Hyperbaric oxygen (HBO) therapy for acute carbon monoxide (CO) poisoning is performed after oxygen therapy and breathing therapy. The usefulness of HBO therapy in emergency treatment has been reported. In this study, we examined the effectiveness of HBO for CO poisoning that was performed at our hospital over the past 5 years. Subjects were 23 patients who had HBO therapy for CO poisoning in the period January 2008-November 2013. The male to female ratio of the cases was 14:9 and the mean age was 54.6±20.8 years. The cause was suicide in 39.1% of cases and accident in 60.9%. The mean number of treatments was 5.4±6.8. The atmosphere absolute was 2ATA:2.8ATA=12:11. The ratio of direct conveyance of the patient to our hospital to indirect conveyance of the patient from another hospital was 15:8. The effectiveness of HBO therapy at the time of discharge was 73.9%. However, delayed neuropsychiatric sequelae (DNS) was detected in 3 of the 23 cases of CO poisoning. No correlations were found between elapsed time after CO inhalation and various blood parameters. However, time to start of therapy is important for DNS, and our results suggest that early treatment at a hospital with a hyperbaric chamber is necessary.

Objective: In this study, thermoelastic stress analysis was conducted to clarify the surface stress distribution of a femur in which a BiCONTACT E stem was inserted. The contact sites between the stem and femur were examined to investigate the association with the range of stress distribution.Materials and Methods: BiCONTACT E was set up using two synthetic femurs that mimic the morphology and mechanical properties of living bone. Preoperative planning was performed using three-dimensional imaging software. The synthetic bone was placed in a sample holder. After the stem was implanted into the synthetic bone, computed tomography imaging was performed. The contact sites between the stem and the cortical part of the synthetic bone were examined using the imaging software. Subsequently, thermoelastic stress measurements were performed on the sample.Results: The results of thermoelastic stress analysis indicated a minimum change in the sum of principal stresses [Δ (σ1+σ2)] on the medial side and a maximum change in the sum of principal stresses on the lateral side. Thus, no minimum change was observed in the sum of the principal stresses at the maximum proximal part. It is reasonable to assume that the use of a cementless stem can inevitably lead to bone atrophy in the proximal part of the femur. The contact sites between the stem and femur were also investigated, and the results of the study clearly and quantitatively demonstrated the correlation of the contact sites with a range of stress distributions.Conclusion: The surface stress distribution of a femur, in which a BiCONTACT E stem was inserted, was clarified. The contact sites between the stem and femur were also investigated. Furthermore, the correlation between these results and clinical bone response was investigated in this study.