cardiac for the final frca written exam
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Cardiac for the Final FRCA written exam
D R K I M C A I N E S
S T 6 A N A E S T H E T I C S ( A D V A N C E D
C A R D I O T H O R A C I C S )
Overview
• "Normal" cardiac surgery patient pathway (5 mins)
• Cardiopulmonary bypass (5 mins)
• Common FRCA question topics (45 mins)
"Normal" patient pathway
Operations
• Revascularisation for IHD
• Valve replacements/ repair
• Aortc surgery
Preassessment
• History
• Examination
• ECG
• Angio
• Echo
• CXR
• Carotid dopplers
• Lung function studies
Risk assessment
++++
• Post infarct rupture
+++
• Previous cardiac surgery
• Active endocarditis
• Critical preop state
• Poor LVEF <30%
• Thoracic aorta surgery
++
• Extracardiac arteriopathy
• Neurologic dysfunction
• Serum creatinine >200micromol/l
• Rest angina
• Recent MI (<90 days)
• Recent PAP >60mmHg
• Emergency
• Major Cardiac procedure
On the day
• Anaesthetic assessment (night before)
• Premedication (analgesia/benzo/PPI)
• AAGBI monitoring + arterial line + central line +/- PA catheter +/- TOE +/- CNS monitoring
• Cardiac induction
• TXA
• Heparinisation/ coagulation monitoring
• Antibiotic prophylaxis
Medications
Beta Blockers Give
ACE Is/ ARBs Omit
Statin Give
Aspirin Usually Give
PPI Give
Nitrates Give
CCBs Give
Drawing up...• Induction agent
• Paralysis agent
• Opiate
• Emergency drugs
• Antibiotics
• TXA
• Heparin
• Protamine**
CPB
• Protect the heart
• Protect the body
This Photo by Unknown author is licensed under CC BY-SA.
CPB
• Oxygenation
• Elimination of carbon dioxide
• Blood circulation
• Cooling & rewarming
• Provide a bloodless field by diversion
• Reduced myocardial oxygen demand
Diastolic arrest
Prevent stretch
Temperature control
Cardioplegia
Anticoagulation
Arterial cannulation
Venous cannulation
CPB
"Full flow..Lungs off"
Post Op
• CICU
• "Warm, wake, wean"
Temp>36
Normal acid base
Adequete haemostasis
Stable rhythm
Good urine output
Common Themes
Year March Sept
2021 Cardiac disease in pregnancy -
2020 Anticoagulation and CPB Balloon pump
2019 Dilated cardiomyopathy Cardioplegia
2018 CIEDs Lung resection / OLV
2017 OPCAB Balloon pump
2016 Aortic stenosis Cardiac tamponade
2015 Anticoagulation for CPB Neuro complications
2014 Rigid Bronchoscopy Cardioplegia
2013 DLT/lung resection/OLV Cardiac tamponade
2012 Cardiac US? OPCAB
2011 Neuro complications Cardiac US
2010 Balloon pump no cardiac question
Year March Sept
2021 Cardiac disease in pregnancy -
2020 Anticoagulation and CPB Balloon pump
2019 Dilated cardiomyopathy Cardioplegia
2018 CIEDs Lung resection / OLV
2017 OPCAB Balloon pump
2016 Aortic stenosis Cardiac tamponade
2015 Anticoagulation for CPB Neuro complications
2014 Rigid Bronchoscopy Cardioplegia
2013 DLT/lung resection/OLV Cardiac tamponade
2012 Cardiac US? OPCAB
2011 Neuro complications Cardiac US
2010 Balloon pump no cardiac question
Question One
a)What are the central and peripheral neurological complications of coronary artery bypass surgery? (7 marks)
b)What are the risk factors for central neurological complications? (6 marks)
c)How can the incidence of central neurological complications be reduced? (7 marks)
5 minutes...
