Levosimendan and Global Longitudinal Strain Assessment in Sepsis (GLASSES 1): a study protocol for an observational study.

INTRODUCTION: Cardiogenic shock is a condition of low cardiac output that represents the end stage of a progressive deterioration of cardiac function. The main cause is ischaemic heart disease, but there are several non-ischaemic causes, including sepsis. The use of levosimendan in cardiogenic shock during sepsis is still under debate. METHODS: We are conducting an observational, single-centre, not-for-profit study enrolling patients aged 18-80 years old admitted to the intensive care unit with a diagnosis of septic shock. Patients will be monitored with the EV1000/VolumeView device (Edwards Lifesciences, Irvine, USA). Patients with cardiac index (CI) values <2.5 L/min/m2 and/or stroke volume index (SVI) <30 mL/beat/m2 are considered eligible for the study. Enrolled participants will undergo an echocardiographic examination using the Vivid S6 ultrasound machine (General Electric, Northville, Michigan) and a 3.6 MHz cardiology probe through which the apical projections of chambers 2, 3 and 4 will be acquired; this is necessary to calculate the global longitudinal strain (GLS) using EchoPAC* Clinical Workstation Software (General Electric). A dobutamine infusion will be started in these patients; 24 hours later CI and SVI will be recalculated using EV1000/VolumeView and then a levosimendan infusion will begin for 24 hours. Once the infusion cycle of the calcium-sensitising drug has been carried out, the infusion of dobutamine will be reduced until it stops, and the CI, SVI, GLS and arterial elastance (Ea):Ventricular Elastance (Ees) will be re-evaluated. The primary endpoint is recovery of GLS ≥15% and the secondary endpoint is a relative reduction in mortality of 15%. ETHICS AND DISSEMINATION: The investigators declare that the study will be conducted in full compliance with international regulations (EU Directive 2016/679/EC) and national implementation (DM 15 July 1997; 211/2003; 200/2007) regarding the clinical trial and the principles of the Declaration of Helsinki. Study results will be disseminated through peer-reviewed journals and conferences. Ethical approval for this study has been given by Comitato Etico Regione Toscana - Area Vasta Centro, Florence, Italy (ethical committee number: 13875_oss) on 25 May 2019 (Chairperson Professor Marco Marchi). TRIAL REGISTRATION NUMBER: NCT04141410.

Blood flow maintenance by cardiac massage during cardiopulmonary resuscitation: Classical theories, newer hypotheses, and clinical utility of mechanical devices.

The mechanisms by which closed chest cardiac massage produces and maintains blood flow during cardiopulmonary resuscitation are still debated. To date, two main theories exist: the "cardiac pump", which assumes that blood flow is driven by direct cardiac compression and the "chest pump", which hypothesizes that blood flow is caused by changes in intrathoracic pressure. Newer hypotheses including the "atrial pump", the "lung pump", and the "respiratory pump" were also proposed. We reviewed studies supporting these different theories as well as the clinical evidences on the utility of mechanical devices proposed to optimize cardiopulmonary resuscitation, in view of their pathophysiological assumptions with regard to the underlying theory. On the basis of current evidence, a single theory is probably not sufficient to explain how cardiac massage produces blood flow. This suggests that different simultaneous mechanism might be involved. The relative importance of these mechanisms depends on several factors, including delay from collapse to starting of resuscitation, compression force and rate, body habitus, airway pressure, and presenting electrocardiogram. The complexity of the physiologic events occurring during cardiopulmonary resuscitation, together with the need of adequate training for a correct and prompt utilization of mechanical devices, might also partially explain the disappointing results of these devices in most clinical studies.

Speckle tracking echocardiography and right ventricle dysfunction in acute respiratory distress syndrome a pilot study.

PURPOSE: Speckle tracking echocardiography is a novel echocardiographic technique to assess RV myocardial function but no data are so far available in patients with acute respiratory distress syndrome (ARDS), and we aimed at assessing the feasibility of 2 dimensional (2D) speckle tracking echocardiography and the prognostic role of RV free wall speckle tracking strain in 30 consecutive patients with moderate-severe ARDS MATERIALS AND METHODS: In an observational prospective study, 30 consecutive patients with moderate-severe ARDS were enrolled. Echocardiography was performed within 12 hours from ICU admission. RESULTS: Mortality rate was 33% (10/30). Non-survivors showed lower values of pH (7.32 ± 0.09, P = 0.03) and higher troponin I levels (0.32 (0.08-0.46), P = 0.04), NT-pro BNP (3091 (2662-7128), P = 0.009), and SAPS II (60.3 ± 9.6, P < 0.001). At echocardiographic examination, non-survivors showed lower values of TAPSE (18.3 ± 3, P = 0.034) and higher systolic pulmonary arterial pressure (49.6 ± 16, P = 0.05). Two patients (6.6%) did not show valid acoustic windows. Only three patients showed normal values of RV strain free wall (22%, 25%, and 28% absolute values, respectively), among whom one patient died. When compared to survivors, non-survivors showed significantly lower values of RV strain free wall (-10.4 ± 0.10, P < 0.001). CONCLUSIONS: In mechanically ventilated moderate-severe ARDS, 2D speckle tracking is feasible even though difficult acoustic windows are common. Further studies are needed to confirm our findings in a larger cohort of patients.