BNF - Chapter 2 - Cardiovascular System (Part 1) Flashcards
What is an arrhythmia?
It is a condition which the heart beats with an irregular or abnormal rhythm
Just give a quick summary of how the heart works?
- the sinoatrial node (SA) sends electrical impulses from the atrium causing it to contract and pump blood into the ventricles through a ‘junction box’ called the AV node.
- The impulses spreads into the ventricles, causing the muscle to contract and to pump out the blood.
What are ectopic heart beats?
- They are changes in a heartbeat that is otherwise normal.
- These changes lead to extra or skipped heartbeats
If ectopic beats are spontaneous and the patient has a normal heart is treatment required?
No treatment is rarely required and reassurance to the patient will often suffice.
If ectopic beats are troublesome which drug class may be used?
- Beta-blockers are sometimes effective and may be safer than other suppressant drugs
What is Atrial Fibrillation (AF)?
- In AF, electrical impulses do not originate in the SA node, but form a different part of the atrium or nearby pulmonary veins.
- These abnormal impulses become rapid and disorganised radiating through the atrial walls in an uncoordinated manner.
- This can cause the walls of the atria to fibrillate (quiver rapidly) rather than contracting normally.
In AF why is there a risk of a blood clot(s) to form?
During AF, because the atria do not contract regularly, blood does not empty efficiently into the ventricles and begins to pool in the atria.. which can cause clots to form.
- If the blood clot become dislodged, they can travel to the brain causing a stroke.
What is the treatment aims of AF?
To prevent stroke and VTE.
How can AF be managed?
By controlling ventricular rate (‘rate control’) or attempting to restore and maintain sinus rhythm (‘rhythm control’).
What should all patients with AF be assessed for?
Their risk of stroke and thromboembolism.
What is the first line treatment for AF?
- Rate control is preferred first line option using a BETA BLOCKER (not sotalol) or
- Rate-limiting CALCIUM CHANNEL BLOCKER (e.g. DIltiazem or Verapamil)
For treatment of AF if a single drug fails to control ventricular rate what may be used secondline?
- A combination of two drugs (beta blocker, Digoxin or Diltiazem) can be used
For AF as third line option (rhythm control) which drugs can be used to achieve this?
- Beta-blocker
- but if beta-clocker is ineffective or not tolerated, an oral anti-arrhythmic drug such as SOTALOL, FLECAINIDE or AMIODARONE can be used.
How long within should a referral be made if at any stage AF treatment fails to control symptoms?
Within 4 weeks
How often should patients with AF be reviewed for anticoagulation, stroke and bleeding risk?
At least annually
What should all patients with life-threatening haemodynamic instability caused by new-onset atrial fibrillation undergo?
- Electrical Cardioversion without delaying to achieve anticoagulation.
In patients presenting acutely but without life-threatening haemodynamic instability what can be offered if the onset of arrhythmia is less than 48 hours?
- Rate or rhythm control can be offered
If onset is more than 48 hours or uncertain then what is preferred?
- Rate control is preferred.
If pharmacological cardioversion (not electrical cardioversion) has been agreed for AF which drug can be used?
- Intravenous Amiodarone hydrochloride
What is an alternative to IV Amiodarone?
- Flecainide Acetate
When is IV Amiodarone preferred over flacainide?
- if there is a structural heart disease
For AF if urgent rate control is required which drug(s) IV can be used?
- A beta blocker or verapamil hydrochloride can be given intravenously.
Which two ways can sinus rhythm be restored?
- Electrical cardioversion
- Pharmacological cardioversion (with an oral or intravenous antiarrhythmic drug e.g. flecainide acetate or amiodarone hydrochloride).
If atrial fibrillation has been present for more than 48 hours is electrical or pharmacological cardioversion preferred?
- Electrical cardioversion is preferred and should not be attempted until the patient has been fully anticoagulated for at least 3 weeks.
