Worldwide Shortage of Barium 270
New submitter redhat_redneck writes "The U.S. and Canada has been experiencing a shortage of barium sulfate, which is used as contrast for upper and lower GI studies. It has reached the point where doctors are being asked not to order these exams except in emergencies, and some exams are being cancelled. Here's the letter that's been put out by the manufacturer. The longer this drags on, the more serious this issue becomes, eventually impacting patients and healthcare providers in both cost and quality of care. Some sources point to a dramatic drop in Chinese production. In their defense, it seems China is changing safety regulations. Medical use only make a fraction of the uses of barium sulfate, but it's going to be disproportionately affected by this shortage. We can't go back to our old contrast Thorotrast; it causes cancer. Does anyone know of alternatives to barium?"
Re:What the what what? (Score:5, Informative)
Of course Slashdot readers are supposed to get it.
Contrast is what it says. It's there to make whatever you want investigate stand out from the rest observe it. For instance to make blood vessels easier to see. (Now I don't know whatever this is x-ray, MR, ultra-sound or whatever.) My english isn't good enough to know what GI is (gut-ingestion?) but I guess it's the stuff from the throat to the ass.
Re:What the what what? (Score:5, Informative)
what GI is (gut-ingestion?) but I guess it's the stuff from the throat to the ass.
Gastrointestinal, your guess is correct: mouth-esophagus-stomach-intestines-anus. It's basically one continuous external surface inside the body.
Re:Why do they not recycle? (Score:4, Informative)
the icky-factor is it, both aesthetically and practically. barium is excreted in the feces, not urine. so, you have the choice of doing it at the hospital, which will be inefficient (no economy of scale, and unspecialized labor), or you could do it in central locations, which would require the transport and processing of huge shipments of collected human fecal matter, the difficulties of which should be obvious. it's doable of course, but rather unlikely.
as a side note: several years ago when i went to the hospital at my college town, i noticed the vaulted ceilings and friezes put there to cater to the wealthier residents, and i recalled them quite vividly when i got my bill. i'd rather have modest (but sterile) facilities and pay less, but image is everything i suppose. the point is, not only is there "icky-factor," there's the implicit standard of living which we "must" maintain. asking patients to shit into a jar and bring it back to the hospital would just be unimaginable. for better or worse, quite a few people would literally rather die than shit into a jar for two days.
Re:What the what what? (Score:5, Informative)
Re:Locally produced Barium (Score:2, Informative)
Is there any other place to get Barium besides China?
They're called rare earth metals not so much because they're rare, since they're a bit all over the place, but because they're not concentrated enough to mine efficiently. This makes it highly polluting to extract them.
The US a couple more countries used to extract them, until China came along with no pollution standards, and priced everyone out of the market. Trouble is, you can't "just restart" such a mine. It's a decade long process to do so -- and it's in progress insofar as I've been following, because China decided to keep these strategic minerals for itself so as to keep high tech manufacturing at home.
Re:What the what what? (Score:5, Informative)
Barium is a rare earth metal.
Not exactly, Barium is an alkaline earth metal, related to Magnesium and Calcium. Interestingly though, the U.S. are one of the largest producers of Barium, accounting for about 8% of the world wide barium output. It's mainly mined as barit, or heavy spar.
Re:What the what what? (Score:5, Informative)
Layman's explanation: Contrast agent is something that shows up as a bright color on your scan. There are many different kinds of contrast used for many different purposes, too many to list here. Barium contrast is swallowed and shows up as bright white on regular X-rays and CT scans (CTs are a multitude of X-rays taken by a computerized scanner which is then turned into a quasi-3D representation.) The reason somebody would use barium is to look at the shape of the esophagus (food pipe), stomach, intestines, and rectum to see if there are any parts that are too wide, too narrow/pinched off, the wrong shape, if there is a blockage, etc.
Not so layman's explanation of the tests mentioned:
- Barium swallow: Barium is swallowed and a real-time series of X-rays (fluoroscopy) of the throat (pharynx) is done to see if the barium is swallowed properly. The resulting video shows where the barium goes. This is ordered if the doctor suspects the person may be having problems swallowing (aspiration or refluxing.)
- Esophogram: Barium is swallowed and fluoroscopy of the esophagus is performed to see if there are any abnormalities of the size/shape/anatomy of the esophagus. This is also ordered if somebody has trouble swallowing and the doctor suspects some problem like a stricture, widening of the esophagus (achalasia), abnormal anatomy of the esophagus (such as a diverticulum, malignancy, etc.)
