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35 Cards in this Set
- Front
- Back
- 3rd side (hint)
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When do the complications of cardiopulmonary bypass become evident?
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Usually after 2 hours- time related
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What is used to help protect organs against hypotension in cardiothoracic surgery?
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hypothermia- 30-34 degrees
For complex aortic arch aneurism surgery- 18 degrees Rewarming over 30-40 minutes Haemodilution (haematoctir 25-30%- to reduce red cell loss, blood product use and to improve small vessel blood flow in hypothermic conditions |
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How is the heart stopped and re-started for cardiac surgery
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clamp distal ascending thoracic aorta
infuse "cardioplegia solution"- oxygenated blood with added potassium: arrests heart and reduces metabolic requirements Arrest time 30-90 min usual but 180 min possible Sinus rhythm usually restored within 1-2 min of re-establishing coronary blood flow |
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What cardiac surgeries are performed without cardiopulmonary bypass
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PDA closure
coarctation of aorta repair mitral valvotomy pericardiectomy Selected coronary artery bypass |
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Re-stenosis rates for coronary stenting?
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5-10%
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Normal CABG procedure?
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sternotomy performed
LITA (LIMA) anastomosed to LAD If < 60 RIMA anastomosed to 2nd most important affected vessel Proximal inflow either from ascending aorta, subclavian artery or pedicle graft off internal thoracic artery |
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Timing of CABG?
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Usually takes 3-4 hours including cardiac arrest 30-60 min
bypass 60-90 |
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Where are drains placed after CABG?
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Behind sternum and into pleural cavity if breached
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Recovery post CABG?
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24-48 hrs ICU
Mobilised day 1-2 (aspirin re-started) Rapid recovery: return to work 4 weeks and full activity 3m |
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Operative morbidity and mortality in CABG?
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1% mortality
1% stroke, 2% MI, 1% infections 2% haemorrhage |
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In what groups does CABG provide a survival advantage?
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Left main stenosis, high grade proximal LAD, triple vessel, LV dysfunction
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What are the two most common valve pathologies in western countries?
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calcific aortic stenosis and degenerative myxomatous mitral regurgitation (collagen and elastin abnormalities and increased mucopolysaccharide production)
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1st symptom in valve pathology
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Dyspnoea- indicates exhaustion of the cardiac compensatory mechanism and poor prognosis if patient is left untreated
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Which patients with valcular disease need coronary angiography?
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Performed in patients >40 to screen for coexistant coronary artery disease/>35+ coronary risk factors/chest pain/signs of ischemua
30% of patients undergoing cardiac valve surgery require concommittant CABG |
Indications for CABG include: >70% stenosis of coronary arteries
reasonable for 50-70% stenosis |
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What are indications for surgery on an aortic valve?
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Mean gradient of more than 40mmHg (AS) or left ventricular end diastolic diameter > 60 (AR)
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What is involved in aortic valve surgery?
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making a transverse cut 2-3cm from aortic valve
remove valve and calcification reolace with prosthesis |
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Management of rheumatic mitral valve stenosis?
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percutaneous balloon valvuloplasty
(femoral vein catheterisation, catheter then goes across the intra-atrial septum)- alternative is closed mitral valvotomy via left thoracotomy under TOE guidance |
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What are the indications for open mitral valve replacement (for rheumatic disease)
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valve leaflet thickening, calcification, fused chordae and LA thrombus
May need replacement if severely distorted |
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Management of myxomatous degenerative MR
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localised: repair
widespread: replacement: <70 get a mechanical valve |
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INR for mechanical valve?
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2.5-3.5
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Prophylaxis against thromboembolism in a patient with a xenograft?
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low dose aspirin if the patient is in sinus rhythm
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Valve replacement options in younger patients?
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mostly <70 get mechanical valve
human cadaver allograft: remore area, contact sports, endocarditis affecting the aortic valve annulus 15-50: pulmonary autograft (ross) |
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When are antibiotics given after valcular surgery?
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up to 48 hours post-op
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When is warfarin commenced after valve replacement?
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24 hours post-op
aim for therapeutic INR by day 7 Usually also kept on diuretics and ACEI for 3 months |
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Is the operative mortality higher for aortic or mitral valve replacement surgery?
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mitral (3% mortality) vs aortic (1%)
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Pathophysiology of thoracic aortic aneurosm
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Myxomatous degeneration of the aortic wall media
Dilatation of the thoracic aorta of >5cm is associated with a marked increase in the possibility of rupture/dissection so elective repair is advised |
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ECG and symptoms of thoracic aortic aneurism?
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usually asymptomatic until rupture or dissect
ECG is usually normal |
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Diagnosis of thoracic aortic aneurism
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TEE
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Follow-up after repair of thoracic aortic aneurism
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serial CT/echo because other parts of the aorta (descending, thoracic or abdominal) may dilate over time
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When does an intra-aortic baloon pump inflate and deflate?
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Inflates during diastoly- increases coronary and systemic perfusion and diastolic blood pressure
Deflates during systole- reducing LV afterload Usual duration of use 1-5d |
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Potential problems with use of intra-aortic baloon pump?q
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leg ischemia
systemic infection haemolysis/thrombocytopenia |
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Where are lung carcinoids usually found?
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80-90% in big bronchi
10% of all carcinoids no association with external environmental toxin |
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Management of lung carcinoids
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All should be resected unless metastatic/ c/i to surgery- most common is anatomic lobectomy
bronchoscopic/ laser wont get whole tumour but can be used to pallate |
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Management of metastatic lung carcinoids?
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resect distant mets in some
chemoradio- not much sucess carcinoid synrome: octreotide |
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Max storag time for donated kindeys
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30-36 hours
12-20 hrs for liver |
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