- If this is not possible, parenteral anticoagulation should be commenced and a left atrial thrombus ruled out immediately before cardioversion
Oral anticoagulation should be given after cardioversion - how long should this be continued for?
For atleast 4 weeks.
Prior to cardioversion, what should be offered as appropriate?
- Offer rate control
When is digoxin only effective for controlling ventricular rate?
- Only good at controlling rate at rest, and should therefore only be used as monotherapy in predominantly sedentary patients with non-paroxysmal atrial fibrillation.
If ventricular function is diminished which combination of drugs is preferred?
- Beta-blocker (that is licensed for use in heart failure) and Digoxin is preferred.
Digoxin is also used when atrial fibrillation is accompanied by what?
When AF is accompanied by congestive heart failure.
To increase success of electrical cardioversion, and to maintain sinus rhythm when should amiodarone be initiated and for how long?
start it 4 weeks before and continue for up to 12 months after electrical cardioversion
When should Flecainide acetate or propafenone not be given when treating AF?
- These should not be given if there is known ischaemic or structural disease.
In patients with left ventricular impairment or heart failure which drug should be considered?
- Amiodarone
What is paroxysmal atrial fibrillation?
A type of atrial fibrillation where episodes come and go and usually stop within 48 hours without any treatment.
In symptomatic paroxysmal atrial fibrillation how is ventricular rhythm controlled?
1) with a standard beta-blocker
2) If symptoms persist or standard beta blocker is not appropriate then an oral anti-arrhythmic drug such as dronedarone, sotalol, flecainide, propafenone or amiodarone can be given.
In selected patients with infrequent episodes of symptomatic paroxysmal atrial fibrillation can they self-treat an episode of AF when it occurs?
Yes - to restore sinus rhythm the ‘pill-in-the-pocket’ approach can be used
- involves patient taking oral flecainide or propafenone
Which tool is used to assess the risk of stroke?
CHA2D-VASc assessment tool
Which tool is used to assess the risk of bleeding prior to and during anticoagulation?
HAS-BLED tool
What parameters are included in CHA2D-VASc score?
- Prior ischaemic stroke
- Transient ischaemic attacks
- Thromboembolic events
- Heart failure
- Left ventricular systolic dysfunction
- vascular disease
- Diabetes
- Hypertension
- Females
- Patients over 65 years
What is considered a low risk score of CHA2D-VASc tool?
- 0 for men
1 - for women
= low risk score and do not require an antithrombotic for stroke prevention
Which formulation of anticoagulation should be given to those with new onset atrial fibrillation who are receiving sub-therapeutic or no anticoagulation therapy?
Parenteral Anticoagulation
- Until assessment is made and appropriate anticoagulation is started
In AF, which anticoagulants are used?
May use:
- A vitamin K antagonist (Warfarin)
- or in non-valvular AF you can use apixaban, dabigatran, etexilate, edoxaban or rivaroxaban
Is Aspirin or Warfarin more effective at preventing emboli?
Aspirin is less effective at preventing emboli
Can aspirin be given as monotherapy solely for stroke prevention in AF?
No
If anticoagulant treatment is contraindicated or not tolerated what may be considered?
- Left atrial appendage occlusion can be considered.
What is recommended for paroxysmal supraventricular tachycardia?
- it will often terminate spotaneously
- OR with reflex vagal stimulation such as Valsalva manoeuvre, immersing the face in ice-cold water, or carotid sinus massage - such manoeuvres should be performed with ECCG monitoring
If effects of reflex vagal stimulation are transient or ineffective, then what may be given?
Intravenous adenosine
If adenosine is ineffective or contraindicated then what may be given?
Intravenous verapamil is an alternative - but this should be avoided in patients recently treated with beta-blockers
For Bradycardia (arrhythmia after MI) which drug should be given IV?
