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Successes of extracorporeal life support increased the use of centrifugal pumps. However, reports of hemolysis call for caution in using these pumps, especially in neonatology and in pediatric intensive care. Cavitation can be a cause of blood damage. The aim of our study was to obtain information about the cavitation conditions and to provide the safest operating range of centrifugal pumps. A series of tests were undertaken to determine the points at which pump performance decreases 3% and gas bubbles start to appear downstream of the pump. Two pumps were tested; pump R with a closed impeller and pump S with a semiopen impeller. The performance tests demonstrated that pump S has an optimal region narrower than pump R and it is shifted to the higher flows. When the pump performance started to decrease, the inlet pressure varies but close to −150 mmHg in the test with low gas content and higher than −100 mmHg in the tests with increased gas content. The same trend was observed at the points of development of massive gas emboli. Importantly, small packages of bubbles downstream of the pump were registered at relatively high inlet pressures. The gaseous cavitation in centrifugal pumps is a phenomenon that appears with decreasing inlet pump pressures. There are a few ways to increase inlet pump pressures: (1) positioning the pump as low as possible in relation to the patient; (2) selecting appropriate sized venous cannulas and their careful positioning; and (3) controlling patient’s volume status.

Objective: Usually only FDA-approved oxygenators are subject of studies by the international scientific community. The objective of this study is to evaluate two types of neonatal membrane oxygenators in terms of transmembrane pressure gradient, hemodynamic energy transmission and gaseous microemboli capture in simulated cardiopulmonary bypass systems. Methods: We investigated the Braile Infant 1500 (Braile Biomédica, São José do Rio Preto, Brazil), an oxygenator commonly used in Brazilian operating rooms, and compared it to the Dideco Kids D100 (Sorin Group, Arvada, CO, USA), that is an FDA-approved and widely used model in the USA. Cardiopulmonary bypass circuits were primed with lactated Ringer's solution and packed red blood cells (Hematocrit 40%). Trials were conducted at flow rates of 500 ml/min and 700 ml/min at 35ºC and 25ºC. Real-time pressure and flow data were recorded using a custom-based data acquisition system. For gaseous microemboli testing, 5cc of air were manually injected into the venous line. Gaseous microemboli were recorded using the Emboli Detection and Classification Quantifier. Results: Braile Infant 1500 had a lower pressure drop (P

Aim: Without volume-buffering capacity in extracorporeal life support (ELS) systems, hypovolemia can acutely reduce support flow. This study aims at evaluating efficacy and safety of strategies for preserving stable ELS during hypovolemia. Material & Methods: Flow and/or pressure-guided servo pump control, a reserve-driven control strategy and a volume buffer capacity (VBC) device were evaluated with respect to pump flow, venous line pressure and arterial gaseous microemboli (GME) during simulated normovolemia and hypovolemia. Results: Normovolemia resulted in a GME-free pump flow of 3.1±0.0 L/min and a venous line pressure of −10±1 mmHg. Hypovolemia without servo pump control resulted in a GME-loaded flow of 2.3±0.4 L/min with a venous line pressure of −114±52 mmHg. Servo control resulted in an unstable and GME-loaded flow of 1.5±1.2 L/min. With and without servo pump control, the VBC device stabilised flow (SD = 0.2 and 0.0 L/min, respectively) and venous line pressure (SD=51 and 4 mmHg, respectively) with near-absent GME activity. Reserve-driven pump control combined with a VBC device restored a near GME-free flow of 2.7±0.0 L/min with a venous line pressure of −9±0 mmHg. Conclusion: In contrast to a reserve-driven pump control strategy combined with a VBC device, flow and pressure servo control for ELS show evident deficits in preserving stable and safe ELS flow during hypovolemia.

Use of ultrasound (US) when introducing central venous catheters (CVC) may improve success rates, reduce the number of needle punctures, and decrease complication rates, but has been hampered by supposed difficulty in learning how to perform the technique. This study describes the learning curve for US-guided jugular CVC placement after a training program. After an initial slide presentation and a video, intensivists who had not previously used US for CVC placement were evaluated qualitatively for US set up (score S1) and technical skills (score S2). Quantitative measures included durations of different components of the procedure (T 1, time from entry of the US into the patient’s room to sterile dressing of the intensivist; T 2, time needed for sterile drapes, venous line preparation, and sterile sheath placement; T 3, time from skin puncture to venous flashback; T 4, time from guide insertion to dressing; T tot, total duration of the procedure); number of skin punctures; and a difficulty score allocated by the intensivist. We performed 150 evaluations of 30 intensivists: 50 % had no prior experience of CVC placement and 50 % no prior US experience. Maximal S1 and S2 scores were obtained with the fourth and eighth placement procedures, respectively. T 1 and T 2 did not change with ongoing training (5 and 8 min, respectively), but T 3 and T 4 decreased, from 5 min (first procedure) to less than 1 min (seventh procedure), and from 10 min (first procedure) to 7 min (sixth procedure), respectively. T tot decreased from 34 to 21 min at the eighth procedure. The number of skin punctures and the difficulty score decreased rapidly with the number of evaluations. Our study demonstrates that skills in US-guided CVC placement can easily be acquired with training.

Thermodilution (TD) is a gold standard for cardiac output (CO) measurement in critically ill patients [1]. Although transpulmonary thermodiluation is less invasive than the Swan-Ganz catheter, it still requires an arterial and deep venous line. This study will compare intermittent bolus transpulmonary TDCO with continuous CO (CCO) obtained by pulse contour analysis (PiCCO2; Pulsion Medical Systems) and non-invasive CO (NexCO) measurement via finger cuff using Finapres technology (Nexfin BMEYE).