Defining indications for selective chest radiography in the first 24 hours after cardiac surgery

In the intensive-care unit (ICU), chest radiographs (CXRs) are frequently obtained routinely for postoperative cardiac surgery patients, despite the fact that the efficacy of routine CXRs is known to be low. We investigated the efficacy and safety of CXRs performed after cardiac surgery for specified indications only.

In this observational cohort study, we prospectively included all patients who underwent conventional major cardiac surgery by median sternotomy in the year 2012. On-demand CXRs could be obtained during the first postoperative period for specified indications only. A routine control CXR was performed on the morning of the first postoperative day for all patients who had not undergone a CXR before that time. The diagnostic and therapeutic efficacy values were calculated for all CXRs. Differences were tested using Fisher's exact test or χ(2) analysis.

A total of 1102 consecutive cardiac surgery patients were included in this study. The diagnostic efficacy of CXRs for major abnormalities was higher for the postoperative on-demand CXRs (n = 301; 27%) than for the routine CXRs taken the morning after surgery (n = 801; 73%) (6.6% vs 2.7%, P = .004). The therapeutic efficacy was higher for the on-demand CXRs, whereas the need for intervention after the next-morning, routine CXRs was limited to 5 patients (4.0% vs 0.6%, P < .001). None of these patients experienced a major adverse event.

Defining clear indications for selective CXRs after cardiac surgery is effective and seems to be safe. This approach may significantly reduce the total number of CXRs performed, and will increase their efficacy.