Chest Xrays in bronchiolitis
Date First Published:
December 12, 2008
Last Updated:
August 14, 2012
Report by:
Catherine Williams, ST5 Emergency Medicine (Royal Bolton Hospital )
Search checked by:
Tom Bartram, , Royal Bolton Hospital
Three-Part Question:
In [infants with bronchiolitis] is [chest xray] a useful investigation [to predict severity or alter management]
Clinical Scenario:
A 9 month old infant is brought to the Emergency Department by his mother with a 3 day history of coryzal symptoms and increasing difficulty breathing. Ausculation reveals widespread wheeze and crepitations, and you make a clinical diagnosis of bronchiolitis. You wonder whether a chest xray is indicated to confirm this diagnosis and assess its severity.
Search Strategy:
Medline 1950-March 2012 AND embase 1980- March 2012
Search Details:
(exp Bronchiolitis, viral/ OR exp Bronchiolitis/OR bronchiolit*.af OR RSV.af OR respiratory syncytial virus.af) AND (exp x-rays/OR xray.af OR x-ray.af OR radiograph*.af OR exp RADIOGRAPHY/ OR roentgenogram.af OR imaging.af) (Limit to: humans and (age groups all infant birth to 23 months) and English language).
Outcome:
Medline returned 368 results and Embase returned 2570 results of which eight unique papers directly addressing the BET question were identified.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Chest Xray appearances in Pneumonia and Bronchiolitis. Friis B, Eiken M, Hornsleth A, et al. 1990 Denmark | 128 children aged 1 month to 6 years admitted to hospital with suspected lower respiratory tract infection (bronchiolitis or pneumonia) CXR findings correlated with virology from NPA and bacteriology from nasotracheal secretions |
Observational study | x-ray Findings in virus positive (n=76) vs virus negative (n=52) patients irrespective of bacterial findings | 'Normal x-ray' 21% vs 8% p<0.05<br><br>'Bronchopneumonia' 18% vs. 6% p<0.05<br><br>‘Peribronchitis’: 25% vs 46% p<0.025<br><br>No significant difference in rate of lobar pneumonia, hyperinflation, atelectasis, hilar adenopathy. | Includes older children who fall outside the usual age range for bronchiolitis. Difficulties in obtaining secretions from lower airways for bacteriology |
| CXR findings in RSV +ve age <6 months vs >6 months | 'Lobar' pneumonia more common in <6 month (p<0.025) | ||||
| x-ray Findings of in patients with positive versus negative bacteriology | No significant difference | ||||
| Lobar pneumonia | Lobar pneumonia: (30%/21%/36%/37% NS), | ||||
| x-ray findings in patients with virus+/bact+, virus+/bact-, virus-/bact+& virus-/bact - | bronchopneumonia: (11%/26%/4%/7% NS), <br><br>interstitial pneumonia: (41%/18%/44%/30% NS)<br><br>Peribronchitis: (30%/21%/48%/44% NS)<br><br>Hyperinflation: (24%/15%/20%/11% NS)<br><br>Atelectasis: (5%/5%/20%/11% NS) | ||||
| Evaluation of the Utility of Radiography in Acute Bronchiolitis Schuh S, Lalani A, Allen U, et al Apr-07 Canada | 265 infants aged 2-23 months with typical bronchiolitis attending the emergency department<br><br>All patients had chest x-ray. Study appropriately powered |
Prospective Cohort Study. Rate of radiographic alternate diagnosis of patients with typical bronchiolitis | Xray inconsistent with bronchiolitis | 2 of 265 (0.75%) 95% CI 0-1.8 | Convenience sample- 665 patients not included as attended overnight- may indicated selection bias |
| Difference in admission rate pre and post radiography | Same in 258 0f 265 cases (97.4%) | ||||
| Correlation of clinical status vs. xray findings | Infants with sats >92% and RDAI score <10 more likely to have a simple radiograph (OR 3.9; 95% CI, 1.3-14.3) | ||||
| Rate of antibiotic prescription | Pre-x-ray 7/265 (2%)<br><br>Post-x-ray 39/265 (14.7%)<br><br>95% CI for difference in agreement 0.08 to 0.16 | ||||
| Chest radiographs in the pediatric emergency department for children (less than or equal to) 18 months of age with wheezing Mahabee-Gittens EM, Bachman D, Shapiro E, et al. 1999 USA | 270 children <18 months of age presenting to paediatric ED with wheeze on physical examination who had CXR performed. Excluded bronchopulmonary dysplasia, congenital heart disease, cystic fibrosis, FB inhalation. |
Retrospective chart review | Alternative diagnosis | 2/270 (0.7%) | Includes those with previous episodes of wheeze. Clinical data often incomplete. Not all children x-rayed (470 attendees, 270 x-rayed) hence probable selection bias. Reporting radiologist not blinded |
| Focal infiltrate on CXR versus clinical findings | History fever: OR 2.1 (p=0.03)<br><br>T>38.4 in ED: OR 2.5 (p=0.01)<br><br>Crackles on examination: OR 3.9 (p=0.0002)<br><br>(after bonferroni correction only crackles significant p<0.005) No significant correlation to Sa02 <93, RR>60, retractions or wheeze | ||||
| The Chest Radiograph in Acute Bronchiolitis Dawson K, Long A, Kennedy J, et al. 1990 New Zealand | 153 children <6 months of age, admitted to paediatric department with a clinical diagnosis of bronchiolitis | Retrospective study | Radiological severity determined by 2 blinded radiologists versus clinical severity score | No statistically significant relationship between radiological severity grading and clinical severity score | Retrospective study only included children who had x-ray as part of their routine management therefore may have selected those with more severe disease |
