Computerized Dead-Space Volume Measurement of Face Masks Applied to Simulated Faces.

BACKGROUND: The dead-space volume (VD) of face masks for metered-dose inhaler treatments is particularly important in infants and young children with asthma, who have relatively low tidal volumes. Data about VD have been traditionally obtained from water displacement measurements, in which masks are held against a flat surface. Because, in real life, masks are placed against the face, VD is likely to differ considerably between masks depending upon their contour and fit. The aim of this study was to develop an accurate and reliable way to measure VD electronically and to apply this technique by comparing the electronic VD of commonly available face masks. METHODS: Average digital faces were obtained from 3-dimensional images of 270 infants and children. Commonly used face masks (small and medium) from various manufacturers (Monaghan Medical, Pari Respiratory Equipment, Philips Respironics, and InspiRx) were scanned and digitized by means of computed tomography. Each mask was electronically applied to its respective digital face, and the VD enclosed (mL) was computerized and precisely measured. RESULTS: VD varied between 22.6 mL (SootherMask, InspiRx) and 43.1 mL (Vortex, Pari) for small masks and between 41.7 mL (SootherMask) and 71.5 mL (AeroChamber, Monaghan Medical) for medium masks. These values were significantly lower and less variable than measurements obtained by water displacement. CONCLUSIONS: Computerized techniques provide an innovative and relatively simple way of accurately measuring the VD of face masks applied to digital faces. As determined by computerized measurement using average-size virtual faces, the InspiRx masks had a significantly smaller VD for both small and medium masks compared with the other masks. This is of considerable importance with respect to aerosol dose and delivery time, particularly in young children. (ClinicalTrials.gov registration NCT01274299.).

Design of aerosol face masks for children using computerized 3D face analysis.

BACKGROUND: Aerosol masks were originally developed for adults and downsized for children. Overall fit to minimize dead space and a tight seal are problematic, because children's faces undergo rapid and marked topographic and internal anthropometric changes in their first few months/years of life. Facial three-dimensional (3D) anthropometric data were used to design an optimized pediatric mask. METHODS: Children's faces (n=271, aged 1 month to 4 years) were scanned with 3D technology. Data for the distance from the bridge of the nose to the tip of the chin (H) and the width of the mouth opening (W) were used to categorize the scans into "small," "medium," and "large" "clusters." RESULTS: "Average" masks were developed from each cluster to provide an optimal seal with minimal dead space. The resulting computerized contour, W and H, were used to develop the SootherMask® that enables children, "suckling" on their own pacifier, to keep the mask on their face, mainly by means of subatmospheric pressure. The relatively wide and flexible rim of the mask accommodates variations in facial size within and between clusters. CONCLUSIONS: Unique pediatric face masks were developed based on anthropometric data obtained through computerized 3D face analysis. These masks follow facial contours and gently seal to the child's face, and thus may minimize aerosol leakage and dead space.

A double-blind, placebo-controlled, randomized trial of montelukast for acute bronchiolitis.

BACKGROUND: Cysteinyl leukotrienes are implicated in the inflammation of bronchiolitis. Recently, a specific cysteinyl leukotriene receptor antagonist, montelukast (Singulair [MSD, Haarlem, Netherlands]), has been approved for infants in granule sachets. OBJECTIVE: Our goal was to evaluate the effect of montelukast on clinical progress and on cytokines in acute bronchiolitis. METHODS: This was a randomized, placebo-controlled, double-blind, parallel-group study in 2 medical centers. Fifty-three infants (mean age: 3.8+/-3.5 months) with a first episode of acute bronchiolitis were randomly assigned to receive either 4-mg montelukast sachets or placebo, every day, from hospital admission until discharge. The primary outcome was length of stay, and secondary outcomes included clinical severity score (maximum of 12) and changes in type 1 and 2 cytokine levels (including interleukin4/IFN-gamma ratio as a surrogate for the T-helper 2/T-helper 1 ratio) in nasal lavage. RESULTS: Both groups were comparable at baseline, and cytokine levels correlated positively with disease severity. There were neither differences in length of stay (4.63+/-1.88 [placebo group] vs 4.65+/-1.97 days [montelukast group]) nor in clinical severity score and cytokine levels between the 2 groups. No differences in interleukin 4/IFN-gamma ratio between the 2 groups were seen. There was a slight tendency for infants in the montelukast group to recover more slowly than those in the placebo group (clinical severity score at discharge: 6.1+/-2.4 vs 4.8+/-2.2, respectively). CONCLUSIONS: Montelukast did not improve the clinical course in acute bronchiolitis. No significant effect of montelukast on the T-helper 2/T-helper 1 cytokine ratio when given in the early acute phase could be demonstrated.

