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Introduction: Well-timed explant of veno-arterial extracorporeal life support (V-A ECLS) depends on adequate assessment of cardiac recovery. Often, evaluation of cardiac recovery consists of reducing support flow while visualizing cardiac response using transoesophageal echocardiography (TEE). This method, however, is time consuming and based on subjective findings. The dynamic filling index (DFI) may aid in the quantitative assessment of cardiac load-responsiveness. The dynamic filling index is based on the relationship of support flow and pump speed, which varies with varying hemodynamic conditions. This case series intends to investigate whether the DFI may support TEE in facilitating the assessment of cardiac load-responsiveness. Methods: Measurements for DFI-determination were performed in seven patients while simultaneously assessing ventricular function by measuring the aortic velocity time integral (VTI) using TEE. Measurements consisted of multiple consecutive transient speed manipulations (∼100 r/min) during weaning trials, both at full support and during cardiac reloading at reduced support. Results: The VTI increased between full and reduced support in six weaning trials. In five of these trials DFI decreased or remained equal, and in one case DFI increased. Of the three trials in which VTI decreased between full and reduced support, DFI increased in two cases and decreased in one case. Changes in DFI, however, are mostly smaller than the detection threshold of 0.4 mL/rotation. Conclusion: Even though current level of accuracy of the parameter requires further investigation to increase reliability and possibly predictability, DFI seems likely to be a potential parameter in supporting TEE for the assessment of cardiac load-responsiveness. [ABSTRACT FROM AUTHOR]

Background: This study aimed to describe the efficacy of veno-arterial extracorporeal life support (VA-ECLS) through early lactate clearance and pH restoration and assess the potential association with 30-day survival following hospital discharge. Methods: Data of patients receiving VA-ECLS for at least 24 h were retrospectively compiled. Blood lactate levels, liver enzymes, and kidney parameters prior to VA-ECLS initiation and at 2, 8, 14, 20, and 26 h of support had been recorded as part of clinical care. The primary outcome was 30-day survival. Results: Of 77 patients who underwent VA-ECLS for refractory cardiogenic shock, 44.2% survived. For all non-survivors, ECLS was initiated after eight hours (p =.008). Blood pH was significantly higher in survivors compared to non-survivors at all time points except for pre-ECLS. Lactate levels were significantly lower in survivors (median range 1.95-4.70 vs 2.90-6.70 mmol/L for survivors vs non-survivors, respectively). Univariate and multivariate analyses indicated that blood pH at 24 h (OR 0.045, 95% CI: 0.005-0.448 for pH <7.35, p =.045) and lactate concentration pre-ECLS (OR 0.743, 95% CI: 0.590-0.936, p =.012) were reliable predictors for 30-day survival. Further, ischemic cardiogenic shock as ECLS indication showed 36.2% less lactate clearance compared to patients with other indications such as arrhythmia, postcardiotomy, and ECPR. Conclusion: ECLS showed to be an effective treatment in reducing blood lactate levels in patients suffering from refractory cardiogenic shock in which the outcome is influenced by the initial lactate level and pH in the early phase of the intervention. [ABSTRACT FROM AUTHOR]

The authors concluded that serum lactate levels are an important prognostic biomarker for 30-day mortality in cardiogenic shock patients treated with temporary mechanical circulatory support, i.e., the Impella CP device or venoarterial extracorporeal membrane oxygenation (ECMO). The recent study by Scolari et al. [[1]] entitled 'Association between serum lactate levels and mortality in patients with cardiogenic shock receiving mechanical circulatory support: a multicenter retrospective cohort study', published in the I BMC Cardiovascular Disorders i evaluates the prognostic role of serum lactate and lactate clearance over time in cardiogenic shock patients treated with mechanical circulatory support. [Extracted from the article]

The article discusses the study on extracorporeal life support (ELS) for patients with severe refractory cardiogenic shock (SRCS), refractory cardiac arrest and severe respiratory failure in a single centre between September 2007 and September 2012. Findings discussed include early ELS application to help in lowering mortality and morbidity in patients, and association of venoarterial ELS initiation delay and increased pre-ELS pH and lactate levels to death in cardiomyopathy patients.

