Inter- and intra-observer variability in the assessment of atelectasis and consolidation in neonatal chest radiographs

Associating a standardized reporting tool for chest radiographs with clinical complications in pediatric acute chest syndrome

BACKGROUND

Acute chest syndrome (ACS) is an important cause of morbidity in sickle cell disease (SCD). A standardized tool for reporting chest radiographs in pediatric SCD patients did not previously exist.

OBJECTIVE

To analyze the interobserver agreement among pediatric radiologists' interpretations for pediatric ACS chest radiographs utilizing a standardized reporting tool. We also explored the association of radiographic findings with ACS complications.

METHODS

This was a retrospective cohort study of pediatric ACS admissions from a single institution in 2019. ICD-10 codes identified 127 ACS admissions. Two radiologists independently interpreted the chest radiographs utilizing a standardized reporting tool, a third radiologist adjudicated discrepancies, and κ analysis assessed interobserver agreement. Clinical outcomes were correlated with chest radiograph findings utilizing Pearsons' χ2 , t tests, and Mann-Whitney U tests. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.

RESULTS

Interobserver agreement was moderate to near-perfect across variables, with κ analysis showing near-perfect agreement for opacity reported in the right upper lobe (0.84), substantial agreement for right lower lobe (0.63), and vertebral bony changes (0.72), with moderate agreement for all other reported variables. On the initial chest radiograph, an opacity located in the left lower lobe (LLL) correlated with pediatric intensive care unit transfer (p = .03). Pleural effusion on the initial chest radiograph had a 3.98 OR (95% CI: 1.35-11.74) of requiring blood products and a 10.67 OR (95% CI: 3.62-31.39) for noninvasive ventilation.

CONCLUSION

The standardized reporting tool showed moderate to near-perfect agreement between radiologists. LLL opacity, and pleural effusion were associated with increased risk of ACS complications.

Improving reference standards for validation of AI-based radiography

Objective:

Demonstrate the importance of combining multiple readers' opinions, in a context-aware manner, when establishing the reference standard for validation of artificial intelligence (AI) applications for, e.g. chest radiographs. By comparing individual readers, majority vote of a panel, and panel-based discussion, we identify methods which maximize interobserver agreement and label reproducibility.

Methods:

1100 frontal chest radiographs were evaluated for 6 findings: airspace opacity, cardiomegaly, pulmonary edema, fracture, nodules, and pneumothorax. Each image was reviewed by six radiologists, first individually and then via asynchronous adjudication (web-based discussion) in two panels of three readers to resolve disagreements within each panel. We quantified the reproducibility of each method by measuring interreader agreement.

Results:

Panel-based majority vote improved agreement relative to individual readers for all findings. Most disagreements were resolved with two rounds of adjudication, which further improved reproducibility for some findings, particularly reducing misses. Improvements varied across finding categories, with adjudication improving agreement for cardiomegaly, fractures, and pneumothorax.

Conclusion:

The likelihood of interreader agreement, even within panels of US board-certified radiologists, must be considered before reads can be used as a reference standard for validation of proposed AI tools. Agreement and, by extension, reproducibility can be improved by applying majority vote, maximum sensitivity, or asynchronous adjudication for different findings, which supports the development of higher quality clinical research.

Advances in knowledge:

A panel of three experts is a common technique for establishing reference standards when ground truth is not available for use in AI validation. The manner in which differing opinions are resolved is shown to be important, and has not been previously explored.

Impact of four different recumbencies on the distribution of ventilation in conscious or anaesthetized spontaneously breathing beagle dogs: An electrical impedance tomography study

