Weaning strategies for children on home invasive mechanical ventilation.

Children who require home mechanical ventilation (HMV) with an artificial airway or invasive mechanical ventilation (HMV) have a possibility of successful weaning due to the potential of compensatory lung growth. Internationally accepted guidelines on how to wean from HMV in children is not available, we summarize the weaning strategies from the literature reviews combined with our 27-year experience in the Pediatric Home Respiratory Care program at the tertiary care center in Thailand. The readiness to wean is considered in patients with hemodynamic stability, having effective cough measured by maximal inspiratory pressure, requiring a fraction of inspired oxygen (FiO2) < 40%, positive end expiratory pressure <5 cmH2O, and acceptable arterial blood gases. The strategies of weaning is start weaning during the daytime while the child is awake and close monitoring is feasible. Disconnect time is gradually increased through naps and sleeping hours. Weaning from the conventional mechanical ventilator to Bilevel PAP or CPAP are optional. Factors affected the successful weaning are mainly the underlying diseases, complications, growth and development, caregivers, and resources. Weaning should be stopped during acute illness or increased work of breathing. The readiness for decannulation could be determined by using the speaking devices, tracheostomy capping, and measurement of end-expiratory pressure. Polysomnography and airway evaluation by bronchoscopy are recommended before decannulation. Weaning when the child is ready is crucial because living with HMV can be challenging and stressful. Failure to remove a tracheostomy when indicated can result in delayed speech, social problems as well as risk for infection.

Long-term sleep apnea CPAP via tracheostomy in children with tracheomalacia: 20-year experience.

Introduction: Children with severe tracheobronchomalacia may need placements of tracheostomies and long-term mechanical ventilation. Due to financial constraints, continuous positive airway pressure (CPAP) machines commonly used to treat obstructive sleep apnea in adults have been utilized to deliver positive distending pressure to such children at our institution for more than 20 years with favorable outcomes. We, therefore, reported our experience with 15 children using this machine. Methods: This is a retrospective study during 2001-2021. Results: Fifteen children, 9 boys, aged ranged 3 months-5.6 years, were discharged home with CPAP via tracheostomies. All had co-morbidities including gastroesophageal reflux (n = 9, 60%), neuromuscular disorders (n = 6, 40%), genetic abnormalities (n = 6, 40%), cardiac diseases (n = 4, 27%) and chronic lungs (n = 3, 20%). Eight (53%) children were aged less than 1 year old. The smallest child was aged 3 months old, weighing 4.9 kg. All caregivers were relatives and non-medical health professionals. The 1-month and 1-year readmission rates were 13% and 66% respectively. No factor-associated unfavorable outcomes were statistically identified. No complications related to CPAP malfunction were found. Five (33%) were weaned off CPAP, and 3 died (2 from sepsis and 1 from a sudden unknown cause). Conclusion: We first reported the use of sleep apnea CPAP via tracheostomy in children with severe tracheomalacia. In limited-resource countries, this simple device may be another option for long-term invasive ventilatory support. The CPAP use in children with tracheobronchomalacia requires adequately trained caregivers.

Treatment of obstructive sleep apnea in high risk pregnancy: a multicenter randomized controlled trial.