- Atropine sulfate - the dose may be repeated if necessary
- If there is a risk of asystole, or if the patient is unstable and has failed to respond to atropine sulfate, adrenaline/epinephrine should be given by intravenous infusion, and the dose adjusted according to response.
What do pulseless ventricular tachycardia or ventricular fibrillation require?
Requires resuscitation
For ventricular tachycardia which drug is the one of choice for restoring sinus rhythm?
- Amiodarone
- If sinus rhythm is not restored, direct current cardioversion or pacing should be considered.
What is Tosade de pointes?
It is a form of ventricular tachycardia and it is associated with a long QT syndrome (usually drug-induced)
What are the other factors of torsade de pointes?
- hypokalaemia
- severe bradycardia
- genetic predisposition
Is torsade de pointes self-limiting?
Episodes are usually self-limiting, but are frequently recurrent and can cause impairment or loss of consciousness
- if not controlled the arrhythmia can progress to ventricular fibrillation and sometimes death.
Can anti-arrhythmic be used for torsade de pointes?
No as they can further prolong the QT interval
What drug treatment is used for torsade de pointes?
- Magnesium sulfate is usually effective
- A beta-blocker (but not sotalol) and atrial (or ventricular) pacing can be considered
What can anti-arrhythmic drugs be classed according to?
They can be classified in those that they act on
- Supraventricular arrhythmias (occur in the area above the ventricles) (e.g. verapamil)
- Both Supraventricular and ventricular arrhythmias (Amiodarone)
- Ventricular arrhythmias (Lidocaine)
What can anti-arrhythmic drugs also be classed according to?
- Can be classed according to their effects on the electrical behaviour of myocardial cells during activity (the Vaughan William classification) although this classification is of less clinical significance
What are the four classes of the Vaughan Williams Classification?
Class I - membrane stabilising drugs e.g. lidocaine
Class II - Beta-blockers
Class III - Amiodarone; sotalol (also Class II)
Class IV - Calcium-channel blockers (includes verapamil but not dihydropyridines)
If two or more anti-arrhythmic drugs drugs are used why is special care needed?
The negative inotropic effects (weakening the heart’s contractions and slow the heart rate) of anti-arrhythmic drugs tend to be additive
What effect does hypokalaemia have on drugs regarding arrhythmia?
- Hypokalaemia enhances the arrhythmogenic (pro-arrhythmic) effect of many drugs.
What is the usual treatment for paroxysmal supraventricular tachycardia?
- Adenosine
Why is adenosine usually the choice of drug?
It has a vert short duration of action (half life only about 8-10 seconds, but prolonged in those taking dipyridamole)
- most side effects are short-lived
Can adenosine be sued after a beta-blocker?
- Yes unlike verapamil
Can adenosine be used in patients with asthma?
Verapamil may be preferable to adenosine in asthma
Which cardiac glycoside can be used to slow the ventricular response in cases of atrial fibrillation and atrial flutter?
Digoxin
Is intravenous infusion of digoxin effective for rapid control of ventricular rate?
- No it is rarely effective
Which types of arrhythmias are cardiac glycosides (digoxin) contraindicated in?
Arrhythmias associated with accessory conducting pathways (e.g. Wolff-Parkinson-White Syndrome)
What is Wolff-Parkinson-White syndrome?
In Wolff-Parkinson-White (WPW) syndrome, an extra electrical pathway between your heart’s upper and lower chambers causes a rapid heartbeat.
Which drug is effective for supraventricular tachycardias?
- Verapamil
- IV dose followed by oral dose
With high doses of verapamil what may occur?
Hypotension
Which arryhthmias should Verapamil not be used for?
Tachyarrhythmias where the QRS complex is wide (i.e. broad complex) unless a supraventricular origin has been established beyond reasonable doubt.
Similar to digoxin which type of arrhythmias is verapamil CI in?
- in AF or Atrial flutter associated with accessory conducting pathways (e.g. Wolff-Parkinson-White syndrome).
