By guest blogger Michael Cohen:
Not too long ago I pulled into a gas station to fill up the tank. I got out of the car and realized that I was in front of a diesel fuel pump, not one for the gas. But even if I was in a distracted state of mind, I would not have been able to pump diesel into the tank, since the nozzle was purposely designed so it won’t fit my car’s tank. This same kind of “design for safety” thinking has not yet reached hospitals. If you accidentally attach a tube intended for one part of the body with another, you could harm or even kill someone. Until now, we’ve focused more upon expecting doctors and nurses to never make these mistakes rather than doing something more effective, making it impossible for them to do so.
A New York Times article by Gardner Harris recently brought this problem to light, although those of us in health care have known and complained about the problem for years. Harris described a case where a nurse accidentally coupled a liquid food bag meant for a tube in patient’s nose leading to her stomach, with one that entered a vein. Gardner correctly noted that “putting such food directly into the bloodstream is like pouring concrete down a drain.” It can make breathing difficult or impossible and can also cause infection. The patient in this case later died.
In health care, for over 100 years, most syringes, tubes and catheters have shared the same connection, a standard size tapered male fitting that matches with a female counterpart. It’s called a Luer connection after the man who developed it. A good example is a hypodermic syringe, the male end of which attaches to the female IV catheter that provides access to the blood stream. As of now, tubes and syringes exist for monitoring blood pressure, anchoring breathing tubes, giving fluids into veins, monitoring various pressures inside and outside the body, giving feedings or extracting fluids from the stomach, irrigating wounds on the skin, instilling or draining the bladder, and accessing the central nervous system. All of them share the same Luer connection. This was done so that in an emergency, the same syringe could be used to give drugs, sample body fluids, monitor pressures or pull out fluids. Otherwise you’d need to locate different ones for different purposes and that would cause delays.
Harris claimed that lax federal oversight of medical devices and an overly influential profit-motivated industry has thwarted safer designs that would prevent tubing mix-ups. He quoted one ex-FDA staffer as saying, “FDA could fix this problem tomorrow but because the agency is so worried about making industry happy, people continue to die.”
The issue of catheter mix-ups truly is a serious problem, but it goes far beyond those mentioned in the article. It’s not the sort of issue that you can just fix. There could be enormous unintended consequences unless this is done systematically, giving time for trial and error during simulations and later in clinical research. We also need to recognize that we would essentially need 7 different kinds of connectors to render syringes, catheters and tubing meant for one part of the body incompatible with one all others.
Imagine that you are a doctor taking care of an ER patient and you need a syringe to inflate a breathing tube balloon anchor (so the tube doesn’t come out) and all you have near by is one for IV use. The patient might die while someone ran around trying to find the right syringe. Inventories in supply departments, pharmacies and clinical areas would become a nightmare. One of my biggest fears is that there would still be room for someone to accidentally draw a medication from a drug vial using the wrong type of syringe, one that would only connect to the wrong catheter. This is one of the possible unintended consequences.
Until there is a recognized standard, industry is not going to be in a position to create new products, only to find that they are obsolete when a standard does get promulgated. This issue is very complex because there are many components in products, and no one company owns all the parts and pieces. For several years there were numerous inter-company product connection issues as not all were aligned with the Luer standard. We had catheter hubs fracturing; connections that would not disconnect, and even connections that failed to remain connected. It took a long time for everyone to correct dimensional issues and have a "plug and play" system that allowed an infinite number of possible connections to be safe and secure. No company wants to receive reports that their products were involved in a serious error from a misconnection, but at the same time I don't think any company is in a position to dictate a standard.
A group called AAMI (Association for Advancement of Medical Instrumentation) is actively working on this with the ISO (International Standards Organization). But it definitely is not a simple single connection issue. Importantly, articles like the one in NY Times do call attention to a very serious problem and one that we think does need correction. However, FDA, industry and other groups need to carefully develop these new standards. The last thing we need is a panic situation where not enough attention is paid to first rooting out unintended consequences.
I would much rather see a focus on one or two major areas that need fixing. One that I’d like to see addressed is connections to the spinal route. We’ve had many mix-ups with IV substances going into the spinal fluid, an error that can be fatal to cancer patients. There has already been some work done to make the spinal connector incompatible with the IV connector, especially in the UK where use of incompatible spinal devices is about to become a requirement. Also, our medication safety reporting program has seen numerous mix-ups over the years between feeding tubes (enteral) and vascular tubes (intravenous). That seems to be the most pressing problem of all. Some progress has already been made with special oral syringes and GI catheters that will not allow connections with IV equipment. These two areas alone would eliminate the vast majority of misconnections we’re familiar with.