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mixed up medical tubes and Murphy's Law

The New York Times reports on how mixing up medical tubes (IV tubes, gastric tubes, oxygen tubes, and so on) is injuring and killing patients:

Hospitalized patients often have an array of clear plastic tubing sticking out of their bodies to deliver or extract medicine, nutrition, fluids, gases or blood to veins, arteries, stomachs, skin, lungs or bladders.

Much of the tubing is interchangeable, and with nurses connecting and disconnecting dozens each day, mix-ups happen — sometimes with deadly consequences.

“Nurses should not have to work in an environment where it is even possible to make that kind of mistake,” said Nancy Pratt, a senior vice president at Sharp HealthCare in San Diego who is a vocal advocate for changing the system. “The nuclear power and airline industries would never tolerate a situation where a simple misconnection could lead to a death.”

Some manufacturers have started using color codes to distinguish tubes for different functions -- but they've each used their own scheme, thus adding to the confusion! In 2008 California passed legislation mandating that different sorts of medical tubes not be compatible with each other, but the manufacturers’ trade association managed to push back implementation to 2013 and 2014.

As for the FDA, decades of a conservative "free-market" approach have left it toothless; its device-approval process only requires that a manufacturer prove that their new product works just like an old one -- whether the old one is safe or not. According to Dr. Robert Smith, a former FDA device reviewer, "[The] FDA could fix this tubing problem tomorrow, but because the agency is so worried about making industry happy, people continue to die."

This sort of screw-up has resuted in hundreds of deaths and serious injuries. No one knows for sure how many, because these and other sorts of medical errors are rarely reported; but a 2006 survey found that 16 percent of hospitals had experienced a feeding tube mix-up.

Experts have been advocating since at least 1996 that medical tubes and devices for different functions shouldn't fit together. This is a basic principle in computer hardware design: if cable type X shouldn't be inserted into port Y, then it ought not to be possible to do so. That's why ethernet cables, USB cables, modem/phone cables, power cables, video cables, et cetera, are all different.

This is because hardware designers understand Murphy's Law. Properly, that Law states "If there are two or more ways to do something, and one of those ways can result in a catastrophe, then someone will do it." (The principle that "Anything that can go wrong, will go wrong" is a mis-quote of Murphy -- which perhaps demonstrates the law in action! -- and is more correctly known as "Finagle's Law".)

Ergo, whenever possible, there should not be an easy way to do something that will cause a catastrophe.

You can never completely prevent someone from causing a catastrophe, of course; I can always cut a power cord and stick the live end in a USB socket, and a nurse could always cut the ends off of two incompatible tubes and tape them together. And trying too hard to prevent catastrophes can also prevent very clever and helpful things. But when you're dealing with any safety-critical system, it should take a deliberate, conscious effort to override fail-safe design features.

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