Mod 7b: CVS disease and anaesthesia

Question 1

True or false:
Anaesthesia may aggravate/precipitate hypertensive complications?

Answer 1

True

Question 2

What is the effect of anaesthesia on hpt

Answer 2

hypertensive crisis with potent stimuli: laryngoscopy+ intubation/surgical stimulation

Increased sensitivity to vasodilatation of anaesthetic agents-> HYPOTENSION

Often volume depleted->tolerate fluid/blood loss poorly

Low CO-> compromise organ perfusion

Anti-hpt drugs affects anaesthesia

Question 3

How do diuretics aggravate anaesthetic agents?

Answer 3

cause volume depletion and electrolyte disturbances

Question 4

How do b-blockers aggrevate anaesthetic agents

Answer 4

causes bradycardia and is negatively inotropic

Question 5

how do Ca channel blockers aggrevate anaesthetic agents

Answer 5

hypotension

Question 6

How do ACE-inhibitors aggravate anaesthetic agents

Answer 6

exaggerated hypotension

Question 7

What forms part of the hpt risk evaluation?

Answer 7

HPT treated+ well controlled- normal risk

Treated, uncontrolled- higher risk

untreated, uncontrolled- highest risk

Diastolic BP>120 for elective surgery- BP control, postpone for 2-6wks

Question 8

How do you assess the hypertensive patient

Answer 8

BP chart + regular BP check
Effort tolerance
End organ function
ECG + CXR

Question 9

What are the principles of management in HPT?

Answer 9

Optimise BP control
Continue anti-hpt therapy
premed to minimise anxiety
BLUNT INTUBATION RESPONE
Avoid >25% drop in systolic/Mean BP
Adequate post-op analgesia

Question 10

What is the major cause of peri-operative deaths?

Answer 10

IHD- perioperative MI has plus minus 50% mortality rate

Question 11

What is included in IHD risk evaluation?

Answer 11

ACS = extremely high risk

Stable angina + poor effort tolerance= elevated risk

Good effort tolerance(>2 flights of stairs)= normal risk

Question 12

Recent MI is less than how many months is a high risk for re-infarction

Answer 12

< 6mnths

Question 13

What must be done in patient assessment with IHD?

Answer 13

ECG: resting + stress
Effort tolerance
Beware the diabetic

Question 14

What is the peri-operative management of IHD?

Answer 14

Good premed

Maintain CVS stability(slow rate, good diastolic BP)-> 5 lead ecg, invasive arterial line

Appropriate agent selection:
- Induction: etomidate/propofol(very slowly+ cautiously)
- Volatiles: isoflurane/sevoflurane
- All muscle relaxants are safe

Good analgesia:
- Fentanyl->gold standard, morphine acceptable
- LA/REGIONAL considered

Question 15

What post operative monitoring is needed in IHD and why?

Answer 15

Good monitoring and analgesia + supplemental O2 is needed

Why? most peri-operative MI is in first 48-72 hrs after surgery

Question 16

What must be decided when a patient has a mixed valvular disease?

Answer 16

Decide on the dominant lesion

Question 17

Name 5 things that complicate VHD?

Answer 17

*Atrial fibrillation
*Pulmonary hypertension
*Cardiac failure
*Bacterial endocarditis
*Myocardial ischaemia

Question 18

Why is CO limited in stenotic lesions to the degree of stenosis

Answer 18

Atrium/ventricle hypertrophies, needs long time to expel blood through stenotic valve

Question 19

What should you try and achieve under anaesthesia in stenotic valvle lesions

Answer 19

Slow HR
Sinus rhythm
Good pre-load
Good inotropy
Maintain afterload

Question 20

What cant stenotic valve patients tolerate

Answer 20

sudden drops in BP
Sudden changes in blood volume

Question 21

What are the characteristics of regurgitant valve lesions

Answer 21

CO is limited by degree of regurgitation
Ventricle is volume loaded + dilates

Question 22

How do you optimise a regurgitant lesion when giving anaesthesia

Answer 22

faster rate
Sinus rhythm
good preload
afterload reduction

Question 23

What are the main 6 aetiologies of CCF?

Answer 23

*Hypertension
*Ischaemic heart disease
*Valvular heart disease
*Endocrine disease (thyroid, phaeo)
*Nutritional
*Cardiomyopathies

Question 24

How do you manage CCF intraoperatively?

Answer 24

Optimise medical therapy

Invasive monitoring indicated for surgery: arterial line/central line if inotropic support needed

Maintain optimal preload and inotropy, afterload reduction

Regional anaesthesia=beneficial, NOT if patient is in uncontrolled failure

Question 25

What is important to do in dysrythmias

Answer 25

assess the effect on haemodynamics

Question 26

Name 3 things anaesthesia can do to dysrythmia

Answer 26

aggravate, precipitate, cure

Question 27

How do you manage a dysrythmia

Answer 27

Exlude HYPOXIA, hypercarbia and acidosis

If haemodynamically significant: fluid and vasopressor support, look for cause and treat

If haemodynamically insignificant: leave and treat cause