A predictive model for the treatment approach to community-acquired pneumonia in patients needing ICU admission

Effects of the second dose of COVID-19 vaccines in patients with autoimmune rheumatic diseases with hybrid immunity

Patients with autoimmune rheumatic diseases with a previous infection by the SARS-CoV-2 virus have exaggerated responses to a single dose of COVID-19 vaccination as compared to fully vaccinated infection naive patients. The second dose is currently recommended at an extended gap after the infection, but the information available regarding response to the second dose in this subgroup is limited. Patients with AIRDs previously infected with COVID-19, who have received at least one dose of AZD1222/ChAdOx1 (n = 200) were included and stratified based on vaccine doses (V), and infection (I) into I + V, I + V + V, V + I, V + V + I. Anti-RBD (receptor binding domain) antibodies were compared across the four groups. In 49 patients of the I + V + V group (AZD12222), paired sera were compared for antibody levels and neutralization after each vaccine dose. Thirty patients with hybrid immunity after BBV152 and 25 with complete vaccination without infection were included as controls. The highest anti-RBD antibody levels were observed in the V + V + I group (18,219 ± 7702 IU/ml) with statistically similar titers in the I + V + V (10,392 ± 8514 IU/ml) and the I + V (8801 ± 8122 IU/ml). This was confirmed in the 49 paired samples that paradoxically showed a lowering of antibody titers after the second dose [9626 (IQR: 4575-18,785)-5781 (2484-11,906); p < 0.001]. Neutralization of the Delta variant was unaffected but Omicron neutralization was significantly reduced after the second dose [45.7 (5.3-86.53)-35% (7.3-70.9); p = 0.028]. Ancillary analyses showed that only the hybrid immune sera could neutralize the Omicron variant and AZD1222 hybrids performed better than BBV152 hybrids. The second dose of AZD1222 did not boost antibody titers in patients with RD who had COVID-19 previously. In the analysis of paired sera, the second dose led to a statistically significant reduction in antibody titers and also reduced neutralization of the Omicron variant.

Paediatrics: how to manage septic shock

Background

Septic shock is a common critical illness associated with high morbidity and mortality in children. This article provides an updated narrative review on the management of septic shock in paediatric practice.

Methods

A PubMed search was performed using the following Medical Subject Headings: "sepsis", "septic shock" and "systemic inflammatory response syndrome". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies and reviews. The search was limited to the English literature and specific to children.

Results

Septic shock is associated with high mortality and morbidity. The outcome can be improved if the diagnosis is made promptly and treatment initiated without delay. Early treatment with antimicrobial therapy, fluid therapy and vasoactive medications, and rapid recognition of the source of sepsis and control are the key recommendations from paediatric sepsis management guidelines.

Conclusion

Most of the current paediatric sepsis guideline recommendations are based on the adult population; therefore, the research gaps in paediatric sepsis management should be addressed.

Typical or atypical pneumonia and severe acute respiratory symptoms in PICU

Background and Aims

Mycoplasma pneumoniae (MP) is a common childhood pathogen associated with atypical pneumonia (AP). It is often a mild disease and seldom results in paediatric intensive care (PICU) admission. In 2003, World Health Organization (WHO) coined the word SARS (severe acute respiratory syndrome) in patients with severe acute respiratory symptoms (sars) for an outbreak of AP in Hong Kong due to a novel coronavirus. In 2012, another outbreak of coronavirus AP occurred in the Middle East. Confusing case definitions such as MERS (Middle East respiratory syndrome) and SARI (severe acute respiratory infections) were coined. This paper aims to present a case of MP with sars, ARDS, pneumonia and pleural effusion during the MERS epidemics, and review the incidence and mortality of severe AP with MP.

Methods

We presented a case of MP with sars, acute respiratory distress syndrome (ARDS), pneumonia and pleural effusion during the MERS epidemics, and performed a literature review on the incidence and mortality of severe AP with MP requiring PICU care.

