Aleksandar Sovtic

Home mechanical ventilation in children is feasible in developing countries

Background:  The results of many national surveys on pediatric home mechanical ventilation (HMV) in developed countries have been presented elsewhere, but data from developing countries with low national incomes are scarce.

Static Hyperinflation Is Associated With Decreased Peak Exercise Performance in Children With Cystic Fibrosis

BACKGROUND: We evaluated the exercise capacity of children with cystic fibrosis to determine whether ventilatory limitation associated with static hyperinflation is related with decreased exercise capacity, thus predisposing these children to arterial hypoxemia during progressive exercise. METHODS: Thirty-seven children, ages 8–17 years, underwent spirometry, body plethysmography, and cardiopulmonary exercise testing after arterial catheter placement. According to the ratio of residual volume to total lung capacity (RV/TLC), the subjects were categorized as either with (RV/TLC > 30%) or without static hyperinflation (RV/TLC < 30%). RESULTS: Children with static hyperinflation showed lower values of maximum load per kilogram (% predicted) (P = .01), which was aggravated by ventilatory limitation (FEV1 < 80% of predicted, peak oxygen consumption [% predicted] < 85%, and breathing reserve index > 0.7). Subjects with ventilatory limitation had significantly lower oxygen saturation (P = .04) and hypoxemia (P = .03) than did subjects without ventilatory limitation. CONCLUSIONS: In children with cystic fibrosis, static hyperinflation and ventilatory limitation are associated with decrease in exercise performance, oxygen saturation, and PaO2 during maximum cardiopulmonary exercise testing. All children with cystic fibrosis who exhibit static hyperinflation and ventilatory limitation may require SaO2 monitoring during progressive exercise.

Clinical characteristics of respiratory syncytial virus infection in neonates and young infants.

INTRODUCTION/AIM Infection with respiratory syncytial virus (RSV) occurs during the first year of life in 50% of children and 20%-40% of them have signs of lower respiratory tract infection (bronchiolitis or pneumonia). There is an increased risk for complicated course and death from RSV infection in premature infants, especially those with bronchopulmonary dysplasia (BPD) or congenital heart disease. The aim of our study was to analyze clinical characteristics of laboratory confirmed RSV infection in order to evaluate the need for preventive measures in neonates and young infants. METHODS The prospective study included children under age of 12 months admitted to our hospital in the period November 2008-March 2009 who were positive for RSV by enzyme immunoassay membrane test. The course of disease was assessed by clinical score and radiographic findings. RESULTS Infection with RSV was confirmed in 91 patients: 21 (23.0%) were under the age of 30 days, 37 (40.7%) were between 31-60 days, and 33 patients (36.3%) were older than 60 days (p > 0.05). The highest hospitalization rate was in January--33 patients (36.3%; p < 0.01). Disease severity score in these age groups (AG) were: 8.4 +/- 0.4 (AG 0-30 days); 9.0 +/- 0.3 (AG 31-60 days) and 8.3 +/- 0.3 (AG > 60 days), without statistically significant difference among the groups (p > 0.05). Clinical scores in patients with and without risk factors were 10.5 +/- 0.5 and 8.3 +/- 0.2, respectively (p < 0.01). Pathological radiographic findings were observed in 72 (79.1%) and complications (apnea, significant atelectasis, encephalopathy) occured in 15 (16.5%) patients. The average length of hospital stay in complicated and uncomplicated course of the disease was 9 days and 6 days, respectively (p < 0.01). Therapy in 85 (93.4%) patients included bronchodilators, while systemic glucocorticoids and oxygen therapy were used in 51 (56.0%) and 44 (48.4%) patients, respectively. Death occured in 2 (2.2%) patients, both from a high risk group (the patient with BPD and the other one with congenital heart disease and Down syndrome). CONCLUSION Infection with RSV in our settings showed marked seasonal characteristics with highest hospitalization rate in January. Although the course and outcome of the disease were favorable in the majority of our patients, the need for hospitalization and administration of therapy with possible side effects warrants that general measures for prevention of respiratory infections are followed especially in the first year of life. Severe disease and death are more probable in neonates and infants with risk factors. In these children passive immunisation with specific monoclonal antibody (e.g. palivizumab) during RSV season should be considered.

