High resolution imaging and five-year tuberculosis contact outcomes.

Background: The evolution of tuberculosis (TB) disease during the clinical latency period remains incompletely understood. Methods: 250 HIV-uninfected, adult household contacts of rifampicin-resistant TB with a negative symptom screen underwent baseline 18F-Fluorodeoxyglucose positron emission and computed tomography (PET/CT), repeated in 112 after 5-15 months. Following South African and WHO guidelines, participants did not receive preventive therapy. All participants had intensive baseline screening with spontaneous, followed by induced, sputum sampling and were then observed for an average of 4.7 years for culture-positive disease. Baseline PET/CT abnormalities were evaluated in relation to culture-positive disease. Results: At baseline, 59 (23.6%) participants had lung PET/CT findings consistent with TB of which 29 (11.6%) were defined as Subclinical TB, and 30 (12%) Subclinical TB-inactive. A further 83 (33.2%) had other lung parenchymal abnormalities and 108 (43.2%) had normal lungs. Over 1107-person years of follow-up 14 cases of culture-positive TB were diagnosed. Six cases were detected by intensive baseline screening, all would have been missed by the South African symptom-based screening strategy and only one detected by a WHO-recommended chest X-Ray screening strategy. Those with baseline Subclinical TB lesions on PET/CT were significantly more likely to be diagnosed with culture-positive TB over the study period, compared to those with normal lung parenchyma (10/29 [34.5%] vs 2/108 [1.9%], Hazard Ratio 22.37 [4.89-102.47, p<0.001]). Conclusions: These findings challenge the latent/active TB paradigm demonstrating that subclinical disease exists up to 4 years prior to microbiological detection and/or symptom onset. There are important implications for screening and management of TB.

Towards integrated modeling of the long-term impacts of oil spills.

Although great progress has been made to advance the scientific understanding of oil spills, tools for integrated assessment modeling of the long-term impacts on ecosystems, socioeconomics and human health are lacking. The objective of this study was to develop a conceptual framework that could be used to answer stakeholder questions about oil spill impacts and to identify knowledge gaps and future integration priorities. The framework was initially separated into four knowledge domains (ocean environment, biological ecosystems, socioeconomics, and human health) whose interactions were explored by gathering stakeholder questions through public engagement, assimilating expert input about existing models, and consolidating information through a system dynamics approach. This synthesis resulted in a causal loop diagram from which the interconnectivity of the system could be visualized. Results of this analysis indicate that the system naturally separates into two tiers, ocean environment and biological ecosystems versus socioeconomics and human health. As a result, ocean environment and ecosystem models could be used to provide input to explore human health and socioeconomic variables in hypothetical scenarios. At decadal-plus time scales, the analysis emphasized that human domains influence the natural domains through changes in oil-spill related laws and regulations. Although data gaps were identified in all four model domains, the socioeconomics and human health domains are the least established. Considerable future work is needed to address research gaps and to create fully coupled quantitative integrative assessment models that can be used in strategic decision-making that will optimize recoveries from future large oil spills.

A retrospective study of pulseless electrical activity, bedside ultrasound identifies interventions during resuscitation associated with improved survival to hospital admission. A REASON Study.

OBJECTIVE: Our objective was to determine whether organized or disorganized cardiac activity is associated with increased survival in patients who present in pulseless electrical activity (PEA) treated with either 1) standard advanced cardiac life support (ACLS) medications or 2) other interventions. METHODS: This was a secondary analysis of a prospective, multi-center observational study utilizing ultrasound in out-of-hospital or inemergency department PEA arrest. Bedside ultrasound was performed as ACLS protocol started and during pulse checks. Only cases with visible cardiac activity on ultrasound were included in the present analysis. Cardiac activity was categorized as disorganized (agonal twitching) or organized (contractions with changes in ventricular dimensions). Patients were categorized as receiving either standard bolus ACLS medications or alternative medications during the resuscitation (continuous adrenergic agents, thrombolytics, others). The primary outcome was survival to hospital admission. The secondary outcome was return of spontaneous circulation (ROSC). Multivariate modeling was performed to assess association between survival to hospital admission in patients with intravenous adrenergic agents and cardiac activity. RESULTS: In our cohort of 225 patients in PEA cardiac arrest with cardiac activity on ultrasound, the overall survival rate was higher in patients with organized cardiac activity than with disorganized cardiac activity. PEA cardiac arrest patients with organized cardiac activity treated with standard ACLS interventions demonstrated improved survival to hospital admission compared to those with disorganized activity (37.7% (95%CI 24.8-50.2%) versus 17.9% (95%CI 10.9-28%). PEA cardiac arrest patients with organized cardiac activity who received continuous adrenergic agents during the resuscitation and prior to ROSC demonstrated higher survival to hospital admission 45.5% (95%CI 26.9-65.4%) and ROSC 90.9% (95%CI 71.0-98.7%) compared to those with disorganized cardiac activity who received continuous adrenergic agents during the resuscitation 0% (95%CI 0-23.0%) and 47.1% (95%CI 26-69%). Regression analysis demonstrates an association between increased survival in patients receiving intravenous adrenergic agents and organized cardiac activity. CONCLUSION: Survival in patients following PEA arrest is higher in patients with organized cardiac activity. The initiation of continuous adrenergic agents during PEA was associated with improved survival to hospital admission in patients with organized cardiac activity on bedside ultrasound, but this improvement was not seen in patients in PEA with disorganized cardiac activity. Bedside ultrasound may identify a subset of patients that respond differently to ACLS interventions.

