Simplified prediction rule for prognosis of patients with severe community-acquired pneumonia in ICUs

A Broad Learning System to Predict the 28-Day Mortality of Patients Hospitalized with Community-Acquired Pneumonia: A Case-Control Study

This study was to conduct a model based on the broad learning system (BLS) for predicting the 28-day mortality of patients hospitalized with community-acquired pneumonia (CAP). A total of 1,210 eligible CAP cases from Chifeng Municipal Hospital were finally included in this retrospective case-control study. Random forest (RF) and an eXtreme Gradient Boosting (XGB) models were used to develop the prediction models. The data features extracted from BLS are utilized in RF and XGB models to predict the 28-day mortality of CAP patients, which established two integrated models BLS-RF and BLS-XGB. Our results showed the integrated model BLS-XGB as an efficient broad learning system (BLS) for predicting the death risk of patients, which not only performed better than the two basic models but also performed better than the integrated model BLS-RF and two well-known deep learning systems-deep neural network (DNN) and convolutional neural network (CNN). In conclusion, BLS-XGB may be recommended as an efficient model for predicting the 28-day mortality of CAP patients after hospital admission.

Significance of the Modified NUTRIC Score for Predicting Clinical Outcomes in Patients with Severe Community-Acquired Pneumonia

Nutritional status could affect clinical outcomes in critical patients. We aimed to determine the prognostic accuracy of the modified Nutrition Risk in Critically Ill (mNUTRIC) score for hospital mortality and treatment outcomes in patients with severe community-acquired pneumonia (SCAP) compared to other clinical prediction rules. We enrolled SCAP patients in a multi-center setting retrospectively. The mNUTRIC score and clinical prediction rules for pneumonia, as well as clinical factors, were calculated and recorded. Clinical outcomes, including mortality status and treatment outcome, were assessed after the patient was discharged. We used the receiver operating characteristic (ROC) curve method and multivariate logistic regression analysis to determine the prognostic accuracy of the mNUTRIC score for predicting clinical outcomes compared to clinical prediction rules, while 815 SCAP patients were enrolled. ROC curve analysis showed that the mNUTRIC score was the most effective at predicting each clinical outcome and had the highest area under the ROC curve value. The cut-off value for predicting clinical outcomes was 5.5. By multivariate logistic regression analysis, the mNUTRIC score was also an independent predictor of both clinical outcomes in SCAP patients. We concluded that the mNUTRIC score is a better prognostic factor for predicting clinical outcomes in SCAP patients compared to other clinical prediction rules.

Prognostic value of initial chest CT findings for clinical outcomes in patients with COVID-19

Rationale: To identify whether the initial chest computed tomography (CT) findings of patients with coronavirus disease 2019 (COVID-19) are helpful for predicting the clinical outcome. Methods: A total of 224 patients with laboratory-confirmed COVID-19 who underwent chest CT examination within the first day of admission were enrolled. CT findings, including the pattern and distribution of opacities, the number of lung lobes involved and the chest CT scores of lung involvement, were assessed. Independent predictors of adverse clinical outcomes were determined by multivariate regression analysis. Adverse outcome were defined as the need for mechanical ventilation or death. Results: Of 224 patients, 74 (33%) had adverse outcomes and 150 (67%) had good outcomes. There were higher frequencies of more than four lung zones involved (73% vs 32%), both central and peripheral distribution (57% vs 42%), consolidation (27% vs 17%), and air bronchogram (24% vs 13%) and higher initial chest CT scores (8.6±3.4 vs 5.4±2.1) (P < 0.05 for all) in the patients with poor outcomes. Multivariate analysis demonstrated that more than four lung zones (odds ratio [OR] 3.93; 95% confidence interval [CI]: 1.44 to 12.89), age above 65 (OR 3.65; 95% CI: 1.11 to 10.59), the presence of comorbidity (OR 5.21; 95% CI: 1.64 to 19.22) and dyspnea on admission (OR 3.19; 95% CI: 1.35 to 8.46) were independent predictors of poor outcome. Conclusions: Involvement of more than four lung zones and a higher CT score on the initial chest CT were significantly associated with adverse clinical outcome. Initial chest CT findings may be helpful for predicting clinical outcome in patients with COVID-19.

Clinical and Chest Radiography Features Determine Patient Outcomes in Young and Middle-aged Adults with COVID-19

Background Chest radiography has not been validated for its prognostic utility in evaluating patients with coronavirus disease 2019 (COVID-19). Purpose To analyze the prognostic value of a chest radiograph severity scoring system for younger (nonelderly) patients with COVID-19 at initial presentation to the emergency department (ED); outcomes of interest included hospitalization, intubation, prolonged stay, sepsis, and death. Materials and Methods In this retrospective study, patients between the ages of 21 and 50 years who presented to the ED of an urban multicenter health system from March 10 to March 26, 2020, with COVID-19 confirmation on real-time reverse transcriptase polymerase chain reaction were identified. Each patient's ED chest radiograph was divided into six zones and examined for opacities by two cardiothoracic radiologists, and scores were collated into a total concordant lung zone severity score. Clinical and laboratory variables were collected. Multivariable logistic regression was used to evaluate the relationship between clinical parameters, chest radiograph scores, and patient outcomes. Results The study included 338 patients: 210 men (62%), with median age of 39 years (interquartile range, 31-45 years). After adjustment for demographics and comorbidities, independent predictors of hospital admission (n = 145, 43%) were chest radiograph severity score of 2 or more (odds ratio, 6.2; 95% confidence interval [CI]: 3.5, 11; P < .001) and obesity (odds ratio, 2.4 [95% CI: 1.1, 5.4] or morbid obesity). Among patients who were admitted, a chest radiograph score of 3 or more was an independent predictor of intubation (n = 28) (odds ratio, 4.7; 95% CI: 1.8, 13; P = .002) as was hospital site. No significant difference was found in primary outcomes across race and ethnicity or those with a history of tobacco use, asthma, or diabetes mellitus type II. Conclusion For patients aged 21-50 years with coronavirus disease 2019 presenting to the emergency department, a chest radiograph severity score was predictive of risk for hospital admission and intubation. © RSNA, 2020 Online supplemental material is available for this article.

