Other Lung Tests

Exercise Challenge Testing: Assess hyperreactivity when [blank_start]heat[blank_end] and [blank_start]moisture[blank_end] are lost from upper airways during exercise. [blank_start]Bike[blank_end] or [blank_start]treadmill[blank_end] is used to get HR [blank_start]80[blank_end]-[blank_start]90[blank_end]% of max for [blank_start]6[blank_end]-[blank_start]8[blank_end] minutes. Monitor: ECG, BP and SpO2 Post exercise: Spiro is done [blank_start]immediately[blank_end] then every [blank_start]5[blank_end] minutes until [blank_start]FEV1[blank_end] reaches it's [blank_start]lowest[blank_end] then returns to normal. [blank_start]15[blank_end]% drop in FEV1 is a [blank_start]positive[blank_end] test If FEV1 drops by 10-15% administer a [blank_start]bronchodilator[blank_end]

Eucapnic Voluntary Hyperventilation: Assess airway hyperreactivity by havin pt breathe at high rate of [blank_start]ventilation[blank_end]. Removes [blank_start]heat[blank_end] and [blank_start]moisture[blank_end] from upper airway Pt breathes gas mix of [blank_start]5[blank_end]% CO2, [blank_start]21[blank_end]% O2, with balance [blank_start]N2[blank_end]. Spirometry is performed [blank_start]immediately[blank_end] after and every 5 minutes for [blank_start]20[blank_end] minutes. If FEV1 drops by [blank_start]15[blank_end]%, the test is positive. If FEV1 does not drop after [blank_start]20[blank_end] minutes, test is [blank_start]negative[blank_end] Bronchodilator to reverse any bromchospasm

Mannitol Tolerance Test Withhold SABA [blank_start]8[blank_end] hrs, all other meds [blank_start]12[blank_end] hrs. No [blank_start]caffeine[blank_end] Mannitol stimulates release of [blank_start]mediators[blank_end] that act on bronchial smooth [blank_start]muscle[blank_end]. Sensitive for asthma and used to [blank_start]monitor[blank_end] disease activity and assess [blank_start]antiinflammatory[blank_end] therapy. [blank_start]Dry[blank_end] powder in special inhaler. Color coded for [blank_start]0[blank_end], [blank_start]5[blank_end], [blank_start]10[blank_end], [blank_start]20[blank_end], [blank_start]50[blank_end] mg doses Full insp with 5 second hold is done with flow 60 L/min. After [blank_start]60[blank_end] seconds, do spirometry, repeat at higher doses until [blank_start]15[blank_end]% drop in Fev1 [blank_start]PD15[blank_end]% is reported Avoid smoking for [blank_start]6[blank_end] hours, avoid [blank_start]exercise[blank_end] on day of test

MIP Largest amount of [blank_start]negative[blank_end] inspiratory pressure that can be generated against an occluded airway Manometer with flanged mouthpiece and 3 way stopcock. Typical Value = [blank_start]-60[blank_end] cmH20 Pt expires to RV, occlude mouthpiece, pt inhales maximally for [blank_start]1[blank_end]-[blank_start]3[blank_end] seconds. Small [blank_start]leak[blank_end] is built in to offset cheek movement Assess muscles strength: Will be decreased in [blank_start]neuromuscular[blank_end] disease, disease involving diaphragm, chest wall or spinal deformities

MEP Maximum positive pressure that can be generated during forced expiration against occluded airway. Same equipment as MEP Typically [blank_start]80[blank_end] - [blank_start]100[blank_end] cmH2O Pt inhales to [blank_start]TLC[blank_end], airway occluded, then pt exhales forcefully Will be decreased with [blank_start]neuromuscular[blank_end] disease, especially generalized weakness. Decreased with emphysema, chronic bronchitis, CF and inability to cough.

Methacholine Challenge testing PC20 [blank_start]Provacative[blank_end] concentration used to determine if pt had [blank_start]positive[blank_end] methacholine challenge. The concentraion of methacholine that made pt drop [blank_start]20[blank_end]% in FEV1 Prohibited Activities Avoid any activity that may induce [blank_start]bronchospasm[blank_end]. Irritants, exercise, work

Methacholine Challenge Withholding Meds SABA withhold [blank_start]8[blank_end] hrs LABA withhold [blank_start]48[blank_end] hrs Anticholinergics withhold [blank_start]24[blank_end] hrs Combo Drugs withhold [blank_start]48[blank_end] hrs Theophyllines withhold [blank_start]12[blank_end]-[blank_start]24[blank_end] hrs Cromolyn Sodium / Nedecormil withhold [blank_start]8[blank_end] hrs Antihistamines withhold[blank_start]12[blank_end]-[blank_start]24[blank_end] hrs Steroids may [blank_start]not[blank_end] need to be withheld Beta Blockers may [blank_start]increase[blank_end] response Caffeine withhold [blank_start]6[blank_end] hrs

Methacholine Challenge Testing Pt inhales to [blank_start]TLC[blank_end] w/ 1-2 second pause for [blank_start]5[blank_end] breaths. Wait [blank_start]3[blank_end] min then do FVC Repeat at higher [blank_start]concentrations[blank_end] until [blank_start]20[blank_end]% reduction in FEV1 occurs Baseline [blank_start]FEV1[blank_end] determined from spiro First dose is saline and is a [blank_start]control[blank_end] Bronchodilator is given to reverse [blank_start]bronchospasm[blank_end]