Respiratory Flashcards
Function of Respiratory Tract?
- Exchange carbon dioxide from blood with oxygen from lungs.
- Exchange takes place where pulmonary capillaries are in direct contact with the linings of the lung terminal air spaces(alveoli).
What makes up the respiratory tract?
- Upper respiratory tract (structures located outside the thorax; nasal cavity, pharynx & Larynx)
- Lower respiratory tract (located almost entirely within the thorax; trachea, bronchial tree, lungs)
- Oral cavity, Ribcage & Diaphragm
What is the Nasal Cavity?
- Internal portion of the nose
- Lies over roof of mouth
- Hollow structure separated by midline partition (septum). The septum has rich blood supply.
Cavity divided into: larger respiratory region, smaller olfactory region.
Cavity is connected to the pharynx through two openings(internal nares).
- Region is lined with cilia; filters out large dust particles.
- Inhaled air circulates cavity being warmed by close contact with blood from capillaries.
- Mucus secreted by goblet cells helps moisten the air.
What Is the Pharynx?
- Tubelike structure.
- Approx 12cm long.
- Serves as common pathway for respiratory and digestive tracts.
- Has 3 anatomical divisions: nasopharynx, oropharynx & laryngopharynx.
- Lined with ciliated mucous; helps remove large dust particles.
- Changes shape to allow vowel sounds to be formed during speech.
What is the Larynx?
Voice Box
- Triangular shaped
- Short passage connecting pharynx & trachea(lies in middle of neck)
- Protects airways against entrance of liquids/foods during swallowing: through glottis & epiglottis which act as trap doors to ensure liquids/food routed into oesophagus & not trachea.
- Lined with ciliated mucous; helps remove large dust particles.
What is the Trachea?
Windpipe
- 11cm tube
- Lies in front of oesophagus
- Extends from larynx to fifth thoracic vertebra (where divides into right & left bronchi.)
What’s is the Bronchi
- Trachea divides at fifth thoracic vertebra into left & right bronchi.
- Each bronchi divide & subdivide into bronchioles (resembling upside down tree, giving rise to bronchial tree term)
- Divisions continue till form terminal bronchioles
- From terminal bronchioles alveolar ducts & sacs exist; walls of which consist of alveoli where gaseous exchange takes place.
- Bronchial tree is lined with epithelial acting as a defence mechanism known as mucociliary escalator; cilia on surface beat upwards in organised waves of contraction to expel foreign bodies.
What do the Lungs consist of?
- Paired, cone-shaped organs within thoracic cavity.
- Divided into lobes; left has 2 lobes, right has 3.
Thoracic cavity - Role
- Important role in respiration; larger when chest raised/smaller when lowered affecting inspiration/expiration.
Pleural Membrane - What is it/Role
- Encloses the lungs; inner membrane covers lungs, outer membrane is attached to thoracic cavity.
- If Plura inflamed respiration becomes painful
Pleural Cavity - What is it/Role
Between Plural Membranes
- Contains fluid
- Prevents friction between membranes during breathing.
What is Coughing
- Body’s defence mechanism; attempts to clear airways of foreign bodies/particulate matter
- Most common respiratory symptom; manifestation of abnormalities of respiratory tract.
- Can be productive (chesty) or non-productive (dry/tight/tickly)
- Usually self limiting & will resolve in 3-4 weeks without antibiotics (British Thoracic Society Guideline 2019)
What is Mucociliary Escalator
- Defence mechanism of airways against foreign bodies/particulate matter.
- Consists of upward beating of finger-like cilia in bronchi moving mucus and entrapped forging bodies to be expectorated or swallowed.
Issues With A Cough
- Debilitating to patients well-being
- Disruptive to family, friends, work colleagues
Acute Cough
CKS Definition
- Cough present for less than 3 weeks
- Can take up to 4 weeks or more to fully resolve though.
Subacute cough
CKS Definition
- Cough present for 3-8 weeks
Chronic Cough
CKS Definition
- Cough present for more than 8 weeks
Referral Criteria For Cough
- Coughs other than acute (>3 week duration)
Acute Cough - Cause
- Usually caused by viral upper respiratory tract infection (URTI)
- School children experience > cough episodes yearly than adults.
