Assessment of chemical asphyxia caused by toxic gases generated from rigid polyurethane foam (RPUF) fires.

Rigid polyurethane foam (RPUF) is widely used for thermal and sound insulation owing to their low thermal conductivity and light weight. However, they have serious disadvantages, including flammability and toxic gas generation, which can cause chemical asphyxia during a fire. Carbon monoxide (CO) and hydrogen cyanide (HCN) are representative toxic gases formed by incomplete combustion and HCN, in particular, is closely related to polyurethane product fires. In this study, the risk of inhalation of toxic gases such as CO, HCN and NO2 during RPUF fires was demonstrated convincingly through the analysis of carboxyhemoglobin (COHb), cyanide (CN-) and methemoglobin (MetHb) in the postmortem blood samples of 38 victims of RPUF fires. To better understand the toxic gas poisoning and chemical asphyxia, we classified all cases into two groups based on the extent of injuries and location where the victim was found. Mean concentrations of COHb and cyanide in group 1 without injuries were approximately two times higher than in group 2 with severe injuries, while concentrations of free MetHb showing possibility of NO2 inhalation were approximately six times lower than in group 2. Furthermore, we presumed concentrations of cyanide at the time of death and five cases showed the possibility of cyanide poisoning.

The Epidemiology and Trends of Primary Total Ankle Arthroplasty and Revision Procedure in Korea between 2007 and 2017.

BACKGROUND: The aim of this study was to investigate the surgical trends of primary total ankle arthroplasty (TAA) and revision procedure in Korea from 2007 to 2017 using national population-based data. METHODS: We reviewed the National Health Insurance data of Korea from 2007 to 2017. The data included diagnosis codes, procedure codes, prescriptions, medical costs, and other demographic data. Trends of primary diagnosis for primary TAA were evaluated. Annual trends and incidences per 100,000 person-years of primary TAA and revision procedures as well as compound annual growth rate (CAGR) during the study period were analysed. Surgical trends according to patients' age, hospital grades, and insurance systems were also evaluated. RESULTS: Primary diagnosis for primary TAA was mostly degenerative arthritis (6,501 cases; 90.5%). From 2007 to 2017, the total number of cases of primary TAA and revision procedures was 7,183 and 585, respectively. The number of cases in 2007 of primary TAA was 313; there were no cases of revision. The number of cases in 2017 of primary TAA were 986 and of revision were 108. The CAGR during this period was 28.6% for primary TAA and 44.6% for revision procedures. Incidences per 100,000 person-years in 2017 were 1.91 for primary TAA and 0.21 for revision procedures. The average cost paid by patients themselves was USD 813 (19%) and by the National Health Insurance Service was USD 3,480 (81%). CONCLUSION: The incidence of primary TAA and revision procedures steadily increases in Korea during the 11-year study period.

National Trends in Surgery for Rotator Cuff Disease in Korea.

The objective of this study was to investigate the national trends in rotator cuff surgery in Korea and analyze hospital type-specific trends. We analyzed a nationwide database acquired from the Korean Health Insurance Review and Assessment Service (HIRA) from 2007 to 2015. International Classification of Diseases, 10th revision (ICD-10) codes, procedure codes, and arthroscopic device code were used to identify patients who underwent surgical treatment for rotator cuff disease. A total of 383,719 cases of rotator cuff surgeries were performed from 2007 to 2015. The mean annual percentage change in the age-adjusted rate of rotator cuff surgery per population of 100,000 persons rapidly increased from 2007 to 2012 (53.3%, P < 0.001), while that between 2012 to 2015 remained steady (2.3%, P = 0.34). The proportion of arthroscopic surgery among all rotator cuff surgeries steadily rose from 89.9% in 2007 to 96.8% in 2015 (P < 0.001). In terms of hospital types, the rate of rotator cuff surgery increased to the greatest degree in hospitals with 30-100 inpatient beds, and isolated acromioplasty procedure accounted for a larger proportion of the rotator cuff surgeries in small hospitals and clinics compared to large hospitals. Overall, our findings indicate that cases of rotator cuff surgery have increased rapidly recently in Korea, of which arthroscopic surgeries account for the greatest proportion. While rotator cuff surgery is a popular procedure that is commonly performed even in small hospitals, there was a difference in the component ratio of the procedure code in accordance with hospital type.

Cost-effectiveness Analysis of Existing Pedicle Screws Reusing Technique in Extension Revision Operation for Adjacent Segmental Stenosis After Lumbar Posterolateral Fusion.

STUDY DESIGN: Retrospective case-control study. OBJECTIVE: A cost-effectiveness analysis was performed by comparing patients who received extension revision operations for adjacent segment disease (ASD) reusing the pedicle screws extracted from fused segments with patients who received conventional surgery. SUMMARY OF BACKGROUND DATA: ASD often required extension revision surgery, and during extension surgery, pedicle screws may be reused by extracting from the fused segments of primary surgery. METHODS: Study examined 37 patients who received extension revision surgery for ASD from January 2003 to December 2013. For the fixation of extended segments during revision operation, in 16 cases the pedicle screws extracted from fused segments were reused (group R), and in 21 cases new pedicle screws were used (group C) as a conventional method. Clinical outcomes were evaluated by means of visual analog scale scores for lumbago and leg pain, and the Korean Oswestry Disability Index. Radiologic outcomes were evaluated from the extent of bone union. The total operating costs in the two groups were compared. RESULTS: Visual analog scale scores for lumbago and leg pain, and the Korean Oswestry Disability Index measured at final follow-up averaged 3.6 and 3.8, and 19.9 in group R, and 3.8 and 3.1, and 21.1 in group C, respectively (P = 0.280, P = 0.387, P = 0.751). For radiologic outcomes, there was one case of nonunion in each group. The cost of surgery was 5332 US dollars in group R, and 6109 US dollars in group C, respectively (P = 0.036). CONCLUSION: Reusing pedicle screws extracted from the fused segments during extension revision operation for ASD can reduce the cost of surgery, and achieves clinical and radiological results similar to those of the conventional operation. LEVEL OF EVIDENCE: 4.