W7 Respiratory Infections Flashcards
What are some examples of respiratory infections?
- Covid 19
- Infective exacerbation of COPD
- Tuberculosis (TB)
- Empyema
- Pleurisy
- Influenza
- Acute bronchitis Bronchiectasis
- Pneumonia
- Community acquired
- Hospital acquired
- Aspiration pneumonia
What is pneumonia by definition?
What are the 3 types
Definition:
* Inflammation of the lungs caused by a bacterial or viral infection, in which the air sacs fill with pus and can become solid.
* 2019 – affected 489 million people worldwide
* Most common population groups:
* Children <5 years
* Adults >70 - highest mortality
* Can affect either:
* BOTH lungs → double/bilateral pneumonia
* ONE lung → single / unilateral pneumonia
* Pneumonia can be split into three categories:
1) Community acquired pneumonia (CAP)
2) Hospital acquired pneumonia (HAP)
3) Aspiration pneumonia
What is community acquired pneumonia?
What are the risk factors?
What are the most and least causative organisms?
- Caused by overgrowth of pathogenic bacteria in the upper respiratory tract leading to infection
- The bacteria responsible for the infection will depend on local epidemiology
- The severity of the infection will depend on:
- The invading organism and its response to antimicrobial treatment
- Patients underlying co-morbidities
- Presence of risk factors
- Age >65
- PMHx of COPD
- Exposure to cigarette smoke (active or passive smoker)
- Housed in residential / care home
- Alcohol abuse
- Use of acid-reducing drugs - stomach acid, allows pathogens to colonise upper resp.
tract more easily (GIS ISU) - Weaker risk factors: chronic renal disease, chronic kidney
Most common causative organisms
Streptococcus pneumoniae
Influenza viruses (viral CAP)
Less common causative organisms
Haemophilus influenzae
Staphylococcus aureus (inc MRSA)
Group A streptococci
Legionella spp **
** most common in immunocomprom pts
What are the symptoms of Influenza? (8)
Fatigue, low energy levels
Fever/chills
Severe coughing / sore throat – yellow/green sputum or bloody mucus
SOB / rapid breathing (High respiratory rate)
Chest pain
Nausea and vomiting
Muscle aches/ pains
Confusion
How can you diagnose CAP?
tests?
observations?
Diagnosis & Assessment:
* Thorough history from the patient – including HxPC / symptoms
Blood tests:
* CRP
* WCC
- Patient observations:
- Blood pressure
- Heart rate
- Respiratory rate
- Temp
- Oxygen saturation
Chest X-ray: shows new signs of consolidation
* Within 4 hours of presentation
* Within 1 hour if suspecting seps
What is the differential diagnosis of CAP? (7)
- Covid 19 associate CAP – treatments differ
- Acute bronchitis
- Infective exacerbation of COPD
- Tuberculosis
- Empyema
- Lung cancer
- Pulmonary embolism (PE
CAP Treatment:
What is the criteria used to diagnose a patient?
C U R B - 6 5 (Hospital)
C R B – 6 5 (Primary care)
Confusion
Urea >7.0 mmol/L
Resps >30/min
Blood pressure *Low systolic <90 mmHg and <60mmHg
65- Age >65
CURB 65 0-1 low severity:
Treatment?