- UGI = Upper gastrointestinal study. This fluoroscopy stufy follows the barium from being swallowed until it goes into the stomach. It shows all of the same things as the esophagram along with the size/shape/anatomy of the stomach as well. Ordered for the same reasons as the esophagram as well as if you suspect some anatomic problem with the stomach (e.g. stomach stapling/bypass not working correctly, etc.)
- Small bowel follow through: Barium is swallowed and then a series of individual X-rays taken at certain time intervals to track the progress of the barium through the stomach and small intestine. This is done to investigate things like the stomach emptying too slowly and obstructions in the small intestine.
- Barium enema: Barium is given via enema into the rectum to look at the anatomy of the rectum. This can investigate anatomic abnormalities of the rectum such as masses and fistulas (a hole from the rectum to somewhere else, this is abnormal.) This can also be used to both diagnose and treat intusussception (a disease of infants where part of the large intestine telescopes into itself.)
Re:Alternatives include (Score:3, Informative)
Unless the patient is intolerant of iodine, which many people are. Granted, most are intolerant of *IV* iodinated contrast media rather than PO, but if they have "iodine in contrast" in their allergy list, what radiologist wants to risk getting sued for giving them Gastrografin? Not many I know of, for sure...
Re:Locally produced Barium (Score:3, Informative)
Ouch! Complete chemistry fail!
Barium is certainly NOT a rare earth. It is an alkaline earth metal. Look at the periodic table for christ's sake.
And the sad thing is this got modded up. Doesn't anybody know their high school chemistry anymore?
*weep*
Re:Alternatives include (Score:1, Informative)
Iodine compounds are less satisfactory than barium for gastrointestinal imaging.
Barium sulfate is used as an aqueous suspension with viscosity modifiers and coating agents. This causes it to stick and coat the internal surface of the organ being examined, as the particles are bound to the thickeners and thence to the organ surface.
Iodine contrast agents are low viscosity aqueius solutions which don't coat. Attempts to use coating agents has been unsatisfactory because iodine compounds are not sufficiently x-ray opaque to be visible as thin coatings. Instead the organ cavity must be completely filled with the solution.
a surface coating agent provides much better surface image detail, while iodine only provides a featureless silhouette of the Cross section of the organ cavity. This makes barium a much more useful agent in the gastrointestinal system. Iodine is only suitable where barium cannt be used AND where the information required does nit require the high resolution, high contrast images provided by barium. Barium could showa small tumour or polyp. Iodine would not. A huge tumour causing obstruction of tthe GI tract could not be safely Examined with barium because the barium would not clear and may form solid rock like aggregates prior to surgery where it would pose additional risk. Iodine would be adequate in this scenario as yiu don't need high rezolution to see that a cavity doesn't fill up and as the iodine compound is water soluble, it doesn't interfere with surgery.
Re:What the what what? (Score:5, Informative)
Typical impurities in US barium sulfate (Nevada mines) are silica and strontium sulfate. Silica can be somewhat removed via froth flotation using standard commercially known techniques. The Sr is bound up in the Ba-Sr-SO4 lattice and very difficult to remove. Were they not bound together in the crystalline structure you could likely use an alkaline leach with sodium hydroxide (I saw a patent from the 1930s or 1940s that discussed this very approach), but when they are bound together you do not get selective leaching. Also, because they are bound together gravimetric separation (SrSO4 = ~3.8 SG IIRC, BaSO4 = ~4.45 SG) doesn't work.
Sr and Ba are very similar chemically, but to meet the USP requirement of 97.5% min BaSO4 you have to be able to get the purity up (or start with a high purity ore). The USP assay test differentiates between the two because of the difference in solubility as chromates - the Sr chromate is much more soluble but you have to convert everything to chromates to get the Sr to drop out, then you'd have to convert the Ba chromate back to BaSO4 and not leave any chromate in there, as it is very toxic. At that point you are no longer dealing with natural purified barium sulfate but are instead making a precipitated barium sulfate, in which case you could just start with pretty much any barium compound and fully react it with sulfuric acid. The problem here is that any soluble barium left behind is very toxic (for a real life example of what could go wrong see http://en.wikipedia.org/wiki/Celobar_incident).
By the time you do all of the processing above the cost is nowhere near what could be achieved with natural, high-purity barium sulfate ore that undergoes a simple acid leach.