Dexmedetomidine for infant pulmonary function testing

Going the Extra Mile: Why Clinical Research in Cystic Fibrosis Must Include Children

This is an exciting time for research and novel drug development in cystic fibrosis. However, rarely has the adage, “Children are not just little adults” been more relevant. This article is divided into two main sections. In the first, we explore why it is important to involve children in research. We discuss the potential benefits of understanding a disease and its treatment in children, and we highlight that children have the same legal and ethical right to evidence-based therapy as adults. Additionally, we discuss why extrapolation from adults may be inappropriate, for example, medication pharmacokinetics may be different in children, and there may be unpredictable adverse effects. In the second part, we discuss how to involve children and their families in research. We outline the importance and the complexities of selecting appropriate outcome measures, and we discuss the role co-design may have in improving the involvement of children. We highlight the importance of appropriate staffing and resourcing, and we outline some of the common challenges and possible solutions, including practical tips on obtaining consent/assent in children and adolescents. We conclude that it is unethical to simply rely on extrapolation from adult studies because research in young children is challenging and that research should be seen as a normal part of the paediatric therapeutic journey.

The remaining barriers to normalcy in CF: Advances in assessment of CF lung disease

Despite early diagnosis of cystic fibrosis (CF) through newborn screening, a substantial proportion of infants and young children with CF still demonstrate physiologic and structural evidence of lung disease progression, such as obstructive airway disease and bronchiectasis. The growing availability of highly effective CF transmembrane conductance regulatory modulator therapy to the vast majority of people with CF has led to the potential to alter the natural history of CF lung disease, but to assess the full impact of these therapies on CF lung disease and to help guide treatment, sensitive measures of early and mild disease are needed. Chest imaging using computed tomography or magnetic resonance imaging is one approach, but technologic barriers and/or concern about exposure to ionizing radiation may limit its use. However, advances in physiologic measurement techniques and exhaled breath analysis offer another option for assessment of CF lung disease.

The 95% effective dose of intranasal dexmedetomidine sedation for pulmonary function testing in children aged 1-3 years: A biased coin design up-and-down sequential method

STUDY OBJECTIVE

Intranasal dexmedetomidine (DEX) can provide adequate sedation during short examinations in children. However, we found no data regarding the 95% effective dose (ED₉₅) of intranasal DEX for children's pulmonary function testing (PFT).

DESIGN

Prospective study and a biased coin design up-and-down sequential method.

SETTING

Sedation center of Children's Hospital of Chongqing Medical University.

PATIENTS

Children aged 1-3 years undergoing pulmonary function testing.

INTERVENTION

The dose of DEX for each subsequent patient was determined by the response of the previous patient with the biased coin design up-and-down sequential method with an interval of 0.25 μg∙kg^-1.

MEASUREMENTS

Children aged 1-3 years who received pulmonary function testing were involved in this dose-finding trial. Intranasal DEX started at a dose of 2 μg∙kg^-1 on the first patient. The dose of DEX for each subsequent patient was determined by the response of the previous patient with the biased coin design up-and-down sequential method with an interval of 0.25 μg∙kg^-1. The sedation was assessed by the Modified Observer Assessment of Alertness and Sedation (MOAA/S) scale, and recovery was assessed by the modified Aldrete recovery score. The ED₉₅ was calculated using isotonic regression. Other variables, including the sedation onset time, examination time, wake-up time, blood pressure (BP), heart rate (HR), respiratory rate (RR), and oxyhaemoglobin desaturation (SpO₂), were recorded. Adverse events such as hypotension, bradycardia, respiration depression, oxyhaemoglobin desaturation, regurgitation and vomiting were recorded.

MAIN RESULTS

A total of 68 children were enrolled for the study; 62 children had successful sedation, and 6 had failed sedation. The ED₉₅ of intranasal DEX was estimated to be 2.64 μg∙kg^-1 [95% confidence interval (CI), 2.49-2.87 μg∙kg^-1]. The sedation onset time for all patients was 15.0 (12.3-19.0) min. The sedation onset time of successful sedation patients was 15.0 (12.0-19.0) min, the sedation onset time of failed sedation patients was 16.0 (15.0-27.8) min, the examination time was 8 (7-10) min, and the wake-up time was 40 (35-43) min. There were no adverse events during the whole procedure.

CONCLUSION

The ED₉₅ of intranasal DEX sedation in children aged 1-3 years undergoing PFT was 2.64 μg∙kg^-1.

Effects of dexmedetomidine on oxidative stress and inflammatory response in lungs during mechanical ventilation in COPD rats