The aim was to examine the effects of recumbency and anaesthesia on distribution of ventilation in beagle dogs using Electrical Impedance Tomography (EIT). Nine healthy beagle dogs, aging 3.7±1.7 (mean±SD) years and weighing 16.3±1.6 kg, received a series of treatments in a fixed order on a single occasion. Conscious dogs were positioned in right lateral recumbency (RLR) and equipped with 32 EIT electrodes around the thorax. Following five minutes of equilibration, two minutes of EIT recordings were made in each recumbency in the following order: RLR, dorsal (DR), left (LLR) and sternal (SR). The dogs were then positioned in RLR, premedicated (medetomidine 0.01, midazolam 0.1, butorphanol 0.1 mg kg^-1 iv) and pre-oxygenated. Fifteen minutes later anaesthesia was induced with 1 mg kg^-1 propofol iv and maintained with propofol infusion (0.1–0.2 mg kg^-1 minute^-1 iv). After induction, the animals were intubated and allowed to breathe spontaneously (FIO₂ = 1). Recordings of EIT were performed again in four recumbencies similarly to conscious state. Centre of ventilation (COV) and global inhomogeneity (GI) index were calculated from the functional EIT images. Repeated-measures ANOVA and Bonferroni tests were used for statistical analysis (p < 0.05). None of the variables changed in the conscious state. During anaesthesia left-to-right COV increased from 46.8±2.8% in DR to 49.8±2.9% in SR indicating a right shift, and ventral-to-dorsal COV increased from 49.8±1.7% in DR to 51.8±1.1% in LLR indicating a dorsal shift in distribution of ventilation. Recumbency affected distribution of ventilation in anaesthetized but not in conscious dogs. This can be related to loss of respiratory muscle tone (e.g. diaphragm) and changes in thoracic shape. Changing position of thoraco-abdominal organs under the EIT belt should be considered as alternative explanation of these findings.

Responses to Bacteria, Virus, and Malaria Distinguish the Etiology of Pediatric Clinical Pneumonia

RATIONALE

Plasma-detectable biomarkers that rapidly and accurately diagnose bacterial infections in children with suspected pneumonia could reduce the morbidity of respiratory disease and decrease the unnecessary use of antibiotic therapy.

OBJECTIVES

Using 56 markers measured in a multiplexed immunoassay, we sought to identify proteins and protein combinations that could discriminate bacterial from viral or malarial diagnoses.

METHODS

We selected 80 patients with clinically diagnosed pneumonia (as defined by the World Health Organization) who also met criteria for bacterial, viral, or malarial infection based on clinical, radiographic, and laboratory results. Ten healthy community control subjects were enrolled to assess marker reliability. Patients were subdivided into two sets: one for identifying potential markers and another for validating them.

MEASUREMENTS AND MAIN RESULTS

Three proteins (haptoglobin, tumor necrosis factor receptor 2 or IL-10, and tissue inhibitor of metalloproteinases 1) were identified that, when combined through a classification tree signature, accurately classified patients into bacterial, malarial, and viral etiologies and misclassified only one patient with bacterial pneumonia from the validation set. The overall sensitivity and specificity of this signature for the bacterial diagnosis were 96 and 86%, respectively. Alternative combinations of markers with comparable accuracy were selected by support vector machine and regression models and included haptoglobin, IL-10, and creatine kinase-MB.

CONCLUSIONS

Combinations of plasma proteins accurately identified children with a respiratory syndrome who were likely to have bacterial infections and who would benefit from antibiotic therapy. When used in conjunction with malaria diagnostic tests, they may improve diagnostic specificity and simplify treatment decisions for clinicians.

Effect of Picture Archiving and Communication System Image Manipulation on the Agreement of Chest Radiograph Interpretation in the Neonatal Intensive Care Unit

OBJECTIVE

Variability in image interpretation has been attributed to differences in the interpreters' knowledge base, experience level, and access to the clinical scenario. Picture archiving and communication system (PACS) has allowed the user to manipulate the images while developing their impression of the radiograph. The aim of this study was to determine the agreement of chest radiograph (CXR) impressions among radiologists and neonatologists and help determine the effect of image manipulation with PACS on report impression.

MATERIALS AND METHODS

Prospective cohort study included 60 patients from the Neonatal Intensive Care Unit undergoing CXRs. Three radiologists and three neonatologists reviewed two consecutive frontal CXRs of each patient. Each physician was allowed manipulation of images as needed to provide a decision of "improved," "unchanged," or "disease progression" lung disease for each patient. Each physician repeated the process once more; this time, they were not allowed to individually manipulate the images, but an independent radiologist presets the image brightness and contrast to best optimize the CXR appearance. Percent agreement and opposing reporting views were calculated between all six physicians for each of the two methods (allowing and not allowing image manipulation).

