsis-induced hypotension is addressed in detail, including monitoring and parenteral therapy. The importance of respiratory support in cases of acute respiratory failure is emphasized. Treatment with high-flow oxygen and non-invasive ventilation is recommended. The use of statins or steroids in general therapy is not found to be fully supported by evidence. In the management of pleural infection, new data show favourable effects of tissue plasminogen activator and deoxyribonuclease installation. Detailed recommendations for the vaccination of risk groups are afforded.

Guidelines-concordant empiric antimicrobial therapy and mortality in patients with severe community-acquired pneumonia requiring mechanical ventilation

BACKGROUND

Community-acquired pneumonia (CAP) has high morbidity and mortality among adults. Several clinical guidelines recommend prompt administration of combined antimicrobial therapy. However, the association between guidelines concordance and mortality in patients with severe pneumonia remains unclear. The present study aimed to examine the impact of guidelines-concordant empiric antimicrobial therapy on 7-day mortality in patients with extremely severe pneumonia who required mechanical ventilation at admission, using a nationwide inpatient database in Japan.

METHODS

Data of CAP patients aged over 20 years who required mechanical ventilation at admission between April 2012 and March 2014 were retrospectively analyzed. Multivariable logistic regression analysis was performed to examine the association between guidelines-concordant empiric antimicrobial therapy and all-cause 7-day mortality, with adjustment for patient backgrounds and pneumonia severity.

RESULTS

There were a total of 3719 eligible patients, 836 (22.5%) of whom received guidelines-concordant combination therapy. Overall, 7-day mortality was 29.5%. Higher 7-day mortality was associated with advanced age, confusion, lower systolic blood pressure, malignant tumor or immunocompromised state, and C-reactive protein ≥20mg/dl or infiltration occupying two-thirds of one lung on chest radiography. After adjustment for these variables, guidelines-concordant combined antimicrobial therapy was associated with significantly lower 7-day mortality (odds ratio: 0.78; 95% confidence interval: 0.65-0.95; P=0.013).

CONCLUSIONS

Adherence to initial empiric treatment as recommended by the guidelines was associated with better short-term prognosis in patients with extremely severe pneumonia who required mechanical ventilation on hospital admission.

Mortality reduction in adult community-acquired pneumonia in the UK (2009-2014): results from the British Thoracic Society audit programme

Community-acquired pneumonia (CAP) is a leading cause of death in the UK. In this analysis of 23 315 cases from the British Thoracic Society national CAP audit, an overall reduction in 30-day inpatient mortality over 6 years was observed-2014 compared with 2009 adjusted OR 0.86 (95% CI 0.68 to 1.08, p for trend 0.004). Significant increases in the proportions of patients who had (a) a chest X-ray and (b) the first antibiotic dose within 4 hours of admission were also observed (3.7% and 11.5% increases respectively). Further reductions in mortality may follow the 2016 National Institute for Health and Care Excellence Pneumonia Quality Standard.