Epidemiology and outcome of severe pneumococcal pneumonia admitted to intensive care unit: a multicenter study

Predictors of mortality in severe pneumonia patients: a systematic review and meta-analysis

BACKGROUND

Severe pneumonia has consistently been associated with high mortality. We sought to identify risk factors for the mortality of severe pneumonia to assist in reducing mortality for medical treatment.

METHODS

Electronic databases including PubMed, Web of Science, EMBASE, Cochrane Library, and Scopus were systematically searched till June 1, 2023. All human research were incorporated into the analysis, regardless of language, publication date, or geographical location. To pool the estimate, a mixed-effect model was used. The Newcastle-Ottawa Scale (NOS) was employed for assessing the quality of included studies that were included in the analysis.

RESULTS

In total, 22 studies with a total of 3655 severe pneumonia patients and 1107 cases (30.29%) of death were included in the current meta-analysis. Significant associations were found between age [5.76 years, 95% confidence interval [CI] (3.43, 8.09), P < 0.00001], male gender [odds ratio (OR) = 1.47, 95% CI (1.07, 2.02), P = 0.02], and risk of death from severe pneumonia. The comorbidity of neoplasm [OR = 3.37, 95% CI (1.07, 10.57), P = 0.04], besides the presence of complications such as diastolic hypotension [OR = 2.60, 95% CI (1.45, 4.67), P = 0.001], ALI/ARDS [OR = 3.63, 95% CI (1.78, 7.39), P = 0.0004], septic shock [OR = 9.43, 95% CI (4.39, 20.28), P < 0.00001], MOF [OR = 4.34, 95% CI (2.36, 7.95), P < 0.00001], acute kidney injury [OR = 2.45, 95% CI (1.14, 5.26), P = 0.02], and metabolic acidosis [OR = 5.88, 95% CI (1.51, 22.88), P = 0.01] were associated with significantly higher risk of death among patients with severe pneumonia. Those who died, compared with those who survived, differed on multiple biomarkers on admission including serum creatinine [Scr: + 67.77 mmol/L, 95% CI (47.21, 88.34), P < 0.00001], blood urea nitrogen [BUN: + 6.26 mmol/L, 95% CI (1.49, 11.03), P = 0.01], C-reactive protein [CRP: + 33.09 mg/L, 95% CI (3.01, 63.18), P = 0.03], leukopenia [OR = 2.63, 95% CI (1.34, 5.18), P = 0.005], sodium < 136 mEq/L [OR = 2.63, 95% CI (1.34, 5.18), P = 0.005], albumin [- 5.17 g/L, 95% CI (- 7.09, - 3.25), P < 0.00001], PaO2/FiO2 [- 55.05 mmHg, 95% CI (- 60.11, - 50.00), P < 0.00001], arterial blood PH [- 0.09, 95% CI (- 0.15, - 0.04), P = 0.0005], gram-negative microorganism [OR = 2.56, 95% CI (1.17, 5.62), P = 0.02], and multilobar or bilateral involvement [OR = 3.65, 95% CI (2.70, 4.93), P < 0.00001].

CONCLUSIONS

Older age and male gender might face a greater risk of death in severe pneumonia individuals. The mortality of severe pneumonia may also be significantly impacted by complications such diastolic hypotension, ALI/ARDS, septic shock, MOF, acute kidney injury, and metabolic acidosis, as well as the comorbidity of neoplasm, and laboratory indicators involving Scr, BUN, CRP, leukopenia, sodium, albumin, PaO2/FiO2, arterial blood PH, gram-negative microorganism, and multilobar or bilateral involvement.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO Protocol Number: CRD 42023430684.

Meningitis in critically ill patients admitted to intensive care unit for severe community-acquired pneumococcal pneumonia

BACKGROUND

Although it has been reported that patients with pneumococcal pneumonia may develop meningitis, lumbar puncture is not systematically recommended in these patients, even in patients with associated bacteremia or invasive pneumococcal disease. The aim of this study was to determine the characteristics and outcomes of patients admitted to intensive care unit (ICU) for pneumococcal community-acquired pneumonia who developed meningitis.

METHODS

We retrospectively included all consecutive patients admitted to our ICU from January 2006 to December 2020 for severe pneumococcal community-acquired pneumonia according to American Thoracic Society criteria. Meningitis was defined as pleocytosis > 5 cells/mm3 or a positive culture of cerebrospinal fluid for Streptococcus pneumoniae in lumbar puncture. The primary endpoint was the proportion of patients with meningitis during their ICU stay.

RESULTS

Overall, 262 patients [64(52-75) years old] were included: 154(59%) were male, 80(30%) had chronic respiratory disease, 105(39%) were immunocompromised and 6(2%) were vaccinated against S. pneumoniae. A lumbar puncture was performed in 88(34%) patients with a delay from ICU admission to puncture lumbar of 10.5 (2.8-24.1) h and after the initiation of pneumococcal antibiotherapy in 81(92%) patients. Meningitis was diagnosed in 14 patients: 16% of patients with lumbar puncture and 5% of patients in the whole population. Patients with meningitis had more frequently human immunodeficiency virus positive status (29 vs. 5%, p = 0.02), neurological deficits on ICU admission (43 vs. 16%, p = 0.03) and pneumococcal bacteremia (71 vs. 30%, p < 0.01) than those without. The ICU mortality rate (14 vs. 13%, p = 0.73) and the mortality rate at Day-90 (21 vs. 15%, p = 0.83) did not differ between patients with and without meningitis. The proportion of patients with neurological disorders at ICU discharge was higher in patients with meningitis (64 vs. 23%, p < 0.001) than in those without. The other outcomes did not differ at ICU discharge, Day-30 and Day-90 between the two groups of patients.

CONCLUSION

Meningitis was diagnosed in 16% of patients with severe pneumococcal community-acquired pneumonia in whom a lumbar puncture was performed, was more frequent in patients with pneumococcal bacteremia and was associated with more frequent neurological disorders at ICU discharge. Further studies are needed to confirm these results.

Population pharmacokinetics and model-based dosing optimization of teicoplanin in elderly critically ill patients with pneumonia

PURPOSE

To evaluate the population pharmacokinetics and pharmacodynamics of teicoplanin in elderly critically ill patients with pneumonia for optimal dosages.

METHODS

Fifteen critically ill patients (9 men) ≥ 60 years received teicoplanin 6 mg/kg for three doses followed by standard maintenance doses (6 mg/kg q24h) with renal dosing adjustment. Serial plasma samples from all patients were analyzed simultaneously by population pharmacokinetic modeling using NONMEM. Probability of target attainment (PTA) was calculated through Monte Carlo simulations for various dosing regimens to achieve adequate systemic exposures.

RESULTS

The median (interquartile range, IQR) age, body mass index, and creatinine clearance (CrCl) was 75 (64-78) years, 22.5 (20.8-25.4) kg/m2, and 64 (47-106) mL/min, respectively. The median (IQR) peak and trough concentration was 46.5 (42.7-51.0) and 8.7 (7.2-9.5) mg/L. The population pharmacokinetic model showed slower clearance (CL) and larger peripheral volume of distribution (V2) in patients with reduced CrCl: CL (L/h) = 0.629 × (CrCl/64)0.656, V2 (L) = 55.7 × (CrCl/64)-0.665. Model-based simulations showed PTAs ≥85% only for higher-dose regimens (12 mg/kg) up to an MIC of 0.5 mg/L.

CONCLUSIONS

Standard teicoplanin dosages for pneumonia may provide inadequate systemic exposures in elderly critically ill patients. High-dose regimens should be considered as empiric therapy or for less susceptible pathogens.

ERS/ESICM/ESCMID/ALAT guidelines for the management of severe community-acquired pneumonia

PURPOSE

Severe community-acquired pneumonia (sCAP) is associated with high morbidity and mortality, and whilst European and non-European guidelines are available for community-acquired pneumonia, there are no specific guidelines for sCAP.

METHODS

The European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID), and Latin American Thoracic Association (ALAT) launched a task force to develop the first international guidelines for sCAP. The panel comprised a total of 18 European and four non-European experts, as well as two methodologists. Eight clinical questions for sCAP diagnosis and treatment were chosen to be addressed. Systematic literature searches were performed in several databases. Meta-analyses were performed for evidence synthesis, whenever possible. The quality of evidence was assessed with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Evidence to Decision frameworks were used to decide on the direction and strength of recommendations.

