Effects of Intra-Aortic Balloon Counterpulsation on Parameters of Tissue Oxygenation
Background: To investigate the effects of intra-aortic balloon pump therapy on parameters of global and regional oxygenation in patients undergoing cardiac surgery.
Methods: As part of a large surveillance study in cardiac surgery patients (n = 266) we retrospectively analyzed the course of 28 patients requiring intra-aortic balloon pump therapy. Patients were grouped according to the time point of pump insertion (during weaning from cardiopulmonary bypass: group early intra-aortic balloon pumping (n = 17); after admission to the intensive care unit: group late intra-aortic balloon pumping (n = 9). Haemodynamic and tonometric variables, arterial lactate, and use of catecholamines were measured hourly.
Results: Cardiac index increased in both groups after intra-aortic balloon pump insertion (2.2 +/- 0.5 baseline; 3.4 +/- 0.8 L min-1 m-2 4 h later (group early intra-aortic balloon pumping); 2.8 +/- 0.5 baseline, 3.6 +/- L min-1 m-2 4 h later (group later intra-aortic balloon pumping), each P < 0.05), there were no differences between groups. Arterial lactate values increased in group later intra-aortic balloon pumping after pump insertion to a maximum 2 h later (8.4 +/- 6.1 mmol L-1 baseline; 12.7 +/- 7.4 mmol L-1, P < 0.05), and decreased continuously afterwards. The difference of arterial and gastric CO2 showed a sharp decrease after pump insertion in group later intra-aortic balloon pumping (26.4 +/- 9.8 baseline; 7.0 +/- 11.1 mmHg, P < 0.05). There were no differences between groups. Epinephrine doses were higher in group later intra-aortic balloon pumping (P < 0.05).
Conclusions: Intra-aortic balloon pump therapy improved global and regional splanchnic oxygenation in cardiac surgery patients with low-cardiac-output syndrome. Gastro-intestinal tonometry could provide additional information concerning tissue oxygenation. Patients with later intra-aortic balloon pump insertion needed more catecholamine therapy to achieve similar haemodynamic values.
