Reliability of the chest radiograph in the diagnosis of lower respiratory infections in young children

[Chest ultrasonography in pediatric critical care practice]

An increasingly amount of evidence suggests that lung ultrasonography constitutes a relevant complementary diagnostic tool for adults patient in acute respiratory failure. A comprehensive and standardized ultrasonographic semiology has been described, relying on accurate and reproducible data directly obtained at patient's bedside. Therefore, pleural effusion, pneumothorax, pulmonary consolidation and interstitial lung disease can be diagnosed in a critical care environment with a similar level of performance than when reference diagnosis methods such as thoracic CT-scan are employed. Furthermore, lung ultrasonography seems to be able to contribute to an early therapeutic decision based on such online physiopathological data. Pioneers works in this field have suggested an attractive similarity between the ultrasonographic patterns described in adults and children. Nevertheless, the clinical usefulness of lung ultrasonographic approach in the pediatric critical care medicine still needs to be confirmed by specifically designed studies.

Chest radiography of acute paediatric lower respiratory infections: experience versus interobserver variation

AIM

To determine radiological and clinical chest radiographs (CRs) interpretation agreement in children with acute respiratory disease (ARD) versus clinical experience in multiple observers.

METHODS

Chest radiographs obtained in 70 consecutive children at the emergency department in 2010-2011 for ARD were reviewed. They were interpreted by 1-10 paediatric residents, three board-certified paediatricians (BCPs), three paediatric pulmonologists and one paediatric radiologist. Chest radiographs were analysed for presence of 10 radiological features and five diagnoses. A short clinical and laboratory context was given. Each child was given a clinical decision. Statistical analysis was by Fleiss' kappa for multiple observers.

RESULTS

Kappas by selected major diagnostic features and by observer experience were expressed relative to diagnosis by paediatric radiologist. Best agreements were for pleural effusion and pneumonia and worst for normal X-ray, hyperinflation and atelectasis. Years of experience were influential. Antibiotics for pneumonia diagnosed by radiologist would not have been prescribed in 23% of cases by residents, 25% by BCPs and 15% by pulmonologists.

CONCLUSION

In ARD in children, there is little interobserver agreement, especially among residents, which may impact on major clinical decision. There is a need to systematically train physicians in CRs reading.

The inter-observer variation of chest radiograph reading in acute lower respiratory tract infection among children

This study assessed the inter-observer agreement in the interpretation of several radiographic features in the chest radiographs (CXR) of 803 children aged 2-59 months with non-severe acute lower respiratory tract infection (ALRI). Inclusion criteria comprised: report of respiratory complaints, detection of lower respiratory findings, and presence of pulmonary infiltrate on the CXR taken on admission and read by the pediatrician on duty. Data on demographic and clinical findings on admission were collected from children included in a clinical trial on the use of amoxicillin (ClinicalTrials.gov Identifier NCT01200706). CXR was later read by two independent pediatric radiologists blinded to clinical information and pneumonia was finally diagnosed if there was agreement on the presence of pulmonary infiltrate or pleural effusion. The kappa index (κ) of agreement was calculated. The radiologists agreed that 774 (96.4%) and 3 (0.4%) CXR were appropriate or inappropriate for reading, respectively, and that 222 (28.7%) and 459 (59.3%) CXR presented or did not present pneumonia. In intent to treat analysis, that is, considering the 803 enrolled patients, κ for the presence of pneumonia was 0.725 (95% CI: 0.675-0.775). The overall agreement was 78.7% (normal CXR [n = 385, 60.9%], pneumonia [n = 222, 35.1%], other radiological diagnosis [n = 22, 3.5%], inappropriate for reading [n = 3, 0.5%]). The most frequent radiological findings were alveolar infiltrate (33.2%) and consolidation (32.9%) by radiologist 1 and consolidation (28.3%) and alveolar infiltrate (19.3%) by radiologist 2. Concordance for consolidation was 86.7% (k = 0.683, 95%CI: 0.631-0.741). Agreement was good between two pediatric radiologists when diagnosis of pneumonia among children with non-severe ALRI was compared.

Causes of recurrent pneumonia in children in a general hospital

AIM

Because the few previous studies on underlying causes of recurrent pneumonia in children have come from tertiary care referral centres where selection bias may be important, the aim of this study was to examine underlying causes of recurrent pneumonia in children in a general hospital.

METHODS

We performed a retrospective chart review in a general hospital of 62 children with recurrent pneumonia over a 7.5 years period.

RESULTS

In 19 patients (30.6%), no cause was identified, commonly because favourable natural history obviated the need for a full and invasive diagnostic work-up. Other underlying causes included recurrent aspiration in 16 patients (25.7%), lung disease (airway stenosis, bronchiectasis, middle lobe syndrome or tracheooesophageal fistula) in 10 patients (16.1%) and immune deficiency in 10 patients (16.1%). In contrast to previous studies, asthma was never diagnosed as an underlying cause, but diagnostic confusion between asthma (or recurrent upper respiratory tract infections) and recurrent pneumonia was common.

CONCLUSION

The cause of recurrent pneumonia in children remains elusive in almost a third of patients, partly because the favourable natural history consistent with immune system maturation eliminates the need for further diagnostic procedures. Asthma is more likely a differential diagnostic consideration than an underlying cause of recurrent pneumonia in children. A standardised diagnostic guideline is needed to improve knowledge on causes of recurrent pneumonia in children.

Evaluating the child with recurrent lower respiratory tract infections

We review the limited available evidence on underlying causes of recurrent pneumonia in children, supplemented by our own clinical experience. Diagnosing recurrent pneumonia in children is difficult. Diagnostic confusion is possible with recurrent upper respiratory tract infections and asthma. In our series of children with recurrent pneumonia, we never identified asthma as an underlying cause. Because the frequency or severity of recurrent pneumonia does not always justify additional invasive investigations, the diagnostic work-up may be incomplete in a number of cases. This may help to explain why an underlying cause for recurrent pneumonia cannot be found in approximately 30% of cases. Finally, the paradigm that recurrent pneumonia in the same lung lobe has a differential diagnosis different from those recurring in multiple lobes was not borne out in our case series. A stepwise and pragmatic approach to evaluating children with recurrent lower respiratory tract infections is recommended.

