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Since inflammation and oxidative stress are fundamental in the pathophysiology of neonatal meconium aspiration syndrome (MAS), various anti-inflammatory drugs have been used in experimental and clinical studies on MAS. This pilot study evaluated therapeutic potential of N-acetylcysteine in modulation of meconium-induced inflammation and oxidative lung injury. Oxygen-ventilated adult rabbits were intratracheally given 4 ml/kg of meconium (25 mg/ml) or saline (Sal, n = 6). Thirty minutes later, meconium-instilled animals were treated with intravenous N-acetylcysteine (10 mg/kg, Mec + NAC, n=6) or were non-treated (Mec, n = 6). All animals were oxygen-ventilated for additional 5 hours. Total and differential blood leukocyte counts were determined at baseline, and at 1, 3 and 5 h of the treatment. After sacrificing animals, left lung was saline-lavaged and total and differential cell counts in the bronchoalveolar lavage fluid were determined. Right lung was used for biochemical analyses and for estimation of wet-dry weight ratio. In lung tissue homogenate, thiobarbituric acid-reactive substances (TBARS), dityrosine, lysine-lipid peroxidation (LPO) products, and total antioxidant status (TAS) were detected. In isolated lung mitochondria, TBARS, dityrosine, lysine-LPO products, thiol group content, conjugated dienes, and activity of cytochrome c oxidase were estimated. To evaluate systemic effects of meconium instillation and NAC treatment, TBARS and TAS were determined also in plasma. To evaluate participation of eosinophils in the meconium-induced inflammation, eosinophil cationic protein (ECP) was detected in plasma and lung homogenate. Meconium instillation increased oxidation markers and ECP in the lung and decreased TAS (all P<0.05). NAC treatment reduced ECP and oxidation markers (all P<0.05, except of dityrosine in homogenate and conjugated dienes in mitochondria) and prevented a decrease in TAS (P<0.01) in lung homogenate compared to Mec group. In plasma, NAC decreased TBARS (P<0.001) and ECP, and increased TAS (both P<0.05) compared to Mec group. Concluding, N-acetylcysteine diminished meconium-induced inflammation and oxidative lung injury.

Combination of low-dose budesonide and low-dose aminophylline may improve lung function in reduced adverse effects compared with high-dose monotherapy. Adult rabbits intratracheally received 4 ml/kg of saline or meconium (25 mg/ml). Meconium-injured rabbits were treated at 0.5 and 2.5 h after meconium instillation by intravenous aminophylline (1.0 mg/kg), by intratracheal budesonide (0.125 mg/kg) followed by intravenous aminophylline (1.0 mg/kg), or were untreated. Although aminophylline improved some respiratory parameters, budesonide+aminophylline more effectively reduced intrapulmonary shunts and improved gas exchange, without significant cardiovascular effects. Combined treatment reduced lung edema and number of lung neutrophils to a higher extent than aminophylline alone. Both treatments reduced lung peroxidation and in vitro airway reactivity to histamine, with a better effect after aminophylline alone. Combination of budesonide and aminophylline enhanced respiratory parameters more effectively, having fewer side effects than aminophylline alone. However, no additive effect of budesonide was observed on lung peroxidation and in vitro airway reactivity.

The course of a respiratory disorder in a child may end up in respiratory failure. There are also acute non-respiratory diseases which have a great influence on the respiratory functions and often lead to the acute lung injury and sometimes to the acute respiratory distress syndrome (ARDS). A feature of respiratory function deterioration is changed in the surfactant system. We often see inhibition of its synthesis or damage to its structure. Therapy of children suffering from ARDS should be complex and rapid. Despite many recently published studies explaining the principle of this disorder, the mortality of ARDS is still very high (30-50%). There are several studies documenting successful administration of exogenous surfactant as part of a complex combined therapy of patients with ARDS, which leads to decreased mortality, improved oxygenation, and decreased need for aggressive artificial pulmonary ventilation. The authors of this article present their own experience with administration of exogenous surfactant in therapy of children with ARDS.

Among modern methods included in diagnostic algorithms for various diseases, analyses of expired breath and its condensate acquire increasing importance. Various markers can be determined in the exhaled air, especially volatile gaseous compounds: nitrogen oxide (NO), carbon monoxide (CO), hydrocarbons and 8-isoprostanes. In contrast to NO, CO can serve as a marker of inflammation and oxidation stress. The representation of CO in the exhaled breath (eCO) changes in various diseases of the respiratory and other systems. Among the respiratory diseases in which the use of eCO measurement seems to be perspective and beneficial are bronchial asthma, airways infections, cystic fibrosis, and primary ciliary dyskinesia. The observation of eCO concentrations represents a modern, simple, available, and well reproducible method for the diagnosis of many diseases of respiratory system in children and for the observation of progression, severity of the disease, and response to therapy.

The present study was aimed at the assessment of the impact of mother smoking during pregnancy on changes of phase angle (phi) and T(me)/T(E) index in healthy children. A hundred and twenty seven children, divided according to age (<6 months and >6 months of age) and mother smoking anamnesis were investigated by noncalibrated respiratory inductive plethysmography in the supine position. We found statistically significant changes of phi (p<0.05) and T(me)/T(E) in healthy children of non-smoking mothers against a group of smoking mother's children of up to 6 months of age. These differences were not confirmed in children older than 6 months. Moreover, in the smoking mother group, we found statistically significant changes (P<0.05) of phi and T(me)/T(E) in children of up to 6 months of age in comparison with children older than 6 month. The results revealed a negative impact of mother smoking during pregnancy represented by changes in airway obstruction parameters, which appeared especially in the group of youngest children.

Diabetic autonomic neuropathy (DAN) is manifested by dysfunction of one or more organ systems. Its subclinical form (sDAN) can be recognized with the use of noninvasive cardiovascular reflex tests. As the cough reflex is mediated via autonomic nervous system, there is a reason to suppose that it can also be changed due to presence of sDAN. The aim of the present study was to assess cough reflex sensitivity (CRS) in diabetic children with and without sDAN. A CRS test was performed in 35 children suffering from diabetes mellitus type 1 and the results were compared with those from age-matched 27 healthy children. Cough was induced by inhalation of capsaicin aerosol in doubling concentrations (0.61-1250 micromol/l) for 400 ms each. CRS was defined as the lowest capsaicin concentration that evoked 2 or more coughs (C2 parameter) and 5 or more coughs (C5 parameter). We found that CRS in the whole group of diabetic children was not significantly different from that in healthy children [diabetic children--C2: 75.1 micromol/l (95% CI: 42.0-134.2 micromol/l)] vs. healthy children--C2: 72.4 micromol/l (95% CI: 75.7-644.8 micromol/l)]. However, a significant decrease (P=0.005) in CRS was found in diabetic children with sDAN [n=12; C2: 221.0 micromol/l (95% CI: 75.7-644.8 micromol/l)] compared with diabetic children without sDAN [(n=23; C2: 42.7 micromol/l (95% CI: 23.1-79.0 micromol/l)]. We conclude that testing cough reflex sensitivity might be a way to establish the presence of diabetic neuropathy.