Mod 7b: CVS disease and anaesthesia Flashcards
True or false:
Anaesthesia may aggravate/precipitate hypertensive complications?
True
What is the effect of anaesthesia on hpt
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
How do diuretics aggravate anaesthetic agents?
cause volume depletion and electrolyte disturbances
How do b-blockers aggrevate anaesthetic agents
causes bradycardia and is negatively inotropic
how do Ca channel blockers aggrevate anaesthetic agents
hypotension
How do ACE-inhibitors aggravate anaesthetic agents
exaggerated hypotension
What forms part of the hpt risk evaluation?
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
How do you assess the hypertensive patient
BP chart + regular BP check
Effort tolerance
End organ function
ECG + CXR
What are the principles of management in HPT?
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
What is the major cause of peri-operative deaths?
IHD- perioperative MI has plus minus 50% mortality rate
What is included in IHD risk evaluation?
ACS = extremely high risk
Stable angina + poor effort tolerance= elevated risk
Good effort tolerance(>2 flights of stairs)= normal risk
Recent MI is less than how many months is a high risk for re-infarction
< 6mnths
What must be done in patient assessment with IHD?
ECG: resting + stress
Effort tolerance
Beware the diabetic
What is the peri-operative management of IHD?
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
What post operative monitoring is needed in IHD and why?
Good monitoring and analgesia + supplemental O2 is needed
Why? most peri-operative MI is in first 48-72 hrs after surgery
What must be decided when a patient has a mixed valvular disease?
Decide on the dominant lesion
Name 5 things that complicate VHD?
*Atrial fibrillation
*Pulmonary hypertension
*Cardiac failure
*Bacterial endocarditis
*Myocardial ischaemia
Why is CO limited in stenotic lesions to the degree of stenosis
Atrium/ventricle hypertrophies, needs long time to expel blood through stenotic valve
What should you try and achieve under anaesthesia in stenotic valvle lesions
Slow HR
Sinus rhythm
Good pre-load
Good inotropy
Maintain afterload
What cant stenotic valve patients tolerate
sudden drops in BP
Sudden changes in blood volume
What are the characteristics of regurgitant valve lesions
CO is limited by degree of regurgitation
Ventricle is volume loaded + dilates
How do you optimise a regurgitant lesion when giving anaesthesia
faster rate
Sinus rhythm
good preload
afterload reduction
What are the main 6 aetiologies of CCF?
*Hypertension
*Ischaemic heart disease
*Valvular heart disease
*Endocrine disease (thyroid, phaeo)
*Nutritional
*Cardiomyopathies
How do you manage CCF intraoperatively?
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
What is important to do in dysrythmias
assess the effect on haemodynamics
Name 3 things anaesthesia can do to dysrythmia
aggravate, precipitate, cure
How do you manage a dysrythmia
Exlude HYPOXIA, hypercarbia and acidosis
If haemodynamically significant: fluid and vasopressor support, look for cause and treat
If haemodynamically insignificant: leave and treat cause