Intensive care and invasive ventilation in the elderly patient, implications of chronic lung disease and comorbidities

Aims: Elderly patients have an increasing prevalence of illness that requires consideration of critical care and invasive ventilatory support. Although critical care of even the very elderly can provide value, with increasing age the potential risks of treatment and diminishing returns with respect to quality and quantity of life result in a need for careful evaluation. Variable combinations of impaired organ function, active disease and residual pathology from past disease and injury all affect critical care, with the consequence that the elderly are a very heterogeneous population. Recognizing that critical care is a limited resource, it is important to identify patients who may be at increased risk or least likely to benefit from treatment. Patients with functional impairments, nutritional deficiencies and multiple comorbidities may be at highest risk of poor outcomes. Those with very severe disease, extreme age and requirements for prolonged ventilatory support have high in-hospital mortality. Functional impairments, comorbidities and severity of illness are usually more important considerations than chronologic age. The objective of this review is to identify how common problems of the elderly affect critical care and decisions concerning use of invasive ventilatory support.

Applicability of Prediction Rules in Patients With Community-Acquired Pneumonia Requiring Intensive Care: A Pilot Study

Little attention has been paid to developing prediction rules that could assist in deciding which patients with community-acquired pneumonia (CAP) need intensive care. Four existing prediction rules were examined to determine if any could predict the need for intensive care in these patients. The prediction rules studied were British Thoracic Society (BTS), Conte et al, Leroy et al, and Fine et al. Thirty-two patients admitted to the medical or coronary intensive care unit (ICU) during 1 year with pneumonia Diagnosis Related Group 079 or 089 were evaluated. The sensitivity of each rule for identifying a need for ICU admission in our group was BTS .72 using both rules together, Conte et al .47, Leroy et al .56, and Fine et al .84. It was concluded that these rules poorly identify the need for ICU admission for patients with severe CAP. Of the 4 rules tested, the BTS rule was the simplest, and the Fine et al rule was the most sensitive. None of them performed well enough to be used for decision making in individual patients.

[Severe community-acquired pneumonia admitted at the intensive care unit: main clinical and bacteriological features and prognostic factors: a Tunisian experience]

INTRODUCTION

Severe community-acquired pneumonia (SCAP) remains a major cause of death. The aim of this study was to describe the main clinical and bacteriological features and to determine predictive factors for death in patients with SCAP who were admitted in intensive care unit (ICU) in a Tunisian setting.

METHOD

It is a retrospective study conducted between March 2005 and December 2010 at the intensive care unit of the University Hospital of Mahdia (Tunisia). All patients hospitalized at the ICU with a SCAP diagnosis according to the American Thoracic Society criteria were included.

RESULTS

Two hundred and nine patients (mean age: 64±16 years, and mean SAPS II: 42±17) were included. Overall, 24% had a bacteriological diagnosis. Streptococcus pneumoniae was the most frequently detected. Use of mechanical ventilation was required in 57% of patients and 45% experimented septic shock upon admission. The mortality rate at ICU was 29% (n=60). In multivariate analysis, a septic shock at admission and the use of mechanical ventilation were both associated with death.

CONCLUSION

SCAP were associated with high mortality in the ICU.

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.

Hospital and long-term outcomes of ICU-treated severe community- and hospital-acquired, and ventilator-associated pneumonia patients

BACKGROUND

Our purpose was to analyse the association of pneumonia types with hospital and long-term outcomes of intensive care unit (ICU)-treated pneumonia patients.

METHODS

The occurrence of pneumonia was retrospectively evaluated among prospectively registered patients admitted into a mixed university-level ICU during a 14-month period. Their age, severity of underlying disease, malignancy, immunosuppressive therapy and organ dysfunctions were recorded, as well as the length of hospital stay and short- and long-term mortalities.

RESULTS

There were 117 severe community-acquired pneumonia (SCAP), 66 hospital-acquired pneumonia (HAP) and 25 ventilator-associated pneumonia (VAP) cases among the 817 patients admitted. ICU and hospital mortality did not differ between pneumonia groups. VAP and HAP patients had more malignant underlying diseases than SCAP patients (P < 0.001). HAP patients were older than SCAP and VAP patients (P = 0.023). The admission Acute Physiology and Chronic Health Evaluation II scores did not differ between the groups (P > 0.90). The patients with VAP had higher Sequential Organ Failure Assessment maximum scores compared with patients with SCAP and HAP (P < 0.001). In an adjusted multivariate logistic regression model, there were no significant differences in odds ratios for hospital mortality between the three pneumonia types. Mortality among the hospital survivors during the 12-month follow-up period was 18% (16/89) in the SCAP group, 35% (18/51) in the HAP group and 41% (7/17) in the VAP group (P = 0.023).

CONCLUSION

The type of pneumonia (i.e. SCAP, HAP or VAP) had no significant association with hospital mortality, whereas the SCAP patients had the lowest 1-year mortality.

CURB-65, PSI, and APACHE II to Assess Mortality Risk in Patients With Severe Sepsis and Community Acquired Pneumonia in PROWESS

Background: Patients with community-acquired pneumonia (CAP) comprised 35.6% of the overall phase 3 Recombinant Human Activated Protein C Worldwide Evaluation in Severe Sepsis (PROWESS) study and 33.1% of the placebo arm. We investigated the use of CURB-65, the Pneumonia Severity Index (PSI), and Acute Physiology and Chronic Health Evaluation II (APACHE II) prediction scores to identify the CAP population from the PROWESS placebo arm at the greatest mortality risk. Methods: Patients were classified as having CAP if the lung was the primary infection site and the patient originated from home. The abilities of CURB-65, PSI, and APACHE II scores to determine the 28-day and in-hospital mortality were compared using receiver operator characteristic (ROC) curves and the associated areas under the curve. Results: PROWESS enrolled 278 patients with CAP in the placebo arm. The areas under the ROC curves for PSI = 5, CURB-65 ≥3, and APACHE II ≥25 for predicting 28-day (c = 0.65, 0.66, and 0.64, respectively) and in-hospital mortality (c = 0.65, 0.65, and 0.64, respectively) were not statistically different from each other. The 28-day mortality of patients with a PSI score of 5, CURB-65 ≥3, and APACHE II ≥25 was 41.6%, 37.9%, and 43.5%, respectively. Conclusions: Despite early diagnosis and appropriate antibiotic therapy, conventionally treated CAP with PSI = 5, CURB-65 ≥3, or APACHE II ≥25 has an unacceptably high mortality. In this study, PSI, CURB-65, and APACHE II scoring systems perform similarly in predicting the 28-day and in-hospital mortality; however, differences in the categorization of severe CAP were observed and there was a significant mortality in patients with a CURB-65 <3 and PSI <5.