The role of lung ultrasound in the diagnosis and follow-up of community-acquired pneumonia

CAP may be diagnosed and followed up by lung sonography (LUS), a technique that shows excellent sensitivity and specificity that is at least comparable with that of chest X-ray in two planes. LUS may be performed with any abdomen-sonography device. Therefore, LUS is a readily available diagnostic tool that does not involve radiation exposure and has wide applications especially in situations where X-ray is not available and/or not applicable. An X-ray or CT of the chest should be performed in cases of negative lung sonography and if other differential diagnoses or complications are suspected.

The presence of radiological features on chest radiographs: how well do clinicians agree?

AIM

To compare levels of agreement amongst paediatric clinicians with those amongst consultant paediatric radiologists when interpreting chest radiographs (CXRs).

MATERIALS AND METHODS

Four paediatric radiologists used picture archiving and communication system (PACS) workstations to evaluate the presence of five radiological features of infection, independently in each of 30 CXRs. The radiographs were obtained over 1 year (2008) from children with fever and signs of respiratory distress, aged 6 months to <16 years. The same CXRs were interpreted a second time by the paediatric radiologists and by 21 clinicians with varying experience levels, using the Web 1000 viewing system and a projector. Intra- and interobserver agreement within groups, split by grade and specialty, were analysed using free-marginal multi-rater kappa.

RESULTS

Normal CXRs were identified consistently amongst all 25 participants. The four paediatric radiologists showed high levels of intraobserver agreement between methods (kappa scores between 0.53 and 1.00) and interobserver agreement for each method (kappa scores between 0.67 and 0.96 for PACS assessment). The 21 clinicians showed varying levels of agreement from 0.21 to 0.89.

CONCLUSION

Paediatric radiologists showed high levels of agreement for all features. In general, the clinicians had lower levels of agreement than the radiologists. This study highlights the need for improved training in interpreting CXRs for clinicians and the timely reporting of CXRs by radiologists to allow appropriate patient management.

Investigation into the effect of closed-system suctioning on the frequency of pediatric ventilator-associated pneumonia in a developing country

OBJECTIVE

To investigate the effect of closed-system vs. open endotracheal suctioning on the frequency of ventilator-associated pneumonia and outcome in a pediatric intensive care unit in a developing country.

DESIGN

Prospective observational and nonrandomized controlled clinical study.

SETTING

A 20-bed pediatric intensive care unit in a tertiary pediatric hospital.

PATIENTS

Infants and children mechanically ventilated for >24 hrs.

INTERVENTION

: Pediatric intensive care unit suctioning systems were alternated monthly. An 8-month interim analysis was planned with a priori efficacy and futility study termination boundaries set at p < .006 and p > .52, respectively.

MEASUREMENTS AND MAIN RESULTS

Demographic, clinical, and laboratory data were prospectively recorded. Ventilator-associated pneumonia was diagnosed using the Clinical Pulmonary Infection Score, and the results were confirmed retrospectively using Centers for Disease Control criteria. A total of 250 patients (median [interquartile range] age of 3.8 [1.2-15.0] months) in 263 pediatric intensive care unit admissions were included. Fifty-nine admissions developed ventilator-associated pneumonia, with a calculated rate of 45.1 infections per 1000 ventilated days. There was no difference in characteristics or outcome between patients on closed-system suctioning (n = 83) and those on open endotracheal suctioning (n = 180). The frequencies of ventilator-associated pneumonia for patients on closed-system suctioning and open endotracheal suctioning were 20.5% and 23.3%, respectively (p = .6), reaching the a priori set limit of futility. Patients who developed ventilator-associated pneumonia spent a median (interquartile range) of 22 (13-37) and 11 (8-16) days in the hospital and pediatric intensive care unit, respectively, compared to 14.5 (10-24) and 6 (4-8) days for those without ventilator-associated pneumonia (p < .001). A 22% proportion of patients who developed ventilator-associated pneumonia died compared to 11.3% of those without ventilator-associated pneumonia (p = .03). Risk factors for ventilator-associated pneumonia identified on multiple logistic regression were duration of mechanical ventilation, transport out of the pediatric intensive care unit, and blood transfusion.

CONCLUSION

Closed-system suctioning did not affect the frequency of ventilator-associated pneumonia or patient outcome in this setting.

The management of community-acquired pneumonia in infants and children older than 3 months of age: clinical practice guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America

Evidenced-based guidelines for management of infants and children with community-acquired pneumonia (CAP) were prepared by an expert panel comprising clinicians and investigators representing community pediatrics, public health, and the pediatric specialties of critical care, emergency medicine, hospital medicine, infectious diseases, pulmonology, and surgery. These guidelines are intended for use by primary care and subspecialty providers responsible for the management of otherwise healthy infants and children with CAP in both outpatient and inpatient settings. Site-of-care management, diagnosis, antimicrobial and adjunctive surgical therapy, and prevention are discussed. Areas that warrant future investigations are also highlighted.

Antibiotic availability and the prevalence of pediatric pneumonia during a physicians' strike

BACKGROUND

Antibiotics are widely believed to be overpre-scribed for pediatric respiratory infections, yet there are few data available on the effect of a sudden decrease in antibiotic availability on pediatric infectious disease.

OBJECTIVE

To determine whether the prevalence of radiographically diagnosed pneumonia changed over a period of decreased physician access and decreased antibiotic availability.

DESIGN

A retrospective study was performed which reviewed the number of pediatric respiratory antibiotic prescriptions over a period which included a physicians' strike. The study examined whether antibiotic availability had been affected by the strike. Pediatric chest radiograph reports were reviewed for the same period to determine whether changes in antibiotic availability had affected the prevalence of radiographically diagnosable pneumonias among children presenting to a pediatric emergency room.

RESULTS

While prescriptions for antibiotics fell by a minimum estimate of 28% during the strike, there was no change in the frequency of radiographic diagnoses of pneumonia.

CONCLUSIONS

Respiratory antibiotics appear to be available in the community in excess of the amount required to control pneumonia. A 28% decrease in antibiotic availability did not result in a significant increase in respiratory disease.