Which IV beta blockers can be used to achieve rapid control of the ventricular rate?
- Esmolol
- Propranolol
Which drugs work for both supraventricular and ventricular arrhythmias?
- Amiodarone
- Beta blockers
- Disopyramide
- Flecainide
- Procainamide (available from ‘special-order’)
- Propafenone
Which drug can be used for tachyarrhythmias associated with Wolff-Parkinson- White Syndrome?
- Amiodarone can be used
(but Digoxin and verapamil are Contraindicated)
Should only be initiated only under hospital or specialist supervision.
What is the advantage of using Amiodarone?
- It can be given IV as well as by mouth
- Has the advantage of causing little or no myocardial depression
Does amiodarone have a long or short half life?
- a very long half life (extending to several weeks) and only needs to be given once (but high doses cause nausea unless divided)
How long may it take to reach steady state plasma amiodarone concentrations?
- Weeks or months (this is important when drug interactions are likely)
What does Disopyramide impair?
Impairs cardiac contractility
What additional effect does Disopyramide have which may limit the use in patients?
it has an antimuscarinic effect which limits its use in patients susceptible to angle-closure glaucoma or with prostatic hyperplasia.
Flecainide is in the same general class as which drug?
- Lidocaine
And can be sued for serious symptomatic ventricular arrhythmias
What is propafenone used for?
is used for the prophylaxis and treatment of ventricular arrhythmias and also for some supraventricular arrhythmias. It has complex mechanisms of action, including weak beta-blocking activity (therefore caution is needed in obstructive airways disease—contra-indicated if severe).
In summary which drugs are used for supraventricular arrhythmias?
- adenosine
- cardiac glycosides
- verapamil hydrochloride.
In summary which drug is used in ventricular arrhythmias?
- Lidocaine
- Mexiletine is used in life threatening ventricular arrhythmias
In summary which drugs are used in both supraventricular and ventricular arrythmias?
- Amiodarone
- beta-blockers
- Disopyramide
- Flecainide
- Procainamide
- Propafenone
Can disopyramide be used for both ventricular and supraventricular arrhythmias?
Yes including after myocardial infarction, maintenance of sinus rhythm after cardioversion
Is Disopyramide an antiarrhythmic drug?
Yes
What Antiarrhythmic class is Disopyramide?
- Class IA
Give an example of Antiarrhythmic class IB?
- Lidocaine hydrochloride
What type of arrhythmias is lidocaine used for?
- Ventricular arrhythmias
Give an example of Antiarrhythmic class IC?
Flecainide Acetate
What type of arrhythmias is flecainide acetate licensed for?
- Supraventricular arrhythmias and ventricular arrhythmias
When flecainide is used concurrently with amiodarone what dose reduction does the manufacturer recommend?
Reduce the dose by half
What is the indication of propafenone hydrochloride?
- Ventricular arrhythmias
- Paroxysmal supraventricular tachy arrhythmias which include paroxysmal atrial flutter or fibrillation and paroxysmal re-entrant tachycardia involving the AD node or accessory pathway
Which class of antiarrhythmics does amiodarone belong to?
Class III
What is the usual dosing of amiodarone by mouth?
By mouth - 200mg three times a day for one week, then reduced to 200mg twice daily for a further week,, followed by maintenance dose, usually 200mg daily or the minimum dose required to control arrhythmia
What is the usual dose of amiodarone by IV?
Initially 5mg/kg, to be given over 20-120 minutes with ECG monitoring, subsequent infusions given if necessary according to response, maximum 1.2g per day
Is Dronedarone an antiarrhythmic drug?
Yes it is a multi-channel blocker anti-arrhythmic drug
What is the indication of dronedarone?
Maintenance of sinus rhythm after cardioversion in clinically stable patients with paroxysmal or persistent atrial fibrillation, when alternative treatments are unsuitable
What toxcity can dronedarone cause?
