Pressure and flow properties of dual-lumen cannulae for extracorporeal membrane oxygenation

Abstract

Introduction: In the last decade, dual-lumen cannulae have been increasingly applied in patients undergoing extracorporeal life support. Well-performing vascular access is crucial for efficient extracorporeal membrane oxygenation support; thus, guidance for proper cannulae size is required. Pressure–flow charts provided by manufacturers are often based on tests performed using water, rarely blood. However, blood is a shear-thinning and viscoelastic fluid characterized by different flow properties than water. Methods: We performed a study evaluating pressure–flow curves during standardized conditions using human whole blood in two commonly available dual-lumen cannulae used in neonates, pediatric, and adult patients. Results were merged and compared with the manufacturer’s corresponding curves obtained from the public domain. Results: The results showed that using blood as compared with water predominantly influenced drainage flow. A 10-80% higher pressure-drop was needed to obtain same drainage flow (hematocrit of 26%) compared with manufacturer’s water charts in 13-31 Fr bi-caval dual-lumen cannulae. The same net difference was found in cavo-atrial cannulae (16-32 Fr), where a lower drainage pressure was required (Hct of 26%) compared with the manufacturer’s test using blood with an Hct of 33%. Return pressure–flow data were similar, independent whether pumping blood or water, to the data reported by manufacturers. Conclusion: Non-standardized testing of pressure–flow properties of extracorporeal membrane oxygenation dual-lumen cannulae prevents an adequate prediction of pressure–flow results when these cannulae are used in patients. Properties of dual-lumen cannulae may vary between sizes within same cannula family, in particular concerning the drainage flow.

Dynamic extracorporeal life support: A novel management modality in temporary cardio‐circulatory assistance

“…Special considerations are needed for the drainage and/or perfusion conditions, which are highly dependent on the interaction of flows and resistances in the respective circuit limb. 11,[26][27][28] The PA cannula, if used as an adjunctive drainage point, is usually connected to the larger main draining cannula (often in right atrium cannula from the femoral vein). Drainage from the PA cannula may, therefore, be influenced and limited by the drainage flow from the right atrium, with potential reduced drainage, stasis and ultimately thrombosis of the cannula placed in PA. To overcome or enhance an optimal flow (1.8-2 L/min) from the PA cannula and to avoid the risk of cannula clotting, the cannula flow from the right atrium needs to be regulated allowing minimal drainage from the PA itself avowing the abovementioned shortcomings.…”

“…Special considerations are needed for the drainage and/or perfusion conditions, which are highly dependent on the interaction of flows and resistances in the respective circuit limb 11,26‐28 . The PA cannula, if used as an adjunctive drainage point, is usually connected to the larger main draining cannula (often in right atrium cannula from the femoral vein).…”

Pressure and flow properties of dual-lumen cannulae for extracorporeal membrane oxygenation

“…of venous tubing) for evaluating neonatal and pediatric cannulae, which is the major limitation in their study. 1 Using adult circuitry for neonatal and pediatric cannulae evaluation results in significantly lower extracorporeal circuit pressures that may lead to substantially lower pressure drops of the entire circuit components. Despite this major design limitation, the results of this investigation may give the clinicians more scientific evidence for cannulae selection if one compares two cannulae directly.…”

“…To improve the extracorporeal life support (ECLS) patients' outcomes, translational research is a necessity, not an option. [1][2][3][4][5][6] The French size refers to the outer diameter of all extracorporeal cannulae. In addition to the cannula size, cannula length and wall-thickness have a direct impact on pressure drops.…”

“…Dr Broman and his fellow colleagues intended to standardize pressure-flow charts of two dual-lumen cannulae (OriGen and Avalon ELITE) configurations used in neonatal, pediatric, and adult patients in their article. 1 The authors compared their results with each manufacturer’s pressure-flow curves for each cannula’s brand separately rather than directly evaluating two cannulae together.…”