Results

In early 2013, an 11‐year‐old girl presented with sars, ARDS (acute respiratory distress syndrome), right‐sided pneumonia and pleural effusion. She was treated with multiple antibiotics. Streptococcus pneumoniae was not isolated in this girl with ‘typical’ pneumonia by symptomatology and chest radiography, but tracheal aspirate identified MP instead. The respiratory equations are computed with PaO₂/FiO₂ consistent with severe lung injury. Literature on the incidence and mortality of severe AP with MP requiring PICU care is reviewed. Six, 165 and 293 articles were found when PubMed (a service of the U.S. National Library of Medicine) was searched for the terms ‘mycoplasma’ and ‘ICU’, ‘mycoplasma’ and ‘mortality’, and ‘mycoplasma' and ‘severe’. Mortality and PICU admission associated with MP is general low and rarely reported. Experimental and clinical studies have suggested that the pathogenesis of lung injuries in MP infection is associated with a cell‐mediated immune reaction, and high responsiveness to corticosteroid therapy has been reported especially for severe disease. Management of severe mycoplasma infection in the PICU includes general cardiopulmonary support and specific antimicrobial treatment. Macrolide resistance genotypes have been detected.

Conclusion

We urge health organizations to refrain from the temptation of coining unnecessary new terminology to describe essentially the same conditions each and every time when outbreaks of AP occur.

Patients with community acquired pneumonia admitted to European intensive care units: an epidemiological survey of the GenOSept cohort

Introduction

Community acquired pneumonia (CAP) is the most common infectious reason for admission to the Intensive Care Unit (ICU). The GenOSept study was designed to determine genetic influences on sepsis outcome. Phenotypic data was recorded using a robust clinical database allowing a contemporary analysis of the clinical characteristics, microbiology, outcomes and independent risk factors in patients with severe CAP admitted to ICUs across Europe.

Methods

Kaplan-Meier analysis was used to determine mortality rates. A Cox Proportional Hazards (PH) model was used to identify variables independently associated with 28-day and six-month mortality.

Results

Data from 1166 patients admitted to 102 centres across 17 countries was extracted. Median age was 64 years, 62% were male. Mortality rate at 28 days was 17%, rising to 27% at six months. Streptococcus pneumoniae was the commonest organism isolated (28% of cases) with no organism identified in 36%. Independent risk factors associated with an increased risk of death at six months included APACHE II score (hazard ratio, HR, 1.03; confidence interval, CI, 1.01-1.05), bilateral pulmonary infiltrates (HR1.44; CI 1.11-1.87) and ventilator support (HR 3.04; CI 1.64-5.62). Haematocrit, pH and urine volume on day one were all associated with a worse outcome.

Conclusions

The mortality rate in patients with severe CAP admitted to European ICUs was 27% at six months. Streptococcus pneumoniae was the commonest organism isolated. In many cases the infecting organism was not identified. Ventilator support, the presence of diffuse pulmonary infiltrates, lower haematocrit, urine volume and pH on admission were independent predictors of a worse outcome.

Optimizing Treatment Outcomes in Severe Community-Acquired Pneumonia

Severe community-acquired pneumonia (CAP) is a life-threatening condition that requires intensive care unit (ICU) admission. Clinical presentation is characterized by the presence of respiratory failure, severe sepsis, or septic shock. Severe CAP accounts for approximately 5-35% of hospital-treated cases of pneumonia with the majority of patients having underlying comorbidities. The most common pathogens associated with this disease are Streptococcus pneumoniae, Legionella spp., Haemophilus influenzae, and Gram-negative enteric rods. Microbial investigation is probably helpful in the individual case but is likely to be more useful for defining local antimicrobial policies. The early and rapid initiation of empiric antimicrobial treatment is critical for a favorable outcome. It should include intravenous beta-lactam along with either a macrolide or a fluoroquinolone. Modifications of this basic regimen should be considered in the presence of distinct comorbid conditions and risk factors for specific pathogens. Other promising nonantimicrobial new therapies are currently being investigated. The assessment of severity of CAP helps physicians to identify patients who could be managed safely in an ambulatory setting. It may also play a crucial role in decisions about length of hospital stay and time of switching to oral antimicrobial therapy in different groups at risk. The most important adverse prognostic factors include advancing age, male sex, poor health of patient, acute respiratory failure, severe sepsis, septic shock, progressive radiographic course, bacteremia, signs of disease progression within the first 48-72 hours, and the presence of several different pathogens such as S. pneumoniae, Staphylococcus aureus, Gram-negative enteric bacilli, or Pseudomonas aeruginosa. However, some important topics of severity assessment remain controversial, including the definition of severe CAP. Prediction rules for complications or death from CAP, although far from perfect, should identify the majority of patients with severe CAP and be used to support decision-making by the physician. They may also contribute to the evaluation of processes and outcomes of care for patients with CAP.