Pulmonary toxicity - Interstitial lung disease, pneumonitis and pulmonary fibrosis reported. Investigate if symptoms such as dyspnoea or dry cough develop and discontinue if confirmed.
Which eGFR range should dronedarone be avoided in?
- Avoid if eGFR less than 30ml/minute/1.73m2
Name two other drugs (antiarrhythmics) that can be used for rapid reversion to sinus rhythm?
- Adenosine
- Vernakalant
How does Vernakalant work?
Vernakalant is an anti-arrhythmic drug that blocks potassium and sodium channels in the atria, thereby restoring normal heart rhythm
Which Beta-blocker is used for antiarrhythmic purposes?
Sotalol
Is sotalol lipid or water-soluble and selective or non-selective?
Sotalol is water-soluble and non-selective
What important safety information is provided in the BNF for sotalol?
- Sotalol may prolong QT interval, and it occasionally causes life-threatening ventricular arrhythmias
- Manufacturer advises particular care is required to avoid hypokalemia in patients taking sotalol - electrolyte disturbances, particularly hypokalemia and hypomagnesaemia should be corrected before sotalol started and during use
IF the range of QT interval exceeds a certain amount then the manufacturer advises to reduce the dose of sotalol or discontinue. What QT interval range is this?
If QT interval exceeds 550msec.
Is amiodarone considered a high-risk drug?
Yes
who or what setting can amiodarone be initiated in?
This drug should only be intiated under specialist supervision, usually in a hospital setting
Does amiodarone have a short or long half life?
Amiodarone has a very long half life (several weeks) and only needs to be given ONCE daily.
What can high doses of amiodarone cause which requires it to be given in divided doses?
Can cause nausea unless divided
How long can it take for amiodarone to reach steady state?
It can take weeks or months to reach steady state, but IV amiodarone acts relatively rapidly
How can amiodarone affect the eyes?
Most patients will develop corneal microdeposits (which is reversible on withdrawal of amiodarone),,, these rarely interfere with vision but drivers may be dazzled by headlights at night.
- If vision is impaired or if optic neuritis or optic neuropathy occur, amiodarone must be stopped to prevent blindness and expert advice sought.
Why do people taking amiodarone need to protect them self from sunlight?
Amiodarone can cause phototoxicity (toxic response after exposure of the skin to light)
- Patients are advised to shield skin from light using wide-spectrum sunscreen
For patients taking amiodarone why does thyroid function need to be checked?
- Amiodarone contains iodine which can cause both hyper and hypothyroidism hence thyroid function should be monitored every 6 months.
What are the signs and symptoms associated with hypothyroidism associated with amiodarone use?
- Weight loss
- palpitations
- insomnia
How can amiodarone-induced hypothyroidism be treated?
Can be treated with replacement therapy without withdrawing amiodarone if it is essential; careful supervision is required
What skin colour discoloration can amiodarone cause?
Slight grey skin discolouration as a side effect –> this is common
Which other test is required before treatment with amiodarone?
- Liver function tests are required before treatment + then every 6 months
What would need to be done if hepatoxicity is suspected for patient taking amiodarone?
The drug should be stopped
For patients taking amiodarone, what signs should lead you to suspect pneumonitis?
if a new/progressive shortness of breath or cough develops.
What do neurological symptoms in patients taking amiodarone suggest?
suggests patient is experiencing peripheral neuropathy (nerve dysfunction)
Amiodarone increases which three drugs if they are taken with amiodarone?
Amiodarone increases plasma concentration of warfarin, digoxin and phenytoin
When amiodarone is taking with digoxin what is recommended about the digoxin dose?
- dose of digoxin needs to be halved
Which drugs if taken with amiodarone increases the risk of arrhythmias?
- Amitriptyline, lithium, quinines, erythromycin and haloperidol.
Can amiodarone be given in pregnancy and during breastfeeding?
