©2014 mfmer | slide-1 the evaluation of chronic cough katrina m. hynes, bas, rrt, cpft assistant...
TRANSCRIPT
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The Evaluation of Chronic CoughKatrina M. Hynes, BAS, RRT, CPFTAssistant Supervisor, Mayo Clinic Pulmonary Function LabFocusMay 15-17, 2014
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BackgroundChronic Cough
• Definition: A cough that persists beyond 8 weeks
• Symptom-based problem
• Requires further diagnostic evaluation
• Social impact• Anxiety• Physical discomfort• Social and personal embarrassment• Reduction in quality of life
Iyer VN, Lim KG. Mayo Clin Proc. 88 (10) 1115-1126, 2013
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Lancet 317 1364-74, 2008
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BackgroundPrevalence of cough?
• Cross-sectional survey of 36 general practices.• 4003 Subjects• Prevalence of
chronic cough was 12%
• Severe 7%
Thorax 2006;61:975–979.
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BackgroundCauses of Chronic Cough
• Infectious
• Airways disorders
• Lung parenchymal disease
• Tumors
• Irritation of the external auditory meatus
• Upper airway cough syndrome (UACS)
• Esophageal causes (GERD)
• Drugs (ACE inhibitors and β-blockers)
• Airway irritants
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Clinical Practice Guidelines
January 2006; 129(1_suppl) Diagnosis and Management of Cough: ACCP Evidence-Based Clinical Practice Guidelines
• 70-90% of cases seen in clinical practice• Upper airway cough syndrome (UACS)• GERD• Asthma
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Evaluation of Chronic Cough in the Pulmonary Function Lab
• 43 staff• 24 procedure rooms• 150-250
patients/day
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Evaluation of Chronic CoughSpirometry
• Spirometry (meaning the measuring of breath) is the most common pulmonary function test (PFTs)
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Spirometry and the Obstructive pattern
• Asthma
• Chronic Bronchitis
• Emphysema
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Spirometry and the Restrictive pattern
• Intrinsic lung disease• IPF, sarcoidosis, etc.
• Extra-pulmonary • Pneumothorax, pleural
effusion, etc.
• Neuromuscular• ALS, myasthenia gravis etc.
• Chest wall: obesity, scoliosis, kyphosis
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Evaluation of Chronic CoughBronchial Provocation - Guidelines
• American Thoracic Society (ATS)• Guidelines for Methacholine and Exercise
Challenge Testing (Am J Respir Crit Care Med Vol 161. pp 309-329, 2000)
• ATS-ERS are in the process of revising – possible release late 2014
• Pulmonary Function Laboratory Management and Procedure Manual
• In revision• www.thoracic.org
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Challenge TestingDirect stimulus – Methacholine Challenge
Effector cells• Airway smooth muscle cells• Bronchial endothelial cells• Mucus producing cells
Airflow limitation
Indirect stimulus – Mannitol/Exercise
Intermediary cells• Inflammatory cells
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Methacholine Challenge Test
• Methacholine chloride is a parasympathomimetic (cholinergic) bronchoconstrictor agent
• Methacholine is derived from acetylcholine, a naturally occurring substance in the body, and can cause the airways to tighten and swell, in sensitive people.
• FDA-approved methacholine • Provocholine®
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Methacholine Test Methodology Protocols
• Five-breath dosimeter protocol
• Two-minute tidal breathing dosing protocol
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Methacholine Dosing Protocols 1999 ATS – “Dose-Doubling” Protocol
Diluent (optional)
0.031 mg/ml 1 mg/ml*
0.0625 mg/ml* 2 mg/ml
0.125 mg/ml 4 mg/ml*
0.25 mg/ml* 8 mg/ml
0.5 mg/ml 16 mg/ml*
*”Dose quadrupling”
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Methacholine Challenge Test
• Example:•Baseline FEV1 4.0L•Control (diluent) 3.75L•3.75*.8 = 3.0L•3.75*.9 = 3.38L•PC20 = 3.00L
Mottram CD Ruppel’s Manual of Pulmonary Function Testing 10th ed 2012
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Methacholine Challenge Test
CATEGORIZATION of BRONCHIAL RESPONSIVENESS
PC20 Interpretation(mg/ml)
> 16 Normal bronchial4.0 to 16 Borderline BHR1.0 to 4.0 Mild BHR (positive test)< 1.0 Moderate to severe BHR
ATS AJRCCM Vol 161. pp 309-329, 2000
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Mannitol Challenge Test
• Indirect and osmotic stimulant• Increases osmolarity of airway surface liquid• Release of inflammatory mediators from mast
cells and basophils (e.g leukotriene)
• Sugar alcohol, dry powder (stored below 25°C)
• Utilizes a special dry-powder inhaler (DPI)
• No diluent or nebulization required
• Aridol™
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Mannitol Challenge Test
• Aridol Kit• Aridol capsules (mannitol)• 1 empty capsule• Osmohaler inhaler device (DPI)
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Mannitol Challenge ProcedureDosing scheme
• Total maximum dose = 635 mg
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Mannitol Challenge TestProcedure
• Pre-challenge spirometry• FEV1 at least 60% of
predicted
• Administer mannitol using Osmohaler
• At 60 seconds perform spirometry
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Mannitol Challenge TestProcedure
• Perform 2 acceptable FVC maneuvers (according to ATS/ERS Guidelines). Use the higher of these two values to calculate the change in FEV1
• If Baseline FEV1 is >10% lower than pre-challenge FEV1 - stop challenge
• Calculate target FEV1
• highest Baseline value * 0.85
• Continue with subsequent dosages
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Mannitol Challenge TestReporting results
• Percent decrease in FEV1 from post 0 mg dose (Baseline) value
• PD15 - 2 decimal places in mg/mL (eg, 33.85 mg)
• 15% decline in FEV1 is a positive test • If no 15% fall in FEV1 after highest dose,
PD15 reported as greater than 635 mg (negative test)
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Evaluation of Chronic CoughExhaled Nitric Oxide
• Numerous biomarkers of inflammation that have been detected in exhaled breath
Therapeutic Advances in Resp Disease 2007 1;5
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Exhaled Nitric Oxide Guidelines
• 2005 ATS+ERS (www.thoracic.org)
• 2011 ATS Interpretation
Am J Respir Crit Care Med Vol 184. pp 602–615, 2011
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Exhaled Nitric Oxide
• eNO = FENO*
• eNO is an index of eosinophilic (allergic) airway inflammation.