RESULTS

Recommendations issued were related to diagnosis, antibiotics, organ support, biomarkers and co-adjuvant therapy. After considering the confidence in effect estimates, the importance of outcomes studied, desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention and implications to health equity, recommendations were made for or against specific treatment interventions.

CONCLUSIONS

In these international guidelines, ERS, ESICM, ESCMID, and ALAT provide evidence-based clinical practice recommendations for diagnosis, empirical treatment, and antibiotic therapy for sCAP, following the GRADE approach. Furthermore, current knowledge gaps have been highlighted and recommendations for future research have been made.

ERS/ESICM/ESCMID/ALAT guidelines for the management of severe community-acquired pneumonia

BACKGROUND

Severe community-acquired pneumonia (sCAP) is associated with high morbidity and mortality, and while European and non-European guidelines are available for community-acquired pneumonia, there are no specific guidelines for sCAP.

MATERIALS AND METHODOLOGY

The European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and Latin American Thoracic Association (ALAT) launched a task force to develop the first international guidelines for sCAP. The panel comprised a total of 18 European and four non-European experts, as well as two methodologists. Eight clinical questions for sCAP diagnosis and treatment were chosen to be addressed. Systematic literature searches were performed in several databases. Meta-analyses were performed for evidence synthesis, whenever possible. The quality of evidence was assessed with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Evidence to Decision frameworks were used to decide on the direction and strength of recommendations.

RESULTS

Recommendations issued were related to diagnosis, antibiotics, organ support, biomarkers and co-adjuvant therapy. After considering the confidence in effect estimates, the importance of outcomes studied, desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention and implications to health equity, recommendations were made for or against specific treatment interventions.

CONCLUSIONS

In these international guidelines, ERS, ESICM, ESCMID and ALAT provide evidence-based clinical practice recommendations for diagnosis, empirical treatment and antibiotic therapy for sCAP, following the GRADE approach. Furthermore, current knowledge gaps have been highlighted and recommendations for future research have been made.

Seasonal variation in the detection rate and all-cause in-hospital mortality of AKI in China: A nationwide cohort study

Background

Acute kidney injury (AKI) is a severe clinical syndrome that places a massive burden on medical systems worldwide, yet the seasonality of AKI remains unexplored in China. The aim of this study was to describe the seasonal variation in the detection rate and all-cause in-hospital mortality of AKI in China based on a nationwide cohort study.

Methods

This was a retrospective cohort recruiting a national sample of 7,291 adult patients treated in hospitals in 22 provinces of mainland China during January or July 2013. AKI was defined according to the 2012 Kidney Disease Improving Global Outcomes AKI creatinine criteria or expanded criteria of increase or decrease in serum creatinine level of 50% during the hospital stay. The seasonal group was determined according to the corresponding admission date for each patient. The detection rate of AKI refers to the ratio of identified AKI cases to the total number of adult admissions from the same regional or seasonal group.

Results

Both the detection rate (2.31 vs. 2.08%, p = 0.001) and in-hospital mortality rate (13.3 vs. 10.7%, p = 0.001) of AKI were higher in winter than in summer. The patients with AKI detected in winter had higher proportions of prehistory diseases, cardiac or vascular kidney injury factors, and severe comorbidities than those in summer (all p < 0.05). In the multivariable analysis, winter was an independent risk factor for in-hospital mortality of patients with AKI [odds ratio (OR) = 1.22, 95% confidence interval (CI), 1.03-1.44, p = 0.02] after adjusting for demographic factors, medical history, comorbidity, and climatic confounders. Higher ambient temperature (OR = 0.91, 95% CI, 0.86-0.97, p = 0.002, per 10°C increase), higher relative humidity level (OR = 1.14, 95% CI, 1.04-1.25, p = 0.005, per 10% increase), and living in temperate continental region (OR = 2.18, 95% CI, 1.63-2.91, p < 0.001) were each independently associated with in-hospital mortality.

Conclusion

The detection rate and all-cause in-hospital mortality of AKI showed a winter predominance in patients with AKI in China. Winter appeared to be an independent risk factor for all-cause in-hospital mortality in patients with AKI. Environmental factors, including lower ambient temperature, higher relative humidity level, and living in temperate continental climatic regions, were each independently associated with increased risks of in-hospital mortality in patients with AKI.

Electrochemical Detection for Isothermal Loop-Mediated Amplification of Pneumolysin Gene of Streptococcus pneumoniae Based on the Oxidation of Phenol Red Indicator

A highly sensitive electrochemical methodology for end-point detection of loop-mediated isothermal nucleic acid amplification reactions was developed. It is based on the oxidation process of phenol red (PR), commonly used as a visual indicator. The dependence of its redox process on pH, which changes during amplification, allows performing quantitative measurements. Thus, the change in the oxidation potential of PR during the amplification is used, for the first time, as the analytical signal that correlates with the number of initial DNA copies. As a proof-of-concept, the amplification of the pneumolysin gene from Streptococcus pneumoniae, one of the main pathogens causing community-acquired pneumonia, is performed. Combination of isothermal amplification with electrochemical detection, performed on small-size flexible electrodes, allows easy decentralization. Adaptation to the detection of other pathogens causing infectious diseases would be very useful in the prevention of future epidemics.

Seasonal pattern in elderly hospitalized with acute kidney injury: a retrospective nationwide study in Italy

Purpose

Acute kidney injury (AKI) frequently complicates hospitalization and is associated with in-hospital mortality (IHM). It has been reported a seasonal trend in different clinical conditions. The aim of this study was to evaluate the possible relationship between seasons of the year and IHM in elderly hospitalized patients with AKI.

Methods

We selected all admissions complicated by AKI between 2000 and 2015 recorded in the Italian National Hospital Database. ICD-9-CM code 584.xx identified subjects with age ≥ 65 years and age, sex, comorbidity burden, need of dialysis treatment and IHM were compared in hospitalizations recorded during the four seasons. Moreover, we plotted the AKI observed/expected ratio and percentage of mortality during the study period.

Results

We evaluated 759,720 AKI hospitalizations (mean age 80.5 ± 7.8 years, 52.2% males). Patients hospitalized with AKI during winter months had higher age, prevalence of dialysis-dependent AKI, and number of deceased patients. In whole population IHM was higher in winter and lower in summer, while the AKI observed/expected ratio demonstrated two peaks, one in summer and one in winter. Logistic regression analysis demonstrated that parameters such as age, autumn, winter, comorbidity burden were positively associated with IHM.

Conclusion

We conclude that a seasonality exists in AKI, however, relationship between seasons and AKI could vary depending on the aspects considered. Both autumn and winter months are independent risk factors for IHM in patients with AKI regardless of age, sex and comorbidity burden. On the contrary, summer time reduces the risk of death during hospitalizations with AKI.

Mortality changes for patients with pneumococcal pneumonia from 2012 to 2017 in Japan

INTRODUCTION

Pneumococcal pneumonia has a high morbidity and mortality in adults, especially those ≥65 years old. In the past decade, pneumococcal vaccination programs have been initiated worldwide, however, few data concerning mortality changes are available in pneumococcal pneumonia patients and there are no reports clarifying these current changes in Japan.

METHODS

Japanese patients ≥65 years old hospitalized with pneumococcal pneumonia between April 2012 and March 2018 were analyzed using the Diagnostic Procedure Combination database. In-hospital mortality was evaluated, and the odds ratios for this outcome in each fiscal year compared with that in 2012 was analyzed using multivariable logistic regression models.

RESULTS

Between 2012 and 2017, data of 47,375 pneumococcal pneumonia patients ≥65 years old were extracted. The incidence per 1000 person-years for in-hospital mortality was 60.4 in 2012, 56.8 in 2013, 63.2 in 2014, 56.1 in 2015, 73.0 in 2016, and 67.4 in 2017 and the odds ratios for in-hospital mortality in 2013, 2014, 2015, 2016, and 2017 compared with that in 2012 were 1.00, 1.05, 1.04, 1.06, and 0.98, respectively. There were no significant differences between 2012 and each year from 2013 to 2017. Low BMI; low ADL score; high A-DROP score; comorbid malignancy and heart failure; the coexistence of invasive pneumococcal infection; and the use of invasive mechanical ventilation were independent risk factors for in-hospital mortality.