RESULTS

One hundred percent agreement in image impression between all six observers was only seen in 5% of cases when allowing image manipulation; 100% agreement was seen in 13% of the cases when there was no manipulation of the images.

CONCLUSION

Agreement in CXR interpretation is poor; the ability to manipulate the images on PACS results in a decrease in agreement in the interpretation of these studies. New methods to standardize image appearance and allow improved comparison with previous studies should be sought to improve clinician agreement in interpretation consistency and advance patient care.

Novel Method to Improve Radiologist Agreement in Interpretation of Serial Chest Radiographs in the ICU

Objectives:

To determine whether a novel method and device, called a variable attenuation plate (VAP), which equalizes chest radiographic appearance and allows for synchronization of manual image windowing with comparison studies, would improve consistency in interpretation.

Materials and Methods:

Research ethics board approved the prospective cohort pilot study, which included 50 patients in the intensive care unit (ICU) undergoing two serial chest radiographs with a VAP placed on each one of them. The VAP allowed for equalization of density and contrast between the patients’ serial chest radiographs. Three radiologists interpreted all the studies with and without the use of VAP. Kappa and percent agreement was used to calculate agreement between radiologists’ interpretations with and without the plate.

Results:

Radiologist agreement was substantially higher with the VAP method, as compared to that with the non-VAP method. Kappa values between Radiologists A and B, A and C, and B and C were 46%, 55%, and 51%, respectively, which improved to 73%, 81%, and 66%, respectively, with the use of VAP. Discrepant report impressions (i.e., one radiologist's impression of unchanged versus one or both of the other radiologists stating improved or worsened in their impression) ranged from 24 to 28.6% without the use of VAP and from 10 to 16% with the use of VAP (χ² = 7.454, P < 0.01). Opposing views (i.e., one radiologist's impression of improved and one of the others stating disease progression or vice versa) were reported in 7 (12%) cases in the non-VAP group and 4 (7%) cases in the VAP group (χ² = 0.85, P = 0.54).

Conclusion:

Numerous factors play a role in image acquisition and image quality, which can contribute to poor consistency and reliability of portable chest radiographic interpretations. Radiologists’ agreement of image interpretation can be improved by use of a novel method consisting of a VAP and associated software and has the potential to improve patient care.

Inter-rater agreement in the evaluation of abdominal radiographs for necrotizing enterocolitis

PURPOSE

Abdominal radiographs are frequently employed in the surveillance of patients with necrotizing enterocolitis (NEC), with typical findings well described. Clinicians interpret and act upon these films at different intervals, however, and inter-rater agreement has not been evaluated to date.

METHODS

Thirty abdominal radiographs of premature infants were distributed to attending radiologists (4), pediatric surgeons (4), and trainees (4), who evaluated for findings of NEC from a list of eight potential choices (1=normal, 8=perforation). Fleiss's Kappa (FK) was used to evaluate concordance between multiple raters with 0-0.2=slight association and 0.8-1=almost perfect agreement.

RESULTS

Practicing surgeons had an FK of 0.77 overall (95% CI: 0.67-0.87), but demonstrated poor agreement when evaluating decubitus films (FK: 0.39, 95% CI:0.12-0.65). Radiologists had excellent inter-rater agreement (FK: 0.81, 95% CI: 0.74-0.88), but had only modest agreement with surgeons (FK: 0.59, 95% CI: 0.56-0.63) and poor agreement for decubitus films (FK: 0.15, 95% CI: 0.47-0.26). Surgical and radiology trainees had fair agreement with their respective attendings (0.60, 95% CI: 0.55-0.65 and 0.64, 95% CI: 0.60-0.69, respectively).

CONCLUSIONS

While inter-rater agreement was good-excellent among attending staff, it was only moderate between radiologists and surgeons and between trainees and their attendings. This highlights the importance of inter-disciplinary and hierarchical communication to optimize clinical decision-making. Decubitus films may be of limited value in evaluating patients with NEC.

Vitamin C for preventing and treating pneumonia

BACKGROUND

Pneumonia is one of the most common serious infections, causing two million deaths annually among young children in low-income countries. In high-income countries pneumonia is most significantly a problem of the elderly.