BACKGROUND: Obstructive sleep apnea (OSA) during pregnancy is a risk factor for preeclampsia possibly through a link to placental physiology. This study evaluates the efficacy of continuous positive airway pressure (CPAP) on the modulation of blood pressure and the reduction in preeclampsia in women with high-risk pregnancy and OSA. METHODS: A multicenter open-label, randomized controlled trial comparing CPAP treatment versus usual antenatal care was conducted in three academic hospitals in Bangkok, Thailand. Participants included singleton pregnant women aged older than 18 years with any high-risk condition (i.e., chronic hypertension, obesity, history of preeclampsia or gestational diabetes in the previous pregnancy, or diabetes), and OSA (respiratory disturbance index 5-29.99 events/hour by polysomnography), who presented either in the first trimester (gestational age, GA 0-16 weeks) or subsequently developed OSA during the 2nd trimester (GA 24-28 weeks). The primary endpoint was blood pressure during antenatal care. Secondary endpoints included the incidence of preeclampsia. An intention-to-treat analysis was performed with additional per-protocol and counterfactual analyses for handling of nonadherence. RESULTS: Of 340 participants, 96.5% were recruited during the first trimester. Thirty participants were later excluded leaving 153 and 157 participants in the CPAP and usual-care groups for the modified-intention-to-treat analysis. CPAP adherence rate was 32.7% with average use of 2.5 h/night. Overall, CPAP treatment significantly lowered diastolic blood pressure (DBP) by - 2.2 mmHg [95% CI (- 3.9, - 0.4), p = 0.014], representing approximately - 0.5 mmHg per hour of CPAP use [95%CI (- 0.89, - 0.10), p = 0.013]. CPAP treatment also altered the blood pressure trajectory by continuously lowering DBP throughout pregnancy with mean differences (95% CI) of - 3.09 (- 5.34, - 0.93), - 3.49 (- 5.67, - 1.31) and - 3.03 (- 5.20, - 0.85) mmHg at GA 18-20, 24-28, and 32-34 weeks, respectively compared to 0-16 weeks. Preeclampsia rate was 13.1% (20/153 participants) in the CPAP and 22.3% (35/157 participants) in the usual-care group with a risk difference (95% CI) of - 9% (- 18%, - 1%, p-value = 0.032) and a number-needed-to-treat (95% CI) of 11 (1, 21). CONCLUSIONS: CPAP treatment in women with even mild-to-moderate OSA and high-risk pregnancy demonstrated reductions in both DBP and the incidence of preeclampsia. CPAP treatment also demonstrated a sustained reduction in DBP throughout gestation. Trial registration ClinicalTrial.GovNCT03356106, retrospectively registered November 29, 2017.

Modified high-flow nasal cannula for children with respiratory distress.

BACKGROUND: High-flow nasal cannula (HFNC) is a noninvasive respiratory support that provides the optimum flow of an air-oxygen mixture. Several studies demonstrated its usefulness and good safety profile for treating pediatric respiratory distress patients. However, the cost of the commercial HFNC is high; therefore, the modified high-flow nasal cannula was developed. PURPOSE: This study aimed to compare the effectiveness, safety, and nurses' satisfaction of the modified system versus the standard commercial HFNC. METHODS: This prospective comparative study was performed in a tertiary care hospital. We recruited children aged 1 month to 5 years who developed acute respiratory distress and were admitted to the pediatric intensive care unit. Patients were assigned to 2 groups (modified vs. commercial). The effectiveness and safety assessments included vital signs, respiratory scores, intubation rate, adverse events, and nurses' satisfaction. RESULTS: A total of 74 patients were treated with HFNC. Thirty- nine patients were assigned to the modified group, while the remaining 35 patients were in the commercial group. Intubation rate and adverse events did not differ significantly between the 2 groups. However, the commercial group had higher nurses' satisfaction scores than the modified group. CONCLUSION: Our findings suggest that our low-cost modified HFNC could be a useful respiratory support option for younger children with acute respiratory distress, especially in hospital settings with financial constraints.

Homemade valved holding chambers for children with airway hyperresponsiveness: A randomized crossover trial.

BACKGROUND: During the COVID-19 pandemic, a metered-dose inhaler (MDI) with a valved holding chamber (VHC) is a preferred route of bronchodilator delivery. We have developed a new homemade VHC, made of a paper coffee cup, and a drinking water bottle. This study was conducted to compare the bronchodilator response in children with airway hyperresponsiveness after the use of our homemade VHC and that of a standard commercial one. METHODS: In a randomized, two-period, two-sequence crossover trial, we recruited 20 children, aged 6-15 years, who had a greater than 12% increase in FEV1 after inhaled salbutamol. They were randomized into Group A and B. Group A used our VHC on the first day and Aerochamber® on the second day. Group B used the same VHCs but in alternate sequence. Spirometries were performed before and after 400 µg of salbutamol, MDI was administered via those VHCs. RESULTS: Baseline demographic data and spirometric values did not have statistically significant differences between group A and B and between the first and second day (p > .05). After giving salbutamol MDI, both VHCs produced significant increases in FVC, FEV1 , and FEF25-75% (p < .005). The improvement in FEV1 did not significantly differ between our homemade VHC and Aerochamber® (p > .05). CONCLUSION: Our homemade VHC is effective for an MDI bronchodilator delivery. Since it is very cheap and easy to make, it may be used as a disposable device to minimize airborne transmission especially when commercial VHC is not available.