CONCLUSIONS

There were no changes in in-hospital mortality in pneumococcal pneumonia patients between 2012 or each year from 2013 to 2017 and further epidemiological observations are necessary.

Etiology of Severe Community Acquired Pneumonia in Adults Identified by Combined Detection Methods: A Multi-center Prospective Study in China

Severe Community Acquired Pneumonia (SCAP) challenges public health globally. Considerable improvements in molecular pathogen testing emerged in the last few years. Our prospective study combinedly used traditional culture, antigen tests, PCR and mNGS in SCAP pathogen identification with clinical outcomes. From June 2018 to December 2019, we conducted a multi-centre prospective study in 17 hospitals of SCAP patients within 48 hours of emergency room stay or hospitalization in China. All clinical data were uploaded into an online database. Blood, urine and respiratory specimens were collected for routine culture, antigen detection, PCR and mNGS as designed appropriately. Aetiology confirmation was made by the local attending physician group and scientific committee according to microbiological results, clinical features, and response to the treatment. Two hundred seventy-five patients were included for final analysis. Combined detection methods made identification rate up to 74.2% (222/299), while 14.4% (43/299) when only using routine cultures and 40.8% (122/299) when not using mNGS. Influenza virus (23.2%, 46/198), S. pneumoniae (19.6%, 39/198), Enterobacteriaceae (14.6%, 29/198), Legionella pneumophila (12.6%, 25/198), Mycoplasma pneumoniae (11.1%, 22/198) were the top five common pathogens. The in-hospital mortality of patients with pathogen identified and unidentified was 21.7% (43/198) and 25.9% (20/77), respectively. In conclusion, early combined detection increased the pathogen identification rate and possibly benefitted survival. Influenza virus, S. pneumoniae, Enterobacteriaceae was the leading cause of SCAP in China, and there was a clear seasonal distribution pattern of influenza viruses. Physicians should be aware of the emergence of uncommon pathogens, including Chlamydia Psittaci and Leptospira.

Comparison of prognostic factors between bacteraemic and non-bacteraemic critically ill immunocompetent patients in community-acquired severe pneumococcal pneumonia: a STREPTOGENE sub-study

Background

The presence of bacteraemia in pneumococcal pneumonia in critically ill patients does not appear to be a strong independent prognostic factor in the existing literature. However, there may be a specific pattern of factors associated with mortality for ICU patients with bacteraemic pneumococcal community-acquired pneumonia (CAP). We aimed to compare the factors associated with mortality, according to the presence of bacteraemia or not on admission, for patients hospitalised in intensive care for severe pneumococcal CAP.

Methods

This was a post hoc analysis of data from the prospective, observational, multicentre STREPTOGENE study in immunocompetent Caucasian adults admitted to intensive care in France between 2008 and 2012 for pneumococcal CAP. Patients were divided into two groups based on initial blood culture (positive vs. negative) for Streptococcus pneumoniae. The primary outcome was hospital mortality, which was compared between the two groups using odds ratios according to predefined variables to search for a prognostic interaction present in bacterial patients but not non-bacteraemic patients. Potential differences in the distribution of serotypes between the two groups were assessed. The prognostic consequences of the presence or not of initial bi-antibiotic therapy were assessed, specifically in bacteraemic patients.

Results

Among 614 included patients, 274 had a blood culture positive for S. pneumoniae at admission and 340 did not. The baseline difference between the groups was more frequent leukopaenia (26% vs. 14%, p = 0.0002) and less frequent pre-hospital antibiotic therapy (10% vs. 16.3%, p = 0.024) for the bacteraemic patients. Hospital mortality was not significantly different between the two groups (p = 0.11). We did not observe any prognostic factors specific to the bacteraemic patient population, as the statistical comparison of the odds ratios, as an indication of the association between the predefined prognostic parameters and mortality, showed them to be similar for the two groups. Bacteraemic patients more often had invasive serotypes but less often serotypes associated with high case fatality rates (p = 0.003). The antibiotic regimens were similar for the two groups. There was no difference in mortality for patients in either group given a beta-lactam alone vs. a beta-lactam combined with a macrolide or fluoroquinolone.

Conclusion

Bacteraemia had no influence on the mortality of immunocompetent Caucasian adults admitted to intensive care for severe pneumococcal CAP, regardless of the profile of the associated prognostic factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00936-z.

Health economic evaluation of introducing a PPSV23-based vaccination programme to adults aged 65 and above, and an extension to the 60-64 age group in Denmark

BACKGROUND

To estimate the health economic consequences of the recently introduced PPSV23 vaccination programme for persons aged 65+ in Denmark and of a potential extension of the programme to include persons aged 60-64 years.

RESEARCH DESIGN AND METHODS

A Markov model was adapted to the Danish healthcare setting to simulate the epidemiological and economic burden of invasive pneumococcal disease and non-bacteremic pneumococcal pneumonia using information from published sources and Danish databases.

RESULTS

We found that the recent introduction of an age-based vaccination programme offering PPSV23 vaccination to the population of persons aged 65+ in Denmark will lead to a societal gain of EUR 72.0 million and prevent 19,707 cases of pneumococcal disease and 1,308 deaths per 1 million persons during the five-year study period.Similarly, we estimate that extending the programme to include persons aged 60-64 will lead to a gain of EUR 14.6 million per 1 million persons and prevent an additional 6,223 cases of pneumococcal disease and 185 deaths.

CONCLUSION

The recent introduction of the age-based vaccination programme offering PPSV23 vaccination to all persons aged 65+ in Denmark is cost-effective. This is also the case if the programme is extended to include persons aged 60-64.

Clinical characteristics and outcomes of community-acquired pneumonia in western Saudi Arabia: A four-year retrospective analysis of medical records

BACKGROUND

Community-acquired pneumonia (CAP) is a significant cause of morbidity and mortality, especially for the elderly and people who suffer from chronic conditions. This study was conducted to assess the clinical and microbiological characteristics and disease outcomes associated with the occurrence of CAP.

METHODS

This retrospective chart review was conducted at King Abdulaziz Medical City, Jeddah, Saudi Arabia. Cases with documented clinical diagnosis of CAP during the period from 2016 to 2019 were included. Data were collected on demographic, clinical, and microbiological characteristics, used antimicrobials and patients' outcomes, including length of hospital stay, intensive care unit admission, and mortality. Multivariate regression analysis was performed to identify risk factors for increased length of hospital stay.

RESULTS

A total of two hundred and eighteen CAP episodes were identified. Patients had a median age of 64.5 years, and 54.1% were males. Microbiological diagnosis was established in 33 patients (15.1%). Admission to ICU and diagnosis of a neurological disease were significantly associated with longer hospital stay (>7 days). An average of 2.7 antimicrobials were used per patient, and the most common antibiotics used were Piperacillin/Tazobactam (46.3%), Doxycycline (44%), then Ceftriaxone (42.7%). Four patients (1.8%) died during hospital stay.

CONCLUSIONS

This retrospective analysis of CAP cases identified a lack of microbiological diagnosis and increased burden associated with disease severity and the need for hospitalization. The ability to identify CAP at an earlier stage will be a cornerstone to mitigate its impact on the healthcare system and ICU units.

Meta-analysis of the effects of combination therapies of β-lactams and fluoroquinolones or macrolides in the treatment of community-acquired pneumonia

OBJECTIVE

The purpose of this study was to identify the optimal treatment plan for hospitalized patients with community-acquired pneumonia (CAP) by evaluating related studies on combination therapies of β-lactams/macrolides (BLM) and β-lactams/fluoroquinolones (BLFQ) in the treatment of CAP.

METHODS

A meta-analysis was performed on studies with mortality rates as the main result using PubMed, Scopus, Cochrane, and other journal databases. The literature was evaluated using GRADE and MiNORS.

RESULTS

A total of 17 studies were included. Various studies included the effects of combination therapy and mortality rates of β-lactam, fluoroquinolones and macrolides. The quality of currently available evidence was low. In the preliminary data analysis, the mortality rate of BLFQ was higher than that of BLM (RR = 1.33, 95% CI: 1.15-1.54, I² = 28%). No difference was observed in patients with bacteremia and septic shock. In a meta-analysis with adjusted mortality rates, no significant difference was shown in two therapies (RR = 1.26, 95% CI: 0.95-1.67, I² = 43%).

