Extravascular lung water levels are associated with mortality: a systematic review and meta-analysis.

BACKGROUND: The prognostic value of extravascular lung water (EVLW) measured by transpulmonary thermodilution (TPTD) in critically ill patients is debated. We performed a systematic review and meta-analysis of studies assessing the effects of TPTD-estimated EVLW on mortality in critically ill patients. METHODS: Cohort studies published in English from Embase, MEDLINE, and the Cochrane Database of Systematic Reviews from 1960 to 1 June 2021 were systematically searched. From eligible studies, the values of the odds ratio (OR) of EVLW as a risk factor for mortality, and the value of EVLW in survivors and non-survivors were extracted. Pooled OR were calculated from available studies. Mean differences and standard deviation of the EVLW between survivors and non-survivors were calculated. A random effects model was computed on the weighted mean differences across the two groups to estimate the pooled size effect. Subgroup analyses were performed to explore the possible sources of heterogeneity. RESULTS: Of the 18 studies included (1296 patients), OR could be extracted from 11 studies including 905 patients (464 survivors vs. 441 non-survivors), and 17 studies reported EVLW values of survivors and non-survivors, including 1246 patients (680 survivors vs. 566 non-survivors). The pooled OR of EVLW for mortality from eleven studies was 1.69 (95% confidence interval (CI) [1.22; 2.34], p < 0.0015). EVLW was significantly lower in survivors than non-survivors, with a mean difference of -4.97 mL/kg (95% CI [-6.54; -3.41], p < 0.001). The results regarding OR and mean differences were consistent in subgroup analyses. CONCLUSIONS: The value of EVLW measured by TPTD is associated with mortality in critically ill patients and is significantly higher in non-survivors than in survivors. This finding may also be interpreted as an indirect confirmation of the reliability of TPTD for estimating EVLW at the bedside. Nevertheless, our results should be considered cautiously due to the high risk of bias of many studies included in the meta-analysis and the low rating of certainty of evidence. Trial registration the study protocol was prospectively registered on PROSPERO: CRD42019126985.

Histopathological Alterations in the Livers of Chronic Hepatitis Patients Exposed to Agent Orange/Dioxin in Vietnam.

We investigated changes in some laboratory indices and the liver histology of chronic hepatitis patients who were exposed to dioxin. In 2014, we collected liver biopsy samples for histopathological examination from 33 chronic hepatitis patients living around the Da Nang Airbase, which is a dioxin-contaminated area due to the herbicide spraying in Vietnam. Dioxin exposure was measured by its levels in the blood. METAVIR classification was used to clarify the liver fibrosis stage. Laboratory tests included ten biochemical and six hematological indices that were measured in the blood. A regression linear model and binary logistic regression were used for data analysis. The observed alterations in the liver at the histological level mainly comprised hydropic degenerative hepatocytes, lymphocytes and polynuclear leukocytes surrounding the liver cells and granular and lipoic degeneration. In addition, increased TCDD levels were associated with increasing aminotransferase (AST), alanine aminotransferase, protein and total bilirubin levels and liver fibrosis stage. Similarly, increased TEQ-PCDD/Fs levels were associated with higher levels of AST and protein and liver fibrosis stage. In conclusion, dioxin exposure altered the liver histology and increased some biochemical marker indices and the liver fibrosis stage of chronic hepatitis patients living in dioxin-contaminated areas in Da Nang, Vietnam.

The role of acute hypercapnia on mortality and short-term physiology in patients mechanically ventilated for ARDS: a systematic review and meta-analysis.

