Podcast Episodes

Ultrasound

Ultrasound is a vital tool for ECMO vascular access. Place the ultrasound machine on the opposite side of the patient from the operator. Make sure you are visualizing the vessel below the inguinal ligament and scan several centimeters of vessel to find the best place for puncture. Be familiar with transverse and in plane approaches. I am always surprised at the number of experienced practitioners who don’t move the probe to follow the needle tip during vascular access. Have a look the the video below for tips and tricks.

Needle & Wire

Scott Weingart has a nice video on central venous access microskills which are directly applicable to ECMO cannulation. Practice them until they are second nature.

Dilation & Cannula Placement

Confirming your wire with echo or fluroscopy is also a vital step as explained by Dr. Sascha Richardson at Reanimate conference here. After confirming your wire and making a stab skin incision with a scalpel the next step is serial dilation. Try to visualize the vessel pathway as you dilate. This means that the dilator should be as flat a possible with the tip directed slight medially. The wire should be moved within the dilator to ensure there are no kinks. It is vital that the assistant knows their role and how to manipulate . This ED ECMO episode gives some good tips. Importantly, when inserting the cannula the assistant needs to secure the obturator with their thumb while controlling the wire with the opposite hand. Once the cannula is in position the obturator is removed and the hub of the cannula is clamped.

Cannula Connection & Fixation

The cannulas are now ready to be connected to the ECMO circuit. This is a two person technique with the assistant dripping saline onto the connection and the cannulator slowly pushing the hub of the cannula into the ECMO tubing. Once attached the circuit is unclamped and ECMO flow begins.

There are many ways to secure the ECMO canulas. Many institutions suture the cannulas in place. This provides excellent stability but there is the a risk of bleeding or accidentally puncturing the ECMO line with the needle. Other institutions use tube fixation straps or devices such as the H-TAD. A newer approach using tissue adhesive has also been described in the literature. It is fast, safe and effective but has not yet seen widespread use.