Clinical Trial: Different End Points for Bronchial Hyperactivity (BHR) Tests.

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: Different End Points for Bronchial Hyperactivity (BHR) Tests, What Comes First?

Brief Summary:

Bronchial challenge tests (BCT) are being used to diagnose bronchial hyperactivity (BHR) and quantify its severity.In older children and adults, BCT is done using spirometry to measure the value of 20% fall in FEV1 as an indicator for positive reactivity.

However, in young children and infants that cannot perform spirometry, other measurements are used as indicators for BHR. Traditionally, in these populations, appearance of wheezing on auscultation is used as the indicator for BHR. More recently, other measures like 50% increase in respiratory rate or 5% decreases in oxygen saturation are mentioned as possible options to determine positive BHR. Nevertheless, as these measurements probably measure different parameters they could vary in time of appearance.

The investigators also noted that in older children who perform spirometry, the order of appearance of these different physiologic measures is not constant.

Decrease in O2 saturation, appearance of wheezing and increase in respiratory rate (RR) do not all appear at the same time and not in the same order of events.

Some children are noted to have a decrease in FEV1 without wheezing - those children can be difficult to diagnose as asthmatics in the primary care setting where asthma is being diagnosed on clinical grounds alone: wheezing and response to bronchodilators. Children who do not wheeze are difficult to diagnose and therefore, are not getting the appropriate treatment.

Nevertheless, the data in current literature is very scant or not existing regarding these issues. Thus the investigators designed a study to prospectively try to answer the questions: do clinically significant differences exist in the concentration of

Detailed Summary:

Bronchial challenge tests (BCT) are being used to diagnose bronchial hyperactivity (BHR) and quantify its severity.

In older children and adults, BCT is done using spirometry to measure the value of 20% fall in FEV1 as an indicator for positive reactivity. However, in young children and infants that cannot perform spirometry, other measurements are used as indicators for BHR. Traditionally, in these populations, appearance of wheezing on auscultation is used as the indicator for BHR. More recently, other measures like 50% increase in respiratory rate or 5% decreases in oxygen saturation are mentioned as possible options to determine positive BHR. Nevertheless, as these measurements probably measure different parameters they could vary in time of appearance.

The investigators also noted that in older children who perform spirometry, the order of appearance of these different physiologic measures is not constant.

Decrease in O2 saturation, appearance of wheezing and increase in respiratory rate (RR) do not all appear at the same time and not in the same order of events.

Some children are noted to have a decrease in FEV1 without wheezing - those children can be difficult to diagnose as asthmatics in the primary care setting where asthma is being diagnosed on clinical grounds alone: wheezing and response to bronchodilators. Children who do not wheeze are difficult to diagnose and therefore, are not getting the appropriate treatment.

Nevertheless, the data in current literature is very scant or not existing regarding these issues. Thus the investigators designed a study to prospectively try to answer the questions: do clinically significant differences exist in the time of appeara
Sponsor: Wolfson Medical Center

Current Primary Outcome: Which of the outcome ends points measures comes first in the diagnosis of bronchial hypersensitiveness. [ Time Frame: On which metacholine and / or adenosine increasing concentrations, there are 20% fall in FEV1 and / or 5% decrease in saturation and / or 50% increase in RR. Which comes first. Time frame: each BHR tests last up to two hours. ]

Increasing concentrations of Metacholine or adenosine inhalations are given until there are 20% fall in FEV1 and / or 5% decrease in saturation and / or 50% increase in RR. The concentrations on which these outcomes occur are measured.


Original Primary Outcome: Which of the outcome ends points measures comes first in the diagnosis of BHR. [ Time Frame: On which metacholine and / or adenosine increasing concentrations, there are 20% fall in FEV1 and / or 5% decrease in saturation and / or 50% increase in RR. Which comes first. Time frame: each BHR tests last up to two hours. ]

Increasing concentrations of Metacholine or adenosine inhalations are given until there are 20% fall in FEV1 and / or 5% decrease in saturation and / or 50% increase in RR. The concentrations on which these outcomes occur are measured.


Current Secondary Outcome: Age influence on which comes first outcomes. [ Time Frame: The time frame of the study: four years. ]

Age in years and months will be recorded. Age influence on the distribution of the main outcome - which comes first - will be calculated.


Original Secondary Outcome: Age influence on which comes first outcomes. [ Time Frame: The time frame of the study: two years. ]

Age in years and months will be recorded. Age influence on the distribution of the main outcome - which comes first - will be calculated.


Information By: Wolfson Medical Center

Dates:
Date Received: July 26, 2011
Date Started: September 2011
Date Completion:
Last Updated: December 10, 2014
Last Verified: December 2014