Peripheral tissue oxygenation during standard CPB and miniaturized CPB (direct oxymetric tissue perfusion monitoring study).

AIM: The aim of this study was to compare the impact of standard cardiopulmonary bypass (CPB) with mini CPB on peripheral tissue perfusion. METHODS: 24 patients with ischemic heart disease scheduled for CPB were randomised to two groups: Group A (12 patients, standard CPB) and Group B (12 patients, mini CPB). Oxygen tension was measured with an optical multiparametric sensor inserted into the patient's deltoid muscle. RESULTS: Lower priming in Group B (870 ± 221 mL) vs. Group A (1502 ± 48 mL) and significantly reduced hemodilution during mini CPB (Group B 25.3 ± 1.1% vs. Group A 30.1 ± 2.3%) were recorded. Higher and continuous blood flow during perfusion was analysed in Group A (4.58 ± 0.34 L.min(-1)) and lower than calculated blood flow was found in Group B (3.49 ± 0.51 L.min(-1) vs. 4.66 ± 0.38 L.min(-1)). There was a direct correlation between mean arterial pressure (MAP) and ptO2 in Group A during CPB and a direct correlation between pump blood flow and MAP during CPB in Group B. Higher levels of ptO2 during CPB and surgery after CPB in comparison with initial levels were found in Group B. Decreased ptO2 levels after surgery were found in both groups. CONCLUSION: Mini CPB enables perfusion with a relatively low flow. The results of this study suggest that a flow decrease in mini CPB is well tolerated by the organism.

No clear clinical benefit of using mini-invasive extracorporeal circulation in coronary artery bypass grafting in low-risk patients.

BACKGROUND: Current research is engaged in innovative technologies of extracorporeal circulation (ECC) systems in an effort to eliminate negative effects. Some studies have shown that, due to the complexity of technical settings of mini-ECC, they invoke a weaker immune response compared to classic ECC. The clinical benefits of using these systems have not been clearly proven yet. METHODS: A group of 54 patients who were indicated for elective coronary surgery were randomised into two groups - Group A (patients operated on using classic ECC - open modification) and Group B (patients operated on using mini-ECC). The concentrations of IL-6, PMN elastase and MCP-1 in both groups were monitored per- and postoperatively, along with the postoperative clinical course. RESULTS: The groups did not differ in the basic pre- and peroperative characteristics. We recorded a lower priming for mini-ECC (p < 0.001) and significantly reduced hemodilution during ECC. There were no differences in the clinical outcome in either group. Serum concentrations of monitored markers of immune reaction towards ECC showed higher activity during standard ECC. CONCLUSION: New technologies used in mini-systems have proven to lower activation of the immune system, which can be monitored using kinetics of proinflammatory mediators. In spite of these comparable laboratory results, we did not find differences in short-term clinical results when comparing both these groups of low-risk patients.

Use of two parallel oxygenators in a very large patient (2.76 m2) for an acute "A" dissecting aortic aneurysm repair.

The very large patient (weight 142 kg, height 197 cm, body surface 2.76 m2) was referred to acute operation with dissecting type A ascending aortic aneurysm. The calculated blood flow was 6.63 l/min. To anticipate potential difficulties with perfusion and oxygenation two oxygenators connected in parallel were incorporated into the circuit. Bentall procedure with ACB to the RCA was performed. The perfusion was uneventful. Bypass time was 259 minutes, cross clamp time 141 minutes, circulatory arrest 7 minutes. The highest oxygenators gas flow was 2.6 l/min with maximum FiO2 0.42. The use of two in parallel connected oxygenators is a very effective, easy and safe method in such extreme perfusions, offering to the perfusionist a great reserve of oxygenator output.