Amoxicillin PO 500mg TDS for 5 days
OR Pen allergic:
1. Doxycycline PO 200mg STAT, 100mg OD for 5 days
2. Clarithromycin PO 500mg BD x5days
CAP- Amoxicillin
Antibiotic class: Penicillin
* Side effects:
* Hypersensitivity; rash and anaphylaxis
* 1 – 10% of individuals exposed = reaction
* 0.05% of reactions = anaphylaxis
* Patients with atopic conditions more prone to anaphylactic reactions
* Cross sensitivity with cephalosporins
* Diarrhoea = Abx associated colitis
* Nausea and vomiting
* Contra indications: allergy (anaphylaxis)
* Cautions: Hx of allergy (inc. rash)
* Counselling:
* Can cause diarrhoea – seek advice if this becomes severe
* Diarrhoea is not an allergy – common s/e
CAP- Doxycycline
- Antibiotic class: tetracycline
- Side effects:
- Angioedema (swelling –eyes, lips, tongue, hands)
- Diarrhoea
- Oesophageal irritation
- Photosensitivity - skin
- Teeth discolouration (avoided in children)
- Hepatic disorders
- inc intracranial hypertension: headache and visual disturbance
- Contra indications: children <12 years
- Cautions: myasthenia gravis ( muscle weakness)
- Counselling:
- Take with food
- Swallow whole
- inc skin sensitivity to sunlight – advise on SPF use, sunbed avoidance
- Avoid calcium and aluminium containing products when taking = bind to the Abx rendering it ineffective. Take 2 hours before / 4 hours after
CAP- Clarithromycin:
Clarithromycin
* Antibiotic class: Macrolide
* Side effects:
* appetite inc. altered taste
* GI discomfort – diarrhoea, nausea, vomiting,
burping
* Hearing impairment
* Dry mouth
* QT interval prolongation
* Cautions: when used with other QT prolonging drugs
!! REMINDER !!
Clarithromycin is an enzyme
INHIBITOR interaction potential
CAP
What treatment is used for patients with Curb score 2 (moderate severity)?
Non-pen allergic
Amoxicillin (PO) 500mg – 1000mg TDS
5 days
PLUS Clarithromycin (PO) 500mg BD
Pen allergic: Doxycycline (PO) 200mg STAT, 100mg OD PLUS Clarithromycin (PO) 500mg BD x5 days
What treatment is used for patients with Curb score 3 or above (high severity)?
Non-pen allergic:
Co-amoxiclav (PO / IV) PO – 625mg TDS or I V – 1.2g TDS x5 days
Pen allergic:
Clarithromycin (PO / IV) 500mg BD
OR
Levofloxacin (PO / IV) 500mg BD
x5 days
- Unlikely you will see the use of co-amoxiclav for CAP in hospital setting, unless advised by microbiology consultant or for
very specific indications - Why?
- High risk of clostridium difficile infective diarrhoea often associated with the excess use of broad spectrum antibiotics
- High resistance rates beginning to develop
- Within SBUHB & HDUHB 1st line for CAP, CURB-3
- Amoxacillin (IV) 1g TDS plus
- Clarithromycin (PO/IV) 500mg BD
CAP- Co-amoxiclav
- Antibiotic class: Penicillin (amoxicillin + clavulanic acid)
- Side effects:
- As per amoxicillin
- Hepatic disorders: ALT, AST (liver enzymes)
- Contra indications: Hx of jaundice due to co-amoxiclav
administration - Monitoring:
- Liver function (in pts with known liver disease)
- Notes: allergy potential
CAP- Levofloxacin
Side effects?
- Antibiotic class: Quinolone
- Side effects:
- GI upset - dec appetite, constipation, diarrhoea, N&V
- QT prolongation
- Affect glucose control
- Photosensitivity reactions
- Eye disorders / discomfort
- Headache
- Convulsions
- Tendon damage
- Serious musclo-skeletal and nervous system disorders
Specific MHRA safety alerts released
CAP- Levofloxacin
What are the MHRA warnings?
1) Can induce convulsions (with/without Hx of seizures)
2) Tendon damage
* C/I in patients with Hx of quinolone induced tendon
damage
* Patients >60 at an increased risk
* Risk increased when used with corticosteroids
* Stop immediately is tendonitis suspected
1) INC risk of aortic aneurysm / dissection
2) INC risk of disabling, long lasting or irreversible adverse reactions affecting the musclo-skeletal and nervous system
* Patients should be provided with MHRA advice sheet outlining s/e to lookout for
Levofloxacin:
Cautions?
C/I?
Counselling?
Monitoring?