Surgical treatment of severe laryngomalacia: Six month follow up

Laryngomalacia (LM) is the most common congenital anomaly of larynx that causes stridor in children. We evaluated the efficacy of epiglottic suture and laser epiglottopexy for treatment of infants with severe LM.

Successful treatment of laryngomalacia and bilateral vocal cord paralysis with continuous positive airway pressure

INTRODUCTION Laryngomalacia is the most frequent congenital anomaly of airways, and it may cause obstructive sleep apneas. The associated vocal cord paralysis may aggravate the symptoms of upper airway obstruction. CASE REPORT In a 14 month old boy severe laryngomalacia and bilateral vocal cord paralysis were diagnosed by flexible bronchoscopy. A sleep study showed a severe obstructive sleep apnoea (OSA). The patient was ventilated at home via the face mask with non invasive mechanical ventilation (CPAP) for a year. The level of pressure had to be set at 7 cm H2O to correct desaturation with an improvement in mean SpO2. On the follow up bronchoscopic examination laryngomalatia was improved, vocal cord paralysis persisted and sleep study revealed significant improvement. DISCUSSION In the patient with severe laryngomalatia and bilateral vocal cord paralysis with OSA conservative treatment with CPAP was used instead of a surgical intervention. Non invasive ventilation was used every night, for at least 6 hours, without adverse events. Invasive measurement of transdiaphragmatic pressure is the best way of titrating of CPAP level. This case report suggests the efficacy of noninvasive titrating of CPAP level by the hemoglobin oxygen saturation trend measurement. CONCLUSION In case of severe laryngomalatia and associated vocal cord paralysis, followed by OSA non invasive ventilation by nasal CPAP represents an effective and safe alternative to surgery.

Virulence traits associated with Burkholderia cenocepacia ST856 epidemic strain isolated from cystic fibrosis patients

BackgroundBurkholderia cenocepacia is considered one of the most problematic cystic fibrosis (CF) pathogens. Colonization prevalence in the Serbian CF population is high and virtually exclusively limited to a single highly transmissible clone of B. cenocepacia ST856 which is positive for both the B. cepacia epidemic strain marker (BCESM) and cable pilin, and is closely related to the epidemic strain CZ1 (ST32).MethodsBiofilm formation for 182 isolates, and adhesion to components of the host extracellular matrix, proteolytic activity, mucoidy and motility of selected ST856 representatives, as well as B. cenocepacia ST858 and ST859, and B. stabilis ST857, novel STs isolated from Serbian CF patients, were investigated in this study. The presence of the cepI, cepR, fliG, llpE, wbiI, and bcscV genes was analyzed.ResultsBiofilm-formation ability of analyzed strains was poor under standard laboratory conditions, but changed in stress conditions (cold stress) and conditions that mimic CF milieu (increased CO2). All strains expressed ability to bind to collagen and fibronectin albeit with different intensity. Representatives of ST856 exhibited gelatinase activity. ST858, ST859 and 9/11 of ST856 genotypes were positive for swimming and twitching motility whereas ST857 was non-motile. Mucoidy was demonstrated in all ST856 genotypes, ST857 was semi-mucoid, and ST858 and ST859 were non-mucoid. Molecular analysis for major virulence factors revealed that ST856 and ST857 carried the six analyzed genes, while ST858 and ST859 were negative for the llpE gene.ConclusionVariations in virulence phenotypes in different genotypes of epidemic B. cenocepacia ST856 clone, in vitro, could be a consequence of diversification driven by pathoadaptation. Diversity of epidemic clone genotypes virulence, could be challenging for accurate diagnosis and treatment, as well as for infection control.

