The long duration of extracorporeal membrane oxygenation in a child with acute severe hypoxic respiratory failure treated in a resource-limited center

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) has been indicated in patients with severe refractory respiratory failure from various causes for more than 30 years, even for the small infant.(1) Improved outcome from using ECMO for respiratory failure has been reported worldwide, ranging from 15% to over 50% in recent reviews.(1,2) The rationale of this therapy is to allow time for the lungs to heal, minimizing further lung injury from positive pressure ventilation.(3,4) We describe a case of severe acute respiratory distress syndrome (ARDS) with extensive barotrauma supported by VV-ECMO for 96 days in a resource-limited center. This is likely the longest ECMO support ever reported in a child.

Prevalence, clinical presentations and complications among hospitalized children with influenza pneumonia

Viral respiratory tract infections are a major cause of hospitalization in children. Influenza is common but often not laboratory proven. We report a prospective study of children admitted with a clinical diagnosis of pneumonia. Infants and children (ages 1 month-15 years) who were hospitalized with community-acquired pneumonia were enrolled in the study. Their nasopharyngeal aspirated samples were analyzed for common respiratory viruses, including influenza virus, by reverse transcription-polymerase chain reaction (RT-PCR) or PCR. Out of 257 patients, we identified 127 (49.4%) cases with respiratory viruses, and influenza was found in 32 of these cases (12.5%). Other common respiratory viruses included respiratory syncytial virus in 42 (16.3%), human metapneumovirus in 24 (9.3%), adenovirus in 17 (6.6%) and parainfluenza virus in 12 (4.7%). The median age of the influenza group was 2 years and 3 months, and 27 (84%) of children in this group were under the age of 5. Asthma was the most common co-morbidity (4/32, 12.5%). Common clinical presentations were fever and cough (100%) with crepitations (90%). The median length of hospitalization was 6 days. Three patients developed respiratory failure, with one mortality (3.1%). One child developed infection-associated hemophagocytic syndrome. Our study demonstrated that young children had a high risk of hospitalization due to influenza pneumonia, which contributed to a significant morbidity.

Randomized controlled trial of salbutamol aerosol therapy via metered dose inhaler-spacer vs. jet nebulizer in young children with wheezing

The jet nebulizer is a common device used for administering aerosol medication in young children. However, compared to a metered dose inhaler-spacer (MDI-spacer), it takes more time and personnel. This study aimed to compare the efficacy of salbutamol aerosol therapy given via these two devices in young wheezing children. A prospective randomized, double-blind, placebo-controlled trial was performed in children up to 5 years old who had acute wheezing and were admitted to the Department of Pediatrics, King Chulalongkorn Memorial Hospital. Patients were randomly divided into two groups. The first group received 2 puffs of placebo via MDI-spacer, followed by 0.15 mg/kg salbutamol respiratory solution via jet nebulizer. The second group received 2 puffs (100 microg/puff) of salbutamol via MDI-spacer, followed by placebo via jet nebulizer. Clinical scores and tidal breathing pulmonary function test were evaluated before and after treatment. Pulmonary function parameters included those derived from flow volume loops (volume to peak tidal expiratory flow over total expiratory volume, V(PTEF)/V(E); time to peak tidal expiratory flow over total expiratory time, T(PTEF)/T(E); and ratio of tidal expiratory flow at 25% remaining expiration to peak expiratory flow, 25/PF), compliance (Crs), and resistance (Rrs) of the respiratory system. The efficacy of both methods was compared by using analysis of covariance. Forty-seven wheezing children were studied (24 received salbutamol via MDI-spacer, and 23 received it via jet nebulizer). There was no statistical difference between the two groups regarding clinical scores and all pulmonary function parameters. However, heart rate was significantly increased after treatment in the jet nebulizer group when compared to those in the MDI-spacer group (P = 0.004). In conclusion, the efficacy of salbutamol aerosol therapy via MDI-spacer compared to jet nebulizer in young wheezing children was not different in terms of clinical score and postbronchodilator pulmonary function parameters. However, salbutamol aerosol therapy via jet nebulizer significantly increased the heart rate when compared to the MDI-spacer.

Plasma endothelin-1 levels in patients with biliary atresia: possible role in development of portal hypertension

BACKGROUND

Biliary atresia (BA) is a severe neonatal liver disease characterized by progressive extrahepatic biliary tract and intrahepatic inflammatory process. Hepatic fibrosis and portal hypertension (PH) still occur despite the disappearance of jaundice following successful hepatic portoenterostomy. Endothelin-1 (ET-1) is a potent vasoconstrictor and has been reported to stimulate hepatic collagen synthesis. The aim of this study was to demonstrate the potential role of ET-1 in the pathogenesis of the progressive inflammation, fibrosis and PH in BA.

METHODS

Thirty pediatric patients with biliary atresia post-hepatic portoenterostomy and 12 healthy children were examined. The ET-1 level was determined by commercially available enzyme-linked immunosorbent assay kits.

RESULTS

Endothelin-1 levels were elevated in the patients compared with those of the controls (5.45+/-3.34 vs. 2.74+/-2.17 pg/ml, P = 0.01). Moreover, patients with PH also had greater levels of ET-1 than those without PH (6.73+/-3.27 vs. 3.26+/-2.2 pg/ml, P = 0.004). Patients with abnormal transaminase enzymes had significantly higher ET-1 levels than those with normal enzymes (6.43+/-3.33 vs. 3.17+/-2.1 pg/ml, P = 0.01). In the jaundice-free group, endothelin-1 levels were elevated in the patients with PH compared with those without PH (5.93+/-2.15 vs. 2.88+/-2.1 pg/ml, P = 0.02).

CONCLUSIONS

Our findings showed elevation of plasma ET-1 levels in patients with BA, especially in those with PH. ET-1 levels were also higher in patients with elevated transminase enzymes as well as in the jaundice-free group with PH. ET-1 might play a role in the pathogenesis of the progressive inflammation, fibrosis and PH in BA.

Modulation of endothelin-1 expression in pulmonary epithelial cell line (A549) after exposure to RSV

Respiratory syncytial virus (RSV) is one of the most important respiratory tract pathogens in infants and young children. The airway epithelial cells are the primary target cells for RSV infection. The airway epithelial layer is not only a physical barrier, but also plays a role in a synthesis of a variety of major inflammatory cytokines (IL-6, IL-8, GM-CSF etc.) as previously reported. Endothelin-1 (ET-1) is a potent bronchoconstrictor and vasoconstrictor factor, and involved in pathogenesis of various diseases of the respiratory tract. We hypothesized that RSV may induce the release of ET-1 from the bronchial epithelial cell line. No previous data is available regarding association between RSV infection and ET-1 release. We evaluated the effect of RSV with different concentrations of RSV (MOI 0.1, 1 and 3 pfu/cell) on bronchial epithelial cell line (A549) and measured the production of ET-1 at both protein and mRNA level. A549 cells were treated with different conditions by using LPS, heat-inactivated RSV, RSV or medium alone as control. We observed time-dependent ET-1 release by RSV-infected A549 cells at 4 h, 24 h and maximum at 72 h. ET-1 was expressed in unstimulated A549 cells and was further increased by RSV. RSV with concentration MOI 0.1 (pfu/cell) and LPS appeared to have strongest stimulation on production of ET-1. In addition, ET-1 mRNA was increased significantly by 16 h and decreased to relatively low-level at 24 h. These experiments suggested that airway epithelial cells might play a role in the local airway smooth muscle tone through the production of endothelin-1 during RSV infection.