Formoterol turbuhaler is as effective as salbutamol diskus in relieving adenosine-induced bronchoconstriction in children.

Salbutamol diskus (SD) and formoterol turbuhaler (FT) are both fast-acting beta(2) agonists delivery systems used to relieve bronchoconstriction, such as that which accompanies acute exacerbations of asthma. Although SD (which is used only on an as-needed basis) is flow independent, the FT (currently recommended for regular therapy) requires a forceful deep inspiration. Thus, the efficacy of FT in children with bronchoconstriction may be inferior to that of SD. We have studied the bronchodilatation response induced by FT after a standard adenosine-5-monophosphate (AMP) bronchial challenge, and compared it to that induced by SD, and placebo. Seventeen children (mean age +/- SD 10.3 +/- 1.7 y) with asthma underwent three AMP challenges, each time followed by inhalation of either placebo, SD (200 mug) or FT (9 mug), in random order. Patterns of bronchodilatation (forced expiratory volume in 1 second recovery) to 90% of baseline levels were compared. Both SD and FT were significantly better than placebo. FT was slightly better than SD, but this difference was not statistically significant. FT and SD are both effective bronchodilators and may be of comparable efficiency during acute bronchoconstriction in young children with asthma.

LDL oxidation is associated with increased blood hemoglobin A1c levels in diabetic patients.

AIM: To investigate whether levels of blood HbA1c in diabetic patients are associated with susceptibility of LDL to oxidation. METHODS: LDL was separated from blood of 40 diabetic patients with known blood glucose and HbA1c levels. The tendency to undergo lipid peroxidation was assessed via lag time required for initiation of LDL oxidation. HbA1c formation was measured in vitro following incubation of red blood cell (RBC) hemolysate for 3 months with increasing concentrations of glucose in the absence or presence of LDL or oxidized LDL. RESULTS: Lag time for copper-induced LDL oxidation was twice as long in normal subjects compared to diabetic patients. Correlation analyses between LDL oxidation lag time and HbA1c blood levels revealed an R value of 0.74. Incubation of RBC hemolysate with high glucose concentration (up to 400 mg/dl) resulted in increased blood HbA1c concentration by up to 107%. Addition of LDL to this hemolysate over a period of 3 months resulted in LDL oxidation and an increase in HbA1c levels by up to 168%. Similarly, addition of oxidized LDL to the hemolysate increased HbA1c by up to 240%. CONCLUSIONS: Increased tendency of LDL to undergo lipid peroxidation in diabetic patients contributes to increased levels of blood HbA1c, mainly in those with HbA1c<7.3.

Beta-agonist aerosol distribution in respiratory syncytial virus bronchiolitis in infants.

UNLABELLED: Bronchodilator aerosols are frequently administered to infants with bronchiolitis but with little success. The efficacy of aerosol treatments depends mainly on adequate targeting of the aerosol particles to the inflamed airways. This study evaluated the lower respiratory tract distribution characteristics of nebulized bronchodilators in infants with acute bronchiolitis. METHODS: Twelve infants (mean age +/- SD, 8 mo +/- 4 mo) who were admitted for acute respiratory syncytial virus bronchiolitis were treated with (99m)Tc-albuterol aerosol. Gamma-scintigraphy was used to assess total body and lung deposition as well as pulmonary distribution of the medication. RESULTS: Of the total 6-min nebulized dose (i.e., drug aerosol dose leaving the nebulizer [not the nebulizer charge]), 1.5% +/- 0.7% reached the right lung, with only approximately one third of that (0.6%) penetrating to the peripheral lung zone. There was 7.8% +/- 4.9% deposition in the upper respiratory and gastrointestinal tracts and 10%-12% remained on the face. No correlation was found between any of the deposition indices and the clinical response data or any of the demographic parameters (e.g., height, weight, body surface area, or clinical score). CONCLUSION: Poor total aerosol deposition in infants may be related as much to their small conducting airways as to the disease state. There is considerable room for improvement in aerosol delivery in this age group, with greater emphasis on targeting narrowed peripheral airways with superfine aerosols.