Mei-Jy Jeng

Spirometric pulmonary function parameters of healthy Chinese children aged 3–6 years in Taiwan†

Spirometry is a well‐known technique for evaluating pulmonary function, but few studies have focused on preschool children. The aim of this study was to determine reference values of forced spirometric parameters in young Chinese children, aged 3–6 years, in Taiwan. Spirometric measurements were performed at day care centers by experienced pediatricians. Of 248 children without a history of chronic respiratory illness, at least two valid spirometric attempts were obtained from 214 children (109 boys and 105 girls; age: 36–83 [mean = 61] months; height: 90–131 [mean = 111] cm). Values of forced expiratory volume in 1 sec (FEV1) and 0.5 sec (FEV0.5), forced vital capacity (FVC), peak expiratory flow rate (PEF), forced expiratory between 25% and 75% FVC (FEF25–75), and forced expiratory flow rate at 25%, 50%, and 75% of FVC (FEF25, FEF50, and FEF75) were derived and analyzed. There were significant positive correlations between study parameters and body height, body weight, and age. Height was the most consistently correlated measurement in both boys and girls. Although boys tended to have higher spirometric values than girls, we found significant differences only in FVC and FEV1 between boys and girls aged 6 years. The regression equations of each parameter were obtained. In conclusion, spirometric pulmonary function tests are feasible in 3‐ to 6‐year‐old children. The obtained values and regression equations provide a reference for Chinese preschool children and may be of value in evaluating pulmonary function of children with respiratory problems in this age group. Pediatr Pulmonol. 2009; 44:676–682.

Neonatal air leak syndrome and the role of high-frequency ventilation in its prevention

&NA; Air leak syndrome includes pulmonary interstitial emphysema, pneumothorax, pneumomediastinum, pneumopericardium, pneumoperitoneum, subcutaneous emphysema, and systemic air embolism. The most common cause of air leak syndrome in neonates is inadequate mechanical ventilation of the fragile and immature lungs. The incidence of air leaks in newborns is inversely related to the birth weight of the infants, especially in very‐low‐birth‐weight and meconium‐aspirated infants. When the air leak is asymptomatic and the infant is not mechanically ventilated, there is usually no specific treatment. Emergent needle aspiration and/or tube drainage are necessary in managing tension pneumothorax or pneumopericardium with cardiac tamponade. To prevent air leak syndrome, gentle ventilation with low pressure, low tidal volume, low inspiratory time, high rate, and judicious use of positive end expiratory pressure are the keys to caring for mechanically ventilated infants. Both high‐frequency oscillatory ventilation (HFOV) and high‐frequency jet ventilation (HFJV) can provide adequate gas exchange using extremely low tidal volume and supraphysiologic rate in neonates with acute pulmonary dysfunction, and they are considered to have the potential to reduce the risks of air leak syndrome in neonates. However, there is still no conclusive evidence that HFOV or HFJV can help to reduce new air leaks in published neonatal clinical trials. In conclusion, neonatal air leaks may present as a thoracic emergency requiring emergent intervention. To prevent air leak syndrome, gentle ventilations are key to caring for ventilated infants. There is insufficient evidence showing the role of HFOV and HFJV in the prevention or reduction of new air leaks in newborn infants, so further investigation will be necessary for future applications.

Effects of therapeutic bronchoalveolar lavage and partial liquid ventilation on meconium-aspirated newborn piglets.

Objective:To investigate the therapeutic effects of bronchoalveolar lavage (BAL) with either diluted surfactant (SBAL) or perfluorochemical liquid (PBAL), followed by either conventional mechanical ventilation (CMV) or partial liquid ventilation (PLV), on lung injury and proinflammatory cytokine production induced by meconium aspiration in newborn piglets. Design:A prospective, randomized, experimental study. Setting:An animal research laboratory at a medical center. Subjects:Anesthetized and mechanically ventilated newborn piglets (n = 27). Interventions:The animals were instilled with 3–5 mL/kg 25% human meconium via an endotracheal tube to induce meconium aspiration syndrome (MAS). After stabilization, animals were randomly assigned to either CMV group (no BAL) or one of the treatment groups (SBAL-CMV, SBAL-PLV, PBAL-CMV, and PBAL-PLV). Measurements and Main Results:Cardiopulmonary variables were monitored, and interleukin-1β and interleukin-6 content of the serum and lung tissue was measured. The animals without any treatment (CMV group) displayed the worst outcome; the animals in the PBAL-PLV group had the best gas exchange, lung compliance, and least pulmonary damage; and the SBAL-CMV, PBAL-CMV, and SBAL-PLV groups had intermediate effects. The serum interleukin-1β concentration of the CMV group was significantly higher than all other groups over time (p < .05), and interleukin-6 concentration was significantly higher than the PBAL-PLV group (p < .05). The tissue interleukin-1β and interleukin-6 contents were also highest in the CMV group and lowest in the PBAL-PLV group. Conclusions:Initial therapeutic BAL and therapeutic BAL followed by PLV with the same perfluorochemical liquid provided significant therapeutic effects in treating an animal model with severe MAS and therefore warrant consideration in cases that are intractable to other therapies.

