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Biomedical subjects

C Reisner

Publications and source records attributed to C Reisner.

At least 19 recordsLinked to original sources
PubMed2001

Evaluation of particle size distribution of salmeterol administered via metered-dose inhaler with and without valved holding chambers.

BACKGROUND: Administration of inhaled medications to very young children is sometimes difficult. Administration of inhaled medications via metered dose inhalers (MDIs) to pediatric patients younger than 4 years of age requires use of a holding chamber/spacer with an attached facemask. OBJECTIVE: This in vitro study was conducted to determine the particle size distribution and overall dose of salmeterol delivered in conjunction with the use of various US-marketed valved holding chambers (VHCs) in comparison to the dose-delivered via MDI without VHCs. METHODS: Cascade impaction methodology with high-performance liquid chromatography was used to evaluate the fine particle mass (FPM) of salmeterol administered without and with the use of the following VHCs: Optichamber, medium and large Aerochambers, adult Aerochamber, and medium Aerochamber Plus. RESULTS: Particle size distributions for the Optichamber, various sizes of Aerochamber, and the Aerochamber Plus were very similar and the particle size distributions for all VHCs were similar to the distribution of the control. The FPM for particles ranging from 0.7 to <3.3 microm in diameter (in the range shown to provide the greatest lung dose to negotiate the small airways of infants) was similar across the various VHCs tested. Statistical comparison of the fine particle fraction for these stages shows a very similar profile when differences from the salmeterol MDI control were evaluated. CONCLUSIONS: In vitro results obtained under these test conditions demonstrate that all FPM values for the VHCs tested were within 15% of the control range, a difference that is unlikely to be clinically meaningful. These results indicate that the difference in FPM does not warrant a change in the recommended dosage of salmeterol administered when using the VHCs tested. Our results demonstrate that the use of an MDI and VHC provides a reasonable therapeutic approach for administration of salmeterol MDI to young children and other patients who have difficulties administering the MDI alone.

Administration, Inhalation↗
PubMed2001

Characterization of aerosol output from various nebulizer/compressor combinations.

OBJECTIVES: Different commercially available nebulizers and compressors are available. However, the optimal combination for drug delivery is unknown. METHODS: Flow rates of five different compressors (n = 3/compressor) tested alone and in combination with five different commercial nebulizers (n = 9 of each brand of nebulizer) were evaluated. Thereafter, the performances of the different nebulizers were evaluated using 2.5 mg albuterol solution (0.5 mL) added to 2.5 mL saline at flow rates of 2, 3, 4, and 5 L/minute using a laser particle analyzer. Volume median diameter and percentage of particles in the respirable range (1-5 microm) were calculated from this data. Time for nebulization (in seconds) and residual volume (in milliliters) were also recorded. RESULTS: The mean flow rates for the compressors evaluated without a nebulizer attached ranged from 6.6 L/minute (LifeCare Freedom-neb; LifeCare International, Lafayette, CO) to 12.2 L/minute (DeVilbiss Pulmo-Aide; DeVilbiss Health Care, Somerset, PA). Flow rates for the nebulizer/compressor combinations ranged from 2.08 L/minute (Pari LC Jet Proneb; Pari Respiratory Equipment, Richmond, VA) to 5.42 L/minute (Puritan Bennett Raindrop; Puritan Bennett, Lenexa, KS/Omron Compare; Omron, Health Care,Vernon Hills, IL). Using the repeated measure ANOVA model, the interaction between flow rate and device was significant (P < 0.001) for both percentage of particles in the respirable range and log volume median diameter. It was observed that the percentage of particles in the respirable range for the Pari LC Jet did not increase across flow rates in contrast to the other 4 nebulizers. All comparisons to the Pari LC Jet at 2 L/minute were significant. CONCLUSIONS: Marked variability exists in the flow rates among different commercially available compressors used for home nebulization of inhaled pulmonary medications. Different nebulizer/compressor combinations have markedly different performance characteristics which could result in different efficacy and safety profiles of the medications being administered via these devices. We recommend that this type of information be used as a starting point for selecting different nebulizer/compressor combinations. Further clinical evaluation is warranted.

Aerosols↗
PubMed2001

Switching from Ventolin CFC to Ventolin HFA is well tolerated and effective in patients with asthma.

