The ratio of neutrophil-to-lymphocyte and platelet-to-lymphocyte and association with mortality in community-acquired pneumonia: a derivation-validation cohort study

RATIONALE

The ratio of neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR) and platelet-to-lymphocyte (PLR) are biomarkers that have shown potential for predicting mortality in several diseases. For patients hospitalized with community-acquired pneumonia (CAP), the prognostic capabilities of these biomarkers are unknown.

OBJECTIVE

Investigate whether NLR, MLR or PLR were associated with 90-day mortality in CAP. Further, investigate whether the prediction rule CURB-65 could be improved by adding these biomarkers.

METHODS

A derivation-validation study using a Danish multicentre retrospective cohort as the derivation cohort (N = 831) and a European multicentre prospective cohort as the validation cohort (N = 2463). Associations between biomarkers and mortality were assessed using Cox proportional hazard models with adjustments for sex, CURB-65 and comorbidities. A cut-off value for biomarkers was determined using Youden's J Statistics. The performance of CURB-65 with added biomarkers was evaluated using receiver-operating characteristics.

RESULTS

In both cohorts increasing NLR and PLR were associated with 90-day mortality. In the derivation cohort, the hazard ratios for NLR and PLR were 1.016 (95% confidence interval (CI) 1.001-1.032, P = 0.038) and 1.001 (95% CI 1.000-1.001, P = 0.035), respectively. Adding these biomarkers to CURB-65 did not improve its performance.

CONCLUSIONS

NLR and PLR were associated with 90-day mortality in CAP, but did not improve CURB-65.

Bacterial biofilms predominate in both acute and chronic human lung infections

Background

A basic paradigm of human infection is that acute bacterial disease is caused by fast growing planktonic bacteria while chronic infections are caused by slow-growing, aggregated bacteria, a phenomenon known as a biofilm. For lung infections, this paradigm has been thought to be supported by observations of how bacteria proliferate in well-established growth media in the laboratory—the gold standard of microbiology.

Objective

To investigate the bacterial architecture in sputum from patients with acute and chronic lung infections.

Methods

Advanced imaging technology was used for quantification and direct comparison of infection types on fresh sputum samples, thereby directly testing the acute versus chronic paradigm.

Results

In this study, we compared the bacterial lifestyle (planktonic or biofilm), growth rate and inflammatory response of bacteria in freshly collected sputum (n=43) from patient groups presenting with acute or chronic lung infections. We found that both acute and chronic lung infections are dominated by biofilms (aggregates of bacteria within an extracellular matrix), although planktonic cells were observed in both sample types. Bacteria grew faster in sputum from acute infections, but these fast-growing bacteria were enriched in biofilms similar to the architecture thought to be reserved for chronic infections. Cellular inflammation in the lungs was also similar across patient groups, but systemic inflammatory markers were only elevated in acute infections.

Conclusions

Our findings indicate that the current paradigm of equating planktonic with acute and biofilm with chronic infection needs to be revisited as the difference lies primarily in metabolic rates, not bacterial architecture.

Do-not-resuscitate orders in patients with community-acquired pneumonia: a retrospective study

Background

To investigate the use of do-not-resuscitate (DNR) orders in patients hospitalized with community-acquired pneumonia (CAP) and the association with mortality.

Methods

We assembled a cohort of 1317 adults hospitalized with radiographically confirmed CAP in three Danish hospitals. Patients were grouped into no DNR order, early DNR order (≤48 h after admission), and late DNR order (> 48 h after admission). We tested for associations between a DNR order and mortality using a cox proportional hazard model adjusted for patient and disease related factors.

Results

Among 1317 patients 177 (13%) patients received a DNR order: 107 (8%) early and 70 (5%) late, during admission. Patients with a DNR order were older (82 years vs. 70 years, p < 0.001), more frequently nursing home residents (41% vs. 6%, p < 0.001) and had more comorbidities (one or more comorbidities: 73% vs. 59%, p < 0.001). The 30-day mortality was 62% and 4% in patients with and without a DNR order, respectively. DNR orders were associated with increased risk of 30-day mortality after adjustment for age, nursing home residency and comorbidities. The association was modified by the CURB-65 score Hazard ratio (HR) 39.3 (95% CI 13.9–110.6), HR 24.0 (95% CI 11.9–48,3) and HR 9.4 (95% CI: 4.7–18.6) for CURB-65 score 0–1, 2 and 3–5, respectively.

Conclusion

In this representative Danish cohort, 13% of patients hospitalized with CAP received a DNR order. DNR orders were associated with higher mortality after adjustment for clinical risk factors. Thus, we encourage researcher to take DNR orders into account as potential confounder when reporting CAP associated mortality.

Is chronic obstructive pulmonary disease a risk factor for death in patients with community acquired pneumonia?

