【INTRODUCTION】The importance of predicting postoperative complications is not controversial, and there is a wide variety of methods to assess it. Surgical Apgar Score (SAS), described by Gawande et al. in 2007, has attracted much attention for its usefulness. SASis a 10-point scoring system consisting of three intraoperative factors: estimated blood loss, lowest mean arterial pressure, and lowest heart rate. Low scores for each intraoperative factor indicate clinical deterioration, and it has effectively predicted the prognosis of major complications in surgery, including spinal disease. However, the usefulness of SAS has not been evaluated if limited to posterior lumbar interbody fusion (PLIF). The purpose of this study was to investigate the relationship between SAS score and the postoperative complications and to investigate whether SAS can predict the occurrence of postoperative complications in PLIFs.
【METHODS】This research was a retrospective clinical study. All patients who underwent a PLIF with single-level, planned surgery at a single institute from 2010 to 2022 were included. Multilevel, revision, and unplanned PLIFs were excluded. Operative notes and anesthesia records were reviewed for estimated blood loss, lowest mean arterial pressure, and lowest heart rate. The patients were divided into four groups by SAS (0-4, 5-6, 7-8, and 9-10), and the incidence of complications in each group was examined. The Fisher’s test was used as the statistical method. The receiver operating characteristic (ROC) analysis was used to evaluate the discriminatory power of SAS.
【RESULTS】A total of 815 patients met the study criteria. 33 serious complications were reported, and no deaths occurred. Major complications were reported for 33 patients. The incident rate of complications was 53.8% with SAS 0-4, 7% with SAS 5-6, 2.6% with SAS 7-8 and 0% with SAS 9-10, respectively. There were no reported deaths. The complication rates were predominantly higher for SAS 0-4 (p < 0.001) and SAS 5-6 (p = 0.0179) compared to SAS 7-8. Peripheral vascular disease (p = 0.01), moderate or severe renal disease (p = <0.0001), diabetes with end organ damage (p = 0.01) and lymphoma (p = 0.02) were significantly more common in patients with major complications. The SAS and complications ROC reported an area under the curve of 0.73.
【DISCUSSION】The data of this study showed that a lower SAS was associated with a predominantly statistically significantly higher incidence of postoperative complications, and that SAS can predict postoperative complications in PLIFs.