PURPOSE: Hypercapnia is frequent during mechanical ventilation for acute respiratory distress syndrome (ARDS), but its effects on morbidity and mortality are still controversial. We conducted a systematic review and meta-analysis to explore clinical consequences of acute hypercapnia in adult patients ventilated for ARDS. METHODS: We searched Medline, Embase, and the Cochrane Library via the OVID platform for studies published from 1946 to 2021. "Permissive hypercapnia" defined hypercapnia in studies where the group with hypercapnia was ventilated with a protective ventilation (PV) strategy (lower VT targeting 6 ml/kg predicted body weight) while the group without hypercapnia was managed with a non-protective ventilation (NPV); "imposed hypercapnia" defined hypercapnia in studies where hypercapnic and non-hypercapnic patients were managed with a similar ventilation strategy. RESULTS: Twenty-nine studies (10,101 patients) were included. Permissive hypercapnia, imposed hypercapnia under PV, and imposed hypercapnia under NPV were reported in 8, 21 and 1 study, respectively. Studies testing permissive hypercapnia reported lower mortality in hypercapnic patients receiving PV as compared to non-hypercapnic patients receiving NPV: OR = 0.26, 95% CI [0.07-0.89]. By contrast, studies reporting imposed hypercapnia under PV reported increased mortality in hypercapnic patients receiving PV as compared to non-hypercapnic patients also receiving PV: OR = 1.54, 95% CI [1.15-2.07]. There was a significant interaction between the mechanism of hypercapnia and the effect on mortality. CONCLUSIONS: Clinical effects of hypercapnia are conflicting depending on its mechanism. Permissive hypercapnia was associated with improved mortality contrary to imposed hypercapnia under PV, suggesting a major role of PV strategy on the outcome.

Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies.

BACKGROUND: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. METHODS: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. FINDINGS: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42·4% vs 44·2%; absolute difference -1·69 [-9·58 to 6·11] p=0·67; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5-8] vs 6 [5-8] cm H2O; p=0·0011). ICU mortality was higher in MICs than in HICs (30·5% vs 19·9%; p=0·0004; adjusted effect 16·41% [95% CI 9·52-23·52]; p<0·0001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0·80 [95% CI 0·75-0·86]; p<0·0001). INTERPRETATION: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status. FUNDING: No funding.

Frailty and Adverse Outcomes Among Older Patients Undergoing Gastroenterological Surgery in Vietnam.

PURPOSE: With the ageing population, more older adults undergo surgery, and frailty increases the risk of postoperative complications in older patients. This study aimed to determine the association between frailty and 30-day adverse outcomes in older patients undergoing gastroenterological surgery in Vietnam. PATIENTS AND METHODS: A prospective cohort study was conducted in the Gastroenterology Department of the University Medical Center in Ho Chi Minh City. Frailty was determined using Fried's criteria. Adverse outcomes within 30 days of gastroenterological surgery were recorded, including postoperative infections, acute respiratory failure, acute kidney injury, and death. Univariate and multivariate logistic analyses were performed to determine the association between frailty and 30-day postoperative adverse outcomes using Stata 14.0. RESULTS: Data of 302 elective surgical participants were collected (mean age: 69.8± 8.1 years, 53.3% female), and the prevalence of frailty was 18.5%. Frailty was an independent risk factor for 30-day adverse outcomes (odds ratio=6.56, 95% confidence interval, 2.77-15.53, p<0.001), which included postoperative infections, acute respiratory failure, acute kidney injury, and death. Frail participants had a significantly higher risk of postoperative infections (odds ratio=8.21, 95% confidence interval, 3.28-20.54, p<0.001), and exhaustion was strongly associated with postoperative adverse outcomes. CONCLUSION: Frailty was a predictor of 30-day adverse outcomes in older patients undergoing gastroenterological surgery. Therefore, preoperative frailty should be screened in older patients, and frailty-associated risks should be considered during the decision-making process by physicians, patients, and their families.

Emerging pharmacological therapies for ARDS: COVID-19 and beyond.

ARDS, first described in 1967, is the commonest form of acute severe hypoxemic respiratory failure. Despite considerable advances in our knowledge regarding the pathophysiology of ARDS, insights into the biologic mechanisms of lung injury and repair, and advances in supportive care, particularly ventilatory management, there remains no effective pharmacological therapy for this syndrome. Hospital mortality at 40% remains unacceptably high underlining the need to continue to develop and test therapies for this devastating clinical condition. The purpose of the review is to critically appraise the current status of promising emerging pharmacological therapies for patients with ARDS and potential impact of these and other emerging therapies for COVID-19-induced ARDS. We focus on drugs that: (1) modulate the immune response, both via pleiotropic mechanisms and via specific pathway blockade effects, (2) modify epithelial and channel function, (3) target endothelial and vascular dysfunction, (4) have anticoagulant effects, and (5) enhance ARDS resolution. We also critically assess drugs that demonstrate potential in emerging reports from clinical studies in patients with COVID-19-induced ARDS. Several therapies show promise in earlier and later phase clinical testing, while a growing pipeline of therapies is in preclinical testing. The history of unsuccessful clinical trials of promising therapies underlines the challenges to successful translation. Given this, attention has been focused on the potential to identify biologically homogenous subtypes within ARDS, to enable us to target more specific therapies 'precision medicines.' It is hoped that the substantial number of studies globally investigating potential therapies for COVID-19 will lead to the rapid identification of effective therapies to reduce the mortality and morbidity of this devastating form of ARDS.

