#241 Chronic Cough

November 9, 2020 | By Cyrus Askin

“Ahem, Ahem”! A Rational Approach to Cough with Dr. Brad Hayward

Listen as our phenomenal guest Dr. Brad Hayward @bradleyjhayward (Weill Cornell Medicine) demystifies chronic cough for the primary care provider. Dr. Hayward, an internist, pulmonologist, intensivist AND palliative care physician sits down with us to discuss common causes for chronic cough, work up pearls and options for treatment. Follow him on Twitter, @BradleyJHayward. Listeners can claim free CE credit through VCU Health at http://curbsiders.vcuhealth.org/ (CME goes live at 0900 ET on the episode’s release date). We hope you enjoy learning from this episode as much as we enjoyed producing it!

Listeners can claim Free CE credit through VCU Health at http://curbsiders.vcuhealth.org/ (CME goes live at 0900 ET on the episode’s release date).

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Credits

• Written (including CME questions) and Produced by: Cyrus Askin MD
• Infographic by: Cyrus Askin MD
• Cover Art: Kate Grant MBChb, MRCGP
• Hosts: Matthew Watto MD, FACP; Stuart Brigham MD; Paul Williams MD, FACP   
• Editor: Emi Okamoto MD (written materials); Clair Morgan of nodderly.com
• Guest: Brad Hayward MD

Sponsor

Panacea Financial

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VCU Health CE

The Curbsiders are partnering with VCU Health Continuing Education to offer FREE continuing education credits for physicians and other healthcare professionals. Visit curbsiders.vcuhealth.org and search for this episode to claim credit. See info sheet for further directions. Note: A free VCU Health CloudCME account is required in order to seek credit.

How to Claim VCU CME Credit

Time Stamps

• Sponsor – Panacea Financial panaceafinancial.com
• Sponsor – VCU Health CE curbsiders.vcuhealth.org
• 00:00 Intro, disclaimer, guest bio; Guest one-liner and Pick of the Week*
• 06:23 Sponsor – Panacea Financial panaceafinancial.com
• 07:30 Case of Post Infectious Cough; Basic definitions for cough
• Important aspects of the history
• Empiric therapies for post-viral cough
• 22:50 Case of idiopathic chronic cough; Physical exam
• 29:20 Basic testing and empiric therapy for the common causes of chronic cough
• 41:51 When to refer to pulmonology; Therapy for idiopathic chronic cough; OTC cough meds
• 54:28 Take home message; Outro
• Sponsor – VCU Health CE curbsiders.vcuhealth.org

Cough Pearls

1. Subacute/chronic cough is one of the most common primary care complaints seen by providers
2. The most common cause for acute (and subacute cough) is active or recent viral infection (“post-viral cough syndrome”) for which a trial of inhaled corticosteroid is reasonable
3. Other common causes for cough include gastroesophageal reflux disease, post-nasal drip / upper-airway cough syndrome, cough-variant asthma and non-asthmatic eosinophilic bronchitis
4. The first step in evaluating cough should not be labs and imaging, but rather a thorough history focusing on things like onset, aggravating/alleviating factors, quality of the cough and exposure history 
5. Chest X-ray can be useful to identify major anatomic abnormalities, CT can be used later on if cough persists to rule out more subtle disease states
6. Basic spirometry can be helpful to identify obstruction early on in a patient’s course – save full pulmonary function testing for later
7. Don’t be afraid to try empiric therapies! Proton pump inhibitors, antihistamines, intranasal steroids and even inhaled corticosteroids are generally low-risk and will treat many cases of chronic cough 
8. Feel empowered to refer these patients to pulmonary… but also feel empowered to try the aforementioned therapies and start an initial work up

Chronic Cough Show Notes 

Basic Definitions

Cough can be defined as follows (Irwin, 2017):

• Acute: < 3 weeks
  • Usually seen in the setting of a viral infection causing airway hyperreactivity
  • Drs. Watto & Hayward recommend setting expectations with these patients: This will be an irritating, annoying process and the cough is often the last thing to go
• Subacute: 3 –  8 weeks
• Chronic: >8 weeks

History 101 – What’s Important per Dr. Hayward?

• • Sputum samples in tissues are not helpful!
  • Start open ended: Tell me about your cough.

• When did your cough start?

• What is it about your cough today, that made you feel it is time to be seen?

