The effects of incorporating a pneumonia severity index into the admission protocol for community-acquired pneumonia

Advancements in the Management of Severe Community-Acquired Pneumonia: A Comprehensive Narrative Review

Pneumonia, classified as a lower respiratory tract illness, affects different parts of the bronchial system as well as alveoli and can present with varying severities depending on co-morbidities and causative pathogens. It can be broadly classified using the setting in which it was acquired, namely the community or hospital setting, the former being more common and spreading through person-to-person droplet transmission. Community-acquired pneumonia (CAP) is currently the fourth leading cause of death worldwide, and its high mortality makes continual insight into the management of the condition worthwhile. This review explores the literature specifically for severe CAP (sCAP) and delves into the diagnosis, various modalities of treatment, and management of the condition. This condition can be defined as pneumonia requiring mechanical ventilation in the ICU and/or presenting with sepsis and organ failure due to pneumonia. The disease process is characterized by inflammation of the lung parenchyma, initiated by a combination of pathogens and lowered local defenses. Acute diagnosis of the condition is vital in reducing negative patient outcomes, namely through clinical presentation, blood/sputum cultures, imaging modalities such as computed tomography scan, and inflammatory markers, identifying common causative pathogens such as Streptococcus pneumoniae, rhinovirus, Legionella, and viral influenza. Pathogens such as Escherichia coli should also be investigated in patients with chronic obstructive pulmonary disease. The mainstay of treating sCAP includes rapid ICU admission once a diagnosis has been confirmed, initiating sepsis protocol, and treatment with combined empiric antibiotic regimens consisting of beta-lactams and macrolides. Corticosteroid use alongside antibiotics shows promise in reducing inflammation, but its use has to be judged on a case-by-case basis. New drugs such as omadacycline, delafloxacin, and zabofloxacin have shown valid evidence for the treatment of resistant causative organisms. The main guidelines for preventing sCAP include maintaining a healthy lifestyle, and annual pneumococcal and influenza vaccines are recommended for the most vulnerable patient groups, such as those with COPD and immunosuppression.

Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America

Background: This document provides evidence-based clinical practice guidelines on the management of adult patients with community-acquired pneumonia.

Methods: A multidisciplinary panel conducted pragmatic systematic reviews of the relevant research and applied Grading of Recommendations, Assessment, Development, and Evaluation methodology for clinical recommendations.

Results: The panel addressed 16 specific areas for recommendations spanning questions of diagnostic testing, determination of site of care, selection of initial empiric antibiotic therapy, and subsequent management decisions. Although some recommendations remain unchanged from the 2007 guideline, the availability of results from new therapeutic trials and epidemiological investigations led to revised recommendations for empiric treatment strategies and additional management decisions.

Conclusions: The panel formulated and provided the rationale for recommendations on selected diagnostic and treatment strategies for adult patients with community-acquired pneumonia.

Severity scoring systems for pneumonia: current understanding and next steps

PURPOSE OF REVIEW

To describe the current understanding and clinical applicability of severity scoring systems in pneumonia management.

RECENT FINDINGS

Severity scores in community-acquired pneumonia are strong markers of mortality, but are not necessarily clinical decision-aid tools. The use of severity scores to support outpatient care in low-risk patients has moderate-to-strong evidence available in the literature, mainly for the pneumonia severity index, and must be applied together with clinical judgment. It is not clear that severity scores are helpful to guide empiric antibiotic treatment. The inclusion of biomarkers and performance status might improve the predictive performance of the well known severity scores in community-acquired pneumonia. We should improve our methods for score evaluation and move toward the development of decision-aid tools.

SUMMARY

The application of the available evidence favors the use of severity scoring systems to improve the delivery of care for pneumonia patients. The incorporation of new methodologies and the formulation of different questions other than mortality prediction might help the further development of severity scoring systems, and enhance their support to the clinical decision-making process for the pneumonia-management cascade.

Factors Associated With Pneumonia Severity in Children: A Systematic Review

Community-acquired pneumonia in children is associated with significant morbidity and mortality; however, data are limited in predicting which children will have negative outcomes, including clinical deterioration, severe disease, or development of complications. The Pediatric Infectious Diseases Society/Infectious Diseases Society of America (PIDS/IDSA) pediatric pneumonia guideline includes criteria that were modified from adult criteria and define pneumonia severity to assist with resource allocation and site-of-care decision-making. However, the PIDS/IDSA criteria have not been formally developed or validated in children. Definitions for mild, moderate, and severe pneumonia also vary across the literature, further complicating the development of standardized severity criteria. This systematic review summarizes (1) the current state of the evidence for defining and predicting pneumonia severity in children as well as (2) emerging evidence focused on risk stratification of children with pneumonia.

