Upper Respiratory Tract Infections Flashcards
What are the 2 main functions of the URT?
To conduct air from outside of the body to the lower respiratory tract - filters warms and humidifies the air through the nasal cavity.
Has a defence mechanism to protect the body from irritating substances.
What is the pharynx/throat?
Tube-like structure which connects the back of the nasal cavity to the larynx and oesophagus.
In order to help the air and food go into the correct passageway, pharynx contains a specialised flap-like structure called epiglottis – lowers over the larynx to prevent the inhalation of food and liquid into the oral respiratory tract.
What is the larynx?
This is the passage for air and contains vocal cords essential for human speech. Larynx is small and triangular in shape and it extends from the epiglottis down to the trachea and helps control the movement of epiglottis. Larynx also has specialised muscular folds that close off, preventing food, foreign object or secretions such as saliva from entering the lower respiratory tract.
What is the trachea/windpipe?
Tube extending from the larynx into the bronchi, carrying air from larynx right into lungs. Trachea lines with ciliated cells which push particles out and cartilage rings which reinforce the trachea and preventing collapsing during breathing.
What is rebound congestion?
Rhinitis/congestion is worsening of congestion caused by medication on withdrawal.
What is (Rhino) sinusitis?
Inflammation of the mucosal lining of the paranasal sinuses and excess mucus during sinus infection.
(Rhinitis = inflammation of nasal mucosa - continuous rhinitis = sinusitis)
What is acute sinusitis?
Sinusitis which completely resolves within 12 weeks.
What is chronic sinusitis?
Sinusitis which causes symptoms which last more than 12 weeks.
What is the definition of acute sinusitis?
An increase in symptoms after 5 days or persistence of symptoms beyond 10 days.
What are the symptoms of acute sinusitis in children?
Nasal blockage or congestion.
Discoloured nasal discharge.
Cough during the day/night/
What are the symptoms of acute sinusitis in adults?
Nasal blockage/congestion.
Nasal discharge.
Dental or facial pain/pressure.
Reduction/loss of sense of smell.
What are 3 symptoms of rhinitis if it is caused by bacteria?
Discoloured or purulent nasal discharge.
Severe localised unilateral pain.
Fever.
FeverPAIN score classification.
Fever in last 24 hours Purulence Attend rapidly under 3 days Inflamed tonsils No cough or coryzal (inflammation of mucous membranes on nose)
Centor score/TTHA classification.
Tonsillar exudate
Tender anterior cervical lymphadenopathy
History of fever
Absence of cough
What is a cough?
A reflex stimulated by irritation of mucosa of th respiratory tract.
What is the main function of a cough?
Airway clearance.
Why is the cough reflex initiated?
Due to excess mucus in airways or secretions, dust, particles or cold/hot air which irritates the trachea and sets off the cough reflex.
What are the clinical feature of acute cough?
Sudden onset. Associated cold symptoms may be present. Minimal sputum production. Worse in the evening. Associated fever.
Describe the cough reflex.
Physical or chemical stimulation of irritant receptors in the larynx, trachea or bronchial tree or inflammation in these sites results in a forceful expiratory blast which can remove inhaled material.
What are the 5 defence mechanisms of the URT?
- mucocilliary lining
- lymphatic tissue in the tonsils and adenoids
- smell and non-olfactory detection
- cough reflex
- normal flora organisms
What is the role of normal flora organisms?
- these compete with pathogens for attachment sites on the mucocilliary lining.
- can produce bactericidal substances such as toxins or acids.
What conditions must be met for a respiratory disease to be established (4)?
- Sufficient dose of infectious agent inhaled.
- Infectious particles must be airborne.
- Infectious organism must remain alive and viable while in the air.
- Organism must be deposited on susceptible tissue in the host.
List some URT infections.
Cough, otitis media, croup, common cold, sinusitis, sore throat.
What virus is the common cold caused by?
Mainly rhinovirus
Describe the steps for the pathogenesis of the common cold.
