Perioperative antibiotic administration in orthopaedic trauma: a quality assurance project.

Perioperative antibiotic prophylaxis has been a mainstay of orthopaedic trauma care for decades. Despite ongoing controversy regarding the optimal number of doses required, established guidelines for use have been in place for years. A retrospective quality assurance project was conducted in Calgary, Alberta, Canada, to review local practice regarding perioperative antibiotic administration in orthopaedic trauma and compare that to what is suggested in the literature.

Intraperitoneal gas insufflation will be required for laparoscopic visualization in space: a comparison of laparoscopic techniques in weightlessness.

BACKGROUND: Laparoscopic surgery (LS) is contemplated during long duration space flight, but it typically necessitates intraabdominal hypertension (IAH) from insufflation to create a surgical domain. Because there are spontaneous changes in abdominal wall behavior in weightlessness (0g) that have been previously suggested to increase LS visualization, we studied the comparative laparoscopic visualization between gasless (noGAS), abdominal wall retraction (AWR), and standard 15 mmHg gas insufflation (GAS) during weightlessness. STUDY DESIGN: In-flight LS was performed on four anesthetized pigs during weightlessness obtained through parabolic flight in a research aircraft. GAS was studied during 27 parabolas and compared with 20 parabolas using AWR-LS and 12 with noGAS. Pelvic visualization was scored in real time during flight by 2 or 3 surgeons per parabola and postflight through review of compiled digital video disk (DVD) images by 29 independent reviewers. Physical measurements of the sagittal (anterior-posterior) and transverse dimensions of anesthetized pigs were recorded during 39 parabolas. RESULTS: Despite consistent increases in the sagittal abdominal dimension in weightlessness (GAS and noGAS), on-board scored visualization in 0g was unchanged for noGAS (p=0.78) and decreased during AWR (p=0.09), compared with 1g. Although AWR was considered feasible in 1g, spontaneous visceral movements reduced the surgical domain in 0g. Neither AWR nor noGAS was believed safe. But visualization during GAS in 0g was increased over that in 1g (p < 0.001). CONCLUSIONS: Both noGAS and AWR are impractical in weightlessness. Gas insufflation will be required. With insufflation, visualization and perceived ability to perform LS was improved by weightlessness.

The OPTICC trial: a multi-institutional study of occult pneumothoraces in critical care.

BACKGROUND: The management of pneumothoraces detected on CT but not on supine chest radiographs remains controversial, especially in those undergoing positive pressure ventilation (PPV) who are at risk for complications with both observation and treatment. Previous limited study yielded confusion regarding the need for routine drainage of these occult pneumothoraces (OPTXs). We conducted a pilot study at 2 trauma centers to address the feasibility and safety of randomizing traumatized patients undergoing PPV to drainage or observation. METHODS: Stable mechanically ventilated (or en route to surgery) adults with OPTXs were identified at 2 centers (Calgary and Quebec). Patients were randomized to observation (unless drainage became clinically indicated) or to chest drainage. Episodes of respiratory distress (need for thoracostomy tube, acute/sustained increase in oxygen requirements, difficulty in achieving adequate ventilation and self-reported distress) and subsequent imaging abnormalities were recorded until discharge. RESULTS: From August 2006 to April 2008, 24 trauma patients were enrolled (17 Calgary and 7 Quebec), with 2 later exclusions (final CT found no OPTX). Thirteen patients (59%) were randomized to observation, 9 to drainage (41%). Four observed (31%) later had chest tubes placed nonurgently for worsening OPTXs/effusions; none with increased morbidity. Overall rates of respiratory distress (drainage: 33%, observation: 41%) and mortality (drainage: 22%, observation: 15%) were similar across groups, as were median intensive care unit (drainage: 3, observation: 4) and in-hospital days (drainage: 10, observation: 16). CONCLUSIONS: With no important differences in morbidity, the OPTICC pilot lays the foundation for a future definitive trial comparing drainage or observation in posttraumatic OPTXs requiring PPV.

Intra-abdominal pressure effects on porcine thoracic compliance in weightlessness: implications for physiologic tolerance of laparoscopic surgery in space.