The article presents a study on centrifugal pumps in relation of to low-flow extracorporeal CO2 removal. Topics include a look into hydrodynamic performance and gaseous microemboli (GME) activity of the pumps, the hydrodynamic stability of Rotassist 2.8 and Rotaflow 32 centrifugal pumps, and the technique called extracorporeal life support (ELS). It also mentions the net positive suction head (NPSH).

The article presents an in vitro study aimed at measuring the efficacy and safety of several pump control modalities combined with a volume buffer capacity (VBC) on centrifugal pump-based extracorporeal life support (ELS) stability and gaseous microemboli (GME) load during conditions of simulated hypovolemia. It concludes that flow and pressure servo control for ELS demonstrate evident deficits in preserving stable and safe ELS flow during hypovolemia.

Although a growing body of evidence indicates superiority of minimized cardiopulmonary bypass (mCPB) systems over conventional CPB systems, limited venous return can result in severe fluctuations of venous line pressure which can result in gaseous emboli. In this study, we investigated the influence of sub-atmospheric pressures and volume buffer capacity added to the venous line on the generation of gaseous emboli in the mCPB circuit.Two different mCPB systems (MEC - Maquet, n=7 and ECC.O - Sorin, n=8) and a conventional closed cardiopulmonary bypass (cCPB) system (n=12) were clinically evaluated. In the search for a way to increase volume buffer capacity of mCPB systems, we additionally evaluated the ‘Better Bladder’ (BB) in a mock circulation by simulating, repeatedly, decreased venous return while measuring pressure and gaseous embolic activity.Arterial gaseous emboli activity during clinical perfusion with a cCPB system was the lowest in comparison to the mCPB systems (312±465 versus 311±421 with MEC and 1,966±1,782 with ECC.O, counts per 10 minute time interval, respectively; p=0.03). The average volume per bubble in the arterial line was the highest in cases with cCPB (12.5±8.3 nL versus 8.0±4.2 nL with MEC and 4.6±4.8 nL with ECC.O; p=0.04 for both). Significant cross-correlation was obtained at various time offsets from 0 to +35 s between sub-atmospheric pressure in the venous line and gaseous emboli activity in both the venous and arterial lines. The in vitro data showed that incorporation of the BB dampens fluctuations of venous line pressure by approximately 30% and decreases gaseous emboli by up to 85%.In conclusion, fluctuations of sub-atmospheric venous line pressure during kinetic-assisted drainage are related to gaseous emboli. Volume buffer capacity added to the venous line can effectively dampen pressure fluctuations resulting from abrupt changes in venous return and, therefore, can help to increase the safety of minimized cardiopulmonary bypass by reducing gaseous microemboli formation resulting from degassing. [ABSTRACT FROM PUBLISHER]

The hypothesis was tested whether retrograde autologous priming (RAP) of the cardiopulmonary bypass system, compared to a standard primed system (NON-RAP group), results in less haemodilution and less transfusion of packed red blood cells. Retrospectively, data was collected from the medical charts of one hundred patients undergoing elective coronary artery bypass grafting using cardiopulmonary bypass. Fifty patients where RAP was used have been compared to fifty patients using NON-RAP. The prime volume in the NON-RAP group was 1,627±108 mL versus 782±96 mL in the RAP group (p<0.001). The lowest haematocrit during perfusion was 22% in the NON-RAP group versus 26% when the RAP technique was used (p<0.001). In the NON-RAP group, 26% of the patients received packed red cells in contrast to 6% in the RAP group (p<0.012). A positive association was found between RAP and less transfusion of packed red blood cells (p<0.012). In conclusion, retrograde autologous priming, reducing the prime volume of the cardiopulmonary bypass system, causes less haemodilution and reduces intraoperative transfusion of packed red blood cells. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Veno-right ventricular cannulation reduces recirculation in extracorporeal membrane oxygenation," by S. Lindstrom and colleagues published in a 2012 issue of "Perfusion."

The authors highlight the editorial "Why look backwards?" by Mark Kurusz within the issue, and discuss extracorporeal life support. They state that in spite of enormous progress in equipment used in extracorporeal life support, routine cardiopulmonary bypass procedures can have successful outcomes only if perfusion technology is at par, which is usually not the case. The authors emphasize on the need to combine knowledge from all fields into a single discipline of cardiovascular perfusion.