Question One
a)What are the central and peripheral neurological complications of coronary artery bypass surgery? (7 marks)
b)What are the risk factors for central neurological complications? (6 marks)
c)How can the incidence of central neurological complications be reduced? (7 marks)
Neurocomplications
• 2011 & 2015
• Spectrum – neurocognitive dysfunction
(25-80%) to CVA (1- 5%)
• Increases mortality, LOS, reduced
independence
FRCA college pink book question
Neuro complicatons
C E N T R A L
• Stroke (hypoperfusion and/ or embolism and/ or haemorrhage)
• Delerium/ Post operative cognitive dysfunction
• Seizures
• Ischaemic optic neuropaty
• Visual field defects
• Emergence of primitive reflexes
P E R I P H E R A L
• Brachial plexus injury – traction
• Peripheral nerve palsy
• Phrenic nerve palsy
• Anterior intercostal nerve injury
Neuro complications
P A T I E N T F A C T O R S
• Advanced age
• Atheroma of the proximal aorta
• Previous stroke/ neuro disease
• Female gender
• Diabetes/ ETOH XS
• AF/ Dysrhythmmias/ Unstable angina
• Renal failure
• Resp disease
• Hypertension > 180 mmHg
P R O C E D U R A L F A C T O R S
• Long CPB time
• Use of IABP
• CPB
• Tranexamic acid**
• Macro/ micro emboli
• Combined surgery surgery
• Previous CABG surgery
Risk reduction
• Anticoagulation aiming for ACT > 400
• Modify technique -avoid multiple aortic cross- clamping
• Image proximal aorta - epi-aortic ultrasound if atheroma noted on TOE
• Optimise conditions during CPB
✓ Maintain adequate pressure and flow
✓ Avoid air entrainment
✓ Use membrane oxygenator/arterial line filter/?centrifugal pump
✓ Avoid too rapid rewarming or overshoot hyperthermia
• Minimal CPB time
• Off pump techniques
• Optimisation of comorbidities including blood sugar and BP
• Use neurological monitoring -TCD, NIRS, EEG
• Pharmacological neuroprotection - profolol, steroids, NMDA antags, lidocaine, magnesium, barbiturates (no evidence for any of this really!)
Question Two
a)What are the purposes (3marks) typical composition (4 marks) and physiological actions of cardioplegia solutions (5 marks)?
b)By which routes can solutions of cardioplegia be administered? (2 marks)
c)What are the possible complications of cardiolpegia soluition administration? (6 marks)
5 minutes...
Question Two
a)What are the purposes (3marks) typical composition (4 marks) and physiological actions of cardioplegia solutions (5 marks)?
b)By which routes can solutions of cardioplegia be administered? (2 marks)
c)What are the possible complications of cardiolpegia soluition administration? (6 marks)
Cardioplegia
• 2014 & 2019
• Myocardial protection during cardiac surgery
• Reduced myocardial oxygen consumption
Emptying
Arrest
Hypothermia
• Minimising reperfusion injury
• Delivers metabolic substrates
Cardioplegia composition
• Blood (4:1) vs crystalloid
• Warm vs cold
Asystolic arrest PotassiumMagnesium (antagonises Ca)
Substrate GlucoseGlutamateAspartate
Osmotic agents GlucoseMannitolPotassium
Buffers BicarbonateTromethamineBlood
Oxygen Blood
Cardioplegia delivery
• Retrograde – coronary sinus
• AR
• Aortic surgery
• With Antegrade
• Severely diseased coronaries
• Antegrade – coronary arteries
Complications
• Trauma
• Air bubbles
• Myocardial oedema
• Bleeding (high perfusion pressures)
• Difficulty restarting heart due to residual effects
• Systemic electrolyte disturbances
• Inadequete myocardial protective effects
Question Three a) Describe the principles of using an intra aortic balloon pump (IABP). (6 marks)
b) What are the indications to use of IABP? (4 mark)
c) What are the contraindications to use of IABP? (4 marks)
d) List the main complications of using this device. (6 marks)
5 minutes...
Question Three a) Describe the principles of using an intra aortic balloon pump (IABP). (6 marks)
b) What are the indications to use of IABP? (4 mark)
c) What are the contraindications to use of IABP? (4 marks)
d) List the main complications of using this device. (6 marks)
Intra-aortic Balloon Pumps
Intra–Aortic Balloon Pumps (IABPs)
• 2010, 2017 & 2020
• Positioned distal to the left subclavian artery
• Triggered by ECG or arterial pressure wave
• Helium (30 –40 ml)
• Heparinisation (APTT ratio 1.5 -2.0)
Intra–Aortic Balloon Pumps (IABPs)
• Inflation with dichrotic notch (1)
• Rapid inflation increases aortic pressure (2)
• Diastolic peak pressure ensures coronary perfusion (3)
• Defalation at end diastole (4) results in rapid pressure fall resulting in reduced impedence to AV opening
• The IABP results in less myocardial work for the next systolic ejection (5)
Intra–Aortic Balloon Pumps (IABPs)
• Counter pulsation
• Diastolic inflation – increases coronary perfusion & myocardial oxygen supply
• Systolic deflation – facilitates forward ejection & reduces myocardial oxygen demand
Indications
• Cardiogenic shock
• Unstable angina despite maximal pharmacological therapy
• Failure to wean from CPB
• Bridge to transplant
• High risk cardiac procedure
Contraindications
• Aortic regurgitation
• Aortic aneurysms
• Significant friable atherosclerotic plaques in the aorta
• Aortic disseaction (ascending > descending)
• Severe failure or no recovery forseeable
• Uncontrolled sepsis
• Aortic or femoral grafts
• PVD
• HOCM
Complications
• Vascular injury (perforation, dissection, AV fistula)
• Haemorrhage-retroperitoneal haematoma
• Haemolysis/HIT
• Thromboembolism
• Infection
• Tissue ischaemia (gut, left arm, spinal cord>paraplegia, leg>compartment syndrome, renal)
• Balloon rupture> gas embolism
• Haemodynamic problems associated with inflation / deflation timing errors
• Cardiac decompensation on removal
Question Four
• Credit: Paddy Knowles,
Consultant Anaesthetist,
Sheffield
You are asked to review a 65-year-old man on the Cardiac Intensive Care Unit who underwent coronary artery bypass surgery earlier in the day.
