Cough in palliative care

Cough- complex physiological mechanism that protects the airways and lungs by removing mucus and foreign matter from the larynx , trachea and bronchi and is under both voluntary and involuntary control

 

up to 40 % to 50 % of advanced cancer patients report cough up to 47 % to 86 % of lung cancer patients chronic cough ( > 8 weeks ) can be the presenting complain in over 65 % with lung cancer and 26 % of those with chronic lung disease in their last year of life also common in advanced chronic diseases as chronic obstructive lung disease , interstitial pulmonary fibrosis

 

Cough has a protective effect Cough can be provoked by stimulation of afferent C fibres ( chemoreceptors ) and A delta fibres (mechanoreceptors ) in the airways carried by the vagus nerve ie it can happen due to mechanical and chemical irritation of receptors in the respiratory tract Intact cough reflex requires ( a ) adequate respiratory muscles (b) closure of glottis (c ) dynamic compression of major airways ( d ) favorable mucus properties (e ) effective mucociliary clearance In cancer patients coughing can be less effective due to several factors as ( a ) cough inhibitors as pain , opioid (b ) exhaustion due to cachexia (c) muscle weakness for e.g due to neurological conditions ( d ) vocal cord involvement – for e,g head & neck cancers , recurrent laryngeal nerve involvement ( e ) stiffness of major airways ( f ) ↑↑ tenacity of mucus and ↓↓ mucociliary clearance.

 

Cancer related – directly caused by cancer airways obstruction and distortion pulmonary parenchymal involvement pulmonary infiltration pleural infiltration , pleural effusion mucus secretion and retention tracheo-oesophageal fistula ineffective cough due to vocal cord palsy , pain weakness lymphangitic carcinomatosis pulmonary leukostasis superior vena cava syndrome vocal cord paralysis

 

Indirectly caused by cancer – anorexia -cachexia syndrome pulmonary aspiration pulmonary embolus / microembolism paraneoplastic syndrome radiotherapy sequelae cough after chemotherapy/ radiotherapy

 

Non-malignant conditions – upper airway cough syndrome due to a variety of rhinosinus conditions infections / atelectasis / chronic bronchitis post infectious medications as ACE inhibitors , beta blockers gastro-oesophageal reflux COPD / asthma Cardiac causes as CCF

 

Why Important – cough can be distressing – physical and psychosocial impact Cough is not a symptom being measured routinely in cancer patients – hence it may not be seen as an important issue severe cough can lead to dyspnoea , nausea / vomiting , sleep impairment , chest and throat pain difficulty eating , incontinence , speaking may cause new problems as rib fracture chronic cough – social embarrassment leading to stress , social isolation relatives / carers may find it difficult to tolerate in an already cachexic patient further coughing may cause exhaustion and make it less effective

 

Assessment – duration – when did it start how often , severity triggers / relieving factors timing ( worse in the morning ? after a meal ? at night ) relation to food positional ? smoking – past / current / passive exposure productive / dry if productive -sputum colour , frequency, amount / blood any other associated symptoms ( e .g nasal discharge , stridor ,dyspnoea ) impact of cough on the physical , social and psychological well being any concerns that the patient may harbor for e.g fear of choking during a cough careful medication review.

 

Examination – tests auscultate the chest observe chest wall movements respiratory rate percussion note wheeze / stridor / crepitations assess the quality / character of cough and determine factors as
○ is it powerful enough to expectorate secretions
○ is it dry / moist / productive or non-productive consider investigations based on
○ person’s wishes and stage of illness
○ prognosis
○ clinical suspicion
○ if further investigations are going to influence management
○ if a referral to 2ary care is required

 

Approach – Treat underlying cause where possible taking into account
○ patient wishes
○ circumstances ( weigh the benefits / risks)
○ life expectancy
○ previous treatment Review medications Optimize current therapy – particularly analgesia as pain may inhibit effective coughing Address / acknowledge fear anxieties and provide written / verbal advice cough diary may be helpful multiple therapies could be used to control intractable cough a multi-disciplinary approach can be useful in supporting patients / family

 

Non-pharmacological measures – Directed at symptoms control Proper positioning Relaxation Eliminate environmental irritants and support smoking cessation where applicable Ventilation – open windows , use a fan , humidification Saline via nebulizers Chest physiotherapy ( for e.g forced expiratory huffing and other techniques ) Speech therapy strategies for dry cough
○ pursed lip breathing
○ replace cough with swallow
○ relaxed throat breathing
○ cough suppression education
○ distraction

 

Central acting – Though to work directly by controlling the excitability of the neural elements in the brainstem that produce cough

 codeine pholcodine dextromethorphan methadone morphine diazepam

 

Peripheral acting- These may inhibit the responsiveness of the afferent or efferent nerves of the cough reflex
 demulcents local anesthetics as lidocaine , benzocaine hexylcaine Hcl and tetracaine sodium cromoglycate ( in lung cancer pts ) humidifying aerosols

 