Intraobserver and interobserver agreement of the interpretation of pediatric chest radiographs

The objective of this study is to quantify the magnitude of intraobserver and interobserver agreement among physicians for the interpretation of pneumonia on pediatric chest radiographs. Chest radiographs that produced discordant interpretations between the emergency physician and the radiologist's final interpretation were identified for patients aged 1-4 years. From 24 radiographs, eight were randomly selected as study radiographs, and 16 were diversion films. Study participants included two pediatric radiologists, two senior emergency medicine physicians, and two junior fellowship-trained pediatric emergency medicine physicians. Each test included 12 radiographs: the eight study radiographs and four randomly interspersed diversion radiographs, and each radiograph was paired with a written clinical vignette. Testing was repeated on four occasions, separated by > or =2 weeks. The dependent variable was the interpretation of presence or absence of pneumonia; primary analysis done with Cohen's kappa (95% confidence intervals). Intraobserver agreement was good for pediatric radiologists (kappa = 0.87; 95% CI 0.60-0.99) for both but was lower for senior emergency physicians (mean kappa = 0.68; 95% CI 0.40-0.95) and junior pediatric emergency physicians (mean kappa = 0.62; 95% CI 0.35-0.98). Interobserver agreement was fair to moderate overall; between pediatric radiologists, kappa = 0.51 (0.39-0.64); between senior emergency physicians, kappa = 0.55 (0.41-69), and between junior pediatric emergency medicine physicians, kappa = 0.37 (0.25-0.51). Practicing emergency clinicians demonstrate considerable intraobserver and interobserver variability in the interpretation of pneumonia on pediatric chest radiographs.

Clinical predictors of pneumonia among children with wheezing

OBJECTIVE

The goal was to identify factors associated with radiographically confirmed pneumonia among children with wheezing in the emergency department (ED) setting.

METHODS

A prospective cohort study was performed with children <or=21 years of age who were evaluated in the ED, were found to have wheezing on examination, and had chest radiography performed because of possible pneumonia. Historical features and examination findings were collected by treating physicians before knowledge of the chest radiograph results. Chest radiographs were read independently by 2 blinded radiologists.

RESULTS

A total of 526 patients met the inclusion criteria; the median age was 1.9 years (interquartile range: 0.7-4.5 years), and 36% were hospitalized. A history of wheezing was present for 247 patients (47%). Twenty-six patients (4.9% [95% confidence interval [CI]: 3.3-7.3]) had radiographic pneumonia. History of fever at home (positive likelihood ratio [LR]: 1.39 [95% CI: 1.13-1.70]), history of abdominal pain (positive LR: 2.85 [95% CI: 1.08-7.54]), triage temperature of >or=38 degrees C (positive LR: 2.03 [95% CI: 1.34-3.07]), maximal temperature in the ED of >or=38 degrees C (positive LR: 1.92 [95% CI: 1.48-2.49]), and triage oxygen saturation of <92% (positive LR: 3.06 [95% CI: 1.15-8.16]) were associated with increased risk of pneumonia. Among afebrile children (temperature of <38 degrees C) with wheezing, the rate of pneumonia was very low (2.2% [95% CI: 1.0-4.7]).

CONCLUSIONS

Radiographic pneumonia among children with wheezing is uncommon. Historical and clinical factors may be used to determine the need for chest radiography for wheezing children. The routine use of chest radiography for children with wheezing but without fever should be discouraged.

Haemophilusinfluenzae type b conjugate vaccine for preventing pneumonia in infants hospitalized for bronchiolitis: a case-control study

BACKGROUND

Haemophilus influenzae type b (Hib) conjugate vaccine reduces the risk of pneumonia in infants.

OBJECTIVE

To determine the effect of Hib conjugate vaccine (HibCV) on the prevention of pneumonia as a complication among infants hospitalized for bronchiolitis.

METHODS

This record-based case-control study was conducted at The Children's Hospital "Dr. Ovidio Aliaga U" in La Paz, Bolivia during 2003 and 2004. Cases were infants hospitalized for bronchiolitis under 1 year of age who developed radiological pneumonia during hospitalization. Controls were patients who had good clinical progress without the use of antibiotics. Pneumonia was defined by alveolar consolidation on chest X-ray that justified the use of antibiotics.

RESULTS

Eighty patients were studied (16 cases and 64 controls). Their median age was 4.5 months. Demographic and clinical features were similar in both groups, except for a higher proportion of vomiting (56.3% vs. 28.1%; p<0.05) in the case group. The percentage of unvaccinated infants was significantly higher in cases (68.8% vs. 26.6%; p<0.05) and the length of hospital stay longer (8.5+/-5.4 vs. 3.1+/-2.2 days; p<0.05). There was a strong association between unvaccinated infants and the occurrence of pneumonia as a complication (odds ratio 6.1, 95% confidence interval 1.8-20.1; p<0.01).

CONCLUSIONS

Unvaccinated infants admitted for bronchiolitis have a higher risk of radiologically confirmed pneumonia. Larger studies are needed to validate these results and reconsider the burden of Hib infection among infants in less developed countries.

Pneumonia and other respiratory infections

Pneumonia is a leading killer of children in developing countries and results in significant morbidity worldwide. This article reviews the management of pneumonia and its complications from the perspective of both developed and resource-poor settings. In addition, evidence-based management of other respiratory infections, including tuberculosis, is discussed. Finally, the management of common complications of pneumonia is reviewed.

Pneumonia after implementation of the pneumococcal conjugate vaccine program in the province of Quebec, Canada

BACKGROUND

In Canada, a pneumococcal conjugate vaccine was licensed in 2001, and in the province of Quebec, a publicly-funded program was implemented for high-risk children in 2002, using a 4-dose schedule, and for all children in 2004, using a 3-dose schedule.

OBJECTIVES

To describe the epidemiology of hospitalized pneumonia in the population aged <5 years.

METHODOLOGY

Hospital discharge records with a main diagnosis of pneumonia, pleurisy, or empyema were analyzed regarding monthly frequencies by diagnostic categories, duration of stay, proportion of cases admitted to the intensive care unit, and case fatality.