[Community-acquired pneumonia: a 7-years descriptive study. Usefulness of the IDSA/ATS 2007 in the assessment of ICU admission]

OBJECTIVE

To describe the clinical characteristics and outcomes of patients with community-acquired pneumonia (CAP) admitted to the Intensive Care Unit (ICU). To evaluate new ATS/IDSA criteria to identify patients with CAP who required admission to ICU.

DESIGN

Retrospective analysis of prospective collected data in a 7-year period (2000-2007).

SETTING

Medical-surgical ICU with 16 beds.

PATIENTS

All patients with severe CAP admitted to the ICU (n=147). PRIMARY ENDPOINTS: Clinical and microbiological characteristics. Prognostic factors. Comparison of patients admitted in the ICU and ATS/IDSA criteria (group 1: > or = 1 major criterion, group 2: > or = 3 minor criteria and group 3: no criterion).

INTERVENTION

None.

RESULTS

Admission to the ICU is required for patients with acute respiratory failure (60.5%) and with septic shock (28.5%). A total of 71.4%, had an identifiable microbial etiology, S. pneumoniae being the most frequently isolated. Mean time to antibiotic therapy was 4.3+/-4.2h, this being adequate in 97.1%. ICU global mortality rate was 32%. Prognostic factors associated with higher mortality were acute renal failure (OR:4.7), mechanical ventilation (OR:3.4), non-identifiable etiology (OR:4.2) and non-S. pneumonia etiology (OR:3.5). Sixty-eight percent of the patients were included in the first group of the ATS/IDSA criteria and 21% in the second group.

CONCLUSIONS

CAP mortality is still high despite early antibiotic therapy, especially in those patients with a non-S. pneumonia etiology or who require mechanical ventilation. Almost 90% of the ICU admissions were identified by the new criteria from ATS/IDSA.

Validation of a prediction rule for prognosis of severe community-acquired pneumonia

In a previous study, we developed a prognostic prediction rule, based on nine prognostic variables, capable to estimate and to adjust the mortality rate of patients admitted in intensive care unit for severe community-acquired pneumonia. A prospective multicenter study was undertaken to evaluate the performance of this rule. Five hundred eleven patients, over a 7-year period, were studied. The ICU mortality rate was 29.0%. In the 3 initial risk classes, we observed significantly increasing mortality rates (8.2% in class I, 22.8% in class II and 65.0% in class III) (p<0.001). Within each initial risk class, the adjustment risk score identified subclasses exhibiting significantly different mortality rates: 3.9% and 33.3% in class I; 3.1%, 12.9% and 63.3% in class II; and 55.8% and 82.5% in class III. Compared with mortality rates predicted by our previous study, only a few significant differences were observed. Our results demonstrate the performance and reproductibility of this prognostic prediction rule.

Impact of thrombocytopenia on outcome of patients admitted to ICU for severe community-acquired pneumonia

OBJECTIVE

To evaluate the prevalence and the prognostic value of thrombocytopenia in patients admitted to ICU for severe community-acquired pneumonia.

METHODS

Multicentre observational study was conducted in 7 ICUs in the north of France over a 19-year period (1987-2005). The primary outcome measure was the ICU mortality.

RESULTS

Eight hundred and twenty-two patients were studied. A platelet count < 150x10(9)/L was observed at ICU admission in 202 (25%) patients. Admission platelet count was between 101 and 149x10(9)/L, 51 and 100x10(9)/L, 21 and 50x10(9)/L, and < or = 20x10(9)/L in 100, 61, 32 and 9 patients, respectively. ICU mortality rate was 35.4%. Classifying patients into 3 categories with the following cut-offs of platelet count, > or = 150x10(9)/L, 51-149x10(9)/L, and < or = 50x10(9)/L, we observed a significant increase in ICU mortality rates which were 30.8% in the first group, 44.1% in the second group and 70.7% in the last one (p<0.0001). In multivariate analysis, thrombocytopenia < or = 50x10(9)/L appeared as an independent predictor of mortality (AOR=4.386).

CONCLUSIONS

In patients admitted to ICU for severe community-acquired pneumonia, thrombocytopenia has a high prevalence and influences the outcome.

Prognostic scoring systems: which one is best?

PURPOSE OF REVIEW

In the initial evaluation of patients with community-acquired pneumonia, a number of important assessments are made, including that of the severity of the illness. This assessment will determine the appropriate site of care, diagnostic work-up, and choice of empiric antibiotics. A number of severity assessment tools have been developed and some of the recent findings are reviewed.

RECENT FINDINGS

A number of studies of the efficacy of the individual scoring systems, as well as comparator studies, have been undertaken. A significant number of patients with community-acquired pneumonia in Pneumonia Severity Index classes I and II are admitted to hospital and several of these patients suffer complications. Clinical and social factors other than those contained in the scoring systems need to be taken into consideration when deciding about hospitalization of patients with community-acquired pneumonia. A number of studies of the efficacy of the various scoring systems in predicting 'severe pneumonia' have been undertaken, as well as studies of their accuracy in the sub-set of patients with pneumococcal infections and in the elderly.

SUMMARY

The various scoring systems have reasonable sensitivity and specificity and their own strengths and weaknesses, but should always be used in association with good clinical judgment.

Community-acquired pneumonia requiring admission to an intensive care unit: a descriptive study

Severe community-acquired pneumonia (CAP) requiring admission to an intensive care unit (ICU) has been inadequately studied. We compared characteristics and outcomes of patients with CAP who were admitted to the ICU with those of patients managed on the ward. Of the 3675 patients hospitalized with CAP, 374 (10%) were admitted to the ICU. The main reason for ICU admission was respiratory failure requiring intubation and ventilation (n = 303, 81%), although this indication decreased with increasing age (p < 0.05 for trend). Most patients (62%) required mechanical ventilation for 3 days or less. The following factors were predictive of ICU admission on multivariable analysis: younger age, smoker, limitation of functional status, absence of cough or pleurisy, presence of chronic obstructive pulmonary disease, substance abuse, elevated serum creatinine, abnormal serum glucose concentration, and a respiratory rate of <16 or >24 breaths per minute. Patients with low Pneumonia Severity Index scores and low CURB-65 scores were admitted to the ICU based on clinical judgment that appeared to supersede objective scoring. Severe CAP requiring admission to the ICU is common, and the decision about which patients to admit often requires clinical judgment that in many cases appears at odds with various validated pneumonia severity scoring systems.