CONCLUSION

The related studies on the relative effects of BLFQ and BLM therapies in the treatment of CAP hospitalized patients have low-quality evidence. The current data indicate that BLFQ combination therapy is associated with higher mortality rates.

The expansive effects of polyamines on the metabolism and virulence of Streptococcus pneumoniae

Polyamines are common intracellular metabolites of nearly all cells, and their conservation across a vast diversity of cells suggests critical roles for these compounds in cellular physiology. Most intracellular polyamines are associated with RNA and, subsequently, polyamines have significant effects on transcription and translation. Putrescine and spermidine are the most common polyamines in bacteria. Intracellular polyamine pools in bacteria are tightly controlled by both de novo synthesis and transport. Polyamine homeostasis is emerging as a critical parameter of multiple pathways and physiology with substantial impact on bacterial pathogenesis, including the important human pathogen Streptococcus pneumoniae. Modulation of polyamine metabolism in pneumococci is an important regulator of central metabolism. It has broad effects on virulence factors such as capsule as well as stress responses that ultimately impact the survival of pneumococcus in a host. Polyamine transport protein as a single antigen or in combination with other pneumococcal proteins is shown to be an efficacious immunogen that protects against nasopharyngeal colonization, and invasive disease. A comprehensive description of polyamine metabolic pathways and their intersection with pneumococcal pathogenesis will undoubtedly point to novel approaches for treatment and prevention of pneumococcal disease.

Kidney disease and mortality in patients with respiratory tract infections: a systematic review and meta-analysis

BACKGROUND

Respiratory tract infections (RTIs) are a common reason for people to seek medical care. RTIs are associated with high short-term mortality. Inconsistent evidence exists in the association between the presence of kidney disease and the risk of death in patient with RTIs.

METHODS

We searched the PubMed, Cochrane Library and Embase databases from inception through April 2019 for cohort and case-control studies investigating the presence of kidney disease (defined as medical diagnosis of kidney disease, reduced estimated glomerular filtration rate or creatinine clearance, elevated serum creatinine and proteinuria) on mortality in adults with RTIs in different settings including community, inpatient and intensive care units. We assessed the quality of the included studies using Cochrane Collaboration's tool and conducted a meta-analysis on the relative risk (RR) of death.

RESULTS

Of 5362 records identified, 18 studies involving 16 676 participants met the inclusion criteria, with 15 studies investigating pneumonia and 3 studies exploring influenza. The risk of bias in the available evidence was moderate. Most [17/18 (94.5%)] of studies reported positive associations of underlying chronic kidney disease with mortality. The pooled adjusted risk for all-cause mortality in patients with RTIs almost doubled [RR 1.96 (95% confidence interval 1.48-2.59)] in patients with kidney disease. Associations were consistent across different timings of kidney disease assessment and provenances of RTIs (community-acquired or healthcare-associated).

CONCLUSIONS

The presence of kidney disease is associated with higher mortality among people with RTIs, especially in those with pneumonia. The presence of kidney disease might be taken into account when considering admission for patients who present with RTIs.

Seasonality of acute kidney injury in a tertiary hospital academic center: an observational cohort study

BACKGROUND

The aim of our study was to describe seasonal trends of acute kidney injury (AKI) and its relationship with weather conditions in a hospitalized population.

METHODS

We retrospectively collected demographic (age, sex), clinical (ICD-9-CM codes of diagnosis discharge) and laboratory data (creatinine values) from the inpatient population admitted to Fondazione Policlinico Universitario A. Gemelli IRCCS between January 2010 and December 2014 with inclusion of all patients ≥18 years with at least two values available for creatinine. The outcome of interest was AKI development, defined according to creatinine kinetics criteria. The exposures of interest were the months and seasons of the year; air temperature and humidity level were also evaluated. Log-binomial regression models adjusted for age, sex, eGFR, comorbidities, Charlson/Deyo index score, year of hospitalization were used to estimate risk ratios (RR) and 95% confidential intervals (CI).

RESULTS

A total of 64,610 patients met the inclusion criteria. AKI occurred in 2864 (4.4%) hospital admissions. After full adjustment, winter period was associated with increased risk of AKI (RR 1.16, 95% CI 1.05, 1.29, p=0.003). Lower air temperature and higher humidity level were associated with risk of AKI, however in multivariable-adjusted models only higher humidity level showed a significant and independent association.

CONCLUSIONS

AKI is one of the most common complications of hospitalized populations with a defined seasonal pattern and a significant increase in incidence during wintertime; weather conditions, particularly higher humidity level, are independent predictors of AKI and could partially justify the observed seasonal variations.

The potential role of pneumococcal conjugate vaccine in reducing acute respiratory inflammation in community-acquired pneumococcal pneumonia

Background

Pneumococcal conjugate vaccine (PCV) reduces both invasive pneumococcal disease (IPD) and other pneumococcal infections worldwide. We investigated the impact of stepwise implementation of childhood PCV programs on the prevalence of pneumococcal pneumonia, severity of acute inflammation, and associations between breakthrough pneumonia and pneumococcal serotypes in Taiwan.

Methods

In total, 983 children diagnosed with community-acquired pneumococcal pneumonia were enrolled between January 2010 and December 2015.

Results

Proportions of pneumococcal vaccinations increased each year in age-stratified groups with PCV7 (32.2%) as the majority, followed by PCV13 (12.2%). The proportion of pneumococcal pneumonia decreased each year in age-stratified groups, especially in 2–5 year group. Serotype 19A is the leading serotype either in vaccinated (6.4%) or unvaccinated patients (5.2%). In particular, vaccinated patients had significantly higher lowest WBC, lower neutrophils, lower lymphocytes and lower CRP values than non-vaccinated patients (p < 0.05). After stratifying patients by breakthrough infection, those with breakthrough pneumococcal infection with vaccine coverage serotypes had more severe pneumonia disease (p < 0.05).

Conclusion

Systematic childhood pneumococcal vaccination reduced the prevalence of community-acquired pneumococcal pneumonia, especially in 2–5 year group. Serotype 19A was the major serotype for all vaccine types in patients with pneumococcal pneumonia and severity of acute inflammatory response was reduced in vaccinated patients.

Standing orders program of pneumococcal vaccination for hospitalized elderly patients in Hong Kong: A cost-effectiveness analysis

BACKGROUND

Clinical studies support a standing orders program (SOP) to improve vaccine uptake. We aimed to examine the potential cost-effectiveness of a pneumococcal vaccination SOP for Hong Kong elderly in a hospital setting.

METHODS

A decision-analytic model was designed to compare the outcomes of inpatients 65 years of age or older who were eligible for pneumococcal vaccination. Two vaccination approaches were evaluated: (1) vaccination SOP, and (2) no program (control group). Outcome measures included direct medical costs, invasive pneumococcal disease-associated mortality rates, quality-adjusted life year (QALY) losses, and incremental cost per QALY saved (ICER).

RESULTS

In the base-case analysis, mortality and QALY losses were lower and costs were higher in the SOP group when compared to the control group. The base-case ICER of the SOP group was $59,762 (all dollar amounts are in US$) per QALY saved. One-way sensitivity analyses found ICER to be sensitive to the probability of invasive pneumococcal disease among the unvaccinated elderly. Using 1× the gross domestic product per capita of Hong Kong ($43,497) and the United States ($150,000) as willingness-to-pay thresholds, SOPs were the preferred option in 37.2% and 97.5% of 10,000 Monte Carlo simulations, respectively.

CONCLUSIONS

The pneumococcal vaccination SOP for hospitalized elderly patients appeared to reduce QALY losses at a higher cost. The cost-effective acceptance of SOPs is highly dependent on the willingness-to-pay threshold.

Seasonality of acute kidney injury incidence and mortality among hospitalized patients

Background

Understanding disease seasonality is important for improving clinical practice, hospital resource utilization and community-based preventive care. However, no studies have investigated the seasonality of acute kidney injury (AKI).

Methods

In the Tokushukai Medical Database, which includes 38 Japanese community hospitals, we identified hospitalized patients with AKI based on the Kidney Disease: Improving Global Outcomes serum creatinine criteria from January 2012 to December 2014. We plotted the number and proportion of patients with AKI among hospitalized patients by month of hospital admission. Subgroup analyses were conducted by the admission diagnosis category, timing of AKI diagnosis and age. We also examined the association between month of hospital admission and AKI, adjusting for patient characteristics and AKI risk factors. Finally, we assessed seasonal variations in disease severity and 30-day mortality of patients with AKI.

