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ABSTRACT: Abstract Background: Aerosol therapy in preterm infants is challenging, as a very small proportion of the drug deposits in the lungs. Aim: Our aim was to compare efficiency of standard devices with newer, more efficient aerosol delivery devices. Methods: Using salbutamol as a drug marker, we studied two prototypes of the investigational eFlow(®) nebulizer for babies (PARI Pharma GmbH), a jet nebulizer (Intersurgical(®) Cirrus(®)), and a pressurized metered dose inhaler (pMDI; GSK) with a detergent-coated holding chamber (AeroChamber(®) MV) in the premature infant nose throat-model (PrINT-model) of a 32-week preterm infant (1,750 g). A filter or an impactor was placed below the infant model's "trachea" to capture the drug dose or particle size, respectively, that would have been deposited in the lung. Results: Lung dose (percentage of nominal dose) was 1.5%, 6.8%, and 18.0-20.6% for the jet nebulizer, pMDI-holding chamber, and investigational eFlow nebulizers, respectively (p<0.001). Jet nebulizer residue was 69.4% and 10.7-13.9% for the investigational eFlow nebulizers (p<0.001). Adding an elbow extension between the eFlow and the model significantly lowered lung dose (p<0.001). A breathing pattern with lower tidal volume decreased deposition in the PrINT-model and device residue (p<0.05), but did not decrease lung dose. Conclusions: In a model for infant aerosol inhalation, we confirmed low lung dose using jet nebulizers and pMDI-holding chambers, whereas newer, more specialized vibrating membrane devices, designed specifically for use in preterm infants, deliver up to 20 times more drug to the infant's lung.
Journal of Aerosol Medicine and Pulmonary Drug Delivery 12/2012; · 2.20 Impact Factor
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ABSTRACT: BACKGROUND: Adherence to prescribed inhaled medication is often low in young children. Poor adherence to medication may contribute to lack of symptom control. Doctors are not good at predicting the adherence rates of their patients, and parental report of adherence does not correlate with objective measures of adherence. The objective of this study was to investigate whether parental admission of non-adherence and reasons given for non-adherence correlated with objectively measured adherence. METHODS: Adherence to prescribed inhaled corticosteroid treatment was monitored electronically in 132 children aged 2-6 years who were participating in a randomised controlled trial comparing different inhaler devices. Follow-up was carried out every 3 months for a year. Parental answers to simple questions about adherence were compared to electronically measured adherence. RESULTS: Mean adherence ranged from zero to 100%. Intra-participant adherence varied throughout the year-long study period (mean variance for individual children between quarterly periods was 28.5%). Parents who reported missed doses, generally missed at least half of the prescribed doses. Parents who reported that not a single prescribed dose was missed, still missed 20% of doses on average. Adherence was particularly low when parents cited initiating their own trial off medication as a reason for missing doses. CONCLUSIONS: By examining parental response to questions enquiring whether any doses were missed, healthcare providers can gain a modest degree of insight into their patients' true adherence to prescribed medication. Adherence to prescribed asthma medication is extremely variable in young children. TRIAL REGISTRATION NUMBER: Data from this study were derived from a randomised controlled trial (ACTRN12608000294358).
Archives of Disease in Childhood 10/2012; · 2.88 Impact Factor
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ABSTRACT: To investigate the influence of an incentive device, the Funhaler, on spacer technique and symptom control in young children with asthma and recurrent wheeze.
Randomised controlled trial where 132 2-6 year old asthmatic children received regular inhaled fluticasone through Aerochamber Plus, or Funhaler. The setting was a research clinic at Princess Margaret Hospital for Children, Perth, Australia. Subjects were followed up for a year. The main outcome measure was asthma symptoms. Proficiency in spacer technique was measured as salbutamol inhaled from spacer onto filter. Quality of life was measured every three months. Groups were compared in terms of spacer technique, symptoms and quality of life. The relationship between spacer technique and clinical outcome was examined.
