Old Age Is Associated With Increased Surgical Drain Output After Lumbar Surgery For Degenerative Disease

Employing a drain or not always put surgeons in a dilemma. Few studies have evaluated the associated factors of surgical drains after lumbar posterior decompression and instrumented fusion. The aim of this study was to record the characteristics of postoperative drain output, and tried to identify possible risk factors that are independently associated with it. From January 2014 to March 2017, patients undergoing posterior lumbar interbody fusion were included in our study. All patients underwent single-or multiple-level transforaminal lumbar interbody fusion (TLIF) or posterior lumbar interbody fusion (PLIF). The volume of drain output was measured. Variable were collected from demographic data, lab test and surgical information. Both univariate and multivariate analysis were used to detect factors associated with greater drain output. Besides, correlations between the potential variables and volume of drain output were also analyzed. A total of 429 patients were included in this study. Patients with drain output greater than 240 ml drain output were ascribed to case group, and other patients were in control group. The operative time was not correlated with volume of drain output (r = 0.471; P = 0.29), but age was positively correlated with postoperative drain output (r = 0.269; P < 0.001). Multivariate logistic analysis showed that age >= 55 years (odds ratio [OR], 2.860; 95% confidence interval [CI], 1.164-6.847) and multiple levels fused (OR, 1.359; 95% CI, 1.680-6.432) were two significant independent factors that are associated with greater drain output after lumbar spine surgery (P < 0.05). The present analysis demonstrated that age and number of levels are two factors that are associated with volume of postoperative drain output. Patients with these factors should be informed of the possibility of increased drain output, and routine blood test should be performed after surgery in case of the incidence of low hemoglobin.