Signs and Symptoms That Rule out Community-Acquired Pneumonia in Outpatient Adults: A Systematic Review and Meta-Analysis

Handheld Ultrasound Devices Used by Newly Certified Operators for Pneumonia in the Emergency Department-A Diagnostic Accuracy Study

The diagnostic accuracy of handheld ultrasound (HHUS) devices operated by newly certified operators for pneumonia is unknown. This multicenter diagnostic accuracy study included patients prospectively suspected of pneumonia from February 2021 to February 2022 in four emergency departments. The index test was a 14-zone focused lung ultrasound (FLUS) examination, with consolidation with air bronchograms as diagnostic criteria for pneumonia. FLUS examinations were performed by newly certified operators using HHUS. The reference standard was computed tomography (CT) and expert diagnosis using all medical records. The sensitivity and specificity of FLUS and chest X-ray (CXR) were compared using McNemar's test. Of the 324 scanned patients, 212 (65%) had pneumonia, according to the expert diagnosis. FLUS had a sensitivity of 31% (95% CI 26-36) and a specificity of 82% (95% CI 78-86) compared with the experts' diagnosis. Compared with CT, FLUS had a sensitivity of 32% (95% CI 27-37) and specificity of 81% (95% CI 77-85). CXR had a sensitivity of 66% (95% CI 61-72) and a specificity of 76% (95% CI 71-81) compared with the experts' diagnosis. Compared with CT, CXR had a sensitivity of 69% (95% CI 63-74) and a specificity of 68% (95% CI 62-72). Compared with the experts' diagnosis and CT diagnosis, FLUS performed by newly certified operators using HHUS devices had a significantly lower sensitivity for pneumonia when compared to CXR (p < 0.001). FLUS had a significantly higher specificity than CXR using CT diagnosis as a reference standard (p = 0.02). HHUS exhibited low sensitivity for pneumonia when used by newly certified operators.

Pulse Oximetry as an Aid to Rule Out Pneumonia among Patients with a Lower Respiratory Tract Infection in Primary Care

Guidelines recommend chest X-rays (CXRs) to diagnose pneumonia and guide antibiotic treatment. This study aimed to identify clinical predictors of pneumonia that are visible on a chest X-ray (CXR+) which could support ruling out pneumonia and avoiding unnecessary CXRs, including oxygen saturation. A secondary analysis was performed in a clinical trial that included patients with suspected pneumonia in Swiss primary care. CXRs were reviewed by two radiologists. We evaluated the association between clinical signs (heart rate > 100/min, respiratory rate ≥ 24/min, temperature ≥ 37.8 °C, abnormal auscultation, and oxygen saturation < 95%) and CXR+ using multivariate analysis. We also calculated the diagnostic performance of the associated clinical signs combined in a clinical decision rule (CDR), as well as a CDR derived from a large meta-analysis (at least one of the following: heart rate > 100/min, respiratory rate ≥ 24/min, temperature ≥ 37.8 °C, or abnormal auscultation). Out of 469 patients from the initial trial, 107 had a CXR and were included in this study. Of these, 26 (24%) had a CXR+. We found that temperature and oxygen saturation were associated with CXR+. A CDR based on the presence of either temperature ≥ 37.8 °C and/or an oxygen saturation level < 95% had a sensitivity of 69% and a negative likelihood ratio (LR-) of 0.45. The CDR from the meta-analysis had a sensitivity of 92% and an LR- of 0.37. The addition of saturation < 95% to this CDR increased the sensitivity (96%) and decreased the LR- (0.21). In conclusion, this study suggests that pulse oximetry could be added to a simple CDR to decrease the probability of pneumonia to an acceptable level and avoid unnecessary CXRs.

Overruling of Procalcitonin-Guided Antibiotics for Lower Respiratory Tract Infections in Primary Care: Ancillary Study of a Randomized Controlled Trial

BACKGROUND

Lower respiratory tract infections (LRTIs) in primary care are a promising target for antibiotic stewardship. A clinical trial in Switzerland showed a large decrease in antibiotic prescriptions with procalcitonin guidance (cut-off < 0.25 µg/L) compared with usual care. However, one-third of patients with low procalcitonin at baseline received antibiotics by day 28.

AIM

To explore the factors associated with the overruling of initial procalcitonin guidance.

DESIGN AND SETTING

Secondary analysis of a cluster randomized trial in which patients with an LRTI were included.

METHOD

Using the characteristics of patients, their disease, and general practitioners (GPs), we conducted a multivariate logistic regression, adjusted for clustering.

