Q59102520
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The growth in the experimental research of facilities to support extracorporeal circulation requires the further development of models of acute heart failure that can be well controlled and reproduced. Two types of acute heart failure were examined in domestic pigs (Sus scrofa domestica): a hypoxic model (n=5) with continuous perfusion of the left coronary artery by hypoxic deoxygenated blood and ischemic model (n=9) with proximal closure of the left coronary artery and controlled hypoperfusion behind the closure. The aim was a severe, stable heart pump failure defined by hemodynamic parameters changes: a) decrease in cardiac output by at least 50 %; b) decrease in mixed venous blood saturation to under 60 %; c) left ventricular ejection fraction below 25 %; and d) decrease in flow via the carotid arteries at least 50 %. Acute heart failure developed in the first group in one animal with no acute mortality and in the second group in 8 animals with no acute mortality. In the case of ischemic model the cardiac output fell from 6.70+/-0.89 l/min to 2.89+/-0.75 l/min. The saturation of the mixed venous blood decreased from 83+/-2 % to 58+/-8 %. The left ventricular ejection fraction decreased from 50+/-8 % to 19+/-2 %. The flow via the carotid arteries decreased from 337+/-78 ml/min to 136+/-59 ml/min (P
Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a method used for the treatment most severe cases of decompensated heart failure. The purpose of this study was to evaluate the risk of the formation of microembolisms during VA-ECMO-based therapy. Heart failure was induced with simultaneous detection of microembolisms and the measurement of blood flow rate in the common carotid artery (CCA) without VA-ECMO (0 l/min) and at the VA-ECMO blood flow rate of 1, 2, 3 and 4 l/min. If embolisms for VA-ECMO 0 l/min and the individual regimes for VA-ECMO 1, 2, 3, 4 l/min are compared, a higher VA-ECMO flow rate is accompanied by a higher number of microembolisms. The final microembolism value at 16 min was for the VA-ECMO flow rate of 0 l/min 0.0 (0, 1), VA-ECMO l/min 7.5 (4, 19), VA-ECMO 2 l/min 12.5 (4, 26), VA-ECMO 3 l/min, 21.0 (18, 57) and VA-ECMO 4 l/min, 27.5 (21, 64). Such a comparison is statistically significant if VA-ECMO 0 vs. 4 l/min p<0.0001, 0 vs. 3 l/min p<0.01 and 1 vs. 4 l/min p<0.01 are compared. The results confirm that high VA-ECMO flow rates pose a risk with regards to the formation of a significantly higher number of microemboli in the blood circulation and that an increase in blood flow rates in the CCA corresponds to changes in the VA-ECMO flow rates.
- MeSH
- akutní nemoc MeSH
- arteria carotis communis diagnostické zobrazování patofyziologie MeSH
- embolie diagnostické zobrazování patofyziologie MeSH
- mikrocirkulace fyziologie MeSH
- mimotělní membránová oxygenace škodlivé účinky trendy MeSH
- modely nemocí na zvířatech * MeSH
- prasata MeSH
- rychlost toku krve fyziologie MeSH
- srdeční selhání diagnostické zobrazování patofyziologie terapie MeSH
- ultrasonografie dopplerovská metody trendy MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Venoarterial extracorporeal membrane oxygenation (VA ECMO) is widely used in treatment of decompensated heart failure. Our aim was to investigate its effects on regional perfusion and tissue oxygenation with respect to extracorporeal blood flow (EBF). In five swine, decompensated low-output chronic heart failure was induced by long-term rapid ventricular pacing. Subsequently, VA ECMO was introduced and left ventricular (LV) volume, aortic blood pressure, regional arterial flow and tissue oxygenation were continuously recorded at different levels of EBF. With increasing EBF from minimal to 5 l/min, mean arterial pressure increased from 47+/-22 to 84+/-12 mm Hg (P<0.001) and arterial blood flow increased in carotid artery from 211+/-72 to 479+/-58 ml/min (P<0.01) and in subclavian artery from 103+/-49 to 296+/-54 ml/min (P<0.001). Corresponding brain and brachial tissue oxygenation increased promptly from 57+/-6 to 74+/-3 % and from 37+/-6 to 77+/-6 %, respectively (both P<0.01). Presented results confirm that VA ECMO is a capable form of heart support. Regional arterial flow and tissue oxygenation suggest that partial circulatory support may be sufficient to supply brain and peripheral tissue by oxygen.