OBJECTIVES

To assess the prophylactic and therapeutic effects of vitamin C on pneumonia.

SEARCH METHODS

We searched CENTRAL 2013, Issue 3, MEDLINE (1950 to March week 4, 2013), EMBASE (1974 to April 2013) and Web of Science (1955 to April 2013).

SELECTION CRITERIA

To assess the therapeutic effects of vitamin C, we selected placebo-controlled trials. To assess prophylactic effects, we selected controlled trials with or without a placebo.

DATA COLLECTION AND ANALYSIS

Two review authors independently read the trial reports and extracted data.

MAIN RESULTS

We identified three prophylactic trials which recorded 37 cases of community-acquired pneumonia in 2335 people. Only one was satisfactorily randomised, double-blind and placebo-controlled. Two trials examined military recruits and the third studied boys from "lower wage-earning classes" attending a boarding school in the UK during World War II. Each of these three trials found a statistically significant (80% or greater) reduction in pneumonia incidence in the vitamin C group. We identified two therapeutic trials involving 197 community-acquired pneumonia patients. Only one was satisfactorily randomised, double-blind and placebo-controlled. That trial studied elderly patients in the UK and found lower mortality and reduced severity in the vitamin C group; however, the benefit was restricted to the most ill patients. The other therapeutic trial studied adults with a wide age range in the former Soviet Union and found a dose-dependent reduction in the duration of pneumonia with two vitamin C doses. We identified one prophylactic trial recording 13 cases of hospital-acquired pneumonia in 37 severely burned patients; one-day administration of vitamin C had no effect on pneumonia incidence. The identified studies are clinically heterogeneous which limits their comparability. The included studies did not find adverse effects of vitamin C.

AUTHORS' CONCLUSIONS

The prophylactic use of vitamin C to prevent pneumonia should be further investigated in populations who have a high incidence of pneumonia, especially if dietary vitamin C intake is low. Similarly, the therapeutic effects of vitamin C should be studied, especially in patients with low plasma vitamin C levels. The current evidence is too weak to advocate prophylactic use of vitamin C to prevent pneumonia in the general population. Nevertheless, therapeutic vitamin C supplementation may be reasonable for pneumonia patients who have low vitamin C plasma levels because its cost and risks are low.

Impact of clinical history on chest radiograph interpretation

BACKGROUND

The inclusion of clinical information may have unrecognized influence in the interpretation of diagnostic testing.

OBJECTIVE

The objective of the study was to determine the impact of clinical history on chest radiograph interpretation in the diagnosis of pneumonia.

DESIGN

Prospective case-based study.

METHODS

Radiologists interpreted 110 radiographs of children evaluated for suspicion of pneumonia. Clinical information was withheld during the first interpretation. After 6 months the radiographs were reviewed with clinical information. Radiologists reported on pneumonia indicators described by the World Health Organization (ie, any infiltrate, alveolar infiltrate, interstitial infiltrate, air bronchograms, hilar adenopathy, pleural effusion).

SETTING

Children's Hospital of Philadelphia and Boston Children's Hospital.

PARTICIPANTS

Six board-certified radiologists.

OUTCOME MEASURES

Inter- and inter-rater reliability were assessed using the kappa statistic.

RESULTS

The addition of clinical history did not have a substantial impact on the inter-rater reliability in the identification of any infiltrate, alveolar infiltrate, interstitial infiltrate, pleural effusion, or hilar adenopathy. Inter-rater reliability in the identification of air bronchograms improved from fair (k = 0.32) to moderate (k = 0.53). Intra-rater reliability for the identification of alveolar infiltrate remained substantial to almost perfect for all 6 raters with and without clinical information. One rater had a decrease in inter-rater reliability from almost perfect (k = 1.0) to fair (k = 0.21) in the identification of interstitial infiltrate with the addition of clinical history.

CONCLUSIONS

Alveolar infiltrate and pleural effusion are findings with high intra- and inter-rater reliability in the diagnosis of bacterial pneumonia. The addition of clinical information did not have a substantial impact on the reliability of these findings.

Variability in the interpretation of chest radiographs for the diagnosis of pneumonia in children

BACKGROUND

Although chest radiography is commonly used to establish the diagnosis of pneumonia in children, the reliability of radiographic findings among radiologists is not well described.