No - possible risk of neonatal goitre; use only if no alternative
Avoid in breastfeeding as it is present in milk in significant amounts - theoretical risk of neonatal hypothyroidism from release of iodine
What does co-administration of amiodarone and simvastatin increase the risk of?
Myopathy
What is the mode of action of beta blockers?
- They reduce the cardiac output by blocking beta 1 receptors in the heart. They also act on beta 2 receptors in the liver, bronchi and pancreas
Can beta blockers be used in uncontrolled heart failure?
No it is contraindicated in uncontrolled heart failure
Which beta blockers are water soluble?
Use Acronym CANS
Celiprolol
Atenolol
Nadolol
Sotalol
They are water soluble and can’t cross the BBB, so they cause less sleep disturbances and less nightmares
Is it okay to stop beta-blockers abruptly?
No- advise patient to seek help from their GP
Why are beta blockers contraindicated in asthma?
due to their action on bronchi they can cause bronchospasm and should usually be avoided in patients with asthma.
Which beta blockers are cardio selective?
- Atenolol
- Bisoprolol
- Metoprolol
- Nebivolol
- Acebutolol
Why is there a risk of hypo/hyperglycaemia with betablockers in patients with or without diabetes?
- due to their action on the liver and pancreas they can affect carbohydrate metabolism causing either hyper or hypoglycaemia in patients with or without diabetes.
They can still be used in diabetes with caution - however they can MASK THE SYMPTOMS OF HYPOglycaemia
What are other uses of beta blockers?
- Angina (by reducing the work of the heart, and may prevent recurrence of MI
- They block sympathetic activity in HF
- Beta blockers can be used for anxiety (propranolol) and in the prophylaxis of migraine
Which two beta blockers can be used to reduce the mortality of heart failure?
- Bisoprolol
- Carvedilol
Can beta blockers be used to reduce blood pressure?
Yes through various ways (but not fully understood) mechanisms
Which drug is a cardaic glycoside?
Digoxin
What is digoxin-specific antibody fragments indicated for?
For the treatment of known or strongly suspected life-threatening digoxin toxicity associated
What is digoxin maintenance dose determined by?
Ventricular rate at rest
When using digoxin, heart rate should not be allowed to fall below what?
Should not usually be allowed to fall persistently below 60 beats per minute
Why is digoxin rarely used for rapid control of heart rate?
Even with intravenous administration, response may take many hours; persistence of tachycardia is therefore not an indication for exceeding the recommended dose.
The intramuscular route is not recommended.
In patients with heart failure who are in sinus rhythm, is a loading dose record?
no it is not required and a satisfactory plasma-digoxin concentration can be achieved over a period of about a week
Does digoxin have a short or long half life?
Has a long half-life and maintenance doses need to be given only once daily (although higher doses may be divided to avoid nausea)
What parameter is the most important determinant of digoxin dosage?
- Renal function
Is the plasma concentration alone of digoxin a reliable indicator of toxicity?
No, but the likelihood of toxicity increases progressively through the range 1.5 to 3 micrograms/litre for digoxin
Which electrolyte imbalance predisposes patient to digoxin toxicity?
Hypokalaemia - as potassium and digoxin compete for the same enzyme
less potassium means less competition for digoxin (which is a pro drug)
How is hypokalaemia in patients taking digoxin managed?
- by giving a potassium-sparing diuretic or if necessary potassium supplementation
If toxicity of digoxin is suspected, what should be done?
- Digoxin should be withdrawn
What is the drug action of digoxin?
Digoxin is a cardiac glycoside that increases the force of myocardial contraction and reduces conductivity within the atrioventricular (AV) node.
With which drugs if digoxin is taken then the dose of digoxin should be halved?
- Amiodarone
- Dronedarone
- Quinine
Which electrolyte imbalances including hypokalaemia increases risk of digoxin toxicity?
