An Inadvertent Course of a Central Venous Catheter

A central venous catheter was inadvertently placed into a pulmonary vein in a patient with undiagnosed partial anomalous pulmonary venous return. A post procedure chest X-ray revealed that the catheter tip was in the hilum of the left lung. A blood gas drawn from this misplaced catheter, a preexisting dialysis catheter and an arterial catheter showed different Po2 values of 167 mmHg, 26 mmHg and 98 mmHg respectively. This discrepancy supported our suspicion that the misplaced catheter tip was located in the left side of the heart. To rule out arterial placement we transduced the misplaced catheter. Both pressure and waveform showed venous characteristics, combined with Po2 of 167 mmHg supported the catheter tip being in the left side of the heart. A contrast computed tomography confirmed that the catheter was in the left upper pulmonary vein (fig. 1A).Pulmonary venous anatomy comprises of four veins: right and left superior and inferior veins which individually drain into the left atrium. Partial anomalous pulmonary venous return may result in blood draining into any of the central veins. It is present in 0.4 to 0.7% of individuals and can be associated with atrial septal defects.1 Left sided partial anomalous pulmonary venous return is uncommon.2 In left sided partial anomalous pulmonary venous return, the left pulmonary veins often drain into an anomalous vein that drains into the innominate vein (fig. 1B).If a catheter placed in the left internal jugular courses down and into the left or right lung hilum, a high degree of suspicion should exist for partial anomalous pulmonary venous return. Ideally the catheter should be promptly removed to prevent catheter related blood clots, pulmonary emboli and strokes.3 If the catheter is needed, an air bubble filter use would be prudent.Sending simultaneous blood samples from the misplaced central and other confirmed central, arterial catheters may aid in the diagnosis of partial anomalous pulmonary venous return. In a situation where the left internal jugular is the only central venous access available, the central line can be placed or repositioned under fluoroscopic guidance. In our patient the catheter was never used and removed after the computed tomography scan results were reported. The central line was subsequently replaced under fluoroscopy.