Mechanical ventilation and high-efficiency vacuum cleaning: A combined strategy of mite and mite allergen reduction in the control of mite-sensitive asthma. Use of an 'evidence-based implementation' strategy to implement evidence-based care of asthma into rural district hospital emergency departments. Enhancing ventilation in homes of children with asthma: pragmatic randomised controlled trial. An internet-based interactive telemonitoring system for improving childhood asthma outcomes in Taiwan. Unfavorable mechanical effects of heat and moisture exchangers in ventilated patients. Effect of improved home ventilation on asthma control and house dust mite allergen levels. Clinical effectiveness of a mite allergen-impermeable bed-covering system in asthmatic mite-sensitive patients. Reduction in asthma morbidity in children as a result of home remediation aimed at moisture sources. Encasement of bedding does not improve asthma in atopic adult asthmatics.
The relationship between exposure to house dust mite (HDM) allergens and prevalence of sensitization to these allergens in patients with asthma has been confirmed in many studies. Mite population growth is regulated by humidity. Reducing humidity and removing allergen by efficient vacuuming should control mite allergen and reduce symptoms.
                We sought to investigate the effect of mechanical ventilation and high-efficiency vacuuming on HDM numbers and Der p 1 concentrations in the homes of mite-sensitive asthmatic subjects and to evaluate the effect of any reductions on symptoms.
                The homes of 40 HDM-sensitive asthmatic subjects were randomized to receive (1) mechanical ventilation and a high-efficiency vacuum cleaner (HEVC); (2) mechanical ventilation alone; (3) an HEVC alone; and (4) no intervention. Homes and patients were monitored for 12 months. Change in absolute humidity, mite numbers, Der p 1 concentrations, lung function, bronchial hyperresponsiveness, and symptom scores were analyzed.
                Homes with mechanical ventilation achieved significantly lower humidity levels than those without (P <.001), with an associated reduction of mite numbers (P <.05) and Der p 1 concentrations (P <.001 ¿in nanograms per gram, P =.006 ¿in milligrams per square meter) in bedroom carpets and some other mite sources in the ventilated areas of the homes. The addition of a vacuum cleaner enhanced this effect. There was a trend for an improvement in histamine PC(20) (P =.085) in the patients whose homes were ventilated.
                The use of a mechanical ventilation system in suitable homes resulted in some reduction in numbers of HDM and Der p 1 concentrations. The addition of an HEVC slightly enhanced the effect but not sufficiently to see an improvement in symptoms. To determine if an evidence-based implementation (EBI) could lead to the successful implementation of evidence based care for adult asthma in small rural district hospitals.
                A controlled trial involving eight small rural hospitals (four each in the study and control groups) was conducted. Retrospective pre-intervention audits were conducted at all eight hospitals for 7 months (1 January 2004 to 31 July 2004) and evidence-practice gaps identified. An EBI was then used to implement established guidelines for the management of asthma in the study hospitals. Post-intervention audits were then performed over a period of 7 months (1 October 2004 to 31 April 2005).
                There were 52 presentations of asthma in the study hospitals in the pre-implementation phase and 47 post-implementation. The corresponding numbers for the control hospitals were 46 and 42 respectively. There were no statistically significant differences in the severity between the groups. Following the EBI there were significant improvements at the study hospitals for the documentation of severity (8% to 62%, p <0.001), use of spirometry (12% to 62%, p <0.001) and the use of written short-term asthma plans (9% to 26%, p = 0.05). There was a decrease in use of ipratropium in mild asthma (44% to 30%, p = 0.228), an increase in the use of systemic steroids (61% to 72%, p = 0.255) and no change in prescribing antibiotics for afebrile patients with asthma (21% to 21% p = 0.956). There was no significant change in practice at the control hospitals except for a decrease in the use of systemic steroids (48% to 21%, p = 0.011). For the six clinical indicators aggregate there was a significant increase in compliance with guidelines at the study hospitals (36% to 62%, p < 0.001) but no change at the control hospitals (31% to 31%, p = 0.970).
                The pre-intervention audits demonstrated low levels of compliance with asthma guidelines across six clinical indicators. An EBI significantly improved compliance across these six indicators, and no improvement was noted in the control hospitals. This study demonstrates that an EBI can alter clinical practice in small rural district hospitals. Few robust studies have tested whether enhancing housing also improves health.
                To evaluate the effectiveness of installing ventilation systems, and central heating where necessary, in the homes of children with moderate or severe asthma.
                Pragmatic randomised controlled trial (RCT) in homes within Wrexham County Borough, Wales, UK.
                A pragmatic RCT was carried out, of a tailored package of housing improvements providing adequate ventilation and temperature, following inspection by a housing officer. One hundred and ninety-two children with asthma aged 5 to 14 years, identified from general practice registers, were randomised to receive this package, either immediately or a year after recruitment. At baseline, and after 4 and 12 months, parents reported their child's asthma-specific and generic quality of life, and days off school.