Effects of dexmedetomidine (Dex) on oxidative stress and inflammatory response in lungs during mechanical ventilation in chronic obstructive pulmonary disease (COPD) rats were investigated. Eleven out of 38 SD rats were randomly selected as the blank control group, and the other 27 rats were subjected to modeling. After the modeling, 11 rats in the blank control group and 11 rats randomly selected from the model group received non-invasive test for lung function. Three rats from the blank control group and 3 rats from the model group were selected for hematoxylin and eosin (HE) staining to confirm successful modeling, and the other 24 rats were randomly divided into 3 groups, 8 rats in each group, including model control, Dex low-dose and Dex high-dose group. A COPD rat model was established by passive cigarette smoking and intratracheal instillation of lipopolysaccharide. Each group underwent mechanical ventilation for 2 h. The Dex low-dose group and Dex high-dose group were intravenously administered at 1.0 µg/kg/h and 5.0 µg/kg/h of Dex, and the other two groups received intravenous drip of the same amount of normal saline. Blood gas analysis was performed to calculate carbon dioxide partial pressure (PaCO₂), oxygen partial pressure (PaO₂) and blood pH. HE staining was performed to analyze pulmonary pathological features of COPD rat model. Serum inflammatory factors interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA) were detected by ELISA, and the levels of antioxidant enzymes superoxide dismutase 2 (SOD2) and catalase were analyzed by western blot analysis. After 28 days of modeling, TV, PEF, FEV0.3 and FEV0.3/FVC decreased significantly in the COPD model group. HE staining showed that in the model group, the alveolar cells became larger, the alveolar wall became thinner, and some alveolar walls were even broken. The lung lobule showed obvious cell degeneration, necrosis and shedding, and the interstitial inflammatory cell infiltration, suggesting that the COPD rat model was successfully established. After 2 h of mechanical ventilation and Dex intravenous infusion, PaCO₂ decreased, PaO₂ increased, and blood pH value increased (p<0.05). Inflammatory factors IL-8 and TNF-α decreased (p<0.05). Oxidative stress index MDA also decreased (p<0.05), antioxidant enzymes SOD2 and catalase increased (p<0.05). Dexmedetomidine can improve the oxidative stress response during mechanical ventilation in rats with COPD, and can reduce the inflammation of lung tissue, thus protecting the lung tissue of COPD rats.

Elevated lung clearance index in infants with cystic fibrosis shortly after birth

It is not known at what age lung function impairment may arise in children with cystic fibrosis (CF). We assessed lung function shortly after birth in infants with CF diagnosed by newborn screening.We performed infant lung function measurements in a prospective cohort of infants with CF and healthy controls. We assessed lung clearance index (LCI), functional residual capacity (FRC) and tidal breathing parameters. The primary outcome was prevalence and severity of abnormal lung function (±1.64 z-scores) in CF.We enrolled 53 infants with CF (mean age 7.8 weeks) and 57 controls (mean age 5.2 weeks). Compared to controls, LCI and FRC were elevated (mean difference 0.30, 95% CI 0.02-0.60; p=0.034 and 14.5 mL, 95% CI 7.7-21.3 mL; p<0.001, respectively), while ratio of time to peak tidal expiratory flow to expiratory time was decreased in infants with CF. In 22 (41.5%) infants with CF, either LCI or FRC exceeded 1.64 z-scores; three infants had both elevated LCI and FRC.Shortly after birth, abnormal lung function is prevalent in CF infants. Ventilation inhomogeneity or hyperinflation may serve as noninvasive markers to monitor CF lung disease and specific treatment effects, and could thus be used as outcome parameters for future intervention studies in this age group.

Efficacy and safety of chloral hydrate sedation in infants for pulmonary function tests

Objective:

To describe the efficacy and safety of chloral hydrate sedation in infants for pulmonary function tests.

Methods:

All sedation attempts for pulmonary function tests in infants carried out between June 2007 and August 2014 were evaluated. Obstructive sleep apnea and heart disease were contraindications to the exams. Anthropometric data, exam indication, used dose, outcomes of sedation and clinical events were recorded and described.

Results:

The sedation attempts in 277 infants (165 boys) with a median age of 51.5 weeks of life (14-182 weeks) were evaluated. The main indication for the tests was recurrent wheezing (56%) and the chloral hydrate dose ranged from 50 to 80mg/kg (orally). Eighteen (6.5%) infants had some type of clinical complication, with the most frequent being cough and/or airway secretion (1.8%); respiratory distress (1.4%) and vomiting (1.1%). A preterm infant had bradycardia for approximately 15 minutes, which was responsive to tactile stimulation. All observed adverse effects were transient and there was no need for resuscitation or use of injectable medications.

Conclusions:

The data demonstrated that chloral hydrate at the employed doses is a safe and effective medicament for sedation during short procedures in infants, such as pulmonary function tests. Because of the possibility of severe adverse events, recommendations on doses and contraindications should be strictly followed and infants should be monitored by trained staff.

Efficacy and safety of chloral hydrate sedation in infants for pulmonary function tests

OBJECTIVE

To describe the efficacy and safety of chloral hydrate sedation in infants for pulmonary function tests.

METHODS

All sedation attempts for pulmonary function tests in infants carried out between June 2007 and August 2014 were evaluated. Obstructive sleep apnea and heart disease were contraindications to the exams. Anthropometric data, exam indication, used dose, outcomes of sedation and clinical events were recorded and described.

RESULTS

The sedation attempts in 277 infants (165 boys) with a median age of 51.5 weeks of life (14 to 182 weeks) were evaluated. The main indication for the tests was recurrent wheezing (56%) and the chloral hydrate dose ranged from 50 to 80mg/kg (orally). Eighteen (6.5%) infants had some type of clinical complication, with the most frequent being cough and/or airway secretion (1.8%); respiratory distress (1.4%) and vomiting (1.1%). A preterm infant had bradycardia for approximately 15 minutes, which was responsive to tactile stimulation. All observed adverse effects were transient and there was no need for resuscitation or use of injectable medications.

CONCLUSIONS

The data demonstrated that chloral hydrate at the employed doses is a safe and effective medicament for sedation during short procedures in infants, such as pulmonary function tests. Because of the possibility of severe adverse events, recommendations on doses and contraindications should be strictly followed and infants should be monitored by trained staff.

Pediatric Pulmonology year in review 2015: Part 4

In this article, we highlight cystic fibrosis (CF) research published in Pediatric Pulmonology during 2015. Articles from other journals that reflect similar themes, and those of special importance, are also included. Pediatr Pulmonol. 2016;51:754-765. © 2016 Wiley Periodicals, Inc.