STUDY DESIGN: A retrospective cohort study. PURPOSE: To investigate the risk factors for postoperative delirium after spine surgery, excluding older age, which has already been established as a strong risk factor. OVERVIEW OF LITERATURE: More than 30 risk factors have been reported for delirium after spine surgery, making it challenging to identify which factors should be prioritized. We hypothesized that risk factors could not be prioritized to date because the factor of older age is very strong and influenced other factors. To eliminate the influence of older age, we performed an age-matched group comparison analysis for the investigation of other risk factors. METHODS: This study involved 532 patients who underwent spine surgery. Two patients of the same age without delirium (delirium negative group) were matched to each patient with delirium (delirium positive group). Differences in suspected risk factors for post-operative delirium between the two groups identified from previous reports were analyzed using univariate analysis. Multivariate analysis was performed for factors that showed a significant difference between the two groups in the univariate analysis. RESULTS: Fifty-nine (11.1%) of 532 patients developed postoperative delirium after spine surgery. Large amounts of intraoperative bleeding, low preoperative concentration of serum Na, high postoperative (day after surgery) serum level of C-reactive protein, low hematocrit level, low concentration of albumin, and high body temperature were detected as significant risk factors in the univariate analysis. Large amounts of intraoperative bleeding remained a risk factor for postoperative delirium in the multivariate analysis. CONCLUSIONS: We should pay attention to and take precautions against the occurrence of postoperative delirium after spine surgery in patients of older age or those who experience severe intraoperative bleeding.
Body Temperature ; C-Reactive Protein ; Cohort Studies ; Delirium ; Hematocrit ; Hemorrhage ; Humans ; Multivariate Analysis ; Retrospective Studies ; Risk Factors ; Spine

There have so far been no studies examining the physical fitness and physical activity (PA), measured using objective measures, in homebound elderly people. The purpose of this study was to examine physical fitness levels and PA patterns and evaluate their relationships in homebound elderly people. In 2004, a total of 3964 community-dwelling elderly aged 65 years and over participated in a base line survey. The subject data were directly collected by in-home interviewer. Subjects were defined as being homebound if they went outdoors less than once a week. However, the subjects who could not go out without assistance due to sickness and/or disability were excluded from the analysis. In 2005, 38 homebound (22 men, 16 women) and 70 non-homebound (33 men, 37 women) older adults who participated in the base line survey were selected. Measurements of physical fitness levels and PA patterns measured using an accelerometer, were taken in 2005. The total steps per day did not significantly differ between homebound and non-homebound men and women. The time spent in 1.8 METs activity (corresponding to activity level 1 of the accelerometer) was significantly higher in women than in men for non-homebound and homebound, respectively. The time spent in lower-, moderate-, and high-intensity PA did not significantly differ between homebound and non-homebound men and women, respectively. Handgrip strength, knee extensor strength, leg extensor power, stepping and maximum walking speed were significantly higher in non-homebound than in homebound men and women. These results suggest that the physical fitness levels of homebound were lower than those of non-homebound, but no difference was observed in the PA levels between homebound and non-homebound.