                The package improved parent-reported asthma-specific quality of life significantly at both 4 and 12 months. At 12 months, this showed an adjusted mean difference between groups of 7.1 points (95% confidence interval [CI] = 2.8 to 11.4, P= 0.001): a moderate standardised effect size of 0.42. The generic quality-of-life scale showed reported physical problems were significantly reduced at 4 months, but not quite at 12 months, when the mean difference was 4.5 (95% CI = -0.2 to 9.1, P= 0.061). The improvement in psychosocial quality of life at 12 months was not significant, with a mean difference of 2.2 (95% CI = -1.9 to 6.4, P= 0.292). Parent-reported school attendance improved, but not significantly.
                This novel and pragmatic trial, with integrated economic evaluation, found that tailored improvement of the housing of children with moderate to severe asthma significantly increases parent-reported asthma-related quality of life and reduces physical problems. Collaborative housing initiatives have potential to improve health. A randomized, controlled trial was conducted to assess the effectiveness of Blue Angel for Asthma Kids, an Internet-based interactive asthma educational and monitoring program, used in the management of asthmatic children. One hundred sixty-four (n = 164) pediatric patients with persistent asthma were enrolled and randomized into two study groups for a 12-week controlled trial. The intervention group had 88 participants who were taught to monitor their peak expiratory flows (PEF) and asthma symptoms daily on the Internet. They also received an interactive response consisting of a self-management plan from the Blue Angel monitoring program. The control group had 76 participants who received a traditional asthma care plan consisting of a written asthma diary supplemented with instructions for self-management. Disease control was assessed by weekly averaged PEF values, symptom scores, and asthma control tests. Adherence measures were assessed by therapeutic and diagnostic monitoring. Outcome was assessed by examining quality of life and retention of asthma knowledge. The data were analyzed by comparing results before and after the trial. At the end of trial, the intervention group decreased nighttime (-0.08 +/- 0.33 vs. 0.00 +/- 0.20, p = 0.028) and daytime symptoms (-0.08 +/- 0.33 vs. 0.01 +/- 0.18, p =0.009); improved morning (241.9 +/- 81.4 vs. 223.1 +/- 55.5, p =0.017) and night PEF (255.6 +/- 86.7 vs. 232.5 +/- 55.3, p =0.010); increased adherence rates (p < 0.05); improved well-controlled rates (70.4% vs. 55.3%, p < 0.05); improved knowledge regarding self-management (93.2% vs. 70.3%, p < 0.05); and improved quality of life (6.5 +/- 0.5 vs. 4.3 +/- 1.2 on a 7-point scale, p < 0.05) when compared with conventional management. The Internet-based asthma telemonitoring program increases selfmanagement skills, improves asthma outcomes, and appears to be an effective and well-accepted technology for the care of children with asthma and their caregivers. To investigate the mechanical effects of artificial noses.
                A general intensive care unit of a university hospital.
                10 patients in pressure support ventilation for acute respiratory failure.
                The following three conditions were randomly tested on each patient: the use of a heated humidifier (control condition), the use of a heat and moisture exchanger without filtering function (HME), and the use of a combined heat and moisture exchanger and mechanical filter (HMEF). The pressure support level was automatically adapted by means of a closed-loop control in order to obtain constancy, throughout the study, of patient inspiratory effort as evaluated from airway occlusion pressure at 0.1 s (P0.1). Patient's ventilatory pattern, P0.1, work of breathing, and blood gases were recorded.
                The artificial noses increased different components of the inspiratory load: inspiratory resistance, ventilation requirements (due to increased dead space ventilation), and dynamic intrinsic positive end-expiratory pressure (PEEP). The additional load imposed by the artificial noses was entirely undertaken by the ventilator, being the closed-loop control of P0.1 effective to maintain constancy of patient inspiratory work by means of adequate increases in pressure support level.
                The artificial noses cause unfavorable mechanical effects by increasing inspiratory resistance, ventilation requirements, and dynamic intrinsic PEEP. Clinicians should consider these effects when setting mechanical ventilation and when assessing patients' ability to breathe spontaneously. The warm, humid environment in modern homes favours the dust mite population, but the effect of improved home ventilation on asthma control has not been established. We tested the hypothesis that a domestic mechanical heat recovery ventilation system (MHRV), in addition to allergen avoidance measures, can improve asthma control by attenuating re-colonization rates.
                We conducted a randomized double-blind placebo-controlled parallel group trial of the installation of MHRV activated in half the homes of 120 adults with asthma, allergic to Dermatophagoides pteronyssinus. All homes had carpets steam cleaned and new bedding and mattress covers at baseline. The primary outcome was morning peak expiratory flow (PEF) at 12 months.