Can standard deviation of overnight pulse oximetry be used to screen childhood obstructive sleep apnea.

OBJECTIVES: Pulse oximetry (PO) has been frequently used as an alternative test to polysomnography (PSG) in children. We conducted this study to determine which statistical parameters obtained from overnight PO monitoring would be most suitable and to evaluate its diagnostic performance. METHODS: We prospectively recruited children with snoring referred for PSG. Subjects were monitored with PO while performing PSG. Eight statistical parameters of SpO2 data were analyzed to identify which had the best diagnostic performance as assessed by the area under the receiver-operating characteristic curve (AUC). To validate this parameter (which was found to be the standard deviation, SD) in a larger population, we retrospectively extracted raw data of SpO2 from our previous PSG records, calculated the SD of each patient, and assessed its AUC. RESULTS: A total of 166 children were recruited in the first phase. SD of SpO2 was found to have the largest AUC. In the second phase, raw data of 457 patients were extracted. SD of SpO2 correlated well with the apnea/hypopnea index (AHI) (r = 0.6, P < 0.001). For diagnosis of moderate to severe obstructive sleep apnea (OSA) (AHI ≥5 events/h), AUC was 0.74. SD of SpO2 ≥1.06 representing mean + 2SD of normal to mild OSA (AHI <5) provided 97% specificity and 92% positive predictive value. The positive likelihood ratio was 11. CONCLUSION: Calculating the SD of SpO2, which quantifies the amount of dispersion of SpO2 values, is a useful initial investigation in childhood OSA. An SD ≥ 1.06 can predict moderate to severe OSA with confidence. This parameter is simple, practical, and readily accessible.

Clinical and Pathological Correlation in Pediatric Invasive Pulmonary Aspergillosis.

INTRODUCTION: Invasive' pulmonary aspergillosis (IPA) has been one of the major causes of mortality in immunocompromised patients. The gold standard method for a diagnosis of IPA is histopathological examination of the lung tissue; however, post-procedural bleeding limits the feasibility of lung biopsy. The European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and The National Institute of Allergy and Infectious Disease Mycoses Study Group (EORTC/MSG) defined IPA. The objective of this study was to validate the EORTC/MSG 2008 definition of IPA, compared with histopathology in the pediatric population. METHODS: Histopathological examinations of lung tissues of children aged 1 month-18 years with respiratory tract infection at the time of obtaining biopsy were retrieved. Retrospective chart reviews for clinical characteristics were performed. IPA diagnosis was classified according to the EORTC/MSG 2008 definition. RESULTS: During the 10-year period, there were 256 lung tissues, of which 58 specimens were suspected to have pulmonary infection. Fourteen patients (24%) were noted to have IPA. Seven patients (50%) with proven IPA were classified as probable, while the remaining 50% were classified as possible, and none were classified as no IPA, by using EORTC/MSG 2008 definition. Other 44 specimens demonstrated 14 (32%), 14 (32%), and 16 (36%) were classified as probable, possible, and no IPA, respectively. When comparing probable or possible IPA with no IPA, we found that the EORTC/MSG 2008 definition had 100% sensitivity, 36% specificity, 33% positive predictive value, and 100% negative predictive value in diagnosis of IPA. CONCLUSION: Our study illustrated that the EORTC/MSG 2008 definition provided an excellent sensitivity but low specificity for diagnosing IPA.

The effectiveness of newly developed written asthma action plan in improvement of asthma outcome in children.