OBJECTIVE

We sought to evaluate the inter-rater and intra-rater reliability of radiographic features commonly described by radiologists in childhood pneumonia.

METHODS

Prospective case-based study. One hundred and ten radiographs of children evaluated in a pediatric emergency department for suspicion of pneumonia were interpreted by six radiologists at two academic children's hospitals. Radiologists were blinded to the clinical history. Reliability of standardized radiographic features was evaluated using the kappa statistic.

RESULTS

The radiographic finding of an alveolar infiltrate demonstrated substantial reliability among radiologists (κ = 0.69). The presence of 'any infiltrate' and pleural effusion demonstrated moderate reliability (κ = 0.47 and k=0.45, respectively). Other radiographic features were less reliable: air bronchograms (κ = 0.32), hilar adenopathy (κ = 0.21), and interstitial infiltrate (κ = 0.14). Similarly, the finding of alveolar infiltrate demonstrated substantial intra-rater reliability upon review of ten duplicate radiographs, whereas interstitial infiltrate was less reliable.

CONCLUSION

The radiographic finding of an alveolar infiltrate is very reliable among pediatric radiologists, whereas the finding of an interstitial infiltrate is less reliable.

Comparing the efficacy of nebulizer recombinant human DNase and hypertonic saline as monotherapy and combined treatment in the treatment of persistent atelectasis in mechanically ventilated newborns

BACKGROUND

The purpose of the present study was to compare the cost-effectiveness and efficacy of nebulizer recombinant human DNase (rhDNase) and hypertonic saline (HS) as monotherapy and combined treatment in neonatal atelectasis.

METHODS

Eighty-seven newborns with persistent atelectasis who did not respond to traditional treatment were studied retrospectively. Group 1 did not receive nebulizer drugs; Group 2 received 7%HS; Group 3 received rhDNase; and Group 4 received both 7%HS and rhDNase. Subjects' chest X-ray scores, partial pressure of CO(2), respiratory rate, fraction of inspired oxygen (FiO(2)) peak inspiratory pressure, atelectasis healing rate, median duration of nebulizer treatment and costs were compared.

RESULTS

Percentages of improvement in atelectasis on Day 3 of treatment in Group 1, Group 2, Group 3 and Group 4 were 27, 70, 81 and 95%, respectively, while median duration of treatment was 8.1, 3.3, 2.9 and 2.4 days, respectively. Comparison of chest X-ray scores, partial pressure of CO(2), respiratory rate, FiO(2) and peak inspiratory pressure values before and 48 h after treatment did not yield a significant difference for the control group (P > 0.05), while a marked improvement was observed in other groups for all parameters (P < 0.05). The most distinct improvement was in Group 4, followed by Group 3.

CONCLUSIONS

Although both the combined treatment with HS and rhDNase and their monotherapies are effective in the treatment of persistent atelectasis in newborns receiving mechanical ventilation, their combined use produces higher efficacy. The efficacy of rhDNase is superior to monotherapy with HS. Use of these two treatments concomitantly reduces the cost. To the best of our knowledge, the present study is the first to use HS alone or in combination with rhDNase in newborn patients.

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.

Intra and interobserver reliability of the interpretation of high-resolution computed tomography on the lungs of premature infants

CONTEXT AND OBJECTIVE

High-resolution computed tomography (HRCT) of the lungs is more sensitive than radiographs for evaluating pulmonary disease, but little has been described about HRCT interpretation during the neonatal period or shortly afterwards. The aim here was to evaluate the reliability of the interpretation of HRCT among very low birth weight premature infants (VLBWPI; < 1500 g).

DESIGN AND SETTING

Cross-sectional study on intra and interobserver reliability of HRCT on VLBWPI.

METHODS

86 VLBWPI underwent HRCT. Two pediatric radiologists analyzed the HRCT images. The reliability was measured by the proportion of agreement, kappa coefficient (KC) and positive and negative agreement indices.

