Respiratory (Misc) Flashcards
(43 cards)
types of smoking cessation therapy
nicotine replacement therapy (NRT), varenicline, or bupropion
how should pharmacological therapy be used to aid smoking cessation
- Should be given to patient on or before a particular target stop date
- prescription should only last util 2 weeks after the target stop date (2 weeks NRT or 3/4 weeks of varenicline/bupropion)
- ## if treatment is unsuccessful do not offer a repeat within 6 months unless special circumstances have contributed to failure
nicotine replacement therapy modes
gum, patches, lozenges and nasal sprays
nicotine replacement therapy contraindications
Cautions
* Cardiovascular disease and peripheral arterial disease
* Diabetes mellitus
* Hyperthyroidism
* Renal/hepatic impairment
* Peptic ulcers
Contraindications
- Severe cardiovascular disease (e.g. arrhythmia, post-myocardial infarction, recent stroke or TIA)
adverse effect of NRT
- Dizziness
- Nausea
- Myalgia and flu-like symptoms
- Palpitations
- Dyspepsia
MOA OF VARENICLINE
Varenicline is an alpha-4 beta-2 nicotinic acetylcholine receptor partial agonist. It blocks and stimulates the receptor leading to reduced craving. It also inhibits the pleasure derived from smoking.
varenicline contraindication
Cautions
- History of psychiatric illness – can increase risk of suicidal thoughts/behaviour
- Breastfeeding
- Severe renal impairment
- Withdrawal symptoms on stopping – gradual withdrawal may need to be considered
Contraindications
- Pregnancy
- <18 years
varenicline adverse effects
Nausea
Headaches
Insomnia
Abnormal dreams
bupropion
Bupropion is an atypical antidepressant that has been demonstrated in trials to be effective in smoking cessation.
It is a noradrenaline and dopamine reuptake inhibitor and nicotinic antagonist.
contraindications of bupropion
Cautions
- There is a risk of seizures (1 in 1000)
- Hepatic cirrhosis
- Renal impairment
- Blood pressure
Contraindications
- Patients with a history of seizures
- Pregnancy
- Bipolar disorder
- <18 years
bupropion adverse effects
Adverse effects
Seizures (1 in 1000)
Insomnia
Dry mouth
Smoking and Pregnancy
- Pregnant people should be offered carbon monoxide testing at all antenatal appointments to assess exposure to tobacco smoke – this is because it can be difficult to disclose smoking during pregnancy due to the stigma surrounding it
Management
* Refer to stop-smoking support (e.g. NHS Stop Smoking)
* Consider nicotine replacement therapy
* Varenicline and bupropion are contraindicated
MOA of CO poisoning
Carbon monoxide binds to haemoglobin more strongly, forming carboxyhaemoglobin, leading to tissue hypoxia. Carboxyhaemoglobin can take several hours to dissociate, meaning blood cannot carry as much oxygen in this timeframe.
Sources of Carbon Monoxide
- Poorly-maintained housing (e.g. blocked chimneys, lack of ventilation, gas ovens)
- Smoke in burning buildings
- Aerosols
- Running petrol/diesel engines in confined spaces, even if the windows are open
presentation of CO poisoning
Questions to ask can be remembered using the mnemonic COMA:
- Cohabitees – is anyone else in the property affected? – including pets
- Outdoors – do the symptoms improve outside the building?
- Maintenance – are any fuel-burning appliances and vents properly maintained?
- Alarm – does the house have a carbon monoxide alarm?
Features seen in carbon monoxide poisoning are non-specific, making it difficult to diagnose:
- Headaches – most common:
- Often described as tension-type headaches
- Nausea and vomiting
- Vertigo
- Altered consciousness
- Confusion
- Fatigue
- Non-specific pain – usually the chest or stomach
- Weakness
Features of severe CO toxicity may be:
- Pink skin and mucosae
- Personality changes
- Arrhythmia
- Parkinsonism
- Coma
- Death
- Classic ‘cherry red’ skin is rarely seen in life and is usually seen post-mortem
CO investigations
REMEMBER: Pulse oximetry may be falsely normal – it cannot differentiate oxyhaemoglobin and carboxyhaemoglobin
Venous or arterial blood gas – gold standard:
- Shows increased carboxyhaemoglobin levels:
- <3% is normal for non-smokers
- <10% is normal for smokers
- > 30% indicates severe exposure
Serum lactate:
May be elevated in severe poisoning
ECG:
- May show cardiac ischaemia or arrhythmia
Serum troponin:
- May show cardiac ischaemia
Serum glucose:
Always test in any patient with reduced consciousness
management of carbon monoxide poisoning
- 1st-line: 100% high-flow O2 via non-rebreather mask
- Evidence suggests that this reduces the half-life of carboxyhaemoglobin
- Evidence surrounding hyperbaric oxygen is controversial
- Any patient who has suffered smoke inhalation should be assumed to have carbon monoxide poisoning and should also be treated as such
complications include: myocardial infarction
causes of pulmonary embolism
thrombus
fat
gas
aminionic fluid
RF pulmonary embolism
- Up to 30-50% have no identifiable cause (unprovoked)
- Deep vein thrombosis (DVT)
- Previous VTE
- Active cancer
- Recent surgery (within the last 2 months), especially major orthopaedic surgery
- Significant immobility (e.g. hospitalisation or bed rest >5 days)
- Lower limb paralysis, trauma, or fracture
- Pregnancy and the postpartum period
- > 60 years of age
- Combined oral contraceptive use
- Obesity
- Long-distance sedentary travel (e.g. long-haul flights)
- Varicose veins
- Superficial venous thrombosis
- Any cause of hypercoagulable state (e.g. factor V Leiden, antiphospholipid syndrome)
- Behçet’s disease
- Nephrotic syndrome (due to loss of antithrombin III and plasminogen in urine)
presentation of PE
There is a classic triad of dyspnoea, haemoptysis, and pleuritic chest pain, however in reality this only presents in around 10% of patients.
- Dyspnoea – most common presenting complaint (usually acute)
- Pleuritic chest pain (usually acute)
- Tachycardia
- Tachypnoea
- Signs of a DVT:
- Usually pain and swelling in one leg (or both), and there may be redness, warmth, and distended veins
- Presence of risk factors in the history
- Cough
- Fever
- Haemoptysis – present in around 8% of patients
if a patient with a PE is haemodynamically unstable…
suggests a massive pulmonary embolism and usually requires critical care.
- Tachycardia
- Hypotension
- Acute right ventricular dysfunction (e.g. elevated jugular venous pressure)
- Syncope or pre-syncope
Pulmonary em bolism rule-out criteria (PERC)
The PERC rule can be used to rule out a PE when the suspicion of diagnosis is relatively low, but reassurance is desired. The PERC is negative when none of the criteria are present, making the probability of a PE is <2%. A score >0 (i.e. if any feature is present) is a positive PERC.
If the suspicion of a PE is higher, the PERC should be skipped and a 2-level PE Wells score should be calculated.
Two-level PE Wells score
If a PE is suspected, then a Two-level PE Wells score should be calculated. A PE is likely if there are >4 points and unlikely if there ≤4 points.