- Virus is acquired by direct contact/transmission of particles.
- Virus attaches to and infects the cells lining nasal region and pharynx.
- Virus then sheds coat, releases nucleic acids and replicates.
- Macrophages release cytokines as part of body’s innate and adaptive immune response.
- This causes inflammation in the respiratory tract - dilate blood vessels and stimulate nerve cells causing congestion and sneezing.
- The ciliated columnar epithelial cells are destroyed and slough off.
- Destruction reaches peak by day 2-5.
- Regeneration of cells occurs with new cells formed by day 14.
What are secondary pathogens?
Pathogens which easily enter the body due to the weakening of the immune system brought about by the original pathogen.
Give an example of an oral decongestant and describe this.
Pseudoephedrine
- no immediate effect
- no rebound congestion on withdrawal
- adverse drugs reactions - sympathomimetic effects
- caution groups
Give examples of topical decongestant and describe this.
Topical = nasal
Ephedrine, Oxymetazoline, Xylometazoline
- immediate effect
- prolonged use can result in rebound congestion on withdrawal
From what age should decongestants be given?
From over 6 only
Oral decongestants should be avoided in what groups?
- Those taking monoamine oxidase inhibitors (MAOIs) due to possibility of hypertensive crisis.
- Diabetics, hypertension, hyperthyroidism, glaucoma, prostatic hypertrophy, hepatic/renal impairment, ischaemic heart disease.
Describe sinuses.
- membrane lines air spaces within the skull located near the nose.
- frontal sinuses are above the nose on either sides.
- maxillary sinuses are under the cheekbone.
- ethmoid and sphenoid sinuses are located near the eye sockets.
What causes (Rhino) sinusitis?
Bacterial - streptococcus pneumoniae
Viral - main cause initially by rhinovirus
Fungal - rare, found in immunocompromised individuals
What are the symptoms of sinusitis if caused by bacteria?
- symptoms for more than 10 days.
- discoloured/purulent nasal discharge.
- severe localised unilateral pain (one on side).
- fever
- marked deterioration after initial milder phase.
What does NICE recommend on antimicrobial prescribing if sinusitis symptoms have lasted more than 10 days with no improvemnt?
Consider no antibiotic or backup antibiotic depending on cause.
Consider prescribing high-dose nasal corticosteroid for 14 days for adults and children 12+ e.g. mometasone 200mg bd.
- use backup antibiotic if symptoms worsen or don’t improve after 7 days.
What antibiotic/s do the NI care guidelines recommend as 1st line for adults with sinusitis?
Phenoxymethylpenicillin
500mg QDS for 5 days
What antibiotic/s do the NI care guidelines recommend as 2nd line for adults with sinusitis?
Doxycycline
200mg the first day only then 100mg
100mg OD for 5 days
Clarithromycin
500mg BD for 5 days
What antibiotic/s do the NI care guidelines recommend as 1st line for pregnant women with sinusitis?
Erythromycin
250-500mg QDS for 5 days
What antibiotic/s do the NI care guidelines recommend as treatment for high risk adults with severe sinusitis?
Co-amoxiclav 500/125mg
TDS for 5 days
Antibiotics for child with sinusitis is age dependent. Check notes.
…………………………………………………………
List some viral sore throat symptoms.
- red swollen tonsils
- throat redness
- hoarse voice sometimes
- high temperature
- headache
- tiredness
- cough
- earache
List some bacterial sore throat symptoms.
- elevated fever especially in streptococci
- exudates on pharynx/ tonsils
- grey furry tongue
- throat redness
- swollen uvula
- red swollen tonsils
- absence of cough
- anterior neck lymphadenopathy - swollen necks glands
What do the scores of the FeverPAIN score mean?
0-1 = 13-18% streptococci
2-3 = 34-40% streptococci
4 or above = 62-65% streptococci`
What do the scores of the Centor score mean?
0-2 = 3-17% streptococci 3-4 = 32-56% streptococci
When is an immediate antibiotic given?