There was no difference between Funhaler and Aerochamber groups in wheeze free days, cough free days, bronchodilator free days or quality of life (P = 0.90, 0.87, 0.74 and 0.11 respectively). Spacer technique was better in the Funhaler group (P = 0.05), particularly in subjects younger than 4 years of age (P = 0.002). Drug dose on filter (as the mean of five 100 mg doses) ranged from zero to 136 mg.
Use of Funhaler incentive device does not improve clinical outcome, but improves spacer technique in children younger than 4 years. Variability in drug delivery is large in young children using pressurised metered dose inhalers and spacers.
Journal of Paediatrics and Child Health 01/2012; 48(1):52-6. · 1.28 Impact Factor
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ABSTRACT: Purchase and disinfection costs together with medication delivery factors may influence the choice of drug delivery options. This study assessed salbutamol delivery habits used in respiratory laboratories and quantified the delivered salbutamol dose of locally available spacers.
An online survey was used to obtain data on disinfection processes, costs and delivery device choices. The delivered dose of six commercial spacers was assessed. Particle size distribution of salbutamol (Ventolin, GSK, 100µg/actuation) from six spacers of each type was measured by quantifying the amount of drug (µg) deposited on each stage of an Anderson Cascade Impactor (ACI) using UV spectrophotometry. Clinical conditions were simulated using a flow volume simulator (FVS) and delivery of salbutamol via a pressurized metered dose inhaler and spacer to a low-resistance filter was measured.
Fifty survey responses were obtained, with 37 (74%) using ≥1 type of spacer of which 92% processed single use spacers. The most commonly used spacers were Volumatic (n=24), Breath-a-tech (n=8) and Space Chamber (n=7). The median disinfection cost was $2.45. Delivered salbutamol dose varied significantly and ranged from 16.98 to 38.28 µg with the ACI and 22.56 to 58.82 µg with the FVS. Using the FVS, small-volume spacers delivered similar doses (22.56 to 28.46 µg), while large-volume spacers delivery was more varied (24.31 to 58.82 µg).
The majority of respiratory laboratories had not updated re-processing policies to comply with new regulations. The delivered salbutamol dose varied significantly and this might effect the choice of preferred spacer type.
Respirology 01/2011; 16(4):639-44. · 2.42 Impact Factor
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ABSTRACT: The goal was to determine the number of breaths required to inhale salbutamol from different spacers/valved holding chambers (VHCs).
Breathing patterns were recorded for 2- to 7-year-old children inhaling placebo from 4 different spacers/VHCs and were simulated by a flow generator. Drug delivery with different numbers of tidal breaths and with a single maximal breath was compared.
With tidal breathing, mean inhalation volumes were large, ranging from 384 mL to 445 mL. Mean values for drug delivery with an Aerochamber Plus (Trudell, London, Canada) were 40% (95% confidence interval [CI]: 34%-46%) and 41% (95% CI: 36%-47%) of the total dose with 2 and 9 tidal breaths, respectively. Mean drug delivery values with these breath numbers with a Funhaler (Visiomed, Perth, Australia) were 39% (95% CI: 34%-43%) and 38% (95% CI: 35%-42%), respectively. With a Volumatic (GlaxoSmithKline, Melbourne, Australia), mean drug delivery values with 2 and 9 tidal breaths were 37% (95% CI: 33%-41%) and 43% (95% CI: 40%-46%), respectively (P = .02); there was no significant difference in drug delivery with 3 versus 9 tidal breaths. With the modified soft drink bottle, drug delivery. Drug delivery was not improved with a single maximal breath with any device.
For young children, tidal breaths through a spacer/VHC were much larger than expected. Two tidal breaths were adequate for small-volume VHCs and a 500-mL modified soft drink bottle, and 3 tidal breaths were adequate for the larger Volumatic VHC.
PEDIATRICS 11/2010; 126(6):e1493-8. · 4.47 Impact Factor
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ABSTRACT: The glutathione S-transferase enzymes (GSTs) play an important role in the detoxification of environmental tobacco smoke (ETS), which contributes to airway inflammation, a key component of asthma. Genetic variation in GST genes may influence individuals' ability to detoxify environmental pollutants.