RESULTS

Lobar pneumonia represented 32% of 25,319 all-cause pneumonia admissions during the period April 1997 to March 2006. Beginning in the spring of 2004, there was a marked decrease in the frequency of lobar pneumonia, whereas unspecified pneumonia tended to increase to a lesser extent. Compared with the pre-pneumococcal conjugate vaccine period, admissions for all-causes pneumonia decreased by 13% after program implementation and there was no increase in empyema cases.

CONCLUSIONS

Results are reassuring as to the effectiveness of the pneumococcal vaccination program in Quebec.

Evaluation of the lung in children with suspected pneumonia: usefulness of ultrasonography

PURPOSE

The authors sought to evaluate the sensitivity of chest ultrasound (US) versus chest radiography in detecting lung consolidation and pleural effusion in children with a clinical suspicion of pneumonia.

MATERIALS AND METHODS

Thirty-two chest radiographs and 32 chest US examinations were performed in 28 consecutive patients (aged 4 months to 17 years) with a clinical suspicion of pneumonia. Chest US examinations were carried out with a convex-array broadband probe (2-5 MHz) and a high-frequency linear-array broadband probe (5-12 MHz). The results obtained were compared with those of chest radiography.

RESULTS

Chest radiography identified subpleural consolidation in 22 patients, perihilar consolidation in 7, and pleural effusion in eight. In the same 22 patients, chest US showed 22 cases of subpleural consolidation but no cases of perihilar consolidation; pleural effusion was detected in 15 patients.

CONCLUSIONS

Chest US is capable of identifying subpleural consolidation with the same sensitivity as chest radiography and is highly accurate in demonstrating pleural effusion. For this reason, chest US may be a valuable aid and possible alternative to standard chest radiography in the evaluation and follow-up of children with suspected pneumonia.

Mycoplasma pneumoniae infection in a clinical setting

BACKGROUND

Mycoplasma pneumoniae infection predominantly affects the respiratory tract, although the other organs may also be involved. Previous studies compared the clinical features of patients with M. pneumonia pneumonia to other pathogens and these studies were predominantly adult case series rather than involving children. The objectives of the present study were to compare the clinical features, laboratory, and radiographic findings in children seropositive for M. pneumoniae infection with children tested for suspected M. pneumoniae infection who were seronegative.

METHODS

Using a retrospective review of children who had complement fixation test (CFT) performed for suspected M. pneumoniae infection, children were classified as seropositive if the acute phase serum titer was >or=64, or paired samples taken 2-4 weeks apart showed a fourfold or greater rise in serum titer. In contrast, a patient with an antibody titer <64 or with paired sera showing less than a fourfold rise in titer was considered seronegative.

RESULTS

One hundred and fifty-one children were included. Seventy-six children had serological evidence of M. pneumoniae infection and the remaining 75 were seronegative. Children with M. pneumoniae infection were more likely to have fever >6 days duration prior to admission, crackles on auscultation, radiographic consolidation and thrombocytosis at presentation. In addition, M. pneumoniae infection was associated with pneumonia whereas seronegative children were more likely to have upper respiratory tract infection or asthma.

CONCLUSIONS

Certain clinical parameters could assist in gauging the likelihood of M. pneumoniae infection in children, and thus direct whether antibiotic treatment is needed.

Inter-observer variability in chest radiograph reading for diagnosing acute lung injury in children

Acute lung injury (ALI), including its most serious form called acute respiratory distress syndrome (ARDS), is a devastating disease that can occur at any age. ALI/ARDS accounts for only 5-8% of admissions to pediatric intensive care units (PICUs) but is fatal in 30-60% of cases. International multicenter prospective studies are needed to better understand pediatric ALI/ARDS. However, a reproducible definition of ALI/ARDS is crucial to ensure that study populations are homogeneous. We designed a retrospective review to test the inter-observer variability of chest radiograph interpretation for presence of the American-European Consensus Conference (AECC) radiographic criterion for ALI/ARDS. The medical files of 24 children ventilated for ALI/ARDS in our PICU between January 1993 and December 2002 were reviewed. Five pediatric radiologists and five pediatric intensivists interpreted one frontal chest radiograph (FCR) per patient taken on the day of ALI/ARDS diagnosis. Each reader indicated whether the radiograph showed the AECC radiographic criterion for ALI/ARDS. Data analysis involved comparing each reader to all the others based on the raw agreement and Kappa coefficient (kappa). Features in the 24 patients were consistent with earlier studies. Global inter-observer agreement beyond chance was fair (kappa = 0.29 +/- 0.02) among the five radiologists (kappa = 0.26 +/- 0.05) and among the five intensivists (kappa = 0.29 +/- 0.05). Thus, considerable inter-observer variability occurred in assessing the radiographic criterion for ALI/ARDS, as previously shown in adults. Given the low incidence of ALI/ARDS in children, this variability may have a large impact in studies of pediatric ALI/ARDS.

Ultrasound diagnosis of pneumonia in children

PURPOSE

This study was done to compare the diagnostic accuracy of ultrasound and chest X-ray (CXR) in children with suspected pneumonia.

MATERIALS AND METHODS

Seventy-nine children aged from 6 months to 16 years with clinical signs suggestive of pneumonia underwent lung ultrasound and CXR.

RESULTS

Lung ultrasound was positive for the diagnosis of pneumonia in 60 patients, whereas CXR was positive in 53. In four patients with negative CXR and positive ultrasound findings, pneumonia was confirmed by chest computed tomography (CT) (performed for recurrent pneumonia in the same location). In the other three patients with negative CXR and positive ultrasound findings, the clinical course was consistent with pneumonia.

CONCLUSIONS

Lung ultrasound is a simple and reliable tool that can be used by the clinician in the case of suspected pneumonia. It is as reliable as CXR, can be easily repeated at the patient's bedside and carries no risk of irradiation.