- if systemically very unwell
- has signs/symptoms of a more serious illness/condition
- has high risk of complications
- if high FeverPAIN score
Describe the clinical features of an acute cough.
- sudden onset
- associated with fever
- minimal sputum production
- worse in the evening
- associated cold symptoms can be present
Cough can be classified as productive and non-productive. Describe the difference between them.
Productive
- presence of excess secretions = mucus
- usually is second phase associated with common cold
Non-productive
- stimulation of cough centre with no excess secretions produced
- initial cough associated with common cold
What can be given to manage an acute productive cough?
- Expectorants e.g. guaifenesin = will expectorate mucus, secretions and excess phlegm.
- Honey or pelargonium (rec by NICE).
What can be given to manage an acute non-productive cough?
- Antitussives/cough suppressants = pholcodine or dextromethorphan (rec by NICE).
- Demulcents (soothing substances) = honey or pelargonium or glycerin.
What can chronic cough be caused by?
Usually is secondary to something else.
- GORD - acid reflux
- Asthma - poor controlled
- Drug induced - side effect/ADR (ACE inh can cause dry coughs)
- Smoking - bronchitis, COPD etc
Which cough and cold meds are no longer suitable for under 6s according to MHRA 2009?
- Antihistamines: chlorphenamine, promethazine, brompheniramine
- Antitussives: pholcodine, dextromethorphan
- Expectorants: guaifenesin, ipecacuanha
- Decongestants: pseudoephedrine, ephedrine, oxymetazoline, xylometazoline
Why honey cannot be given to children under 12 months?
Risk of botulism = rare and fatal - toxin produced by bacterium.
Describe croup.
Viral infection caused by parainfluenza virus.
It’s an infection in the upper airways which obstructs the airways causing respiratory distress.
Barking cough - stridor.
May have fever.
Cough worse at night.
Prodromal symptoms (sym between incubation and disease).
Affects mainly child 6m-3y
How is croup managed in moderate-severe cases?
Admit to hospital.
Give single oral dose of dexmethasone - 15mg/kg.
What to do if croup affected breathing?
Urgently referred to secondary care.
Nebulised adrenaline.
Oxygen.
Intubation if required.
What is whooping cough?
URT caused by Bordetella Pertussis.
Highly contagious - spread by droplet transmission.
Initial symptoms like common cold.
Coughing ep lasts a few mins.
Brings up thick mucus and vomiting due to high intensity of cough.
Cough more common at night.
How is whooping cough managed?
Best prevented through immunisation: - at 8, 12 and 16 weeks - at 3 years 4 months - during pregnancy Treatment may be macrolide antibiotic, tests, rest, fluids.
Describe what acute otitis media is.
It is the infection of the middle ear.
Characterised by ear ache that may be severe.
Bulging tympanic membrane and effusion (fluid accumulation).
Preceded by URT symptoms such as cough.
Recurrent.
What can cause otitis media?
Bacterial or viral.
What are the risk factors for otitis media?
Young age Contact with other children Use of formula milk instead of breast milk Use of dummy Passive smoking
List systemic systems associated with otitis media.
Not systemic but loss of hearing due to effusion
Pain, fever, loss of appetite, loss of sleep, N & V.
How is otitis media diagnosed?
By otoscopic appearance.
- bulging tympanic membrane
- changes in membrane colour
- perforated tympanic membrane with discharge of pus
When should antibiotics be prescribed?
SELECTIVE PRESCRIBING
- Child under 2 with bilateral AOM.
- Systemic symptoms including high temp or vomiting.
- Local signs of severe infection - bulging tympanic membrane.
- High risk patient.
- Duration of 4 days and no improvement.
What antibiotic/s do the NI care guidelines recommend as 1st line for adults with otitis media?
Amoxicillin
500mg TDS for 5 days
What antibiotic/s do the NI care guidelines recommend as 2nd line for adults with sinusitis?
Clarithromycin
500mg BD for 5 days
