Factors affecting cigarette smoking among adolescents in South Korea, Vietnam, and Thailand.

PURPOSE: The current study was designed to describe risk and preventive factors related to cigarette smoking among adolescents in South Korea, Vietnam, and Thailand. DESIGN AND METHODS: A cross-sectional descriptive design was used. Student data were extracted from three national data sets, specifically the Global Youth Tobacco Survey from each country. Complex sampling multinomial logistic regression was performed to find factors related to current smoking. RESULTS: The prevalence of cigarette smoking was 4.7% in South Korean students, 2.8% in Vietnamese students, and 10.9% in Thai students. Students shared three risk factors related to current smoking: male sex, use of other tobacco products, and susceptibility to smoking. Additionally, only one preventive factor of cigarette smoking was found among South Korean adolescents: exposure to antitobacco advertisements. The findings suggest that personal, familial, social, and public area characteristics are associated with smoking among adolescents from these nations. PRACTICE IMPLICATIONS: These results could be useful for screening students vulnerable to cigarette smoking and the collaborative planning of interventions to prevent adolescents from smoking in these three Asian countries.

Under general anesthesia arginine vasopressin prevents hypotension but impairs cerebral oxygenation during arthroscopic shoulder surgery in the beach chair position.

BACKGROUND: Patients undergoing surgery in the beach chair position (BCP) are at a risk of cerebral ischemia. We evaluated the effect of arginine vasopressin (AVP) on hemodynamics and cerebral oxygenation during surgery in the BCP. METHODS: Thirty patients undergoing shoulder surgery in BCP under propofol-remifentanil anesthesia were randomly allocated either to receive IV AVP 0.07 U/kg (AVP group, N = 15) or an equal volume of saline (control group, N = 15) 2 minutes before taking BCP. Mean arterial blood pressure (MAP), heart rate (HR), jugular venous bulb oxygen saturation (SjvO2), and regional cerebral tissue oxygen saturation (SctO2) were measured after induction of anesthesia and before (presitting in supine position) and after patients took BCP. RESULTS: AVP itself given before the positioning increased MAP and decreased SjvO2 and SctO2 (P < 0.0001), with HR unaffected. Although MAP was decreased by BCP in both groups, it was higher in the AVP group (P < 0.0001). While in BCP, HR remained unaltered in the control and decreased in the AVP group. SjvO2 in BCP did not differ between the groups. SctO2 was decreased by BCP in both groups, which was more pronounced in the AVP group until the end of study. The incidence of hypotension (13% vs 67%; P = 0.003) was less frequent, and that of cerebral desaturation (>20% SctO2 decrease from presitting value) (80% vs 13%; P = 0.0003) was higher in the AVP group. The incidence of jugular desaturation (SjvO2 <50%) was comparable between the groups. CONCLUSIONS: A prophylactic bolus administration of AVP prevents hypotension associated with BCP in patients undergoing shoulder surgery under general anesthesia. However, it was associated with regional cerebral but not jugular venous oxygen desaturation on upright positioning.

Remifentanil decreases sevoflurane requirements to block autonomic hyperreflexia during transurethral litholapaxy in patients with high complete spinal cord injury.

BACKGROUND: An inhaled anesthetic concentration required to block autonomic hyperreflexia (AHR) is high enough to cause severe hypotension in patients with high spinal cord injury (SCI). We determined the effects of remifentanil on the sevoflurane requirement to block AHR in SCI. METHODS: The study involved 96 patients with chronic, complete SCI scheduled to undergo transurethral litholapaxy during general anesthesia. Anesthesia was induced with thiopental, and sevoflurane concentrations in 50% nitrous oxide were adjusted to maintain a bispectral index of 40 to 50. Whether the patient develops an AHR [an increase of systolic blood pressure (SBP) >20 to 40 mm Hg] was first examined by distending the bladder with glycine solution (the first trial). Patients who developed AHR were then allocated to receive no remifentanil infusion (control, n = 31), a target-controlled plasma concentration of 1 ng/mL (n = 25), or 3 ng/mL remifentanil (n = 24). After baseline hemodynamics had recovered, the target sevoflurane and remifentanil concentrations were maintained for at least 20 minutes and the procedure was resumed (the second trial). Each target sevoflurane concentration was determined by the up-and-down method based on changes (15% increase or more) of SBP in response to the bladder distension. SBP, heart rate, and bispectral index were measured before and during the bladder distension during the trials, and plasma concentrations of catecholamines during the first trial. RESULTS: Eighty-two (85.4%) of 96 patients developed AHR during the first trial, in which 2 were excluded because of hypotension (mean arterial blood pressure <50 mm Hg) developed during target-controlled drug administration. During the second trial, the end-tidal concentrations of sevoflurane to prevent AHR were reduced to 2.6% (95% confidence interval 2.5% to 2.8%, P < 0.01) and 2.2% (2.1% to 2.4%, P < 0.0001) in the groups receiving 1 and 3 ng/mL remifentanil, respectively, in comparison with 3.1% (2.9% to 3.3%) in the control. When considering minimum anesthetic concentration (MAC) values and the contribution of 50% nitrous oxide (0.48 MAC), the combined MAC values, expressed as multiples of MAC, were 2.27, 1.98, and 1.75 in the control, 1 ng/mL remifentanil, and 3 ng/mL remifentanil groups, respectively. CONCLUSIONS: Target-controlled concentrations of 1 and 3 ng/mL remifentanil would reduce the requirement of sevoflurane combined with 50% nitrous oxide to block AHR by 16% and 29%, respectively, in SCI patients undergoing transurethral litholapaxy.

Polymyxin B, scavenger of endotoxin, enhances isolation yield and in vivo function of islets.

Collagenase purified from bacteria has been used to isolate islets for transplantation. However, collagenase is contaminated with small amounts of endotoxin, which induces dysfunction or apoptosis of islets. In this study, we investigated the effects of polymyxin B, endotoxin scavenger, on the yield and quality of isolated islets. It is revealed that polymyxin B neutralized endotoxin in vitro and inhibited endotoxin-mediated decreases of the glucose stimulation index. Additionally, adenosine triphosphate (ATP) quantitation, islet regression assay, and caspase-3 activation assay demonstrated that polymyxin B efficiently blocked the toxic effects induced by endotoxin. Thereafter, we isolated mouse islets both with and without polymyxin B and compared total islet equivalents (IEQs), glucose-stimulated insulin release, and ATP content. Polymyxin B enhanced islet recovery, and ATP content of islets, and glucose stimulation index, and reduced TNF-alpha expression of islets. Marginal transplantation (200 IEQs/mouse) under the kidney capsule of diabetic mice induced normoglycemia in 30% of the polymyxin B group, but not in any mouse of control group. This result suggests that islets isolated with polymyxin B more effectively lower blood glucose levels as compared with control islets. Thus, polymyxin B could serve as a useful agent in the protection of islets from endotoxin-induced inflammation and apoptosis.