Case 7 SAP Flashcards
Describe the management of anaphylaxis
Assess ABCDE. If anaphylaxis suspected, give 0.5ml IM adrenaline. If no change after 5 minutes, give a repeat dose of adrenaline. Keep reassessing ABCDE.
What effects does giving adrenaline have on anaphylaxis?
Relieves airway obstruction from mucosal oedema (alpha 1), inotropic and chronotropic effects relieve hypotension and shock (beta 1), relieves bronchoconstriction and decreases mediator release (beta 2)
What can also be given for anaphylaxis?
O2 for hypoxia, IV fluids for hypotension and shock, inhalers for bronchospasm, nebulised adrenaline for laryngeal oedema.
What is given for bronchospasm/obstruction in COPD?
β2 agonists (SABA and LABA), methylxanthines (theophylline), selective PDE4 inhibitor roflumilast, cholinergic antagonists (LAMA)
Describe the COPD treatment pathway
1st: stop smoking, vaccines, pulmonary rehabilitation if needed, self-management plan, treatment for comorbidities
2nd: start inhaled therapies (SABA or SAMA) if 1st line complete, needed to relieve breathlessness, and patient has been trained to use inhalers
3rd: offer LABA and LAMA if exacerbations despite treatment and no asthma/steroid responsiveness OR consider LABA + ICS if asthmatic features or steroid responsiveness
4th: consider LABA + LAMA + ICS
Describe the asthma treatment pathway
1st: low dose ICS with a SABA
2nd: low dose ICS, LTRA with a SABA
3rd: low dose ICS, LABA with or without LTRA with a SABA
4th: low dose ICS plus a LABA within a MART regimen, with or without LRTA
5th: moderate dose ICS plus LABA
6th: high dose ICS plus LABA and SABA
7th: moderate ICS with trial of additional drug with SABA and LABA
8th: send to asthma expert
Describe acute bronchitis
a lower respiratory tract infection which causes inflammation in the bronchial airways. Annual incidence 44 per 1000 adult population. Most episodes occur during autumn or winter. Avoid cigarette smoke, chemicals, dust, and air pollution to help prevent. Most are viral but can be bacterial.
Describe pneumonia
an infection of the lung tissue in which the air sacs in the lungs become filled with microorganisms, fluid, and inflammatory cells, affecting the function of the lungs. Defined as the presence of clinical signs and symptoms along with radiological changes that are consistent with pneumonia. 220,000 diagnosed annually, incidence of community-acquired pneumonia (CAP) is 5-10 per 1000 adult population. Can be prevented by immunization, adequate nutrition, and by addressing environmental factors.
Most common causes of CAP
streptococcus pneumoniae (gram positive rod), haemophilus influenzae (gram negative bacilli or coccobacilli), and staphylococcus aureus (gram positive cocci) are the most common causative agents of CAP. Strep is the most common cause, haemophilus is common in people with COPD, and staph is common in people with recent influenza diagnosis or severe illness.
Signs and symptoms of pneumonia
acute illness, fever, cough, mucopurulent sputum, haemoptysis, breathlessness, pleuritic pain, abnormal chest x-ray, confusion in the elderly, crackles, and bronchial breathing. May get rust coloured sputum with strep pneumoniae.
Risk factors for pneumonia
aged over 65, living in a residential home, COPD, exposure to cigarette smoke, alcohol misuse, antacids, and contact with children.
List the atypical pneumonias
mycoplasma pneumoniae and legionella species (gram negative bacilli).
Describe hospital acquired pneumonia
similar symptoms to CAP. Defined as new onset cough with purulent sputum in patients who are beyond two days after initial admission. Significant mortality risk in elderly with co-morbidities.
Describe diagnosis of pneumonia
clinical judgement as no combination of signs or symptoms is clearly diagnostic, cough is predominant symptom, chest x-ray required to confirm (normal for bronchitis, abnormal for pneumonia). Sputum culture, blood culture, and test to identify the bacterium. Can also test for antigens in urine (strep, legionella), antibodies in the blood (staph a), ELISA/PCR/IgM antibodies detection (M pneumoniae).
Scoring system for pneumonia
CURB65 score (confusion <8, plasma urea >7, resp rate >30, BP <90/<60, aged >65). Score of 0-1 = outpatient, 2 = admit to hospital, 3 = ICU.
Treatment of pneumonia
often wide spectrum given until causative agent identified. Give amoxicillin for 0 – 2 CURB65 CAP, give co-amoxiclav for 3 – 5. First choice HAP is co-amoxiclav as mild and low risk of resistance.