Results

We identified 81 279 (14.6%) patients with AKI among 555 940 hospitalized patients. The proportion of patients with AKI was highest in January (16.7%) and lowest in June (13.4%). Subgroup analyses suggested that the seasonality of AKI incidence was driven by community-acquired AKI associated with the admission diagnosis of cardiovascular and pulmonary diseases among older patients. The adjusted odds ratio for AKI (January versus June) was 1.24 (95% confidence interval, 1.17-1.31). Patients with AKI showed a larger number of failing organs in winter, and their 30-day mortality was 16.4% in spring, 14.5% in summer, 15.6% in autumn and 18.4% in winter.

Conclusion

AKI is more common among hospitalized patients and patients with AKI are more severely ill in winter.

CAL02, a novel antitoxin liposomal agent, in severe pneumococcal pneumonia: a first-in-human, double-blind, placebo-controlled, randomised trial

BACKGROUND

Severe community-acquired pneumonia caused by Streptococcus pneumoniae is associated with high morbidity and mortality rates. CAL02, a novel antitoxin agent with an unprecedented mode of action, consists of liposomes that capture bacterial toxins known to dysregulate inflammation, cause organ damage, and impede immune defence. We aimed to assess the safety of CAL02 as an add-on therapy to antibiotics.

METHODS

This randomised, double-blind, multicentre, placebo-controlled trial was done in ten intensive care units (ICUs) in France and Belgium (but only six units enrolled patients), in patients with severe community-acquired pneumococcal pneumonia who required ICU admission and had been identified as being infected with S pneumoniae. We randomly assigned participants in two stages-the first stage randomly assigned six patients (1:1) to either low-dose CAL02 or placebo, and the second stage randomly assigned 18 patients (14:4) to either high-dose CAL02 or placebo, and stratified in four blocks (4:1, 4:1, 3:1, and 3:1), in addition to standard of care. Block randomisation was done with a computer-generated random number list. Participants, investigators, other site study personnel, the sponsor, and the sponsor's designees involved in study management and monitoring were masked to the randomisation list and treatment assignment. Patients were treated with low-dose (4 mg/kg) or high-dose (16 mg/kg) CAL02 or placebo (saline), in addition to standard antibiotic therapy. Two intravenous doses of study treatment were infused, with a 24 h interval, at a concentration of 10 mg/mL, stepwise, over a maximum of 2 h on days 1 and 2. The primary objective of the study was to assess the safety and tolerability of low-dose and high-dose CAL02 in patients with severe community-acquired pneumonia treated with standard antibiotic therapy, and the primary analysis was done on the safety population (all patients who received at least one dose of the study treatment). Efficacy was a secondary outcome. This trial is registered with ClinicalTrials.gov, number NCT02583373.

FINDINGS

Between March 21, 2016, and Jan 13, 2018, we screened 280 patients with community-acquired pneumonia. 19 patients were enrolled and randomly assigned, resulting in 13 patients in the CAL02 groups (three assigned to low-dose CAL02 and ten assigned to high-dose CAL02) and six in the placebo group. One patient randomly assigned to placebo was allocated to the wrong treatment group and received high-dose CAL02 instead of placebo. Thus, 14 patients received CAL02 (three received low-dose CAL02 and 11 received high-dose CAL02) and five patients received placebo, constituting the safety population. At baseline, the mean APACHE II score for the total study population was 21·5 (SD 4·9; 95% CI 19·3-23·7) and 11 (58%) of 19 patients had septic shock. Adverse events occurred in 12 (86%) of 14 patients in the CAL02 treatment groups combined and all five (100%) patients in the placebo group. Serious adverse events occurred in four (29%) of 14 patients in the CAL02 treatment groups combined and two (40%) of five patients in the placebo group. One non-serious adverse event (mild increase in triglycerides) in a patient in the high-dose CAL02 group was reported as related to study drug. However, analysis of the changes in triglyceride levels in the CAL02 groups compared with the placebo group revealed no correlation with administration of CAL02. No adverse events were linked to local tolerability events. All patients, apart from one who died in the low CAL02 group (death not related to the study drug) achieved clinical cure at the test of cure visit between days 15 and 22. The sequential organ failure assessment score decreased by mean 65·0% (95% CI 50·7-79·4) in the combined CAL02 groups compared with 29·2% (12·8-45·5) in the placebo group between baseline and day 8.

INTERPRETATION

The nature of adverse events was consistent with the profile of the study population and CAL02 showed a promising safety profile and tolerability. However, the difference between high-dose and low-dose CAL02 could not be assessed in this study. Efficacy was in line with the expected benefits of neutralising toxins. The results of this study support further clinical development of CAL02 and provide a solid basis for a larger clinical study.

FUNDING

Combioxin.

Early improvement in severely ill patients with pneumonia treated with ceftobiprole: a retrospective analysis of two major trials

BACKGROUND

Patients with pneumonia who are elderly or severely ill are at a particularly high risk of mortality. This post hoc retrospective analysis of data from two Phase III studies evaluated early improvement outcomes in subgroups of high-risk patients with community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP, excluding ventilator-associated pneumonia [VAP]).

METHODS

One study included hospitalised CAP patients randomised to ceftobiprole or ceftriaxone ± linezolid treatment. The other study included HAP patients, who were randomised to ceftobiprole or ceftazidime plus linezolid treatment. The primary outcome was rate of early clinical response (Day 3 in CAP and Day 4 in HAP patients). Additional outcome measures included clinical cure at a test-of-cure visit, 30-day all-cause mortality and safety.

RESULTS

The overall high-risk group comprised 398 CAP patients and 307 HAP patients with risk factors present at baseline. The rate of early response was numerically higher in ceftobiprole-treated patients vs comparator-treated patients in the following high-risk groups: CAP patients aged ≥75 years (16.3% difference, 95% confidence interval [CI]: 1.8, 30.8); CAP patients with COPD (20.1% difference, 95% CI: 8.8, 31.1); all high-risk HAP patients (12.5% difference, 95% CI: 3.5, 21.4); HAP patients with >10 baseline comorbidities (15.3% difference, 95% CI: 0.3, 30.4).

CONCLUSIONS

Previous studies show that ceftobiprole is an efficacious therapy for patients with pneumonia who are at high risk of poor outcomes. This post hoc analysis provides preliminary evidence that ceftobiprole treatment may have advantages over other antibiotics in terms of achieving early improvement in high-risk patients with HAP (excluding VAP) and in some subgroups of high-risk CAP patients.

TRIAL REGISTRATION

NCT00210964 : registered September 21, 2005; NCT00229008 : registered September 29, 2005; NCT00326287 : registered May 16, 2006.

Host-pathogen interactions and prognosis of critically ill immunocompetent patients with pneumococcal pneumonia: the nationwide prospective observational STREPTOGENE study

PURPOSE

To assess the relative importance of host and bacterial factors associated with hospital mortality in patients admitted to the intensive care unit (ICU) for pneumococcal community-acquired pneumonia (PCAP).

METHODS

Immunocompetent Caucasian ICU patients with PCAP documented by cultures and/or pneumococcal urinary antigen (UAg Sp) test were included in this multicenter prospective study between 2008 and 2012. All pneumococcal strains were serotyped. Logistic regression analyses were performed to identify risk factors for hospital mortality.

RESULTS

Of the 614 patients, 278 (45%) had septic shock, 270 (44%) had bacteremia, 307 (50%) required mechanical ventilation at admission, and 161 (26%) had a diagnosis based only on the UAg Sp test. No strains were penicillin-resistant, but 23% had decreased susceptibility. Of the 36 serotypes identified, 7 accounted for 72% of the isolates, with different distributions according to age. Although antibiotics were consistently appropriate and were started within 6 h after admission in 454 (74%) patients, 116 (18.9%) patients died. Independent predictors of hospital mortality in the adjusted analysis were platelets ≤ 100 × 10⁹/L (OR, 7.7; 95% CI, 2.8-21.1), McCabe score ≥ 2 (4.58; 1.61-13), age > 65 years (2.92; 1.49-5.74), lactates > 4 mmol/L (2.41; 1.27-4.56), male gender and septic shock (2.23; 1.30-3.83 for each), invasive mechanical ventilation (1.78; 1-3.19), and bilateral pneumonia (1.59; 1.02-2.47). Women with platelets ≤ 100 × 10⁹/L had the highest mortality risk (adjusted OR, 7.7; 2.8-21).