• eNO is not increased with bronchospasm.
* The abbreviation for fraction of exhaled nitric oxide at a flow of 50mL/sec
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Exhaled Nitric Oxide Prolonged Cough
• 71 pts c/o prolonged cough• Bronchial asthma (30)• Cough variant asthma (18)• Bronchitis (8)• Others (15)
• Conclusion: FeNO could be used as a diagnostic marker of prolonged cough, especially for the differential diagnosis BA and CVA from EB and others.
Respiratory Medicine (2008) 102, 1452e1459
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Exhaled Nitric Oxide ICS responders
“Exhaled NO, A Predictor of Steriod Response” Smith AD, AJRCCM 2005.
• 52 patients presenting with undiagnosed respiratory symptoms in a single-blind, fixed-sequence, placebo controlled trial of inhaled fluticasone for 4 weeks.
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Exhaled Nitric OxideInstrumentation - Aerocrine
• Niox Flex•Chemiluminescence analyzer•FDA approved•Expensive (>$35,000)•Oral and nasal
• Niox Mino•Electrochemical •Hand-held, no vacuum pump
•Oral only•Less expensive (~$3 ,000)•Consumables per test (~$10.00)
Niox Flex
Niox Mino
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Exhaled Nitric OxideNormal or Abnormal?
• Low FENO: < 25 ppb, (< 20 ppb in children): implies no airway inflammation
• High FENO: >50 ppb (> 35 ppb in children) OR rising FENO (> 40% change from previously stable level): implies uncontrolled or deteriorating eosinophilic airway inflammation
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Evaluation of Chronic Cough Rhinoscopy
• Flexible rhinoscopy is a quick, office-based procedure used to examine the entire nasal cavity
• Can be used in the evaluation Upper airway cough syndrome (UACS)
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Evaluation of Chronic Cough24 Hour Laryngopharyngeal pH monitoring
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Evaluation of Chronic Cough24 Hour Laryngopharyngeal pH monitoring
• Gastroesophageal Reflux Disease (GERD).• Classic symptom: burning sensation in your
lower chest (heartburn). • Major cause of chronic cough• GERD may lead to Barrett’s esophagus, a
type of intestinal metaplasia] which is a precursor for carcinoma
• Laryngopharyngeal reflux (LPR) is similar to GERD
• Does not have the classic symptoms of GERD
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Evaluation of Chronic Cough24 Hour Laryngopharyngeal pH monitoring
• Laryngopharyngeal reflux (LPR) is sometimes termed “Silent reflux”
• Common symptoms:• Excessive throat clearing, sore throat• Persistent cough• Hoarseness• A "lump" in the throat that doesn't go
away with repeated swallowing
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Evaluation of Chronic Cough24 Hour Laryngopharyngeal pH monitoring
• New Diagnostic/Monitoring Technology
• pH measurement system revolutionizes pH testing.
• Technology uniquely capable of sensing and recording both aerosolized and liquid pH levels allows for less invasive placement
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Evaluation of Chronic Cough24 Hour Laryngopharyngeal pH monitoring
• Off PPI or H2blocker for 10 days prior to study
• System uses small catheter introduced via the naris and placed just behind/beside the uvula for the study
• Data collected via a transmitter that transfers to a recorder
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Journal of Voice, Vol. 23, No. 4, 2009
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The Journal of Family Practice | August 2011 | Vol 60, No 8
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• Pediatric cough is a common complaint in 35% of preschool children and 9% of 7–11-year-olds.
Current Opinion in Otolaryngology & Head and Neck Surgery 2011, 19:204–209
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Case 1
• 26 yo female referred for multiple pulmonary nodules and chronic cough
• #1 Multiple pulmonary nodules• r/o histoplasmosis. • PPD negative. • Pet exposure (kitty litter boxes, toxocara as
well as toxoplasma).
• #2 Increasing cough • The possibility of reflux is very strong.
• #3 Suspect obstructive sleep apnea
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Case 1
• Histoplasmosis – negative
• Toxocara Antibody - POSITIVE • This indicates exposure to the and does not
necessarily mean those nodules are active Toxocara infection. Toxocariasis is a human illness caused by immature parasite worms of either the dog roundworm (Toxocara canis) or the cat roundworm (Toxocara cati).
• Chronic cough and dental erosion • 24 Hour Laryngopharyngeal pH monitoring
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Case 124 Hour Laryngopharyngeal pH monitoring
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Evaluation of Chronic Cough
Iyer VN, Lim KG. Mayo Clin Proc. 88 (10) 1115-1126, 2013
Mayo Clinic’s Clinical Flowchart
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Questions & Discussion