Effects of exogenous surfactant supplementation and partial liquid ventilation on acute lung injury induced by wood smoke inhalation in newborn piglets.

ObjectiveTo investigate the beneficial effects of exogenous surfactant supplementation (ESS) and partial liquid ventilation (PLV) in treating acute lung injury induced by wood smoke inhalation. DesignA prospective, randomized, controlled, multigroup study. SettingAn animal research laboratory at a medical center. SubjectsNewborn piglets (n = 29; 1.80 ± 0.06 kg) of either sex. InterventionsAnimals were ventilated with a tidal volume of 15 mL/kg, a rate of 30 breaths/min, a positive end-expiratory pressure of 5 cm H2O, and an Fio2 of 1.0. After the induction of acute lung injury by wood smoke inhalation, animals were randomly assigned to receive either conventional mechanical ventilation (CMV) or PLV with or without ESS pretreatment. Animals were grouped as CMV, ESS-CMV, PLV, and ESS-PLV. Measurements and Main ResultsArterial blood gases, cardiovascular hemodynamics, dynamic lung compliance, and total lung injury scores were measured. After smoke inhalation, all four groups displayed similar high arterial carboxyhemoglobin levels, low Pao2 (<150 mm Hg), and low dynamic lung compliance (<66% of its baseline). In the CMV group, these deleterious conditions remained during the 4-hr observation period, and severe lung injury was noted histologically. All treatment groups demonstrated a significant increase in Pao2 compared with the CMV group. In addition, both the PLV and ESS-PLV groups displayed significant improvements in dynamic lung compliance and in their histologic outcomes. Nevertheless, none of the variables measured in the PLV group differed from those measured in the ESS-PLV group. ConclusionsIn a newborn piglet model of smoke inhalation injury, PLV or ESS improved oxygenation. PLV compared favorably with ESS in its greater improvements in lung compliance and lung pathology. However, the combined therapy of ESS and PLV was not clearly superior to PLV alone during the observation period.

Esophageal Atresia with Tracheoesophageal Fistula: Ten Years of Experience in an Institute

Background: Esophageal atresia (EA), tracheoesophageal fistula (TEF), or both is a complicated problem. The purpose of this study was to evaluate the outcomes and postoperative complications in patients with EA/TEF who were admitted to our hospital. Methods: In total, 15 patients were enrolled from 1994 to 2003, including 8 males and 7 females. Patient demographics, associated anomalies, and outcomes were analyzed. Results: The most common variant was EA with a distal TEF (type C), which occurred in 12 patients (80%). The latter had associated congenital anomalies, and cardiac anomalies were the most frequent, occurring in 8 patients (53.3%). Of the 6 cases who had life‐threatening anomalies, 4 (66.7%) died, and of the 9 cases who had no life‐threatening anomalies, 2 (22.2%) died. Tracheomalacia and/or stenosis were diagnosed in 8 patients (66.7%) postoperatively. Though 3 of the 4 cases who suffered from dying spell received intratracheal stent implantation, 2 cases still died. Conclusion: The survival rate of the patients with EA/TEF is influenced mainly by associated life‐threatening anomalies. TMS combined with a history of dying spell may be the major fatal complication.

Flexible bronchoscopy as a valuable diagnostic and therapeutic tool in pediatric intensive care patients: A report on 5 years of experience†

To evaluate the clinical role of flexible bronchoscopy (FB) in pediatric and neonatal intensive care units (ICUs).

Hyperbilirubinemia with urinary tract infection in infants younger than eight weeks old

Background: Hyperbilirubinemia is one of the most common causes for hospital admission in neonatal infants. Previous studies have found that jaundice may be one of the initial symptoms related to urinary tract infection (UTI) in infants. This study is to evaluate the incidence and related factors of neonatal infants with the initial presentation of hyperbilirubinemia and final diagnosis of UTI in a tertiary teaching hospital. Methods: We retrospectively investigated the medical records of admitted infants younger than 8 weeks old with hyperbilirubinemia between January and December 2008. The jaundiced infants having tests of urinalysis were enrolled into our study and grouped into UTI or no UTI group according to the findings of urinary culture. Results: A total of 217 neonatal jaundiced infants were enrolled. Among them, 12 cases (5.5%) were grouped into the UTI group, and the most common cultured bacterium from their urine was Escherichia coli. There was no significant difference in the babies’ birth weight, maternal conditions, or total bilirubin levels between the two groups. There was also no significant difference between the two groups in their admission age (9.7 ± 13.5 days vs. 6.1 ± 6.7 days in UTI and no UTI groups, respectively) or the ratio of outpatients (50% vs. 25% in UTI and no UTI groups, respectively) (p > 0.05). The cases of UTI group had significantly lower hemoglobin (15.2 ± 2.7 g/dL vs. 17.2 ± 2.3 g/dL, respectively) and higher formula feeding rate (8.3% vs. 2.9%, respectively) than the no UTI group (p < 0.05). Conclusion: The incidence of UTI in the admitted infants with hyperbilirubinemia was as high as approximately 5.5%. The most common cultured bacterium in urine was E coli. Therefore, performing urinary tests to exclude the possibility of coincidental UTI may be necessary for admitted jaundiced infants younger than 8 weeks old.