- Hypokalaemia
- Hypomagnesemia
- hypercalcaemia
If blood monitoring of digoxin levels is required when should this be taken?
Sample should be taken at least 6 hours after a dose
Which electrolyte imbalance does digoxin increase the risk of?
- increases the risk of hypokalaemia and ways to overcome this are to take potassium-sparing diuretics, potassium supplements or eating food with high potassium e.g. bananas
What are the signs and symptoms of digoxin toxicity?
- Nausea/ vomiting
- Blurred/yellow vision
- Weight loss
- anorexia
- Palpitations
- hallucinations
abdominal pain
What are people with digoxin toxicity (overdose) treated with?
Treated with a digoxin specific antibody fragment a.k.a. Digifab
Does digoxin liquid and tablets have the same bioavalibility?
No, thus the patient’s dose will change
What does tranexamic acid inhibit?
It inhibits fibrinolysis (impairs fibrin dissolution)
What can tranexamic acid be used to prevent?
to prevent bleeding ot to treat bleeding associated with excessive fibrinolysis (e.g. in surgery, dental extraction, obstetric disorders, and traumatic hyphaemia) and in the management of menorrhagia
Which other conditions or situations may tranexamic acid be also used for?
- hereditary angioedema
- Epistaxis
- Thrombolytic overdose
What is haemophilia?
It is a rare condition that affects the body’s ability to clot. It is usually inherited. Most people who have it are male.
What is desmopressin used for?
is used in the management of mild to moderate haemophilia and von Willebrand’s disease.
It is also used for fibrinolytic response testing.
Is the drug Etamsylate used for heavy menstrual bleeding?
No, it is less effective than other treatments.
Etamsylate reduces capillary bleeding in the presence of a normal number of platelets; however, it does not act by fibrin stabilisation, but probably by correcting abnormal adhesion.
What is the dose and regimen for tranexamic acid in menorrhagia treatment?
Adult - by mouth -
- 1g 3 times a day for up to 4 days, to be initiated when menstruation has started, maximum 4g per day
What is Von Willebrand (VWD)?
It is a blood disorder in which the blood does not clot properly. People with this disease have low levels of Von Willebrand factor, a protein that helps blood clot, or the protein doesn’t perform as well as it should.
What is the indication of fresh frozen plasma?
- Major bleeding in patients on warfarin following phytomenadione (if dried prothrombin complex is unavailable)
- Replacement of coagulation factors or other plasma proteins where their concentration or functional activity is critically reduced
Which drug can be used for blood clots causing blocked catheters and lines?
Epoprostenol (prostacyclin) - used for inhibition of platelet aggregation during renal dialysis when heparins are unsuitable or CI.
What is the drug action of epoprostenol?
Epoprostenol is a prostaglandin and a potent vasodilator.
It is also a powerful inhibitor of platelet aggregation.
What are the two types venous thromboembolism?
- Deep-vein Thrombosis (DVT)
- Pulmonary Embolism (PE)
What does a venous thromboembolism refer to?
A blood clot that forms in a vein which partially or completely obstructs blood flow
Within how many days hospital admission is referred to as having an hospital-acquired venous thromboembolism?
VTE that occurs within 90 days of hospital admission
What are the risk factors for VTE?
- surgery
- Trauma
- Significant immobility
- Malignancy
- obesity
- Acquired or inherited hypercoagulable states
- pregnancy and the postpartum period
- hormonal therapy (Combined hormonal contraception or hormone replacement therapy)
Out of the two, which is the most common type of VTE?
DVT is the most common form of VTE.
What are the common sites in which a DVT usually occurs?
Usually occurs in the deep veins of the legs or pelvis but may affect other sites such as the upper limbs, and the intracranial and splanchnic veins.
What are the symptoms of DVT?
- Unilateral localised pain
- Swelling
- tenderness
- skin changes
- and/or vein distension
How does a pulmonary embolism (PE) usually occur?
