A comparison between two radiological criteria for verifying tip location of central venous catheters.

Introduction: Current guidelines recommend intraprocedural methods-such as Intra-Cavitary ECG (IC-ECG) and echocardiography-for verifying the location of the tip of central venous catheters. Nonetheless, there are clinical conditions which may require to verify tip location by less accurate methods such as Chest X-Ray (CXR). We have compared the feasibility and accuracy of two radiological methods for tip location-the Sweet Spot Criterion (SSC) and the Carina Criterion (CC)-using IC-ECG as reference.

Methods: In this retrospective multicenter study, we reviewed the radiology databases of three hospitals, examining all CXRs performed on patients after insertion of Peripherally Inserted Central Catheters (PICCs), as long as the tip location had been successfully performed during the procedure by IC-ECG. Tip location was verified using SSC and CC, comparing the two methods in terms of feasibility and accuracy.

Results: We reviewed the CXR of 1116 PICCs successfully inserted by IC-ECG. CC was not feasible in 0.5% (impossible visualization of the carina) and difficult in 1.5%; in 97.7% of cases, the position of the tip was adequate (1-5 cm below the carina), in 0.6% too high (<1 cm), in 1.2% too low (6-9 cm). On the other hand, because of unclear visualization of radiological landmarks, SSC was not feasible in 0.9% and difficult in 10.5%; though, according to SSC the tip location was always acceptable (in 94.2% the tip was in the middle of the spot, in 2.5% close to the superior border, and in 2.3% close to the inferior border); no tip was visualized outside of the spot.

Conclusion: CC and SSC were similar in terms of feasibility (99.5% vs 99.1%) and accuracy (98.1% vs 100%), though CC was subjectively perceived to be easier and more rapid to perform.