To examine the role of polymorphisms in GSTP1 (Ile105Val and Ala114Val), alone and in combination with ETS exposure, on atopy and asthma severity.
GSTP1 Ile105Val and Ala114Val were genotyped and ETS exposure was assessed by parental questionnaire, which was validated by urinary cotinine measurements. Associations between ETS exposure, GSTP1 polymorphisms, and their interaction on atopy and asthma severity were investigated.
For the functional GSTP1 105 SNP, those with the Ile/Ile genotype had odds for atopy of 2.77 (p = .054) when assessed by genotype alone, which increased to 9.02 (p = .050) when ETS was included, relative to individuals with other genotypes. Likewise, compared to children with other GSTP1 114 genotypes, those with Ala/Ala genotype had a 5.47-fold (p = .002) increased risk of atopy (p = .020) when assessed by genotype alone, increasing to 9.17-fold when ETS was included. The 105 Ile/Ile individuals all had the AA (105 Ile/Ile and 114 Ala/Ala) haplotype group; therefore, the odds for atopy were the same. Individuals without any *C haplotype (105 Val and 114 Val allele) who were exposed to ETS had a 9.17-fold increased risk of atopy when compared with individuals with at least one *C haplotype and not exposed to ETS (p = .020).
There were significant interactions between GSTP1 SNPs, atopy, and ETS exposure in this cohort.
Journal of Asthma 11/2010; 47(9):1049-56. · 1.52 Impact Factor
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ABSTRACT: Output from spacers (or valved holding chambers) is sensitive to changes in breathing pattern. Different spacers have unique characteristics that may influence breathing. A method used for breathing simulation, where the simulated breathing can be recorded on subjects while they are using spacers, may allow for more accurate in vitro estimation of drug delivery in specific populations, using specific spacers.
A flow chamber was used to record breathing while salbutamol was administered to two adult subjects through different spacers. Each subject performed a series of breathing patterns over a range of different inhalation volumes and flows. Salbutamol "inhaled" by subjects was captured on inspiratory filters and quantified by ultraviolet spectrophotometry. Recorded breathing patterns were simulated and ex vivo drug delivery was compared to in vitro drug delivery. Three equipment configurations were used to validate different aspects of the methodology. Configuration 1: breathing recorded by pneumotachometer placed directly between a human subject and the spacer. Breathing simulation performed with an identical setup. Configuration 2: spacer enclosed within a flow-chamber while breathing was recorded. Breathing simulation performed with an identical setup. Configuration 3: spacer enclosed in flow chamber to record breathing, but not when simulating breathing. In each configuration, the ex vivo and in vitro (simulated) filter doses were compared.
Configuration 1: the median difference between ex vivo and in vitro filter doses was 0.4% (range: -12.2 to 6.9%). Configuration 2: the median difference was -2.3% (range: -9.0 to 5.0%). Configuration 3: the median difference was 1.7% (range: -11.5 to 3.9%).
Our results indicate that in vitro simulated drug delivery using this method of recording using a flow chamber, closely approximates ex vivo total drug delivery. This technique allows for recording of breathing on patients while they are using spacers, with minimum increase in dead space or resistance, and no physical alteration in the patient-device interface.
Journal of Aerosol Medicine and Pulmonary Drug Delivery 05/2010; 23(5):311-22. · 2.20 Impact Factor
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ABSTRACT: This study investigates the impact of measuring adherence and providing feedback on medication usage by children with unstable asthma. Adherence was measured using an electronic monitoring device. Subjects were randomized to either being told of their adherence during review consultations or for their adherence to remain undisclosed to their parents and treating physician. Subjects were reviewed monthly for 4 months. Twenty-six children aged between 6 and 14 years were recruited. Adherence was significantly higher in the intervention group (79% versus 58%, p <.01). There were significant improvements in clinical measures of disease control compared with baseline in both groups. The change in forced expiratory volume in 1 s (FEV(1)) (% predicted) was greater in those subjects receiving feedback (13.8% versus 9.8%). However, lung function values were lower in the intervention group at baseline and the relative improvement failed to reach statistical significance. Measuring adherence and providing feedback increases the use of preventive medication. A larger study is required to explore implications for disease control.