Obliterative Bronchiolitis

Obliterative bronchiolitis (OB) is a condition characterized by inflammation and fibrosis of the bronchiolar walls resulting in narrowing or obliteration of the bronchiolar lumen. The most common causes are childhood lower respiratory tract infection, hematopoietic stem cell or lung and heart-lung transplantation, and toxic fume inhalation. The most frequent clinical manifestations are progressive dyspnea and dry cough. Pulmonary function tests demonstrate airflow obstruction and air trapping. Radiographic manifestations include reduction of the peripheral vascular markings, increased lung lucency, and overinflation. The chest radiograph, however, is often normal. High-resolution CT is currently the imaging modality of choice in the assessment of patients with suspected or proven OB. The characteristic findings on high-resolution CT consist of areas of decreased attenuation and vascularity (mosaic perfusion pattern) on inspiratory scans and air trapping on expiratory scans. Other CT findings of OB include bronchiectasis and bronchiolectasis, bronchial wall thickening, small centrilobular nodules, and three-in-bud opacities. Recent studies suggest that hyperpolarized ³He-enhanced magnetic resonance imaging may allow earlier recognition of obstructive airway disease and therefore may be useful in the diagnosis and follow-up of patients with OB.

The evolving approach to the young child who has fever and no obvious source

Fever is a common complaint of young children who seek care in the emergency department. Recent advances, such as universal vaccination with the pneumococcal conjugate vaccine, require the review of traditional approaches to these patients. This article discusses newer strategies in the evaluation and management of the young child with fever, incorporating changes based on the shifting epidemiology of bacterial infection.

Atelectatic children treated with intrapulmonary percussive ventilation via a face mask: clinical trial and literature overview

BACKGROUND

Persistent atelectasis in children is lacking a gold standard treatment. Intrapulmonary percussive ventilation (IPV) is presented as a promising chest physiotherapy technique in the treatment of atelectasis. This study aimed to follow the evolution of atelectasis resolution with noninvasive IPV in young children and to detect eventual adverse effects.

METHODS

Six children were hospitalized for respiratory distress with suspicion of atelectasis. A 15 min IPV treatment was immediately started at D1 twice a day for 5 days. Children were free of any other treatment. Chest X-Ray (CXR) was performed on the second day (D2) and was repeated 3 days later (D5). After the study, CXR were retrospectively reviewed by three specialists who had no knowledge of the clinical observations of the patients. They were asked to assess atelectasis by a score between 4 (complete collapse) and 0 (complete resolution). A clinical score on a maximum of 4 points was assessed by appetite deterioration, dyspnoea, mucus production and cough presence at D1 and D5 (1 point per symptom present). Paired t-test compared D1 and D5 results.

RESULTS

All patients returned home after 5 days IPV. SpO2 normalized (93.2 +/- 0.8 to 95.3 +/- 0.8; P = 0.002) and patients all improved clinically (score, 2.8 +/- 0.9 to 0.8 +/- 0.6; P < 0.05). Out of four patients with radiographic evidence of atelectasis, three improved their atelectasis score.

CONCLUSIONS

No side-effect or adverse effect was observed during IPV treatments. IPV was safe and effective in atelectasis resolution in 3/4 of the cases. Patients all recovered a stable clinical state. CXR improved in 4/5 children. They were all discharged home after 5 days of IPV treatment.

Effectiveness of Haemophilus influenzae type B conjugate vaccine on prevention of pneumonia and meningitis in Bangladeshi children: a case-control study

BACKGROUND

Few Asian countries have introduced Haemophilus influenzae type b (Hib) conjugate vaccine because of its cost and uncertainty regarding disease burden.

METHODS

To estimate the effectiveness of Hib conjugate vaccine in preventing pneumonia and meningitis in children age <2 years, an incident case-control study was conducted in a birth cohort of about 68,000 infants in Dhaka city, Bangladesh. DPT vaccine was systematically replaced by a combined Hib-DPT vaccine in selected immunization centers of the study area. Four matched community- and 2 hospital-controls were randomly selected for each confirmed case of pneumonia and meningitis from the study area.

RESULTS

About 35% of the infants received each of the 3 doses of Hib-DPT vaccine. There were 2679 children who had a chest roentgenogram. For 475 children, a radiologist and a pediatrician independently identified substantial alveolar consolidation. Following at least 2 doses of Hib vaccine, the preventable fractions [95% confidence intervals (CI)] using community and hospital controls were 17% (-10% to 38%) and 35% (13% to 52%) respectively. Of these 475 cases, 2 radiologists with the World Health Organization concurred with the findings for 343 patients, yielding preventable fractions of 34% (6% to 53%) and 44% (20% to 61%). Fifteen confirmed Hib meningitis cases were identified; the preventable fractions (95% CI) using community and hospital controls, respectively, were 89% (28% to 100%) and 93% (53% to 100%).

CONCLUSIONS

The study documented that significant fractions of pneumonia and meningitis in Bangladeshi children age <2 years can be prevented by the Hib conjugate vaccine.

Effective treatment strategies for paediatric community-acquired pneumonia

Pneumonia is the leading cause of death in children under 5 years of age worldwide and a cause of morbidity in a considerable number of children. A number of studies have sought to identify the ideal choice of antibiotics, route of administration and optimum duration of treatment based on the most likely aetiological agents. Emerging bacterial resistance to antibiotics is also an important consideration in treatment. However, inconsistent clinical and radiological definitions of pneumonia make comparison between studies difficult. There is also a lack of well designed adequately powered randomised controlled trials. This review describes the difficulties encountered in diagnosing community-acquired pneumonia, aetiology, treatment strategies with recommendations and highlights areas for further research.

Effectiveness of heptavalent pneumococcal conjugate vaccine in children younger than 5 years of age for prevention of pneumonia: updated analysis using World Health Organization standardized interpretation of chest radiographs

BACKGROUND

A World Health Organization (WHO) working group in 2001 developed a method for standardizing interpretation of chest radiographs in children for epidemiologic purposes. We reevaluated radiographs from the Kaiser Permanente Pneumococcal Efficacy trial using this method.

METHODS

Seven-valent pneumococcal conjugate vaccine was evaluated in a randomized, controlled study including 37,868 infants. Effectiveness against pneumonia was previously evaluated using the original treating radiologist reading. There were 2841 sets of radiographs from this trial and all available radiographs were scanned and read blindly by 2 WHO crosstrained readers (A and B); discordance between the 2 primary readers was resolved through a consensus reading by an adjudicating panel of 2 radiologists.

