Technique Articles

Introducing the Loop for Circuit Access during Extracorporeal Membrane Oxygenation: Feasibility and Safety

^* Pediatric Perioperative Medicine and Intensive Care, ECMO Centre Karolinska, Karolinska University Hospital
^† Department of Physiology and Pharmacology, Karolinska Institutet, and
^‡ Department of Women’s and Children’s Health, Karolinska University Hospital, Stockholm, Sweden

Address correspondence to: Lars Mikael Broman, MD, PhD, ECMO Centre Karolinska, Karolinska University Hospital, Eugeniavägen 23, Stockholm 17176, Sweden. E-mail: lars.broman@sll.se

Received: 23 October 2018
Accepted: 9 May 2019

Abstract

In extracorporeal membrane oxygenation (ECMO), blood is drained from the patient, and pumped through a membrane oxygenator/lung (ML) for gas exchange and then back to the patient. For monitoring blood gases, samples may be sampled downstream from the ML. This exposes the patient for embolization risk (air/clot) when the stopcocks are flushed. For safe sampling procedures, the Loop was introduced. It is a constant low-flow arteriovenous shunt (AVS) used preferably in venoarterial ECMO. It is composed of three different length and diameter three-way stopcocks connected to the circuit just downstream the ML with its return upstream the pump. It offers safe arterial blood sampling and a simultaneous access point to the venous side of the circuit. Since its introduction, no patient complications have been reported to be accounted for by the Loop. The Loop is an AVS permitting a safe access point for post membrane blood sampling and for injections in the venous pre-pump limb. It has a low cost and is easy to install and maintain. It may be used in any ECMO configuration.