Decreased blood pressure associated with in-vehicle exposure to carbon monoxide in Korean volunteers.

BACKGROUND: Carbon monoxide (CO) is one of the primary components of emissions from light-duty vehicles, and reportedly comprises 77% of all pollutants emitted in terms of concentration. Exposure to CO aggravates cardiovascular disease and causes other health disorders. The study was aimed to assess the negative effects by injecting different amounts of CO concentration directly to human volunteers boarding in the car. METHODS: Human volunteers were exposed to CO concentrations of 0, 33.2, and 72.4 ppm, respectively during the first test and 0, 30.3, and 48.8 ppm respectively during the second test while seated in the car. The volunteers were exposed to each concentration for approximately 45 min. After exposure, blood pressure measurement, blood collection (carboxyhemoglobin [COHb] analysis), medical interview, echocardiography test, and cognitive reaction test were performed. RESULT: In patients who were exposed to a mean concentration of CO for 72.4 ± 1.4 ppm during the first exposure test and 48.8 ± 3.7 ppm during the second exposure test, the COHb level exceeded 2%. Moreover, the diastolic blood pressure was decreased while increasing in CO concentration after exposure. The medical interview findings showed that the degree of fatigue was increased and the degree of concentration was reduced when the exposed concentration of CO was increased. CONCLUSION: Although the study had a limited sample size, we found that even a low concentration of CO flowing into a car could have a negative influence on human health, such as change of blood pressure and degree of fatigue.

Types of household humidifier disinfectant and associated risk of lung injury (HDLI) in South Korea.

From 2002 through 2015, hundreds of people died of fatal lung injuries associated with the use of humidifier disinfectants (HDs) in Korea. Several chemical disinfectants used for household humidifiers were later clinically confirmed to cause HD-associated lung injury (HDLI). The aim of this study is to evaluate the registered lung disease cases and to compare the distribution of HDLI patients, including deaths, by HD use characteristics including types of HD and HD brands categorized by age group. A total of 530 registered were clinically examined through two rounds of investigations conducted from July 2013 until April 2015. Information on HD use was obtained from a structured questionnaire and home investigations. Approximately one-half of the patients (n=221) were clinically confirmed to be associated with the use of HDs. Pregnant women (n=35, 16%) and pre-school children≤6years old (n=128, 58%) accounted for most of the HD-associated lung injury patients (n=163, 74%). Sixty-seven percent of HDLI patients developed HDLI after less than one year of HD use. HD products containing polyhexamethylene guanidine phosphate (PHMG) were the most frequently used among confirmed HDLI patients (n=123, 55.7%), followed by oligo (2-(2-ethoxy) ethoxyethyl guanidinium (PGH) (n=24, 10.9%) and a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) (n=3, 1.4%). Other HDs did not appear to be linked to HDLI. The majority of the HDLI patients (n=85, 38.5%) was found to use only Oxy Saksak® products containing PHMG. The development of HDLI was clinically found to be associated with the use of several HD products containing PHMG and PGH, and to lesser extent, CMIT/MIT.

Subsidence of polyetheretherketone cage after minimally invasive transforaminal lumbar interbody fusion.

STUDY DESIGN: A retrospective case series. OBJECTIVE: The aim of this study was to determine the rate of cage subsidence after minimally invasive transforaminal lumbar interbody fusion (MITLIF) conducted using a polyetheretherketone (PEEK) cage, and to identify associated risk factors. SUMMARY OF BACKGROUND DATA: Although various rates of cage subsidence after lumbar interbody fusion have been reported, few studies have addressed subsidence rate after MITLIF using PEEK cage. METHODS: A total of 104 consecutive patients who had undergone MITLIF using a PEEK cage with a minimum follow-up of 2 years were included in this study. Cage subsidence was defined to have occurred when a cage was observed to sink into an adjacent vertebral body by ≥2 mm on the postoperative or serial follow-up lateral radiographs. The demographic variables considered to affect cage subsidence were the following: age, sex, body mass index, bone mineral density, diagnosis, number of fusion segment, and the quality/quantity of back muscle, and the cage-related variables considered were: level of fusion, intervertebral angle, cage size, cage position, and postoperative distraction of disc height. Logistic regression analysis was conducted to explore relations between these variables and cage subsidence. RESULTS: : For the 122 cages inserted, the rate of cage subsidence was 14.8% (18 cages), and cage subsidence occurred within 7.2±8.5 (1-25) months of surgery. The odds ratios for factors found to significantly increase the risk of cage subsidence were; 1.950 (95% confidence interval, 1.002-4.224) for L5-S1 level, and 1.018 (95% confidence interval, 1.000-1.066) for anterior cage position. CONCLUSIONS: The rate of PEEK cage subsidence after MITLIF was relatively low. End-plate manipulation and cage insertion during MITLIF were not influenced by a small operation window.

Anterior operation for unstable thoracolumbar and lumbar burst fractures: tricortical autogenous iliac bone versus titanium mesh cage.

