Protective ventilation with high versus low positive end-expiratory pressure during one-lung ventilation for thoracic surgery (PROTHOR): study protocol for a randomized controlled trial

BACKGROUND

Postoperative pulmonary complications (PPC) may result in longer duration of in-hospital stay and even mortality. Both thoracic surgery and intraoperative mechanical ventilation settings add considerably to the risk of PPC. It is unclear if one-lung ventilation (OLV) for thoracic surgery with a strategy of intraoperative high positive end-expiratory pressure (PEEP) and recruitment maneuvers (RM) reduces PPC, compared to low PEEP without RM.

METHODS

PROTHOR is an international, multicenter, randomized, controlled, assessor-blinded, two-arm trial initiated by investigators of the PROtective VEntilation NETwork. In total, 2378 patients will be randomly assigned to one of two different intraoperative mechanical ventilation strategies. Investigators screen patients aged 18 years or older, scheduled for open thoracic or video-assisted thoracoscopic surgery under general anesthesia requiring OLV, with a maximal body mass index of 35 kg/m2, and a planned duration of surgery of more than 60 min. Further, the expected duration of OLV shall be longer than two-lung ventilation, and lung separation is planned with a double lumen tube. Patients will be randomly assigned to PEEP of 10 cmH2O with lung RM, or PEEP of 5 cmH2O without RM. During two-lung ventilation tidal volume is set at 7 mL/kg predicted body weight and, during OLV, it will be decreased to 5 mL/kg. The occurrence of PPC will be recorded as a collapsed composite of single adverse pulmonary events and represents the primary endpoint.

DISCUSSION

PROTHOR is the first randomized controlled trial in patients undergoing thoracic surgery with OLV that is adequately powered to compare the effects of intraoperative high PEEP with RM versus low PEEP without RM on PPC. The results of the PROTHOR trial will support anesthesiologists in their decision to set intraoperative PEEP during protective ventilation for OLV in thoracic surgery.

TRIAL REGISTRATION

The trial was registered in clinicaltrials.gov ( NCT02963025 ) on 15 November 2016.

Urban young women's preferences for intervention strategies to promote physical and mental health preconception: A Healthy Life Trajectories Initiative (HeLTI)

This study aimed to qualitatively investigate young women's preferences for preconception intervention strategies to promote physical and mental health in a rapidly transitioning, urban setting. Four semi-structured focus group discussions were conducted with young women (n = 29, 18–24 years old) from Soweto, South Africa. Qualitative data were thematically analysed. Two main themes were identified: 1) challenges and needs of intervention beneficiaries; and 2) preferences for intervention strategies (content and delivery). The challenges participants mentioned could be classified as those relating to social pressure, identity, and socioeconomic circumstances. Mental health support appeared to be a greater need than physical health, and this featured in their preferences for intervention content, although a number of physical health topics were also mentioned (healthy eating and contraception). Participants had mixed preferences for intervention materials, ranging from printed to electronic and mobile resources. Their preferences for intervention activities ranged from educational sessions, to fun and interactive practical activities, and activities they could take home. Community health workers (CHWs) were the preferred agent of delivery for interventions, though participants emphasised the importance of CHWs having appropriate interpersonal skills and own life experience. Some women preferred one-on-one sessions with a CHW, while others preferred group sessions. While recognising the value of family sessions, young women were less enthusiastic about this approach. These findings provide valuable formative data for developing effective interventions to optimise young women's preconception health in urban Africa. These contextual realities should be acknowledged when addressing key physical and mental health issues facing young women.

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Social pressure is a major challenge for young women in urban South Africa.

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Mental health should be a key feature of preconception interventions.

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Community health workers are the preferred agent of delivery in this context.

Abstract P6-14-03: Metastatic breast cancer alliance's patient education and access to trials: Perceptions and actions

Background

Those living with metastatic breast cancer (MBC) have distinct and shifting concerns in regard to education and decision making in considering clinical trials as a treatment option. Clinical trials designs, are becoming increasingly complex, and many patients have concerns for biomarker requirements Aims/Research Questions

· What is the status of MBCA advocacy members' and partners' digital information, education and access to metastatic breast cancer trials?

· What plans do MBCA members/partners have for the next 6-18 months to educate and inform their constituents for the 2018 rollout of BreastCancerTrials.org's (BCT)Metastatic Trial Search (MTS) and Metastatic Trial Talk (MTT) and other trial matching systems?

· What are the top 5 barriers regarding trial enrollment?

· What are best practices for MBC trial education?

Research Methodology and Design

A comprehensive analysis was conducted comprising both secondary and primary research to inform these specific aims. Secondary research was conducted using previous capture of MBCA online digital resources and strengthened to include additional research on MBCA members and partners online resources including pages specifically devoted to clinical trials and metastatic clinical trials.