BACKGROUND: Environmental imperatives to eliminate the use of chlorofluorocarbon (CFC) propellants in metered-dose inhalers have led to the development of metered-dose inhalers with the hydrofluoroalkane (HFA-134a) propellants. OBJECTIVES: To evaluate the clinical effect of switching from Ventolin CFC to Ventolin HFA and to compare the efficacy and safety of Ventolin CFC, Ventolin HFA, and placebo in patients with asthma. METHODS: Multicenter, double-blind, randomized safety and efficacy trial comparing regular use of Ventolin CFC versus Ventolin HFA versus placebo for 12 weeks in 313 patients with asthma aged 12 years and older who received Ventolin CFC during a 3-week run-in period. RESULTS: Patients who were switched from Ventolin CFC to Ventolin HFA maintained pulmonary function and other measures of asthma control at levels comparable with run-in baseline. Serial pulmonary function testing demonstrated that both Ventolin treatments had significantly greater mean improvement in FEV1 over baseline than the placebo group at treatment day 1 and weeks 6 and 12 (P < .001). Both Ventolin groups had comparable pulmonary function at every visit. Predose FEV1 values were maintained or improved over time with all treatments. Treatments were well-tolerated. The adverse event profile for both Ventolin treatments was comparable with placebo. No clinically relevant effects on ECG, vital signs, or clinical laboratory tests were noted. Asthma exacerbation rates were 4% to 5% in the Ventolin groups and slightly higher (8%) in the placebo group. CONCLUSIONS: Patients who were switched from Ventolin CFC to Ventolin HFA maintained comparable asthma control with a similar safety profile.

Adolescent↗
PubMed2000

Clinical comparability of ventolin formulated with hydrofluoroalkane or conventional chlorofluorocarbon propellants in children with asthma.

BACKGROUND: Aerosolized asthma medications with chlorofluorocarbon (CFC) propellants are being phased out because of environmental concerns about the ozone layer. Medications are being reformulated with non-ozone-depleting propellants. OBJECTIVE: To evaluate the clinical comparability of albuterol sulfate formulated in a new hydrofluoroalkane-134a (HFA) propellant (Ventolin HFA Inhalation Aerosol), and conventional CFC-containing albuterol (Ventolin Inhalation Aerosol) in children with asthma. DESIGN: Randomized, double-blind, placebo-controlled 2-week clinical trial with a 1- to 2-week run-in period. During the run-in, patients took Ventolin CFC as needed. Patients (n = 135) aged 4 to 11 years with asthma then were assigned randomly to treatment with Ventolin HFA, Ventolin CFC, or placebo administered 4 times daily via metered-dose inhaler for 2 weeks. All patients were allowed rescue albuterol use in matching propellant as needed for relief of breakthrough symptoms. The main outcome measure was the mean percentage of predicted peak expiratory flow (PEF) after the morning dose of study drug on day 1 and after 2 weeks as assessed by results of 6-hour serial tests. RESULTS: At day 1, the mean (+/- SE) percentage of predicted PEF increased postdose by 14% (+/- 1%) in the Ventolin HFA group and 13% (+/- 1%) in the Ventolin CFC group compared with 6% (+/- 2%) in the placebo group (P</=.006). At week 2, mean postdose increases were 11% (+/- 1%) in the Ventolin HFA and CFC groups compared with 5% (+/- 1%) in the placebo group (P<.001). There were no significant differences between the Ventolin HFA and CFC groups in postdose increases in pulmonary function, time to onset of response, duration of response, or peak effects. Safety profiles were similar among the 3 groups. CONCLUSION: Ventolin HFA is clinically comparable to Ventolin formulated with the conventional CFC-containing propellant when administered to children with asthma. Arch Pediatr Adolesc Med. 2000;154:1219-1225.

Aerosols↗
PubMed2000

Comparison of three commercial ultrasonic nebulizers.

BACKGROUND: The clinical acceptance of the initial ultrasonic nebulizers was impeded by their production of significant quantities of droplets larger than the respirable range that could have resulted in poor pulmonary deposition of nebulized medications. Subsequent modifications in the design of ultrasonic nebulizers have occurred. Overall nebulizer performance characteristics of the newer ultrasonic devices have not been evaluated. OBJECTIVE: Three commercially available ultrasonic nebulizers (DeVilbiss-Pulmosonic, Omron-Microair, Rhône Poulenc-Rorer-Fisoneb) were studied to compare the aerosol output characteristics. METHODS: The parameters studied were total volume output (TVO), time to nebulize total output (TTO), percent of droplets with volume diameters in the respirable range (PDVRR, 1 to 5 microm), albuterol concentration during nebulization, and the total drug delivered. All nebulizers were filled with 2.5 mL of saline and 0.5 mL of albuterol nebulizer solution. Three units from each manufacturer, each from a different lot, were evaluated in duplicate. RESULTS: The nebulizer with the largest volume output was the Omron (mean 2.94 mL), which also demonstrated the longest nebulization time (mean 10.3 min). The DeVilbiss and Rhône Poulenc-Rorer units delivered smaller volumes (mean 2.5 mL, 2.4 mL, respectively) but nebulized more rapidly (mean 2.21 min, 3.54 min, respectively). The Omron nebulizer generated the highest PDVRR with a mean of 38%. The DeVilbiss had a mean PDVRR of 16% and the Rhône Poulenc-Rorer a mean PDVRR of 21%. The majority of droplets from all three machines had a volume diameter smaller than the respirable range, ie, in the 0.5 to 1.0 microm range (Omron-60%, DeVilbiss-83%, Rhône Poulenc-Rorer-79%). For all three nebulizers there appeared to be no concentrating or diluting effect during nebulization implying that equal quantities of albuterol and diluent were delivered. The Rhône Poulenc-Rorer units demonstrated the greatest unit-to-unit variability with respect to TVO while the Omron units demonstrated the greatest unit to unit variability with respect to TTO. CONCLUSION: We conclude that several improvements in the design of ultrasonic nebulizers have resulted in the reduction of the size of the droplets generated. Our evaluation of the three commercially available ultrasonic nebulizers revealed that the majority of droplets generated were within or below the respirable range. There was no concentrating or diluting effect during nebulization for all three nebulizers. The output characteristics of the three devices differ and this will effect the delivery time as well as amount of drug delivered to the lungs.