BACKGROUND: Providing asthma education about controller medication use and appropriate management of asthma exacerbation are the keys to improving the disease outcome. Many asthma guidelines recommend that physicians provide written asthma action plan (WAAP) to all of their asthmatic patients. However, the benefit of WAAP is unclear. Thus, we have created a new WAAP which is simplified in Thai and more user friendly. OBJECTIVE: To determine the effectiveness of the newly developed asthma action plan in management of children with asthma. METHODS: Asthmatic children who meet inclusion criteria all received the WAAP and they were followed up for 6 months with measurement of outcome variables, such as asthma exacerbation that required emergency room visit, unscheduled OPD visit, admission and school absence in order to compare with the past 6 months before receiving the WAAP. RESULTS: The analyzed outcomes of forty-nine children show significantly reduced emergency room visit (P-value 0.005), unscheduled OPD visit (P-value 0.046), admission days (P-value 0.026) and school absence days (P-value 0.022). Well controlled group and mild severity group were not the factors that contribute to decreased emergency room visit but step up therapy may be the co-factor to decreased ER visit. CONCLUSIONS: The results of this study suggest that the provision of newly developed WAAP is useful for improving self- care of asthma patients and reducing asthma exacerbation.

Thai pediatricians' current practice toward childhood asthma.

BACKGROUND: Childhood asthma is a substantial health burden in Thailand. Due to a lack of pediatric respiratory specialists (pediatric pulmonologists and allergists; RS), most Thai children are cared for by general pediatricians (pediatric primary care providers (PCP)). OBJECTIVES: We investigated whether current practices of Thai pediatricians complied with asthma guidelines and compared practices (diagnosis and treatments) provided by PCP and RS. METHODS: A cross-sectional study was conducted using electronic surveys including four case scenarios of different asthma phenotypes distributed to Thai pediatricians. Asthma diagnosis and management were evaluated for compliance with standard guidelines. The practices of PCP and RS were compared. RESULTS: From 800 surveys distributed, there were 405 respondents (51%). Most respondents (81%) were PCP, who preferred to use clinical diagnosis rather than laboratory investigations to diagnose asthma. For acute asthmatic attacks, 58% of the pediatricians prescribed a systemic corticosteroid. For uncontrolled asthma, 89% of the pediatricians prescribed at least one controller. For exercise-induced bronchospasm, 55% of the pediatricians chose an inhaled bronchodilator, while 38% chose a leukotriene receptor antagonist (LTRA). For virus-induced wheeze, 40% of the respondents chose an LTRA, while 15% chose inhaled corticosteroids (ICS). PCP prescribed more oral bronchodilators (31% vs. 18%, p = 0.02), antibiotics (20% vs. 6%, p < 0.001), and antihistamines (13% vs. 0%, p = 0.02) than RS for the management of an acute asthmatic attack. CONCLUSIONS: Most of the Thai pediatricians' practices toward diagnosis and treatment of acute asthmatic attack and uncontrolled asthma conform to the guidelines. PCP prescribed more oral bronchodilators, antibiotics, and antihistamines than RS.

Home Mechanical Ventilation in Children.

The number of children dependent on home mechanical ventilation has been reported to be increasing in many countries around the world. Home mechanical ventilation has been well accepted as a standard treatment of children with chronic respiratory failure. Some children may need mechanical ventilation as a lifelong therapy. To send mechanically ventilated children back home may be more difficult than adults. However, relatively better outcomes have been demonstrated in children. Children could be safely ventilated at home if they are selected and managed properly. Conditions requiring home ventilation include increased respiratory load from airway or lung pathologies, ventilatory muscle weakness and failure of neurologic control of ventilation. Home mechanical ventilation should be considered when the patient develops progressive respiratory failure or intractable failure to wean mechanical ventilation. Polysomnography or overnight pulse oximetry plus capnometry are used to detect nocturnal hypoventilation in early stage of respiratory failure. Ventilator strategy including non-invasive and invasive approach should be individualized for each patient. The author strongly believes that parents and family members are able to take care of their child at home if they are trained and educated effectively. A good team work with dedicated members is the key factor of success.