Demulcents – consider 1st line for symptomatic treatment examples – have soothing substances as simple linctus , glycerol based ones , syrup , honey , treacle ( generally harmless and inexpensive but some preparation may have high sugar content ) work by mechanically coating the mucosa of the pharynx and provide short term relief from irritation

 

Local anaesthetics – work by inhibition of stretch receptors in the lower respiratory tract , lungs and pleura examples include ○ Benzonatate 100-200 mg tds or as nebulizer
○ nebulized lignocaine / bupivacaine

 

Opiates – for severe , distressing cough all opioids used to treat cough would lead to typical opioid related SEs as sedation , constipation and nausea little scientific evidence exists allowing comparison of one opioid with another and there is no evidence ( ie no double blind trial with an adequate number of patients to have a sufficient statistical power ) that cough suppressant therapy can prevent coughing if a patient is already on opiates and getting PRN dose -but getting no benefit for cough , adding additional opiate for has no value consider anticipatory prescribing to manage opioid induced constipation , nausea and vomiting.

 

Morphine – consider trial of low dose IR morphine for e.g 1.25 mg qds prn – if using regularly consider changing to – low dose sustained release morhpine ( 5-10 mg ) but higher doses have not proven to be effective unlike in pain control

 

Codeine – 10 to 20 mg every 4-6 hrs PRN ( linctus or tablets ) data suggests it may improve cough but evidence in palliative setting is limited if a patient is already on a strong opiate using there is no rationale for using codeine linctus

 

a metabolite of codeine and is associated with less neurophsychological problems and constipation Dihydrocodeine 10 mg td

 

Dextromethorphan centrally acting non opioid which shares same benefits as hydrocodone works for 3 – 6 hrs , usual dose is 10-20 mg 4-6 hrly shown to be as effective as codeine beware interaction (cytochrome P450 system ) and serotonin syndrome if used with other serotonergic drugs

 

Pholcodine – opioid cough suppressant ( typical dose 10 mL qid ) suppression of unproductive cough and has a mild sedative effect with little to no analgesic effect.

 

Methadone – can be used as linctus or 1 mg in 5 ml of water or juice for specialist use

 

Dry cough – nebulized sodium chloride cough suppressants

Wet / moist cough- encourage expectoration with an effective cough nebulized saline solution ( for those who can expectorate ) – 2.5 mL o 5 mL qds mucolytic as carbocisteine to reduce viscosity of secretions 
○ CKS recommends a 4 week trial
starting dose of 750 tds which can be reduced to 750 bd or 375 tds once improved
○ use with caution in people with active peptic ulceration as it may disrupt gastric mucosal barrier humidifying the air or oxygen ( if needed ) in people with dry mouth altering body position physio referral for e,g to agents to reduce secretions as antimuscarinics.

 

Refractory cough- Refer for specialist treatment which may include use of
 inhaled cromoglicate sodium gabapentin , baclofen , thalidomide , Carbamazepine or amitriptyline nebulized lidocaine

 

Non-acid reflux- non acid reflux can be associated with chronic cough in some individuals consider use of metoclopramide or domperidone.

REFERENCES

1. Palliative Medicine Doctors Meeting – Cough in Cancer Patients Dr Tse Man Wah , Doris Caritas Medical Centre *The significance of cough in palliative care setting (hkspm.com.hk)
2. Palliative care pain and symptom control guidelines for adults fifth edition Greater Manchester Management Group *Palliative-Care-Pain-and-Symptom-Control-Guidelines.pdf (england.nhs.uk)
3. Palliative care handbook Wessex Palliative Physicians Ninth edition 2019 *Microsoft Word – GB 9th ed Final June 2019.docx (ruh.nhs.uk)
4. Berkshire Adult Palliative Care Guidelines Best Practice Document 2018 Version 2 NHS (berkshirewestccg.nhs.uk)
5. Management of cough Waikato District Health Board open (hospicewaikato.org.nz)
6. Opioids for cough Sean Marks MD , Drew A Rosielle MD Opioids for Cough – Palliative Care Network of Wisconsin (mypcnow.org)
7. Bonneau, André. “Cough in the palliative care setting.” Canadian family physician Medecin de famille canadien vol. 55,6 (2009): 600-2. Cough in the palliative care setting (nih.gov)
8. Bausewein, Claudia, and Steffen T Simon. “Shortness of breath and cough in patients in palliative care.” Deutsches Arzteblatt international vol. 110,33-34 (2013): 563-71; quiz 572. doi:10.3238/arztebl.2013.0563
9. Palliative care- cough CKS NHS Palliative care – cough | Health topics A to Z | CKS | NICE
10. BC Centre for Palliative Care Interprofessional Palliative Symptom Management Guidelines 2017 Grey-BCPC-Clinical-Best-Practices-13-Cough.pdf (bc-cpc.ca)
11. Scottish Palliative Care Guidlines Scottish Palliative Care Guidelines – Cough
12. Molassiotis, A., Smith, J.A., Bennett, M.I. et al. Clinical expert guidelines for the management of cough in lung cancer: report of a UK task group on cough. Cough 6, 9 (2010). https://doi.org/10.1186/1745-9974-6-9