Upper Respiratory Tract Infection (URTI) - Aetiology
90% caused by viruses:
- respiratory syncytial virus
- rhinovirus
- viral influenza
[Exhibits seasonability with higher viral URTI incidence seen in winter months]
10% caused by bacteria:
- Streptococcus pneumoniae
- Haemophilus influenza
- Staphylococcus aureus
- Klebsiella pneumoniae
these infections often have a viral element
- Reflex Process
Cough Production Process
Five Part Reflex
1. Receptors located mainly in the pharynx, larynx, trachea & large bronchi bifurcations are stimulated via mechanical, irritant or thermal mechanisms.
2. Neural impulses are then carried along afferent pathways of the vagal and superior laryngeal nerves, terminating at cough centre in medulla.
3. Efferent fibres of vagus and spinal nerves carry neural activity to muscles of the diaphragm, chest wall & abdomen.
4. These muscles contract
5. The glottis opens suddenly creating the cough.
Underlying Causes of Cough - Relative Incidence in Community Pharmacy
Most Likely: Viral Infection
Likely: Upper airway cough syndrome (formerly known as postnasal drip & includes allergies), acute bronchitis
Unlikely: Croup, Chronic bronchitis, Asthma, Pneumonia, ACE-Inhibitor induced
Very unlikely: Heart failure, Bronchiectasis, Tuberculosis, Cancer, Pneumothorax, Lung Abscess, Nocardiasis, GORD.
Questions to ask to gain information on a patient/ patients cough.
- Sputum Colour
- Nature of sputum
- Onset of cough
- Duration of cough
- Periodicity of cough
- Age of patient
- Smoking history
Sputum Colour
- Question to ask relating to patient cough & Relevance of answer.
Mucoid (clear/white) - Normally little consequence, suggests no infection is present.
Yellow/Green/Brown: Indicates infection; mucopurulent sputum is generally caused by a viral infection & dose not require automatic. referral.
Rust Coloured (Haemoptysis): Pneumonia
Pink Tinged: Left Ventricular failure
Dark Red: Carcinoma
Bright red blood: sputum with can occur as a single event due to the force of coughing causing blood vessel to rupture. This is not serious & required no automatic referral.
Nature of Sputum
- Question to ask relating to patient cough & Relevance of answer
Thin/Frothy: suggests left ventricular failure
Thick/Mucoid to yellow: can suggest Asthma
Offensive/foul smelling: suggests bronchiectasis or lung abscess.
Onset of Cough (time of day occurs)
- Question to ask relating to patients cough & Relevance of answer.
Cough worse in morning may suggest:
- Upper airway cough syndrome (previously termed post nasal drip)
- Bronchiectasis
- Chronic Bronchitis
Duration of Cough
- Question to ask relating to patients cough & Relevance of answer.
Coughs lasting >3 weeks should be viewed with caution.
- The longer a cough is present the more likely serious pathology is responsible.
E.g./
0-3 weeks: most likely upper respiratory tract infection causing (URTI)
> 3 weeks: likely acute or chronic bronchitis
3 months: conditions such as chronic bronchitis, GORD, Carcinoma become more likely.
Duration of Cough
- Question to ask relating to patients cough & Relevance of answer.
Acute Cough: can take 4 weeks or more to resolve.
Coughs lasting >3 weeks should be viewed with caution though.
- The longer a cough is present the more likely serious pathology is responsible.
Periodicity of Cough
- Question to ask relating to patients cough & Relevance of answer.
Recurrent cough in Adult: could be chronic bronchitis, especially if they smoke.
Recurrent cough in Child: if presents & family history of eczema/asthma/hayfever may suggest asthma - referral would be required for further investigation.
Age of Patient
- Question relating to patient with cough & relevance of answer.
Children: most likely will present with URTI, but asthma & Croup should be considered.
With Increasing age: conditions such as bronchitis, pneumonia & Carcinoma become more prevalent
Age of Patient
- Question relating to patient with cough & relevance of answer.
Children: most likely will present with URTI, but asthma & Croup should be considered.
With Increasing age: conditions such as bronchitis, pneumonia & Carcinoma become more prevalent
Smoking History
- Question Relating to patient with cough & Relevance of answer.