RESULTS

For radiologist A, the intraobserver reliability KC was 0.79 (confidence interval, CI: 0.54-1.00) for normal/abnormal examinations; for each abnormality on CT, KC ranged from 0.05 to 1.00. For radiologist B, the intraobserver reliability KC was 0.79 (CI: 0.54-1.00) for normal/abnormal examinations; for each abnormality on CT, KC ranged from 0.37 to 0.83. The interobserver agreement was 88% for normal/abnormal examinations and KC was 0.71 (CI: 0.5- 0.93); for most abnormal findings, KC ranged from 0.51-0.67.

CONCLUSION

For normal/abnormal examinations, the intra and interobserver agreements were substantial. For most of the imaging findings, the intraobserver agreement ranged from moderate to substantial. Our data demonstrate that in clinical practice, there is no reason for more than one tomographic image evaluator, provided that this person is well trained in VLBWPI HRCT interpretation. Analysis by different observers should be reserved for research and for difficult cases in clinical contexts.

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.

Vitamin C for preventing and treating pneumonia

BACKGROUND

Pneumonia is one of the most common serious infections, causing two million deaths annually among young children in developing countries. In developed countries pneumonia is most significantly a problem of the elderly.

OBJECTIVES

To assess the prophylactic and therapeutic effects of vitamin C on pneumonia.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 1), OLD MEDLINE (1950 TO 1965), MEDLINE (1966 to February Week 2, 2006), EMBASE (1974 to March 2006), Web of Science (1945 to February 2006) and reference lists of reviews and articles.

SELECTION CRITERIA

To assess the therapeutic effects of vitamin C, we selected placebo-controlled trials. To assess prophylactic effects, we selected controlled trials with or without a placebo.

DATA COLLECTION AND ANALYSIS

Two review authors independently read the trial reports and extracted data.

MAIN RESULTS

We identified three prophylactic trials which recorded 37 cases of pneumonia in 2,335 people. Only one was satisfactorily randomised, double-blind and placebo-controlled. Two trials examined military recruits and the third studied boys from "lower wage-earning classes" attending a boarding school in the UK during World War II. Each of these trials found a statistically significant (80% or greater) reduction in pneumonia incidence in the vitamin C group. We identified two therapeutic trials involving 197 pneumonia patients. Only one was satisfactorily randomised, double-blind and placebo-controlled. One studied elderly patients in the UK which found lower mortality and reduced respiratory symptom scores in the vitamin C group; however, the benefit was restricted to the most ill patients. The other studied adults (with a wide age range) in the former Soviet Union and found a dose-dependent reduction in the time to recovery with two vitamin C doses.

AUTHORS' CONCLUSIONS

The prophylactic use of vitamin C to prevent pneumonia should be further investigated in populations who have high incidence of pneumonia, especially if dietary vitamin C intake is low. Similarly, the therapeutic effects of vitamin C should be studied especially in patients with low plasma vitamin C levels. The current evidence is too weak to advocate widespread prophylactic use of vitamin C to prevent pneumonia in the general population. However, therapeutic vitamin C supplementation may be reasonable for pneumonia patients who have low vitamin C plasma levels because its cost and risks are low.

Recombinant human deoxyribonuclease shortens ventilation time in young, mechanically ventilated children

Recombinant human deoxyribonuclease I (dornase alfa) is currently used as an inhaled mucoactive agent in the treatment of cystic fibrosis. In a randomized, placebo-controlled, double-blind clinical study in 100 infants, we investigated whether the therapeutic use of dornase alfa can be extended to ventilated, fluid-restricted children to reduce reintubation rate, ventilation duration, pediatric intensive care unit (PICU) stay, and ventilation complications. While reintubation rates were similar for dornase alfa 7% vs. placebo 9% (odds ratio, 0.77; confidence interval, 0.11-4.9), the incidence of atelectasis (6 vs. 17, respectively; P-value 0.051), median ventilation time (2.2 vs. 3.4 days, respectively; P-value 0.043), median length of PICU stay (7 vs. 8 days, respectively; P-value 0.051), and mean costs (4,830 vs. 6,320, respectively) were lower in the dornase alfa group. No adverse effects were observed, even in critically ill patients. We found that dornase alfa was beneficial and safe. Our findings also indicate that dornase alfa is possibly of value from the first day of mechanical ventilation onward, particularly when longer ventilation (>3 days) is expected in fluid-restricted children after cardiac surgery.