OBJECTIVE: Laparoscopic surgery (LS) is envisioned as an option for spaceflight, but requires intra-abdominal hypertension (IAH) to create the surgical domain. Prolonged weightlessness induces physiologic deconditioning that questions the ability of ill or injured astronauts to tolerate IAH. On earth, IAH results in marked ventilatory embarrassment. As there has been no previous study of physiologic changes related to LS in weightlessness, we studied anesthetized pigs in parabolic flight. DESIGN: Parabolic flight research laboratory. SUBJECTS: Five anesthetized Yorkshire pigs. INTERVENTIONS: Subjects were transported from an animal care facility and secured aboard an aircraft capable of generating hypergravity and weightlessness. Mechanical ventilation was performed using pressure control and positive end-expiratory pressure at 15 and 2 cm H2O, respectively; rate 12 breaths/min. Three abdominal conditions were used during LS: insufflation to produce IAH, abdominal wall retraction (AWR), and no abdominal wall manipulation (baseline). During each parabola breath by breath-tidal volumes (Vt) were recorded by a transport ventilator (HT-50 Newport Medical). MEASUREMENTS AND MAIN RESULTS: Least square means (LS-means) of weight corrected Vt (milliliter per kilogram) by gravity (g) and abdominal condition were determined using a mixed effects model for repeated measures analysis. Increasing gravity (g) consistently reduced Vt (p = 0.0011) as did insufflation (p < 0.0001). In 1g, Vt (LS-mean 13.7, 95% confidence interval [CI]: 12.4-15.0) was relatively unaffected by AWR (LS-mean 12.8, 95% CI: 11.5-14.00), but markedly decreased by IAH (LS-mean 10.00, 95% CI: 8.9-11.1), an effect accentuated in hypergravity (LS-mean 8.1, 95% CI: 6.4-9.8). In weightlessness, Vt reduction during insufflation was near obviated (LS-mean 12.3, 95% CI: 10.6-14.1), and AWR regularly but inconsistently increased the Vt above 1g baseline (LS-mean 13.7, 95% CI: 11.7-15.8). CONCLUSIONS: Weightlessness protects against thoracic compliance changes that are inherent in IAH during induced pneumoperitoneum in gravity. The technique-related physiologic cost of performing LS in space deconditioned astronauts should be incorporated into design concepts for space surgery systems.

Intraoperative frozen-section analysis for thyroid nodules: a step toward clarity or confusion?

OBJECTIVES: To determine accuracy and intertest agreement of preoperative fine-needle aspiration cytology (FNAC) and intraoperative frozen-section analysis (FS) findings in thyroid surgery, and to assess the influence of intraoperative FS findings on decision making and the utility of FS in thyroid surgery. DESIGN: Retrospective analysis. The results of preoperative FNAC, intraoperative FS, and final histopathological analyses were taken from the histopathology reports. We calculated intertest agreement using the kappa statistic. PATIENTS: Two-hundred fifteen patients who underwent primary thyroid surgery. All patients were treated by the same surgeon (S.J.W.). RESULTS: T he sensitivity and specificity of FNAC were 57.4% and 91.7%, respectively. The sensitivity and specificity of FS were 32.4% and 96.5%, respectively. The intertest agreement was poor (kappa = 0.17). In case of malignant FNAC findings, the FS result did not influence treatment decisions; in case of a malignant FS result on the background of a benign, indeterminate, or nondiagnostic FNAC finding, the FS result influenced treatment decisions in 88% of cases. CONCLUSIONS: Intraoperative FS did not give additional information in cases where a malignant neoplasm was predicted by the FNAC finding. In this setting, it led to conflicting results and did not contribute to correct decision making.

Endometrial cancer survival among U.S. black and white women by birth cohort.

BACKGROUND: Endometrial cancer incidence is lower but mortality is higher among black relative to white women. This disparity results from a relatively higher level of case-fatality in African Americans. We investigated whether the inter-racial difference in survival has diminished in more recent birth cohorts. METHODS: Women diagnosed with endometrial malignancies during 1977-1996 were identified from the U.S. Surveillance, Epidemiology and End Results program (45,261 white and 1986 black women). We calculated cumulative 5-year relative survival for 6 birth cohorts. RESULTS: Survival was relatively higher in younger women than older women and in women diagnosed in earlier years compared with more recent years. Higher survival was evident in more recent birth cohorts for groups of women 60+ years of age and in all time periods, particularly for black women. CONCLUSIONS: Although black women with endometrial cancer have a poorer prognosis than white women, the inter-racial difference in survival has narrowed in more recent birth cohorts.

Urban-rural differences in motor vehicle crash fatality and hospitalization rates among children and youth.

This population-based study examined motor vehicle crash hospitalization rates and death rates among children and youth in rural and urban areas of the province of Alberta, Canada. Using police report data (1997-2002, inclusive), average annual motor vehicle crash hospitalization and death rates among those 0-19 years of age were calculated for rural and urban regions. Across all age and sex strata examined, both the hospitalization and the fatality rates were significantly higher in rural compared with urban regions. After adjusting for age, sex and calendar year, the relative risk of a motor vehicle crash hospitalization (rural versus urban) was 3.0 (95% CI: 2.8, 3.2). After adjusting for age, sex and calendar year, the relative risk of a motor vehicle crash fatality was 5.4 (95% CI: 4.2, 6.9). Motor vehicle crash injury hospitalization and fatality rates among children and youth in the province of Alberta are considerably higher in rural areas compared with urban areas. There is a need to identify social, demographic and environmental driving hazards associated with the rural environment.

