Admission Chest Radiograph Lacks Sensitivity in the Diagnosis of Community-Acquired Pneumonia

doi:10.1097/MAJ.0b013e31818ad805

The American Journal of the Medical Sciences

Volume 337, Issue 4, April 2009, Pages 236-240

https://doi.org/10.1097/MAJ.0b013e31818ad805 Get rights and content

Abstract

Introduction

The clinical and epidemiological significance of community-acquired pneumonia (CAP) with a chest radiograph demonstrating no parenchymal infiltrate has not been studied. We determined the percentage of patients with a clinical diagnosis of CAP who did not have radiographic opacifications and compared this group with patients with CAP and radiographic infiltrates.

Methods

Patients admitted with a diagnosis of CAP were identified. Clinical history, physical examination, laboratory studies, and microbiological cultures were reviewed in a random sample of 105 patients. Admission and subsequent chest radiographs were interpreted without knowledge of the clinical data.

Results

Twenty-one percent (22/105) of patients with a clinical diagnosis of CAP had negative chest radiographs at presentation. Demographic, clinical, and laboratory data were the same in both groups. Fifty-five percent of patients with initially negative chest radiographs who had follow-up studies developed an infiltrate within 48 hours.

Conclusions

In patients admitted with a clinical diagnosis of CAP, the initial chest radiograph lacks sensitivity and may not demonstrate parenchymal opacifications in 21% of patients. Moreover, greater than half of patients admitted with a negative chest radiograph will develop radiographic infiltrates within 48 hours. Further studies are needed to develop evidence-based criteria for the diagnosis of CAP.

Section snippets

Patient Selection

Patients with CAP admitted to the University Hospital at the University of Cincinnati Medical Center (an urban 450 bed academic medical center) were identified retrospectively by the ICD-9 codes (480.0–487.0) available through hospital information systems. Charts were reviewed to ensure that the final clinical diagnosis of CAP was made by the physician at discharge. The only inclusion criterion was the final clinical diagnosis as determined by the attending physician. Of 520 patients admitted

RESULTS

Twenty-one percent (22/105) of patients with a diagnosis of CAP had negative initial chest radiographs. Patients with negative chest radiographs were not different in age or gender when compared with those with positive radiographs (Table 1). Disease severity, as calculated by the PSI, was 75.1 on average for those with positive chest radiographs and 81.9 for those with negative initial studies (P = 0.28). The PSI was not able to be calculated due to HIV infection for 12 patients with positive

DISCUSSION

In this study, 21% of patients admitted with a clinical diagnosis of CAP had a negative initial chest radiograph. Similarly, Basi et al¹⁶ found 1/3 of patients admitted to Canadian hospitals and managed using a CAP pathway did not have chest radiograph findings indicative of pneumonia. Unlike most previous investigations of CAP, our study and the investigation by Basi et al¹⁶ used the actual clinical diagnosis as inclusion criteria. Additionally, when 2 expert thoracic radiologists reviewed 282

