Total laboratory automation can help eliminate the laboratory as a factor in emergency department length of stay

We obtained data on laboratory turnaround time (TAT) and emergency department (ED) length of stay (LOS). We correlated potassium test TAT outlier percentage (TAT-OP) with ED LOS and found that for each outlier percentage (potassium result > 40 minutes), a projected impact on ED LOS was approximately 2.8 additional minutes (ED LOS = 2.79 TAT-OP + 78.77). To address this issue, we began implementation of a totally automated chemistry system to decrease TAT-OPs. Our TAT means did not change substantially with automation (potassium, 28 to 27 minutes); however, TAT-OPs decreased substantially (potassium, 18% to 5%). Preautomation average ED LOS correlated best with the TAT-OP (r(2) = 0.98; P = .01), but this relationship weakened substantially after automation (r(2) = 0.29; P > .05), suggesting the laboratory was no longer a factor in ED LOS. The postautomation ED LOS correlated best with ED patient volume (r(2) = 0.88; P = .06). Although laboratories have focused on TAT means for performance assessment, our study suggests TAT-OPs are more clinically relevant benchmarks. Furthermore, our findings suggest that total laboratory automation can effectively improve overall laboratory service reliability and help eliminate the laboratory as a factor in ED LOS.