Patients in the radiology department may be at increased risk of developing critical instability.

The purpose of this study was to calculate the event rate for in-patients in the Radiology Department (RD) developing instability leading to calls for Medical Emergency Team assistance (MET-RD) compared to general ward (MET-W) patients. A retrospective comparison was done of MET-RD and MET-W calls in 2009 in a U.S. tertiary hospital with a well-established MET system. MET-RD and MET-W event rates represented as MET calls/hour/1000 admissions, adjusted for length of stay (LOS); rates also calculated for RD modalities. There were 31,320 hospital ward admissions had 1,230 MET-W, and among 149,569 radiology admissions there were 56 MET-RD. When adjusted for LOS, the MET-RD event rate was 2 times higher than the MET-W rate (0.48 vs. 0.24 events/hour/1000 admissions). Event rates differed by procedure: computed tomography (CT) had 38% of MET-RDs (event rate 0.89); magnetic resonance imaging (MRI) accounted for 27% (event rate 1.56). Nuclear medicine had 1% of RD admissions but these patients accounted for 5% of MET-RD (event rate 1.53). Interventional radiology (IR) had 6% of RD admissions but 16% of MET-RD (event rate 0.61). While general x-ray comprised 63% of RD admissions, only 11% of MET-RD involved their care (event rate 0.09). In conclusion, the overall MET-RD event rate was twice the MET-W event rate; CT, MRI and IR rates were 3.7-6.5 times higher than on wards. RD patients are at increased risk for a MET call compared to ward patients when the time at risk is considered. Increased surveillance of RD patients is warranted.