COUGH AND COUGH ADMIXTURE, CAUSE OF COUGH

Approach to cough

1. APPROACH TO COUGH AND SELECTING COUGH MIXTURE

2. COUGHING Cough is a sound produced by an attempt to expel an irritant during a forceful exhalation , while the term “cold” is used to refer to nasal discharge or blocked nose . Cough is an important defensive reflex . Cough is a symptom not a disease. Cough enhances clearance of secretions and particulates from the airways . 40% of the consultation activity .

3. COMPONENTS OF COUGH REFLEXES Bronchial submucosal glands ipsilateral vagus nerve glossopharyngeal , phrenic phrenic and spinomotor nreve recurrent laryngeal,vagal afferents to bronchial-tree RECEPTORS Laryngeal and tracheo -bronchial , Diaphragm , Pleura , oesophagus Rapidly adapting irritant receptors , non myelinated C fibres “COUGH CENTRE’’ Integration of afferents fibres in medulla, Separate to centres which control breathing EFFECTOR MUSCULATURE Expiratory muscles , Diaphragm , larynx , bronchial smooth muscle AFFERENTS EFFERENTS

4. COUGH REFLEX Generated from 3 main groups of receptors Respiratory mucosa (Oro-pharynx to terminal bronchioles) Lining the pleura Interstitium of the lung ( J receptors ) Other less important / aberrant receptors are in the external ear canal Oesophagus

5. Receptors in respiratory mucosa Are present right from the oro -pharynx to terminal bronchioles Stimulated by Inhaled irritants Oedema and inflammation Extrinsic pressure and deformation Presence of intra –luminal content Secretions Foreign body Aspirates

6. Lining the pleura Line both the parietal and visceral pleura Stimulated by injury Inflammation (dry pleurisy ) Foreign presence in pleural space Fluid- pleural effusion Pus – Empyema Blood – Heamothorax

7. The J receptors Discovered by Dr . A. S. Paintal J receptors or juxta – pulmonary capillary receptors Lie in interstitium of the lung Stimulated by increased interstitial volume ( pulmonary oedema or fibrosis ) increased pulmonary blood flow or pressure ( LVF )

8. COUGH : ANALYSIS AND APPROACH DURATION : Acute - less than 4 weeks Chronic - more than 4 weeks SPECIFIC OR NONSPECIFIC : Clues present or not DRY OR WET : Productive or not TIMING AND TRIGGERS : When and why

9. ACUTE COUGH Sudden onset Foreign body Coryza + child well URTI Stridor + barking cough Croup Tachypnea +retractions + crepts +wheeze Pneumonia / Bronchiolitis Rhinorrhea and sneezing / itching / block Allergic Rhinitis FTT / clubbing / chest deformity CF *Rule out Pneumonia *Rule out FB

10. ACUTE COUGH THAT RELENTLESSLY Pneumonia Mycoplasma Adenovirus Foreign body TB Mediastinal Adenopathy

11. RECURRENT VIRAL URTI Starts with a prodrome 50% resolve within 10 days 90% resolve within in 25 days 4- 8 respiratory infections per year in preschool age But parents may blend which land up in always coughing There will be a period of normalcy Growth development normal

12. HISTORY age of onset nature of onset Dry /wet cough Upper airway symptoms Cough at night Cough with feeds Cough during sleep PHYSICAL EXAMINATION FTT Clubbing Tonsils /Adenoids / Pharynx / Ear Allergic shiner Stridor Wheeze monophonic or localised

13. PRESCHOOL Airway malformation TEF Palato -pharyngeal incordination Chlamydiae / RSV/ Pertusis CF /PCD INFANT SCHOOL AGE FB Viral infections Asthma Passive smoke Asthma URACS Irritants Habit TB

14. DRY COUGH HYPERSENSITIVITY COUGH RECEPTORS HABIT COUGH , TOBACCO EXPOSURE ACE INHIBITORS PERTUSIS AUTOGENIC COUGH

15. WET COUGH GROWTH NORMAL WITH URI WITHOUT URI < 2 WEEKS ACUTE VIRAL CORYZA >2 WEEKS SINUSITIS , ALLERGIC RHINITI > 4 WEEKS PROTRACTED BACTERIAL BRONCHITIS

16. WET COUGH GROWTH COMPROMISED CYSTIC FIBROSIS PRIMARY CILLARY DYSKINESIA IMMUNODEFICIENCY NECROTISING PNEUMONIA NEGLECTED FB MIDDLE LOBE SYNDROME

17. HABIT COUGH DRY HONKING INCREASE WITH ATTENTION LA BELLE DIFFERENCE

18. STACCATO COUGH COUGH WITH EACH BREATH STACCATO COUGH CHLAMYDIAE

19. CROUP / LARYNGITIS BARKING COUGH CHANGE OF VOICE HOARSNESS OF VOICE

20. CROUP

21. PROTRACTED BACTERIAL BRONCHITIS WET COUGH >4 WEEK CHEST CLEAR AUSCULTATION- NORMAL X RAY CHEST –NORMAL TREATMENT- AMOXY-CLAV FOR 2-4 WEEK CLINICAL DIAGNOSIS IS SUFFICIENT, UNLESS RECURRENT

22. TIMING MATTERS SUDDEN ONSET – FB IMMEDIATELY AFTER LYING DOWN – GER COUGH SOMETIMES AFTER LYING DOWN POST NASAL DRIP NOCTURNAL AND EARLY MORNING – ASTHMA COUGH AFTER WAKING UP IN MORNING – BRONCHIETASIS