| Radiological findings in children with respiratory syncyctial virus infection: relationship to clinical and bacteriological findings. Eriksson J, Nordshus T, Carlsen KH, et al. 1986, Norway | 137 patients (0–48 months) with proven RSV infection underwent supine CXR and nasopharyngeal swab for bacteriology | Observational study | x-ray Changes in patients with positive vs negative nasopharyngeal swabs | 14 vs 4 p=0.01 | Inclusion criteria not clearly defined. 14 children clinically had URTI. Included children outside the age range from bronchiolitis. Clinical significance of positive nasopharyngeal bacteriology uncertain |
| Atelectasis | No significant difference | ||||
| Infiltrates | No significant difference | ||||
| Hyperinflation | No significant difference | ||||
| Hilar gland enlargement | No significant difference | ||||
| A cost effectiveness analysis of omitting radiography in diagnosis of acute bronchiolitis. Yong J, Schuh S, Rashidi R, et al. 2009 Canada | 265 previously healthy infants 2-23 months, presenting to an urban tertiary ED with ‘typical bronchiolitis’.<br><br>Pre-radiograph and post-radiograph ED diagnosis correlated with radiology report from blinded radiologist |
Prospective observational study and cost effectiveness analysis | Rate of alternative diagnosis | 2/265 (0.8%) | No attempt to correlate x-ray findings with microbiological results or disease severity. ‘Bronchiolitis associated pneumonia’ on x-ray unlikely to represent bacterial pneumonia in this cohort. Cost effectiveness analysis not generalisable to other healthcare systems |
| Sensitivity of ED physician for detection alternative diagnosis pre vs.post x-ray | 0% vs 0%<br><br>96% vs 88% | ||||
| Specificity of ED physician for detection alternative diagnosis pre and post x-ray | Pre-x-ray 12%<br><br>Post x-ray 41% | ||||
| Sensitivity of ED physician diagnosis of ‘bronchiolitis associated pneumonia’ | Pre-x-ray 90%<br><br>Post x-ray 83% | ||||
| Specificity for ‘bronchiolitis associated pneumonia’ | Pre-x-ray 90%<br><br>Post x-ray 83% | ||||
| Cost saving from omission of CXR | 53 Canadian dollars/patient | ||||
| First time wheezing in infants during respiratory syncytial virus season: chest radiograph findings. Farah M, Padgett L, McLario D, et al. 2002 USA | 140 healthy infants <12 months presenting with first episode of wheezing | Observational study | Rate of alternate diagnosis | 0.7% (cardiac abnormality) 16% | |
| Rate of infiltrate/atelectasis | Fever -35% | ||||
| Severity and symptoms in children with atelectasis | Tachypnoea- 52%<br><br>Hypoxaemia -39% | ||||
| Outpatient assessment of infants with bronchiolitis. Shaw K, Bell L, Sherman N. 1991 USA | 213 infants <13 months presenting to ED with bronchiolitis. Assessment of clinical and radiological features on initial presentation as predictors of more severe disease | Prospective observational study | Atelectasis on CXR as a predictor of severe disease | OR 2.7 (95% CI 0.97 to 3.70)<br><br>Sensitivity 21%<br><br>Specificity 97%<br><br>PPV 82%<br><br>NPV 70% | Disease severity dichotomised into ‘mild’ and ‘severe’. Radiologists blinded to clinical findings but investigators not blinded to CXR result |
Author Commentary:
Several of the studies include either older children or patients with previous episodes of wheezing and therefore may not be applicable to infants with bronchiolitis. Rate of alternative diagnosis in patients with typical bronchiolitis is low and in the majority of patients presenting with bronchiolitis x-ray is unlikely to influence management. Radiological changes do not correlate strongly with clinical severity. The studies by Friis et al (1990) and Eriksson et al (1986) also suggest that x-ray changes do not reliably differentiate patients with bacterial infection from those with viral infection. Overuse of chest radiography may increase the rate of false-positive diagnosis of ‘pneumonia’ and consequently unnecessary antibiotic use.
Bottom Line:
Routine chest radiography is not indicated in infants presenting with simple bronchiolitis
Level of Evidence:
Level 2: Studies considered were neither 1 or 3
References:
- Friis B, Eiken M, Hornsleth A, et al. . Chest Xray appearances in Pneumonia and Bronchiolitis.
- Schuh S, Lalani A, Allen U, et al. Evaluation of the Utility of Radiography in Acute Bronchiolitis
- Mahabee-Gittens EM, Bachman D, Shapiro E, et al. . Chest radiographs in the pediatric emergency department for children (less than or equal to) 18 months of age with wheezing
- Dawson K, Long A, Kennedy J, et al.. The Chest Radiograph in Acute Bronchiolitis
- Eriksson J, Nordshus T, Carlsen KH, et al.. Radiological findings in children with respiratory syncyctial virus infection: relationship to clinical and bacteriological findings.
- Yong J, Schuh S, Rashidi R, et al. . A cost effectiveness analysis of omitting radiography in diagnosis of acute bronchiolitis.
- Farah M, Padgett L, McLario D, et al.. First time wheezing in infants during respiratory syncytial virus season: chest radiograph findings.
- Shaw K, Bell L, Sherman N. . Outpatient assessment of infants with bronchiolitis.