María E.Y. Furuya

Sweat conductivity and chloride titration for cystic fibrosis diagnosis in 3834 subjects

Sweat test is the standard for cystic fibrosis (CF) diagnosis. Conductivity is an alternative method not yet approved, in spite of its good correlation with chloride concentration. The aim was to assess the capacity of sweat conductivity to discriminate between CF and non-CF subjects. Automated measurements of conductivity and chloride concentration were carried out on the same sweat samples from subjects with clinical suspicion of CF. Sweat samples from 3,834 subjects, median age 1.8 years (range 1 month-54 years) were analysed, and those with chloride titration >60 mmol/l were considered as CF patients (n=294). Conductivity median values in CF and non-CF subjects were 111 mmol/l (82-148) and 36 mmol/l (12-89), respectively. The Spearman correlation between chloride titration and conductivity was r=0.60 (P<0.001). The receiver operating characteristics (ROC) curve showed very high agreement between two methods. The best conductivity cut-off value to diagnose CF was > or =90 mmol/l (sensitivity 99.7%, specificity 100%, positive and negative predictive values of 100% and 99.97%, respectively, and kappa=0.998). Likewise, the best conductivity cut-off value to exclude CF was <75 mmol/l. The sweat conductivity method showed good correlation with chloride titration, and accurately discriminated between subjects with and without CF. In accordance with this, CF diagnosis might be confirmed for conductivity values > or =90 mmol/l and excluded for <75 mmol/l. Values between 75 and 89 mmol/l should correspond to an equivocal range. However, more studies are needed to confirm the role of conductivity in definitive CF diagnosis.

Lipoid Pneumonia in Children:: Clinical and Imagenological Manifestations

BACKGROUND Oil-aspiration pneumonia is still a health problem in countries where infants are forced to receive vegetable or animal oil due to traditional habits. The aim of this paper is to present clinical and imagenological characteristics of lipoid pneumonia (LP) in children and a review of the literature. Distinguishing features of and differences between other series are presented. METHODS Series of cases. We retrospectively analyzed all records of children with lipoid pneumonia between 1991 and 1996. RESULTS We found 16 patients aged 1-19 months old with positive oil ingestion in 75% and history of recurrent or persistent pneumonia in 81.2%. In almost 70% of patients, there were underlying conditions known as risk factors of aspiration. Plain films and computed tomography (CT) showed that the right lung was always involved. Fat density was found in only two cases. Bronchoscopy with bronchial lavage was performed in 15 patients, with lipophages positive in each patient. CONCLUSIONS Lipoid pneumonia must be ruled out in the differential diagnosis in infants with persistent or recurrent pneumonia with or without fever, especially in patients with aspiration risk factors. Bronchoscopy with bronchial lavage and positive lipid-laden alveolar macrophages proved a useful method for diagnosis of this condition. More studies are needed to ascertain the clinical and imagenological evolution of this condition.

Main diagnosis and cause of death in a neonatal intensive care unit: do clinicians and pathologists agree?

Aim: To determine the agreement rates between clinical and autopsy diagnoses in a neonatal intensive care unit (NICU), distinguishing between the main diagnosis and cause of death. Methods: Clinical and autopsy records of 75 infants who died in two consecutive years in the NICU (autopsy rate 42.6%) of a pediatric hospital in Mexico City were reviewed. Results: Ninety‐two percent of main clinical diagnoses were confirmed by autopsy. Four conditions (congenital cardiopathy, prematurity, specific congenital syndromes and hyaline membrane disease) accounted for more than two‐thirds of diagnoses. However, for cause of death, the global agreement was only 50%. The most common conditions considered by clinicians (77%) and pathologists (56%) to be the causes of death were cardiogenic, septic or mixed shocks. Additionally, clinicians omitted 34 relevant conditions in 30 (40.0%) patients, and 21 of these conditions possibly played a role in the deaths of 17 (22.7%) patients. The most frequently omitted diagnosis was pneumonia, in 9 (26.5%) patients. Omissions were not related to gestational age, age at death, days as an inpatient, or gender.

Passive Smoking Induces Leukotriene Production in Children: Influence of Asthma

Background. Passive smoking is associated with poor asthma control in children, but the mechanism is unknown. Leukotrienes are involved in the asthma pathogenesis and their synthesis is increased in adult subjects who actively smoke. Objective. To evaluate whether passive smoking, as assessed by urinary cotinine levels, increases leukotriene production in children with or without asthma. Methods. This was a prospective, cross-sectional study in which children with stable intermittent asthma (without exacerbation) and healthy control children were studied through spirometry and urinary concentrations of cotinine and leukotriene E4 (LTE4). Both groups were balanced to include children with and without passive smoking. Results. Ninety children (49 with asthma and 41 controls, 54.4% females) aged 9 years (range, 5–13 years) were studied. Urinary LTE4 concentrations were progressively higher as cotinine levels increased (rS = 0.23, p = .03). LTE4 also correlated with body mass index (BMI) (rS = 0.30, p = .004), and multiple regression analysis revealed that BMI was even more influential than cotinine for determining LTE4 levels. LTE4 concentrations were unrelated with gender, age, or spirometry. In turn, cotinine inversely correlated with forced expiratory volume in one second (FEV1) (rS = −0.22, p = .04) and forced vital capacity (FVC) (rS = −0.25, p = .02), but when analyzed by groups, these relationships were statistically significant only in children with asthma. Conclusions. Exposure to environmental tobacco smoke, as assessed by urinary cotinine levels, was associated with an increased urinary concentration of LTE4, although BMI exerted more influence in determining its concentration. Urinary cotinine was associated with decreased lung function, mainly in children with asthma.