List the endemic fungi causing respiratory tract infections
histoplasma capsulatum (causes histoplasmosis, mid-central and eastern half of USA, found in bat and bird faeces), coccidioides immitis (causes coccidioidomycosis, central and South America, found in soil), and Paracoccidioides brasiliensis (causes Paracoccidioidomycosis, central and South America, water borne). All generally have no/mild symptoms.
List the opportunistic fungi
candida (causing candidiasis), mucor species (causing mucormycosis), cryptococcus neoformans (causing cryptococcosis), and aspergillus species (causing aspergillosis).
Describe aspergillosis
localised pulmonary infection in people with underlying lung disease, allergic broncho-pulmonary disease, allergic sinusitis, and allergic alveolitis. Can cause necrotising inflammation, oedema, bleeding, and formation of granulomas. Caused by inhaling mould from soil, compost, rotting leaves, plants, trees, crops, dust, damp building, and air conditioning systems.
Who do fungal infections typically infect?
especially problematic in the immunocompromised. About 15% of HIV patients admitted to hospital in the UK will suffer a nosocomial pulmonary infection and 5-10% of these will be opportunistic fungal pneumonias.
How are fungal pneumonias treated?
antifungal drugs (ending in -azole), but in advanced cases surgical debridement may be necessary – the removal of dead, damaged, or infected tissue.
List the common viral causes of RTIs
adenoviruses, rhinoviruses, coronaviruses, paramyxoviruses (RSV and human para-influenza viruses), and orthomyxoviruses (influenza A, B, and C).
Describe HPIV
important cause in children, four well recognised types HPIV1-4, spread as rhinovirus, mostly causing mild disease with symptoms including malaise, fever, cough, and sore throat.
Describe symptoms of influenza
abrupt onset, shivering, malaise, headache, aching limbs and back, high fever approx. 39C – many symptoms could be the result of the cytokine storm released by infected cells.
Treatment and prevention of influenza
Treatment: neuraminidase inhibitors (Tamiflu/oseltamivir and Relenza/zanmivir) but use is controversial and for high-risk groups. Prevention: hand hygiene, inactivated vaccine containing range of H and N subunits that is reformulated at intervals to match prevalent strains.
Describe the types of influenza
three types defined by serology of internal matrix protein and nucleoprotein. A – epidemics and pandemics, infect animals and humans, designated based on the antigenic relationship of external spike proteins e.g. H1N1, H5N1. H1 – H17 = haemagglutinin, N1 – N9 = neuraminidase. B – milder epidemics. C – normally mild disease in children.
Describe avian flu H5N1
has been spreading among poultry and wild birds for 25 years and recently started spreading to mammals. 868 human infections with 457 deaths – no human-human transmissibility yet so calls to start vaccine development.
Describe the environmental impact of MDIs
puffer type inhalers that mix the medicine with a gas in the canister. The gas is HFC (hydrofluorocarbon) and is a potent greenhouse gas that contributes to global warming. They have up to a 30x greater carbon footprint than DPIs and are overused in the UK. If MDI is necessary, then ensure using the lowest puff : strength ratio (e.g. 1 puff of 200mcg rather than 2 puffs of 100mcg).
Describe inhaler recycling
even when inhaler has run out of medicine it continues to leak harmful propellant into the atmosphere. Instead of putting the empty inhaler in the bin, bring back to a local pharmacy that will either recycle it or will dispose of it via waste medicine management.
Describe the implications of poorly controlled asthma
carbon footprint up to 8 times higher. Overuse of SABA if poorly controlled which can lead to increased propellant use (MDI) and increased plastic waste (both MDI and DPI). Requires more appointments so the carbon footprint of the appointment increases (e.g. driving to the appointment). Increased risk of hospitalisation, especially acute care, which is more resource intense and generates a large carbon footprint. More likely to need additional medication including antibiotics which increases plastic waste and can contribute to antibiotic resistance.
Short-term impact of air pollution on lung disease
rapid onset of symptoms, including irritated airways, feeling out of breath, and coughing. High levels of pollution can also cause an asthma attack or COPD exacerbation.
Long-term impact of air pollution on lung disease
can contribute to the development of some lung conditions including lung cancer and asthma. Estimated that air pollution contributes to up to 36,000 early deaths in the UK every year.
Occupational links to asthma
: healthcare, agricultural, food plant workers, carpenters, and chemical industry workers are more at risk for work-related asthma. Most are caused by repeated, long-term exposure but a severe, single exposure to a hazardous agents can damage the lung – most are preventable. Agents include allergens, antibiotics, latex, proteolytic enzymes, platinum salts, acid anhydrides and polyamine hardening agents.
