aprotinin

A January 26, 2006, article published in the New England Journal of Medicine (NEJM) described the findings from an observational study of 4,374 patients (1,295 treated with Trasylol) scheduled for CABG surgery at multiple centers in multiple countries. 

Compared to those receiving no preventive drug therapy and after propensity adjustment, primary patientsreceiving Trasylol had a higher risk for dialysis or creatinine increase; myocardial infarction or heart failure; or stroke, encephalopathy or coma.  Compared to those receiving no preventive drug therapy and after propensity adjustment, complex patients receiving Trasylol had a higher risk for dialysis or creatinine increase, but not for heart complications, stroke, encephalopathy or coma.  Risks for adverse renal events increased with the administered Trasylol dose.  All three drug therapies (Trasylol, aminocaproic acid or tranexamic acid) were reported to reduce blood loss to similar extents.

risk for death, kidney failure, congestive heart failure and stroke. 

in secondary exposures- risk of anaphylaxis

CPB weaning

 CROSS CLAMP- good visualisation of surgical fields but may result in myocardial ischaemia without adequate protection


 MYOCARDIAL PRESERVATION
crystalloid cardioplegia
Na 147 K 20 Mg 16 Ca 2 Cl 204 procaine 1 mmol/L
cold

does not prevent ion fluxes and continued influx of Ca, Cl , contributing to depletion of ATP and intracellular calcium overload, thought to be critical in development of myocardial stunning

blood cardioplegia
- most common protective strategy
-however- cold blood cardioplegia- increased viscosity- limits myocardial perfusion
-if warm- may reduce reperfusion injury
-improves o2 carriage (compared to crystalloids)
-improves buffering capacity
-multiple doses may be used
-provides antioxidants

for anterograde (via ascending aorta or aortic sinus, with competent AV, Aortic root pressure of at least 60mmHg for coronary perfusion)

alternative cardioplegia methods (without protection)
- intermittent aortic cross clamp/ induced VF

weaning from CPB
- rewarmed to naso/oeso temp 35-36
-core-periph difference <6 degrees)
-shivering-BAD
-overheting-BAD (>36)

intracardiac procedure- de-airing
epicardial pacing wires to protect against arrhythmias
acid base imbalances, electrolytes
ventilation recommenced
anaesthesia/analgesia/nmba suppplemented
monitors
myocardial support instituted

separation
-stable heart rhythm, warm, all above factors addressed
-venous line partially clamped-heart fills
-pump speed reduced-if BP maintains-->
-venous line fully clamped
-pump stopped when heart is appropriately filled and functioning well. (may need tropes, optimal hr)
-can continue to fill with arterial line  


 causes of failure to wean
poor preop ventricular function
inadequate myocardial protection
prolonged cross clamp time
imperfect surgical repair
electrolyte imbalance
acidosis
arrhythmias