Explain the the neural pathways for cough.
There are receptors in the larynx, pharynx, the tracheobronchial tree, and the esophagus that can sense stimuli (via afferent connections via the vagus and laryngeal nerves) connect to the cough center of the brain in the brain stem. The brain, through efferent nerves, can control the diaphragm, intercostal muscles, laryngeal muscles, and abdominal muscles to create the cough.
True or False: You can get airway remodeling and histological changes with chronic cough.
What are the 3 phases (efferent pathway) of cough?
1. Inspiratory phase (inhale) 2. Compressive Phase (pressure increases with closed glottis/quasi val salva) 3. Expiratory phase (glottis opens)
Who is at risk for impaired cough?
- Interruption of afferent and/or efferent pathways of cough reflex - Altered sensorium (anesthesia, narcotics, sedatives, alcohol, coma, stroke, seizure, sleep) - Laryngeal/upper airway disorders - Tracheostomy tube - Restrictive and obstructive lung diseases (impaired mucociliary clearance) - neuromuscular diseases - supine in hospital bed
What happens if you have impaired cough?
Aspirate oropharyngeal or stomach contents Acute airway obstruction Pneumonia Lung abscess Respiratory failure/ ARDS (aspiration is a big risk factor for ARDS) Bronchiectasis Pulmonary fibrosis
What are complications of cough?
1. Result primarily from marked increase in intrathoracic pressure 2. Disruption of surgical wounds 3. Negative impact on QOL
What is acute cough? what are questions to investigate in acute cough?
Cough lasting less than 3 weeks Is it life threatening? Life-threatening Dx: pneumonia, severe exacerbation of asthma or COPD, PE, HF, or other serious disease Non-life-threatening Dx: Infectious (URTI, LRTI), exacerbation of pre-existing condition (asthma, bronchiectasis, UACS, COPD), environmental or occupational.
What can cause URTI (common cold)? How is it treated?
Causes: Viruses (e.g. rhinoviruses) Nasal congestion and drainage Post-nasal drainage irritates larynx Inflammatory mediators increase sensitivity of sensory afferents Treatment: Antibiotics are NOT indicated Decongestants, cough suppressants of questionable value (only to control symptoms but it doesn't help in resolving the infection)
What is lower respiratory tract infections (acute bronchitis)?
Cough, with or without phlegm Most bronchitis in otherwise healthy adults is caused by viruses (rhinovirus, adenovirus, RSV). If it's likely viral in origin, do not prescribe antibiotics.
What are some bacterial causes to consider for lower respiratory tract infection? How do you treat these?
Mycoplasma pneumoniae, chlamydophilia pneumoniae - treat with azithromycin (macrolide) Bordetella pertussis (whooping cough) - self limited
How do you make sure that a cough isn't a pneumonia?
CXR to make sure there isn't infiltrate
True or False: Every patient with bronchiectasis should get a culture
True. Always consider bacterial infection (gram negative rods, staph aureus, organisms resistant to antibiotics) when dealing with bronchiectasis. These patients are chronically colonized with bacteria so it's good to identify what flora is present.
What is subacute cough and what are the key questions to ask?
Cough lasting 3-8 weeks. Is it post-infectious? (did they have pneumonia, pertussis, bronchitis, etc recently?) If it's not post-infectious, work up is the same as chronic cough. Are antibiotics needed?
What is chronic cough?
Cough lasting more than 8 weeks.
What are the top 5 causes of chronic cough in adults that have normal CXR?
1. Upper airway cough syndrome 2. Asthma 3. Gastroesophogeal reflux disease 4. non-asthmatic eosinophilic bronchitis 5. neuropathic cough
True or False: Coughs can have more than one cause
True. If you only treat one cause, you won't fix the cough.
What are two things that you can discontinue that may help with a patient's cough?
Smoking, ACE Inhibitors
What is another name for upper airway cough syndrome?
Post-nasal drip syndrome
What is upper airway cough syndrome?
Secretions from nose/sinuses stimulate upper airway cough receptors. Inflammation increases receptor sensitivity and laryngeal inflammation.
What are classic symptoms of upper airways cough syndrome?
Tickle in throat, throat clearing, hoarding, nasal congestion, cough. However, keep in mind that some of these patients (about 20%) present only with cough.
What are some physical exam findings of upper airway cough syndrome?
Inflamed nasal mucosa, secretions in posterior oropharynx
What are some underlying causes for upper airway cough syndrome?
Allergies, chronic sinusitis, overuse of alpha-agonist nasal sprays
How do you treat upper airway cough syndrome?
Give 2nd generation anti-histamine with or without intranasal corticosteroid.
True or False: Asthma can present with only cough.
What is the connection between GERD and cough?
Micro aspiration of small amounts of gastric contents into the larynx and tracheobronchial tree results in laryngeal inflammation, cough, and hoarseness. Also, there is a theory that you don't even need aspiration and that the reflux of acid into the distal esophagus triggers vaguely mediated stimulation of the esophageal-troncheobronchial cough reflex.
True or False: GERD related cough is easy to diagnose and treat.
FALSE. it is really difficult to diagnose and treat.
What are effects of GERD on the larynx?
Edema and erythema
How can GERD cause a vicious cycle of cough?
Reflux leads to cough which leads to increased abdominal pressure which leads to more reflex
What are some classic symptoms of GERD?
heartburn, sour taste in mouth, cough Cough may be the only symptom in up to 75% of patients with GERD
What are the 2 diagnostics tests used for diagnosing GERD?
1. 24-hour esophageal pH-impedance probe (this is our best tool). It is a tube that goes into their nose and down their esophagus. It directly measures reflux and how high in the esophagus it goes. 2. Esophagram (2 minute study where barium is swallowed and imaged)
How do you treat GERD?
Gastric acid suppression with proton pump inhibitor (e.g. omeprazole) for greater than or equal to 2 months combined with diet and lifestyle modification. Nissen fundoplication (surgery) to tighten the esophageal sphincter.
What is non-asthmatic eosinophilic bronchitis?
eosinophilic airway inflammation without variable airflow obstruction or airway hyper responsiveness Spirometry: normal Methacholine challenge: normal Induced sputum: greater than 3% eosinophils
How do you treat non-asthmatic eosinophilic bronchitis?
Inhaled corticosteroid for greater than or equal to 4 weeks
What kind of cough depends on excluding other causes of chronic cough?
Neuropathic cough. This cough is triggered by low-level stimuli such as change in ambient temp, taking a deep breath, laughing, talking for a few minutes. Need to clear throat, globes sensation, tickle in throat. Neural injury can be from: Virus infection (post-viral vagal neuropathy) Chronic irritation/inflammation (PND, GERD) Environmental pollutants
How do you treat neuropathic cough?
Manage underlying irritants. Neuropathic medications include: amitriptyline gabapentin (up to 3 times a day)
D. order CXR
Always check chest X-ray! It's part of the basic workup so you don't miss anything.
True or False: cough induced by ACE inhibitors always goes away immediately when taken off the medication
False. It can take from 1 day to up to 4 weeks.
What is the most common cause of cough in children?
Viral URTI. This should resolve in 1-3 weeks
What is chronic cough defined as in children?
Cough lasting longer than 4 weeks
What are some things that can cause chronic cough in kids?
Asthma, sinus disease, GERD, chronic tobacco smoke exposure, environmental causes
Diagnosis: chronic cough related to asthma, early COPD, GERD
Treatment: inhaled corticosteroid/bronchodilator, proton pump inhibitor