Oral hygiene and dental status as factors related to asthma in high school and college students.

Abstract Objective: Considering that oral microbiota might modulate immune responses, we explored if customary oral care procedures might influence immune-driven diseases such as asthma. Methods: This was a retrospective, cross-sectional analysis of responses to a self-completion medical questionnaire applied to subjects entering into college and high school programs during 2006–2011. Results: Responses from 329 780 students aged 14–24 years (97.6% of the original population) were analyzed. The prevalence of lifetime asthma was 4.01%. Subjects with asthma were slightly older, taller and heavier than subjects without asthma, and these differences were equally present in males and females. Subjects currently having two or more decayed teeth had asthma less frequently than those with one or none decayed tooth, with an odds ratio (OR) = 0.86 and 95% confidence interval (95% CI) 0.83–0.89. In contrast, asthma was reported more frequently among students having two or more missing or filled teeth [OR = 1.1 (95% CI 1.04–1.17) and OR = 1.05 (95% CI 1.01–1.09), respectively]. From 2008 onwards, subjects also responded questions about oral hygiene incorporated into the core questionnaire. In these subjects, the use of toothpaste as well as the frequency and duration of toothbrushing were unrelated to asthma; regular use of mouthwash was associated with asthma in women [OR = 1.16 (95% CI 1.07–1.25)], but not in men [OR = 1.04 (95% CI 0.96–1.13)]. Results of multiple logistic regressions were in line with these findings. Conclusions: Our results suggested that oral hygiene and dental status could be novel factors influencing asthma development, and thus further studies to confirm and clarify this association are warranted.

Reference values for airway resistance in newborns, infants and preschoolers from a Latin American population.

Background and objective:  Several studies have determined reference values for airway resistance measured by the interrupter technique (Rint) in paediatric populations, but only one has been done on Latin American children, and no studies have been performed on Mexican children. Moreover, these previous studies mostly included children aged 3 years and older; therefore, information regarding Rint reference values for newborns and infants is scarce.

Efficacy of human recombinant DNase in pediatric patients with cystic fibrosis.

BACKGROUND Most respiratory complications in cystic fibrosis (CF) arise from abnormally viscid mucus, and rhDNase has shown to be effective in enhancing mucous clearance. We explored the responses to rhDNase in a Mexican population of CF patients. METHODS Patients with CF received aerosolized rhDNase (2.5 mg daily) during 3 months, followed by daily aerosolized placebo during 3 months. RESULTS A total of 21 CF patients entered the study (11.1 +/- 0.5 years of age, mean +/- SEM, 10 girls): 15 patients (71%) had basal forced vital capacity (FVC) higher than the 70% predicted value, and the remainder of the patients had an FVC of between 30 and 70%. As a group, rhDNase progressively increased the forced expiratory flow at 1 sec (FEV1) as well as the FVC, reaching statistical significance (p <0.005) at the end of the third month of treatment. Sputum production and difficulty to expectorate or to breathe also improved during the rhDNase treatment period (p <0.05 to p <0.001). All these changes progressively decreased to basal values after 3 months with aerosolized placebo. Adverse reactions were almost null, with a sole patient reporting dysphonia. CONCLUSIONS Aerosolized rhDNase was effective in progressively improving respiratory function and symptoms in most CF patients.

Guidelines for diagnosing and treating pulmonary infiltrates in children with acute leukaemia: impact of timely decisions

Aim: Children with leukaemia are at increased risk of pulmonary complications, often with unspecific clinical data, delayed diagnosis and a high mortality rate. We evaluated the usefulness of diagnostic–therapeutic guidelines (DTG) in which specific times for decision making were incorporated.

Diagnoses unveiled by early bronchoscopy in children with leukemia and pulmonary infiltrates.

Pulmonary complications in children with leukemia often display nonspecific clinical and radiologic manifestations that lead to a delay in diagnosis. The role of fiberoptic bronchoscopy (FOB) and the proper time for its performance are controversial. The aim of our study was to evaluate the frequency and nature of specific diagnoses revealed by FOB. Children with leukemia submitted to FOB because of suspicion of pulmonary involvement (mainly pneumonia) were retrospectively analyzed. A total of 33 FOB procedures performed in 31 patients (20 males) with an average age of 9.4 years (range, 3.5 to 15 y) were evaluated. Microorganisms isolated from 21 (63.6%) bronchoalveolar lavage samples were mainly fungi including Candida in 13 cases (39.4%) and Aspergillus in 3 cases (9.1%). Isolation rate in 10 procedures performed within the first 3 days was 90%. Tracheobronchitis was present in >50% of patients, pulmonary hemorrhage was seen in 7 (21.0%) patients, and leukemic infiltration was demonstrated in 2 patients (6.1%), among other conditions visualized by FOB. Complications of FOB were minimal and transient. Our study suggests that FOB is a useful and safe procedure in patients with leukemia and pulmonary infiltrates. The earlier the FOB was performed, the higher the isolation rate of causative agents. In addition, this procedure allowed the identification of noninfectious airway comorbidities. Further studies in regard to this issue are warranted.

Endoscopy for the initial suspicion of vascular rings in tracheoesophageal compressions: Correlation with surgical findings

Vascular rings (VR) may produce extrinsic compression of trachea and/or esophagus. Diagnosis relies on nonspecific clinical data from resulting compression and image studies, mainly angiography, computed tomography, and cardiovascular MRI. Because of their low incidence, diagnosis is often missed. The role of bronchoscopy and esophagoscopy is controversial, but these procedures might establish for the first time the diagnostic suspicion of VR. This communication was aimed to determine to what extent endoscopic manifestations lead the clinician to suspect the presence of a VR and, moreover, to define their correlation with surgical findings.