Dr. Simon BensonGP Specialist Trainee

IntroductionDiagnosis of pneumonia in children with

wheeze is difficultLimited data exists regarding predictors of

pneumonia among children with wheezeAsthma and bronchiolitis are two of the

commonest presentations to ED – difficult to distinguish these from those with pneumonia

Result is unnecessary chest radiographs (CXR)

ObjectivesInvestigate value of historical features

andclinical findings in patients with wheeze on examination for whom a CXR was ordered

To develop a clinical decision rule for the use of CXR in this patient population

Study DesignProspective cohortInclusion criteria

Children less than 21 years old Wheezing on examination CXR performed Attending ED between 01/10/2006 and 30/10/2007 Attending Children’s Hospital Boston, Boston MA,

USA

Study DesignExclusion criteria

Chronic respiratory illnesses (eg cystic fibrosis) Illnesses that may predispose to pneumonia

(congenital heart disease, sickle cell anaemia, immunosuppression, malignancy)

Other potential causes for wheeze elicited on history (eg trauma or foreign body aspiration)

Study DesignDoctors were orientated to study and

reminded monthlyQuestionnaire completed prior to CXR request

Specific historical features (eg cough, fever, wheeze, chest pain)

Examination findings Level of respiratory distress Reason for requesting CXR Response to inhaled bronchodilators

Some basic observations were also recorded (Temp, RR, oxygen saturations)

Study DesignCXRs were read by two blinded

radiographersAsked to decide whether normal or abnormalIf abnormal were findings more or less likely

to be caused by atelectasis or pneumoniaIf they failed to agree – original report used

as final diagnosis.

Control group used to assess sample bias was drawn from all patients receiving CXR for first 3 days of each month

Results540 patients included initially

14 excluded due to chronic illness

526 patients included in the study 59% were male Median age 1.9 years (IQ range 0.7-4.5)

47% of patients had a past medical history of wheeze

15% received antibiotics

5% patients were diagnosed with pneumonia

Results81% patients with pneumonia had a history of

fever73% patients with pneumonia had temp > 38.0

in ED Compared to 38% without

Those patients presenting with a fever or history of a fever had were twice as likely to have pneumonia but this increased to nearly five times more likely if a temperature of over 39.0 was recorded in ED

All these results are significant

ConclusionRadiographic pneumonia in children with

wheeze is uncommonHistorical and clinical features may be used

to determine the suitability of CXR in a patient presenting with wheeze

Routine use of CXR for children with wheezing but without fever should be discouraged.

DiscussionIncludes children with asthmaSupports previous workIncluded children up to age 21 – extrapolation by

age group is very difficult – anatomy and physiology vastly different at each end of spectrum

Busy emergency department – how many lost patients (estimated at 39% of all eligible patients)

CXR ordered at discretion of the doctor not according to predefined criteria (introduces selection bias)

DiscussionDid not include outcomes for children with

wheeze who did not have a CXR – can not generalise to all children with wheeze

Likely overestimation of rate of pneumonia in wheeze

Viral versus bacterialSome disagreement between radiologists did

occur – could have used WHO guidelines for radiographic diagnosis of pneumonia but this may not apply with wheezing because of the presence of atelectasis

Final ThoughtsGenerally good paperGenerally good quality and reliable resultsEnables a solid evidence based conclusion to

be drawn that is:Routine use of CXR for children with wheezing

but without fever should be discouraged.