Measuring air quality to protect children from secondhand smoke in cars

BACKGROUND: Secondhand tobacco smoke (SHS) is a major, preventable contributor to acute and chronic adverse health outcomes that affect children disproportionately. The predominant source of SHS among children is domestic exposure, and while up to two thirds of U.S. households have car smoking bans, an unacceptable number of children remain vulnerable. To help promote more effective protection through legislation, health communication strategies, or behavioral interventions, data demonstrating the adverse effect of SHS on air quality in cars are needed. METHODS: Secondhand tobacco smoke in a motor vehicle under actual driving conditions was monitored by measuring respirable suspended particles (RSPs) of less than 2.5 microns in diameter, and carbon monoxide. Forty-five driving trials were conducted, using teams of volunteer drivers and smokers recruited from the general community. Three smoking conditions (nonsmoking baseline, active smoking, and immediate post-smoking period, each 5 minutes) were crossed with two ventilation conditions (windows open, closed) in a 3 x 2 within-sessions factorial design. RESULTS: The highest mean observed RSP level was 271 mug/m(3), which is unsafe, particularly for children. Peak RSP levels were considerably higher. RSPs and carbon monoxide increased significantly from baseline after smoking, and these increases were greatest during the closed ventilation condition, compared with open ventilation. CONCLUSIONS: Private passenger cars are a domestic environment with the potential to yield unsafe levels of SHS contaminants. These data may assist policymakers and health advocates to promote protective strategies to ensure smoke-free domestic environments for children.     

Surgical resection of hepatic metastases from colorectal cancer: a systematic review of published studies

No consensus on the indications for surgical resection of colorectal liver metastases exists. This systematic review has been undertaken to assess the published evidence for its efficacy and safety and to identify prognostic factors. Studies were identified by computerised and hand searches of the literature, scanning references and contacting investigators. The outcome measures were overall survival, disease-free survival, postoperative morbidity and mortality, quality of life and cost effectiveness, and a qualitative summary of the trends across all studies was produced. Only 30 of 529 independent studies met all the eligibility criteria for the review, and data on 30-day mortality and morbidity only were included from a further nine studies. The best available evidence came from prospective case series, but only two studies reported outcomes for all patients undergoing surgery. The remainder reported outcomes for selected groups of patients: those undergoing hepatic resection or those undergoing curative resection. Postoperative mortality rates were generally low (median 2.8%). The majority of studies described only serious postoperative morbidity, the most common being bile leak and associated perihepatic abscess. Approximately 30% of patients remained alive 5 years after resection and around two-thirds of these are disease free. The quality of the majority of published papers was poor and ascertaining the benefits of surgical resection of colorectal hepatic metastases is difficult in the absence of randomised trials. However, it is clear that there is group of patients with liver metastases who may become long-term disease-free survivors following hepatic resection. Such survival is rare in apparently comparable patients who do not have surgical treatment. Further work is needed to more accurately define this group of patients and to determine whether the addition of adjuvant treatments results in improved survival.     

Oxygenation within the first 120 h following coronary artery bypass grafting. Influence of systemic hypothermia (32 degrees C) or normothermia (36 degrees C) during the cardiopulmonary bypass: a randomized clinical trial

BACKGROUND: Lung function is often impaired after cardiac surgery performed under cardiopulmonary bypass (CPB). Normothermic CPB has become more common, but it remains unknown whether it reduces post-operative lung function compared with hypothermic CPB. The aim of this study was to investigate oxygenation within the first 120 h after systemic hypothermia and normothermia under CPB. METHODS: Thirty patients undergoing coronary artery bypass grafting (CABG) were randomized to either hypothermic (32 degrees C) or normothermic (36 degrees C) CPB. Oxygenation was studied by a simple method for the estimation of intrapulmonary shunt and ventilation-perfusion (V/Q) mismatch pre-operatively and 4, 48 and 120 h post-operatively by changing Fio2 in four to six steps. V/Q mismatch was described with DeltaPo2 (normal values, 0-2.38 kPa). RESULTS: Shunt and V/Q mismatch (DeltaPo2) increased post-operatively in both groups (P<0.01), with no differences between the groups, and with the nadir values 48 h after surgery, i.e. shunt of 15% (5.8-25%) and DeltaPo2 of 3.0 kPa (0.8-14 kPa) [values given as median (range)]. CONCLUSIONS: Impaired oxygenation is prevalent and prolonged following CABG, with equal intensity after hypothermic and normothermic CPB.