Revision - Anaesthetics & Cardiology Flashcards
IV vs IM naloxone in opioid overdose?
IV > IM if the patient has IV access
If no IV access then IM naloxone
How long prior to surgery should diclofenac be stopped?
48h before
How long prior to major surgery should aspirin be stopped?
7 days
How long prior to elective surgery with spinal anaesthesia should aspirin be stopped?
Can continue aspirin throughout the perioperative period as it does not pose a significant risk for spinal or epidural haematoma.
When patients are positioned prone for lumbar decompression surgery, what is the most appropriate anaesthesia technique?
GA with ETT intubation
What type of anaesthesia is often preferred in patients with severe COPD?
Regional anaesthesia e.g. spinal or epidural (where possible e.g. elective knee surgery)
Is there a higher risk of bleeding with COX-1 or COX-2 inhibitors?
COX-2 inhibitors
Mx of diabetics patients prior to elective surgery with poorly controlled blood glucose levels?
Delay surgery until satisfactory glycemic management is achieved.
Role of pre-oxygenation?
Preoxygenation replaces nitrogen in the functional residual capacity of the lungs with oxygen, extending the time before arterial oxygen desaturation occurs during periods of apnea, such as during intubation.
In patients with a recent MI, what investigation is advisable prior to surgery?
A preoperative coronary angiography.
To assess the state of coronary arteries and guide further management, including the possibility of revascularisation, which might reduce the risk of perioperative cardiac events.
Post-op complications can be classified by time.
What defines a:
a) immediate
b) early
c) late/long-term complications?
a) <24h
b) <30 days
b) >30 days (or after discharge)
What is atelectasis?
A common post-op complication in which basal alveolar collapse can lead to respiratory difficulty.
Cause of post-op atelectasis?
It is caused when airways become obstructed by bronchial secretions.
When should atelectasis be suspected?
In the presentation of dyspnoea and hypoxaemia around 72 hours postoperatively.
Mx of post-op atelectasis?
1) positioning the patient upright
2) chest physio & breathing exercises
What should the skin be prepared with to reduce the risk of surgical site infections?
alcoholic chlorhexidine
What complication are patients post pneumonectomy at risk of?
Pulmonary oedema: loss of lung volume makes these patients very sensitive to fluid overload.
How can a post-op anastamotic leak present?
Generalised sepsis causing mediastinitis or peritonitis depending on site of leak.
What surgery is the long thoracic at risk of being damaged in?
Axillary node clearance
In post-op ileus, does hypovolaemia and electrolyte disturbances occur before or after N&V?
Before
What is a potential, and serious, cause of new onset AF following gastrointestinal surgery?
Anastomotic leak
How soon post-op does an anastomotic leak usually present?
5-7 days post-op
How can an anastomotic leak be diagnosed?
Abdo CT
What is Charcot joint?
AKA neuropathic joint.
It describes a joint which has become badly disrupted and damaged secondary to a loss of sensation.
Commonly seen in diabetics.
What are the risk factors for pseudogout?
1) Increasing age (main risk factor)
2) Haemochromatosis
3) Hyperparathyroidism
4) Wilson’s disease
5) Acromegaly
6) Low Mg, low phosphate
Xray features in pseudogout?
Chondrocalcinosis –> can be seen as linear calcifications of the articular cartilage
Mx of VT?
300mg amiodarone (loading dose)
Followed by 24h infusion
If patient with broad complex regular tachycardia has previously confirmed SVT with bundle branch block, what is management?
Treat as for regular narrow complex tachycardia (i.e. vagal maouevres –> adenosine –> verapamil or beta blockers –> synchronised DC shocks).
If tachycardia is broad complex with IRREGULAR rhythm, what are the possibilities of causes?
1) AF with BBB (most likely in stable patient)
2) Torsades de pointes
3) AF with ventricular pre-excitation
If tachycardia is broad complex with IRREGULAR rhythm, what is the management?
Seek expert help!
If AF with BBB –> treat as for irregular narow complex (beta blocker & anticoagulate if duration >48h)
Polymorphic VT (e.g. tosades de pointes) –> IV magnesium sulphate
What is 3rd line mx of SVT if 18mg of adenosine has not been effective?
Verapamil or beta blocker
Contraindications of adenosine?
1) asthma
2) COPD
3) long QT
4) decompensated HF
5) 2nd or 3rd degree AV block
What is alternative to IV adenosine in asthmatics?
IV verapamil
Why are ACEi contraindicated in HOCM?
ACEi reduce afterload which may worsen the LVOT gradient.
What murmur is heard in pulmonary stenosis?
Ejection systolic that is louder on inspiration
Is an ejection systolic murmur characteristic of aortic stenosis louder on inspiration or expiration?
Expiration
Think RILE
Why is moderate to severe aortic stenosis a contraindication to ACEi?
As the vasodilator effect of ACEi might lead to a reduction in coronary perfusion pressure, leading to cardiac ischaemia.
What is the site of action of furosemide?
Ascending loop of Henle –> inhibits the K-Cl co-transporter
Management of infective endocarditis causing HF?
Indication for emergency valve replacement
What is the 2nd line drug treatment for angina pectoris if 1st line drugs (beta blockers or CCBs) are contraindicated or not tolerated?
Nicorandil
Contraindication of nicorandil?
LV failure
What is the JVP increasing with inspiration known as?
Kussmaul’s sign
Seen in constrictive pericarditis
What cardiac defect are alcoholics at risk of?
Dilated cardiomyopathy
This would cause a reduction in LV EF, with a dilated LV.
What are J waves?
A small hump at the end of the QRS complex (seen in hypothermia)
What should patients on warfarin undergoing emergency surgery receive?
PCC
How can ACEi affect BNP levels?
Can give falsely low BNP levels
What class of drug is digoxin?
Cardiac glycoside
Mechanism of digoxin?
1) Decreases conduction through the AV node which slows the ventricular rate in atrial fibrillation and flutter.
2) Increases the force of cardiac muscle contraction due to inhibition of the Na+/K+ ATPase pump. Also stimulates vagus nerve
What is the classic precipitating factor for digoxin toxicity?
Hypokalaemia
What investigation should all patients with suspected acute pericarditis have?
Echo
