The substantial increase in the number of patients receiving extracorporeal membrane oxygenation over the last decade has led to an evolution of indications and an expansion into wider patient groups. One of the unanticipated benefits of the increase in extracorporeal membrane oxygenation has been a change in the understanding of the natural history of many respiratory diseases. Development in technology and materials, reduced extracorporeal membrane oxygenation-specific complications, and improvement of critical care, in general, have facilitated longer extracorporeal membrane oxygenation runs, and the definition of prolonged extracorporeal membrane oxygenation was recently expanded to continuous support for more than 28 days. This survey aimed to describe European ECMO centers' perception and arbitrary definition of prolonged extracorporeal membrane oxygenation, patient management, and futility. Of 94 center responses, 37% regarded 14-21 days, 30% 21-28 days, and 28% >28 days as prolonged treatment. Bridge to recovery (64%) or to transplantation (20%) was the most common causes. Awake, and ambulation while on extracorporeal membrane oxygenation was reported from 34% of the centers. In case of perceived futility, decision to withdraw was taken in 65% of the centers in agreement between profession and family and in 30% by profession only. One-fourth of the centers did not discontinue support. Large differences prevail among European ECMO centers concerning local perception and patient management in prolonged extracorporeal membrane oxygenation.

• Klíčová slova
• Europe, extracorporeal membrane oxygenation, futility, long-term, prolonged,
• MeSH
• lidé MeSH
• mimotělní membránová oxygenace metody   MeSH
• průzkumy a dotazníky MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa MeSH

Adequate extracorporeal membrane oxygenation support in the adult requires cannulae permitting blood flows up to 6-8 L/minute. In accordance with Poiseuille's law, flow is proportional to the fourth power of cannula inner diameter and inversely proportional to its length. Poiseuille's law can be applied to obtain the pressure drop of an incompressible, Newtonian fluid (such as water) flowing in a cylindrical tube. However, as blood is a pseudoplastic non-Newtonian fluid, the validity of Poiseuille's law is questionable for prediction of cannula properties in clinical practice. Pressure-flow charts with non-Newtonian fluids, such as blood, are typically not provided by the manufacturers. A standardized laboratory test of return (arterial) cannulae for extracorporeal membrane oxygenation was performed. The aim was to determine pressure-flow data with human whole blood in addition to manufacturers' water tests to facilitate an appropriate choice of cannula for the desired flow range. In total, 14 cannulae from three manufacturers were tested. Data concerning design, characteristics, and performance were graphically presented for each tested cannula. Measured blood flows were in most cases 3-21% lower than those provided by manufacturers. This was most pronounced in the narrow cannulae (15-17 Fr) where the reduction ranged from 27% to 40% at low flows and 5-15% in the upper flow range. These differences were less apparent with increasing cannula diameter. There was a marked disparity between manufacturers. Based on the measured results, testing of cannulae including whole blood flows in a standardized bench test would be recommended.

• Klíčová slova
• arterial, blood, cannula, extracorporeal life support, extracorporeal membrane oxygenation, pressure flow, return, water,
• MeSH
• design vybavení přístrojové vybavení   MeSH
• hemodynamika fyziologie   MeSH
• kanyla * MeSH
• katetrizace metody   MeSH
• lidé MeSH
• mimotělní membránová oxygenace přístrojové vybavení   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The use of extracorporeal life support devices such as extracorporeal membrane oxygenation in adults requires cannulation of the patient's vessels with comparatively large diameter cannulae to allow circulation of large volumes of blood (>5 L/min). The cannula diameter and length are the major determinants for extracorporeal membrane oxygenation flow. Manufacturing companies present pressure-flow charts for the cannulae; however, these tests are performed with water. Aims of this study were 1. to investigate the specified pressure-flow charts obtained when using human blood as the circulating medium and 2. to support extracorporeal membrane oxygenation providers with pressure-flow data for correct choice of the cannula to reach an optimal flow with optimal hydrodynamic performance. Eighteen extracorporeal membrane oxygenation drainage cannulae, donated by the manufacturers (n = 6), were studied in a centrifugal pump driven mock loop. Pressure-flow properties and cannula features were described. The results showed that when blood with a hematocrit of 27% was used, the drainage pressure was consistently higher for a given flow (range 10%-350%) than when water was used (data from each respective manufacturer's product information). It is concluded that the information provided by manufacturers in line with regulatory guidelines does not correspond to clinical performance and therefore may not provide the best guidance for clinicians.

• Klíčová slova
• cannula, drainage, extracorporeal, extracorporeal membrane oxygenation, flow, life support, pressure, venous,
• MeSH
• design vybavení MeSH
• kanyla * MeSH
• katetrizace metody   MeSH
• lidé MeSH
• mimotělní membránová oxygenace přístrojové vybavení   MeSH
• vény MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH