OBJECTIVE: Systemic effects of carbon dioxide (CO(2)) insufflation during left-sided cardiac surgery were evaluated in a prospective randomized study, with regard to acid-base status, gas exchange, cerebral hemodynamics, and red blood cell morphology. METHODS: Twenty patients undergoing elective left-sided cardiac surgery were randomized to de-airing procedure either by CO(2) insufflation technique (CO(2) group, n = 10) or by Lund technique without CO(2) insufflation (Lund group, n = 10). Groups underwent assessment of acid-base status by intermittent arterial blood gases and in-line blood gas monitoring. Capnography was used to determine volume of CO(2) produced. Cerebral hemodynamics was measured by transcranial Doppler sonography and near-infrared spectroscopy. Red cell morphology from cardiotomy suction and vent tubing was studied by scanning electron microscopy. RESULTS: Patients in the CO(2) group consequently developed significantly higher levels of hypercapnia with a concomitant increase in the volume of CO(2) produced despite significantly higher oxygenator gas flows compared with the Lund group. Effects on cerebral hemodynamics were observed in the CO(2) group with significantly higher blood flow velocities in the middle cerebral artery and higher regional cerebral saturation. Red blood cell damage was observed in the CO(2) group by scanning electron microscopy (97% in CO(2) group vs 18% in Lund group). CONCLUSIONS: Insufflation of CO(2) into the cardiothoracic wound cavity during left-sided cardiac surgery can induce hypercapnic acidosis and increased cerebral blood flow and local blood cell damage. These systemic effects should be monitored by in-line capnography and acid-base measurements for early and effective correction by increase in gas flows to the oxygenator.
- Cardiac and Cardiovascular Systems