• Have you had this cough before? Any recent infections?
  • Post-viral cough due to post-viral airway hypersensitivity or post-nasal drip (Braman 2006)
• Is the cough productive or not?
  • Why: Productive cough may be associated with bronchiectasis or sinus disease. Dry cough can be seen in intrinsic lung disease or in association with certain drugs. (Smith 2016)
• History of asthma?
  • … and how did you get that diagnosis?
  • Have you ever done pulmonary function testing?
  • Itchy eyes / sore throat?
  • History of atopy? Response to bronchodilator? Hospitalizations/ED visits?
• History of reflux?
  • Classic symptoms of reflux are well known to cause cough and warrant treatment to include lifestyle modifications and PPI (Smith 2016)
  • The CHEST Guideline and Expert Panel Report from 2016 recommend against proton-pump inhibitor (PPI) therapy alone for suspected chronic cough due to reflux-cough syndrome without heartburn or regurgitation (Kahrilas 2016)
  • However, as discussed by Smith et. al. there is data supporting “intra-oesophageal reflux” as a cause for increased cough, perhaps due common vagal innervation of both the esophagus and trachea (Smith 2010)
  • Therefore, there may be a place for trial of PPI in these patients who do not experience classic reflux symptoms, and thus, in Dr. Hayward’s practice, he sometimes tries this as part of a comprehensive approach to treating cough
• Are your symptoms positional? Temporal? Association with a place, activities, times of year, environment(s), etc.?
  • Environment:
    • Animals – especially birds!
    • Occupational exposures (sandblasting, carpentry, asbestos)
    • Home (mold, cockroaches, HVAC)
  • Foods?
    • Primarily to screen for GERD
  • Smoking?
    • First, second and third-hand
• Meds: ACE-I? (Yilmaz 2019) 
  • ACE-I induced cough rate varies in reported studies, from 4% to 35% of patients!
  • ACE-I, prevent the action of ACE which normally would down-regularly bradykinin and substance P,  mediators that contribute to cough

Physical Exam Pearls

• • Dr. Hayward recommends several exam keys that can be helpful in assessing a patient with chronic cough
    • He reminds us that the exam begins when the patient is making their way to your office – keep an eye out for dyspnea on ambulation that may key you into a bigger problem than just cough
    • Nasal exam – looking for nasal polyps
    • Look for cobblestoning at the back of the throat – may be seen in post-nasal drip
    • Listen for wheezes, rales, ronchi
      • Consider a forced exhalation maneuver to identify asthma (“blow out birthday candles”)
    • Look for clubbing – may be a sign of more serious systemic disease (Spicknall 2005)

• As an aside… Why do we see clubbing? Perhaps the most promising theory:  megakaryocyte fragmentation into platelets occurs in lungs, pathologic processes which disrupt normal pulmonary circulation permit megakaryocytes to enter the systemic circulation which can get impacted in digital circulation. 

Approaching “undifferentiated” cough when there isn’t an obvious cause… 

As mentioned earlier, history is king! And always screen for post-viral cough.

Think common causes

Consider in any patient, the most common causes for subacute / chronic cough and, if you are comfortable, a trial of empiric therapy is certainly reasonable in the right clinical context (Michaudet 2017):

• Upper airway cough syndrome (aka post-nasal drip, can be allergic, non-allergic, etc.)
  • Empiric treatment: intranasal steroids +/- systemic antihistamines, reasonable to trial empiric therapy
• Gastroesophageal reflux disease / laryngopharyngeal reflux disease
  • Empiric treatment: trial of PPI – can be as long as 2-3 months, and some recommend twice-daily dose (Smith 2016)
• Asthma (cough-variant asthma)
  • Empiric treatment: initially with inhaled corticosteroid with close-interval follow up for clinical response (Côté 2020)
• … and non-asthmatic eosinophilic bronchitis (NAEB)- an emerging cause for unexplained cough in adults!
  • Empiric treatment: Also inhaled corticosteroid with close-interval follow up (Côté 2020)
  • Will often need intermittent inhaled corticosteroid (ICS) if a trigger/triggers cannot be identified and avoided

First-order testing

• • Chest X-Ray: Can help us identify significant abnormalities, or may suggest airway disease if clear
  • Pulmonary Function Testing: Spirometry up front (tells us if there is obstruction, or evidence for restriction) – Dr. Hayward doesn’t feel Full PFTs (spirometry + body plethysmography + DLCO testing) is required up front

• Look at the flow-volume loop!