Smoker/
- More prone to chronic & recurrent coughs.
- Over time this might develop into chronic bronchitis & COPD
Clinical Features of Acute Viral Cough
- Most likely cause of cough presenting in community pharmacy
- Typically present with sudden onset & associated fever.
- Cold symptoms often present
- Sputum Production minimal
- Sputum can be mucopurulent (this does not always indicate bacterial cause, almost never does & referral should not be routine for this symptom as a result)
- Symptoms often worse in evening
- Usually last 7-10 days (>14 days indicates postural cough/possible secondary bacterial infection)
Clinical Features of Upper Airways Cough Syndrome (UACS).
- Umbrella term routinely used as Postnasal drip definition broadened to include rhinosinus conditions related to cough.
- May still sometimes be referred to as Postnasal drip or rhinosinusitis.
[Likely cause of cough presenting in community pharmacy]
Condition to eliminate
Characterised by sinus or nasal discharge, flowing behind nose into throat.
Creates an abnormal sensation in throat; may be described by patients feeling as though
- Have something stuck in throat,
- Swallowing mucus
- Having to clear throat more often.
Causes of Upper Airway Cough Syndrome (UACS)
- Umbrella term routinely used as Postnasal drip definition broadened to include rhinosinus conditions related to cough.
- May still sometimes be referred to as Postnasal drip or rhinosinusitis.
[Likely cause of cough presenting in community pharmacy]
Condition to eliminate
Chronic Cough: characteristically associated with UACS
Allergies: One cause of UACS.
- Coughs caused by such are often nonproductive & worse at night
- May show seasonal variation; e.g. hay fever
Vasomotor Rhinitis: caused by odours & changes in temperature
Post URTI Infection
Treatment of Upper Airway Cough Syndrome (UACS).
- Umbrella term routinely used as Postnasal drip definition broadened to include rhinosinus conditions related to cough.
- May still sometimes be referred to as Postnasal drip or rhinosinusitis.
[Likely cause of cough presenting in community pharmacy]
Condition to eliminate
Best to treat underlying cause of UACS rather than just treating the cough.
e.g. antihistamines, decongestants
Clinical Features of Acute Bronchitis
[Likely cause of cough presenting in community pharmacy]
Condition to eliminate
- Most often seen in autumn/winter
- Symptoms similar to URTI, but dyspnoea & wheeze tends to also be present.
- Usually last 7-10 days (can persist for 3 weeks)
Ateiology of Acute Bronchitis
[Likely cause of cough presenting in community pharmacy]
- Normally viral
- Sometimes bacterial.
Management of Acute Bronchitis
[Likely cause of cough presenting in community pharmacy]
- Symptoms will usually resolve without antibiotic treatment even if bacterial in nature.
- Refer if patients systemically unwell
Recurrent Viral Bronchitis**
- Most prevalent in preschool/young school-aged children.
- Most common cause of persistent cough in children of all ages
Aetiology of Laryngotracheobronchitis (Croup)
[Unlikely cause of cough presenting in community pharmacy]
- Parainfluenza Virus: recent infection with this virus accounts for 75% of all cases.
- Rhinovirus
- Respiratory Syncytial Virus
Clinical Features of Laryngotracheobronchitis (Croup)
[Unlikley cause of cough presenting in community pharmacy]
- Affects infants between 3 months & 6 years; incidence highest between 1-2 years of age.
- Affects 2-6% of children
- Slightly more common in boys than girls.
- More common in autumn & winter months
Symptoms;
- Occur in late evening/nigh; tend to improve during day and recur following night.
- Cough can be severe/violent; often described as barking (seal like).
- In-between coughing episodes child may be breathless/struggle to breathe properly.
- Usually symptoms resolve within 48 hours.
Management of Laryngotracheobronchitis (Croup)
[Unlikely casus of cough presenting in community pharmacy]
- Warm moist air is treatment used since 19th century; current guidelines don’t advocate for humidifier use though.
Referral or advisement to parents to seek medical intervention:
- >48 hour persistence
- Symptoms of stridor (noisy breathing occurring due to obstructed airflow through narrowed airway); oral/intramuscular dexamethasone or nebulised budesonide usually required if this present.
- Symptoms of distress
