The sedative effect of high spinal anaesthesia is greater in older patients than in younger patients, with an increase in respiratory instability.

Background: Therapy with glucocorticoids often results in bone loss and glucocorticoidinduced osteoporosis. However, the relationship between epidural steroid injection (ESI), bone mineral density (BMD), and vertebral fracture remains to be determined. Objective: To establish a relationship between ESI, BMD, and vertebral fracture in postmenopausal women with low back pain. Study Design: This study was a retrospective, nonblinded, cross-sectional clinical study. Setting: University-based pain management center. Methods: We reviewed the medical records of postmenopausal women with low back pain who were treated with ESI. A total of 352 postmenopausal women were divided into 2 groups. Group 1 consisted of patients without fracture and Group 2 consisted of those with fractures. The results of BMD measurements, as well as any fragility fractures, the anatomical site involved, and the treatment administered, were also recorded. BMD was measured in the lumbar spine, femoral neck, and total femur after the treatment. Results: Of the 352 patients, 218 (62%) had no fractures while 134 (38%) sustained a fracture. The age was significantly higher among patients who sustained fractures, and BMD at the lumbar spine, total femur, and femoral neck regions was significantly lower among patients who sustained fractures. In each region, the prevalence of osteoporosis was significantly higher in patients with fracture than in patients without fracture (all P < 0.05). Age, height, and weight were associated with low BMD. However, our study showed no consistent correlation between BMD and the mean number of ESIs, mean total dose of glucocorticoids, or mean duration of ESIs. Limitations: First, this study is limited by the fact that it was retrospective. Second, the number of cases receiving very frequent, high-dose glucocorticoid injections was very small. Conclusions: Older age and lower BMD were associated with osteoporotic fracture in postmenopausal women treated for low back pain with ESI. The ESIs were not associated with low BMD or fracture. Key words: Bone mineral density, epidural steroid injection, fracture, glucocorticoids, low back pain, postmenopause.

Patient-controlled analgesia (PCA) provides excellent pain control and high stability, thereby minimizing the incidence of adverse effects. However, one of our patients experienced respiratory depression and hypotension within 30 minutes of initiation of PCA therapy. We discovered that machine malfunction caused continuous activation of the PCA button, resulting in a drug overdose. The PCA machine was sent to the manufacturer, who found an electrical short in the PCA button. All PCA units of the same make and model were immediately removed from hospitals and replaced with redesigned units without defects in the PCA button. We have used the improved machines without any problems. The purpose of this report is to raise awareness of this type of malfunction in PCA units in order to help prevent adverse events in the future.