Airway responsiveness could measured using different Pharmacological agonists such as methacholine and histamine, cold air, hypo and hyper osmotic solutions as well as other stimuli. To measure airway responsiveness, increment dose or concentrations of the stimuli should be administered usually by inhalation root, ,measuring a Pulmonary function test (PFT) indicating airway diameter such as forced expiratory volume in one second (FEV₁) or specific airway conductance (sGaw), constructing of dose (or concentration) response curve to stimuli and determination of dose (or concentration) causing specific reduction of measured PFT such as PD₂₀ or PD₃₅ (PC₂₀ or PC₃₅).

AHR to different stimuli including Pharmacological agonists and other stimuli is the hallmark of asthma but is also seen in COPD patients. It means that different stimuli at a low dose which is not affect airway diameter in normal individual can cause airway constriction in asthmatic patients. This is the reason when asthmatic patients exposed to low cold air, the environmental or food stimuli thy will get airway constriction and difficult breathing.  Measurement of airway hyper-responsiveness is one of the best diagnostic tool in diagnostic of asthma disease in early stage. However, it is seen in COPD patients as well as other respiratory diseases and even in heart diseases.  Airway responsiveness could measured using different Pharmacological agonists such as methacholine and histamine, cold air, hypo and hyper osmotic solutions as well as other stimuli. To measure airway responsiveness, increment dose or concentrations of the stimuli should be administered usually by inhalation root in a specific time intervals.  After a defined period of administration of each dose or concentration of stimuli, a pulmonary function test (PFT) indicating airway diameter such as forced expiratory volume in one second (FEV₁) or specific airway conductance (sGaw) should be measured. When the final dose or concentration of stimuli was administered and PFT was measured, a dose (or concentration) response curve to stimuli should be constructed. From dose (or concentration) response curve, a dose (or concentration) causing specific reduction of measured PFT such as PD₂₀ or PD₃₅ (PC₂₀ or PC₃₅) should be determined as the criteria of AHR. If This criteria was lower tha a defined unite, it will indicate AHR.

Program Detail:

Definition of AHR

History

Different stimuli used for measurement of AHR

Method of measurement of AHR:

Method of measurement of AHR using sGaw

Method of measurement of AHR using FEV₁

Method of measurement of AHR using dose of stimuli and determination PD₂₀ or PD₃₅

Method of measurement of AHR using concentration of stimuli and determination PC₂₀ or PC₃₅

Method of measurement of AHR using Pharmacological agonists such as methacholine and histamine

Method of measurement of AHR using cold air

Method of measurement of AHR using hyper or hypotonic solutions

Method of construction dose (or concentration) response curve.

Method of determination of PD₂₀ or PD₃₅ (PC₂₀ or PC₃₅)

Interpretation of AHR:

In asthma

In COPD

In other respiratory diseases

In heat diseases

Using AHR for Research purposes

In Human

In animal

In vivo

In vitro