Respiratory Flashcards
What are the routes of administration for respiratory drugs?
via:
inhalation
Oral
IV
What are the types of delivery aids that can be used to deliver respiratory drugs?
Inhalers - Meter dose inhaler (MDI), Breath activated device (spinhaler, turbohaler)
Spacers - Medication ejected into chamber before inhalation
What is ventilation?
Movement of air between the environment and the lungs via inhalation and exhalation
What drugs are used in ventilation to improve airway patency?
Bronchodilators
Anti-inflammatory
Anti-cholinergic drugs
Which drugs are used to prevent mast cell degranulation?
Mast cell stabilisers - Chromoglycate - stops mast cells releasing inflammatory mediators such as histamine (inhaled) - YELLOW/WHITE inhaler
Leukotriene receptor agonists - montelukast - good for mast cell disorders but not as potent as steroids (oral route - tablets)
What drugs are used to impair ventilation?
Beta blockers - blocks adrenaline which normally acts as a bronchodilator, however when blocked it can manifest in asthmatic symptoms
Respiratory depressants
- Benzodiazepenes (Diazepam) - act on GABA receptors
- Opioids (Morphine) - pain relief
What bronchodilators are used as respiratory drugs and how do they work?
B2 agonists:
Short acting - Salbutamol/Terbutaline (BLUE) onset 2-3 mins, lasts 4-6 hours, for bronchial constriction (all routes)
Long acting - Salmeterol (GREEN) onset 1-2 hours, lasts 12-15hrs, used to prevent bronchial constriction, always used with an inhaled steroid e.g. Seretide (PURPLE) which is Fluticasone and salmeterol
What antiinflammatories are used as respiratory drugs and how do they work?
corticosteroids - reduce inflammation in bronchial walls (effective topical or systemic)
- Beclomethasone (BROWN)
- Budesonide (BROWN)
- Flucitasone (ORANGE)
- Mometasone (PINK)
What anticholinergics are used as respiratory drugs and how do they work?
Anticholinergics - inhibit muscarinic ACh receptors in autonomic nerves, basal tone only = increase bronchial dilation, decrease Mucus secretion e.g. Ipratropium (inhaled route) (GREEN/WHITE)
What drugs are used to improve gas exchange?
Respiratory stimulants such as
Theophyllines - postive chronotropic (^HR), positive inotropic (^contractility), bronchodilator, therefore better gas exchanging properties due to better air exposure in alveoli and blood flow
- Cause - Diuresis, arrythmia, CNS stimulation
Oxygen - is a drug and should be treated as such
What are the signs and symptoms of Obstructive Airways Disease?
Symptoms:
- Cough (Dry? sputum and if so what colour? Blood?)
- Wheeze - expiratory noise
- Stridor - Inspiratory noise
- Dyspnoea - distress on effort to breathe
- Pain - generic, or upon inspiration (pleuritic pain)
Signs:
- Resp rate - 12-15/min
- Symmetry of air entry/chest expansion
- Percussion note - resonant/dull
- Vocal resonance
What are the investigations for obstructive airways disease?
- Sputum examination
- Chest radiograph
- Pulmonary function - PEFR (maximum flow rate), FEV1 (forced expiratory volume - vol of exhaled air in 1 second), FEV1/FVC - FEV1/total amount of air exhaled in fev test (vital capacity)
- Bronchoscopy
- VQ scan
(ventilation/perfusion mismatch)
What are the main differences between obstructive and restrictive lung disease?
Obstructive characterised by reduction in AIRFLOW, so shortness of breath –> in exhaling air, whereas restrictive is reduction in LUNG VOLUME so difficulty in taking air into the lung.
In obstructive disorders the air will remain inside the lung after full expiration, whereas restrictive disorders occur due to stiffness inside the lung tissue or chest wall cavity
Obstructive disorders - COPD, Asthma, Bronchiecstasis
Restrictive disorders - Interstitial lung disease, scoliosis, neuromuscular cause, marked obesity
What are three types of respiratory infections?
Pneumonia - Strep pneumoniae causes inflammation (pneumonitis) of the alveoli and they become fluid filled (consolidation) preventing oxygen exchange
Legionairre’s disease - Leigonella pneumophilia causes an atypical pneumonia often transmitted by stagnant water dental chair
Tuberculosis (TB) - Mycobacterium Tuberculosis - only 10% of cases symptomatic, if so cough, fever and weight loss
What is Asthma and what are the signs/symptoms?
Reversible airflow obstruction - Bronchial hyper-reactivity
Triad of:
- Airway smooth muscle constriction
- Inflammation of mucosa
- Increased mucus secretion
Diurnal process -worse in the morning
- Cough, wheeze, shortness of breath
- Triggered by infections, environmental stimuli (dust, smoke, chemicals), cold air
Atopy - genetic predisposition to allergy
- Mast cell degranulation (IgE released - primary allergen antibody)
- Eosinophils, T cells, interleukins activated
- B2 agonists, Chromoglycate, steroids prevent mast cells degranulating