Guidelines for the management of adult lower respiratory tract infections--summary

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Guidelines for the management of adult lower respiratory tract infections--full version

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. Background sections and graded evidence tables are also included. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Streptococcus pneumoniae and Legionella pneumophila pneumonia in HIV-infected patients

We compared the epidemiological data, clinical features and mortality of community-acquired pneumonia (CAP) by Streptococcus pneumoniae and Legionella in HIV-infected patients and determined discriminative features. An observational, comparative study was performed (January 1994 to December 2004) in 15 HIV patients with CAP by Legionella and 46 by S. pneumoniae. No significant differences were observed in delay until initiation of appropriate antibiotic therapy. Smoking, cancer and chemotherapy were more frequent in patients with Legionella pneumonia (p=0.03, p=0.00009 and p=0.01). Patients with Legionella pneumonia had a higher mean CD4 count (p=0.04), undetectable viral load (p=0.01) and received highly active antiretroviral therapy more frequently (p=0.004). AIDS was more frequent in patients with S. pneumoniae pneumonia (p=0.03). Legionella pneumonia was more severe (p=0.007). Extrarespiratory symptoms, hyponatraemia and increased creatine phosphokinase were more frequent in Legionella pneumonia (p=0.02, p=0.002 and p=0.006). Respiratory failure, need for ventilation and bilateral chest X-ray involvement were of note in the Legionella group (p=0.003, p=0.002 and p=0.002). Mortality tended to be higher in the Legionella group (6.7 vs 2.2%). In conclusion, CAP by Legionella has a higher morbimortality than CAP by S. pneumoniae in HIV-infected patients. Detailed analysis of CAP presentation features allows suspicion of Legionnaires' disease in this subset.

Severe community-acquired pneumonia: approach to therapy

Despite substantial progress in therapeutic options, severe community-acquired pneumonia (CAP) remains a significant cause of morbidity and mortality worldwide. Recognising the clinical importance of CAP over the past several years, different medical societies and health organisations in different countries have proposed specific guidelines for the management of CAP. Early and rapid initiation of antimicrobial therapy has been advocated for a favourable outcome. Treatment is empirical as the diagnostic yield for potential pathogens does not exceed 50%. Dual therapy is emerging as the preferred therapy for severe CAP. The regimen is based on an epidemiological approach with emphasis on covering both typical and atypical pathogens. Non-antimicrobial adjuvant therapies including non-invasive ventilation and immunomodulatory agents are emerging as promising area for future development.

Evaluation of the Binax NOW Streptococcus pneumoniae urinary antigen assay in intensive care patients hospitalized for pneumonia

OBJECTIVE

To evaluate the diagnostic performance of Binax Now S. pneumoniae urinary antigen rapid immunochromatographic membrane test (ICT) for patients with suspicion of community-acquired pneumonia hospitalized in intensive care and to assess the impact of prior antibiotics on its diagnostic performance.

DESIGN AND SETTING

Retrospective study in a medicosurgical ICU in a 700-bed general hospital.

PATIENTS

Charts of patients with ICT performed (result blinded) were reviewed between May 2002 and July 2004. ICT has been performed in 140 of the 1,006 patients hospitalized in the unit; two-thirds had received antibiotics prior to admission.

MEASUREMENTS AND RESULTS

Diagnosis of pneumonia was made according to usual criteria. All patients had at least one microbiological test. Pneumonia diagnosis confirmed in 108 patients including 32 pneumococcal. ICT was positive in 23 of 32 patients with pneumococcal pneumonia, in 11 of 108 without, and in none of the 32 patients without pneumonia, resulting in sensitivity, specificity, and positive and negative predictive values of, respectively: 72%, 90%, 68% and 92%. Positive likelihood ratios were comparable among patients with or without prior antibiotics (respectively 6 and 12 for 7 in the overall population).

CONCLUSIONS

This first clinical evaluation of ICT in intensive care patients hospitalized for suspicion of community-acquired pneumonia, demonstrated performance in accordance with published data even in the case of prior antibiotics. Its clinical interest and impact on antibiotics policy remain to be refined.