• • Concern for allergies or environmental etiology? Dr Hayward recommends:
    • CBC with differential (looking for elevated eosinophils)
    • IgE level

• Serum allergy screen

Second-order testing

• Methacholine challenge test / bronchoprovocation: Can use if a patient has a normal flow-volume loop to provoke symptoms and obstruction
• Exhaled Nitric Oxide & Sputum Eosinophils: In Dr. Hayward’s practice, these tests can be nice to have access to if working up asthma/NAEB, but don’t often change management as these patients will have either already had or will receive empiric ICS – you may be better off trialing ICS in these patients and using their response to therapy as a means towards diagnosis 
• CT Scan: Upon referral or after referral, even with a normal CXR – this can find evidence of early interstitial lung disease (ILD), for example
  • Inspiratory & expiratory imaging is useful to identify air trapping
• Full PFTs: Can also be helpful in chronic, recalcitrant cough, also to identify evidence of air trapping (increased TLC, RV) or early ILD (decreased DLCO)
• Laryngoscopy / Speech Pathology: Can be helpful when evaluating for laryngeal disease / paradoxical vocal fold movement that can cause cough, which may be amenable to behavioral therapies (Gibson 2015)
• Bronchoscopy: In Dr. Hayward’s practice, he may pursue this in someone who has cough persisting for 6+ months with a normal work up, looking for an endobronchial lesion

Dr: Hayward’s Testing Take-Home

Sometimes a laborious work up is not as fruitful as an empiric trial of ICS – this will tell us if someone has NAEB or even asthma that was “missed” on spirometry since both should respond to a trial of ICS or can rule out a number of steroid-unresponsive conditions

Dr. Hayward’s pragmatic approach to treatment

• Post-nasal drip? Trial of intranasal steroid for 4-6 weeks
• Recent infection & airway hypersensitivity? Trial of inhaled corticosteroid (ICS) for 4-6 weeks
• What about albuterol? Dr. Hayward feels that for cough, it is not as effective because by the time they reach for their albuterol their coughing spell is often over already
• What about COVID?! – Dr. Hayward often sees patients after the ICU and prescribes 5-10 days of oral steroids, and he believes for others with prior history of COVID with post-viral cough symptoms that trialing inhaled corticosteroids is reasonable

Idiopathic chronic cough?

• Sometimes, you can’t find a cause – consider neurogenic cough (laryngeal sensory neuropathy) (Altman 2015)
  • Treatment options include trials of gabapentin, pregabalin, baclofen, or botulinum toxin
  • Gabapentin: 300mg daily, increase as tolerated/needed (Giliberto 2017)

When to refer?

• Dependent on primary care provider’s comfort level
• Often, if one or two trials of empiric therapy have failed, that’s a great time to send the patient to pulmonary

Links*

1. 90 Day Fiancé (show)  
2. Below Deck Mediterranean (show)
3. Mastering Communication with Seriously Ill Patients by  Anthony Back, Robert Arnold & James Tulsky (book) 

*The Curbsiders participates in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising commissions by linking to Amazon. Simply put, if you click on our Amazon.com links and buy something we earn a (very) small commission, yet you don’t pay any extra.

Goal

Listeners will develop a pragmatic approach to evaluating subacute and chronic cough in adult patients.

Learning objectives

After listening to this episode listeners will be able to…  

1. … define sub-acute vs chronic cough
2. … build a repertoire of history questions geared towards identifying the etiology of cough in a patient
3. … build a toolbox of diagnostic studies / tests that can be used in the evaluation of cough
4. … marry history, physical and diagnostic studies into a coherent approach to diagnosing subacute and chronic cough through a tiered/logical approach
5. … understand empiric therapies for cough that may have an advantageous risk-reward profile, even in the absence of diagnosis 
6. … educate patients on common causes for subacute cough and chronic cough, as well as how to appropriately set expectations regarding symptoms severity and duration

Disclosures

Dr. Hayward reports no relevant financial disclosures. The Curbsiders report no relevant financial disclosures. 

Citation

Askin CA, Hayward B, Williams PN, Brigham SK, Okamoto E, Watto MF. “241: Chronic Cough”. The Curbsiders Internal Medicine Podcast. http://thecurbsiders.com/episode-list Original Air Date: November 9, 2020.