Early evolution of arterial oxygenation in severe community-acquired pneumonia: a prospective observational study

PURPOSE

Acute respiratory failure requiring mechanical ventilation in severe community-acquired pneumonia has been shown to be a significant negative prognostic factor. We analyzed the early evolution of the Pao(2)/Fio(2) ratio and evaluated its clinical value as an outcome predictor.

MATERIALS AND METHODS

This is a prospective study conducted in a tertiary referral hospital. In 62 adult patients requiring early mechanical ventilation due to severe community-acquired pneumonia, we measured serial changes in Pao(2)/Fio(2) ratio and other clinical variables within the first 48 hours of mechanical ventilation and compared the difference between survivors and nonsurvivors.

RESULTS

The initial Pao(2)/Fio(2) ratio was lower in nonsurvivors (n = 27) than in survivors (n = 35) (158.0 +/- 55.8 vs 117.9 +/- 50.6, P = .025). Over the next 48 hours, the ratio increased significantly in survivors but not in nonsurvivors (analysis of variance, P < .001). An increase in Pao(2)/Fio(2) ratio greater than 56 mm Hg had a sensitivity of 75% and a specificity of 81% of survival. A definite causative pathogen was identified in 36 patients (58%) and the 3 most commonly isolated pathogens were Streptococcus pneumoniae, Staphylococcus aureus, and Klebsiella pneumoniae. Ten patients received inadequate initial empirical antimicrobial therapy, in which the Pao(2)/Fio(2) ratio change was significantly less than those who were adequately treated (analysis of variance, P < .001). Mortality was much higher (86% [6/7]) in patients who received inadequate antibiotics and where Pao(2)/Fio(2) ratio change was less than 56 mm Hg. On multivariate analysis, trend changes in Pao(2)/Fio(2) ratio over 48 hours, shock, and Acute Physiology and Chronic Health Evaluation II score were documented to be independent predictors of mortality.

CONCLUSIONS

A progressive improvement of Pao(2)/Fio(2) ratio during the first 48 hours of mechanical ventilation indicates favorable outcome. Serial measurement of this ratio should be considered in decision making for therapeutic strategy.

[Evaluation of clinical practice in patients admitted with community-acquired pneumonia over a 4-year period]

OBJECTIVE

Since March 2000 we have been using a clinical practice guideline in the management of patients diagnosed with community-acquired pneumonia (CAP). The objective of this study was to analyze the evolution of quality of care received by these patients.

PATIENTS AND METHODS

This was a prospective observational study comparing the process of care and outcomes of 4 consecutive 1-year periods (March 1, 2000 through February 29, 2004) in patients admitted for CAP.

RESULTS

Over the 4 years studied, the following statistically significant trends were observed: reductions in hospital admissions (P< .001), length of hospital stay (P< .05), and total duration of antibiotic treatment (P< .05); and increases in the coverage of atypical pathogens (P< .001) and administration of antibiotics within 8 hours of hospital arrival (P< .001). No significant differences were found in readmissions within 30 days, or in-hospital and 30-day mortality. Two other areas for improvement were also identified: a low percentage of admissions to the intensive care unit (4.4%) and the rate of unnecessary hospitalization of low-risk patients (36.8%).

CONCLUSIONS

Systematic monitoring of the indicators of our clinical guidelines provided us with information about our clinical practice and facilitated an evaluation of the same. Many of these indicators were found to have evolved favorably and areas of improvement were identified.

Swedish guidelines for the management of community-acquired pneumonia in immunocompetent adults

This document presents the evidence-based guidelines of the Swedish Society of Infectious Diseases for the management of adult immunocompetent patients with community-acquired pneumonia (CAP), who are assessed at hospital. The prognostic score 'CURB-65' is recommended for all CAP patients in the emergency room. The score provides an assessment tool for the decision regarding outpatient treatment or level of hospital supervision, the choice of microbiological investigations, and empirical antibiotic treatment. In patients with non-severe CAP (CURB-65 score 0-2) we recommend initial narrow-spectrum antibiotic treatment, orally or intravenously, primarily directed at Streptococcus pneumoniae. In those with CURB-65 score 3, penicillin G or a cephalosporin intravenously is recommended. For CURB-65 score 0-3 atypical pathogens should be covered only when they are suspected on clinical or epidemiological grounds. In patients with CURB-65 score 4-5 intravenous combination therapy with either cephalosporin/macrolide or penicillin G/fluoroquinolone is recommended. Efforts should be made to identify the CAP aetiology in order to support the ongoing antibiotic treatment or to suggest treatment alterations. Recommended measures for prevention of CAP include influenza -- and pneumococcal -- vaccination to risk groups and efforts for smoking cessation.

Neumonías comunitarias graves del adulto

Las neumonías agudas comunitarias son causa frecuente de hospitalización y mortalidad. El reconocimiento inmediato de las formas graves según criterios simples, clínicos, radiológicos y de laboratorio, es una etapa esencial para un tratamiento rápido en el servicio de reanimación con el fin de controlar los fallos orgánicos. La obtención de muestras apropiadas para realizar estudios microbiológicos precede al tratamiento antibiótico, que se debe instaurar con rapidez después de diagnosticar la neumonía. Pese a las técnicas de identificación, sólo la mitad de las neumonías se documentan adecuadamente. El tratamiento antibiótico, en principio empírico, integra los gérmenes patógenos, tanto extracelulares como intracelulares, que producen neumonías con mayor frecuencia; siempre debe ser activo contra el neumococo, la bacteria implicada más a menudo. La asociación de un betalactámico y un macrólido o una fluoroquinolona es la que mejor responde a este objetivo. En las recomendaciones más comunes, las fluoroquinolonas activas contra los neumococos sustituyen a los fármacos precedentes. En el caso excepcional de los pacientes con factores de riesgo especiales, el tratamiento empírico debe tener en cuenta Pseudomonas aeruginosa. La gravedad de parte de las neumonías comunitarias justifica el que se recurra a tratamientos complementarios. Se debe evaluar de nuevo el tratamiento antibiótico en las 72 horas siguientes a su instauración, a fin de valorar su eficacia, adaptar el tratamiento en caso necesario y simplificarlo. El mantenimiento de antibióticos de amplio espectro expone al paciente a efectos secundarios y contribuye a producir resistencias bacterianas. En cuanto a las neumonías neumocócicas, las fluoroquinolonas activas contra el neumococo podrían representar una alternativa en caso de que el neumococo desarrolle resistencia a los betalactámicos. La mortalidad persistente de las neumonías sigue siendo notable. Esto debe fomentar la mejora del tratamiento inicial y la búsqueda de nuevas opciones terapéuticas.