Using non-invasive bi-level positive airway pressure ventilator via tracheostomy in children with congenital central hypoventilation syndrome: two case reports.

INTRODUCTION: Due to the economic downturn in Thailand, two baby girls with congenital central hypoventilation syndrome had to wait for several months to obtain definite diagnosis and long-term mechanical ventilation. Genetic investigation later revealed 20/25 polyalanine expansion of PHOX2B gene in both girls. In this report we highlight the use of non-invasive bi-level positive airway pressure ventilators via tracheostomy, overnight end-tidal carbon dioxide trend graphs and outcomes of the patients whose diagnosis and treatment were delayed. CASE PRESENTATION: Case 1: A Thai baby girl showed symptoms of apnea and cyanosis from birth and required invasive mechanical ventilation via tracheostomy during sleep. At 5 months, she unfortunately was discharged from the hospital without any ventilatory support due to financial problems. She subsequently developed cor pulmonale, respiratory failure and generalized edema and was referred to us when she was 9-months old. An overnight polysomnogram was consistent with a central hypoventilation disorder, in which the severity of oxygen desaturation and hypercapnia was worsening during non-rapid eye movement compared to rapid eye movement sleep. At 12 months she was allowed to go home with a conventional home ventilator. The ventilator was changed to bi-level positive airway pressure when she was 4-years old. After she received adequate home ventilation, she thrived with normal growth and development. Case 2: A Thai baby girl developed apnea and cyanosis from the age of 5 weeks, requiring ventilatory support (on and off) for 5 months. After being extubated, she had been put on supplemental oxygen via nasal cannula for 2 months. She was then referred to us when she was 7-months old. An overnight end-tidal carbon dioxide trend graph revealed marked hypercapnia without increase in respiratory rate. An overnight polysomnogram was consistent with a central hypoventilation disorder. Since 9 months of age she has been on home bi-level positive airway pressure via tracheostomy without any complications. Genetic testing confirmed 20/25 polyalanine expansions of PHOX2B gene in both girls. CONCLUSIONS: Bi-level positive airway pressure, originally designed as a non-invasive ventilator, was found to work effectively and safely, and may be used as an invasive ventilator via tracheostomy in young children with congenital central hypoventilation syndrome.

Reliability and validity of Thai version Quality of Life Questionnaire (OSA-18) for pediatric obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a chronic illness affecting either cardiopulmonary or neuropsychiatric function. Besides the functional health, the quality of life of patients with obstructive sleep apnea (OSA) is of interest in literature. In children, the quality of life questionnaire, which consists of 18 items (OSA-18), has been widely accepted as a reliable, valid, and simple to administer. This questionnaire may also be useful in Thai children with OSA. OBJECTIVE: To assess the reliability and validity of the Thai version of OSA-18 in Thai children. MATERIAL AND METHOD: This was a cross-sectional study. The original English version of the 18-item pediatric obstructive sleep apnea quality of life questionnaire was translated into Thai following the guidelines of cross-cultural adaptation with permission from Rosenfeld RM, Department of Otolaryngology, SUNY Health Science Center at Brooklyn, USA. The questionnaire was divided into five domains, sleep disturbance, physical suffering, emotional distress, daytime problems, and caregiver concerns. The suspected obstructive sleep apnea children, aged less than 15 years, who did not have cardiovascular diseases, lung diseases, or neuromuscular diseases, and who underwent standardfull night polysomnography were included. The child's caregiver was asked to complete the questionnaire without assistance to determine its reliability and validity. RESULTS: Forty-three children (30 boys, and 13 girls) were enrolled in the present study. The median age was five years (range 2 to 14 years). The median apnea hypopnea index (AHI) was six events/hour and median OSA-18 total score was 66.7 (range 25 to 107). There were excellent test-retest reliability (Cronbach's alpha = 0.91) and internal consistency (Cronbach's alpha = 0.77) between each domain. Correlation between the Thai OSA-18 total scores and AHI was r = 0.48, p = 0.001, which was similar to the original English version (r = 0.43, p < 0.001). CONCLUSION: The level of reliability and validity of the Thai version of the OSA-18 has been found to be satisfactory. Therefore, this instrument can be used in future research for measuring the quality of life in Thai children with OSA and assess the benefit of treatment.