Aerosols↗
PubMed1999

Analysis of inhaled corticosteroid and oral theophylline use among patients with stable COPD from 1987 to 1995.

STUDY OBJECTIVE: To document temporal usage trends for commonly used respiratory medications in patients with COPD. DESIGN: We retrospectively evaluated baseline concomitant medications of 3,720 patients with COPD enrolled in 10 bronchodilator clinical trials from 1987 to 1995. The proportion of patients in each trial using inhaled corticosteroids, inhaled beta-adrenergics, inhaled anticholinergics, oral theophylline, and oral corticosteroids was analyzed using the Cochran-Armitage trend test. PATIENTS: All patients had stable, moderate-to-severe COPD without evidence of asthma or atopy. Reversibility to beta3-agonists was not a requirement. RESULTS: The percentage of patients using inhaled corticosteroids increased significantly over time (p < 0.001) from 13.2% in 1987 to 41.4% in 1995. The percentage of patients receiving oral theophylline decreased significantly (p < 0.001) over this same time interval (63.4 to 29.0%). In addition, the percentage of patients using oral corticosteroids and the percentage using oral beta-adrenergics decreased moderately (p < 0.05) (30.1 to 16.4% and 11.7 to 4.5%, respectively); the percentage of patients using inhaled anticholinergics increased slowly (p < 0.05) (48.2 to 53.8%). The percentage of patients receiving inhaled beta-adrenergics did not significantly (p > 0.05) change. CONCLUSIONS: The observed changes in use of inhaled corticosteroids and theophylline were not likely related to differences in disease severity or other patient characteristics in the evaluated trials, but related to changing prescribing and COPD management practices.

Administration, Inhalation↗
PubMed1999

The combination of ipratropium and albuterol optimizes pulmonary function reversibility testing in patients with COPD.

STUDY OBJECTIVES: To determine whether the combination of ipratropium bromide and albuterol results in greater and more consistent pulmonary function test (PFT) response rates than ipratropium bromide or albuterol alone in patients with COPD. DESIGN: Retrospective review of two recently completed 3-month, randomized, double-blind, parallel, multicenter, phase III trials. SETTING: Outpatient. PATIENTS: A total of 1,067 stable patients with COPD. INTERVENTIONS: Ipratropium bromide (36 microg qid), albuterol base (180 microg qid), or an equivalent combination of ipratropium bromide and albuterol sulfate (42 microg and 240 microg qid, respectively). MEASUREMENTS AND RESULTS: PFT response rates were analyzed using 12% and 15% increases in FEV1 compared with baseline values and were measured in the various treatment groups on days 1, 29, 57, and 85 in these trials. Regardless of whether a 12% or a 15% increase in FEV1 was used to define a positive response, an equivalent combination of ipratropium bromide and albuterol sulfate was superior to the individual agents (p < 0.05; all comparisons within 30 min). In addition, a 15% or more increase in FEV1 was seen in > 80% of patients who received the combination of ipratropium and albuterol sulfate during the initial PFT and continued to be observed 3 months after initial testing. CONCLUSIONS: Use of a combination of ipratropium bromide and albuterol sulfate is superior to the individual agents in identifying PFT reversibility in patients with COPD.

Adrenergic beta-Agonists↗
PubMed1996

Comparison of volume output from two different continuous nebulizer systems.