Does variation in interpretation of ultrasonograms account for the variation in incidence of germinal matrix/intraventricular haemorrhage between newborn intensive care units in New Zealand?

BACKGROUND

The incidence of germinal matrix/intraventricular haemorrhage (GM/IVH) reported to the Australian and New Zealand Neonatal Network (ANZNN) varies between neonatal intensive care units (NICUs).

HYPOTHESIS

Differences in the capture, storage, and interpretation of the cerebral ultrasound scans may account for some of this variation.

METHODS

A total of 255 infants with birth weight <1500 g and gestation <32 weeks born between 1997 and 2002 were randomly selected from the ANZNN database, 44 from each of the six NICUs in New Zealand. Twenty two infants from each NICU had cerebral ultrasound scans previously reported to ANZNN as normal; another 22 had scans reported as abnormal. The original scans were copied using digital photography and anonymised and independently read by a panel of three experts using a standardised method of reviewing and reporting.

RESULTS

There was considerable variation between NICUs in methods of image capture and quality and completeness of the scans. However, there was little variation in the reporting of scans between the reviewers and the reports to ANZNN (weighted kappa 0.75-0.91). Grade 1 GM/IVH was generally over-reported and grade 4 under-reported to the ANZNN.

CONCLUSION

For all NICUs, a high level of agreement was found between the reviewers' reports and the reports to the ANZNN. Thus the variation between NICUs in the incidence of GM/IVH reported to the ANZNN is unlikely to be due to differences in capture, storage, and interpretation of the cerebral ultrasound scans. Further investigation is warranted into the reasons for the variation in incidence of GM/IVH between NICUs.

Digital imaging does not improve localization of percutaneously inserted central lines in neonates

OBJECTIVE

To determine whether the use of digital imaging improves the localization of percutaneously inserted central (PIC) line tips compared to standard radiographs, with contrast being used in both cases.

METHODS

Digital radiographs taken for localization of PIC lines between October 2002 and September 2003 were identified from the neonatal database. Two reporters independently reviewed the radiographs and stated (i) whether the tip could confidently be seen and (ii) the position. The observers were encouraged to use all the image modification modalities available. The formal radiology report was taken as the third 'reporter'.

RESULTS

Overall 117 digital radiographs from 98 infants were reviewed. Reporter 1 identified the tip in 83 (71%); reporter 2 in 84 (72%); and the radiologist in 95 (81%), although all agreed that the tip could be identified in only 55 (47%) radiographs. In radiographs where the reporters agreed that the tip could be identified, they agreed on the position in 37 (67%) cases. In 61 (52%) radiographs the reporters did not agree that the tip could be seen, but they agreed on its position in 36 (59%) cases. The kappa coefficient for agreement on line position was 0.63. The level of agreement between reporters in this study using digital imaging was not significantly different from our previous findings using standard radiography with contrast (74/117, 63% vs 57/96, 59%).

CONCLUSION

The use of digital imaging, with its ability to manipulate images in order to identify PIC line tips, is not significantly better than using standard radiography with contrast.

Tracheobronchoscopic assessment of exercise-induced pulmonary hemorrhage in horses

OBJECTIVE

To determine the interobserver variability of assessment of exercise-induced pulmonary hemorrhage (EIPH) during tracheobronchoscopic examination in horses.

ANIMALS

747 Thoroughbred racehorses. Procedures-850 tracheobronchoscopic examinations were performed within 2 hours of racing for the horses. Examinations were recorded on videotape, and EIPH and its severity were assessed independently by 3 veterinarians. Concordance was determined by calculation of the Cohen weighted kappa statistic and tabulation of scores assigned by each observer.

RESULTS

Weighted kappa statistics ranged from 0.75 to 0.80. In 99.4% of observations, all observers agreed or 2 of 3 agreed and the third differed by < or = 1 grade.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that interobserver reliability of tracheobronchoscopic assessment of EIPH in Thoroughbred racehorses is high when the examination is conducted by experienced veterinarians. Concordance among investigators is sufficient to justify use of this grading system for further studies and clinical descriptions of EIPH.