A. List 6 clinical features which would suggest that this patient is developing acute cardiac tamponade? (6 marks)
B. How would you confirm the diagnosis (1 mark)
C. Suggest two other investigations that might prove helpful in the acute management of this patient. (2 marks)
D. The cardiology registrar offers to drain the pericardial collection by pericardiocentesis -why is this offer politely declined? (2 mark)
E. Outline the key steps in managing this patient (8 marks)
F. What is the most likely cause of iatrogenic cardiac tamponade in a General ITU setting? (1 mark)
5 minutes...
Question Four
• Credit: Paddy Knowles,
Consultant Anaesthetist,
Sheffield
You are asked to review a 65-year-old man on the Cardiac Intensive Care Unit who underwent coronary artery bypass surgery earlier in the day.
A. List 6 clinical features which would suggest that this patient is developing acute cardiac tamponade? (6 marks)
B. How would you confirm the diagnosis (1 mark)
C. Suggest two other investigations that might prove helpful in the acute management of this patient. (2 marks)
D. The cardiology registrar offers to drain the pericardial collection by pericardiocentesis -why is this offer politely declined? (2 mark)
E. Outline the key steps in managing this patient (8 marks)
F. What is the most likely cause of iatrogenic cardiac tamponade in a General ITU setting? (1 mark)
Cardiac Tamponade
2013 & 2016
Cardiac Tamponade
• “Cardiac tamponade is the compression of
the heart chambers caused by
accumulation of fluid in the pericardial
space.”
• Common causes include…
• Pericarditis
• TB
• Trauma
• Malignancy
• Iatrogenic – Central line/ PA catheter
• Cardiac surgery
• Procedures
Cardiac Tamponade
Symptoms
• Chest pain
• Dyspneoa
• Orthopnoea
Others
• •Abrupt cessation of bleeding from drains
• •Agitation/ anxiety
• •Cardiac arrest
• •Signs “obstructive shock”
• Low MAP
• Cool peripheries
• Poor end organ perfusion – low UO
• Pulse volume variation
• CVP increased
• Distended neck veins
• Tachycardia
• Sweating
Full, Fast & Tight
•Increase preload •Aim for sinus rhythm and avoid bradycardia
•Maintain SVR (maintain compensatory
sympathetic tone – HR and SVR)
•Maintain contractility •Inotropes, vasopressors, avoid high
PEEP and high TV
Management
• ABC...
• Alert surgeons and theatre team
• Bloods and correct any coagulopathy (ABG and POC coagulation testing)
• Echo can be used to confirm diagnosis
• Re-open on CICU if in extremis
• Maintain sympathetic drive with vasopressors
• Cautious induction with surgeons scrubbed and patient draped
Management
• NO place for pericardiocentesis
Wouldn’t drain clot
Liable to damage grafts from earlier surgery
Relative contraindication if anticoagulated
TIPS
• Exam templates
• College questions
• Timing
• Taster days
• Resources...
O T H E R Q U E S T I O N S
Anticoagulation
Aortic Stenosis
OPCAP
Cardiomyopathy
CIEDs
Resources
• RCOA pink book
• Past paper templates
• PASTEST Books
• NI school of anaesthesia website
• Don’t forget the SBA/MCQ - practice practice practice
We've covered...
• Cardiac patient pathway
• A few common question topics
• Neurocomplications
• Cardioplegia
• IABP
• Tamponade
Questions?
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