RESULTS

Of the 2841 radiographs, 2446 were available for scanning and were reviewed using WHO-defined descriptive categories. Two hundred fifty of the 2446 radiographs were read as positive by both readers. An additional 129 were read as positive by reader A only and 142 by reader B only for a total of 521 radiographs that were read as positive by one or both of the reviewers. The concordance rate between the 2 reviewers was 250 of 521 (48%). Of the 271 discordant radiographs, 45 of 129 (34.9%) of reader A and 66 of 142 (46.5%) for reader B were finalized as positive by the adjudicating panel. Overall, 361 radiographs were finalized as positive (12.7%). With these 361 images as the standard, the sensitivity and specificity of reader A were 82% and 97%, respectively, and for reader B, 88% and 97%, respectively. Kappa between the 2 readers was 0.58. Of 25 control radiographs read as positive by both A and B, 80% were also read as positive by the panel and all 25 control negative radiographs were read as negative by the panel. Using original readings by point-of-care radiologists, efficacy against first episode of radiograph confirmed pneumonia was 17.7% (95% confidence interval [CI] = 4.8-28.9%) in intent-to-treat and 20.5% (95% CI = 4.4-34%) in per protocol. Using the WHO method, the efficacy against first episode of radiograph confirmed pneumonia adjusting for age, gender and year of vaccination of 25.5% (95% CI = 6.5-40.7%, P = 0.011) for intent-to-treat and 30.3% (95% CI = 10.7-45.7%, P = 0.0043) for per protocol.

CONCLUSION

Using WHO criteria for reading of radiographs increased point estimates of vaccine efficacy presumably as a result of improved specificity.

Viral pneumonia in children

Viral pneumonia causes a heavy burden on our society. In the United States, more than one million cases of pneumonias afflict children under the age of 5 years, costing hundreds of millions of dollars annually. The majority of these infections are caused by a handful of common viruses. Knowledge of the epidemiology of these viruses combined with new rapid diagnostic techniques will provide faster and more, reliable diagnoses in the future. Although the basic clinical epidemiology of these viruses has been carefully investigated over the last 30 years, new molecular techniques are greatly expanding our understanding of these agents and the diseases they cause. Antigenic and genetic variations are being discovered in many viruses previously thought to be homogeneous. The exact roles and the biological significance of these variations are just beginning to be explored, but already evidence of differences in pathogenicity and immunogenicity has been found in many of these substrains. All of this information clearly will impact the development of future vaccines and antiviral drugs. Effective drugs exist for prophylaxis against influenza A and respiratory syncytial virus, and specific therapy exists for influenza A. Ribarivin is approved for use in respiratory synctial virus infections, and it alone or in combination with other agents (eg, IGIV) may be effective in immunocompromised patients, either in preventing the development of pneumonia or in decreasing morbidity and mortality. Many new antiviral agents are being tested and developed, and several are in clinical trials.

Antibiotics in childhood pneumonia

Pneumonia is one of the most common global childhood illnesses. The diagnosis relies on a combination of clinical judgement and radiological and laboratory investigations. Streptococcus pneumoniae remains the most important cause of childhood community-acquired pneumonia. In addition, viruses (including respiratory syncytial virus) and atypical bacteria (Mycoplasma and Chlamydia) are likely pathogens in younger and older children in developed countries. In the minority of cases only, the actual organism is isolated to guide treatment. Antibiotics effective against the expected bacterial pathogens should be instituted where necessary. The route and duration of antibiotic therapy, the role of emerging pathogens and the impact of pneumococcal resistance and conjugate pneumococcal vaccines are also discussed.

Bacterial pneumonia vaccines and childhood pneumonia: are we winning, refining, or redefining?

Bacterial pneumonia is a substantial cause of childhood morbidity and mortality worldwide, but determination of pathogen-specific burden remains a challenge. In less developed settings, the WHO recommended guidelines are useful for initiating care, but are non-specific. Blood culture has low sensitivity, while radiological findings are non-specific and do not discriminate between viral and bacterial causes of pneumonia. In vaccine probe studies, efficacy is dependent on the specificity of the study outcome to detect pneumonia and the impact of the vaccine on the selected outcome, and may underestimate the true burden of bacterial pneumonia. The rising incidence of antibiotic resistance, emerging respiratory pathogens, potential replacement pneumococcal disease following widespread introduction of pneumococcal polysaccharide-protein conjugate vaccine, the limited specificity of chest radiography, and the poor sensitivity of blood culture are substantial obstacles to accurate surveillance. We provide an overview of the diagnostic challenges of bacterial pneumonia and highlight the need for refining the current diagnostic approach to ensure adequate epidemiological surveillance of childhood pneumonia and the success, or otherwise, of any immunisation strategies.

Fever without source in children 0 to 36 months of age

Although fever in the young child (0-36 months) is a common clinical problem, the evaluation and treatment of febrile children remain controversial. Furthermore, universal vaccination with the heptavalent pneumococcal conjugate vaccine (PCV7) has changed the epidemiology of invasive bacterial disease in young children. This article addresses the approach to febrile neonates (0-28 days old), young infants (1-3 months old), and older infants and toddlers (3-36 months old) in the PCV7 era.

Identifying children with pneumonia in the emergency department

Emergency physicians need to clinically differentiate children with and without radiographic evidence of pneumonia. In this prospective cohort study of 510 patients 2 to 59 months of age presenting with symptoms of lower respiratory tract infection, 100% were evaluated with chest radiography and 44 (8.6%) had pneumonia on chest radiography. With use of multivariate analysis, the adjusted odds ratio (AOR) and 95% confidence intervals (CI) of the clinical findings significantly associated with focal infiltrates were age older than 12 months (AOR 1.4, CI 1.1-1.9), RR 50 or greater (AOR 3.5, CI 1.6-7.5), oxygen saturation 96% or less (AOR 4.6, CI 2.3-9.2), and nasal flaring (AOR 2.2 CI 1.2-4.0) in patients 12 months of age or younger. The combination of age older than 12 months, RR 50 or greater, oxygen saturation 96% or less, and in children under age 12 months, nasal flaring, can be used in determining which young children with lower respiratory tract infection symptoms have radiographic pneumonia.

[Chest radiograph in bronchiolitis: is it always necessary?]

BACKGROUND

The routine use of chest radiograph in infants with bronchiolitis increases health costs and can often unnecessarily expose the patient to radiation.