Clonal and Capsular Types Decide Whether Pneumococci Will Act as a Primary or Opportunistic Pathogen

BACKGROUND

Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide. The role of the different capsular and clonal types in invasive disease severity remains to be defined.

METHODS

Disease severity and disease type were correlated to age, underlying disease, capsular serotype, and clonal type of the causative agent for 494 adult patients with invasive pneumococcal disease.

RESULTS

Pneumococcal isolates of serotypes 1 and 7F were genetically homogenous, had the highest potential to infect previously healthy individuals, and were not causing deaths. Also, type 1 isolates were only found among younger adults, whereas other serotypes were mainly found among elderly persons (e.g., type 23F). Some serotypes and/or clones were more prone to cause more-severe disease, as observed by high APACHE II scores calculated at admission, and were also associated with a high mortality (e.g., clones of type 3 and 11A). We found no evidence of an impact of penicillin resistance on disease severity and disease type.

CONCLUSIONS

We suggest that clones with capsular types 1 and 7F, which are known to have a high invasive disease potential, behave as primary pathogens, whereas clones with other capsular types with a lower relative risk of causing invasive disease are more opportunistic, primarily affecting patients with underlying disease. Disease caused by the latter group, however, was more severe, even in previously healthy individuals.

Severe community-acquired pneumonia in an intensive care unit: risk factors for mortality

OBJECTIVE

To evaluate severe community-acquired pneumonia (SCAP) patients in an intensive care unit (ICU) with regard to risk factors for mortality and to compare ICU patients with matched non-ICU patients to evaluate whether our judgement for ICU admission was appropriate or not.

MATERIALS AND METHODS

During a 7-year period, all patients with CAP who were admitted to the ICU were examined. They underwent clinical and radiographic evaluations, and two commonly used severity of illness scores were also calculated using the Simplified Acute Physiological Score (SAPS) and the Acute Physiology and Chronic Health Evaluation (APACHE) II methods. To detect risk factors for ICU admission using existing guidelines, each study patient was matched with two patients hospitalized in a general medical ward.

RESULTS

Seventy-two patients were identified during the study period. Their mean age was 72.9 years, and 35 patients (48.6%) subsequently died. For the univariate analysis, there were significant differences with the pulse rate > or = 130/min, blood urea nitrogen > or = 30 mg/dl, multilobar shadow, SAPS > or = 13, APACHE II > or = 23, and the occurrence of septic shock between the survivors and those who died. For the multivariate analysis, septic shock (p = 0.0005, odds ratio of 26.6) and blood urea nitrogen > or = 30 mg/dl (p = 0.037, odds ratio of 5.38) were associated with mortality. Regarding the characteristics of different clinical predictions for ICU admission, the revised American Thoracic Society criteria might have been the most accurate.

CONCLUSION

Septic shock was associated with high mortality, which is a more accurate and higher predictor of mortality than was physical examination, laboratory or radiographic findings.

[Guidelines for the management of community pneumonia in adult who needs hospitalization]

Community acquired pneumonia is still an important health problem. In Spain the year incidence is 162 cases per 100,000 inhabitants with 53,000 hospital admission costing 115 millions of euros per year. In the last years there have been significant advances in the knowledge of: aetiology, diagnostic tools, treatment alternatives and antibiotic resistance. The Spanish Societies of Intensive and Critical Care (SEMICYUC), Infectious Diseases and Clinical Microbiology (SEIMC) and Pulmonology and Thoracic Surgery (SEPAR) have produced these evidence-based Guidelines for the management of community acquired pneumonia in Adults. The main objective is to help physicians to make decisions about this disease. The different points that have been developed are: aetiology, diagnosis, treatment and prevention.

Impact of adequate empirical antibiotic therapy on the outcome of patients admitted to the intensive care unit with sepsis

OBJECTIVES

Our primary goal was to evaluate the impact on in-hospital mortality rate of adequate empirical antibiotic therapy, after controlling for confounding variables, in a cohort of patients admitted to the intensive care unit (ICU) with sepsis. The impact of adequate empirical antibiotic therapy on early (<3 days), 28-day, and 60-day mortality rates also was assessed. We determined the risk factors for inadequate empirical antibiotic therapy. DESIGN Prospective cohort study.