CONCLUSIONS

In critically ill patients with PCAP, age, gender, and organ failures at ICU admission were more strongly associated with hospital mortality than were comorbidities. Neither pneumococcal serotype nor antibiotic regimen was associated with hospital mortality.

Pneumococcal sepsis requiring mechanical ventilation: Cohort study in 38 patients with rapid progression to septic shock

BACKGROUND

The aim was to study the course of severe pneumococcal sepsis in patients who rapidly developed septic shock with multiorgan failure.

METHODS

Combined retrospective and prospective cohort study of all patients with pneumococcal sepsis requiring mechanical ventilation admitted to our Medical Intensive Care Unit at Oslo University Hospital Ullevaal, during an 8-year period (01 January 2006 to 31 December 2013). The inclusion criteria were growth of Streptococcus pneumoniae in blood culture and respiratory failure treated with invasive mechanical ventilation.

RESULTS

Thirty-eight patients were included. Median age was 57 years (interquartile range 49-68, range 22-79). For 84% (32/38), it took <24 hours from the first medical evaluation until they were in septic shock. Initial clinical features were variable; none were treated with antibiotics before hospital admission. Median Sequential Organ Failure Assessment (SOFA) score at admission was 11 (range 1-15) and maximum 15 (range 5-22), all patients developed multiorgan failure. Mutilating complications were seen in 47% (18/38) of the patients: six with amputations, 11 had adverse neurological complications and one patient both. In-hospital mortality was 40% (15/38), 20% (8/38) survived with sequelae and 40% (15/38) returned to their habitual state. Poor outcome was associated with meningitis, disseminated intravascular coagulation, and gastrointestinal symptoms.

CONCLUSION

In this patient cohort with pneumococcal sepsis and respiratory failure rapid development of septic shock was seen in all cases, even in young healthy individuals. Initial clinical features were variable; none were treated with antibiotics before admission. Mortality was high (40%), as was morbidity with limb amputations and neurological complications.

[Corticosteroids in community acquired pneumonia: Where are we in 2018?]

Community-acquired pneumonia (CAP) is a common infectious disease and one of the main causes of mortality worldwide. Despite an improvement in management globally, mortality remains high especially in severe forms of CAP. Adequate early antibiotics remain the cornerstone of the treatment but adjuvant corticosteroid administration is being considered to counterbalance the systemic inflammatory reaction and modulate the immune response. In the last ten years, several clinical trials and meta-analyses have been conducted in severe and non-severe CAP to assess the efficacy of corticosteroids. The benefits on the duration of hospitalization and the time to clinical stability are quite small and early mortality does not seem to be improved. Corticosteroids should not, therefore, be used routinely in patients with CAP, even in severe cases. However, new therapeutic trials are currently underway.

Readmissions of adults within three age groups following hospitalization for pneumonia: Analysis from the Nationwide Readmissions Database

Background

While 30-day readmissions following hospitalization for pneumonia have been well-studied in the elderly, their burden in young adults remains poorly understood.

Objective

To study patterns of readmissions following hospitalization for pneumonia across age groups and insurance payers.

Methods

In the Nationwide Readmission Database for the years 2013 and 2014 we identified all adults (≥18 years) discharged alive after a hospitalization with the primary diagnosis of pneumonia, and examined rates of readmissions within 30-days of discharge. Using covariates included in the Center for Medicare & Medicaid Services risk-adjustment model for pneumonia readmissions in a multivariable regression model for survey data, we identified predictors of 30-day readmission.

Results

We identified 629,939 index pneumonia hospitalizations with a weighted estimate of 1,472,069 nationally. Overall, 16.2% of patients were readmitted within 30 days of their hospitalization for pneumonia, with 30-day readmission rates of 12.4% in the 18–44 year age-group, 16.1% in the 45–64 year age-group, and 16.7% in the ≥65-year age-group. In risk-adjusted analyses, compared with elderly, middle-aged adults were more likely to be readmitted (risk-adjusted OR 1.05, 95% CI 1.03–1.07). Mean cost per readmission was also highest for this age group at $15,976.

Conclusion

Middle-aged adults experience substantial rates of 30-day readmission that are comparable to those over 65 years of age, with a higher cost per readmission event. Future efforts are needed to identify potential interventions to alleviate the high burden of pneumonia readmissions in middle-aged adults.

Mechanical ventilation and Streptococcus pneumoniae pneumonia alter mitochondrial homeostasis

Required mechanical ventilation (MV) may contribute to bacterial dissemination in patients with Streptococcus pneumoniae pneumonia. Significant variations in plasma mitochondrial DNA (mtDNA) have been reported in sepsis according to the outcome. The impact of lung stretch during MV was addressed in a model of pneumonia. Healthy or S. pneumoniae infected rabbits were submitted to MV or kept spontaneously breathing (SB). Bacterial burden, cytokines release, mitochondrial DNA levels, integrity and transcription were assessed along with 48-hour mortality. Compared with infected SB rabbits, MV rabbits developed more severe pneumonia with greater concentrations of bacteria in the lungs, higher rates of systemic dissemination, higher levels of circulating inflammatory mediators and decreased survival. Pulmonary mtDNA levels were significantly lower in infected animals as compared to non-infected ones, whenever they were SB or MV. After a significant early drop, circulating mtDNA levels returned to baseline values in the infected SB rabbits, but remained low until death in the MV ones. Whole blood ex-vivo stimulation with Streptococcus pneumoniae resulted in a reduction of polymorphonuclear leukocytes mitochondrial density and plasma mtDNA concentrations. Thus, persistent mitochondrial depletion and dysfunction in the infected animals submitted to MV could account for their less efficient immune response against S. pneumoniae.

Twenty-year trend in mortality among hospitalized patients with pneumococcal community-acquired pneumonia

BACKGROUND

There is only limited information on mortality over extended periods in hospitalized patients with pneumococcal community-acquired pneumonia (CAP). We aimed to evaluate the 30-day mortality and whether is changed over a 20-year period among immunocompetent adults hospitalized with pneumococcal CAP.

METHODS

We conducted a retrospective observational study of data that were prospectively collected at the Hospital Clinic of Barcelona of all adult patients hospitalized with diagnosis of pneumococcal CAP over a 20-year period. To aid analysis, results were divided into four periods of 5 years each (1997-2001, 2002-2006, 2007-2011, 2012-2016). The primary outcome was 30-day mortality, but secondary outcomes included intensive care unit (ICU) admission, lengths of hospital and ICU-stays, ICU-mortality, and need of mechanical ventilation.

RESULTS

From a cohort of 6,403 patients with CAP, we analyzed the data for 1,120 (17%) adults with a diagnosis of pneumococcal CAP. Over time, we observed decreases in the rates of alcohol consumption, smoking, influenza vaccination, and older patients (age ≥65 years), but increases in admissions to ICU and the need for non-invasive mechanical ventilation. The overall 30-day mortality rate was 8% (95% confidence interval, 6%-9%; 84 of 1,120 patients) and did not change significantly between periods (p = 0.33). Although, we observed a decrease in ICU-mortality comparing the first period (26%) to the second one (10%), statistical differences disappeared with adjustment (p0.38).

CONCLUSION

Over time, 30-day mortality of hospitalized pneumococcal CAP did not change significantly. Nor did it change in the propensity-adjusted multivariable analysis. Since mortality in pneumococcal pneumonia has remained unaltered for many years despite the availability of antimicrobial agents with proven in vitro activity, other non-antibiotic strategies should be investigated.

Combined vitamin C, hydrocortisone, and thiamine therapy for patients with severe pneumonia who were admitted to the intensive care unit: Propensity score-based analysis of a before-after cohort study

PURPOSE

To evaluate the efficacy of combined vitamin C, hydrocortisone, and thiamine in patients with severe pneumonia.

MATERIALS AND METHODS

All consecutive patients with severe pneumonia who were treated with the vitamin C protocol (6 g of vitamin C per day) in June 2017-January 2018 (n = 53) were compared to all consecutive patients with severe pneumonia who were treated in June 2016-January 2017 (n = 46). Propensity score analysis was used to adjust for potential baseline differences between the groups.

