1.
Cardioplegic solutions provide the opportunity to operate on a nonbeating heart and to protect the heart against ischemic injury during cardiac surgery. The components of these solutions are constantly being modified in an effort to find the optimal
solution. We studied the effects of colloidal volume replacers such as
dextran, HES and
gelatin as an isocolloidoosmotic addition to
St. Thomas Hospital cardioplegic solution in
ischemia-reperfusion injury of isolated rat hearts. 2. In the control group, after a stabilization period of 20 min, the hearts were arrested with
St. Thomas Hospital cardioplegic solution for 3 min, then subjected to 30 min of global
ischemia. Hearts then were reperfused for 10 min. In the experimental groups, the protocol was the same, but either HES 200/0.5 (50 g/L), modified fluid
gelatin (30 g/l) or
dextran 70 (25 g/L) were added to the St. Thomas Hospital
solution. 3. All hearts were compared for their preischemic and postischemic contractility, heart rate, contractility rate product, coronary flow,
lactate dehydrogenase,
creatine phosphokinase enzyme leakage and wet/dry weight ratio. 4. All groups had similar contractility (for control, HES,
gelatin and
dextran groups the values at minute 10 of reperfusion were 59+/-9, 56+/-11%, 61+/-14%, 49+/-14% of initial values [P>0.05, respectively]) and
enzyme leakage (
lactate dehydrogenase 4.1+/-1.0, 8.1+/-1.5, 5.8+/-1.4, 3.7+/-1.2 [P>0.05] and for
creatine phosphokinase 3.9+/-2.5, 6.4+/-3.7, 5.5+/-1.3, 5.5+/-0.8, P>0.05] IU xmin(-1) x g dry tissue(-1) in the reperfusion period, respectively) results as compared with the control group. 5. The addition of isocolloidoosmotic
colloids to the
cardioplegic solution did not appear to enhance the effectiveness of the
crystalloid St. Thomas Hospital cardioplegic solution. If a
colloid is to be chosen as a plasma replacer or an additive to priming
solution in the
preoperative period, or during open-heart surgery, it should be modified fluid
gelatin-for no sign of cardiodepression was determined with the use of this agent.