During cardiopulmonary bypass (MVR+CABG) blood was seen in the water lines that connect the heater cooler unit to the oxygenator’s heat exchanger. This obviously suggests a leak in the heat exchanger and the patients’ blood and water could be potentially mixing. The water lines were immediately switched off and disconnected, and the consultant surgeon informed.
The recommended procedure is to change out the oxygenator following heat exchanger leak. However, the consultant cardiac surgeon felt that this was not a safe option at the time as the oxygenator was still working, so we remained on bypass. The cross clamp was removed and the patient was rewarmed from 28°C to 34°C using the separate heat exchanger on the cardioplegia circuit and two fluid warmers donated by the anaesthetic team. Once the patient reached 34°C, the patient was ventilated and bypass was terminated and the oxygenator replaced with a new one. Bypass was re-commenced and the patient fully rewarmed. Bypass was discontinued and the patient was stable. It should be noted that a full heat exchanger leak test was performed before the bypass circuit was primed and no fault was detected (water circulated at 37oC for 5mins prior to adding prime solution, no pressure test).