ObjectiveTo analyze the postoperative drainage volume and its influencing factors in lumbar posterior surgery.MethodsA total of 158 patients undergoing lumbar posterior surgery in West China Hospital, Sichuan University between October 2018 and June 2019 were retrospectively enrolled in this study. The data about general information and perioperative drainage were collected retrospectively according to recording tables and analyzed by SPSS (version 22) software. The drainage volume was presented with median (lower quartile, upper quartile).ResultsThe final average drainage volume was 360 (200, 650) mL, and the length of time for drainage tube placement was from 9 to187 hours with the median (lower quartile, upper quartile) of 61 (40, 86) hours. The result of multiple linear regression showed that immediate drainage volume when returning to the ward [non-standardized partial regression coefficient (b)=0.268, 95% confidence interval (CI) (0.191, 0.345), P<0.001], length of time for drainage tube placement [b=0.554, 95%CI (0.338, 0.769), P<0.001], intra-operative bleeding volume [b=0.161, 95%CI (0.044, 0.277), P=0.007], and surgical methods [Method 3 as the reference, Method 1: b=0.599, 95%CI (0.369, 0.828), P<0.001; Method 2: b=0.574, 95%CI (0.336, 0.812), P<0.001] were the main factors affecting the final drainage volume.ConclusionsThe final drainage volume of lumbar posterior surgery is so large that it should be paid attention to. It is also necessary to take effective interventions according to different surgical methods, intraoperative bleeding, immediate drainage when returning to the ward, length of time for drainage tube placement, and other different circumstances to reduce the drainage to achieve enhanced recovery after surgery.