Hospitalization for community-acquired febrile urinary tract infection: validation and impact assessment of a clinical prediction rule

Background

There is a lack of severity assessment tools to identify adults presenting with febrile urinary tract infection (FUTI) at risk for complicated outcome and guide admission policy. We aimed to validate the Prediction Rule for Admission policy in Complicated urinary Tract InfeCtion LEiden (PRACTICE), a modified form of the pneumonia severity index, and to subsequentially assess its use in clinical practice.

Methods

A prospective observational multicenter study for model validation (2004–2009), followed by a multicenter controlled clinical trial with stepped wedge cluster-randomization for impact assessment (2010–2014), with a follow up of 3 months. Paricipants were 1157 consecutive patients with a presumptive diagnosis of acute febrile UTI (787 in validation cohort and 370 in the randomized trial), enrolled at emergency departments of 7 hospitals and 35 primary care centers in the Netherlands.

The clinical prediction rule contained 12 predictors of complicated course. In the randomized trial the PRACTICE included guidance on hospitalization for high risk (>100 points) and home discharge for low risk patients (<75 points), in the control period the standard policy regarding hospital admission was applied. Main outcomes were effectiveness of the clinical prediction rule, as measured by primary hospital admission rate, and its safety, as measured by the rate of low-risk patients who needed to be hospitalized for FUTI after initial home-based treatment, and 30-day mortality.

Results

A total of 370 patients were included in the randomized trial, 237 in the control period and 133 in the intervention period. Use of PRACTICE significantly reduced the primary hospitalization rate (from 219/237, 92%, in the control group to 96/133, 72%, in the intervention group, p < 0.01). The secondary hospital admission rate after initial outpatient treatment was 6% in control patients and 27% in intervention patients (1/17 and 10/37; p < 0.001).

Conclusions

Although the proposed PRACTICE prediction rule is associated with a lower number of hospital admissions of patients presenting to the ED with presumptive febrile urinary tract infection, futher improvement is necessary to reduce the occurrence of secondary hospital admissions.

Trial registration

NTR4480 http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4480, registered retrospectively 25 mrt 2014 (during enrollment of subjects).

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2509-3) contains supplementary material, which is available to authorized users.

Predicting Severe Pneumonia Outcomes in Children

BACKGROUND

Substantial morbidity and excessive care variation are seen with pediatric pneumonia. Accurate risk-stratification tools to guide clinical decision-making are needed.

METHODS

We developed risk models to predict severe pneumonia outcomes in children (<18 years) by using data from the Etiology of Pneumonia in the Community Study, a prospective study of community-acquired pneumonia hospitalizations conducted in 3 US cities from January 2010 to June 2012. In-hospital outcomes were organized into an ordinal severity scale encompassing severe (mechanical ventilation, shock, or death), moderate (intensive care admission only), and mild (non-intensive care hospitalization) outcomes. Twenty predictors, including patient, laboratory, and radiographic characteristics at presentation, were evaluated in 3 models: a full model included all 20 predictors, a reduced model included 10 predictors based on expert consensus, and an electronic health record (EHR) model included 9 predictors typically available as structured data within comprehensive EHRs. Ordinal regression was used for model development. Predictive accuracy was estimated by using discrimination (concordance index).

RESULTS

Among the 2319 included children, 21% had a moderate or severe outcome (14% moderate, 7% severe). Each of the models accurately identified risk for moderate or severe pneumonia (concordance index across models 0.78-0.81). Age, vital signs, chest indrawing, and radiologic infiltrate pattern were the strongest predictors of severity. The reduced and EHR models retained most of the strongest predictors and performed as well as the full model.

CONCLUSIONS

We created 3 risk models that accurately estimate risk for severe pneumonia in children. Their use holds the potential to improve care and outcomes.

Validation of modified early warning score using serum lactate level in community-acquired pneumonia patients. The National Early Warning Score-Lactate score

STUDY OBJECTIVE

The aim of this study was to investigate the prognostic prediction power of a newly introduced early warning score modified by serum lactate level, the National Early Warning Score-Lactate (NEWS-L) score, among community-acquired pneumonia (CAP) patients. We also compared the NEWS-L score with the pneumonia severity index (PSI) and CURB-65.

METHODS

We designed a retrospective observational study and collected data on confirmed adult CAP patients who visited the study hospital between October 2013 and September 2014. Variables relevant to, the NEWS-L score, PSI, and CURB-65 were extracted from electronic medical records. Survival status at hospital discharge was determined in the same manner. The NEWS-L score was calculated as NEWS-L=NEWS+serum lactate level (mmol/L). The NEWS-L was divided into quartiles. The ability to predict mortality was assessed through area under the receiver operating characteristic curve analysis and calibration analysis.

