ABSTRACT
Setting the occlusion of a roller pump may be facilitated using the TRansonic HT109 Ultrasonic Flowmeter (Transonic Systems, Inc. Ithaca, NY) with non-invasive transducer. The process addresses the need to set occlusion quickly and accurately before initiation of extracorporeal membrane oxygenation (ECMO). This can be performed with the circuit tubing before blood prime and does not require opening the fluid filled ECMO apparatus to air. The principle is based on the fact that fluid flow through the tubing will change with roller occlusion. Using the Transonic flowmeter, a pre determined (partially occlusive) setting can be achieved by first determining the point of total occlusion, then decreasing occlusion a small percentage from this maximum (i.e., total) occlusion. Clinical application in 35 neonatal ECMO cases has shown the practice to be safe, reliable, and efficient.
Subject(s)
Extracorporeal Membrane Oxygenation , Humans , Infant, Newborn , RheologyABSTRACT
A failure analysis was performed on Norton S-65-HL Tygon tubing. Fatigue testing was performed on four sizes of this tubing, and essentially showed how the tubing wears out. A dynamic "life hours to failure" test, which was performed on the 3/8" internal diameter (ID) size, quantified when the tubing ruptured. Based on results of laboratory testing and the institution's clinical extracorporeal membrane oxygenation (ECMO) experience, a reasonable life expectancy for the 3/8" S-65-HL Tygon size was determined for use in this institution's neonatal ECMO system. An understanding of the expected performance of roller pump tubing-an integral component of the ECMO system-is imperative to providing safe, effective extracorporeal life support.
Subject(s)
Extracorporeal Membrane Oxygenation/instrumentation , Intubation/instrumentation , Elasticity , Equipment Failure , Extracorporeal Circulation/instrumentation , Humans , Infant, Newborn , Intensive Care, Neonatal , Life Support Care/instrumentation , Materials Testing , Stress, Mechanical , Surface Properties , Tensile Strength , Time FactorsABSTRACT
ECMO, as applied to neonates with severe respiratory failure, involves either a single or dual cannula system for removal of desaturated blood from and return of oxygenated blood to the patient. ECMO cannulas have undergone considerable change and improvement since the early 1980s, and a variety of cannulas are now available commercially for neonatal ECMO. All ECMO cannulas have a characteristic appearance on the chest radiograph, which is important in the assessment of cannula position and some cannula complications. We report the physical characteristics, advantages, disadvantages, and radiographic appearance of the most widely utilized neonatal ECMO cannulas.