Chest radiography is often performed on patients hospitalized with typical clinical manifestations of bronchiolitis. We aimed to determine the proportion of subjects with pathologic chest radiographic findings and the clinical predictors associated with pathologic chest radiographic findings in young children admitted with the typical presentation of bronchiolitis.
We obtained the following data at admission: sex, age, neonatal history, past history of hospitalization for respiratory illnesses, heart rate, respiratory rate, the presence of fever, total duration of fever, oxygen saturation, laboratory parameters (i.e., complete blood cell count, high-sensitivity C-reactive protein [hs-CRP], etc.), and chest radiography.
The study comprised 279 young children. Of these, 26 had a chest radiograph revealing opacity (n=24) or atelectasis (n=2). Multivariate logistic regression analysis showed that after adjustment for confounding factors, the clinical predictors associated with pathologic chest radiographic findings in young children admitted with bronchiolitis were elevated hs-CRP level (>0.3 mg/dL) and past history of hospitalization for respiratory illnesses (all
The current study suggests that chest radiographs in young children with typical clinical manifestations of bronchiolitis have limited value. Nonetheless, young children with clinical factors such as high hs-CRP levels at admission or past history of hospitalization for respiratory illnesses may be more likely to have pathologic chest radiographic findings.
Acute respiratory tract infection is one of the most common diseases encountered in the outpatient and/or Emergency Department settings in childhood
In a clinical setting, clinicians often perform chest radiography on children with typical manifestations of bronchiolitis in order to rule out other diseases such as pneumonia or cardio-pulmonary diseases. For example, a survey of clinical practices in the diagnosis and management of 17,397 children with bronchiolitis reported that 72% of them received chest radiographs
In the present study, we aimed to determine the proportion of chest radiographs showing pathologic findings inconsistent with bronchiolitis and the clinical predictors of pathologic chest radiographic findings in young children admitted with a typical presentation of bronchiolitis to an inpatient Pediatric Unit at a general hospital.
This was a retrospective chart review study of all young children hospitalized in the CHA Gangnam Medical Center, CHA University from January 2011 through December 2012 with typical clinical manifestations of bronchiolitis. Young children who met the following criteria were included: (1) children <2 years of age and (2) those presenting with typical clinical manifestations of bronchiolitis: i.e., a constellation of clinical signs and symptoms such as a viral upper respiratory prodrome followed by increased respiratory effort and wheezing
Exclusion criteria were as follows: (1) young children who were infected with
All radiographs were read at admission by physicians and at a later date by a highly experienced radiologist, who is regarded as an expert in pediatric lung diseases (HKC). A second senior staff radiologist (THK) also read the initial 279 radiographs to confirm the “expert” reading. Both study radiologists acknowledged that the children were hospitalized due to respiratory tract illnesses, but were blinded to the details of presentation and the findings of the other participating radiologist.
Nasopharyngeal aspirate specimens were collected at the time of hospitalization by carefully irrigating the young child's nostrils with sterile saline solution. Nasopharyngeal aspirate specimens were analyzed within 24 hours of aspiration for respiratory syncytial viruses (RSV) (A and B), human metapneumovirus, human rhinovirus, influenza A and B viruses, parainfluenza virus (A, B, and C), coronavirus (A and B), and adenovirus. Total viral RNA was obtained from nasopharyngeal aspirate specimens (300 µL) by utilizing Viral Gene-spin Viral DNA/RNA Extraction Kits (iNtRON, Seongnam, Korea) and stocked at −80℃. First-strand cDNA was manufactured by implementing Revert Aid First Strand cDNA Synthesis Kits (Fermentas Inc., Burlington, ON, Canada), followed by polymerase chain reaction (PCR) using Seeplex Respiratory Viruses Detection Kits-1 (Seegene, Seoul, Korea) and the GeneAmp PCR system 9700 (Applied Biosystems, Waltham, MA, USA). All reaction mixtures (20 µL) consisted of 3 µL of cDNA, 4 µL of 5× RV1A or 5× RV1B primer, and 10 µL of 2× Multiplex Master Mix. In short, 2.5 µL of extracted RNA was incorporated with 5× buffer, 0.2mM of each dNTP, 0.5µM of each primer
The chest radiographic findings were divided into benign or pathologic groups
The sample size was assessed for a 95% confidence interval (CI) for the primary outcome. After discussion by the researchers, we assessed the percentage of children with benign chest radiographic findings (i.e., bronchiolitis) and pathologic chest radiographic findings to be ≤3%±2%, with alpha=0.05 and beta=0.2, which produced a total required number of children with bronchiolitis of 260
Data are expressed as median (interquartile range) or number (%) unless otherwise mentioned. Differences between groups were compared by implementing the Mann-Whitney
The study population consisted of 279 children. The median age of the children was 8 months. Approximately 41% of the study subjects were male. The numbers of patients that had chest retraction and wheezing were 41 (14.7%) and 149 (53.4%), respectively. The median hospital stay was 4 days (1–14 days), and the number of children who received antibiotic therapy was 191 (68.5%). Only 26 of 279 children (9.3%) had pathologic chest radiographic findings on chest radiograph; of them, 24 children had opacities and two children had atelectasis.
