Hypothermia and Prolonged Time From Procedure End to Extubation After Endovascular Thoracic Aortic Surgery.

OBJECTIVE: Perioperative hypothermia (core temperature <36°C) occurs in 50%-to-80% of patients recovering from thoracic aortic surgery, though its effects have not been described fully in this context. The authors, therefore, sought to characterize the incidence of perioperative hypothermia and its association with time from procedure end to extubation in endovascular aortic surgical patients. DESIGN: A retrospective cohort study. SETTING: At a single academic tertiary center. PARTICIPANTS: Patients recovering from thoracic aortic surgery with lumbar drains. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: A total of 196 patients were included in this study, 55 of whom were hypothermic with temperatures <35.0°C at the end of surgery. Though the unadjusted time to extubation was not statistically different in the hypothermic group (median 8 minutes, IQR 5-13.5 minutes) compared to the normothermic group (median 7 minutes, IQR 4-12 minutes; p = 0.062), multivariate predictors of increased time from procedure end to extubation included hypothermia (p = 0.011), age (p = 0.009), diabetes (p = 0.015), history of carotid disease (p = 0.040), and crystalloid volume (p = 0.019). CONCLUSIONS: Hypothermia in patients recovering from endovascular aortic surgery was associated with prolonged time from procedure end to extubation. Because of the retrospective observational nature of the authors' analysis, it was not possible to determine the extent to which prolonged mechanical ventilation was influenced by low temperature.

Reliability of the longitudinal experts all data (LEAD) methodology for determining the presence of elder mistreatment.

Developing reliable screening tools to identify elder mistreatment requires an accurate and reproducible reference standard. This study sought to investigate the reliability of the Longitudinal, Experts, All Data (LEAD) methodology as a reference standard in confirming presence of elder mistreatment. We analyzed data from a large, emergency department-based study that used a LEAD panel to determine the reference standard. For this study, a second, blinded LEAD panel reviewed clinical material for 40 patients. For each panel, five content experts voted on whether elder mistreatment was present. We found moderate agreement between the two LEAD panels in determining presence of elder mistreatment: 85% agreement; k = 0.58; 95% Confidence Interval 0.28-0.87. Individual raters for both LEAD panels reported being mostly certain or certain >90% of votes. Efforts to further characterize and improve the reliability of the LEAD methodology in this context are warranted.

Rapid conversion of an oceanic spreading center to a subduction zone inferred from high-precision geochronology.

Where and how subduction zones initiate is a fundamental tectonic problem, yet there are few well-constrained geologic tests that address the tectonic settings and dynamics of the process. Numerical modeling has shown that oceanic spreading centers are some of the weakest parts of the plate tectonic system [Gurnis M, Hall C, Lavier L (2004) Geochem Geophys Geosys 5:Q07001], but previous studies have not favored them for subduction initiation because of the positive buoyancy of young lithosphere. Instead, other weak zones, such as fracture zones, have been invoked. Because these models differ in terms of the ages of crust that are juxtaposed at the site of subduction initiation, they can be tested by dating the protoliths of metamorphosed oceanic crust that is formed by underthrusting at the beginning of subduction and comparing that age with the age of the overlying lithosphere and the timing of subduction initiation itself. In the western Philippines, we find that oceanic crust was less than ∼1 My old when it was underthrust and metamorphosed at the onset of subduction in Palawan, Philippines, implying forced subduction initiation at a spreading center. This result shows that young and positively buoyant, but weak, lithosphere was the preferred site for subduction nucleation despite the proximity of other potential weak zones with older, denser lithosphere and that plate motion rapidly changed from divergence to convergence.