Environmental tobacco smoke exposure and respiratory syncytial virus infection in young children hospitalized with acute lower respiratory tract infection.

OBJECTIVE: The present study was performed to determine the relationship between environmental tobacco smoke (ETS) exposure and acute lower respiratory tract infection (LRI) caused by respiratory syncytial virus (RSV) in children. MATERIAL AND METHOD: The authors did the study in 71 children (median age 12 months; 60% male) who were admitted to King Chulalongkorn Memorial Hospital with acute LRI between June and September 2004. 27% had RSV infection. RESULTS: RSV-LRI required longer duration of oxygen therapy than non RSV-LRI (4.5 +/- 1.7 vs 2.8 +/- 1.3 days; p < 0.001). Desaturation in room air was more common in the former group compared to the latter group (37 vs 11%; p = 0.01). There was no difference in urinary cotinine level between the two groups (median 0.5 vs 0.6 mcg/mg Cr; ns). Among RSV-LRI, those with desaturation had higher urinary cotinine level than those without desaturation (median 0.8 vs 0.0 mcg/mg Cr; p = 0.04). CONCLUSION: ETS exposure was not associated with RSV-LRI but increased the risk of desaturation in these patients.

Restrictive lung disease and serum TGF-beta1 in thalassemia major children.

A cross sectional study was performed in 21 thalassemia major (TM) children at King Chulalongkorn Memorial Hospital during March to August, 2003 to determine whether restrictive lung disease (RLD) was related to serum transforming growth factor-beta 1 (TGF-beta1). All studied patients (57% female, age 11.2 +/- 2.6 yrs, duration of transfusion 7.7 +/- 4.1 yrs) never had desferoxamine treatment and their pulmonary function, serum ferritin and serum TGF-beta1 were evaluated. Five (24%) had RLD. RLD patients had significantly longer durations of transfusion and higher serum ferritin levels than non-RLD patients (9.1 +/- 1.9 vs 5.5 +/- 3.2 yrs; p = 0.03 and 3,816.6 +/- 1,715.9 vs 2,084.5 +/- 1,504.8 ng/ml; p = 0.04, respectively). TM children had lower serum TGF-beta1 levels than normal children (7.9 vs 78.8 pg/ml; p < 0.001). The serum TGF-beta1 level was not different between RLD and non-RLD patients (13.3 vs 4.2 pg/ml; ns), concluding that RLD was related to longer duration of transfusion and higher serum ferritin but not related to serum TGF-beta1 levels.

Plasma soluble intercellular adhesion molecule-1 (sICAM-1) in pediatric ARDS during high frequency oscillatory ventilation: a predictor of mortality.

Soluble intercellular adhesion molecule-1 (sICAM-1), an important adhesion molecule that mediates leukocyte-endothelial interaction, has been identified as a marker for the outcome of acute respiratory tract infection. We postulate that plasma ICAM-1 may be a valuable marker for both biological and clinical severity of acute respiratory distress syndrome (ARDS). Sixteen pediatric patients (> 1 month and < 15 years of age) diagnosed with ARDS were recruited from the Pediatric Intensive Care Unit at King Chulalongkorn Memorial University Hospital, Bangkok. The patients were randomized to receive either high frequency oscillatory ventilation (HFOV) or conventional mechanical ventilation. Plasma sICAM-1 was measured by enzyme linked immunosorbent assay (ELISA) on days 1, 3, 5 and 7 of ARDS. Plasma sICAM-1 levels in survivors and non-survivors of the HFOV and conventional treatment groups were compared. Nine and 7 patients constituted the control group receiving conventional treatment and HFOV group, respectively. Overall nine patients survived. The patients in the HFOV group had a better chance of survival compared to the controls (71% versus 31.5%), but it was not statistically significant (p = 0.2). The overall mortality was 45.7%. The mean plasma sICAM-1 levels (n = 13/16) were significantly elevated among non-survival patients as compared to survival patients at all time points, which indicates that an unfavorable outcome in ARDS is related to the degree of epithelial and endothelial alveolar cell injury. The elevation of plasma slCAM-1 on day 3 provided the best predictor of mortality (likelihood ratio 11.9, p < 0.001). It was concluded that HFOV facilitated a potentially better outcome compared to conventional treatment and it was associated with less lung injuries evidenced by lower plasma sICAM-1.

Validity of tidal breathing flow volume loops in diagnosing obstructive sleep apnea in young children with adenotonsillar hypertrophy: a preliminary study.

Tidal breathing flow volume loops (TBFVL) can indicate the site/severity of upper airway obstruction (UAO). The authors did a pilot study to determine 1) the correlation between TBFVL and obstructive sleep apnea (OSA) as well as its severity and 2) the validity of TBFVL in determining OSA and desaturation during sleep in young children with a denotonsillar hypertrophy (ATH). A cross sectional analytical study was performed in 10 patients with ATH (age 4.2 +/- 0.4 yrs; 40% female) at King Chulalongkorn Memorial Hospital during January-June 2004. All had polysomnography and TBFVL performed during sleep. Median apnea/hypopnea index (AHI) was 3.4/hr. Eight (80%) patients had OSA. The TBFVL was normal in 2, variable UAO in 3, and fixed UAO in 5 patients. Among these 3 groups, the number of OSA patients (2, 3 and 3, respectively; ns) and the number of those who had desaturation (2, 3 and 3, respectively; ns) were not different. There was no correlation between mid tidal expiratory flow rate/mid tidal inspiratory flow rate (Me/Mi) ratio and AHI (r=0.5; ns) or lowest arterial oxygen saturation during sleep (r=-0.4; ns). The accuracy of Me/Mi > 1.5 for diagnosing OSA and desaturation was 50% and 60%, respectively. The abnormal TBFVL also had the same accuracy in defining these 2 conditions. In conclusion, TBFVL did not correlate with OSA and its severity and had low accuracy in determining either OSA or desaturation in young children with ATH.

Plasma endothelin-1 in infants and young children with acute bronchiolitis and viral pneumonia.

Respiratory syncytial virus (RSV) Infections that occur during the first three years of life have been demonstrated to be associated with the development of childhood asthma. The mechanism of virus-triggered airway inflammation Is not fully understood. Endothelin-1 is a potent bronchoconstrictor involved in many diseases including respiratory tract infections. Infants and young children diagnosed with either viral pneumonia or acute bronchiolitis, their age ranging between 2 months and 3 years, were recruited into this study. Nasopharyngeal aspirates were taken for detection of respiratory virus by antigen immunofluorescence stain, RT-PCR analysis and viral culture. Plasma endothelin-1 (ET-1) was measured by using a commercially available enzyme-linked immunosorbent assay (ELISA). Ten of the nineteen infants and children (52%) were positive for RSV infection, one co-infected with influenza A. Nine Infants (90%) were positive for RSV subtype A. There was only one infant with subtype B. One of the RSV negative individuals was positive for influenza A. In addition, we recruited 10 patients without chronic underlying or respiratory tract illness as controls. ET-1 levels were significantly increased in RSV infection compared to the controls (3.6 +/- 1.2 and 1.2 +/- 1 pg/ml, respectively (p < 0.05). In conclusion, infants and young children who are infected with RSV have an increase in circulating plasma endothelin-1. This in turn may contribute to the subsequent development of childhood asthma.