RESULTS

A total of 553 patients were enrolled, and the inpatient mortality rate was 10.8% (n=60). Mortality rates increased incrementally in conjunction with the NEWS-L quartiles: first quartile, 2.2%; second quartile, 7.9%; third quartile, 9.6%; and fourth quartile, 23.9%. The area under the receiver operating characteristic curve of the NEWS-L score was 0.73 (95% confidence interval [CI], 0.66-0.80), which showed no significant difference from that of the PSI (0.68; 95% CI, 0.61-0.76; P=.28) and CURB-65 (0.66; 95% CI, 0.59-0.73; P=.06).

CONCLUSIONS

The newly introduced early warning score modified by serum lactate level, NEWS-L score, was comparable to PSI and CURB-65, for predicting inpatient mortality among adult CAP patients.

Severe thinness is associated with mortality in patients with community-acquired pneumonia: a prospective observational study

PURPOSE

This study aimed to investigate the probability of 30-day mortality based on body mass index (BMI) assessment combined with pneumonia severity index (PSI) in patients with community-acquired pneumonia (CAP) and to determine whether being underweight is an independent risk factor contributing to 30-day mortality.

BASIC PROCEDURES

A prospectively collected database was analyzed retrospectively. Multivariable logistic regression analysis was performed to determine whether BMI is an independent predictor of mortality in patients with CAP by adjusting for PSI and other factors found significant in univariable analysis. Mortality predictability of BMI and PSI was evaluated using area under the receiver operating characteristic curve analyses.

MAIN FINDINGS

A total of 1403 patients were assessed in this study. In multivariable regression analysis, severe thinness (BMI<16 kg/m2), hypoalbuminemia (albumin<3.3 mg/dL), and PSI IV and V were predictive factors for 30-day mortality in patients with CAP. In terms of mortality prediction, the accuracy of PSI was 0.67 (95% confidence interval [CI], 0.63-0.71) as measured by the area under the receiver operating characteristic curve. When hypoalbuminemia was combined with PSI, the predictive accuracy significantly increased to 0.71 (95% CI, 0.66-0.75; P=.02). The addition of severe thinness to PSI and hypoalbuminemia further increased the accuracy significantly to 0.74 (95% CI, 0.70-0.78) (P=.005).

PRINCIPAL CONCLUSIONS

Severe thinness (BMI<16 kg/m2) was associated with 30-day mortality in patients with CAP, showing improved prognostic performance when combined with PSI. We propose that physicians consider a patient's nutritional state using BMI when predicting mortality in CAP.

Bacteremia prediction model using a common clinical test in patients with community-acquired pneumonia

PURPOSE

The aim of this study was to construct a bacteremia prediction model using commonly available clinical variables in hospitalized patients with community-acquired pneumonia (CAP).

BASIC PROCEDURES

A prospective database including patients who were diagnosed with CAP in the emergency department was analyzed. Independent risk factors were investigated by using multivariable analysis in 60% of the cohort. We assigned a weighted value to predictive factor and made a prediction rule. This model was validated both internally and externally with the remaining 40% of the cohort and a cohort from an independent hospital. The low-risk group for bacteremia was defined as patients who have a risk of bacteremia less than 3%.

MAIN FINDINGS

A total of 2422 patients were included in this study. The overall rate of bacteremia was 5.7% in the cohort. The significant factors for predicting bacteremia were the following 7 variables: systolic blood pressure less than 90 mm Hg, heart rate greater than 125 beats per minute, body temperature less than 35 °C or greater than 40 °C, white blood cell less than 4000 or 12,000 cells per microliter, platelets less than 130,000 cells per microliter, albumin less than 3.3 g/dL, and C-reactive protein greater than 17 mg/dL. After using our prediction rule for the validation cohorts, 78.7% and 74.8% of the internal and external validation cohorts were classified as low-risk bacteremia groups. The areas under the receiver operating characteristic curves were 0.75 and 0.79 for the internal and external validation cohorts.

PRINCIPAL CONCLUSIONS

This model could provide guidelines for whether to perform blood cultures for hospitalized CAP patients with the goal of reducing the number of blood cultures.

Hospital admission decision for patients with community-acquired pneumonia

Where to treat patients is probably the single most important decision in the management of community-acquired pneumonia (CAP), with a substantial impact on both patients' outcomes and health-care costs. Several factors can contribute to the decision of the site of care for CAP patients, including physicians' experience and clinical judgment and severity scores developed to predict mortality, as well as social and health-care-related issues. The recognition, both in the community and in the emergency department, of the presence of severe sepsis and acute respiratory failure and the coexistence with unstable comorbidities other than CAP are indications for hospital admission. In all the other cases, physician's choice to admit CAP patients should be validated against at least one objective tool of risk assessment, with a clear understanding of each score's limitations.