Cautions:
* Patients with QT prolongation risk factors
* Use in children – arthritis in weight bearing joints
* Patients >60 – s/e risk
* Patients with renal impairment - s/e risk
* Disorders that pre-dispose patient to seizures:
-Epilepsy
-Alcohol dependence
- Contra indications:
- Hx of quinolone induced tendon damage
- Counselling:
- Provide MHRA advice leaflet
- Look out for signs / symptoms of tendonitis e.g. muscle or tendon pain, swelling
- Monitoring:
- Signs of s/e – discuss with the patient
- Renal function
CAP counselling?
- Patient expectation in terms of symptom resolution should be addressed
- Symptom should improve steadily but the rate of improvement will vary depending on the severity of the pneumonia
- Symptoms resolution timeline:
- 1 week: fever should have resolved
- 4 weeks: chest pain and sputum production should have substantially reduced
- 6 weeks: cough and breathlessness should have substantially reduced
- 3 months: most symptoms should have resolved but fatigue may still be present
- 6 months: most people will feel back to normal
Hospital acquired pneumonia (HAP) -
BACTERIAL
What are the risk factors?
- HAP vs CAP
- Symptoms occur >48 hours after hospital admission
- Symptoms differ slightly to CAP – less specific
- Treatments differs as infection likely to be cause by different organisms (hospital acquired):
-Pseudomonas aeruginosa
-Escherichia coli
-Klebsiella pneumoniae
Risk factors
* Poor infection control/hand hygiene – hence why this is so important in clinical settings
* Head of bed at <30° angle
* Intubation and mechanical ventilation
* Acid- medications (PPIs or H2 antagonists)
HAP Symptoms?
Cough
Dyspnoea (shortness of breath)
Inc Resp rate
Confusion
Increase in lung secretions
Increased oxygen requirement
Fever/chills
Leukocytosis (high WCC) or Leukopenia (low WCC)
How to diagnose HAP?
What symptoms can deem it as severe?
Chest X-Ray –signs of new significant lung
infiltration PLUS
Either…
* Fever >38°
* WCC >11
PLUS
Any of the following:
* Inc resp secretions
* SOB
* Cough
* resp rate
* impaired oxygenation
* New confusion
- Unlike CAP – there isn’t a severity scoring tool that can be used to help guide treatment.
- Severity of condition determined by patients clinical status e.g. deemed SEVERE if they have any of the following symptoms:
- New confusion (other causes should also be considered)
- Respiratory rate > 30/min
- Bilateral or multiple infiltrates on Chest X-Ray
- Severe sepsis and sepsis shock
- Multi organ dysfunction
- Acute (new) Respiratory failure (PaO2 < 8 kPa and/or PaCO2 > 6.0 kPa)
- Requiring critical care support
What are the non-severe treatments for HAP?
Non-pen allergy:
Co-amoxiclav (PO) 625mg TDS
5 days
Pen allergy: Doxycycline (PO) 200mg STAT, 100mg OD OR
Co-trimoxazole (PO) 960mg BD OR
Levofloxacin (PO) 500mg OD - BD
Co-trimoxazole (BRAND: Septrin) in treating non-severe HAP:
Combination antibiotic: Sulfamethoxazole + trimethoprim
* Dosing:
* CrCL > 30 ml/min: 960mg BD
* CrCL < 30 ml /min: 480mg BD
* Side effects:
* Hypersensitivity; rash and anaphylaxis
* Diarrhoea = Abx associated colitis
* Blood disorders: Dec Hb, Dec PLT, Dec leucocytes
Contra indications: allergy to co-trimoxazole (or
trimethoprim or sulfonamides)
* Cautions:
* Blood disorders
* Risk of hyperkalaemia
* Elderly = increased risk of s/e
* Monitoring:
* Renal function – affects dosing, avoid if CrCL < 15
* Blood counts – especially in prolonged treatment
What are the treatments for Severe HAP?