Journal of Asthma 03/2010; 47(2):198-201. · 1.52 Impact Factor
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ABSTRACT: Xenobiotics in the maternal circulation are capable of crossing the placental barrier so a reduction in the mother and fetus's detoxification ability due to genetic variation in the glutathione S-transferases (GSTs) could expose the fetus to higher levels of toxins.
To investigate the interactive effects of maternal smoking during pregnancy with maternal and infant GST genotypes on airway responsiveness (AR) and lung function in infancy.
GSTT1, GSTP1 and GSTM1 were genotyped in infants and mothers, in utero smoke exposure was evaluated by questionnaire, AR was assessed by histamine challenge and Vmax(FRC) was measured using the rapid thoracoabdominal compression technique. We investigated the interactive effects of maternal smoking during pregnancy with maternal and infant GST genes on AR and lung function at 1, 6, and 12 months and longitudinally throughout the first year.
Infant and/or maternal GSTT1 nonnull was associated with reduced AR at 12 months and throughout the first year and increased Vmax(FRC) at 6 months. Maternal GSTP1 Val/Val or Ile/Val was associated with increased Vmax(FRC) at 6 months. In infants exposed to in utero smoke, infant and/or maternal GSTT1 nonnull was associated with reduced AR at 1 month and throughout the first year and increased Vmax(FRC) throughout the first year. Maternal GSTP1 Val/Val or Ile/Val was associated with increased Vmax(FRC) at 6 months.
GST genes may be especially important during fetal development as they may modify, through proficient detoxification, the effects of in utero maternal smoke exposure on AR and lung function in infants.
American Journal of Respiratory and Critical Care Medicine 10/2009; 181(1):64-71. · 11.08 Impact Factor
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ABSTRACT: Lung deposition of inhaled steroids, likely to be of benefit in the anti-inflammatory treatment of asthma in young children, is low. This is explained by age specific anatomical and physiological characteristics as well as poor cooperation with aerosol therapy. However, total lung deposition and the ratio of lung deposition to oropharyngeal deposition are key determinants of clinical efficacy and of systemic side effects of aerosolized drugs.
The aim of this study was to determine lung deposition and ratio of lung deposition to oropharyngeal deposition using a modified vibrating membrane nebuliser to deliver budesonide with a small particle size, taking into account the needs of young children.
Ten asthmatic children (5 males), mean age 20.3 months (range 6-41 months) inhaled radiolabelled budesonide (MMD 2.6microm) through a modified vibrating membrane nebuliser (modified PARI e-Flow). Lung deposition expressed as a percentage of the emitted dose was measured using scintigraphy and the ratio of lung deposition to oropharyngeal deposition was calculated.
Mean lung deposition (SD) expressed as percentage of emitted dose and mean lung to oropharyngeal deposition ratio (SD) in quietly breathing children (n=5) and in children crying during inhalation were 48.6% (10.5) versus 20.0% (10.9), and 1.0 (0.3) versus 0.3 (0.2), respectively.
We have shown that by using an improved age-adjusted complementary combination of delivery device and drug formulation to deliver small particles, lung deposition and ratio of lung deposition to oropharyngeal deposition in young asthmatic children is highly improved. But the main factor limiting aerosol delivery in this age group remains cooperation.
Respiratory medicine 07/2009; 103(11):1738-45. · 2.33 Impact Factor
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ABSTRACT: Adherence with preventive asthma medication by young children is an important factor when evaluating a suboptimal response to treatment. However, few data exist regarding the accuracy of subjective measures of adherence and factors associated with adherence in young children.
Fifty-one asthmatic children aged 18 months to 7 years had their use of preventive asthma medication monitored using an electronic monitoring device (Smartinhaler) for 1 month. At a follow-up visit the child's parent was asked how often medication had been given and they also completed a confidential questionnaire that included questions about medication usage, barriers to optimal adherence and parenting. The treating physician made an estimate of the child's likely use of medication.