RESULTS

Ninety-five out of 301 (32%) patients with low procalcitonin received antibiotics by day 28. Factors associated with an overruling of procalcitonin guidance were: a history of chest pain (adjusted OR [aOR] 1.81, 95% confidence interval 1.03-3.17); a prescription of chest X-ray by the GP (aOR 4.65, 2.32-9.34); a C-reactive protein measured retrospectively above 100 mg/L (aOR 7.48, 2.34-23.93, reference ≤ 20 mg/L); the location of the GP practice in an urban setting (aOR 2.27, 1.18-4.37); and the GP's number of years of experience (aOR per year 1.05, 1.01-1.09).

CONCLUSIONS

Overruling of procalcitonin guidance was associated with GPs' socio-demographic characteristics, pointing to the general behavioral problem of overprescription by physicians. Continuous medical education and communication training might support the successful implementation of procalcitonin point-of-care tests aimed at antibiotic stewardship.

Pneumonia Update for Emergency Clinicians

Purpose of Review

Many new concepts in diagnosis, management, and risk stratification of patients with pneumonia have been described recently. The COVID pandemic made importance of viruses as dangerous pathogens of pneumonia quite clear while several non-invasive measures for patients with respiratory failure gained a more wide-spread usage.

Recent Findings

Studies continue to examine feasibility of bedside ultrasound as a tool in accurate diagnosis of pneumonia in the emergency department, and several new antibiotics have been approved for treatment while others are in late-stage clinical trials. Additionally, the Infectious Diseases Society, American Thoracic Society, and their European counterparts published updated guidelines in recent years. For differences important to emergency medicine clinicians and new emphasis as compared to the prior guidelines, please see Table 1. Several new antibiotics have been approved recently but remain relatively unknown to emergency clinicians as their use is frequently restricted to infectious disease specialists.Table 1

[Acute Cough in Adult Patients]

Background

Acute cough (< 8 weeks) is a frequent complaint in family practice consultations. The most common cause are respiratory infections. The Guideline "Acute and chronic cough" of the German College of General Practitioners and Family Physicians (DEGAM) was updated in 2021 and contains recommendations for an evidence-based approach for the management of acute cough in primary care.

Methods

The guideline has been updated in accordance with the findings of a systematic search of the literature for international guidelines and systematic reviews. All recommendations were developed by an interdisciplinary guideline committee and agreed by formal consensus.

Results

History-taking, exclusion of red flags and a physical examination are the basis of diagnostic evaluation. If an acute, uncomplicated bronchitis is likely, no laboratory tests, sputum diagnostics, or chest x-rays should be performed, and antibiotics should not be administered. Evidence based strategies to avoid antibiotic therapy (delayed prescribing, shared decision making, point-of-care-tests) can be used. There is inadequate evidence for the efficacy of antitussive or expectorant drugs against acute cough. The state of the evidence for phytotherapeutic agents is heterogeneous; clinical importance is minimal. COVID-19 should currently be considered in cases of acute respiratory symptoms. If specific symptoms or red flags occur, further diagnoses in the context of acute cough such as community-acquired pneumonia, influenza disease and exacerbations of chronic respiratory diseases (bronchial asthma, COPD) should be taken into consideration.

Conclusions

These evidence-based recommendations are intended to reduce the use of antibiotics to treat colds and acute bronchitis, for which they are not indicated. Further clinical trials of symptomatic treatments for cough should be performed in order to extend the evidence base.

Diagnosing community-acquired pneumonia via a smartphone-based algorithm: a prospective cohort study in primary and acute-care consultations

BACKGROUND

Community-acquired pneumonia (CAP) is an essential consideration in patients presenting to primary care with respiratory symptoms; however, accurate diagnosis is difficult when clinical and radiological examinations are not possible, such as during telehealth consultations.

AIM

To develop and test a smartphone-based algorithm for diagnosing CAP without need for clinical examination or radiological inputs.

DESIGN AND SETTING

A prospective cohort study using data from participants aged >12 years presenting with acute respiratory symptoms to a hospital in Western Australia.

METHOD

Five cough audio-segments were recorded and four patient-reported symptoms (fever, acute cough, productive cough, and age) were analysed by the smartphone-based algorithm to generate an immediate diagnostic output for CAP. Independent cohorts were recruited to train and test the accuracy of the algorithm. Diagnostic agreement was calculated against the confirmed discharge diagnosis of CAP by specialist physicians. Specialist radiologists reported medical imaging.