Middle lobe syndrome in children with asthma: review of 56 cases

OBJECTIVE

Middle lobe syndrome (MLS) is one of the complications of asthma. Its signs and symptoms are often nonspecific, causing delay in appropriate treatment. We aimed to review our pediatric asthmatic patients and provide differential characteristics between MLS and asthma worsening in order to target early diagnosis.

METHOD

File records of all asthmatics (n=3528) seen in our clinic during the last 2 years were retrospectively reviewed to identify the patients with MLS, and a case-control study was undertaken. Files of 56 asthmatic children diagnosed as MLS, with a total of 63 episodes, and 63 matched controls with asthma worsening were analyzed and compared.

RESULTS

The incidence of MLS was 1.62% and half were below or at the age of 6. All cases with MLS were documented radiologically, and only 5 of the 63 episodes had physical findings suspicious for MLS. The most affected segments were right middle lobe (50%) and left lingula (26.2%). Although in all cases symptoms cleared, in 23 (36.5%) cases, atelectasis persisted radiologically. Compared to controls, patients with MLS included less atopics (34.9% vs. 59.4%, p<0.05) and fewer boys (52.4% vs. 71.4%, p<0.05), and they reported less frequent dyspnea (57.1% vs. 85.9%), more frequent sputum production (49.2% vs. 7.8%), and longer duration of complaints (22.0+/-6.23 vs. 2.4+/-0.31 days) (p<0.001, for each). Furthermore, the resolution of symptoms took significantly longer (45.2+/-9.3 vs. 3.3+/-0.4 days, p<0.001).

CONCLUSION

We conclude that complicating MLS in childhood asthma is more frequent in younger ages, girls, and nonatopics. In most cases, physical findings are not informative, and chest radiographs diagnose most but not all cases. The most suggestive symptoms are unresolving/persisting symptoms during admission and/or following treatment.

Does radio-opaque contrast improve radiographic localisation of percutaneous central venous lines?

BACKGROUND

Percutaneous central venous lines (long lines) are commonly used in neonatal practice. The position of these lines is important, because incorrect placement may be associated with complications.

AIMS

To determine whether the addition of radio-opaque contrast material improves the localisation of long line tips over plain radiography.

METHODS

Radiographs taken to identify long line position were identified in two periods; 106 radiographs without contrast taken between October 1999 and August 2000, and 96 radiographs with contrast between September 2001 and July 2002. Two observers independently reviewed each radiograph to identify the position of the line tip. The formal radiology report was recorded as a third observer.

RESULTS

The use of contrast increased the proportion of radiographs in which all observers reported they could see the long line tip (53 (55%) v 41 (39%)). It also increased the proportion where they agreed on anatomical position (57 (59%) v 39 (37%)) and there was a higher kappa coefficient for agreement (0.56 v 0.33).

CONCLUSIONS

The use of contrast while taking radiographs for the localisation of long line position improves the likelihood that an observer can see a long line tip and reduces inter-observer variability. Even using contrast, precise localisation of a long line tip can be difficult.

Interobserver variation in interpreting chest radiographs for the diagnosis of acute respiratory distress syndrome

To measure the reliability of chest radiographic diagnosis of acute respiratory distress syndrome (ARDS) we conducted an observer agreement study in which two of eight intensivists and a radiologist, blinded to one another's interpretation, reviewed 778 radiographs from 99 critically ill patients. One intensivist and a radiologist participated in pilot training. Raters made a global rating of the presence of ARDS on the basis of diffuse bilateral infiltrates. We assessed interobserver agreement in a pairwise fashion. For rater pairings in which one rater had not participated in the consensus process we found moderate levels of raw (0.68 to 0.80), chance-corrected (kappa 0.38 to 0.55), and chance-independent (Phi 0. 53 to 0.75) agreement. The pair of raters who participated in consensus training achieved excellent to almost perfect raw (0.88 to 0.94), chance-corrected (kappa 0.72 to 0.88), and chance-independent (Phi 0.74 to 0.89) agreement. We conclude that intensivists without formal consensus training can achieve moderate levels of agreement. Consensus training is necessary to achieve the substantial or almost perfect levels of agreement optimal for the conduct of clinical trials.