Risk assessment for inherited susceptibility to cancer: a review of the psychosocial and ethical dimensions.

The objective of this study was to conduct a broad-based systematic review of social, ethical, and legal considerations associated with genetic cancer risk assessment technologies (CaRATs). This paper focuses on psychosocial and ethical issues. Search results were limited to papers published in English, French, or German from January, 1990, to May, 2003. A quality assessment tool was developed and applied to retrieved papers. Application of the quality assessment tool resulted in 77 of 247 qualitative and quantitative primary research papers being reviewed and synthesized. A broad range of issues were addressed and grouped into content areas. Despite a large literature addressing psychosocial and ethical issues associated with CaRATs, many existing studies are not adequate to inform decision-makers and stakeholders. Careful policy analysis, as in some of the economic analyses reviewed here, is important to bridge this gap.

Influence of socioeconomic status on the effectiveness of bicycle helmet legislation for children: a prospective observational study.

OBJECTIVE: To evaluate the influence of average family income in a geographic area on the effectiveness of helmet legislation on observed helmet use by children (5-14 years). METHODS: The study was conducted in East York, a health district of Metropolitan Toronto, in collaboration with the East York Health Unit. In 1996, the total population was 107 822, 11 340 of which were children 5 to 14 years. Census data were used to group the 21 census tracts in East York into 7 geographically distinct areas. The boundaries of these areas are natural barriers to travel, such as expressways, ravines, railway tracks, and hydroelectric power lines. The areas were also ranked according to average family income (based on Statistics Canada data). For analytical purposes, areas were defined as low-, mid-, and high-income areas. Census data profiles of the areas have been previously described. For each consecutive year from 1990 to 1997 inclusive, direct observations of children riding bicycles in East York during the months of April through October were made. In 1995, observations were completed before the introduction of the law on October 1, 1995. Only children who were between 5 and 14 years of age and riding a 2-wheeled bicycle were included in the study. In total, 111 sites across all 7 areas were selected for observation. Observational sites included school yards of all elementary and middle schools (kindergarten to grade 8) and all parks in East York. In addition, 5 major intersections and 5 residential streets from each area were randomly selected. Observers were trained and used a standardized data collection form. A pilot study showed that the data collected by observers were reliable and valid. Observers remained at each site for 1 hour and collected data on helmet use and sex. Ethical approval for the study was obtained from the Hospital for Sick Children Research Ethics Board, the East York Board of Education, and the Metropolitan Separate School Board. The proportion of children who were wearing a bicycle helmet was estimated by year (1990-1997, inclusive), sex (male, female), location (school, park, major intersection, residential street), and income area (low, mid, high). For estimating the effect of legislation on helmet use, data from the year immediately after legislation (1996) were compared with data from the year preceding legislation (1995). The relative risk (RR) of helmet use (after vs before legislation) was calculated along with a 95% confidence interval (CI). Logistic regression analysis was used to adjust for potential confounding variables (sex and location). RESULTS: During the 8-year study period, 9768 observations were made (range: 914-1879 observations per year). The proportion of child cyclists who wore a bicycle helmet increased steadily during the first 4 years of the study period, from 4% in 1990 (34 of 914), to 16% in 1991 (303 of 1879), to 25% in 1992 (383 of 1563), and to 45% in 1993 (438 of 984). During 1994 (460 of 1083) and 1995 (568 of 1227), helmet use remained relatively stable at approximately 44%. Helmet use rose markedly in 1996 (the first year after helmet legislation was introduced) to 68% (818 of 1202) and remained stable at 66% (609 of 916) in 1997. Throughout the study period, girls were consistently more likely to wear helmets than were boys. In total, 47% (1420 of 3047) of girls wore helmets, compared with 33% (2193 of 6721) of boys (RR: 1.43; 95% CI: 1.36-1.50). In addition, children who were riding to school were more likely to use helmets, compared with children who were riding on residential streets, major intersections, and parks. Overall, 48% (1497 of 3129) of children who were riding to school wore bicycle helmets, compared with 32% (2116 of 6639) of children who were riding at other locations (RR: 1.50; 95% CI: 1.43-1.58). Children in the high-income areas were consistently more likely to wear helmets, compared with children in the mid- and low-income areas. Helmet legislation was associated with a significant increase in helmet use by children in East York. In 1995, 46% (ast York. In 1995, 46% (568 of 1227) of children wore bicycle helmets, compared with 68% (818 of 1202) of children in 1996 (RR: 1.47; 95% CI: 1.37-1.58). The effect of legislation, however, varied by income area. In low-income areas, helmet use increased by 28% after legislation, from 33% (213 of 646) in 1995 to 61% (442 of 721) in 1996 (RR: 1.86; 95% CI: 1.64-2.11). In mid-income areas, helmet use increased by 29% after legislation, from 50% (150 of 300) in 1995 to 79% (185 of 234) in 1996 (RR: 1.58; 95% CI: 1.39-1.80). In high-income areas, helmet use increased by only 4%, from 73% (205 of 281) in 1995 to 77% (191 of 247) in 1996 (RR: 1.06; 95% CI: 0.96-1.17). This finding of a significant increase in helmet use after legislation in low- and mid-income areas but not in high-income areas remained even after logistic regression analysis adjusted for sex and location. CONCLUSIONS: This study showed that bicycle helmet use by children increased significantly after helmet legislation. In this urban area with socioeconomic diversity and in the context of prelegislation promotion and educational activities, the legislative effect was most powerful among children who resided in low-income areas.