BACKGROUND

It is still a matter of debate whether the outcome of community acquired pneumonia is more severe in patients with chronic obstructive pulmonary disease. We aimed to determine whether chronic obstructive pulmonary disease was associated with increased mortality and to identify risk-factors for mortality in patients with community acquired pneumonia and chronic obstructive pulmonary disease.

METHODS

Retrospective cohort study comparing patients with community acquired pneumonia and chronic obstructive pulmonary disease to patients without chronic obstructive pulmonary disease. We included 1309 patients with community acquired pneumonia admitted from 2011 until 2012 (243 patients with chronic obstructive pulmonary disease and 1066 without chronic obstructive pulmonary disease).

RESULTS

At admission patients with community acquired pneumonia and chronic obstructive pulmonary disease presented with more severe pneumonia as measured by CURB-65 score compared to patients without chronic obstructive pulmonary disease. Mortality on day 30 was generally high, and higher among patients with community acquired pneumonia and chronic obstructive pulmonary disease compared to those without chronic obstructive pulmonary disease (16.0% versus 11.3%, p = .04). In an adjusted analysis, however, chronic obstructive pulmonary disease was not independently associated with 30-d mortality (odds ratio 0.94, confidence interval 95% 0.59-1.50). Factors related to mortality in patients with community acquired pneumonia and chronic obstructive pulmonary disease were age, premorbid condition, severity of pneumonia as determined by CURB-65 score, and pleural effusion and multi-lobular infiltrate on chest X-ray.

CONCLUSIONS

Chronic obstructive pulmonary disease was not independently associated with 30-d mortality in patients with community acquired pneumonia.

Undiagnosed Diabetes Mellitus in Community-Acquired Pneumonia: A Prospective Cohort Study

Background

Diabetes mellitus is an important risk factor for community-acquired pneumonia, whereas the prevalence of undiagnosed diabetes mellitus and prediabetes in patients with community-acquired pneumonia is largely unknown. We aimed to determine the prevalence of prediabetes, undiagnosed diabetes mellitus, and risk factors associated with undiagnosed diabetes mellitus in a large European community-acquired pneumonia cohort.

Methods

This was a multicenter prospective cohort study of hospitals and private practices in Germany and Austria encompassing 1961 adults with community-acquired pneumonia included in the German Community-Acquired Pneumonia Competence Network (CAPNETZ) study between 2007 and 2014. The prevalence of undiagnosed diabetes mellitus and prediabetes was estimated based on hemoglobin A1c measurements. Logistic regression was used to assess risk factors for undiagnosed diabetes mellitus.

Results

Fifteen percent of patients had known diabetes mellitus. Among patients without known diabetes mellitus, 5.0% had undiagnosed diabetes mellitus and 37.5% had prediabetes. Male sex (odds ratio [OR], 2.45 [95% confidence interval {CI}, 1.35-4.45]), body mass index ≥25 kg/m2 (OR, 2.64 [95% CI, 1.48-4.72]), and hyperglycemia at admission (6-11 mM: OR, 2.93 [95% CI, 1.54-5.60] and ≥11 mM: OR, 44.76 [95% CI, 17.58-113.98]) were associated with undiagnosed diabetes mellitus. Patients with undiagnosed diabetes mellitus had a higher 180-day mortality rate compared to patients without diabetes mellitus (12.1% vs 3.8%, respectively; P = .001).

Conclusions

Undiagnosed diabetes mellitus was prevalent among community-acquired pneumonia. Male sex, overweight, and hyperglycemia at admission were associated with undiagnosed diabetes mellitus. The long-term mortality among patients with undiagnosed diabetes mellitus was high compared to patients without diabetes mellitus.

Associations between biomarkers at discharge and co-morbidities and risk of readmission after community-acquired pneumonia: a retrospective cohort study

To investigate whether hemoglobin, white blood cell count (WBC), urea, sodium, albumin, and C-reactive protein at discharge in patients hospitalized for community-acquired pneumonia (CAP) are associated with 30-day readmission. This study is a retrospective cohort study, which included all adult patients discharged after hospitalization for CAP from three Danish hospitals between January 2011 and July 2012. The outcome was all-cause, unplanned, 30-day readmission. Biomarker concentrations at discharge were transformed into binary variables by using either upper or lower quartiles as cut-off; the upper quartile was used for WBC, urea, and C-reactive protein, and the lower quartile was used for hemoglobin, sodium, and albumin. The study population consisted of 1149 patients. One hundred eighty-four (16.0%) patients were readmitted. Independent risk factors of readmission were WBC ≥ 10.6 cells × 10⁹/L (hazard ratio 1.50; 95% CI, 1.07–2.11) and albumin <32 g/L (hazard ratio 1.78; 95% CI, 1.24–2.54) at discharge and the presence of ≥ 2 co-morbidities (hazard ratio 1.74; 95% CI, 1.15–2.64). When WBC, albumin, and co-morbidities were combined into a risk-stratification tool, there was a step-wise increase in risk of readmission for patients with 1, 2, or 3 risk factors with hazard ratios of 1.76 (95% CI, 1.25–2.49), 2.59 (95% CI, 1.71–3.93), and 6.15 (95% CI 3.33–11.38), respectively. WBC ≥ 10.6 cells × 10⁹/L and albumin < 32 g/L at discharge and the presence of ≥ 2 co-morbidities were independently associated with increased risk of 30-day readmission.

