Asthma Flashcards
What is asthma?
- People with asthma have sensitive and inflamed airways that become narrower than normal
- Symptoms include coughing, weezing, shortness of breath and chest tightness
- Symptoms of asthma tend to come and go depending on ‘triggers’
- Important to take medication even when you don’t have the symptoms
Reliever inhaler
Helps relieve asthma symptoms and attacks
- Relaxes the airways
- If asthma is well controlled shouldn’t need it more than three times a week
Preventer inhaler
Helps long term at reducing inflammation in the airways and less likely to narrow in response to triggers
Device test
Do this if inhaler hasn’t been used in more than 5 days
- Remove cap and shake inhaler well
- Point the mouthpiece away from you and press the canister to release a puff into the air
pMDI Inhaler technique
- Remove the cap
- Shake the inhaler well
- Sit or stand up and tilt your chin slightly - this helps medication reach lungs better
- Breathe out gently and slowly away from the inhaler
- Put your lips on the mouthpiece
- Start to breathe in slowly and steadily whilst pressing the canister
- Continue to breathe in slowly until lungs feel full
- Remove inhaler from mouth and seal your lips
- Hold your breath for 10 seconds or as long as you comfortably can
- Breathe out gently away from your inhaler
- If inhaler contains steroid, then rinse mouth to avoid side effects
- If you require a second dose then wait 30 seconds to a minute until you repeat the steps
Spacer inhaler technique
- Attach mouthpiece to spacer device
- Breathe out gently and slowly away from spacer
- Place your lips around spacer mouthpiece to create an effective seal
- Release one dose of the inhaler into the spacer device
- Breathe in and out deeply several times into the spacer device
Spacer care instructions
Wash with detergent once a month and leave to air dry
- Never wipe dry as it can cause static causing the drug to stick to the sides
- Replace every year
Pathophysiology of Asthma
- Excessive reaction from Type 2 helper cells
- Produce cytokines such as IL4 and IL5
- Smooth muscle spasm and increased mucuous production which narrows airways making it difficult to breathe
Newly diagnosed/suspected asthma
- SABA as reliever therapy (in some patients this may be the only therapy required)
- Inhaled corticosteroid low dose as preventer therapy
- If still not controlled, add leukotriene and if still not controlled add LABA with ICS
- Next step is to increase ICS dose to moderate
Beta adrenergics
SABA:
- Salbutamol, terbutaline
- Rapid onset of action - 15 mins
- Effects last up to 4 hours
- Four times daily use
LABA:
- Salmaterol
- Duration of action for 12 hours
- Start at low dose and monitor before increasing
Interact with corticosteroids, diuretics and xanthine derivatives to cause hypokalaemia
Interact with digoxin causing digoxin toxicity
Overall pneumonia management
IV Fluids
Oxygen
Chest physiotherapy
Analgesia
May require respiratory support
VTE prophylaxis
Cultures>Antibiotics
Community acquired pneumonia management
CURB 0-1 score
1st: Doxycycline PO
Alternative: Amoxicillin PO
CURB 2-5 score
1st: Benzylpenicillin IV + Doxycycline PO/Clarithyromycin IV\
Alternative: Levofloxacin IV/PO
Hospital acquired pneumonia management
1st: Doxycycline PO
Severe: Benzylpenicillin IV + Gentamicin IV
Alternative: Levofloxacin IV/PO
Aspiration pneumonia
1st: Doxycycline PO + Metronidazole PO
Severe: Benzylpenicillin IV + Metronidazole IV
Alternative: Levofloxacin IV + Metronidazole IV
FEV1:FVC
FEV1 is the forced expiration volume in 1 second
FVC is the maximum amount of air out
If FEV1:FVC ratio is lower than 0.7 then this is an indicator
Mechanism of action of Beta adrenergics
Beta 2 receptor is coupled to G protein which gets activated which in turn activated adenylate cyclase
Initiates ATP conversion to cAMP causing phosphorylation of myosin light chain kinase inhibiting its activity.
Phosphotase enzyme predominates leading to bronchiole smooth muscle relaxation
Side effects of beta adrenergics
Tremor/nervousness/anxiety/excitement
Increased heart rate
Headache
Nausea and vomiting
Stuffy nose, coughs
Side effects of beta adrenergics
Nervousness/anxiety/excitement
Tremors
Increased heart rate
Headaches
Nausea and vomiting
Stuffy nose, coughs
Mechanism of action of inhaled corticosteroids
Have anti-inflammatory effects (glucocorticoids)
- Not to be used during asthma attack as they do not provide immediate relief
They bind to steroid receptors, which bind to DNA to induce synthesis of specific mRNA
- Reducing formation of cytokines
- Inhibiting prostaglandin synthesis
- Reducing eosinophil influx into lungs
Side effects of ICS
- Cough
- Sore throat
- Difficulty speaking
- Bronchoconstriction
- Oropharyngeal Candidiasis
Mechanism of action of leukotriene receptor antagonists
Bind to leukotriene receptors on bronchial smooth muscles to block smooth muscle contraction, reduce mucus production and preventing blood vessel permeability
- Have slower onset of action so cannot be used during an acute attack
Side effects of LTRA
- Headache
- GI disturbances
- Fatigue
- Urticaria
Mechanism of muscarinic antagonist
Blocks effects of Acetylcholinesterase which binds to muscarinic receptors