Mixed methods approaches include:

1) An assessment of MBCA members' and partners' digital media presence regarding MBC trials using a standardized form and rating system, and an analysis of MBCA members 2017 use of MTS using BCT secondary data;

2) Structured, recorded interviews with selected MBCA members/ partners, sharing the results of the assessments and querying them regarding their future plans and perceived barriers; and

3) Mixed methods analyses of the interview recordings using DeDoose to assess and articulate key trends and perceptions.

Statistical Methods

Simple frequency percentages and means were used in the assessment rankings of the MBCA members. DeDoose was used to provide mixed method analyses of the MBCA member and partner interviews. Results

Analysis of the MBCA members and partners websites and digital media showed that, increasingly, both groups use the full variety of digital media to educate their constituents regarding MBC clinical trials. The 13 MBCA advocacy members providing online access to BreastCancerTrials' MTS in 2017 provided 97% of the traffic to the MTS trial matching service. System types accessing the MTS widget were 57.3% desktops, 28.6% mobile devices and 14% tablets. Table 1 shows assessment totals of 5 categories of the 13 MBCA advocacy group members' websites using MTS as compared to the 19 MBCA members not using the widget. Table 2 shows the 2017 usage of BCT's MTS with 97% of the page views coming from MBCA members.

Table 1.Assessment Ratings of MBCA Advocacy Partners on Metastatic Trial Education/AccessAwareness of Trials (e.g. explains trial Phases)Knowledge SharingInterest in Metastatic Breast CancerAction Potential for clinical trial access or enrollmentTotal (0-100)13 MBCA Advocate Members with MTS widget22.1523.0024.3124.1593.6219 MBCA Members without MTS widget13.2113.9513.5311.9552.16

Table 2.2017 Use Of Metastatic Trial SearchBCT's Metastatic Trial Search (MTS) Results2017Annual Page views33,360Unique Sessions14,295Show Trials8,100Show Trials by month675Average Time on Site (minutes)3:34Total Engagement Events5,006

Citation Format: Vollmer Dahlke DJ, Smith ML, Han G, Ory MG, Cohen E. Metastatic breast cancer alliance's patient education and access to trials: Perceptions and actions [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-14-03.

Gender differences in homocysteine concentrations, a population-based cross-sectional study

BACKGROUND AND AIMS

High concentrations of homocysteine are considered a risk factor for atherosclerosis and coronary artery disease. The aim of this study was to assess whether or not there are gender differences in the plasma concentrations of homocysteine.

METHODS AND RESULTS

Data were collected from medical records of individuals examined at a screening center in Israel between the years 2000-2014. Cross sectional analysis was carried out on 9237 men and 4353 women. Mean (SD) age of the study sample was 48.4 (9.7) and 47.7 (9.7) years for men and women respectively. Average homocysteine concentrations were 12.6 (5.9) and 9.6 (3.2) μmol/L in men and women respectively (p < 0.001). Prevalence of homocysteine concentrations above 15 μmol/L was found to be significantly higher in men than in women; 15.5% vs 3.9% respectively (p < 0.001). Low concentrations of vitamin (B12 < 200 pmol/L) and low concentrations of folate (<12 nmol/L) were found to be significantly higher in men than in women 20.4% vs. 16.0% and 18.5% vs. 10.8% respectively. Compared to women, men had a significantly higher odds ratio (95% CI) of having homocysteine concentrations above 15 μmol/L: non adjusted model, 4.47 (3.80-5.26); adjusted model for age, smoking status, body mass index, diabetes mellitus, kidney function and low serum concentrations of vitamin B12 and folate, 3.44 (2.89-4.09).

CONCLUSION

Plasma homocysteine concentrations are higher in men than in women. This may be a contributing factor to gender differences for developing atherosclerosis and coronary artery disease.

Comparison of Thrombelastography with Common Coagulation Tests

Thrombelastography, although proven as a useful research tool has not been evaluated for its clinical utility against common coagulation laboratory tests. In this study we compare the thrombelastographic measurements with six common tests (the hematocrit, platelet count, fibrinogen, prothrombin time, activated thromboplastin time and fibrin split products). For such comparisons, two samples of subjects were selected, 141 normal volunteers and 121 patients with cancer. The data was subjected to various statistical techniques such as correlation, ANOVA, canonical and discriminant analysis to measure the extent of the correlations between the two sets of variables and their relative strength to detect blood clotting abnormalities. The results indicate that, although there is a strong relationship between the thrombelastographic variables and these common laboratory tests, the thrombelastographic variables contain additional information on the hemostatic process.