ASAIO journal : a peer-reviewed journal of the American Society for Artificial Internal Organs
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Comparative Study
Experimental validation of cardiac index measurement using transpulmonary thermodilution technique in neonatal total liquid ventilation.
This study aimed to assess the precision and the interchangeability of cardiac index measurement by transpulmonary thermodilution (TPTD) and pulmonary thermodilution (PTD) devices on a neonatal animal model of acute respiratory distress syndrome under total liquid ventilation (TLV) and conventional mechanical ventilation (CMV). After acute respiratory distress induction by tracheal instillation of hydrochloric acid, transpulmonary (CI(TPTD)) and pulmonary (CI(PTD)) cardiac index were simultaneously measured every 30 minutes for a 240-minute experiment. Reproducibility of both thermodilution techniques was very good to excellent in both groups of ventilation with intrainstrument intraclass correlation coefficient >0.60. ⋯ Bias between TPTD and PTD was not statistically different in TLV than in CMV (p = 0.11). Transpulmonary thermodilution and PTD remained precise but not interchangeable techniques under TLV as well as CMV. Because TLV does not bring additional bias between both thermodilution techniques, we advocate the use of the less-invasive TPTD under TLV as currently recommended in CMV.
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Assessment of cardiac output (CO) is crucial in the management of the critically ill, especially in post cardiac surgery intensive care unit (ICU) patients. In this study, we validated CO measured by the novel ultrasound dilution (COUD) with those measured by pulmonary artery (PA) thermodilution (COTD) in 26 adult post cardiac surgery patients. For COUD, blood was circulated through an extracorporeal arteriovenous (AV) loop from the radial artery catheter to the introducer of PA catheter for 5-8 minutes. ⋯ Bias and precision (mean difference ± 2SDs) was -0.004 ± 1.34 L/min between the two methods. The percentage error (2SD/mean) was 22.2%, which is below the clinically acceptable limit (<30%). Cardiac output measured by ultrasound dilution and thermodilution methods agreed well in post cardiac surgery ICU patients and hence can be interchangeably used.
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The minimized extracorporeal circulation (ECC) is a safe alternative for coronary artery bypass grafting (CABG) and allows a reduction of the negative effects associated with conventional extracorporeal circulation. Experimental and clinical data indicate that the anesthetic regime might influence the ischemia-reperfusion injury in CABG surgery. The aim of our retrospective study was to investigate the cardioprotective effects of two different minimized ECC systems in combination with two different anesthetic concepts and to determine the impact on oxygen consumption during aortic cross-clamping (ACC). ⋯ During the period of ACC, the values of systemic vascular resistance (SVR) were higher in SEVO group (p < 0.005). Also, the SEVO group showed lower oxygen consumption at each time point ACC (p < 0.0001). In conclusion, PRECiSe system using a microporous capillary oxygenator in combination with sevoflurane-based volatile anesthetic regimen seem to provide lower postoperative myocardial cell damage and to allow improved perfusion with higher SVRs and lower oxygen consumption during ACC.
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Ventricular assist devices (VADs) and intra-aortic balloon pumps (IABPs) are important tools that provide hemodynamic support to patients in cardiogenic shock. The Impella Recover 2.5 is a percutaneous VAD that provides temporary circulatory support. We report the case of a patient who required the combined support of both an IABP and the Impella device.
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Comparative Study
Comparative analysis of von Willebrand factor profiles in pulsatile and continuous left ventricular assist device recipients.
A higher rate of nonsurgical bleeding has been observed in nonpulsatile left ventricular assist device (LVAD) recipients. von Willebrand factor (vWF) profiles were compared for nonpulsatile and pulsatile LVAD recipients to explore mechanisms that may contribute to the development of postimplant nonsurgical bleeding. The nonpulsatile mechanism may impair vWF function by creating a deficiency in vWF high molecular weight multimers (HMWMs), essential for hemostasis. High molecular weight multimer deficiency should result in low ristocetin cofactor (RCo) to vWF antigen ratios (vWF:RCo/vWF:Ag) because of impaired platelet (plt)-binding ability. von Willebrand factor profiles and HMWM were measured pre- and post-LVAD placement in 11 nonpulsatile (HeartMate II [HM II[) and 3 pulsatile (HeartMate XVE [HM XVE]) recipients. ⋯ Similar results were not observed in our small series of pulsatile HM XVE recipients. This finding could suggest a contributing factor to the increase in nonsurgical bleeding observed in nonpulsatile LVAD patients. Further investigation is ongoing to identify specific causes of vWF impairment.