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?