The median use of medication as determined by the Smartinhaler was 70.5% (range 21.4-100%). The parents' verbal reports (85.1%) and questionnaire responses (84.2%) overestimated medication usage. The physician was not able to determine which parents correctly estimated their child's use of medication (P = 0.28). The child's age, level of parental education and annual family income did not influence adherence. Parents reported simply 'forgetting' or their child's 'reaction to being given medication' as the principal barriers to adherence. There was a significant association between how stressful the parent found parenting and adherence (P = 0.05).
Adherence with preventive medication, even within the context of a research study, was generally low and highly variable. Subjective measures of adherence were found to overestimate adherence in young asthmatics.
Respirology 07/2008; 13(4):559-63. · 2.42 Impact Factor
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ABSTRACT: Cigarette smoke is a major source of free radicals and oxidative stress. With a significant proportion of women still smoking during pregnancy, this common and avoidable exposure has the potential to influence infant oxidative status, which is implicated in the increased propensity for airway inflammation and asthma. The aim of this study was to examine the effects of maternal smoking on markers of infant oxidative stress.
The level of oxidative stress (using urinary F2-isoprostanes as a marker of lipid peroxidation) was compared in infants of smokers (n = 33) and non-smokers (n = 54) at 3 months of age. These groups were balanced for maternal atopy and socioeconomic status. Infant urinary cotinine levels were also measured as an indicator of early postnatal cigarette smoke exposure.
Maternal smoking was associated with significantly higher infant cotinine levels, despite the fact that most smoking mothers (83.8%) claimed not to smoke near their baby. Maternal smoking was associated with significantly higher markers of oxidative stress (F2-isoprostane) at 3 months of age. There was also a positive correlation between urinary F2-isoprostanes and infant urinary cotinine levels.
Although this study does not separate the prenatal and postnatal effects of smoking, these findings indicate that environmental tobacco smoke in the early postnatal period adversely affects pro-oxidative/antioxidative status within weeks of life in very early infancy.
Thorax 09/2007; 62(8):714-7. · 6.84 Impact Factor
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ABSTRACT: With the dramatic rise in asthma and respiratory disease, there is an urgent need to determine the effects of common environmental exposures on early immune development. In this study, we examined the effects of maternal smoking as a major adverse exposure in early life, on mucosal immune function and allergen sensitization in the first year of life. A cohort of 60 smokers and 62 non-smokers was recruited in pregnancy, and followed prospectively at 3 and 12 months of age for saliva collection [for immunoglobulin (Ig) A measurements], urine collection (for cotinine levels) and clinical assessments (for allergy and infection history). Allergen skin-prick tests were also performed at 12 months of age. Specific IgA to common colonizing bacteria was measured on saliva samples, including pneumococcal polysaccharide (PS) serotype 14 and non-typeable Haemophilus influenza (NTHI) outer membrane protein 6 (OMP6). Eighty-two mothers and their infants completed the 12-month follow-up period--56 in the maternal non-smoking group and 26 in the maternal smoking group. Maternal smoking was associated with significantly higher total infant salivary IgA at 12 months of age (p = 0.026), and more chronic upper respiratory tract symptoms (p = 0.012). However, there were no differences in the level of specific IgA antibodies to common colonizing bacteria (pneumococcal PS serotype 14 and NTHI OMP6). In general, the IgA levels at 12 months were higher in children who had more chest infections in the first year (Kendall's tau b, 0.282; p = 0.003). There was also a trend of lower respiratory tract symptoms (wheeze) (p = 0.142) in infants of smokers. There were no effects of maternal smoking on the rates of allergen sensitization, atopic dermatitis and food allergy at 12 months of age. In conclusion, maternal smoking did not inhibit the production of anti-microbial IgA, suggesting that other factors are responsible for the increased susceptibility to infection in these infants. The increased mucosal inflammation in these children was not associated with effects on early allergy propensity.
