Transport Variability of Very Short Lived Substances From the West Indian Ocean to the Stratosphere

Halogen- and sulfur-containing compounds are supersaturated in the surface ocean, which results in their emission to the atmosphere. These compounds can be transported to the stratosphere, where they impact ozone, the background aerosol layer, and climate. In this study we calculate the seasonal and interannual variability of transport from the West Indian Ocean (WIO) surface to the stratosphere for 2000-2016 with the Lagrangian transport model FLEXPART using ERA-Interim meteorological fields. We investigate the transport relevant for very short lived substances (VSLS) with tropospheric lifetimes corresponding to dimethylsulfide (1 day), methyl iodide (CH3I, 3.5 days), bromoform (CHBr3, 17 days), and dibromomethane (CH2Br2, 150 days). The stratospheric source gas injection of VSLS tracers from the WIO shows a distinct annual cycle associated with the Asian monsoon. Over the 16-year time series, a slight increase in source gas injection from the WIO to the stratosphere is found for all VSLS tracers and during all seasons. The interannual variability shows a relationship with sea surface temperatures in the WIO as well as the El Niño-Southern Oscillation. During boreal spring of El Niño, enhanced stratospheric injection of VSLS from the tropical WIO is caused by positive sea surface temperature anomalies and enhanced vertical uplift above the WIO. During boreal fall of La Niña, strong injection is related to enhanced atmospheric upward motion over the East Indian Ocean and a prolonged Indian summer monsoon season. Related physical mechanisms and uncertainties are discussed in this stud

Survival Increases with CPR by Emergency Medical Services before defibrillation of out-of-hospital ventricular fibrillation or ventricular tachycardia: Observations from the Resuscitation Outcomes Consortium

BACKGROUND: Immediate defibrillation is the traditional approach to resuscitation of cardiac arrest due to ventricular fibrillation or tachycardia (VF/VT). Delaying defibrillation to provide chest compressions may improve survival. We examined the effect of the duration of Emergency Medical Services (EMS) cardiopulmonary resuscitation (CPR) prior to first defibrillation on survival in patients with out-of-hospital VF/VT. MATERIALS AND METHODS: From a prospective multi-center observational registry of EMS-treated out-of-hospital cardiac arrest, we identified 1,638 EMS-treated cardiac arrests with first recorded rhythm VF/VT or “shockable” and complete data for analysis. Survival to hospital discharge was determined as a function of EMS CPR duration prior to first shock. RESULTS: Compared to the reference group of first EMS CPR duration ≤ 45 seconds, the odds of survival was greater among patients who received between 46 seconds to 195 seconds of EMS CPR before first shock (46 to 75 seconds odds ratio [OR] 1.15, 95% confidence interval [CI] 0.71-1.87; 76 to 105 seconds, OR 1.37, 95% CI 0.80-2.35; 106 to 135 seconds, OR 1.53, 95% CI 0.96-2.45; 136 to 165 seconds, OR 1.24, 95% CI 0.71-2.15; 166 to 195 seconds, OR 1.47, 95% CI 0.85-2.52). The benefit of EMS CPR before defibrillation was reduced when the duration of CPR exceeded 195 seconds (196 to 225 seconds, OR 0.95, 95% CI 0.47-1.81; 226 to 255 seconds, OR 0.91, 95% CI 0.46-1.79; 256 to 285 seconds, OR 0.46, 95% CI 0.17-1.29; 286 to 315 seconds, OR 1.29, 95% CI 0.59-2.85). An optimal EMS CPR duration was not identified and no duration achieved statistical significance. CONCLUSION: In this observational analysis of VF/VT arrest, between 46 and 195 seconds of EMS CPR prior to defibrillation was weakly associated with improved survival compared to ≤ 45 seconds. Randomized trials are needed to confirm the optimal duration of EMS CPR prior to defibrillation and to assess the impact of first CPR duration on all initial rhythms

Time to TAVI: streamlining the pathway to treatment

Introduction Severe aortic stenosis is a major cause of morbidity and mortality. The existing treatment pathway for transcatheter aortic valve implantation (TAVI) traditionally relies on tertiary Heart Valve Centre workup. However, this has been associated with delays to treatment, in breach of British Cardiovascular Intervention Society targets. A novel pathway with emphasis on comprehensive patient workup at a local centre, alongside close collaboration with a Heart Valve Centre, may help reduce the time to TAVI.Methods The centre performing local workup implemented a novel TAVI referral pathway. Data were collected retrospectively for all outpatients referred for consideration of TAVI to a Heart Valve Centre from November 2020 to November 2021. The main outcome of time to TAVI was calculated as the time from Heart Valve Centre referral to TAVI, or alternative intervention, expressed in days. For the centre performing local workup, referral was defined as the date of multidisciplinary team discussion. For this centre, a total pathway time from echocardiographic diagnosis to TAVI was also evaluated. A secondary outcome of the proportion of referrals proceeding to TAVI at the Heart Valve Centre was analysed.Results Mean±SD time from referral to TAVI was significantly lower at the centre performing local workup, when compared with centres with traditional referral pathways (32.4±64 to 126±257 days, p<0.00001). The total pathway time from echocardiographic diagnosis to TAVI for the centre performing local workup was 89.9±67.6 days, which was also significantly shorter than referral to TAVI time from all other centres (p<0.003). Centres without local workup had a significantly lower percentage of patients accepted for TAVI (49.5% vs 97.8%, p<0.00001).Discussion A novel TAVI pathway with emphasis on local workup within a non-surgical centre significantly reduced both the time to TAVI and rejection rates from a Heart Valve Centre. If adopted across the other centres, this approach may help improve access to TAVI