SETTING

ICU of a tertiary hospital.

PATIENTS

All the patients meeting criteria for sepsis at admission to the ICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Four hundred and six patients were included. Microbiological documentation of sepsis was obtained in 67% of the patients. At ICU admission, sepsis was present in 105 patients (25.9%), severe sepsis in 116 (28.6%), and septic shock in 185 (45.6%). By multivariate analysis, predictors of in-hospital mortality were Sepsis-related Organ Failure Assessment (SOFA) score at ICU admission (odds ratio [OR], 1.29; 95% confidence interval [CI], 1.19-1.40), the increase in SOFA score over the first 3 days in the ICU (OR, 1.40; 95% CI, 1.19-1.65), respiratory failure within the first 24 hrs in the ICU (OR, 3.12; 95% CI, 1.54-6.33), and inadequate empirical antimicrobial therapy in patients with "nonsurgical sepsis" (OR, 8.14; 95% CI, 1.98-33.5), whereas adequate empirical antimicrobial therapy in "surgical sepsis" (OR, 0.37; 95% CI, 0.18-0.77) and urologic sepsis (OR, 0.14; 95% CI, 0.05-0.41) was a protective factor. Regarding early mortality (<3 days), factors associated with fatality were immunosuppression (OR, 4.57; 95% CI, 1.69-13.87), chronic cardiac failure (OR, 9.83; 95% CI, 1.98-48.69) renal failure within the first 24 hrs in the unit (OR, 8.63; 95% CI, 3.31-22.46), and respiratory failure within the first 24 hrs in the ICU (OR, 12.35; 95% CI, 4.50-33.85). Fungal infection (OR, 47.32; 95% CI, 5.56-200.97) and previous antibiotic therapy within the last month (OR, 2.23; 95% CI, 1.1-5.45) were independent variables related to administration of inadequate antibiotic therapy.

CONCLUSIONS

In patients admitted to the ICU for sepsis, the adequacy of initial empirical antimicrobial treatment is crucial in terms of outcome, although early mortality rate was unaffected by the appropriateness of empirical antibiotic therapy.

[Respiratory infections outside the hospital. DIRA study]

INTRODUCTION

Most visits to the primary care center are for infection and particularly respiratory tract infection. Antimicrobial administration for these clinical processes is common and these agents are often used to treat viral infections. La Fundación para el Estudio de la Infección (Foundation for the Study of Infection) designed the DIRA (Día de la Infección Respiratoria del Adulto, Adult Respiratory Infection Day) Project to investigate and assess the impact of this problem.

METHODS

The study design consisted of one-day cross sections with the participation of 720 physicians belonging to Primary Health Care Centers from the 17 Autonomic Regions of Spain, establishing a one-day cross section every three months for one year. Epidemiologic, clinical and therapeutic factors were evaluated.

RESULTS

The total number of visits attended was 72 929, and 14 426 patients had infectious processes (43.9%). Among these, 9145 (63.4%) had a respiratory infection. The mean age of the patients was 44.6 years and 34.1% had an underlying condition. Common cold was the most frequent diagnosis. Antibiotics were prescribed in 53.2% of patients. Results were compared to those of a previous study.

DISCUSSION

Infection in general and respiratory infection in particular is frequently attended in primary care. Antibiotics are widely used in our setting and self-medication is common.

The role of atypical pathogens in community-acquired pneumonia

The atypical pathogens in community-acquired pneumonia traditionally have included Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella spp. Recent studies documenting their epidemiology and clinical characteristics have shown that these organisms are indistinguishable from the pneumococcus. Furthermore, therapy no longer depends on the specific bacterial cause of community-acquired pneumonia. Etiologic diagnosis is still difficult, although new methods are becoming available. This article focuses on these issues and on why the term atypical is no longer meaningful.

Evaluation of the Winthrop-University Hospital criteria to identify Legionella pneumonia

STUDY OBJECTIVE

To measure the ability of a set of clinical parameters, the Winthrop-University Hospital (WUH) criteria, to identify Legionella pneumonia while discriminating against bacteremic pneumococcal pneumonia at the time of hospitalization for community-acquired pneumonia (CAP).

DESIGN

Retrospective case-control study.