- MeSH
- arteria femoralis metabolismus MeSH
- arteria subclavia metabolismus MeSH
- arteriae carotides metabolismus MeSH
- chronická nemoc MeSH
- koronární cévy metabolismus MeSH
- mimotělní membránová oxygenace metody MeSH
- oxymetrie metody MeSH
- prasata MeSH
- rychlost toku krve fyziologie MeSH
- srdeční selhání metabolismus terapie MeSH
- vena femoralis metabolismus MeSH
- výsledek terapie MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The aims were to explore the effect of head-up tilt (HUT) to 30 and 60 degrees on hemodynamics and tissue oxygenation in anesthetized healthy swine. The data serve as a reference for a study of resuscitation efficacy at HUT such as during transport. Nine healthy swine (49+/-4 kg) were anesthetized and multiple sensors including myocardial pressure-volume loops catheter, carotid flow probe, blood pressure catheters, near infrared spectroscopy (NIRS) tissue oximetry and mixed venous oximetry (SVO2) catheter were introduced and parameters continuously recorded. Experimental protocol consisted of baseline in supine position (15 min), 30 degrees HUT (15 min), recovery at supine position (15 min) and 60 degrees HUT (5 min). Vacuum mattress was used for body fixation during tilts. We found that 30 and 60 degrees inclination led to significant immediate reduction in hemodynamic and oximetry parameters. Mean arterial pressure (mm Hg) decreased from 98 at baseline to 53 and 39, respectively. Carotid blood flow dropped to 47 % and 22 % of baseline values, end diastolic volume to 49 % and 53 % and stroke volume to 47 % and 45 % of baseline. SVO2 and tissue oximetry decreased by 17 and 21 percentage points. The values are means. In conclusions, within minutes, both 30 and 60 degrees head-up tilting is poorly tolerated in anesthetized swine. Significant differences among individual animals exist.
- MeSH
- arteriae carotides patofyziologie MeSH
- arteriální tlak MeSH
- blízká infračervená spektroskopie MeSH
- časové faktory MeSH
- celková anestezie * MeSH
- hemodynamika * MeSH
- kyslík krev MeSH
- modely u zvířat MeSH
- ortostatická intolerance krev patofyziologie MeSH
- oxymetrie metody MeSH
- postura těla * MeSH
- prasata MeSH
- regionální krevní průtok MeSH
- spotřeba kyslíku MeSH
- supinační poloha MeSH
- test na nakloněné rovině MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Early recognition of collapsing hemodynamics in pulmonary embolism is necessary to avoid cardiac arrest using aggressive medical therapy or mechanical cardiac support. The aim of the study was to identify the maximal acute hemodynamic compensatory steady state. Overall, 40 dynamic obstructions of pulmonary artery were performed and hemodynamic data were collected. Occlusion of only left or right pulmonary artery did not lead to the hemodynamic collapse. When gradually obstructing the bifurcation, the right ventricle end-diastolic area expanded proportionally to pulmonary artery mean pressure from 11.6 (10.1, 14.1) to 17.8 (16.1, 18.8) cm(2) (p<0.0001) and pulmonary artery mean pressure increased from 22 (20, 24) to 44 (41, 47) mmHg (p<0.0001) at the point of maximal hemodynamic compensatory steady state. Similarly, mean arterial pressure decreased from 96 (87, 101) to 60 (53, 78) mmHg (p<0.0001), central venous pressure increased from 4 (4, 5) to 7 (6, 8) mmHg (p<0.0001), heart rate increased from 92 (88, 97) to 147 (122, 165) /min (p<0.0001), continuous cardiac output dropped from 5.2 (4.7, 5.8) to 4.3 (3.7, 5.0) l/min (p=0.0023), modified shock index increased from 0.99 (0.81, 1.10) to 2.31 (1.99, 2.72), p<0.0001. In conclusion, instead of continuous cardiac output all of the analyzed parameters can sensitively determine the individual maximal compensatory response to obstructive shock. We assume their monitoring can be used to predict the critical phase of the hemodynamic status in routine practice.
- MeSH
- arteria pulmonalis patofyziologie MeSH
- krevní tlak MeSH
- lidé MeSH
- minutový srdeční výdej MeSH
- modely nemocí na zvířatech * MeSH
- plicní embolie komplikace patofyziologie MeSH
- plicní oběh * MeSH
- prasata MeSH
- rychlost toku krve MeSH
- šok etiologie patofyziologie MeSH
- srdeční frekvence MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