Prognosis factors and outcome of community-acquired pneumonia needing mechanical ventilation

PURPOSE

To evaluate the variables associated with mortality of patients with community-acquired pneumonia who require mechanical ventilation and to determine the attributable morbidity and intensive care unit (ICU) mortality of community-acquired pneumonia.

MATERIAL AND METHODS

Retrospective cohort study carried out in 361 ICUs from 20 countries including 124 patients who required mechanical ventilation on the first day of admission to the hospital due to acute respiratory failure secondary to severe community-acquired pneumonia. To assess the factors associated with outcome, a forward stepwise logistic regression analysis was performed, and to determine the attributable mortality of community-acquired pneumonia, a matched study design was used.

RESULTS

We found 3 independent variables significantly associated with death in patients with community-acquired pneumonia requiring mechanical ventilation: simplified acute physiological score greater than 45 (odds ratio, 5.5 [95% confidence interval, 1.7-12.3]), shock (odds ratio, 5.7 [95% confidence interval, 1.7-10.1]), and acute renal failure (odds ratio, 3.0 [95% confidence interval, 1.1-4.0]). There was no statistically significant difference in ICU mortality among patients with or without community-acquired pneumonia (32% vs 35%; P=.59).

CONCLUSIONS

Community-acquired pneumonia needing mechanical ventilation is not a disease associated with higher mortality. The main determinants of patient outcome were initial severity of illness and the development of shock and/or acute renal failure.

Pneumonies communautaires graves de l'adulte

Les pneumonies aiguës communautaires sont des causes fréquentes d'hospitalisation et de mortalité. La reconnaissance immédiate des formes sévères sur des critères simples, cliniques, radiologiques et biologiques, est une étape importante pour une prise en charge rapide en réanimation afin de contrôler les défaillances d'organes. Les prélèvements appropriés microbiologiques précèdent l'antibiothérapie qui doit être instituée très rapidement après le diagnostic de pneumonie. Malgré les techniques d'identification, la moitié seulement des pneumonies sont documentées. Cette antibiothérapie, initialement probabiliste, intègre les germes pathogènes les plus souvent responsables, extra- et intracellulaires ; elle doit toujours être active sur le pneumocoque, bactérie la plus fréquente. L'association d'une β-lactamine et d'un macrolide ou d'une fluoroquinolone répond le mieux à cet objectif. Les fluoroquinolones actives sur le pneumocoque se sont substituées aux précédentes dans les plus récentes recommandations. Dans le cas exceptionnel des patients ayant des facteurs de risque particuliers, le traitement probabiliste doit prendre en compte Pseudomonas aeruginosa. La gravité d'une partie des pneumonies communautaires justifie le recours à des traitements adjuvants. L'antibiothérapie doit être réévaluée dans les 72 heures dans le but d'apprécier son efficacité, de l'adapter éventuellement et de la simplifier. La poursuite des antibiotiques à large spectre expose le patient à des effets indésirables et contribue aux résistances bactériennes. Pour les pneumonies dues au pneumocoque, les fluoroquinolones actives sur le pneumocoque pourront constituer une alternative en cas d'évolution importante des résistances du pneumocoque aux β-lactamines. La mortalité persistante des pneumonies reste sévère. Ceci doit stimuler l'amélioration de la prise en charge initiale et faire rechercher de nouvelles thérapeutiques.

Comparison of Levofloxacin and Cefotaxime Combined With Ofloxacin for ICU Patients With Community-Acquired Pneumonia Who Do Not Require Vasopressors

STUDY OBJECTIVES

To evaluate the efficacy and tolerability of levofloxacin (L) as monotherapy in patients with severe community-acquired pneumonia (CAP) in comparison with therapy using a combination of cefotaxime (C) plus ofloxacin (O).

DESIGN

Prospective, randomized 1:1, comparative, open, parallel-group study.

SETTING

Multinational study with 149 sites.

PATIENTS

A total of 398 randomized patients who had been admitted to the ICU with severe CAP without shock, including 308 patients in a modified intent-to-treat population and 271 patients in the per-protocol (PP) population (L group, 139 patients; C + O group, 132 patients).

INTERVENTIONS

Therapy with levofloxacin (500 mg IV, q12h) vs therapy with a C + O combination (C, 1g IV, q8h; O, 200 mg IV, q12h) for 10 to 14 days.

MEASUREMENTS AND RESULTS

The main end point was the clinical efficacy at the end of treatment (ie, the test-of-cure [TOC] visit). The statistical hypothesis was the noninferiority of L therapy to C + O therapy with a 2.5% alpha risk (unilateral) and a 15% maximum set difference. At the TOC visit, a clinical success was observed in 79.1% of patients (L group) and 79.5% of patients (C + O group) in the PP population (difference, -0.4%; 95% confidence interval [CI], -10.79 to 9.97% without adjustment for simplified acute physiology score [SAPS] II at inclusion; difference, -0.3%; 95% CI, -10.13 to 9.58% with adjustment for SAPS II). A satisfactory bacteriologic response was present in 73.7% of L group patients and 77.5% of C + O group patients, including responses of 75.7% and 70.3%, respectively, in the L group and C + O group in the Streptococcus pneumoniae-documented population. In the safety analysis, 20 patients in the L group (10.3%) and 16 patients in the C + O group (8.0%) experienced at least one adverse event that was considered to be treatment-related.