SETTING

An urban county hospital and a tertiary-care Veterans Affairs hospital.

PATIENTS

Thirty-seven patients with Legionella pneumonia (diagnosed by a positive result of a urinary Legionella antigen test) and 31 patients with bacteremic pneumococcal pneumonia. A subgroup of patients with all required laboratory criteria were studied further.

RESULTS

The WUH criteria correctly identified 29 of 37 patients with Legionella pneumonia (sensitivity, 78%; 95% confidence interval [CI], 61 to 90%), while successfully excluding legionellosis in 20 of 31 patients with bacteremic pneumococcal pneumonia (specificity, 65%; 95% CI, 45 to 80%). The positive and negative predictive values, adjusted for a relative prevalence of 1:3 between Legionella and Streptococcus pneumoniae bacteremia, were 42% (95% CI, 25 to 61%) and 90% (95% CI, 74 to 97%), respectively. In the subgroup analysis, the WUH criteria were successful in identifying 20 of 23 patients with Legionella pneumonia (sensitivity, 87%; 95% CI, 65 to 97%), while excluding legionellosis in 9 of 18 patients with bacteremic pneumococcal pneumonia (specificity, 50%; 95% CI, 27 to 73%). The adjusted positive and negative predictive values for a 1:3 relative prevalence were 37% (95% CI, 20 to 59%) and 92% (95% CI, 62 to 98%), respectively. The predictive values were changed in the directions expected for an increased relative prevalence of 1:1. The areas under the receiver operating characteristic curves were 0.72 +/- 0.06 for the entire study group and 0.68 +/- 0.09 for the subgroup.

CONCLUSIONS

Although the WUH criteria discriminated fairly well between cases (mean +/- SE) and control subjects, the sensitivity is not high enough to exclude legionellosis confidently. These results suggest that empiric therapy for Legionella pneumonia should be included in the initial antibiotic regimen for hospitalized patients with CAP.

Summary of Canadian guidelines for the initial management of community-acquired pneumonia: an evidence-based update by the Canadian Infectious Disease Society and the Canadian Thoracic Society

Community-acquired pneumonia (CAP) is a serious illness with a significant impact on individual patients and society as a whole. Over the past several years, there have been significant advances in the knowledge and understanding of the etiology of the disease, and an appreciation of problems such as mixed infections and increasing antimicrobial resistance. The development of additional fluoroquinolone agents with enhanced activity against Streptococcus pneumoniae has been important as well.It was decided that the time had come to update and modify the previous CAP guidelines, which were published in 1993. The current guidelines represent a joint effort by the Canadian Infectious Diseases Society and the Canadian Thoracic Society, and they address the etiology, diagnosis and initial management of CAP. The diagnostic section is based on the site of care, and the treatment section is organized according to whether one is dealing with outpatients, inpatients or nursing home patients.

Severe community-acquired pneumonia. Risk factors and follow-up epidemiology

The aim of the study was to determine risk factors for severe community-acquired pneumonia (CAP) as well as to compare microbial patterns of severe CAP to a previous study from our respiratory intensive care unit (ICU) originating from 1984 to 1987. Patients admitted to the ICU according to clinical judgment were defined as having severe CAP. For the study of risk factors, a hospital-based case-control design was used, matching each patient with severe CAP to a patient hospitalized with CAP but not requiring ICU admission. Microbial investigation included noninvasive and invasive techniques. Overall, 89 patients with severe CAP were successfully matched to a control patient. The presence of an alcohol ingestion of >/= 80 g/d (odds ratio [OR] 3.9, 95% confidence interval [CI] 1.4 to 10.6, p = 0.008) was found to be an independent risk factor for severe CAP and prior ambulatory antimicrobial treatment (OR 0.37, 95% CI 0.17 to 0.79, p = 0.009) to be protective. Streptococcus pneumoniae (24%) continued to be the most frequent pathogen; however, 48% of strains were drug-resistant. "Atypical" bacterial pathogens were significantly more common (17% versus 6%, p = 0.006) and Legionella spp. less common (2% versus 14%, p = 0.004) than in our previous study, whereas gram-negative enteric bacilli (GNEB) and Pseudomonas aeruginosa continued to represent important pathogens (6% and 5%, respectively). Our findings provide additional evidence for the importance of the initiation of early empiric antimicrobial treatment for a favorable outcome of CAP. Variations of microbial patterns are only in part due to different epidemiological settings. Therefore, initial empiric antimicrobial treatment will also have to take into account local trends of changing microbial patterns.