Non-pen allergy:
Tazocin (IV) 4.5g TDS x5 days
Pen allergy: (non-severe)
Meropenem (IV) 1g TDS
Pen allergy:
(severe) Levoflaxacin (IV) 500mg OD - BD
Tazocin (Piperacillin & Tazobactam in treating severe HAP
Antibiotic class: Penicillin
* Dosing:
* CrCL > 20 ml/min: 4.5g TDS
* CrCL < 20 ml /min: 4.5g BD
* Side effects:
* Hypersensitivity; rash and anaphylaxis
* Diarrhoea Abx associated colitis
* Nausea and vomiting
* Anaemia
* Contra indications: allergy (anaphylaxis)
* Cautions: Hx of allergy (inc. rash)
* Monitoring:
* Sodium levels – high levels of Na in each vial
* Renal function
* Bowel motions – broad spec Abx so C.Diff risk
Meropenem (IV) in treating severe HAP
Antibiotic class: Carbapenems
Dose:
* CrCL >50 ml/min: 500mg – 1g TDS
* CrCL 26 – 50 ml/min: 500mg – 1g BD
* CrCL 10 – 25 ml/min: 250 – 500mg BD
Side effects:
* Diarrhoea
* Skin reactions rash
* Contra indications:
* Severe penicillin allergy
* Monitoring:
* Liver function tests – risks of hepatotoxicity
* Allergy / cross sensitivity
* Cross sensitivity between carbapenems and penicillin’s
* Hence, contraindicated in patients with severe penicillin allergy (anaphylaxis, angioedema)
What is COPD by definition?
What are the symptoms? (5)
Definition:
Chronic obstructive pulmonary disease is a progressive disease of the lungs
that is characterised by airflow limitation that are not fully reversible
Symptoms
* Increased shortness of breath – progressive & gets worse over time
* Chronic or recurrent cough
* Regular sputum production
* Wheeze
* Frequent chest infections
What is an exacerbation?
What causes and exacerbation?
Sustained worsening of symptoms from the persons stable state (beyond their normal day-
to-day variation) which is acute in onset
- There are certain triggers that can cause an exacerbation
- These triggers may not always cause an infection and so antibiotics are not always needed. Triggers include:
- Viral infections
- Smoking
- Environmental pollution
- Bacteria ** - only trigger which will respond to antibiotics
Exacerbation symptoms and diagnosis of COPD
Symptoms:
* Increase in the patients usual breathlessness or SOB
* Increased cough
* Changes to “normal” sputum production:
* Colour: green / yellow suggestive of infection
* Volume and viscosity (thickness) of mucus increased
* Less typical symptoms:
* Increased wheeze / chest tightness
* Reduced exercise tolerance
* Increased fatigue
* Acute confusion
Exacerbation symptoms and diagnosis
Diagnosis
* Thorough Hx from a patient to
establish whether they have a
PMHx of COPD
* Thorough Hx of their
symptoms have worsened
(with an acute onset)
* Trigger identification
What is the differential diagnosis for HAP?
- Pneumonia = consolidation on chest X-Ray
- Pulmonary embolism = blood clot on the lung
- Heart failure
- Pneumothorax = collapsed lung
- Pleural effusion = fluid in lung
Treatment – infective exacerbation
- For an infective exacerbation of COPD (IECOPD) – Antibiotics may need to be prescribed
- Consider antibiotics for patients with an acute exacerbation of COPD but only after considering:
- Symptom severity: are they worse / are there changes to the patients normal symptoms?
- Sputum colour – green/yellow suggestive bacterial infection
- Thickness and volume of sputum
- Does the patient need hospitalisation?
- Breathlessness severe
- Significant co-morbidities
- Oxygen saturation <90%
- Confusion or conscious level affected
- Previous exacerbation history and risk of the patient developing complications
- Previous sputum cultures and the results what antibiotics were the previous infecting bacteria susceptible to?
- Antimicrobial resistance patterns within the area and previous antibiotic use
What is the treatment choice for IECOPD?
1st and 2nd choice
- Amoxicillin (PO) 500mg TDS
- Doxycycline (PO) 200mg stat, then 100mg OD
- Clarithromycin (PO) 500mg BD
x 5 days
What is the treatment choice for IECOPD?
Alternative choice – patients at risk of
treatment failure
What does this mean?
Co-amoxiclav (PO) 625mg TDS
5 days
Co-trimoxazole (PO) 960mg BD
Levofloxacin (PO) 500mg OD
