Is the mechanism of re-expansion pulmonary oedema in a heart-lung interaction?

The mechanism of re-expansion pulmonary oedema (Re-PE) is unclear. There are multiple variables in play when evaluating the response to evacuation of pleural fluid. We present an educational case of a critically ill patient admitted for respiratory failure who was fully dependent on ventricular pacing set at a constant rate throughout the episode of Re-PE. The transthoracic echocardiography (TTE) showed an ejection fraction of 38%, moderate mitral regurgitation (MR), mildly dilated right ventricle and moderate pulmonary hypertension. A pleural tap evacuated 850 mL of transudate, which was followed by tachypnoea and deteriorating oxygenation. Another repeat TTE revealed a Re-PE with elevated left ventricular end-diastolic pressure, severe MR, increased pulmonary hypertension and a decrease in stroke volume. There were no parallel changes in ventilation modality, heart rate, fluid therapy and vasopressor dosage. The treatment was initiated with dobutamine. The patient was extubated the next day and was later discharged to the cardiology department.