RESULTS

In the propensity-matched cohort (n = 36/group), the treated patients had significantly less hospital mortality than the control group (17% vs. 39%; P = 0.04). The vitamin C protocol associated independently with decreased mortality in propensity score-adjusted analysis (adjusted odds ratio = 0.15, 95% confidence interval = 0.04-0.56, P = 0.005). Relative to the control group, the treatment group had a significantly higher median improvement in the radiologic score at day 7 compared with baseline (4 vs. 2; P = 0.045). The vitamin C protocol did not increase the rates of acute kidney injury or superinfection.

CONCLUSIONS

Combined vitamin C, hydrocortisone, and thiamine therapy may benefit patients with severe pneumonia.

Acute respiratory distress syndrome in mechanically ventilated patients with community-acquired pneumonia

Our aim was to assess the incidence, characteristics, aetiology, risk factors and mortality of acute respiratory distress syndrome (ARDS) in intensive care unit (ICU) patients with community-acquired pneumonia (CAP) using the Berlin definition.We prospectively enrolled consecutive mechanically ventilated adult ICU patients with CAP over 20 years, and compared them with mechanically ventilated patients without ARDS. The main outcome was 30-day mortality.Among 5334 patients hospitalised with CAP, 930 (17%) were admitted to the ICU and 432 required mechanical ventilation; 125 (29%) cases met the Berlin ARDS criteria. ARDS was present in 2% of hospitalised patients and 13% of ICU patients. Based on the baseline arterial oxygen tension/inspiratory oxygen fraction ratio, 60 (48%), 49 (40%) and 15 (12%) patients had mild, moderate and severe ARDS, respectively. Streptococcus pneumoniae was the most frequent pathogen, with no significant differences in aetiology between groups. Higher organ system dysfunction and previous antibiotic use were independent risk factors for ARDS in the multivariate analysis, while previous inhaled corticosteroids were independently associated with a lower risk. The 30-day mortality was similar between patients with and without ARDS (25% versus 30%, p=0.25), confirmed by propensity-adjusted multivariate analysis.ARDS occurs as a complication of CAP in 29% of mechanically ventilated patients, but is not related to the aetiology or mortality.

Antimicrobial Resistance Among Streptococcus pneumoniae

Antibiotic resistance in Streptococcus pneumoniae (pneumococcus), the main pathogen responsible for community-acquired pneumonia (CAP), meningitis, bacteremia, and otitis media, is a major concern for clinicians. This pathogen is associated with high rates of morbidity and mortality, especially among children under 2 years old, immunocompromised persons, and the elderly population. The major anti-pneumococcus agents are β-lactams and macrolides, with fluoroquinolones ranking third. The emergence of antibiotic-resistant pneumococcus due to overuse of antibiotics is a global concern. While the discovery of novel classes of antibiotics for the pneumococcus is at a standstill, significant progress in reducing the problem of resistance is associated with antibacterial vaccines. Nevertheless, the World Health Organization recently considered drug-resistant S. pneumoniae as ranking among the 12 bacteria, for which there is an urgent need for new treatments. A challenge is to slow the evolution of new strains that are resistant to the vaccines.

Severe community-acquired pneumonia: Characteristics and prognostic factors in ventilated and non-ventilated patients

BACKGROUND

Patients with severe community-acquired pneumonia (SCAP) and life-threatening acute respiratory failure may require invasive mechanical ventilation (IMV). Since use of IMV is often associated with significant morbidity and mortality, we assessed whether patients invasively ventilated would represent a target population for interventions aimed at reducing mortality of SCAP.

METHODS

We prospectively recruited consecutive patients with SCAP for 12 years. We assessed the characteristics and outcomes of patients invasively ventilated at presentation of pneumonia, compared with those without IMV, and determined the influence of risks factors on mortality with a multivariate weighted logistic regression using a propensity score.

RESULTS

Among 3,719 patients hospitalized with CAP, 664 (18%) had criteria for SCAP, and 154 (23%) received IMV at presentation of pneumonia; 198 (30%) presented with septic shock. In 370 (56%) cases SCAP was diagnosed based solely on the presence of 3 or more IDSA/ATS minor criteria. Streptococcus pneumoniae was the main pathogen in both groups. The 30-day mortality was higher in the IMV, compared to non-intubated patients (51, 33%, vs. 94, 18% respectively, p<0·001), and higher than that predicted by APACHE-II score (26%). IMV independently predicted 30-day mortality in multivariate analysis (adjusted odds-ratio 3·54, 95% confidence interval 1·45-8·37, p = 0·006). Other independent predictors of mortality were septic shock, worse hypoxemia and increased serum potassium.

CONCLUSION

Invasive mechanical ventilation independently predicted 30-day mortality in patients with SCAP. Patients invasively ventilated should be considered a different population with higher mortality for future clinical trials on new interventions addressed to improve mortality of SCAP.

The dilemma of monotherapy or combination therapy in community-acquired pneumonia

SCOPE

To study the factors associated with mortality in hospitalized patients with community-acquired pneumonia treated with monotherapy or combination therapy.

METHODS

PubMed and Scopus were searched. Patients receiving macrolides, β-lactams and fluoroquinolones, as monotherapy or in combination, were included. Meta-analyses and meta-regressions were performed.

RESULTS

Fifty studies were included. Overall, monotherapy was not associated with higher mortality than combination (RR 1.14, 95% CI 0.99-1.32, I² 84%). Monotherapy was associated with higher mortality than combination in North American and retrospective studies. β-lactam monotherapy was associated with higher mortality than β-lactam/macrolide combination in the primary (1.32, 1.12-1.56, I² 85%) and most sensitivity analyses. There was no difference in mortality between fluoroquinolone monotherapy and β-lactam/macrolide combination (0.98, 0.78-1.23, I² 73%). In meta-regressions, the moderators that could partially explain the observed statistical heterogeneity were the frequency of cancer patients (P = .03) and Pneumonia Severity Index score IV (P = .008).

CONCLUSION

Due to the considerable heterogeneity and inclusion of unadjusted data, it is difficult to recommend a specific antibiotic regimen over another. Specific antibiotic regimens, study design and the characteristics of the population under study seem to influence the reported outcomes.

Bacteremia Prediction Model for Community-acquired Pneumonia: External Validation in a Multicenter Retrospective Cohort

OBJECTIVE

Many studies have described constructing a prediction model for bacteremia in community-acquired pneumonia (CAP), but these studies were not validated in external heterogeneous groups. The objective of this study was to test the generalizability of a previous bacteremia prediction model for CAP by external validation.

METHODS

This multicenter retrospective cohort analysis was performed in eight tertiary urban hospital emergency departments (EDs). We reviewed adult patients who were hospitalized after presentation to the ED with CAP. We categorized the enrolled patients into three groups according to the bacteremia prediction model score and calculated the number of patients with or without a blood culture-positive result. We performed a multivariable analysis to identify significant predictors for bacteremia.

RESULTS

Among the enrolled 2,001 patients, 1,592 (79.6%), 371 (18.5%), and 38 (1.9%) were stratified to a low-, moderate-, and high-risk group, respectively, and this proportion was similar with previous study. Each group had a bacteremia-positive rate as follows: 1.2% for the low-risk group, 7.2% for the moderate-risk group, and 31.5% for the high-risk group. The area under the receiver operating characteristic curve for the bacteremia model in the external validation cohort was 0.81, and there was no significant difference with that of the previous internal validation cohort (p = 0.246). Assuming that blood cultures were not performed in the low-risk patients, the sensitivity and specificity of this model were 0.68 and 0.81, respectively. Additionally, the positive predictive value and negative predictive value were 9.54 and 98.87%, respectively. A platelet count less than 130 × 10⁹ cells/L, albumin less than 3.3 mg/dL, and C-reactive protein greater than 17 mg/dL were identified as significant predictors with a sensitivity and specificity of 0.70 and 0.83, respectively.

CONCLUSION

The bacteremia prediction model was well validated in the general population and could help physicians make the decision to reduce the number of blood cultures in patients with CAP.