Pediatric Allergy and Immunology 04/2007; 18(2):118-27. · 2.46 Impact Factor
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ABSTRACT: It has been shown in vitro that even a small air leak in the facemask can drastically reduce the efficiency of drug delivery. In addition, it has been shown that drug deposition on the face does significantly add to overall drug loss and has the potential of local side effects. The aim of this study is therefore to verify these findings in vivo. Eight asymptomatic recurrently wheezy children, aged 18-36 months, inhaled a radiolabeled salbutamol formulation either from a pressurized metered-dose inhaler through a spacer with attached facemask or from a nebulizer with attached facemask. Drug deposition of radiolabeled salbutamol was assessed with a gamma camera and expressed as a percentage of the total dose. Lung deposition expressed as a percentage of the total dose (metered dose and nebulizer fill, respectively) was 0.2% and 0.3% in children who inhaled with a non-tightly fitted facemask. Lung deposition was 0.6% and 1.4% in screaming children with a tightly fitted facemask and between 4.8% and 8.2% in patients breathing normally. Overall mask deposition was between 0.8% and 5.2%. Overall face deposition was between 2.6% and 8.4%. The results from this pilot study support the results found in in vitro studies, where a facemask leak greatly reduces drug delivery to the patient.
Journal of Aerosol Medicine 02/2007; 20 Suppl 1:S78-83; discussion S83-4. · 1.61 Impact Factor
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ABSTRACT: Monitoring devices attached to pressurised metered dose inhalers provide an important objective measurement of patient adherence with asthma medications in clinical and research settings. The Smart-inhaler is a relatively new device that has not been previously validated. This study examines the accuracy of the Smart-inhaler in a bench-top experiment and compares it with a previously validated device, the Doser. Ten Smart-inhalers and five Dosers were actuated twice on two occasions per day for 30 days (120 doses). Six Smart-inhalers were also actuated 30 times in rapid succession to examine the ability of the Smart-inhaler to detect "dumping". Five Smart-inhalers failed to detect the first one or two doses. However, when the aerosol canister was placed more firmly in the device, actuating the device in the process, the following two doses were recorded accurately in all ten devices. Otherwise all ten Smart-inhalers and five Dosers recorded all actuations faithfully and there were no spurious recordings. The six Smart-inhalers recorded all 30 doses delivered in rapid succession. The Smart-inhaler and Doser are both highly accurate at measuring actuated doses and no spurious doses were recorded in an in vitro setting.
Respiratory Medicine 06/2006; 100(5):841-5. · 2.47 Impact Factor
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Sunalene G Devadason
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ABSTRACT: Inhalational drug delivery is the primary mode of asthma therapy in children and is the main focus of this article. Pressurized metered dose inhalers (pMDIs) are now the method of choice in infants and children under 5 years old, when used in combination with an appropriate valved holding chamber or spacer. Spacers are particularly important for steroid inhalation to maximize lung deposition and minimize unwanted oropharyngeal deposition. Optimal inhalation technique with a pMDI-spacer in infants is to inhale the drug by breathing tidally through the spacer. Drug delivery to the lungs using pMDIs can vary greatly, depending on the formulation used and the age of the child. Dry powder inhalers (DPIs) are driven by the peak inspiratory flow of the patient and are usually not appropriate for children under 5 or 6 years of age. Nebulizers continue to play a role in the treatment of acute asthma where high doses of bronchodilator are required, though multiple doses via pMDI spacer may suffice. Important drug delivery issues specific to children include compliance, use of mask versus mouthpiece, lower tidal volumes and inspiratory flows, determination of appropriate dosages, and minimization of adverse local and systemic effects.