Severe community-acquired pneumonia

Severe CAP is a life-threatening condition defined by the presence of respiratory failure or symptoms of severe sepsis or septic shock. It accounts for approximately 10% of hospitalized patients with CAP. The majority of patients with severe pneumonia have underlying comorbid illnesses, with COPD, alcoholism, chronic heart disease, and diabetes mellitus being the most frequent. S. pneumoniae, Legionella spp, GNEB (especially K. pneumoniae), H. influenzae, S. aureus/spp, Mycoplasma pneumoniae, respiratory viruses (especially influenza viruses), and P. aeruginosa represent the most important causative organisms of severe CAP. Rapid initiation of appropriate antimicrobial treatment is crucial for a favorable outcome. Initial antimicrobial treatment should be based on an epidemiological (empiric) approach. Microbial investigation may be helpful in the individual case but is probably more useful to define local antimicrobial policies based on local epidemiologic and susceptibility patterns. Mortality rates range from 21% to 54%. The most important prognostic factors include general health state of the patient, appropriateness of initial antimicrobial treatment, and the existence of bacteremia, as well as factors reflecting severe respiratory failure, severe sepsis, septic hypotension or shock, and the extent of infiltrates in chest radiograph. Initial antimicrobial treatment should consist of a second (or third) generation cephalosporin and erythromycin. Modifications of this basic regimen should be considered in the presence of distinct comorbid conditions and risk factors for distinct pathogens. Promising new approaches of nonantimicrobial treatment, including noninvasive ventilation, treatment of hypoxemia, and immunomodulation, are under investigation.

Atypical pathogens in community-acquired pneumonia

The atypical pathogens are an important and significant cause of CAP. The clinical and radiologic manifestations of CAP caused by these pathogens are modulated by the immunologic and physiologic status of the host, and therefore are not pathogen-specific. The range of frequencies found in various studies for the atypical pathogens among the causes of CAP is broad. These frequencies are affected by very important factors that should be recognized. In a significant percentage of patients, an atypical pathogen can be identified together with an additional cause. The significance of multiple causes has not been clarified sufficiently. The principal diagnostic techniques in use today for the causative diagnosis of CAP are serologic tests. Different serologic methods have been used in various studies and diagnostic criteria are not standardized. In the future it is likely that diagnostic testing will be based on the PCR technique on serum samples. The effectiveness and importance of antimicrobial therapy in some patients with atypical pathogen CAP are unclear. The accepted therapy today for atypical pathogen CAP, which is based on erythromycin, will probably be changed in the near future in favor of the new generations of fluoroquinolone or the new macrolide preparations.