Smoking habits and progression of coronary and aortic artery calcification: A 5-year follow-up of community-dwelling Japanese men.

BACKGROUND AND AIMS: To examine whether smoking habits, including smoking amount and cessation duration at baseline, are associated with atherosclerosis progression. METHODS: At baseline (2006-08, Japan), we obtained smoking status, amount of smoking and time since cessation for quitters in a community-based random sample of Japanese men initially aged 40-79 years and free of cardiovascular disease. Coronary artery calcification (CAC) and aortic artery calcification (AAC) as biomarker of atherosclerosis was quantified using Agatston's method at baseline and after 5 years of follow-up. We defined progression of CAC and AAC (yes/no) using modified criteria by Berry. RESULTS: A total of 781 participants was analyzed. Multivariable adjusted odds ratios (ORs) of CAC and AAC progression for current smokers were 1.73 (95% CI, 1.09-2.73) and 2.47 (1.38-4.44), respectively, as compared to never smokers. In dose-response analyses, we observed a graded positive relationship of smoking amount and CAC progression in current smokers (multivariable adjusted ORs: 1.23, 1.72, and 2.42 from the lowest to the highest tertile of pack-years). Among the former smokers, earlier quitters (≥10.7 years) had similar ORs of the progression of CAC and AAC to that of participants who had never smoked. CONCLUSIONS: Compared with never smokers, current smokers especially those with greater pack-years at baseline had higher risk of atherosclerosis progression in community-dwelling Japanese men. Importantly, the residual adverse effect appears to be present for at least ten years after smoking cessation. The findings highlight the importance of early avoidance or minimizing smoking exposure for the prevention of atherosclerotic disease.

Feasibility and safety of extracorporeal CO2 removal to enhance protective ventilation in acute respiratory distress syndrome: the SUPERNOVA study.

PURPOSE: We assessed feasibility and safety of extracorporeal carbon dioxide removal (ECCO2R) to facilitate ultra-protective ventilation (VT 4 mL/kg and PPLAT ≤ 25 cmH2O) in patients with moderate acute respiratory distress syndrome (ARDS). METHODS: Prospective multicenter international phase 2 study. Primary endpoint was the proportion of patients achieving ultra-protective ventilation with PaCO2 not increasing more than 20% from baseline, and arterial pH > 7.30. Severe adverse events (SAE) and ECCO2R-related adverse events (ECCO2R-AE) were reported to an independent data and safety monitoring board. We used lower CO2 extraction and higher CO2 extraction devices (membrane lung cross-sectional area 0.59 vs. 1.30 m2; flow 300-500 mL/min vs. 800-1000 mL/min, respectively). RESULTS: Ninety-five patients were enrolled. The proportion of patients who achieved ultra-protective settings by 8 h and 24 h was 78% (74 out of 95 patients; 95% confidence interval 68-89%) and 82% (78 out of 95 patients; 95% confidence interval 76-88%), respectively. ECCO2R was maintained for 5 [3-8] days. Six SAEs were reported; two of them were attributed to ECCO2R (brain hemorrhage and pneumothorax). ECCO2R-AEs were reported in 39% of the patients. A total of 69 patients (73%) were alive at day 28. Fifty-nine patients (62%) were alive at hospital discharge. CONCLUSIONS: Use of ECCO2R to facilitate ultra-protective ventilation was feasible. A randomized clinical trial is required to assess the overall benefits and harms. CLINICALTRIALS.GOV: NCT02282657.

High-flow nasal oxygen versus noninvasive ventilation in adult patients with cystic fibrosis: a randomized crossover physiological study.