Journal of Aerosol Medicine 02/2006; 19(1):61-6. · 1.61 Impact Factor
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ABSTRACT: The purpose of the study was to label Flixotide (fluticasone propionate [FP] with HFA propellant), with technetium-99m and validate that (99m)Tc acts as a suitable marker for FP when delivered via pMDI-spacer. Sodium pertechnetate was mixed with 5 mL of butanone. (99m)Tc was extracted into butanone and transferred into an empty canister. The (99m)Tc lined canister was heated, and the butanone evaporated to dryness. A supercooled commercial Flixotide canister was decrimped, and the contents transferred to the (99m)Tc lined canister and recrimped. The particle size distribution of FP and (99m)Tc from 10 radiolabeled canisters was measured using an Anderson cascade impactor calibrated to 28.3 L/min, and compared to commercial FP. The drug (FP) content of each particle size fraction was measured using ultraviolet spectrophotometry and the (99m)Tc level in each fraction was measured using an ionization chamber. The percentage of particles in the fine particle fraction (<;4.7 microm) and the percentage of (99m)Tc from commercial and radiolabeled canisters were compared. The mean (SD) % FP in the fine particle fraction, before and after label was 43.2 (1.8) % and 43.9 (2.6) %, respectively. The mean (SD) % (99m)Tc in the fine particle fraction was 42.1 (5.1) %. The mean %FP exiting spacer at (<4.7 microm) before labeling was not significantly different from the mean % FP exiting spacer at (<4.7 microm) after labeling (p > 0.05). The mean % (99m)Tc attached to particles at (<4.7 microm) after radiolabeling was not significantly different from the mean % FP levels (p > 0.05). The validation in this study indicates that (99m)Tc can act as a suitable marker for HFAFP, delivered via pMDI-spacer.
Journal of Aerosol Medicine 02/2006; 19(3):254-60. · 1.61 Impact Factor
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ABSTRACT: The aim of this study was to compare subjective measures (overall health assessment both by the study physician and the child's mother) with objective measurements of forced expiratory volumes (FEV(t)) and maximal flow at functional residual capacity V(max)FRC) in recurrently wheezy infants.
Sixteen wheezy infants (12 boys) aged 8-26 months were studied. A clinical assessment at visit 1 was followed by the run-in period during which day- and nighttime asthma symptom scores were obtained. The actual study period consisted of 2 visits when patient's lung function was assessed. The first of which was during an acute exacerbation (visit 2), while the second was when the infant was asymptomatic (visit 3). FEV(t) were obtained by the raised volume rapid thoracic compression technique (RVRTC) and V(max)FRC by the tidal volume rapid thoracic compression technique (TVRTC).
Mean FEV(t) but not mean V(max)FRC were significantly lower at visit 2 compared to visit 3 (FEV(0.5): p = 0.005, and FEV(0.75): p = 0.002; V(max)FRC: p = 0.15) and correlated well with overall health assessment by the study physician (FEV(0.5): r = 0.82, and FEV(0.75): r = 0.84), but not with the overall health assessment by the mother.
We have shown in the present study that objective measurements of FEV(t) from a raised lung volume correlate well with the overall health assessment by the study physician; this was in contrast to measurements of V(max)FRC in the tidal volume range. We therefore conclude that the RVRTC technique is a feasible method to assess and monitor obstructive lung disease in infancy.
Respiration 02/2002; 69(5):397-405. · 2.26 Impact Factor
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ABSTRACT: We tested the hypotheses that in early pregnancy smokers have lower urinary cotinine levels than nonpregnant smokers, and that pregnant nonsmokers exposed to passive smoke have higher cotinine levels than nonsmokers not exposed to passive smoke. This was a prospective, quantitative, comparative study of the urinary cotinine levels and smoking characteristics of pregnant and nonpregnant females. A urine specimen was collected from each subject and the cotinine/creatinine level determined using radio-immunoassay. A questionnaire regarding smoking status, health issues, and demographic variables was administered to each subject. There was no difference in cotinine level between pregnant smokers and control smokers. Pregnant nonsmokers with passive smoke exposure had higher cotinine levels than the same group not passively exposed. Confidence in ability to stop smoking was associated with lower numbers of cigarettes consumed, but was not reflected by lower cotinine levels. These data suggest that if the mother smokes, the fetus is exposed from conception to levels of nicotine which are as high as those in adult female smokers who are not pregnant. The level of fetal exposure to nicotine during early gestation is independent of intention to alter smoking behaviour. Women should be targeted for antismoking public health messages before conception.
Australian and New Zealand Journal of Obstetrics and Gynaecology 10/1997; 37(4):383 - 386. · 1.24 Impact Factor