There were no differences between groups with regard to sex; age; birth weight, height, or head circumference; gestational age; respiratory rate, heart rate, body temperature, or oxygen saturation at admission; the presence of fever prior to admission; duration of fever prior to admission; the presence of chest retraction or wheezes; white blood cell count or total eosinophil count at admission; or virus detected. The total duration of fever (3 [0–5] days vs. 1 [0–3] day,
The diagnostic performance of hs-CRP levels (>0.3 mg/dL) was a sensitivity of 80.8% (95% CI, 60.7–93.5), specificity of 48.5% (95% CI, 42.5–54.6), positive predictive value of 13.0% (95% CI, 8.3–19.2), and negative predictive value of 96.4% (95% CI, 91.7–98.8) for predicting pathologic chest radiographic findings.
We utilized multivariate logistic regression analysis to determine clinical predictors of pathologic chest radiographic findings in children admitted with the typical presentation of bronchiolitis. Multivariate logistic regression analyses results determined that after adjustment for potential confounding factors, including sex and age, pathologic chest radiographic findings were significantly positively associated with hs-CRP (>0.3 mg/dL) and a history of admission due to respiratory illnesses (
In the present study, we aimed to determine the proportion of children with pathologic chest radiographic findings and the clinical predictors in young children hospitalized for bronchiolitis at a general hospital. We were able to demonstrate that the majority of children (90.7%) admitted with the typical presentation of bronchiolitis showed benign chest radiographic findings at admission; however, those with high hs-CRP levels at admission or a history of admission due to respiratory illnesses prior to the current admission were approximately 1.2 times more likely to have pathologic chest radiographic findings.
Subjects with bronchiolitis may also have pneumonia detected by chest X-ray
hs-CRP is a well-established biomarker that is used on a regular basis in clinical settings. It is an acute-phase serum protein in humans, and its level rises rapidly due to the cytokines released in response to infection and inflammation
A history of hospitalization due to respiratory illness is an important aspect of the history in children with respiratory problems in the outpatient department, as the respiratory signs and symptoms in children with previous respiratory problems tend to worsen, ultimately requiring hospitalization
There are some limitations to the present study. First, the current study has inherent limitations due to its retrospective study design. Second, the present study is a single center study conducted at a secondary hospital. Third, lung function measures or objective assessments such as the RDAI clinical score were not available to determine the degree of respiratory difficulty. Fourth, this study lacks a diagnostic “gold standard” to prove the absence of bacterial infection in children with chest abnormalities. It would be ideal to perform chest radiography after a complete review of the expected benefits of chest X-ray in subjects (e.g., subjects with toxic appearance, unconventional presentations, or protracted clinical course). Furthermore, the current research work had only 2 children with atelectasis on their chest x-ray, and recognition of any factors predicting this high-risk finding was beyond calculation.
In conclusion, we found that chest radiographs in young children with a typical presentation of bronchiolitis have limited value; however, those with high hs-CRP levels or a history of admission due to respiratory illnesses prior to admission were approximately 1.2 times more likely to have pathologic chest radiographic findings. Further studies with larger samples sizes are needed to corroborate this finding before a clear conclusion can be drawn.