BACKGROUND: Noninvasive ventilation (NIV) is the first-line treatment of adult patients with exacerbations of cystic fibrosis (CF). High-flow nasal oxygen therapy (HFNT) might benefit patients with hypoxemia and can reduce physiological dead space. We hypothesized that HFNT and NIV would similarly reduce work of breathing and improving breathing pattern in CF patients. Our objective was to compare the effects of HFNT versus NIV in terms of work of breathing, assessed noninvasively by the thickening fraction of the diaphragm (TFdi, measured with ultrasound), breathing pattern, transcutaneous CO2 (PtcCO2), hemodynamics, dyspnea and comfort. METHODS: Adult CF patients who had been stabilized after requiring ventilatory support for a few days were enrolled and ventilated with HFNT and NIV for 30 min in crossover random order. RESULTS: Fifteen patients were enrolled. Compared to baseline, HFNT, but not NIV, reduced respiratory rate (by 3 breaths/min, p = 0.01) and minute ventilation (by 2 L/min, p = 0.01). Patients also took slightly larger tidal volumes with HFNT compared to NIV (p = 0.02). TFdi per breath was similar under the two techniques and did not change from baseline. MAP increased from baseline with NIV and compared to HFNT (p ≤ 0.01). Comfort was poorer with the application of both HFNT and NIV than baseline. No differences were found for heart rate, SpO2, PtcCO2 or dyspnea. CONCLUSIONS: In adult CF patients stabilized after indication for ventilatory support, HFNT and NIV have similar effects on diaphragmatic work per breath, but high-flow therapy confers additional physiological benefits by decreasing respiratory rate and minute ventilation. CLINICAL TRIAL REGISTRATION: Ethics Committee of St. Michael's Hospital (REB #14-338) and clinicaltrial.gov (NCT02262871).

Resolved versus confirmed ARDS after 24 h: insights from the LUNG SAFE study.

PURPOSE: To evaluate patients with resolved versus confirmed ARDS, identify subgroups with substantial mortality risk, and to determine the utility of day 2 ARDS reclassification. METHODS: Our primary objective, in this secondary LUNG SAFE analysis, was to compare outcome in patients with resolved versus confirmed ARDS after 24 h. Secondary objectives included identifying factors associated with ARDS persistence and mortality, and the utility of day 2 ARDS reclassification. RESULTS: Of 2377 patients fulfilling the ARDS definition on the first day of ARDS (day 1) and receiving invasive mechanical ventilation, 503 (24%) no longer fulfilled the ARDS definition the next day, 52% of whom initially had moderate or severe ARDS. Higher tidal volume on day 1 of ARDS was associated with confirmed ARDS [OR 1.07 (CI 1.01-1.13), P = 0.035]. Hospital mortality was 38% overall, ranging from 31% in resolved ARDS to 41% in confirmed ARDS, and 57% in confirmed severe ARDS at day 2. In both resolved and confirmed ARDS, age, non-respiratory SOFA score, lower PEEP and P/F ratio, higher peak pressure and respiratory rate were each associated with mortality. In confirmed ARDS, pH and the presence of immunosuppression or neoplasm were also associated with mortality. The increase in area under the receiver operating curve for ARDS reclassification on day 2 was marginal. CONCLUSIONS: ARDS, whether resolved or confirmed at day 2, has a high mortality rate. ARDS reclassification at day 2 has limited predictive value for mortality. The substantial mortality risk in severe confirmed ARDS suggests that complex interventions might best be tested in this population. TRIAL REGISTRATION: ClinicalTrials.gov NCT02010073.

Awareness of Individual Cardiovascular Risk Factors and Self-Perception of Cardiovascular Risk in Women.

BACKGROUND: Cardiovascular risk factors (CVRFs) self-perception by women may be inaccurate. MATERIALS AND METHODS: A questionnaire was completed anonymously Online by women who self-reported their personal CVRF levels including age, weight, contraceptive use, menopausal status, smoking, diet and physical activities. Self-perceived risk was matched to actual cardiovascular risk according to the Framingham score. RESULTS: Among 5,240 young and middle-aged women with a high educational level, knowledge of personal CVRFs increased with age, from 51-90% for blood pressure (BP), 22-45% for blood glucose and 15-47% for blood cholesterol levels, between 30 and 65 years, respectively. This knowledge was lower for smoking compared with nonsmoking women: 62.5% vs. 74.5% for BP (P < 0.001), 22.7% vs. 33.8% for blood glucose (P < 0.001), 21.9% vs. 32.0% for cholesterol levels (P < 0.001). Knowledge of BP level was reduced among women using an estrogen-progestogen contraception (56.8% vs. 62.1%, P = 0.0031) and even more reduced among smokers (52.2%, P < 0.001). Conversely, women with leisure-time physical or sportive activity (60.5%), were less overweight or obese (22.4% vs. 34.2%, P < 0.001). They reported better knowledge of BP (72.4% vs. 68.3%, P < 0.001), blood cholesterol (31.1% vs. 26.4%, P < 0.001) and glucose levels (32.7% vs. 27.8%, P < 0.001). Self-perceived cardiovascular risk was rated low by 1,279 (20.4%), moderate by 3,710 (63.3%) and high by 893 (16.3%) women. Among 3,386 women tested using the Framingham score, 40.8% were at low, 25.2% at moderate and 33.8% at high risk. CONCLUSIONS: Knowledge of CVRFs and self-perception of individual risk are inaccurate in women. Educational interventions should be emphasized.