CONCLUSION

L therapy was at least as effective as the combination therapy of C + O in the treatment of a subset of patients with CAP requiring ICU admission. This conclusion cannot be extrapolated to patients requiring mechanical ventilation or vasopressors (ie, those patients in shock).

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.

[Clinical picture and prognostic factors for severe community-acquired pneumonia in adults admitted to the intensive care unit]

OBJECTIVE

In Chile very little information is available on severe community-acquired pneumonia treated in intensive care units. This study describes the clinical picture, prognostic factors, and treatment of adult patients admitted to the intensive care unit for severe community-acquired pneumonia.

PATIENTS AND METHODS

A total of 113 consecutive patients were included in this prospective, descriptive study.

RESULTS

The mean (SD) age of the 113 patients was 73 (15). Of these, 95% had associated comorbidity, and 81% were in the high-risk classes of the Pneumonia Severity Index. Etiology was identified in 31%, and the most common pathogens were Streptococcus pneumoniae (40%), gram negative bacilli (17%), and Mycoplasma pneumoniae (6%). The main complications were the need for mechanical ventilation (45%), septic shock (26%), heart failure (24%), and arrhythmias (15%). Mortality at 30 days was 16.8%, and multivariate analysis revealed the following factors to be associated with a greater risk of death: acute renal failure (odds ratio: 5.1), and glycemia above 300 mg/dL (odds ratio: 7.2).

CONCLUSIONS

The patients with severe pneumonia admitted to the intensive care unit are elderly, with a high level of comorbidity and complications, but most survive.

Chronic pneumonia with Pseudomonas aeruginosa and impaired alveolar fluid clearance

Background

While the functional consequences of acute pulmonary infections are widely documented, few studies focused on chronic pneumonia. We evaluated the consequences of chronic Pseudomonas lung infection on alveolar function.

Methods

P. aeruginosa, included in agar beads, was instilled intratracheally in Sprague Dawley rats. Analysis was performed from day 2 to 21, a control group received only sterile agar beads. Alveolar-capillary barrier permeability, lung liquid clearance (LLC) and distal alveolar fluid clearance (DAFC) were measured using a vascular (¹³¹I-Albumin) and an alveolar tracer (¹²⁵I-Albumin).

Results

The increase in permeability and LLC peaked on the second day, to return to baseline on the fifth. DAFC increased independently of TNF-α or endogenous catecholamine production. Despite the persistence of the pathogen within the alveoli, DAFC returned to baseline on the 5^th day. Stimulation with terbutaline failed to increase DAFC. Eradication of the pathogen with ceftazidime did not restore DAFC response.

Conclusions

From these results, we observe an adequate initial alveolar response to increased permeability with an increase of DAFC. However, DAFC increase does not persist after the 5^th day and remains unresponsive to stimulation. This impairment of DAFC may partly explain the higher susceptibility of chronically infected patients to subsequent lung injury.

[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.

Hydrocortisone Infusion for Severe Community-acquired Pneumonia

We hypothesize that hydrocortisone infusion in severe community-acquired pneumonia attenuates systemic inflammation and leads to earlier resolution of pneumonia and a reduction in sepsis-related complications. In a multicenter trial, patients admitted to the Intensive Care Unit (ICU) with severe community-acquired pneumonia received protocol-guided antibiotic treatment and were randomly assigned to hydrocortisone infusion or placebo. Hydrocortisone was given as an intravenous 200-mg bolus followed by infusion at a rate of 10 mg/hour for 7 days. Primary end-points of the study were improvement in Pa(O(2)):FI(O(2)) (Pa(O(2)):FI(O(2)) > 300 or >/= 100 increase from study entry) and multiple organ dysfunction syndrome (MODS) score by Study Day 8 and reduction in delayed septic shock. Forty-six patients entered the study. At study entry, the hydrocortisone group had lower Pa(O(2)):FI(O(2)), and higher chest radiograph score and C-reactive protein level. By Study Day 8, treated patients had, compared with control subjects, a significant improvement in Pa(O(2)):FI(O(2)) (p = 0.002) and chest radiograph score (p < 0.0001), and a significant reduction in C-reactive protein levels (p = 0.01), MODS score (p = 0.003), and delayed septic shock (p = 0.001). Hydrocortisone treatment was associated with a significant reduction in length of hospital stay (p = 0.03) and mortality (p = 0.009).

Severe Acute Respiratory Syndrome: Correlation between Clinical Outcome and Radiologic Features

PURPOSE

To evaluate whether there is a correlation between the clinical outcomes and radiologic features of severe acute respiratory syndrome (SARS).

MATERIALS AND METHODS

The clinical, laboratory, and radiologic features of 138 patients with SARS were analyzed. Three radiologists in consensus retrospectively assessed the frontal chest radiographs obtained at presentation and during treatment (n = 2045) for the distribution (each lung was divided into upper, middle, and lower zones) and extent of lung parenchymal abnormality. Clinical end points included intensive care unit (ICU) admission and death.

RESULTS

Thirty-six (26.1%) patients required ICU care, and eight (5.8%) died. The patients who required ICU care and/or died had more extensive consolidation on chest radiographs obtained initially (median percentage of consolidation, 3.30%, with interquartile range [IR] of 1.70%-8.78% vs 1.70% [IR, 0%-3.30%]; P < .001) and on day 7 after fever onset (median percentage of consolidation, 15.00% [IR, 6.48%-28.73%] vs 5.00% [IR, 2.50%-7.50%]; P < .001) than did surviving patients who did not require ICU care. Patients with involvement of more than one lung zone on initial and day 7 chest radiographs were more likely to require ICU care and/or die than were those with involvement of one or fewer zones (P < .001). Patients with bilateral pneumonic changes at presentation were more likely to have an adverse outcome than were those with unilateral pneumonia (P < .001). Involvement of more than one lung zone at baseline chest radiography was an independent predictor of ICU admission and/or death (odds ratio, 3.16; 95% confidence interval: 1.07, 9.32; P = .037) after adjustments for other significant factors (ie, patient age, and baseline neutrophil count and lactate dehydrogenase level).

CONCLUSION

More extensive airspace disease at presentation is an independent predictor of adverse outcome in patients with SARS.