Exercise and cold air with asthma
Physical exercise and cold air –> increased ventilation –> increased mouth ventilation –> respiratory induced water loss –> increased extracellular osmolarity –> influx of intracellular calcium –> activation of phospholipases –> mast cell degranulation –> exercise induced asthma. Wheeze afterwards, epithelial lining fluid of the bronchi becomes hyperosmolar.
Allergen exposure with asthma
allergen exposure can lead to immediate asthma (reaches max in 15-20 minutes and subsides in 1 hour) or can be late-phase reaction with a more prolonged and sustained attack – can be for several weeks after the exposure.
Drugs in causing
asthma
NSAIDs trigger asthma in approx. 5%. Beta blockers can lead to bronchoconstriction and airflow limitation in asthmatics.
Describe mycoplasma pneumoniae
M pneumoniae (walking pneumonia) is one of the smallest known free living organisms and lacks a rigid cell wall (so no gram stain). Transmission comes from airborne droplets through close contact. Frequently mild and self-resolving, common in children and teenager
Describe legionella
Legionella caused by inhalation of contaminated aerosols. Presence associated with cooling towers, air conditioning units, fountains, hot tubs, and shower heads
Symptoms of rhinoviruses
nasal congestion, sneezing, cough, sore throat, rarely fever
Describe transmission of rhinoviruses
respiratory route, hand to mouth, and contaminated surfaces. 2-3 day incubation period, optimum growth temperature 33C
Describe the rhinovirus type
non-enveloped RNA
approx 100 serological types
cause approx 80% common colds
Describe the adenovirus type
non-enveloped DNA
51 known serotypes
7 species A-G
Describe the adenovirus type
non-enveloped DNA
51 known serotypes
7 species A-G
cause approx 5-10% RTIs
Symptoms of adenoviruses
cold-like, pharyngitis, bronchitis, pneumonia, diarrhoea, fever, conjunctivitis, acute respiratory disease
death is rare but infections can be problematic in immunocompromised people
Describe the spread of adenoviruses
commonly cause outbreaks in crowded environments (so new military recruits are vaccinated)
respiratory route, hand to mouth, contaminated surfaces, close personal contact, faecal/oral
RSV virus type
paramyxovirus, enveloped, ssRNA (positive sense)
Epidemiology of RSV
most common cause of bronchitis in infants
approx 20,000 hospital admissions of infants per year in UK
Symptoms of RSV
similar to common cold in most cases, 25-40% <1 year old show signs of bronchiolitis or pneumonia
may cause death in elderly or immunocompromised
Spread of RSV
droplets. re-infection common, incubation period of roughly 5 days. hand hygiene important to prevent.
What is given to infants susceptible to RSV?
Palivizumab (monoclonal anitbody)
Influenza virus types
orthomyxoviruses
enveloped negative RNA with segmented genomes
Neuraminidase
enzyme on surface of influenza, antigenic and aids release from infected cells
Haemagglutinin
influenza antigenic glycoprotein that binds to target cell receptors
Transmission and replication of influenza
respiratory route
2-3 day incubation period
replicated in epithelial cells of respiratory tract so cilia are destroyed
generally short-lived but can be dangerous for at-risk groups
Describe human coronaviruses
enveloped ssRNA
mild infections - malaise, nasal discharge, no fever/cough, rarely sore throat
3 day incubation
3 other coronaviruses known to cause severe disease
MERS-CoV, SARs-CoV, SARs-CoV-2
bats or mammals may be natural hosts
Symptoms of SARs-CoV-2
Fever, new and continuous cough, SOB, fatigue, loss of appetite, loss of smell, and loss of taste. Other, less common symptoms include headache, muscle pain, sore throat, nasal congestion, chest pain, nausea and vomiting, diarrhoea, and skin rashes especially in younger people
Nirmatrelivir
Anti-viral for coronaviruses. 3C-like protease inhibitor
Ritonavir
Anti-viral for coronaviruses. Inhibits the metabolism of protease inhibitors
Remdesivir
Anti-viral for coronaviruses. Terminates RNA transcription
Molnupiravir
Anti-viral for coronaviruses. Inhibits RNA polymerase
Non-anti-viral treatments for coronaviruses
Tocilizumab (monoclonal antibody) and dexamethasone (corticosteroid)
Which bacteria cause hospital acquired pneumonia?
Caused by gram negative rods (E. coli, klebsiella species, pseudomonas species, Acinetobacter baumanii), anaerobic bacteria (Enterobacter), and strep pneumoniae.
