Analysis of perioperative blood loss of posterior lumbar interbody fusion on lumbar spondylolisthesis in patients with rheumatoid arthritis

Objective: To compare the intraoperative blood loss, postoperative drainage and hidden blood loss (HBL) in lumbar posterior lumbar interbody fusion (PLIF) in patients with and without rheumatoid arthritis (RA), and analyze the relevant factors of HBL in RA patients. Methods: Fifty patients with RA (RA group) and 73 patients without RA (NRA group) treated in the Heze Municipal Hospital from January 2014 to April 2019 were enrolled in this study. The basic information, RA information, operation and related blood loss indicators in the two groups were compared. The intraoperative blood loss, postoperative drainage and HBL were the main results. The secondary results were operation time, preoperative and postoperative hematocrit (Hct) and hemoglobin (Hb) and their variation values, cases of anemia before and after surgery, number of new anemia after surgery, autologous blood and allogeneic blood transfusion, etc. The correlation factors of HBL in RA group were analyzed by multi-linear regression model. Results: There were 9 males and 41 females with a mean age of (62±7) years in RA group; and 11 males and 62 females with a mean age of (64±9) years in NRA group. The course of disease in RA group was (14.4±11.2) years, the most common anti-rheumatism drug (DMARDs) were single-drug and combined oral. There was no significant differences between the two groups in the number of vertebral bow screws and intervertebral fusion device. The incidence of surgical complications was comparable between the two groups. Differences between the two groups in total blood loss (TBL), intraoperative blood loss, and postoperative drainage were not statistically significant ((693±315) ml vs (630±365) ml, (454±373) ml vs (414±375) ml and (653±376) ml vs (675±400) ml, t=1.072, 0.388, -0.189, all P>0.05), while the HBL and the percentage of HBL in TBL were lower in the NRA group (t=6.157, 2.965, both P 0.05). There was no significant difference in anemia and exacerbation of anemia after surgery, allogeneic blood transfusion and the operation duration between the two groups (all P>0.05). A multi-linear regression analysis of HBL showed that higher RA's Steinbrocker grading, did not take DMARDS, Hb changes and infusion of allogeneic blood were independently correlated to HBL (β=0.363, -0.272, 0.210, 1.204, all P<0.05). Conclusions: There is no difference in TBL, intraoperative blood loss, postoperative drainage and operation duration between the RA and NRA group, while HBL and the proportion of HBL in the TBL are higher in the RA group. The RA group has higher Steinbrocker rating, no DMRDs and more Hb changes.