The impact of blood glucose on community-acquired pneumonia: a retrospective cohort study

Hyperglycaemia is common in patients with community-acquired pneumonia (CAP) and is a predictor of severe outcomes. Data are scarce regarding whether this association is affected by diabetes mellitus (DM) and also regarding its importance for severe outcomes in hospital. We determined the impact of blood glucose on severe outcomes of CAP in hospital. We studied 1318 adult CAP patients hospitalised at three Danish hospitals. The association between blood glucose and DM status and severe clinical outcome (admission to an intensive care unit (ICU) and/or in-hospital mortality) was assessed by logistic regression. Models were adjusted for CURB-65 score and comorbidities. 12% of patients had DM. In patients without DM an increase in admission blood glucose was associated with risk for ICU admittance (OR 1.25, 95% CI 1.13-1.39), but not significantly associated with in-hospital mortality (OR 1.10, 95% CI 0.99-1.23). In patients with DM an increase in admission blood glucose was not associated with ICU admittance (OR 1.05, 95% CI 1.00-1.12) or in-hospital mortality (OR 1.05, 95% CI 0.99-1.12). An increase in admission blood glucose (only in patients without DM) was associated with a higher risk for ICU admittance and a trend towards higher in-hospital mortality. DM was not associated with a more severe outcome of CAP.

Cerebrospinal fluid pleocytosis in infectious and noninfectious central nervous system disease: A retrospective cohort study

Cerebrospinal fluid (CSF) analysis is the most important tool for assessing central nervous system (CNS) disease. An elevated CSF leukocyte count rarely provides the final diagnosis, but is almost always an indicator of inflammation within the CNS.The present study investigated the variety of diseases associated with CSF pleocytosis.CSF analyses were identified through the biochemical database used in the capital region of Denmark in the period from 2003 to 2010. In patients >15 years, clinical diagnoses associated with the finding of a CSF leukocyte count >10 × 10 cells/L were obtained from discharge records and patient files.A total of 1058 CSF samples from 1054 patients were included in the analysis. The median age was 50 (interquartile range: 36-67) and 53% were male. Eighty-one different diagnoses were identified in 1058 cases with an elevated CSF leukocyte count, besides unknown causes. Infections were the most common cause of CSF pleocytosis (61.4%) followed by miscellaneous causes (12.7%), vascular (9.7%), neurodegenerative (7%), neoplastic (5%), and inflammatory conditions (4.2%). Only infections presented with leukocyte counts >10,000 × 10/L. Infections represented 82.6% of all cases with a leukocyte count >100 × 10/L whereas 56.3% of cases with at leukocyte counts <100 × 10/L were dominated by disease not related to infection.The present study may serve as a reminder to clinicians of what diseases and disease categories to suspect when patients present with CSF biochemistry indicating CNS inflammation.

Penicillin treatment for patients with Community-Acquired Pneumonia in Denmark: a retrospective cohort study

BACKGROUND

Community-acquired pneumonia (CAP) is a severe infection, with high mortality. Antibiotic strategies for CAP differ across Europe. The objective of the study was to describe the epidemiology of CAP in Denmark and evaluate the prognosis of patients empirically treated with penicillin-G/V monotherapy.

METHODS

Retrospective cohort study including hospitalized patients with x-ray confirmed CAP. We calculated the population-based incidence, reviewed types of empiric antibiotics and duration of antibiotic treatment. We evaluated the association between mortality and treatment with empiric penicillin-G/V using logistic regression analysis.

RESULTS

We included 1320 patients. The incidence of hospitalized CAP was 3.1/1000 inhabitants. Median age was 71 years (IQR; 58-81) and in-hospital mortality was 8%. Median duration of antibiotic treatment was 10 days (IQR; 8-12). In total 45% were treated with penicillin-G/V as empiric monotherapy and they did not have a higher mortality compared to patients treated with broader-spectrum antibiotics (OR 0.92, CI 95% 0.55-1.53).

CONCLUSION

The duration of treatment exceeded recommendations in European guidelines. Empiric monotherapy with penicillin-G/V was commonly used and not associated with increased mortality in patients with mild to moderate pneumonia. Our results are in agreement with current conservative antibiotic strategy as outlined in the Danish guidelines.