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Flashcards in Respiratory Deck (20)
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Salbutamol: Indications

Asthma: SABA or LABA w. corticosteroid


Salbutamol: Mechanism of Action

GPCR mediated smooth muscle relaxation
Also stimulate Na+/K+ ATPase so shift K+ to intracellular compartment


Salbutamol: Adverse Effects

Relate to stimulation of B receptors in other systems: palpitations, tachycardia, anxiety, tremor
Can also cause hyperglycaemia and muscle cramps


Salbutamol: Warnings and Interactions

LABA alone is associated with an increase in asthma deaths
Take care in patients with CVD, due to the risk of tachycardia and arrhythmia
Can reduce the effectiveness of B agonists


Salbutamol: Prescription

SABA inhaled as needed
Given by nebuliser acutely
LABA used twice daily in combination inhaler e.g. symbicort
Monitoring by serial PEFR measurement
Check inhaler technique


Anti-Muscarinics (ipatropium, tiotropium): Indications

COPD (short acting e.g. tipatropium as needed, long acting e.g. ipatropium for prevention)


Anti-Muscarinics (ipatropium, tiotropium): Mechansim of Action

Competitively inhibit ACh so reduce parasympathetic tone. This causes smooth muscle relaxation and a reduction in glandular secretions


Anti-Muscarinics (ipatropium, tiotropium): Adverse Effects

Very few as there is little systemic absorption
Can cause dry mouth


Anti-Muscarinics (ipatropium, tiotropium): Warnings and Interactions

Can cause a risk in intraocular pressure so could affect closed angle glaucoma
Caution in patients at risk of arrhythmia
In practice, they can usually be inhaled by these patients with few issues
Interactions not generally an issue as they are inhaled


Anti-Muscarinics (ipatropium, tiotropium): Prescription

Inhaler or nebuliser (for acute treatment)
LAMA once daily
Advise about dry mouth: chew gum, suck sweets
Check inhaler technique
Monitor symptoms and PEFR measurements in asthmatics


Corticosteroids, inhaled (beclometasone, budesonide): Indications

Asthma (Step 2 treatment)


Corticosteroids, inhaled (beclometasone, budesonide): Mechanism of Action

They are steroids, so the pass through the cell membrane and act on nuclear receptors. They alter the transcription of a variety of genes related to inflammation. Interleukins, cytokines and chemokine are down regulates, and anti-inflammatory proteins are up regulates. This reduces mucosal inflammation and mucus secretion and widens the airway.


Corticosteroids, inhaled (beclometasone, budesonide): Adverse Effects

Local effects: Immunosuppression, so candida infection can occur. Hoarse voice,
Systemic (rare, only at high doses because of low systemic absorption): adrenal suppression, growth retardation, osteoporosis.


Corticosteroids, inhaled (beclometasone, budesonide): Warnings and Interactoins

Caution in children (growth suppression) and COPD patients with a history of pneumonia
They have no clinically significant interactions


Corticosteroids, inhaled (beclometasone, budesonide): Prescription

Usually twice daily by inhaler
Inhaler technique should be taught and assessed.
Monitored by symptoms, and PEFR in asthma


Oxygen: Indications

Increase tissue oxygen delivery in hyperaemia
Speed up reabsorption of gas in pneumothorax
Reduce half life of carboxyhemoglobin in CO poisoning


Oxygen: Mechanism of Action

Increased PaO2
Decreased alveolar N2 concentration, to pleural gas is reabsorbed and breathed out quicker
Competes with CO to bind to Hb


Oxygen: Adverse Effects

Discomfort from mask
Dry throat


Oxygen: Warnings and Interactions

Patients with chronic T2 respiratory failure and CO2 retention (e.g. COPD) may experience respiratory depression if the O2 saturation gets too high
It should not be exposed to heat of flame as it accelerates combustion


Oxygen: Prescription

Monitor by spO2 and ABG measurements
Target 94 to 98% in healthy people
Target 88 to 92% in COPD