                At 12 months, the primary end-point; change in mean morning PEF as compared with baseline, did not differ between the MHRV group and the control group (mean difference 13.5 l/min, 95% CI: -2.6 to 29.8, P = 0.10). However, a secondary end-point; evening mean PEF, was significantly improved in the MHRV group (mean difference 24.5 l/min, 95% CI: 8.9-40.1, P = 0.002). Indoor relative humidity was reduced in MHRV homes, but there was no difference between the groups in Der p 1 levels, compared with baseline.
                The addition of MHRV to house dust mite eradication strategies did not achieve a reduction in mite allergen levels, but did improve evening PEF. Exposure to allergens plays a role in the development of bronchial hyperresponsiveness and in the chronic inflammatory response seen in asthmatic patients. House dust mites (HDMs) are an important source of allergen. Reduction of these allergens might lead to better lung function and reduction of asthma symptoms.
                The effect of HDM-impermeable covers on HDM allergen levels, peak flow values, and asthma symptoms were measured. Therefore a randomized clinical trial was carried out.
                Fifty-two allergic asthmatic patients were randomly allocated to use the HDM-impermeable or placebo covers. During the study period, daily peak flow and asthma symptom scores were recorded. Dust samples were taken from the mattresses.
                We observed a significant reduction in HDM allergen levels on the mattresses after encasing them with HDM-impermeable covers (reduction of 87% of Der p 1 in micrograms per gram of dust; P <.001). Baseline symptoms were so low that no improvement could be established. Morning peak expiratory flow is significantly higher in the intervention group compared with that seen in the placebo group during the study period (beta=20.2; P <.01).
                HDM-impermeable covers significantly decreased the level of HDM allergens. Furthermore, morning peak flow was significantly increased during the intervention period. This study indicates that HDM allergen-avoidance measures might have beneficial effects on allergen reduction and asthma outcome. Home dampness and the presence of mold and allergens have been associated with asthma morbidity. We examined changes in asthma morbidity in children as a result of home remediation aimed at moisture sources.
                In this prospective, randomized controlled trial, symptomatic, asthmatic children (n = 62), 2-17 years of age, living in a home with indoor mold, received an asthma intervention including an action plan, education, and individualized problem solving. The remediation group also received household repairs, including reduction of water infiltration, removal of water-damaged building materials, and heating/ventilation/air-conditioning alterations. The control group received only home cleaning information. We measured children's total and allergen-specific serum immuno-globulin E, peripheral blood eosinophil counts, and urinary cotinine. Environmental dust samples were analyzed for dust mite, cockroach, rodent urinary protein, endotoxin, and fungi. The follow-up period was 1 year.
                Children in both groups showed improvement in asthma symptomatic days during the preremediation portion of the study. The remediation group had a significant decrease in symptom days (p = 0.003, as randomized; p = 0.004, intent to treat) after remodeling, whereas these parameters in the control group did not significantly change. In the postremediation period, the remediation group had a lower rate of exacerbations compared with control asthmatics (as treated: 1 of 29 vs. 11 of 33, respectively, p = 0. 003; intent to treat: 28.1% and 10.0%, respectively, p = 0.11).
                Construction remediation aimed at the root cause of moisture sources and combined with a medical/behavioral intervention significantly reduces symptom days and health care use for asthmatic children who live in homes with a documented mold problem. We evaluated the impact of impermeable bed covers on asthma in asthmatics with clinically relevant house dust mite (HDM) sensitization.
                The study included 32 HDM-sensitized asthmatics in whom HDM allergy was considered as a significant factor in their asthma. They were randomized into either an intervention group whose bedding was encased with impermeable covers, or a control group who received cotton covers. Before and 3 and 6 months after encasement, dust samples were collected from the bedding and assayed for Der p 1. Clinical outcomes included quality of life, lung function, bronchial reactivity to methacholine, symptoms, medications and peak flow rates.
                Baseline Der p 1 levels in both the active and the placebo groups were comparable and high (19.2 vs 18.9 microg/g of dust). There was a significant reduction in Der p 1 levels in the active group after 6 months, but not in the placebo group (7.3 vs 21.9 microg/g of dust). Quality of life improved significantly in both the intervention and control groups, but there was no significant difference in the improvements between the groups. There was no significant change in lung function, symptoms, and requirements for medications.
                Encasement of bedding significantly reduced the Der p 1 levels. However, this was not sufficient to produce worthwhile clinical improvement in those in whom dust mite avoidance might well have been recommended as part of their clinical management.
                Copyright (c) 2006 S. Karger AG, Basel.
Evidence on clinical benefits of dehumidification using mechanical ventilation with dehumidifiers remains scanty, and the addition of a new double blind trial to this review does not indicate significant benefit in most measure of control of asthma from such environmental interventions.