N-terminal pro-brain natriuretic peptide in the assessment of respiratory distress in term neonates

N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) is used as a biomarker to differentiate congestive heart failure from lung disease in adults and children. The clinical significance of its use in term neonates has not yet been extensively studied.

Newborn screening for cystic fibrosis in Serbia: A pilot study

We performed a pilot study of neonatal screening for cystic fibrosis (CF) in order to introduce it to the national screening program in Serbia.

Genomic profiling supports the diagnosis of primary ciliary dyskinesia and reveals novel candidate genes and genetic variants

Primary ciliary dyskinesia (PCD) is a rare inherited autosomal recessive or X-linked disorder that mainly affects lungs. Dysfunction of respiratory cilia causes symptoms such as chronic rhinosinusitis, coughing, rhinitis, conductive hearing loss and recurrent lung infections with bronchiectasis. It is now well known that pathogenic genetic changes lead to ciliary dysfunction. Here we report usage of clinical-exome based NGS approach in order to reveal underlying genetic causes in cohort of 21 patient with diagnosis of PCD. By detecting 18 (12 novel) potentially pathogenic genetic variants, we established the genetic cause of 11 (9 unrelated) patients. Genetic variants were detected in six PCD disease-causing genes, as well as in SPAG16 and SPAG17 genes, that were not detected in PCD patients so far, but were related to some symptoms of PCD. The most frequently mutated gene in our cohort was DNAH5 (27.77%). Identified variants were in homozygous, compound heterozygous and trans-heterozygous state. For detailed characterization of one novel homozygous genetic variant in DNAI1 gene (c. 947_948insG, p. Thr318TyrfsTer11), RT-qPCR and Western Blot analysis were performed. Molecular diagnostic approach applied in this study enables analysis of 29 PCD disease-causing and related genes. It resulted in mutation detection rate of 50% and enabled discovery of twelve novel mutations and pointed two possible novel PCD candidate genes.

Respiratory Muscle Strength and Exercise Performance in Cystic Fibrosis–A Cross Sectional Study

Introduction: Decreased respiratory muscle strength in patients with cystic fibrosis (CF) may cause progressive exercise intolerance during cardiopulmonary exercise testing (CPET), and may contribute to the development of chronic respiratory insufficiency. The aim of this study is to evaluate exercise tolerance during CPET of children and adults with clinically stable CF who exhibit different respiratory muscle strength. Methods: Sixty-nine clinically stable CF subjects aged 8–33 years underwent spirometry, body plethysmography, CPET, and respiratory muscle strength measurement. Respiratory muscle strength was measured using maximal inspiratory pressures (Pimax) and maximal expiratory pressures (Pemax). Participants were stratified into three groups according to Pimax values:below normal (≤80% predicted), normal (81–100% predicted), and above normal (>100% predicted). A similar stratification of participants was made according to Pemax values. The oxygen consumption on peak load (VO2peak) was expressed relative to BM (VO2peak/kg), relative to BM raised by the exponent of 0.67 (VO2peak/kg0.67) and as log-linear adjustment of VO2peak (VO2peak/kg−alo). Results: Participants with low Pemax values had a lower mean maximum load per kilogram/predicted (Wmax; p = 0.001) VO2peak/kg (p = 0.006), VO2peak/kg0.67 (p = 0.038) and VO2peak/kg−alo (p = 0.001). There were no significant differences in exercise tolerance parameters with regard to Pimax values. Stepwise multiple linear regressions confirmed that Pemax (B = 24.88, β = 0.48, p < 0.001) was the most powerful predictor of Wmax. There were no statistically significant differences in age, lung function parameters, exacerbation score, or respiratory muscle strength according to gender. Conclusions: In subjects with clinically stable CF, expiratory muscle strength is associated with a decrease in exercise performance during CPET and can predict exercise intolerance. Increase in expiratory muscle strength by patient specific rehabilitation protocols would result in improvement of exercise tolerance.