- most commonly occurs when a thrombus, usually from a DVT, travels in the blood (embolus) and obstructs blood flow to the lungs causing respiratory dysfunction.
What are the symptoms of pulmonary embolism?
- Chest pain
- Shortness of breath
- and/ or haemoptysis
What is haemoptysis?
Haemoptysis is the coughing up of blood
For venous thromboembolism, what must all patients undergo?
A risk assessment to identify their risk of venous thromboembolism (VTE) and bleeding
What are the two methods of thromboprophylaxis?
- mechanical
- pharmacological
What are the options of mechanical thromboprophylaxis?
- anti-embolism stockings that provide graduated compression and produce a calf pressure of 14-15mmHg
- intermittent pneumatic compression
How long should anti-embolism be worn for?
- They should be worn day and night until the patient is sufficiently mobile
Which patients should anti-embolism stockings not be offered to?
- patients admitted with acute stroke or those with conditions such as peripheral arterial disease
- peripheral neuropathy
- severe leg oedema
- local conditions (e.g. gangrene, dermatitis)
For thromboprophylaxis how soon should pharmacological prophylaxis start if this option is chosen?
- Should start as soon as possible or within 14 hours of admission
Can certain patients with bleeding risk be given pharmacological thromboprophylaxis?
Patients with risk factors for bleeding (e.g. acute stroke, thrombocytopenia, acquired or untreated inherited bleeding disorders) should only receive pharmacological prophylaxis when their risk of VTE outweighs their risk of bleeding.
Should patients receiving anticoagulant treatment who are at high risk of VTE be considered for prophylaxis of VTE?
These patients should be considered for prophylaxis if their anticoagulant treatment is interrupted, for example during the peri-operative period
To reduce the risk of VTE in surgical patients which form of anaesthesia should be used?
Regional anaesthesia should be used if possible over general anaesthesia
What is the difference between regional and general anaesthesia?
In general anesthesia, you are unconscious and have no awareness or other sensations. In regional anesthesia, your anesthesiologist makes an injection near a cluster of nerves to numb the area of your body that requires surgery.
In surgical patients how long should mechanical prophylaxis continue?
Until the patient is sufficiently mobile or discharged from hospital (or for 30 days in spinal injury, elective spinal surgery or cranial surgery).
In terms of pharmacological prophylaxis for surgery patients, what types of surgeries are low molecular weight heparin considered?
- general and orthopaedic surgery
What is orthopaedics?
Orthopedic surgery or orthopedics, is the branch of surgery concerned with conditions involving the musculoskeletal system. Orthopedic surgeons use both surgical and nonsurgical means to treat musculoskeletal trauma, spine diseases, sports injuries, degenerative diseases, infections, tumors, and congenital disorders
In which surgery patients is Heparin (unfractionated) preferred in for thromboprophylaxis?
- In patients with renal impairment
Which surgery patients is fondaparinux an option for thromboprophylaxis?
or patients undergoing abdominal, bariatric, thoracic or cardiac surgery, or for patients with lower limb immobilisation or fragility fractures of the pelvis, hip or proximal femur.
How long should pharmacological thromboprophylaxis continue in general surgery?
- should usually continue for at least 7 days post-surgery or until sufficient mobility has been re-established.
In cancer surgery or abdominal surgery - how long should pharmacological thromboembolism continue?
- extended to 28 days after major cancer surgery in the abdomen
- and to 30 days in spinal surgery
What thromboprophylaxis is recommended for patients undergoing an elective hip replacement?
should be given thromboprophylaxis with either a low molecular weight heparin administered for 10 days followed by low-dose aspirin for a further 28 days, or a low molecular weight heparin administered for 28 days in combination with anti-embolism stockings until discharge, or rivaroxaban. If these options are unsuitable, apixaban or dabigatran etexilate can be considered as alternatives. If pharmacological prophylaxis is contra-indicated, anti-embolism stockings can be used until discharge.