BACKGROUND: Continuous nebulization is a safe and practical method of administration of beta 2-adrenergic agonists during acute asthma. There are essentially two types of continuous nebulizer systems; one utilizes a large volume nebulizer and the other a small volume nebulizer attached to a constant volume infusion pump. OBJECTIVES: We compared the volume output characteristics of these two systems. METHODS: Study performed at Danbury Hospital. Both types of continuous nebulizers were reconstructed as reported in the literature and output monitored hourly for four hours. A total of nine nebulizers from each type of continuous nebulizer was evaluated, three from each of three different lots. RESULTS: The volume output of the large volume nebulizer ranged from 37.7 to 55.4 mL/h with a mean of 45.96 mL/h (P = .0001). Contrasts within the repeated measure ANOVA revealed that all pairwise contrasts in time were significant (P < .05) except for the 60 and 120 minute means. The volume output of the small volume nebulizer ranged from 15.0 to 16.6 mL/h with a mean of 15.88 mL/h. There was a significant difference in the mean volume output across time for the 60-minute value only. No other significant differences were found. CONCLUSION: These data suggest that the small volume nebulizer utilized in this manner for continuous nebulization is a more consistent delivery device than the large volume nebulizer. Further data are required on both actual drug output and mass median aerodynamic diameter of the particles generated by these nebulizers before one can recommend a particular system.

Adrenergic beta-Agonists↗
PubMed1995

Continuous versus frequent intermittent nebulization of albuterol in acute asthma: a randomized, prospective study.

BACKGROUND: In acute severe asthma the optimal dose, frequency, duration and method of administration of beta-2 agonists is unknown. No study to date has evaluated the efficacy of high dose beta-2 agonists beyond the initial two hours. OBJECTIVE: (1) To determine whether high-dose continuous nebulization of albuterol (7.5 mg/h) is as safe and as efficacious as high-dose intermittent nebulization of albuterol (2.5 mg every 20 minutes) for four hours. (2) To evaluate whether there is a continual improvement using high dose therapy beyond two hours. METHODS: We devised a simple means of continuous nebulization calibrated to deliver 7.5 mg albuterol per hour. Twenty-two nonsmoking, patients with acute, severe asthma who presented to the emergency department with less than 60% predicted normal PEFR were randomized to either the continuous or intermittent group. All patients received intravenously 125 mg methyl prednisolone on initiation of the study. No theophylline was administered. Spirometry and vital signs were measured at baseline and every 30 minutes thereafter. Electrocardiograms were obtained on all patients and all patients had continuous cardiac monitoring. RESULTS: Both groups doubled their baseline spirometric values over the four-hour period (P < .0001). The FEV1 did not differ significantly between regimens at any time interval. Improvement from 120 minutes to 240 minutes was statistically significant (P < .0001). There was no significant difference in vital signs at the end of the study compared with baseline in either group, nor between the two groups at any time interval. CONCLUSION: High-dose continuous nebulization of albuterol is as safe and as efficacious as intermittent nebulization of albuterol in the early treatment of asthma in an emergency department. To our knowledge, this is the first study showing continued significant improvement beyond the initial two hours of therapy using high dose nebulized beta-2 agonists.

Acute Disease↗
PubMed1985

Do vitamin D supplements improve the physical capabilities of elderly hospital patients?

A randomized double-blind controlled trial of the effect of vitamin D supplementation on the abilities of elderly hospital patients to carry out basic activities of daily life is described. Those patients included in the trial had plasma 25-hydroxyvitamin D concentrations which were low or low normal as judged by the normal range in young adults. After 2 to 9 months on the trial there was no significant difference in the performance of the control and treatment groups.

Activities of Daily Living↗
PubMed1981

Arterial compliance, systolic pressure and heart rate in elderly women at rest and on exercise.

In two groups of elderly women, the relationships between arterial compliance estimated by pulse wave velocity (PWV), and systolic blood pressure (SP), heart rate (HR), oxygen consumption and the time taken to run 400 m have been studies. Both at rest and with increasing levels of exercise, faster PWVs are associated with higher SPs. These is a tendency for resting HR to be higher with faster PWVs. The changes in HR and oxygen consumption from resting values are strikingly increased with faster PWVs. The time taken over 400 m rises as arterial compliance falls. Therefore, it seems that, with aging, reduced arterial compliance is a major factor affecting cardiovascular responses to exercise.

Aged↗
PubMed1981

Franco-British disparities in medicine.

A questionnaire in French and English was sent to physicians practising geriatric medicine in France and the UK concerning certain aspects of their clinical practice. It also enquired of the doctors their place of practice, year of qualification, present position held, and in which part of the respective country they worked. Most of the answers reflect major divergencies in methods of clinical practice between the two countries. These answers are reported, highlighted, commented on, and speculation made of the possible reasons for the differences. We feel that international questionnaires are a useful way of alerting doctors to areas of practice which are falsely assumed to be correct; they may also reveal the possible basic solutions to common clinical problems.

Attitude of Health Personnel↗