Variable | Infants with pathologic chest radiographic findings (n=26) | Infants with benign chest radiographic findings (n=253) | |
---|---|---|---|
Male sex | 9 (34.6) | 105 (41.5) | 0.49 |
Age under 3 months | 3 (11.5) | 43 (17.0) | 0.58 |
Birth weight (g) | 3.3 (3.2–3.5) | 3.2 (3.0–3.5) | 0.72 |
Birth height (cm) | 49.5 (48.4–50.0) | 48.8 (47.5–50.0) | 0.67 |
Birth head circumference (cm) | 34.0 (33.9–35.5) | 34.1 (33.4–35.0) | 0.26 |
Gestational age (weeks) | 39.2 (38.4–40.0) | 39.0 (38.2–40.0) | 0.51 |
Respiratory rate at admission (/min) | 36 (32–38) | 36 (34–40) | 0.33 |
Heart rate at admission (/min) | 142 (134–150) | 142 (135–155) | 0.63 |
Body temperature at admission (℃) | 37.7 (37.0–38.4) | 37.4 (37.0–38.3) | 0.44 |
Oxygen saturation at admission (%) | 98 (97–99) | 98 (97–99) | 0.57 |
Presence of fever prior to admission | 18 (69.2) | 139 (54.9) | 0.21 |
Duration of fever prior to admission (day) | 2 (0–4) | 1 (0–3) | 0.33 |
Total duration of fever (day) | 3 (0–5) | 1 (0–3) | 0.007 |
hsCRP (mg/dL) | 1.4 (0.4– 4.1) | 0.4 (0.1–1.3) | 0.02 |
hsCRP (>0.3 mg/dL, n [%]) | 21 (80.8) | 140 (55.3) | 0.01 |
Bronchopulmonary dysplasia | 0 (0) | 0 (0) | |
Past history of admission due to respiratory illness | 8 (30.8) | 28 (11.1) | 0.004 |
Chest retraction | 2 (7.7) | 39 (15.4) | 0.28 |
Wheeze | 12 (46.2) | 137 (54.2) | 0.43 |
White blood cell (/mm3) | 9,860.0 (8,150.0–13,330.0) | 10,410.0 (8,190.0–13,820.0) | 0.59 |
Total eosinophil count (cells/mm3) | 21 (0–176) | 96 (0–246) | 0.31 |
Virus detected | 14 (53.8) | 102 (40.3) | 0.18 |
Values are presented as number (%) or median (interquartile range).
hs-CRP, high sensitivity C-reactive protein.
Variable | Infants with pathologic chest radiographic findings (n=26) | Infants with benign chest radiographic findings (n=253) | |
---|---|---|---|
Respiratory syncytial virus | 6 (23.1) | 57 (22.5) | 0.95 |
Human rhinovirus | 3 (11.5) | 12 (4.7) | 0.14 |
Metapneumovirus | 1 (3.8) | 7 (2.8) | 0.75 |
Adenovirus | 1 (3.8) | 5 (2.0) | 0.53 |
Parainfluenza virus | 2 (7.7) | 16 (6.3) | 0.78 |
Influenza A virus | 2 (7.7) | 6 (2.4) | 0.12 |
Influenza B virus | 0 (0) | 3 (1.2) | 0.58 |
Values are presented as number (%).
Variable | Parameter estimate | SE | |
---|---|---|---|
Male sex | −0.170 | 0.453 | 0.70 |
Age under 3 months | –0.432 | 0.736 | 0.55 |
Presence of fever prior to admission | 0.236 | 0.509 | 0.64 |
hs-CRP >0.3 mg/dL | 1.189 | 0.553 | 0.03 |
Past history of admission due to respiratory illness | 1.239 | 0.500 | 0.01 |
Independent variables for multivariate logistic regression analysis included sex (male), age (under 3 months), presence of fever prior to admission, hs-CRP (>0.3 mg/dL), and past history of admission due to respiratory illness.
SE, standard error; hs-CRP, high sensitivity C-reactive protein.