Pneumolysin as a potential therapeutic target in severe pneumococcal disease

Acute pulmonary and cardiac injury remain significant causes of morbidity and mortality in those afflicted with severe pneumococcal disease, with the risk for early mortality often persisting several years beyond clinical recovery. Although remaining to be firmly established in the clinical setting, a considerable body of evidence, mostly derived from murine models of experimental infection, has implicated the pneumococcal, cholesterol-binding, pore-forming toxin, pneumolysin (Ply), in the pathogenesis of lung and myocardial dysfunction. Topics covered in this review include the burden of pneumococcal disease, risk factors, virulence determinants of the pneumococcus, complications of severe disease, antibiotic and adjuvant therapies, as well as the structure of Ply and the role of the toxin in disease pathogenesis. Given the increasing recognition of the clinical potential of Ply-neutralisation strategies, the remaining sections of the review are focused on updates of the types, benefits and limitations of currently available therapies which may attenuate, directly and/or indirectly, the injurious actions of Ply. These include recently described experimental therapies such as various phytochemicals and lipids, and a second group of more conventional agents the members of which remain the subject of ongoing clinical evaluation. This latter group, which is covered more extensively, encompasses macrolides, statins, corticosteroids, and platelet-targeted therapies, particularly aspirin.

Immunomodulatory effects of pidotimod in adults with community-acquired pneumonia undergoing standard antibiotic therapy

The morbidity and mortality of community-acquired pneumonia (CAP) are still elevated and two aspects seem to contribute to a worse outcome: an uncontrolled inflammatory reaction and an inadequate immune response. Adjuvants, including corticosteroids and intravenous immunoglobulins, have been proposed to counterbalance these effects but their efficacy is only partial. We examined the immunomodulatory activity of Pidotimod (PDT), a synthetic dipeptide molecule in adult patients hospitalized for CAP. Sixteen patients with a diagnosis of CAP and a PSI score III or IV and/or a CURB-65 0-2 were randomized to receive either levofloxacin 500 mg b.i.d. alone or levofloxacin plus PDT (800mg, 2 daily doses). Blood samples were drawn at baseline (T0), before initiation of therapy, as well as 3 (T3), and 5 (T5) days after initiation of therapy. Immunologic and clinical parameters were analyzed at each time point. Supplementation of antibiotic therapy with PDT resulted in an upregulation of antimicrobial and of immunomodulatory proteins as well as in an increased percentage of Toll like receptor (TLR)2- and TLR4, and of CD80- and CD86-expressing immune cells. Notably, Pidotimod supplementation was also associated with a robust reduction of TNFα-producing immune cells. No significant differences were observed in clinical parameters. These results confirm that supplementation of antibiotic therapy with Pidotimod in patients with CAP results in a potentially beneficial modulation of innate immunity.

Fluoroquinolones or macrolides in combination with β-lactams in adult patients hospitalized with community acquired pneumonia: a systematic review and meta-analysis

OBJECTIVE

The best treatment option for hospitalized patients with community-acquired pneumonia (CAP) has not been defined. The effectiveness of β-lactam/fluoroquinolone (BLFQ) versus β-lactam/macrolide (BLM) combinations for the treatment of patients with CAP was evaluated.

METHODS

PubMed, Scopus and the Cochrane Library were searched for observational cohort studies, non-randomized and randomized controlled trials providing data for patients with CAP receiving BLM or BLFQ. Mortality was the primary outcome. A meta-analysis was performed. MINORS and GRADE were used for data quality assessment.

RESULTS

Seventeen studies (16 684 patients) were included. Randomized trials were not identified. A variety of β-lactams, fluoroquinolones and macrolides were used within and between the studies. Mortality was reported at different time points. The available body of evidence had very low quality. In the analysis of unadjusted data, mortality with BLFQ was higher than with BLM (risk ratio 1.33, 95% CI 1.15-1.54, I² 28%). BLFQ was associated with higher mortality regardless of the study design, mortality recording time, study period and study BLM group mortality. BLFQ was associated with higher mortality in American but not European studies. No difference was observed in patients with bacteraemia and septic shock. In the meta-analysis of adjusted mortality data, a non-significant difference between the two regimens was observed (eight studies, adjusted risk ratio 1.26, 95% CI 0.95-1.67, I² 43%).

CONCLUSION

In the absence of data from randomized controlled trials recommendations cannot be made for or against either of the studied regimens in this group of hospitalized patients with CAP. Well designed randomized controlled trials comparing the two regimens are warranted.

Pneumococcal vaccination

PURPOSE OF REVIEW

Pneumococcal diseases (invasive diseases, pneumonia, otitis media, and sinusitis) are among the most frequent preventable infectious diseases carrying a very high morbidity and case fatality rate worldwide. Pneumococcal vaccination is a key element to reduce the global burden of the disease in children and adult population. Our aim is to discuss current knowledge of the epidemiology of pneumococcal disease and pneumococcal vaccines.

RECENT FINDINGS

After the introduction of conjugate vaccines (PCV7 and PCV13), rates of pneumococcal diseases because of vaccine serotypes have decreased considerably among children in the vaccine target and among nonvaccinated children and adults. Results of the Community-Acquired Pneumonia Immunization Trial in Adults demonstrated 45.6% efficacy of PCV13 against the first episode of pneumonia, 45% against first-episode nonbacteremic pneumococcal pneumonia, and 75% against the first episode of invasive pneumococcal diseases in adults older than 65 years. Recommendations for pneumococcal vaccination have changed recently in both the United States and Europe.

SUMMARY

The changing epidemiology of pneumococcal diseases should be closely investigated to assess the effectiveness and the usefulness of the current vaccination policies, and to identify future directions for preventing pneumococcal infections.

New aspects in the management of pneumonia

Despite improvements in the management of community-acquired pneumonia (CAP), morbidity and mortality are still high, especially in patients with more severe disease. Early and appropriate antibiotics remain the cornerstone in the treatment of CAP. However, two aspects seem to contribute to a worse outcome: an uncontrolled inflammatory reaction and an inadequate immune response. Adjuvant treatments, such as corticosteroids and intravenous immunoglobulins, have been proposed to counterbalance these effects. The use of corticosteroids in patients with severe CAP and a strong inflammatory reaction can reduce the time to clinical stability, the risk of treatment failure, and the risk of progression to acute respiratory distress syndrome. The administration of intravenous immunoglobulins seems to reinforce the immune response to the infection in particular in patients with inadequate levels of antibodies and when an enriched IgM preparation has been used; however, more studies are needed to determinate their impact on outcome and to define the population that will receive more benefit.

Epidemiology, virulence factors and management of the pneumococcus

Pneumococcal infections continue to cause significant morbidity and mortality in patients throughout the world. This microorganism remains the most common bacterial cause of community-acquired pneumonia and is associated with a considerable burden of disease and health-care costs in both developed and developing countries. Emerging antibiotic resistance has been a concern because of its potential negative impact on the outcome of patients who receive standard antibiotic therapy. However, there have been substantial changes in the epidemiology of this pathogen in recent years, not least of which has been due to the use of pneumococcal conjugate vaccines in children, with subsequent herd protection in unvaccinated adults and children. Furthermore, much recent research has led to a better understanding of the virulence factors of this pathogen and their role in the pathogenesis of severe pneumococcal disease, including the cardiac complications, as well as the potential role of adjunctive therapy in the management of severely ill cases. This review will describe recent advances in our understanding of the epidemiology, virulence factors, and management of pneumococcal community-acquired pneumonia.

Increased Risk of Acute Kidney Injury following Pneumococcal Pneumonia: A Nationwide Cohort Study

Purpose

Pneumococcal disease leads to renal complications ranging from persistent proteinuria to end-stage renal disease. Studies on the association between pneumococcal pneumonia (PP) and acute kidney injury (AKI) are scant. This study assessed the relationship between PP and risk of AKI.

Methods

This nationwide population-based cohort study examined data from the Taiwan National Health Insurance Research Database for the period 2000–2011. We identified inpatients with newly diagnosed PP according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. In addition, we selected a comparison cohort from inpatient claims without the diagnosis of PP that was randomly frequency-matched with the PP cohort according to age, sex, index year and comorbidities. We analyzed the risks of AKI by using Cox proportional hazards regression models, adjusted for sex, age, and comorbidities.

Results

A total of 10,069 patients with PP and 10,069 controls were enrolled in this study. After adjustments for age, sex, and comorbidities, patients with PP had a 1.11-fold risk of developing AKI compared with the comparison cohort.

Conclusion

This study indicates that AKI risks are higher in patients with PP compared with the comparison cohort. Careful follow-up observation and aggressive treatment are necessary for patients with PP to reduce the risk of AKI.