OBJECTIVES

To evaluate the prevalence of infiltrate/atelectasis in infants younger than 2 years who presented to the emergency department with bronchiolitis, to assess whether patient management is changed after viewing the chest radiograph and to determine which clinical variables can accurately identify children with normal radiographs, with a view to reducing unnecessary radiological investigations.

PATIENTS AND METHODS

From October 2003 to December 2004, infants aged < 24 months evaluated in the emergency department of the Severo Ochoa Hospital (Madrid) with a diagnosis of bronchiolitis were included in this study. The variables registered were age, sex, time since onset, respiratory rate, temperature, asymmetry on auscultation, oxygen saturation and the virus identified. A chest radiograph was obtained and the need for admission was evaluated before and after obtaining the results.

RESULTS

Two hundred fifty-two infants were included, of which 50 % were aged less than 5 months. Infiltrate/atelectasis was identified in 14.3 % (95 % CI: 10.1-18.5; kappa coefficient: 0.64). Patients with infiltrate/atelectasis were 2.5 times more likely to have a temperature of > or = 38 degrees C (p: 0.004), O2 saturation of < 94 % (p: 0,006) and to be admitted before the results of chest radiograph were known. No differences were found between children with and without infiltrate in age at presentation, sex, disease duration, respiratory rate or identified virus. Patient management was modified in 30 % of patients with infiltrate/ atelectasis. Patients with a temperature of < 38 degrees and O2 saturation of > 94 % had a 92 % probability of normal chest radiograph.

CONCLUSIONS

Most infants presenting with bronchiolitis had a normal chest radiograph. Temperature >or = 38 degrees and O2 saturation < 94 % were significantly associated with infiltrate/atelectasis. In most infants with bronchiolitis, the absence of fever and hypoxia are good predictors of normal chest radiographs.

Human metapneumovirus: a new player among respiratory viruses

The human metapneumovirus (hMPV) is a newly described member of the Paramyxoviridae family belonging to the Metapneumovirus genus. Since its initial description in 2001, hMPV has been reported in most parts of the world and isolated from the respiratory tract of subjects from all age groups. Despite the fact that prospective and case-control studies have been limited, the epidemiology and clinical manifestations associated with hMPV have been found to be reminiscent of those of the human respiratory syncytial virus, with most severe respiratory tract infections occurring in infants, elderly subjects, and immunocompromised hosts. Additional research is needed to define the pathogenesis of this viral infection and the host's specific immune response.

[Usefulness of physical examination at a primary health centre to diagnose infant pneumonia caught in the community]

OBJECTIVE

To determine the diagnostic usefulness of three clinical signs (temperature, cough, crepitant stertor) for diagnosing pneumonia in children. To evaluate the agreement of two radiologists in evaluating thoracic x-rays (TXR).

DESIGN

Study of diagnostic tests.

SETTING

Primary care.

PARTICIPANTS

350 clinical histories of children who had an urgent TXR to diagnosis pneumonia between 1st January 1996 and 30th June 1999.

MAIN MEASUREMENTS

a) Prevalence of pneumonia in the entire sample and two age-based sub-groups: aged 5 years and under, and over 5; b) positive probability quotients (PQ+) and negative ones (PQ-) and 95% confidence intervals (95% CI). The TXR was seen as the reference standard, and c) kappa index (kappa) for inter-radiologist concordance.

RESULTS

Prevalence: the entire sample, 22.9% (95% CI, 18.5-27.3); children aged 5 or less, 20.4% (95% CI, 15.6-25.2); aged over 5, 31.3% (95% CI, 21.1-41.4). The signs studied were only of any use in confirming the diagnosis in children over 5: PQ+ was 3.52 (1.28-9.69). Radiologists coincided in their diagnosis in 93.1% of the TXR (kappa=0.8; 95% CI, 0.77-0.83).

CONCLUSIONS

This study did not prove that there was a sub-grouping of clinical signs which confirmed unmistakably the diagnosis of pneumonia in children.

Hindsight judgement on ambiguous episodes of suspected infection in critically ill children: poor consensus amongst experts?

Few episodes of suspected infection observed in paediatric intensive care are classifiable without ambiguity by a priori defined criteria. Most require additional expert judgement. Recently, we observed a high variability in antibiotic prescription rates, not explained by the patients' clinical data or underlying diseases. We hypothesised that the disagreement of experts in adjudication of episodes of suspected infection could be one of the potential causes for this variability. During a 5-month period, we included all patients of a 19-bed multidisciplinary, tertiary, neonatal and paediatric intensive care unit, in whom infection was clinically suspected and antibiotics were prescribed ( n=183). Three experts (two senior ICU physicians and a specialist in infectious diseases) were provided with all patient data, laboratory and microbiological findings. All experts classified episodes according to a priori defined criteria into: proven sepsis, probable sepsis (negative cultures), localised infection and no infection. Episodes of proven viral infection and incomplete data sets were excluded. Of the remaining 167 episodes, 48 were classifiable by a priori criteria ( n=28 proven sepsis, n= 20 no infection). The three experts only achieved limited agreement beyond chance in the remaining 119 episodes (kappa = 0.32, and kappa = 0.19 amongst the ICU physicians). The kappa is a measure of the degree of agreement beyond what would be expected by chance alone, with 0 indicating the chance result and 1 indicating perfect agreement.

CONCLUSION

agreement of specialists in hindsight adjudication of episodes of suspected infection is of questionable reliability.

Community-acquired pneumonia in children

Community acquired pneumonia (CAP) is common in childhood. Viruses account for most cases of CAP during the first two years of life. After this period, bacteria such as Streptococcus pneumoniae, Mycoplasma pneumoniae and Chlamydia pneumoniae become more frequent. CAP symptoms are nonspecific in younger infants, but cough and tachypnea are usually present in older children. Chest x-ray is useful for confirming the diagnosis. Most children can be managed empirically with oral antibiotics as outpatients without specific laboratory investigations. Those with severe infections or with persistent or worsening symptoms need more intensive investigations and may need admission to hospital. The choice and dosage of antibiotics should be based on the age of the patient, severity of the pneumonia and knowledge of local antimicrobial resistance patterns. The Canadian Paediatric Society recommends the use of the heptavalent conjugate pneumococcal vaccine, which is efficacious in reducing chest x-ray positive pneumonia by up to 20%.