QT dispersion in childhood obstructive sleep apnoea syndrome.

The difference between maximal and minimal QT interval and corrected QT interval defined as QT dispersion and corrected QT dispersion may represent arrhythmogenic risks. This study sought to evaluate QT dispersion and corrected QT dispersion in childhood obstructive sleep apnoea syndrome. Forty-four children (34 male) with obstructive sleep apnoea syndrome, aged 6.2 plus or minus 3.5 years along with 38 healthy children (25 male), 6.6 plus or minus 2.1 years underwent electrocardiography to measure QT and RR intervals. Means QT dispersion and corrected QT dispersion were significantly higher in obstructive sleep apnoea syndrome than controls, 52 plus or minus 27 compared to 40 plus or minus 14 milliseconds (p equal to 0.014), and 71 plus or minus 29 compared to 57 plus or minus 19 milliseconds (p equal to 0.010), respectively. Interestingly, QT dispersion and corrected QT dispersion in obstructive sleep apnoea syndrome with obesity, 57 plus or minus 30 and 73 plus or minus 31 milliseconds, were significantly higher than in control, 40 plus or minus 14 and 57 plus or minus 19 milliseconds (p equal to 0.009 and 0.043, respectively). However, QT dispersion and corrected QT dispersion in obstructive sleep apnoea syndrome without obesity, 43 plus or minus 20 and 68 plus or minus 26 milliseconds, were not significantly different. In conclusion, QT dispersion and corrected QT dispersion were significantly increased only in childhood obstructive sleep apnoea syndrome with obesity. Obesity may be the factor affecting the increased QT dispersion and corrected QT dispersion.

Ketotifen versus inhaled budesonide for controlling childhood asthma.

BACKGROUND: International asthma guideline recommends inhaled corticosteroids therapy for children of all ages as the first controller. However, in some less developed parts of the world, ketotifen, an old inexpensive medicine with antihistaminic and anti-allergic reactions, has been found to be the most favored prophylactic agents. OBJECTIVE: To compare the efficacy and safety of ketotifen and inhaled budesonide in asthmatic children aged 8 months to 14 years at Banpong Hospital, located 80 km south from Bangkok. MATERIAL AND METHOD: Children who had been admitted with acute asthmatic attack in 2008 at Banpong Hospital and had > 3 episodes of wheeze with good response to nebulized bronchodilators were randomized into two groups. Ketotifen group (n = 16) were given oral ketotifen 0.5 mg or 1 mg twice daily depending on age. Budesonide group (n = 14) were given as inhaled budesonide 200 microg (MDI) twice daily. Caregivers recorded children's asthmatic symptoms and nebulized treatments in diaries every day. The enrolled children received these two treatment regimens and were followed up for 26 weeks. RESULTS: Number of ER visits decreased significantly after both treatments (p < 0.005). The percentage of children with reduction in ER visits was comparable between ketotifen and budesonide (p = 0.16). Ketotifen group also demonstrated a reduction in days of hospital stay (p < 0.05). Budesonide treatment resulted in more symptom-free days (p < 0.05). Both medications were well tolerated and safe. The only demonstrated side effect of ketotifen was weight gain. The growth rate in height for both groups did not differ. CONCLUSION: Both ketotifen and inhaled budesonide are effective, safe, and well-tolerated in the prevention of asthma exacerbation in children particularly in the country with limited resource.

Serum free cortisol index, free cortisol, and total cortisol in critically ill children.

BACKGROUND: In critical illness, serum total cortisol (TC) may not adequately reflect adrenal function because of reduced cortisol-binding globulin (CBG). AIM: To evaluate adrenal function of critically ill children, using free cortisol index (FCI), calculated free cortisol (cFC), and TC levels. METHODS: Thirty-two critically ill and 36 healthy children were included. All children underwent the 1 microg cosyntropin test. TC and CBG levels were measured. Basal and peak TC, FCI, and cFC were determined. RESULTS: Basal and peak TC, FCI, and cFC of critically ill children were significantly higher than those of the controls. Compared with TC, both basal and peak FCI and cFC of the patients were higher than those of controls to a greater degree. Use of FCI or cFC to diagnose adrenal insufficiency (AI) reduced the frequency of diagnosis of AI by 50%. CONCLUSION: FCI and cFC better reflect the dynamic changes of adrenal function of critically ill children.