Risk factors for colorectal cancer following breast cancer.

OBJECTIVE: To investigate risk factors for colorectal cancer following breast cancer. METHODS: In this nested case-control study, all women (n = 14,900) with a first primary breast cancer (1978-1992) were identified from the western Washington population-based Surveillance, Epidemiology, and End Results Cancer Registry. Cases (n = 160) developed a second primary colorectal cancer before 1995, at least 6 months after the first cancer diagnosis. Controls (n = 310, matched to the cases on calendar year, age and breast cancer stage) were randomly selected from those who did not develop a second primary cancer and who survived to the case's colorectal cancer diagnosis date. Characteristics of the cases and controls at initial diagnosis were compared using conditional logistic regression. RESULTS: The incidence of colorectal cancer was associated with a family history of breast cancer (v.s. no family history, matched odds ratio (mOR) = 2.1, 95% confidence interval (CI): 1.1-4.1), high body mass index (> or = 30kg/m2 v.s. < 30kg/m2, mOR = 2.2, CI: 1.2-3.9), and lobular breast cancer histology (v.s. ductal, mOR = 2.0, CI: 0.9-4.4). Risk was unrelated to menopausal status, prior hormone replacement therapy and estrogen/progesterone receptor status of the breast tumors. CONCLUSIONS: The risk of developing a second primary colorectal cancer may be elevated among certain subsets of breast cancer patients.

A review of p53 expression and mutation in human benign, low malignant potential, and invasive epithelial ovarian tumors.

BACKGROUND: In the current study, the authors present pooled data from studies that investigated p53 protein expression and/or mutation in human epithelial ovarian tumors. METHODS: The English literature in the MEDLINE, PubMed, and Ingenta databases was searched to the end of the year 2000 to identify relevant studies. Data were pooled across eligible studies, and the prevalence of p53 expression and mutation among benign, low malignant potential (LMP), and invasive tumors was determined. Prevalence estimates by tumor histology, International Federation of Gynecology and Obstetrics (FIGO) stage, and grade also were calculated. RESULTS: The pooled prevalence estimate for p53 overexpression among epithelial ovarian carcinomas was 51% (95% confidence intervals [95% CI], 50-53%) compared with 17% (95% CI, 15-20%) among LMP tumors and 7% (95% CI, 5-10%) among benign tumors. p53 mutation prevalence estimates were 45% (95% CI, 42-47%), 5% (95% CI, 2-9%), and 1% (95% CI, 0-5%), respectively, for invasive, LMP, and benign tumors. The prevalence of these p53 abnormalities was found to be associated positively with increasing tumor grade and stage. Differences based on histologic subtype also were found. CONCLUSIONS: Although these pooled estimates might appear to offer support for various hypotheses regarding the role of p53 in ovarian carcinoma, the limitations inherent in these data hamper the interpretation of the significance of any of the findings. Future studies will require innovative methods to address the limitations of many previous investigations and more comprehensive investigation into defective tumor suppression mechanisms.

A small area study of motor vehicle crash fatalities in Alberta, Canada.

This study examined the small area variation in motor vehicle crash fatality rates in the province of Alberta, Canada. Motor vehicle crash fatality rates per 100000 population (1995-1997, inclusive) were determined for five geographic areas in the province. The rates showed substantial, statistically significant variation across areas, with fatality rates lowest in the urban areas of Calgary and Edmonton, and highest in the rural areas (south, central, and northern Alberta). Examination of area-level predictors-population density, impaired driving citation rates, education level, unemployment levels, and ethnicity-showed that population density and impaired driving rates were associated with motor vehicle crash fatality rates. There was a five-fold difference in annual motor vehicle crash fatality rates between rural (22.9/100000) and urban areas (4.4/100000), whereas annual impaired driving rates were around 1.8% in rural areas, compared with 0.6% in urban areas. Because of multicollinearity problems, it was not possible to estimate a multivariable Poisson regression model. In conclusion, rural areas in the province of Alberta demonstrate a significantly higher motor vehicle crash fatality rate, compared with urban areas.