Serum Concentrations of Pneumococcal Anticapsular Antibodies in Children with Pneumonia Associated with Streptococcus pneumonia Infection

The levels of specific IgG antibody to pneumococcal capsular polysaccharides were investigated in 182 children, aged 2-5 years, who were hospitalized for community-acquired pneumonia, including 55 (30.2%) with evidence of acute pneumococcal infection. Results show that children with concentrations of specific IgG antibody that would protect against invasive disease do not seem to be protected against pneumonia associated with pneumococcal infection.

Pneumonia in term neonates: laboratory studies and duration of antibiotic therapy

OBJECTIVES

To compare 2 days of antibiotic therapy (AT) to 4 days of AT in neonates with pneumonia and to assess the usefulness of neutrophil values (NV), C-reactive protein (CRP), and procalcitonin (PCT) in this population.

DESIGN

The study population consisted of consecutive, eligible term neonates begun on AT for suspected pneumonia. Of 51 neonates, 26 qualified for randomization (14, 2-day group; 12, 4-day group). NV were obtained with the initial evaluation and 12 and 24 hours later. CRP and PCT were obtained 12 and 48 hours after the initial evaluation.

RESULTS

None of the 12 neonates in the 4-day group developed recurrent respiratory symptoms. Three of the 14 neonates randomized to the 2-day group had recurrence of symptoms, resulting in study termination. NV, CRP, and PCT were similar in the 2- and 4-day groups. In the three neonates who developed respiratory symptoms, all absolute total neutrophil values and five out of nine absolute total immature neutrophil values were abnormal. However, all immature:total neutrophil values were normal, and CRP was strikingly elevated in only one neonate; only one of six PCT values was abnormal. In a secondary analysis of all 51 study neonates, CRP and PCT did not provide additional benefit over NV in differentiating neonates with pneumonia.

CONCLUSIONS

Four days of AT appears to be adequate for selected term neonates with pneumonia; however, 2 days of AT appears to be inadequate for this population. Relative to NV, CRP and PCT appear to have a limited role.

Parainfluenza viruses

Human parainfluenza viruses (HPIV) were first discovered in the late 1950s. Over the last decade, considerable knowledge about their molecular structure and function has been accumulated. This has led to significant changes in both the nomenclature and taxonomic relationships of these viruses. HPIV is genetically and antigenically divided into types 1 to 4. Further major subtypes of HPIV-4 (A and B) and subgroups/genotypes of HPIV-1 and HPIV-3 have been described. HPIV-1 to HPIV-3 are major causes of lower respiratory infections in infants, young children, the immunocompromised, the chronically ill, and the elderly. Each subtype can cause somewhat unique clinical diseases in different hosts. HPIV are enveloped and of medium size (150 to 250 nm), and their RNA genome is in the negative sense. These viruses belong to the Paramyxoviridae family, one of the largest and most rapidly growing groups of viruses causing significant human and veterinary disease. HPIV are closely related to recently discovered megamyxoviruses (Hendra and Nipah viruses) and metapneumovirus.

Pneumonitis associated with Ureaplasma urealyticum in children with cancer

We describe 3 pediatric patients with cancer who had clinical and radiographic evidence of pneumonitis and for whom cultures of bronchoalveolar lavage fluid specimens yielded Ureaplasma urealyticum. Two of the patients died; for the surviving patient, clinical improvement coincided temporally with administration of erythromycin. Immunocompromised patients with pneumonitis of unclear etiology should have respiratory secretions cultured for mycoplasmas and should receive empiric therapy that includes a macrolide antibiotic.

Characteristics of Streptococcus pneumoniae and atypical bacterial infections in children 2-5 years of age with community-acquired pneumonia

The characteristics of community-acquired pneumonia associated with Streptococcus pneumoniae infection were compared with those associated with atypical bacterial infection and with mixed S. pneumoniae-atypical bacterial infection in 196 children aged 2-5 years. S. pneumoniae infections were diagnosed in 48 patients (24.5%); atypical bacterial infections, in 46 (23.5%); and mixed infections, in 16 (8.2%). Although white blood cell counts and C-reactive protein levels were higher in patients with pneumococcal infections, no other clinical, laboratory, or radiographic characteristic was significantly correlated with the different etiologic diagnoses. There was no significant difference in the efficacy of the different treatment regimens followed by children with S. pneumoniae infection, whereas clinical failure occurred significantly more frequently among children with atypical bacterial or mixed infection who were not treated with a macrolide. This study shows the major role of both S. pneumoniae and atypical bacteria in the development of community-acquired pneumonia in young children, the limited role of clinical, laboratory, and radiological features in predicting etiology, and the importance of the use of adequate antimicrobial agents for treatment.

Management of community-acquired pediatric pneumonia in an era of increasing antibiotic resistance and conjugate vaccines

The antibiotic management of infants and children with pneumonia is based on the clinician's assessment of the most likely infecting pathogens, the susceptibilities of the infecting pathogens and the seriousness of the illness. The bacterial etiology of pneumonia changed significantly following the universal use of protein-conjugated vaccines for Haemophilus influenzae type b. Similar significant changes are likely to occur with universal use of protein-conjugated vaccines for Streptococcus pneumoniae, requiring the clinician to alter assumptions of the risk of invasive bacterial infection in the child who presents with pneumonia. New strategies are likely to require fewer ancillary tests (e.g. white blood cell count, C-reactive protein and blood culture) and suggest a decreased need for empiric antibiotic therapy. Although the majority of lower respiratory tract infections in children have a viral etiology and are not amenable to antibiotic therapy, for the seriously ill child who is thought to be likely to have pneumonia caused by a bacterial pathogen, recent changes in the susceptibility patterns of both common organisms such as S. pneumoniae and more unusual pulmonary pathogens such as Staphylococcus aureus have forced changes in the selection of both empiric and definitive antibiotic therapy. Third generation cephalosporins ceftriaxone and cefotaxime appear to be effective therapy for pneumonia caused by virtually all current isolates of S. pneumoniae. In contrast antibiotic regimens for life-threatening pulmonary infections in which Staphylococcus aureus is a suspected pathogen should include vancomycin.