Community-acquired pneumonia

Community-acquired pneumonia (CAP) is a significant cause of morbidity and mortality in all age groups, especially the elderly, which is a patient population that continues to grow. Recently the spectrum and clinical picture of pneumonia has been changing as a reflection of this aging population; this requires a reassessment of and a new approach to the patient with pneumonia. Currently, pneumonia patients are classified as having either community-acquired or hospital-acquired infection rather than typical versus atypical. Patients who have CAP are categorized by age, presence of a coexisting medical illness, and the severity of the pneumonia. The rationale behind categorizing patients is to stratify them in terms of mortality risk to help determine the location of therapy (e.g., outpatient, inpatient, intensive care unit) and focus the choice of initial antimicrobial therapy. Once the decision to hospitalize a patient with pneumonia is made, the next step is to decide on an appropriate diagnostic evaluation and antibiotic therapy. Both decisions have evolved over the last several years since the publication of the American Thoracic Society's CAP guidelines. The current approach to the diagnostic work-up of pneumonia stresses a limited role of diagnostic tests and procedures. The antimicrobial regimen has now evolved into one that is empiric in nature and based on the age of the patient, the presence of coexisting medical disease, and the overall severity of the pneumonia. This process is a dynamic once because bacterial resistance to commonly used antibiotics can further complicate the course of pneumonia therapy, but the impact of resistance on outcome is less clear. Resistance of Streptococcus pneumoniae to penicillin is a prime example of this growing problem, and adjustment to pneumonia therapy may be required. A difficult but not uncommon problem in pneumonia patients is slow recovery and delayed resolution of radiographic infiltrates. Factors that impact negatively on pneumonia resolution include advanced age and the presence of serious comorbid illnesses such as diabetes mellitus, renal disease, or chronic obstructive pulmonary disease. In addition, certain organism factors (e.g., intrinsic virulence) may interact with host factors and advanced age to delay pneumonia resolution. For example, 50% of patients with pneumococcal pneumonia have radiographic clearing at 5 weeks, and the majority clear within 2 to 3 months. Recent data demonstrate that radiographic resolution of CAP is most influenced by the number of lobes involved and the age of the patient. Radiographic clearance of CAP decreases by 20% per decade after age 20, and patients with multilobar infiltrates take longer to clear than those with unilobar disease. In general, when approaching slowly resolving infiltrates after pneumonia, bronchoscopic evaluation and lung biopsy are more likely to yield a specific diagnosis if the patient is a nonsmoker younger than 55 years old with multilobar disease. If the patients has either no identifiable factors associated with prolonged pneumonia resolution or the repeat chest radiograph at 1 month shows no appreciable change, further diagnostic testing is indicated. The route and duration of antibiotic therapy, another detail of the management of CAP patients that has changed recently, is complicated by the fact that the majority of patients with CAP have no pathogen identified. Therefore, in most instances the physician initiates empiric antibiotics on the basis of epidemiologic data. If an etiologic pathogen is identified (either initially or at a later time), then the antibiotic spectrum can be narrowed. When no pathogen is discovered, broad-spectrum empiric antibiotics are continued. (ABSTRACT TRUNCATED)

Community-acquired pneumonia: epidemiology, etiology, treatment

Community-acquired pneumonia is a common and severe illness. S. pneumoniae remains the most common cause of CAP; however, more than 100 microbials cause this illness. Antibiotic treatment is dictated by the severity of the pneumonia.

Community-acquired pneumonia in the elderly. Clinical and nutritional aspects

Community-acquired pneumonia (CAP) in the elderly has a different clinical presentation than CAP in other age groups. Confusion, alteration of functional physical capacity, and decompensation of underlying illnesses may appear as unique manifestations. Malnutrition is also an associated feature of CAP in this population. We undertook a study to assess the clinical and nutritional aspects of CAP requiring hospitalization in elderly patients (over 65 yr of age). One hundred and one patients with pneumonia, consecutively admitted to a 1,000-bed teaching hospital over an 8-mo period, were studied (age: 78 +/- 8 yr, mean +/- SD). Nutritional aspects and the mental status of patients with pneumonia were compared with those of a control population (n = 101) matched for gender, age, and date of hospitalization. The main symptoms were dyspnea (n = 71), cough (n = 67), and fever (n = 64). The association of these symptoms with CAP was observed in only 32 patients. The most common associated conditions were cardiac disease (n = 38) and chronic obstructive pulmonary disease (COPD) (n = 30). Seventy-seven (76%) episodes of pneumonia were clinically classified as typical and 24 as atypical. There was no association between the type of isolated microorganism and the clinical presentation of CAP, except for pleuritic chest pain, which was more common in pneumonia episodes caused by classical microorganisms (p = 0.02). This was confirmed by a multivariate analysis (relative risk [RR] = 11; 95% confidence interval [CI]: 1.7 to 65; p = 0.0099). The prevalence of chronic dementia was similar in the pneumonia cohort (n = 25) and control group (n = 18) (p = 0.22). However, delirium or acute confusion were significantly more frequent in the pneumonia cohort than in controls (45 versus 29 episodes; p = 0.019). Only 16 patients with pneumonia were considered to be well nourished, as compared with 47 control patients (p = 0.001). Kwashiorkor-like malnutrition was the predominant type of malnutrition (n = 65; 70%) in the pneumonia patients as compared with the control patients (n = 31; 31%) (p = 0.001). The observed mortality was 26% (n = 26). Pleuritic chest pain is the only clinical symptom that can guide an empiric therapeutic strategy in CAP (typical versus atypical pneumonia). Both delirium and malnutrition were very common clinical manifestations of CAP in our study population.