Etiologies, diagnostic work-up and outcomes of acute respiratory distress syndrome with no common risk factor: a prospective multicenter study.

BACKGROUND: Patients meeting the Berlin definition for the acute respiratory distress syndrome (ARDS) might lack exposure to one or more "common" risk factors and exhibit different clinical phenotype and outcomes. We aimed to compare the clinical presentation and outcome of ARDS patients with or without risk factors, the impact on hospital mortality, and to assess the diagnostic work-up performed. The current study is an ancillary analysis of an international, multicenter, prospective cohort study (the Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure, LUNG SAFE). Patients meeting ARDS criteria within 2 days of acute hypoxemic respiratory failure onset were included in the study and categorized as having risk factors or not. Outcomes were compared using propensity score matching. RESULTS: Among 2813 patients, 234 (8.3% [7.3-9.3]) had no ARDS risk factor identified. These were older, had more frequent chronic diseases and presented with less severe SOFA and non-pulmonary SOFA scores (p < 0.001). Compared to other ARDS, CT scan (32.1 vs 23.9%, p < 0.001) and open lung biopsy (2.6 vs 0.2%, p < 0.001) were slightly more frequent but left heart filling pressures assessment was not (69.4 vs 68.4%, p > 0.99). Among ARDS with no risk factor, 45 patients (19.2%) had a specific diagnosis made. As compared to others, patients having ARDS with no risk factor had a lower ICU but not hospital mortality (34.6 vs 40.0%; p = 0.12). A matched cohort analysis confirmed the lack of significant difference in mortality. CONCLUSION: Eight percent of ARDS patients have no identified risk factor, 80% of whom have no etiological diagnosis made. The outcome of ARDS with no risk factor was comparable to other ARDS but few had a comprehensive diagnostic work-up, potentially leading to missed curable diseases. Trial registration clinicaltrials.gov Identifier: NCT02010073.

Plastic bronchitis: An unusual complication of acute chest syndrome in adult.

Plastic bronchitis is used to designate endobronchial plugs of rubber-like consistency that form into bronchial trees. It has been described in several diseases like asthma, cystic fibrosis, pulmonary infection, cyanotic congenital heart disease and in few young children with homozygous sickle cell disease. We report the first sickle cell adult case of plastic bronchitis during acute chest syndrome. He developed severe acute respiratory distress syndrome. This unusual presentation related to obstruction by voluminous casts may alert physicians to focus more on the bronchi in sickle cell patients. Realization of fiberoptic bronchoscopy to diagnose endobronchial injury and preventive measures such as fluidification of sputum at the early stage of thoracic vaso-occlusive crisis are essential.

Potentially modifiable factors contributing to outcome from acute respiratory distress syndrome: the LUNG SAFE study.