The epidemiology and prognostic factors of mortality in critically ill children with acute kidney injury in Taiwan

The incidence of acute kidney injury (AKI) in critically ill children varies among countries. Here we used claims data from the Taiwanese National Health Insurance program from 2006 to 2010 to investigate the epidemiological features and identify factors that predispose individuals to developing AKI and mortality in critically ill children with AKI. Of 60,338 children in this nationwide cohort, AKI was identified in 850, yielding an average incidence rate of 1.4%. Significant independent risk factors for AKI were the use of extracorporeal membrane oxygenation, mechanical ventilation or vasopressors, intrinsic renal diseases, sepsis, and age more than 1 year. Overall, of the AKI cases, 46.5% were due to sepsis, 36.1% underwent renal replacement therapy, and the mortality rate was 44.2%. Multivariate analysis showed that the use of vasopressors, mechanical ventilation, and hemato-oncological disorders were independent predictors of mortality in AKI patients. Thirty-two of the 474 patients who survived had progression to chronic kidney disease or end-stage renal disease. Thus, although not common, AKI in critically ill children still has a high mortality rate associated with a variety of factors. Long-term close follow-up to prevent progressive chronic kidney disease in survivors of critical illnesses with AKI is mandatory.

Cerebral oxygenation during hypoxia and resuscitation by using near-infrared spectroscopy in newborn piglets.

Background: Hypoxic events and cardiac arrest may cause brain damage in critical infants. This study investigated cerebral tissue oxygenation and oxygen extraction in a piglet model of hypoxic events, cardiac arrest and effects of resuscitation. Methods: For the hypoxia experiment, anesthetized newborn piglets were randomized to a hypoxia group (n = 8) with decreasing ventilatory rate to 0, and a control group (n = 8) with no hypoxic conditions. Regional cerebral tissue oxygen saturation (rScO2, detected by near‐infrared spectroscopy) and oxygen saturation were recorded every 5 minutes for 100 minutes. Fractional cerebral tissue oxygen extraction (FTOE) was calculated as (arterial oxygen saturation [SaO2]‐rScO2)/SaO2. For the resuscitation experiment, animals were grouped as hypoxia‐no CPR (n = 4), control‐no CPR (n = 4), and control‐CPR (n = 4) after cardiac arrest. Standard cardiopulmonary resuscitation (CPR) was performed on the control‐CPR group and observed for 30 minutes. Results: Immediate and significant changes in rScO2, and gradual changes in FTOE were observed during the hypoxia experiment. In the resuscitation experiment, no significant differences in rScO2 were found between groups. However, the highest FTOE was observed in the control‐CPR group. Conclusion: Noninvasive monitoring of rScO2 and evaluating FTOE changes during hypoxia and resuscitation may help clinicians evaluate brain tissue oxygenation and viability.

Pulmonary Function Changes in Children After Transcatheter Closure of Atrial Septal Defect

This study was performed to assess changes in pulmonary function test (PFT) and pulmonary outcome after transcatheter closure of atrial septal defect (ASD) in pediatric patients. A total 55 pediatric patients undergoing transcatheter ASD closure received PFT at baseline (day before ASD closure), and at 3 days and 6 months after procedure. Forced vital capacity (FVC), forced expired volume in 1 sec (FEV1), FEV1 to FVC ratio (FEV1/FVC), peak expiratory flow (PEF), and mean forced expiratory flow during the middle half of FVC (FEF25–75) were measured. Individually, subjects were classified by spirometry as normal, obstructive or restrictive, to evaluate the effect of transcatheter closure on pulmonary outcome. These 55 children had significantly reduced mean PEF and FEF25–75 (84 ± 24%, P = 0.040 and 76 ± 22%, P = 0.010, respectively) at baseline, with FEF25–75 reduced significantly at 3 days and 6 months (78 ± 24%, P = 0.010 and 81 ± 24%, P = 0.040, respectively) after transcatheter closure. Six months after transcatheter closure of ASD, significant improvement was observed in mean FVC (94 ± 19% vs. 98 ± 15%, P = 0.034) and FEV1 (90 ± 20% vs. 96 ± 19%, P = 0.008). Assessed individually, better pulmonary outcome was found in patients without pulmonary hypertension (PH) (χ2 = 8.333, P = 0.044). PFT disturbance was observed in significant flow limitation in the peripheral airway of ASD patients. Improved PFT was found after transcatheter closure and better pulmonary outcome was observed in patients without PH. ASD children need monitoring pulmonary function and should receive transcatheter closure before PH develops. Pediatr Pulmonol. 2009; 44:1025–1032. ©2009 Wiley‐Liss, Inc.