RESULTS

The smartphone-based algorithm had high percentage agreement (PA) with the clinical diagnosis of CAP in the total cohort (n = 322, positive PA [PPA] = 86.2%, negative PA [NPA] = 86.5%, area under the receiver operating characteristic curve [AUC] = 0.95); in participants 22-<65 years (n = 192, PPA = 85.7%, NPA = 87.0%, AUC = 0.94), and in participants aged ≥65 years (n = 86, PPA = 85.7%, NPA = 87.5%, AUC = 0.94). Agreement was preserved across CAP severity: 85.1% (n = 80/94) of participants with CRB-65 scores 1 or 2, and 87.7% (n = 57/65) with a score of 0, were correctly diagnosed by the algorithm.

CONCLUSION

The algorithm provides rapid and accurate diagnosis of CAP. It offers improved accuracy over current protocols when clinical evaluation is difficult. It provides increased capabilities for primary and acute care, including telehealth services, required during the COVID-19 pandemic.

Accuracy of Signs and Symptoms for the Diagnosis of Community-acquired Pneumonia: A Meta-analysis

BACKGROUND

Community-acquired pneumonia (CAP) is an important source of morbidity and mortality. However, overtreatment of acute cough illness with antibiotics is an important problem, so improved diagnosis of CAP could help reduce inappropriate antibiotic use.

METHODS

This was a meta-analysis of prospective cohort studies of patients with clinically suspected pneumonia or acute cough that used imaging as the reference standard. All studies were reviewed in parallel by two researchers and quality was assessed using the QUADAS-2 criteria. Summary measures of accuracy included sensitivity, specificity, likelihood ratios, the diagnostic odds ratio, and the area under the receiver operating characteristic curve (AUROCC) and were calculated using bivariate meta-analysis.

RESULTS

We identified 17 studies, of which 12 were judged to be at low risk of bias and the remainder at moderate risk of bias. The prevalence of CAP was 10% in nine primary care studies and was 20% in seven emergency department studies. The probability of CAP is increased most by an abnormal overall clinical impression suggesting CAP (positive likelihood ratio [LR+] = 6.32, 95% CI = 3.58 to 10.5), egophony (LR+ = 6.17, 95% CI = 1.34 to 18.0), dullness to percussion (LR+ = 2.62, 95% CI = 1.14 to 5.30), and measured temperature (LR+ = 2.52, 95% CI = 2.02 to 3.20), while it is decreased most by the absence of abnormal vital signs (LR- = 0.25, 95% CI = 0.11 to 0.48). The overall clinical impression also had the highest AUROCC at 0.741.

CONCLUSIONS

While most individual signs and symptoms were unhelpful, selected signs and symptoms are of value for diagnosing CAP. Teaching and performing these high value elements of the physical examination should be prioritized, with the goal of better targeting chest radiographs and ultimately antibiotics.

Treatment update: Outpatient management of community-acquired pneumonia

Pneumonia is a leading cause of morbidity and mortality in the US and a primary cause of hospitalization nationwide. A recent guideline update from the American Thoracic Society and Infectious Diseases Society of America provides evidence-based recommendations for managing adults with community-acquired pneumonia in the outpatient setting.

Clinical management decisions for adults with prolonged acute cough: Frequency and associated factors

BACKGROUND

Uncomplicated episodes of prolonged acute cough are usually viral and self-limited, but despite evidence and recommendations to the contrary, they are often treated with antibiotics.

METHODS

Mixed cross-sectional and prospective observational study of adults 18 years or older presenting to two urgent care centers with a cough of 7 to 56 days as their chief complaint. Factors associated with cough duration and clinical decisions were analyzed by univariate and multivariate logistic regression.

RESULTS

Of the 125 enrolled patients, 118 (94%) received an antibiotic, 97 (78%) a cough suppressant, 87 (70%) a systemic corticosteroid, and 39 (31%) a chest X-ray (CXR). Longer duration of cough was associated with the presence of self-reported wheezing or noises (adjusted odds ratio 6.29, 95% CI 1.36-29.16) while the presence of both wheezing and crackles on a clinician chest exam was associated with shorter duration (aOR 0.03, 95% CI 0.00-0.27). A clinician was more likely to order a CXR in patients with dyspnea (aOR 3.01, 95% CI 1.21-7.49), less likely to prescribe a systemic corticosteroid in patients with crackles (aOR 0.27, 95% CI 0.09-0.82), and more likely to prescribe a cough suppressant to older patients (1.04 per additional year of age, 95% CI 1.01-1.07).

CONCLUSIONS

Systemic corticosteroids and cough suppressants are being prescribed at high rates in patients with uncomplicated acute cough in the urgent care setting. Additional studies to determine if similar rates are seen in other urgent care centers, or in other contemporary ambulatory settings are warranted.