Sunday, November 13, 2011

An update on our clave issue...

I just want to say that I think determining the cause of our issue on a Sunday isn't something that I really thought possible. We now know almost certainly what the issue is, and technically it isn't the clave. The MicroCLAVE is functioning properly and I do not think there is necessarily a problem with the device.

To begin with, I sent an email to ICU Medical this morning. I stated the issue I was having and asked them to read the blog post from earlier today. I received a response this afternoon:


I am very concerned that you have had this experience with our product in your home. Your detailed information and video is quite helpful, as this type of event has occurred recently in other areas and I feel very confident that I do know the cause. The 'smoking gun' in your account is how you describe that when you disconnected everything, it all looked perfect. Followed with how you attempted to try six other MicroCLAVEs in sequence, all with the same result.

As I am unfortunately not in the office today, I will send you some internal investigations that we have conducted which duplicated this problem first thing tomorrow. As an immediate measure, if you change-out your TPN delivery set (the one that connects into the MicroCLAVE), and only tighten until a friction fit is felt, I believe the leaking will stop. The problem is most likely hairline fractures in the luer of the tubing set that are almost invisible to the naked eye. These fractures allow for fluid to escape within the MicroCLAVE housing and out the area that is clearly visible in your video.

I am truly sorry for your experience, and will have more information for you tomorrow.

Alison Burcar
Vice President of Product Development

So, the advice that was given regarding the hairline fractures wasn't quite it, but it did lead me to determining why we were experiencing the leaking, and only with the MicroCLAVES and not the other claves we were using. In order to explain, you have to know a little more about these devices.

The devices that we have not had any trouble with have all been positive displacement devices. (Posiflow, MaxPlus, Ultrasite, etc... are examples) The inside of these devices looks similar to this:

When a syringe or extension set is inserted into the clave, it pushes the plunger out of the way. The inner chamber fills with fluid and then moved into the line through the connection in the bottom.

The MicroCLAVE ( and other devices like it) uses a straight fluid path. There are several benefits to this delivery system compared to the first. The straight fluid path is, however, why we are experiencing a problem with just the MicroCLAVES and not the other devices we were using. In the straight fluid path the tip of the syringe or extension set, when inserted into the clave, pushes the septum (plunger) down and open. A seal is formed between the split septum and the syringe or extension set.

Where the problem lies is that if there is any irregularity in the tip of the syringe or extension set it can't seal properly with the split septum which can cause fluid to flow through the area of the clave that is outside of the fluid path (Indicated in red).

We use an extra extension on Sam's IV to give him more length. (Vygon Lectro Spiral). These are made out of a slightly softer material than a typical extension set or syringe. After opening several packages today it appears that there is frequently small irregularities in the tip of the extension sets which is what is causing the leaks. These flaws are so minor that I wouldn't have noticed them if I wasn't looking closely. I don't feel that this is a defect, but is most definitely the cause of our issues.

So it appears that really these two products should not be used together. Hopefully now we can convince our homecare company to go back to a positive displacement device or provide a shorter extension with less irregularity that we can use in between the Vygon tubing and the MicroCLAVE.

Thank You to Alison Burcar from ICU Medical for getting back to me on a Sunday. Hopefully my research today will help someone else who may be having a similar problem.

1 comment:

  1. See comment on previous post. [The vygon/microclave mismatch is not a new problem and has been known to our home care company for the last few years...]