Value of initial chest radiographs for predicting clinical outcomes in patients with severe acute respiratory syndrome

PURPOSE

To determine whether the initial chest radiograph is helpful in predicting the clinical outcome of patients with severe acute respiratory syndrome (SARS).

METHODS

Of 343 patients who met the World Health Organization's case definition of probable SARS and who had been admitted to a regional hospital in Hong Kong, 201 patients had laboratory evidence of SARS coronavirus infection. The initial frontal chest radiographs of these 201 patients were assessed in a blinded fashion by 3 radiologists; individual findings were accepted if at least 2 of the radiologists concurred. Independent predictors of an adverse outcome, defined as the need for assisted ventilation, death, or both, were identified by multivariate analysis.

RESULTS

Bilateral disease and involvement of more than two zones on the initial chest radiograph were associated with a higher risk of liver impairment and poor clinical outcome. Forty-two patients (21%) developed an adverse outcome. Multivariate analysis showed that lung involvement of more than two zones (odds ratio [OR] = 7.0; 95% confidence interval [CI]: 2.7 to 17.9), older age (OR for each decade of life = 1.5; 95% CI: 1.1 to 2.0), and shortness of breath on admission (OR = 2.8; 95% CI: 1.1 to 7.4) were independent predictors of an adverse outcome.

CONCLUSION

Frontal chest radiographs on presentation may have prognostic value in patients with SARS.

[Hospital admission, duration of stay and mortality in community-acquired pneumonia in an acute care hospital. Correlation between a pneumonia prognosis index and conventional clinical criteria for assessing severity]

INTRODUCTION

The objective of this study was to evaluate the management of community acquired pneumonia (CAP) according to conventional clinical criteria applied in the emergency room as compared to a pneumonia prognosis index (PPI) (Fine et al. NEJM 1997). We also analyzed which factors were associated with the need for inpatient treatment in PPI risk category III patients.

METHODS

We prospectively enrolled all adults with CAP seen in the emergency room during 1999. The data required to calculate the PPI were collected at admission. Mortality and length of stay were recorded at discharge.

RESULTS

A total of 447 patients with CAP were collected, 55.7% in the high-risk classes IV and V. Twenty-seven patients died (6.1%) and 97% of these were within the high-risk classes. There were 362 hospitalizations; 302 (83%) were classes III, IV and V. The readmission rate increased with increases in the risk class, with a range of 4% for class I to 18% for class IV. Eighty-five patients (19%) were treated on an outpatient basis. Risk class III included 80 patients; 63 (79%) were hospitalized, with a length of stay of 7.89 days. The factor most highly associated with hospitalization in this group was abnormal findings on physical examination or on laboratory testing and radiographic studies. (OR: 7.62 [1.5-35.2]).

CONCLUSION

In our cohort, the PPI was effective for identifying low-risk patients with CAP who could be treated as outpatients. In risk class III patients, the severity of the disease was the strongest predictor of hospitalization, rather than the presence of comorbid conditions.

Hospital-Acquired Pneumonia in Critically Ill Patients

STUDY OBJECTIVES

To identify, in patients experiencing hospital-acquired pneumonia (HAP), prognostic factors present at disease onset and build an algorithm capable of stratifying mortality risk upon HAP onset.

DESIGN

Observational cohort from January 1994 to December 2001.

SETTING

One intensive care unit (ICU) from a university-affiliated, urban teaching hospital.

PATIENTS

All consecutive patients exhibiting bacteriologically documented HAP either on ICU admission or during ICU stay.

INTERVENTIONS

Data collection and multivariate analysis using Chi-Square Automatic Interaction and Detection technique.

RESULTS

168 patients were studied. The overall mean mortality rate was 49.4%. Upon onset of HAP, five independent variables allowed binary stratification of mortality risk. These consisted of underlying diseases (nonfatal versus ultimately and rapidly fatal diseases), Simplified Acute Physiology Score II (less than versus > or =37), platelet count (less than versus > or =150,000/mm3), chest x-ray involvement (1 versus >1 lobe), and PaO2/FiO2 (less than versus > or =167 mm Hg). A branching algorithm consisting of these five variables identified patients with HAP at both low (<35%) and high (>75%) risk of mortality.

CONCLUSION

Mortality in ICU patients with HAP may be predicted early, upon onset of HAP, by the cumulative use of prognostic factors in an algorithm.

Impact of adequacy of initial antimicrobial therapy on the prognosis of patients with ventilator-associated pneumonia

OBJECTIVE

To study the prognostic impact of the appropriateness of initial antimicrobial therapy in patients suffering from ventilator-associated pneumonia (VAP).

DESIGN AND SETTING

Observational cohort from January 1994 to December 2001 in one intensive care unit (ICU) from an university-affiliated, urban teaching hospital.

PATIENTS

All 132 consecutive patients exhibiting bacteriologically documented VAP during ICU stay.

MEASUREMENTS AND RESULTS

Initial antimicrobial treatment was deemed appropriate when the period from initial VAP diagnosis and subsequent administration of antibiotics was within 24 h and all causative pathogens were in vitro susceptible to at least one of the antibiotics of the regimen. Such a treatment was present in 106 episodes. Fifty-eight patients died. In bivariate analysis an appropriate initial antimicrobial therapy was associated with a significantly lower mortality rate (40% vs. 62%). In multivariate analysis the three independent factors present upon VAP onset and associated with death were pulmonary involvement of more than a single lobe on chest radiograph, platelet count less than 150000/mm(3), and Simplified Acute Physiology Score II higher than 37. Appropriate antimicrobial therapy was associated with a nonsignificant trend toward a lower mortality.

CONCLUSIONS

In our cohort the mortality rate was lower in patients suffering from VAP when the initial antimicrobial therapy was appropriate. However, such a factor did not appear as an independent prognostic factor.

Severe community-acquired pneumonia: what's in a name?

PURPOSE OF REVIEW

Formerly, patients with community-acquired pneumonia admitted to an intensive care unit were considered as having the severe form of the disease. Recently, guidelines have distinguished severe and non-severe community-acquired pneumonia based on clinical definitions. In this review, we describe the different definitions of severe community-acquired pneumonia, and whether a differentiation based on these definitions reflects variation in etiology, risk factors, diagnostic approaches and treatment.

