Prevalence, correlates and patterns of waterpipe smoking among secondary school students in southeast London: a cross-sectional study.

BACKGROUND: Waterpipe smoking is growing worldwide, but little is known of its epidemiology in the UK due to its absence from national health surveys. We sought to address this by calculating the prevalence of waterpipe smoking among secondary school students in southeast London. METHODS: We conducted a pooled secondary analysis of routine health surveillance surveys among 11-17 year olds in convenience-sampled secondary schools from three ethnically-diverse areas of southeast London. We calculated ever (lifetime) waterpipe use, and compared its sociodemographic correlates to ever (lifetime) cigarette use. In one area we collected data on patterns of waterpipe use. RESULTS: Of 2,098 respondents (mean age 14.1 ± 1.7 years, 55.7 % male, 46.6 % of black ethnicity), ever waterpipe use was 39.6 % (95 % CI 37.6-41.7 %) and was higher than that for ever cigarette use (32.4 %; 95 % CI 30.5-34.4). While waterpipe users were significantly and independently more likely to be male and of non-white ethnicities, at least 30 % of all age, gender and ethnic sub-groups had tried waterpipe smoking. In contrast, cigarette users were more likely to be older and of white ethnicity. In one of the three areas, over a quarter of waterpipe users were occasional or regular waterpipe smokers, and most were introduced to and currently used waterpipe in waterpipe-serving premises or friends' homes. CONCLUSIONS: Waterpipe smoking prevalence was high in southeast London, and users exhibited a different sociodemographic profile to cigarette users. Waterpipe should be included in national health surveys of young people. National surveillance is warranted to help develop suitable interventions to prevent uptake and promote cessation.

Waterpipe tobacco and electronic cigarette use in a southeast London adult sample: a cross-sectional analysis.

BACKGROUND: Waterpipe tobacco and electronic cigarettes (e-cigarettes) share several features: rising popularity, use of product flavourings and concerns about marketing to youth. We sought to compare prevalence and predictors of waterpipe tobacco and e-cigarette use, and explore knowledge of waterpipe tobacco and support for interventions. METHODS: We used convenience sampling methods to conduct a cross-sectional survey among adults in the ethnically diverse southeast London area. Multivariate logistic regression identified predictors of waterpipe and e-cigarette use. Predictor variables were age, gender, ethnicity and current (past 30-day) cigarette use. RESULTS: Of 1176 respondents (23.0% aged 25-34 years, 56.0% male, 57.4% white ethnicity and 30.4% current cigarette smokers), 31.0% had tried waterpipe tobacco and 7.4% had tried e-cigarettes. Both products were significantly associated with younger age groups, non-white ethnicities and use of each other. Waterpipe tobacco was independently associated with consumption of cigarettes while e-cigarettes were not. Among those aware of waterpipe, a third answered incorrectly to knowledge questions. Among those self-identified as coming from a traditional waterpipe-using community, two-thirds supported further legislative and health promotion waterpipe interventions. CONCLUSIONS: Waterpipe tobacco was common and more prevalent than e-cigarettes in this population. Interventions to prevent and control waterpipe are unlikely to marginalize traditional waterpipe-using communities.

Sodium reduction during cardiopulmonary bypass: Plasma-Lyte 148 versus trial fluid as pump primes.

OBJECTIVES: We compared effects on plasma sodium concentrations plus calculated plasma tonicity of two "balanced" crystalloid solutions used as 2 L pump primes during cardiopulmonary bypass (CPB): Plasma-Lyte 148 (sodium concentration, 140 mmol/L; potassium concentration, 5 mmol/L) versus a bicarbonate-balanced fluid (sodium concentration, 140 mmol/L; potassium concentration, 0 mmol/L). DESIGN, SETTING AND PARTICIPANTS: We analysed pooled data from two prospective interventional studies performed in university-affiliated hospitals, from 50 patients undergoing elective cardiac surgery. INTERVENTIONS: Participants were allocated equally to Plasma-Lyte 148 or bicarbonate-balanced fluid, with plasma electrolytes measured by direct ion selective electrodes immediately before bypass (pre-CPB), within 3 minutes of commencement (T2), and before bypass cessation (end-CPB). RESULTS: Plasma sodium fell at T2 in 46 patients (92%) (P<0.0005). With Plasma-Lyte 148, the mean sodium decreased by 3.0 mmol/L (SD, 1.7 mmol/L), and with bicarbonate-balanced fluid it decreased by 2.2 mmol/L (SD, 1.1 mmol/L) (P=0.002). The mean tonicity fell by >5 mOsm/kg for both groups (P<0.0005). At end-CPB, the mean sodium for both groups remained reduced by >2 mmol/L (P<0.0005). In the group receiving Plasma-Lyte 148, 52% of patients were hyponatraemic (sodium<135 mmol/L) at T2 and end-CPB. CONCLUSIONS: Sodium reductions were common with both priming solutions, but more severe with Plasma-Lyte 148. Crystalloid priming solutions require sodium concentrations>140mmol/L to ensure normonatraemia throughout CPB.

Preliminary analysis of perfusionists' strategies for managing routine and failure mode scenarios in cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) is a complex task requiring high levels of practitioner expertise. Although some education standards exist, few are based on an analysis of perfusionists' problem-solving needs. This study shows the efficacy of work domain analysis (WDA) as a framework for analyzing perfusionists' conceptualization and problem-solving strategies. A WDA model of a CPB circuit was developed. A high-fidelity CPB simulator (Manbit) was used to present routine and oxygenator failure scenarios to six proficient perfusionists. The video-cued recall technique was used to elicit perfusionists' conceptualization strategies. The resulting recall transcripts were coded using the WDA model and analyzed for associations between task completion times and patterns of conceptualization. The WDA model developed was successful in being able to account for and describe the thought process followed by each participant. It was also shown that, although there was no correlation between experience with CPB and ability to change an oxygenator, there was a link between the between specific thought patterns and the efficiency in undertaking this task. Simulators are widely used in many fields of human endeavor, and in this research, the attempt was made to use WDA to gain insights into the complexities of the human thought process when engaged in the complex task of conducting CPB. The assumption that experience equates with ability is challenged, and rather, it is shown that thought process is a more significant determinant of success when engaged in complex tasks. WDA analysis in combination with a CPB simulator may be used to elucidate successful strategies for completing complex tasks.