Chronic Cough in Adults Flashcards
Red flags
Haemoptysis
Suspected malignancy or tuberculosis
About chronic cough in adults
95% of adult patients with non-productive cough and a normal chest X-ray will have:
. postnasal drip due to rhinorrhoea or sinus disease.
. chronic bronchitis due to eosinophils (asthma) or neutrophils (usually low grade infection).
. gastro-oesophageal reflux.
. side-effects from medication.
. a combination of these.
History of cough
. onset (> 75% begin after viral upper respiratory tract infection (URTI)), triggers, work environment, upper airway symptoms, sputum, aspiration, reflux.
. symptoms suspicious of malignancy e.g., haemoptysis, or voice change in smokers or ex-smokers.
. angiotensin-converting enzyme inhibitor (ACE inhibitor) or other medications.
. childhood asthma or bronchitis.
. smoking history.
. contact history and immunisation status e.g., whooping cough.
. snoring and sleep apnoea (these cause airway drying and increased reflux).
Assessment
Explore previous cough treatments and if there is evidence of:
. insufficient dose or duration.
. inadequate technique.
. poor compliance (most patients require 6 to 8 week trial to assess efficiency).
Consider common differentials:
. Post-infective cough
. Rhinosinusitis
. Chronic bronchitis due to eosinophils (asthma) or neutrophils (usually low-grade infection)
. Gastro-oesophageal reflux
. Angiotensin-converting enzyme inhibitors (ACE inhibitors)
. Snoring and sleep apnoea
. Micro-aspiration from tooth and gum disease – poor dental hygiene and tooth disease is a major risk factor for aspiration pneumonia and chronic cough, particularly in older adults who may also have swallowing or feeding difficulties.
Post-infective cough
An infective episode due to a viral, bacterial, or fungal aetiology may trigger a chronic cough due to the following:
* Exacerbation of asthma.
* Precipitation of non-asthmatic eosinophilic bronchitis.
* Precipitation of vocal cord dysfunction.
* The cough causing reflux which causes further coughing.
In post-infective cough, it is worth assessing the patient for other aetiologies or modifiable factors.
Rhinosinusitis
- Nasal discharge or congestion
- Postnasal drip
- Rhinorrhoea
- Sneezing
- Facial pain
- History of rhinosinusitis
Post-infectious cough is often aggravated or prolonged by any of the conditions above.
Asthma
- Nocturnal cough
- Chest tightness
- Dyspnoea
- Wheeze, worsened by exercise or other triggers
- History of atopy, hay fever, or both
Gastro-oesophageal reflux
- Coughing or choking during sleep
- Cough with eating or talking
- Associated acid or bile regurgitation (sour or bitter taste) at night
Up to 70% of patients with GORD-related cough are asymptomatic of reflux.
Angiotensin-converting enzyme inhibitors (ACE inhibitors)
- ACE inhibitors may exacerbate other causes of cough (uncertain mechanism but likely by way of reducing cough threshold)
- An ACE inhibitor related cough can take 3 months to resolve.
- Although ARB‑2 antagonists like candesartan are less likely to cause cough, it is a reported side-effect of treatment.
Investigation:
- Blood tests:
a. FBC, including eosinophils ( The probability of eosinophilic airway disease increases as blood eosinophil count increases e.g., a patient with eosinophil count 0.5 is more likely to have eosinophilic airway disease than a patient with eosinophil count 0.2.)
b. Total IgE
c. CRP
d. Brain natriuretic peptide (BNP) if possibility of heart failure:
. N-terminal pro-B-type brain natriuretic peptide (NT-proBNP), is a BNP test offered in the Auckland region. Unlike BNP, NT-proBNP levels are not affected by the use of sacubitril in Entresto.
. If NT-proBNP < 35 pmol/L, heart failure is unlikely (the “rule out” test).
. Preferably test before starting a diuretic or ACE inhibitor, as levels can fall quickly in response to treatment.
. Be aware of confounding factors:
- NT-ProBNP may be depressed by obesity and hypothyroidism, and by treatment with diuretics, vasodilators and ACE inhibitors.
- elevated by severe renal impairment, AF, LVH, valvular heart disease, and post-MI in the elderly.
- Women have slightly higher level than men.
- Chest X-ray (posteroanterior (PA) and lateral), if the patient has:
* lung cancer risk factors and a cough lasting ≥ 3 weeks
* haemoptysis which is not a clinical emergency, and local or minor causes are excluded
* not responded to 6-8 weeks of treatment
Arrange chest X-ray via Access to Diagnostics Funding (ATD) or a DHB eReferral (walk-in chest X-ray, or booked appointment).
- Spirometry.
- Sputum culture for productive cough.
Occasionally Aspergillus and non-tuberculous mycobacteria are reported on sputum culture. In the absence of a clinical picture (i.e., bronchiectasis) of Aspergillus lung disease, they are likely to be a contaminant. - Mycobacterial culture for tuberculosis if chest X-ray is suggestive.
Lung cancer risk factors
- Current or previous history of smoking
- Occupational exposure – most importantly asbestos
- Personal history of any cancer, including previous lung or head and neck cancer
- Family history of first-degree relative with lung cancer
- Pre-existing lung disease, in particular COPD, interstitial lung disease, and tuberculosis
- Passive smoking
- Heavy marijuana use
- Long-term exposure to air pollution
- Increasing age > 40 years
- Māori or Pacific ethnicity
Practice point in managemnet
Treatments may take up to 2 months to work.
Regular follow-up is important to ensure resolution or consideration of underlying persistent pathology e.g., lung cancer.
Consider and manage Micro-aspiration from tooth and gum disease:
- Poor dental hygiene and tooth disease is a major risk factor for aspiration and chronic cough, particularly in older adults who may also have swallowing or feeding difficulties.
- The practice of careful oral care by the patient or their caregivers, with attention to removal of remaining food from the teeth and mouth, and the possible use of antiseptic mouthwash, is likely to reduce this risk. 3
Manage Non-productive or minimally productive cough
- If voice change in smokers or ex-smokers, follow Hoarse Voice (Dysphonia) pathway.
- Eliminate any aggravating factors if possible.
- If the patient is on ACE-inhibitor, switch to ARB‑2 antagonists or alternatives. ACE-related cough can take 3 months to resolve.
- Offer smoking cessation advice.
- Aim treatment at suspected underlying cause:
- Asthma or chronic bronchitis
- Gastro-oesophageal reflux
- Snoring and sleep apnoea
- Pertussis (Whooping Cough)
- Rhinosinusitis
- Cough due to Long COVID.
- Over-the-counter cough medicines are rarely effective as they do not contain cough-suppressing doses of treatment. Consider codeine phosphate 15 mg, one to two tablets, 3 times a day or at night.
- If failed or inadequate response to treatment and cough persists despite normal chest X-ray and spirometry, request non-acute respiratory assessment.