STUDY DESIGN: We retrospectively compared 25 cases that used the autogenous iliac bone grafting with 18 cases that used a titanium mesh cage for reconstruction of the vertebral body. OBJECTIVE: To analyze clinical and radiographic results of the autogenous iliac bone and a titanium mesh cage used to reconstruct the vertebral body. SUMMARY OF BACKGROUND DATA: Grafting of the autogenous iliac bone as a strut bone has been traditionally applied for reconstruction of the spine using anterior approach. Although grafting the autogenous iliac bone as a strut bone achieves a high bone fusion rate, it has reported complications in the donor site. For this reason, bone fusion with a mesh cage has been introduced. METHODS: Between March 2000 and December 2010, 43 cases that underwent decompression and instrumented fusion for unstable burst fractures using the anterior approach were enrolled. Levels of injury were T12 in 8 cases, L1 in 19 cases, L2 in 11 cases, and L3 in 5 cases. The mean follow-up period was 64.5 months (range, 14-129 mo). RESULTS: The local kyphotic angle in the group that used the tricortical autogenous iliac bone (group A) was measured 24.81±2.27 degrees preoperatively and 4.95±0.61 degrees at the last follow-up. The angle in the group that used a titanium mesh cage (group B) was 25.21±1.55 degrees preoperatively and 3.9±0.43 degrees at the last follow-up. Both groups obtained bone fusion of grade I and II by Bridwell fusion criteria. The operation site visual analog scale and Korean Oswestry disability index did not differ significantly between 2 groups. Donor site visual analog scale and the operation time was significantly in favor of group B (P<0.05). CONCLUSIONS: Titanium mesh cage filled with the autogenous cancellous bone shortened operation time and reduced the risk of complications in the donor site compared with the group that used the tricortical iliac bone.

Chronic pure radiculopathy in patient with organizing epidural hematoma around C8 nerve root.

Spontaneously occurring spinal epidural hematomas are uncommon clinical findings, and the chronic form is the rarest and its most frequent location is the lumbar spine. Pure radicular involvement is far less frequent than myelopathy. We report a case of progressive radiculopathy in a 52-year-old man with spontaneously occurring cervical epidural hematoma (SCEH). The patient had left hand weakness and numbness for 4 months. MRI scan showed small space-occupying lesion around left 8th cervical nerve root. After surgery we confirmed chronic organizing epidural hematoma. To the best of our knowledge, this is the second reported case in the worldwide literature of pure radiculopathy in a patient with chronic SCEH.

Factors affecting the accurate placement of percutaneous pedicle screws during minimally invasive transforaminal lumbar interbody fusion.

We retrospectively evaluated 488 percutaneous pedicle screws in 110 consecutive patients that had undergone minimally invasive transforaminal lumbar interbody fusion (MITLIF) to determine the incidence of pedicle screw misplacement and its relevant risk factors. Screw placements were classified based on postoperative computed tomographic findings as "correct", "cortical encroachment" or as "frank penetration". Age, gender, body mass index, bone mineral density, diagnosis, operation time, estimated blood loss (EBL), level of fusion, surgeon's position, spinal alignment, quality/quantity of multifidus muscle, and depth to screw entry point were considered to be demographic and anatomical variables capable of affecting pedicle screw placement. Pedicle dimensions, facet joint arthritis, screw location (ipsilateral or contralateral), screw length, screw diameter, and screw trajectory angle were regarded as screw-related variables. Logistic regression analysis was conducted to examine relations between these variables and the correctness of screw placement. The incidence of cortical encroachment was 12.5% (61 screws), and frank penetration was found for 54 (11.1%) screws. Two patients (0.4%) with medial penetration underwent revision for unbearable radicular pain and foot drop, respectively. The odds ratios of significant risk factors for pedicle screw misplacement were 3.373 (95% CI 1.095-10.391) for obesity, 1.141 (95% CI 1.024-1.271) for pedicle convergent angle, 1.013 (95% CI 1.006-1.065) for EBL >400 cc, and 1.003 (95% CI 1.000-1.006) for cross-sectional area of multifidus muscle. Although percutaneous insertion of pedicle screws was performed safely during MITLIF, several risk factors should be considered to improve placement accuracy.

Surgical correction of fixed kyphosis.

STUDY DESIGN: A retrospective review was carried out on 23 patients with rigid fixed kyphosis who underwent surgical correction for their deformity. PURPOSE: To report the results of surgical correction of fixed kyphosis according to the surgical approaches or methods. OVERVIEW OF LITERATURE: Surgical correction of fixed kyphosis is more dangerous than the correction of any other spinal deformity because of the high incidence of paraplegia. METHODS: There were 12 cases of acute angular kyphosis (6 congenital, 6 healed tuberculosis) and 11 cases of round kyphosis (10 ankylosing spondylitis, 1 Scheuermann's kyphosis). Patients were excluded if their kyphosis was due to active tuberculosis, fractures, or degenerative lumbar changes. Operative procedures consisted of anterior, posterior and combined approaches with or without total vertebrectomy. Anterior procedure only was performed in 2 cases, while posterior procedure only was performed in 8 cases. Combined procedures were used in 13 cases, including 4 total vertebrectomies. RESULTS: The average kyphotic angle was 71.8 degrees preoperatively, 31.0 degrees postoperatively, and the average final angle was 39.2 degrees . Thus, the correction rate was 57% and the correction loss rate was 12%. In acute angular kyphosis, correction rate of an anterior procedure only was 71%, correction rate of the combined procedures without total vertebrectomy was 49% and correction rate of the combined procedures with total vertebrectomy was 60%. In round kyphosis, correction rate of posterior procedure only was 65% and correction rate of combined procedures was 59%. The clinical results according to the Kirkaldy-Willis scale demonstrated 17 excellent outcomes, 5 good outcomes and one poor outcome. CONCLUSIONS: Our data indicates that the combined approach and especially the total vertebrectomy showed the safety and the greatest correction rate if acute angular kyphosis was greater than 60 degrees.