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Adults with symptoms of pneumonia: a prospective comparison of patients with and without infiltrates on chest radiography
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Citation Excerpt :
Sensitivity analysis excluding patients who underwent chest CT imaging did however not show a major change to the ORs (Supplementary Table 3). It is known that a portion of patients with a negative CXR on admission will develop an infiltrate within 48 hours [10]. The majority in both groups had only one CXR.
Most studies on patients hospitalized with community-acquired pneumonia (CAP) require confirmation of an infiltrate by chest radiography, but in practice admissions are common among patients with symptoms of pneumonia without an infiltrate (SPWI). The aim of this research was to compare clinical characteristics, microbial etiology, and outcomes among patients with CAP and SPWI.
Adults suspected of CAP were prospectively recruited at Landspitali University Hospital over a 1-year period, 2018 to 2019. The study was population based. Those admitted with two or more of the following symptoms were invited to participate: temperature ≥38°C or ≤36°C, sweating, shaking/chills, chest pain, a new cough, or new onset of dyspnea. Primary outcome was mortality at 30 days and one year.
Six hundred twenty-five cases were included, 409 with CAP and 216 with SPWI; median age was 75 (interquartile range [IQR] 64–84) and 315 (50.4%) were females. Patients with CAP were more likely to have fever (≥38.0°C) (66.9% [273/408]) vs. 49.3% (106/215), p < 0.001), a higher CRP (median 103 [IQR 34–205] vs. 55 (IQR 17–103), p < 0.001), identification of Streptococcus pneumoniae (18.0% [64/355]) vs. 6.3% (10/159) of tested, p = 0.002) and to receive antibacterial treatment (99.5% [407/409]) vs. 87.5% (189/216), p < 0.001) but less likely to have a respiratory virus detected (25.4% [33/130]) vs. 51.2% (43/84) of tested, p < 0.001). The adjusted odds ratios for 30-day and 1 year mortality of SPWI compared to CAP were 0.86 (95% CI 0.40–1.86) and 1.46 (95% CI 0.92–2.32), respectively.
SPWI is a common cause of hospitalization and despite having fever less frequently, lower inflammatory markers, and lower detection rate of pneumococci than patients with CAP, mortality is not significantly different.
Infection source hidden behind compression fracture
2022, Visual Journal of Emergency Medicine
Citation Excerpt :
For example, patients with early pneumonia may not present significant findings on chest radiographs.2 However, in some of these patients, follow-up chest radiography helps diagnose pneumonia.3 Therefore, imaging tests should, if possible, be evaluated repeatedly when undetected infection sources are suspected by history takings and physical examinations.
Diagnostic accuracy of point-of-care tests in acute community-acquired lower respiratory tract infections. A systematic review and meta-analysis
2022, Clinical Microbiology and Infection
Citation Excerpt :
Interestingly the learning curve seems relatively fast [33,34] with accuracy not changing significantly if the lung ultrasound is performed by highly skilled sonographers compared with non-experienced personnel. This result raises questions as to why chest X-ray remains the reference standard for CA-LRTI diagnosis [35–37]. More methodologically rigorous studies conducted at different community settings and in LMICs may contribute to better define lung ultrasound's potential at POC.
Point-of-care tests could be essential in differentiating bacterial and viral acute community-acquired lower respiratory tract infections and driving antibiotic stewardship in the community.
To assess diagnostic test accuracy of point-of-care tests in community settings for acute community-acquired lower respiratory tract infections.
Multiple databases (MEDLINE, EMBASE, Web of Science, Cochrane Library, Open Gray) from inception to 31 May 2021, without language restrictions.
Diagnostic test accuracy studies involving patients at primary care, outpatient clinic, emergency department and long-term care facilities with a clinical suspicion of acute community-acquired lower respiratory tract infections. The comparator was any test used as a comparison to the index test. In order not to limit the study inclusion, the comparator was not defined a priori.
Four investigators independently extracted data, rated risk of bias, and assessed the quality using QUADAS-2.
The measures of diagnostic test accuracy were calculated with 95% CI.
A total of 421 studies addressed at least one point-of-care test. The diagnostic performance of molecular tests was higher compared with that of rapid diagnostic tests for all the pathogens studied. The accuracy of stand-alone signs and symptoms or biomarkers was poor. Lung ultrasound showed high sensitivity and specificity (90% for both) for the diagnosis of bacterial pneumonia. Rapid antigen-based diagnostic tests for influenza, respiratory syncytial virus, human metapneumovirus, and Streptococcus pneumoniae had sub-optimal sensitivity (range 49%–84%) but high specificity (>80%).
Physical examination and host biomarkers are not sufficiently reliable as stand-alone tests to differentiate between bacterial and viral pneumonia. Lung ultrasound shows higher accuracy than chest X-ray for bacterial pneumonia at emergency department. Rapid antigen-based diagnostic tests cannot be considered fully reliable because of high false-negative rates. Overall, molecular tests for all the pathogens considered were found to be the most accurate.