23. PERSISTENT RECURRENT ATOPY PRETERM ASPIRATION NO FEVER WITH FEVER BACTERIAL VIRAL TB PERTUSIS FB REASSURE URTI LRTI ADENOID SINUSITIS CF PCD PID COUGH

24. CHRONIC RECURRENT COUGH YES BREATHLESSNESS NO NOISY BREATHING YES NO STRIDOR TRACHEO BRONCH MALACIA WHEEZE ASTHMA XRAY CHEST NORMAL BRONCHITIS ABNORMAL CT CHEST URTI RHINITIS SINUSITIS PHARANGITIS TONSILLITIS

25. YES , TO EITHER XRAY CHEST WORK UP AS INDICATED CONSIDER ETIOLOGIES TO THE RIGHT NORMAL ABNORMAL NO TO BOTH URTI <2 WEEKS- Acute viral coryza (observe) URTI>2WEEKS -Sinusitis, Adenoiditis( Amoxycillin ) 1-4 WKS PREECEDED BY URTI – Post viral (observe) COUGH INTENSE PAROXYMAL /POST TUSSIVE VOMITING – Pertussis / Mycoplasma /Chlamydia- Azithromycin RHINORRHEA WITH SNEEZING –Allergic rhinitis- Antihistaminics WET COUGH > 4 WEEKS –PBB- Amoxy -clave NOCTURNAL COUGH , TRIGGER INDUCED , RECURRENT –Asthma-ICS DRUGS - Enalapril / Propranolol EAR –FB -Autogenic cough –Arnold reflex GEOGRAPHY –Environmental irritants DRY , HONIKING NEVER AT NIGHT –Habit cough COUGH MORE THAN 4 WEEKS OR RED FLAGS Sudden onset Weight loss / FTT Hypoxia Tachypnea Clubbing Immunosuppression Abnormal Lung / cardiac examination

26. SPUTUM COLOR CLEAR MUCOID CLOUDY PURULENT FOUL SMELLING PURULENT NON FOUL SMELLING RED ASTHMA CYSTIC FIBROSIS BRONCHIECTASIS INFECTION AIRWAY BLEED,HEMOSIDEROSIS , KLEBSEILLA

27. COUGH MEDICATION BASICALLY OF TWO TYPES COUGH SUPPRESSANTS EXPECTORANTS

28. COUGH SUPPRESSANTS Meant to suppress the cough reflexes. True ‘anti tussives ’ Usually used in dry cough

29. EXPECTORANTS Meant to improve expectoration Reduce cough by improving its efficiency ‘ pro – tussives ’ Used in wet cough

30. COUGH SUPPRESSANTS ACTING PERIPHERALLY BY SUPPRESSING RECEPTORS LOCAL ANESTHETICS Lignocaine , benzonatate , ambroxol DEMULCENTS Honey , glycerol , liquorice HUMIDIFICATIONS Plain steam , tincture benzoin BRONCHODILATORS *Effective only if cough arises from receptors in the mucosa

31. Cough suppressants acting on CNS –(opiates ) Codeine  1mg/kg/dose , CNS sedation ,GI side effects ,addiction Dextromethorphan  0.5 to 1.5 mg /kg/dose ,safer Pholcodeine  more potent, longer half life Noscapine  similar to dextro , potent releaser of histamine NON OPIATES- Levopropoxyphene , chlorphedianol

32. EXPECTORANTS stimulating bronchial glands AMMONIUM CHLORIDE , CITRATE popular but unproven GUAIACOLS guainphenesin (most popular ) VOLATILE OILS menthol , terpineinol , chlorthymol , camphor , eucalyptus oil IODIDES

33. EXPECTORANTS Reducing viscosity of sputum Steam Trypsin , chymotrypsin Iodides Bromhexine , ambroxol N acetyl – cysteine

34. N ACETYL CYSTEINE Breaks disulfide bonds in mucus and liquefies it, making it easier to expectorate Therefore particularly useful in abnormally thick mucus in CF , COPD, bronchiectasis and pulmonary fibrosis patients Available as oral, inhalation , tablets

35. MUCOLYTICS : Drugs aiming to decrease the viscosity of bronchial secretions, act to make secretions easier to clear through coughing .( Bromhexin / Ambroxol ) ANTIHISTAMINE –DECONGESTANT COMBINATION : Drugs that are combined antihistamine H1 receptor antagonist and alpha adrenoreceptor agonists , act by causing vasocostriction of mucosal blood vessels thus reducing congetion .

36. DEMULCENTS : They form coating and soothe the inflamed pharangeal mucosa , thereby reducing the frequency and strength of the afferent impulses transmitted to the cough center .(honey) BRONCHODILATORS : Only useful in case of wheeze associated cough like Bronchiolitis , WALRI or Asthma .( Salbutamol and Levosalbutamol )

37. CLINICAL APPROACH TO TREATMENT DRY COUGH Ignore Use cough suppressant

38. CLINICAL APPROACH TO TREATMENT WET COUGH

39. RATIONAL TREATMENT OF COUGH What is underlying cause ? treat the cause) Is treatment necessary ? ( severity of cough ) Is cough useful or useless ? (type of cough ) Encourage simple home remedies humidification ,lozenges ) Anti – tussive to be used ? ( DOC – dextrometharphan ) Expectorants to be used ? non definitely proven)

40. Take home message Detailed history often is helpful to arrive at a provisional diagnosis and physical examination and relevant investigations to reach the diagnosis. Give correct dose and frequency Do not use irrational combinations May use mixtures with other ingredient if associated symptoms are presents If using mixtures choose one with all drug in right proportion Consider side effects of other medication on the cough