Although pericardial effusions (PE) and pleural effusions (PLE) may lead to life-threatening respiratory and circulatory deterioration following open heart surgery the postoperative frequency is not fully recognized. The diagnosis is typically based on ultrasonography, X-ray or computer tomography and often disclosed when circulatory collapse is evident. Point-of-care (POC) ultrasonography protocols constitute a noninvasive evaluation of the cardiopulmonary status. We hypothesized that POC ultrasonography could diagnose unknown PE and PLE.