Emergency department point-of-care ultrasound in out-of-hospital and in-ED cardiac arrest.

BACKGROUND: Point-of-care ultrasound has been suggested to improve outcomes from advanced cardiac life support (ACLS), but no large studies have explored how it should be incorporated into ACLS. Our aim was to determine whether cardiac activity on ultrasound during ACLS is associated with improved survival. METHODS: We conducted a non-randomized, prospective, protocol-driven observational study at 20 hospitals across United States and Canada. Patients presenting with out-of-hospital arrest or in-ED arrest with pulseless electrical activity or asystole were included. An ultrasound was performed at the beginning and end of ACLS. The primary outcome was survival to hospital admission. Secondary outcomes included survival to hospital discharge and return of spontaneous circulation. FINDINGS: 793 patients were enrolled, 208 (26.2%) survived the initial resuscitation, 114 (14.4%) survived to hospital admission, and 13 (1.6%) survived to hospital discharge. Cardiac activity on US was the variable most associated with survival at all time points. On multivariate regression modeling, cardiac activity was associated with increased survival to hospital admission (OR 3.6, 2.2-5.9) and hospital discharge (OR 5.7, 1.5-21.9). No cardiac activity on US was associated with non-survival, but 0.6% (95% CI 0.3-2.3) survived to discharge. Ultrasound identified findings that responded to non-ACLS interventions. Patients with pericardial effusion and pericardiocentesis demonstrated higher survival rates (15.4%) compared to all others (1.3%). CONCLUSION: Cardiac activity on ultrasound was the variable most associated with survival following cardiac arrest. Ultrasound during cardiac arrest identifies interventions outside of the standard ACLS algorithm.

Intensive point-of-care ultrasound training with long-term follow-up in a cohort of Rwandan physicians.

OBJECTIVE: We delivered a point-of-care ultrasound training programme in a resource-limited setting in Rwanda, and sought to determine participants' knowledge and skill retention. We also measured trainees' assessment of the usefulness of ultrasound in clinical practice. METHODS: This was a prospective cohort study of 17 Rwandan physicians participating in a point-of-care ultrasound training programme. The follow-up period was 1 year. Participants completed a 10-day ultrasound course, with follow-up training delivered over the subsequent 12 months. Trainee knowledge acquisition and skill retention were assessed via observed structured clinical examinations (OSCEs) administered at six points during the study, and an image-based assessment completed at three points. RESULTS: Trainees reported minimal structured ultrasound education and little confidence using point-of-care ultrasound before the training. Mean scores on the image-based assessment increased from 36.9% (95% CI 32-41.8%) before the initial 10-day training to 74.3% afterwards (95% CI 69.4-79.2; P < 0.001). The mean score on the initial OSCE after the introductory course was 81.7% (95% CI 78-85.4%). The mean OSCE performance at each subsequent evaluation was at least 75%, and the mean OSCE score at the 58-week follow up was 84.9% (95% CI 80.9-88.9%). CONCLUSIONS: Physicians providing acute care in a resource-limited setting demonstrated sustained improvement in their ultrasound knowledge and skill 1 year after completing a clinical ultrasound training programme. They also reported improvements in their ability to provide patient care and in job satisfaction.