PURPOSE: To improve the outcome of the acute respiratory distress syndrome (ARDS), one needs to identify potentially modifiable factors associated with mortality. METHODS: The large observational study to understand the global impact of severe acute respiratory failure (LUNG SAFE) was an international, multicenter, prospective cohort study of patients with severe respiratory failure, conducted in the winter of 2014 in a convenience sample of 459 ICUs from 50 countries across five continents. A pre-specified secondary aim was to examine the factors associated with outcome. Analyses were restricted to patients (93.1 %) fulfilling ARDS criteria on day 1-2 who received invasive mechanical ventilation. RESULTS: 2377 patients were included in the analysis. Potentially modifiable factors associated with increased hospital mortality in multivariable analyses include lower PEEP, higher peak inspiratory, plateau, and driving pressures, and increased respiratory rate. The impact of tidal volume on outcome was unclear. Having fewer ICU beds was also associated with higher hospital mortality. Non-modifiable factors associated with worsened outcome from ARDS included older age, active neoplasm, hematologic neoplasm, and chronic liver failure. Severity of illness indices including lower pH, lower PaO2/FiO2 ratio, and higher non-pulmonary SOFA score were associated with poorer outcome. Of the 578 (24.3 %) patients with a limitation of life-sustaining therapies or measures decision, 498 (86.0 %) died in hospital. Factors associated with increased likelihood of limitation of life-sustaining therapies or measures decision included older age, immunosuppression, neoplasia, lower pH and increased non-pulmonary SOFA scores. CONCLUSIONS: Higher PEEP, lower peak, plateau, and driving pressures, and lower respiratory rate are associated with improved survival from ARDS. TRIAL REGISTRATION: ClinicalTrials.gov NCT02010073.

High cortisol and cortisone levels are associated with breast milk dioxin concentrations in Vietnamese women.

OBJECTIVE: Dioxin (polychlorinated dibenzodioxins+polychlorinated dibenzofurans) is one of the most toxic chemical substances known. Although it is suspected to cause endocrine disruption, very few epidemiological studies have been carried out on its effects on human steroid hormones. The aim of this study was to elucidate the association of dioxin exposure with steroid hormone levels in the saliva and serum of Vietnamese women. STUDY DESIGN: Two areas, namely Phu Cat (hot spot) and Kim Bang (nonexposed area), were selected for the study. The study subjects consisted of 51 and 58 women respectively. Saliva, blood, and breast milk samples were collected from the subjects in both the areas. METHODS: Cortisol, cortisone, DHEA, androstenedione, estrone, and estradiol levels in serum and saliva were determined by liquid chromatography-tandem mass spectrometry; dioxin concentrations in breast milk were measured by gas chromatography-mass spectrometry. RESULTS: Dioxin concentrations in the breast milk of women from the dioxin hot spot were three to four times higher than those in the breast milk of women from the nonexposed area. Good correlations were found between the levels of six steroid hormones in saliva and those in serum respectively. Salivary and serum cortisol and cortisone levels in women from the dioxin hot spot were significantly higher than those in women from the nonexposed area (P<0.001) and those in all the subjects were positively associated with dioxin concentrations in Vietnamese women (P<0.01). CONCLUSION: These results suggest that dioxin influences steroidogenesis in humans. Saliva samples can be used for hormone analysis and are therefore excellent specimens in epidemiological studies.

Construct and face validity and task workload for laparoscopic camera navigation: virtual reality versus videotrainer systems at the SAGES Learning Center.

BACKGROUND: Laparoscopic camera navigation (LCN) training on simulators has demonstrated transferability to actual operations, but no comparative data exist. The objective of this study was to compare the construct and face validity, as well as workload, of two previously validated virtual reality (VR) and videotrainer (VT) systems. METHODS: Attendees (n = 90) of the SAGES 2005 Learning Center performed two repetitions on both VR (EndoTower) and VT (Tulane Trainer) LCN systems using 30 degrees laparoscopes and completed a questionnaire regarding demographics, simulator characteristics, and task workload. Construct validity was determined by comparing the performance scores of subjects with various levels of experience according to five parameters and face validity according to eight. The validated NASA-TLX questionnaire that rates the mental, physical, and temporal demand of a task as well as the performance, effort, and frustration of the subject was used for workload measurement. RESULTS: Construct validity was demonstrated for both simulators according to the number of basic laparoscopic cases (p = 0.005), number of advanced cases (p < 0.001), and frequency of angled scope use (p < 0.001), and only for VT according to training level (p < 0.001) and fellowship training (p = 0.008). Face validity ratings on a 1-20 scale averaged 15.4 +/- 3 for VR vs. 16 +/- 2.6 for VT (p = 0.04). Ninety-six percent of participants rated both simulators as valid educational tools. The NASA-TLX overall workload score was 69.5 +/- 24 for VR vs. 68.8 +/- 20.5 for VT (p = 0.31). CONCLUSIONS: This is the largest study to date that compares two validated LCN simulators. While subtle differences exist, both VR and VT simulators demonstrated excellent construct validity, good face validity, and acceptable workload parameters. These systems thus represent useful training devices and should be widely used to improve surgical performance.