Location of the pulmonary artery catheter according to West's zones in portable chest X-Ray

Abstract

Aim: to measure the interobserver concordance and the concordance between the antero-posterior and lateral projections relative to the location of the catheter tip in West's zone 3.

Patients: adults admitted to Medical and Surgical Intensive Care Units who required hemodynamic monitoring with a pulmonary artery catheter.

Methodology: following the placement of the pulmonary artery catheter two portable chest X-rays were taken in antero-posterior (AP) and translateral (LAT) projections. The x-rays were randomized and then read by two radiologists who were blind to each other and to the patient. The parameters for the readings were standardized before starting the study.

Results: 32 patients were included. On reading the AP x-ray 8 (25%) of the catheters were located in West's zone 3 and 24 (75%) were not. On the lateral x-ray 12 (38%) of catheters were in zone 3,15 (46%) were not, and 5 cases were not definable. Interobserver concordance on AP x-rays was 88%, on lateral x-rays 73% and on the evaluation of AP and LAT concordance we found 57%.

Conclusions: the concordance between the antero-posterior and translateral projections in order to determine the location of the catheter tip in the pulmonary artery in West's zone 3 is low and and very poor for the interobserver concordance on the translateral x-ray. It is not sufficient, as is customary, to evaluate a Swan-Ganz catheter with an AP x-ray in order to believe the data obtained by its measurements.