RECENT FINDINGS

New definitions do not seem to accurately identify patients with high risks of mortality; patients not admitted to an intensive care unit could also be diagnosed as having severe community-acquired pneumonia. Host-factors, such as genetic factors and underlying diseases, can influence severity of presentation of community-acquired pneumonia. Distribution of pathogens in severe and non-severe disease forms is comparable. Initial antibiotic therapy in patients with severe disease should provide coverage of Streptococcus pneumoniae and Legionella pneumophila, as delay is associated with worse outcomes. However, recent studies also suggested an additional benefit of atypical coverage in non-severe disease. As a result, initial therapy with a beta-lactam plus a macrolide or an anti-pneumococcal fluoroquinolone is recommended for all patients with community-acquired pneumonia. Furthermore, the value of vaccination against pneumococci to prevent episodes of severe disease is yet unknown.

SUMMARY

As current guidelines do not adequately identify patients with high risk of mortality and intensive care unit admittance, clinical judgment remains important. Based on distribution of pathogens, investigational procedures and therapy recommended in recent guidelines, differentiation between severe and non-severe community-acquired pneumonia does not seem useful. Whether atypical coverage indeed has additional value in non-severe or pneumococcal CAP, however, remains to be determined. In addition, the preventive benefit of influenza and pneumococcal vaccination for development of SCAP awaits further evidence.

[Community-acquired pneumonia in the elderly: prognostic factors]

The incidence and mortality rates of community-acquired pneumonia are far higher in the elderly than among younger populations. However, the explanation may lie in the presence of comorbidity rather than in age itself. We performed a retrospective study of 226 patients over the age of 65 years who were admitted to our hospital with a diagnosis of community-acquired pneumonia over a period of 36 months, with the objective of identifying factors predicting mortality and to describe clinical features. The patients' mean age was 78.71 (65-96) years. One hundred forty-two were men (63%) and 84 were women (37%). Upon admission, 27.4% showed signs of altered mental state. The crude mortality rate was 20.8%. Multivariate analysis demonstrated the following independent risk factors associated with higher mortality: serum creatinine > 1.2 mg/dL (RR = 13.93; 95% CI 8.14-16.08); patient previously bedridden (RR = 5.73; 95% CI 3.41-6.79), PaO2/FiO2 < 200 (RR = 5; 95% CI 2.67-6.62) and neoplastic disease (RR = 4.08; 95% CI 1.96-5.24). The presence of chest pain was associated with a lower risk of mortality (RR = 0.11; 95% CI 0.01-0.54). Age itself was not a risk factor. We conclude that pneumonia in the elderly requires hospitalization and that it commonly presents with severe symptoms and high risk of mortality. Risk factors such as those identified in this study may help in the diagnosis and treatment of patients requiring special care.

Defining severe community-acquired pneumonia

Based on the recognition of the main pathophysiologic features of pneumonia and currently available data on prognosis and clinical severity assessment, key points for a definition of severe pneumonia are as follows: 1. Independent predictors of pneumonia severity are factors reflecting acute respiratory failure and severe sepsis or septic shock. 2. In view of the dependence of the development of acute respiratory failure on pulmonary comorbidities, radiographic extension may prove to be an additional independent predictor of severe respiratory compromise. 3. Vital sign abnormalities other than acute respiratory failure and severe hypotension may be independent predictors of severity, particularly in patients presenting in early and asymptomatic stages of severe sepsis. 4. Several pathogens have been shown to have adverse prognostic potential. Because the cause is unknown at the initial evaluation, however, pathogens cannot form part of the criteria for the initial severity assessment. 5. Because pneumonia is a dynamic process, any assessment of severity takes place at an arbitrary point of disease evolution. It would be desirable to define a set of parameters reflecting initial severity as well as a state of increased risk for early deterioration toward severe pneumonia. 6. Severity stratification within the population of patients with severe pneumonia may open the prospect of identifying patients who may have the greatest benefit from intensive care.

Defining prognostic factors in the elderly with community acquired pneumonia: a case controlled study of patients aged > or = 75 yrs

Severity assessment in the elderly with community acquired pneumonia (CAP) may be different compared with younger patients. In particular, age per se may not be of prognostic significance in older patients. A case-control study in 158 patients aged > or = 75 yrs with CAP was conducted to determine the factors associated with in-hospital mortality. Cases were drawn from all patients aged > or = 75 yrs with CAP who died in 1997 in five hospitals in the mid-Trent region of the UK (Nottingham City Hospital, University Hospital Nottingham, Derby Royal Infirmary, Derby City General Hospital and Kings Hill Hospital). Controls were randomly selected from survivors also aged > or = 75 yrs. Factors associated with mortality were identified following a review of the medical casenotes and the contribution of these factors to mortality was determined using multivariate analysis. Absence of fever, tachycardia and chest radiograph features of bilateral involvement or an effusion were independently associated with mortality on multivariate analysis. The British Thoracic Society (BTS) severity rule was 50% sensitive and 64% specific in predicting death while the modified BTS rule displayed 67% sensitivity and 58% specificity. Age was not significantly associated with mortality in this group of patients aged > or = 75 yrs. Similarly, the clinical features employed in the British Thoracic Society rule, namely respiratory rate, diastolic blood pressure and blood urea, were not of prognostic significance and the rule itself performed poorly. The modified British Thoracic Society rule performed better.

Community-acquired pneumonia

Community-acquired pneumonia (CAP) remains a leading cause of morbidity and mortality worldwide and has significant financial implications for health-care systems. The epidemiology and fundamental biology of the disease has evolved, reflecting the human immunodeficiency virus pandemic, increasing world travel, and, as always, poverty. The promise held out by molecular diagnostic technology has yet to deliver in this arena, and antibiotic resistance continues to drive the quest for new antimicrobial agents. The emergence of multidrug-resistant Streptococcus pneumoniae, the microorganism most often implicated as a cause of CAP, continues to threaten treatment options. The evolution of this organism, the persistently high mortality rate associated with CAP, and increasing health-care costs have prompted the publication of guidelines by various authorities that can be used to assist in the initial assessment of the patient and then guide empirical antimicrobial therapy. It is unclear whether these guidelines will have significant impact on cost and mortality, although the trend toward a rational and evidence-based approach to antimicrobial therapy must be a goal to aspire to.