Measurement of end-expiratory pressure as an indicator of airway patentcy above tracheostomy in children.

The tracheostomy speaking valve is a one-way valve that closes during exhalation. It causes redirection of exhaled gas into the larynx, mouth and nasal cavity, thus enabling children with long-term tracheostomies to speak. Whether a child can tolerate the valve depends mainly on the patency of the upper airway around and above the tracheostomy tube. To measure end-expiratory pressure (EEP) at the tracheostomy tube when the speaking valve is being put in place may be a useful noninvasive tool to assess the patency of the exhalation pathway. The authors, therefore, measured EEP when the patients were first put on the speaking valves and tried to follow-up the patients thereafter. Twenty-two tracheostomized children (aged 3.2 months to 1 7years, male/female 16/6) were recruited for the present study and EEP was measured. It was found that 13 children having the EEP in the range of 2-6 cmH2O could breathe normally through the valves and later could use the valves without any problems, whereas 9 children with EEP in the range of 10-40 cmH2O demonstrated breathing difficulties and the valves had to be taken off immediately. Bronchoscopy revealed upper airway narrowing in all of those children with unsuccessful valve placements. It was concluded that EEP was exceedingly high in children with upper airway narrowing. The measurement of EEP via speaking valves can, thus, be used as an objective indicator to evaluate the patency of upper airway proximal to the tracheostomy tube.

A prospective, randomized double-blind study in children comparing two doses of nebulized L-epinephrine in postintubation croup.

OBJECTIVE: To compare the effectiveness and side effects of nebulized l-epinephrine (NLE) at a dose of 0.05 mL/kg versus 0.5 mL/kg in the treatment of postintubation croup in children. MATERIAL AND METHOD: Thirty-nine children, who developed signs and symptoms of upper airway obstruction (UAO) after extubation, were randomized to receive either 0.05 mL/kg or 0.5 mL/kg of NLE. UAO scores, vital signs (VS) and possible side effects were recorded before and at 20 and 40 minutes after the treatment. RESULTS: Twenty-one and 18 patients were allocated to the 0.05 and 0.5 mL/kg groups, respectively. Both groups showed improvements in UAO scores over time. There were no significant differences in UAO scores and VS between the groups at all time points. Side effects of epinephrine were not observed. CONCLUSION: In children with postintubation croup, the administration of NLE at the dose of 0.05 mL/kg results in similar improvements in the UAO scores, compared with the dose of 0.5 mL/kg. No complications were seen in either dose.

Effect of PM10 pollution in Bangkok on children with and without asthma.

This study aimed to investigate the effects of PM10 concentrations exceeding the Thai national standard (24-hr average, >120 microg/m3) on daily reported respiratory symptoms and peak expiratory flow rate (PEFR) of schoolchildren with and without asthma in Bangkok. The 93 asthmatic and 40 nonasthmatic schoolchildren were randomly recruited from a school located in a highly congested traffic area. Daily respiratory symptoms and PEFR of each child were evaluated and recorded in the diary for 31 successive school days. During the study period, 24-hr average PM10 levels ranged between 46-201 microg/m3. PM10 levels exceeded 120 microg/m3 for 14 days. We found that when PM10 levels were >120 microg/m3, the daily reported nasal irritation of asthmatic children was significantly higher than when PM10 levels were < or =120 microg/m3. In addition, when PM10 levels were >120 microg/m3, nonasthmatic children had a significantly higher daily reported combination of any respiratory symptoms. PEFR did not change with different ambient PM10 levels in both groups. This study suggests that elevated levels of PM10 concentrations in Bangkok affect respiratory symptoms of schoolchildren with and without asthma.