History and physical exam findings help to identify children at low risk for pneumonia
Article Outline
Neuman MI, Monuteaux MC, Scully KJ, Bachur RG. Prediction of pneumonia in a pediatric emergency department. Pediatrics 2011;128:246-53.
Question
Among children who present with suspicion for pneumonia in the emergency department, are there historical and physical examination findings that can be used to develop a clinical decision rule for the use of chest radiography?
Design
Prospective cohort study.
Setting
Urban pediatric emergency department.
Participants
Patients (n=2574) under 21 years of age (median age 2.3 years) who had a chest radiograph performed for suspicion of pneumonia.
Outcomes
Multivariate logistic regression model with pneumonia status as the dependent variable and the historical and physical examination findings as the independent variables. Pneumonia was categorized into 2 groups based on the attending radiologist interpretation of the chest radiograph: radiographic pneumonia (includes definite and equivocal cases of pneumonia) and definite pneumonia.
Main Results
16% of patients had radiographic pneumonia. History of chest pain, focal rales, duration of fever, and oximetry levels at triage were significant predictors of pneumonia. The presence of tachypnea, retractions, and grunting were not associated with pneumonia. Hypoxia (oxygen saturation ≤ 92%) was the strongest predictor of pneumonia (OR: 3.6 [95% CI, 2.0–6.8]). Recursive partitioning analysis revealed that among subjects with O2 saturation >92%, no history of fever, no focal decreased breath sounds, and no focal rales, the rate of radiographic pneumonia was 7.6% (95% CI, 5.3–10.0) and definite pneumonia was 2.9% (95% CI, 1.4–4.4).
Conclusions
Historical and physical examination findings can be used to risk stratify children for risk of radiographic pneumonia.
Commentary
Pneumonia, particularly in younger children and infants, is usually viral, may be occult, and generally carries a favorable prognosis in the absence of complicating medical conditions. Radiographs are ordered in a large percentage of such children, but may neither improve clinical outcomes nor decrease the use of antibiotics or subsequent health services.1 Hence, validated criteria for limiting use of radiographs among healthy non toxic children would be a welcome adjunct to clinical evaluation. Neuman et al in a methodologically strong study, have derived low risk criteria and a potential prediction rule for this purpose in a population of median age 2.5 years. Previous such efforts have involved populations with much higher prevalence of radiographic pneumonia, and, therefore, may have overestimated accuracy when applied to a clinically appropriate context.2 The relatively high proportion (33%) of radiograph positive children admitted to the hospital in the population of Neuman et al may reflect local practice rather than severity. Routine use of a prediction rule to guide practice ideally requires independent prospective validation in multiple populations. Meanwhile, the criteria identified by Neuman et al may usefully inform clinical decision making in similar contexts and settings.
References
- . Randomised controlled trial of clinical outcome after chest radiograph in ambulatory acute lower-respiratory infection in children. Lancet. 1998;351:404–408
- . Tips For Learners Of Evidence-Based Medicine: 5. The Effect Of Spectrum Of Disease On The Performance Of Diagnostic Tests. CMAJ. 2005;173:385–390
PII: S0022-3476(11)01139-5
doi:10.1016/j.jpeds.2011.11.016
© 2012 Mosby, Inc. All rights reserved.