Time to antibiotic administration and patient outcomes in community-acquired pneumonia: results from a prospective cohort study
2021, Clinical Microbiology and Infection
Citation Excerpt :
Finally, the very restrictive disease definition must also be mentioned as a limitation. Some CAP patients develop infiltrates at a later stage or have very discrete radiological changes [28]. These patients were not captured by our study.
Community-acquired pneumonia (CAP) is a frequently occurring disease linked to high mortality and morbidity. Previous studies indicated that the administration of antibiotics within 4 hrs of admission can improve key patient outcomes associated with CAP, such as mortality and time to clinical stability. However, the results have been heterogeneous and may not be applicable to all healthcare settings. Therefore, we designed a cohort study to estimate the impact of timely antibiotic administration on outcomes in patients admitted with CAP.
The impact of antibiotic administration within 4 hrs of admission and other covariates were estimated for 30-day mortality, stability within 72 hrs, 30-day readmission and time to discharge, using multivariable regression models. Sensitivity analyses were performed on a subset of patients with the most severe CAP and a propensity score matched cohort.
In total, 2264 patients were included. Of these, 273 (12.1%) died within 30 days of admission, 1277 (56.4%) were alive and stable within 72 hrs and 334 (14.8%) were discharged alive and readmitted within 30 days. Median length of hospital stay was 5 days (interquartile range 3–8). In all models, the administration of antibiotics within 4 hrs of admission had no significant effect on the outcomes. The adjusted odds ratios (OR) derived from the multivariable models for 30-day mortality, stability within 72 hrs and 30-day readmission were 1.01 (95% confidence interval (CI) 0.76; 1.33), 0.88 (95% CI 0.74; 1.05) and 1.05 (95% CI 0.82; 1.34). The adjusted hazard ratio (HR) for time to discharge was 1.00 (95% CI 0.91; 1.10).
A strict 4-hr threshold for antibiotic administration in all patients admitted with CAP is not reasonable. Instead, our results suggested that patients should be triaged and prioritized according to age, comorbidities, clinical condition and pneumonia severity.
Point-Of-Care Ultrasound for Lung Assessment in Patients With Severe Scoliosis and Chest Deformities: An Emergency Department Case Series
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Diagnosing pneumonia and other lung conditions can be challenging in patients with severe intellectual or physical disabilities or severe chest deformities. Physical examination is sometimes difficult to perform and the frequently requested chest x-ray (CXR) study is often of little value in the diagnostic approach to this population. Point-of-care lung ultrasound (US) is an emerging diagnostic tool with particularly high level of accuracy in detecting pneumonia, pleural effusion, and pneumothorax.
This case series describes four cases demonstrating the usefulness of point-of-care US in a pediatric emergency department for lung assessment in patients for differentiation and diagnosis of acute causes of acute respiratory symptoms, in whom clinical features or CXR failed to confirm or exclude pulmonary complications.
In patients with chest deformities, pulmonary complications can be disproportionately frequent. Lung US should be recognized as an important adjunctive tool in this subset of patients to detect pneumonia, pleural effusions, and pneumothorax. When used proactively, it can reduce unnecessary radiation exposure, provide more certainty in determining the diagnosis, and, most importantly, inform correct and timely management.
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Clinical InvestigationAdmission Chest Radiograph Lacks Sensitivity in the Diagnosis of Community-Acquired Pneumonia

Abstract

Introduction

Methods

Results

Conclusions

Section snippets

Patient Selection

RESULTS

DISCUSSION

Lancet

Am J Med

Am J Med

Infect Dis Clin North Am

Chest

Chest

Does this patient have community-acquired pneumonia? Diagnosing pneumonia by history and physical exam

JAMA

Management of community-acquired pneumonia

N Engl J Med

American Thoracic Society Guidelines for the Management of Adults with Community-Acquired Pneumonia

Am J Respir Crit Care Med

Update of Practice Guidelines for the Management of Community-Acquired Pneumonia in Immunocompetent Adults

Clin Infect Dis

BTS Guidelines for the Management of Community Acquired Pneumonia in Adults

Thorax

Canadian guidelines for the initial management of community-acquired pneumonia: an evidence-based update by the Canadian Infectious Diseases Society and the Canadian Thoracic Society. The Canadian Community-Acquired Pneumonia Working Group

Clin Infect Dis

Early switch from intravenous to oral antibiotics in hospitalized patients with bacteremic community-acquired Streptococcus pneumoniae pneumonia

Arch Intern Med

Clinical Investigation
Admission Chest Radiograph Lacks Sensitivity in the Diagnosis of Community-Acquired Pneumonia