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Saturday, July 26, 2014

The American College of Physicians free CME on high value care--I'm impressed!

Today in my inbox I got a letter entitled "ACP addresses medical costs." The American College of Physicians has, indeed, started to address medical costs, but this letter announced something quite wonderful. It was a free link (for ACP members only, unfortunately) to an online course that addresses some of the most needlessly expensive care that internists order. Although the course is not required, completing it not only gives me continuing medical education hours but maintenance of certification (MOC) points to maintain my internal medicine board certification.

Five years ago when I started writing this blog I proposed that in order to reduce healthcare spending in America physicians should be made aware of the cost of everything they order or prescribe and that they should be required to complete continuing medical education on cost effective medical care. Nobody read my blog back then, but apparently other people must have figured this out on their own. Most people don't know that doctors are mostly unaware of medical costs. When patients see their bills they probably just make the assumption that we are greedy and inconsiderate rather than gravely misinformed. It looks like one of internal medicine's major organizations (the ACP) has decided to do something about this.

Using fictional cases, they present itemized bills from hospitals and clinics and imaging centers, pointing out how we could make changes that would save patients money and risk, and giving some pointers on how to do our job more effectively.  There was a testimonial about how medical bills affect a young, uninsured person's life, which was entertaining because he was actually a comedian and the testimonial was part of his standup routine. His ruptured appendix cost $45,000. Ouch! The cases are followed by multiple choice questions. Did you know that 60% of all bankruptcy cases were due to medical bills? I chose 20%. That sounded bad enough. The right answer was 60%. Actually 62%, according to the discussion. Nearly 80% of those people had health insurance, so regardless of the effectiveness of the Affordable Care Act in reducing the number of uninsured, patients will still be hurting financially unless we change the way we practice. Other modules included data on how excess ordering of tests doesn't reduce malpractice suits and how to deal with patients' expectations for antibiotics for colds and MRI's for back pain. There were links to resources on medication costs and examples of the use of various risk calculators to help determine the best approach to common and alarming symptoms. Most of the information was not new to me, but enough of it was that the process was definitely worthwhile.

I just completed the 5 section module, which was interesting and probably mostly true. I learned all sorts of things, and if the majority of internists did the modules, I think there would be some noticeable behavior change, with corresponding humongous cost savings and improvement in care. I earned 13 maintenance of certification points for my internal medicine board certification, including the "patient safety" requirement which I didn't know existed, but clearly should exist. I don't think I actually need the points since I just completed my board recertification last year, but it never hurts to have extra education.

It is my firm belief that physicians, when given adequate information about what things cost and how to use medications, testing and procedures more appropriately will make changes in healthcare costs that will dwarf any savings related to high profile strategies like fraud prevention and cuts in physician reimbursement. The culture of medical care in the United States has been so far removed from considering costs that it will take some major shifts in the way we think for us to be good stewards of limited healthcare resources. I'm glad the ACP is taking on issues of cost transparency and evidence based diagnosis and treatment and that they have produced such an interesting and painless education product to push that agenda.

Tanzania, part 2

Being a doctor is an adventure, or so I thought when I started medical school. It has, in fact, never been boring and has often been exhilarating. But 25 years ago what I longed to do was to go to exotic places where everything was different than it is at home and where I could be really useful. After raising 2 children and doing primary care for about 2 decades, I've finally found enough spare time to go to Africa and it has been pretty great.

I just returned from Tanzania about 2 weeks ago after accompanying 11 University of California at Irvine medical students on a project to teach basic ultrasound skills to physicians and clinical officer students in Mwanza, a major city which sits on the shores of Lake Victoria. Using ultrasound at the bedside by a non-radiologist caregiver is gaining acceptance in the US, but still runs into resistance because of issues of competence and training and billing and turf. In Africa, though, you will find good consensus that it is life saving. The students have designed a curriculum that teaches how to use an ultrasound machine, how to recognize anatomy and obtain adequate images, and then additional training for second year students in identifying common pathology. The African students have excellent book understanding of anatomy, but don't have the opportunity to use cadavers for dissection so lack the 3 dimensional understanding that US medical students get. Ultrasound is a wonderful way to appreciate how the body works, and sets the students up to be able to become more skilled in using ultrasound diagnostically. Being able to see if a pregnant woman has a baby with a normal heart rate, identifying the position of the baby near delivery and seeing the placenta is potentially life saving for both baby and mom. Ultrasound can identify bleeding in the lungs or abdomen in patients who have been involved in motor vehicle accidents, extremely common in Tanzania, and a quick exam that can be performed competently by a medical provider with a few hours of training can lead to emergency surgery in time to save someone involved in a collision. It is simple to identify a pneumothorax (punctured lung) with ultrasound and that exam can save someone who has been stabbed or shot or whose broken rib pierced the lung. In the last 2 years, the students have taught basic ultrasound to about 180 doctors and clinical officer students. It is unclear exactly what impact that will have long term, but it is certainly a project that has the potential to keep on giving.

The American students involved in the project had completed their first or second year in medical school in an institution that teaches bedside ultrasound as an integral part of anatomy, physiology and pathology. After their first year they are quite good at performing basic ultrasound, and after teaching it in Tanzania and developing lesson plans, recording podcasts, creating and grading exams and practicing on each other so as to be able to teach, they are stars. My job was to review their material for accuracy and clinical relevance and answer clinical questions as they arose. We also attended rounds at the district hospitals as much as possible and sometimes contributed to diagnosis and treatment of patients. It was great to be able to work with Tanzanian physicians and the bright and well prepared clinical officer students. Having the small, portable ultrasound at the bedside allowed us all to look at what was going on in the patients, which helped us cross cultural and language barriers to really understand what was going on.

This year's project was, in fact, crazily complex. Surprisingly enough, and thanks to tireless and skilled organizational efforts by all of the students, it all came off. There was the basic ultrasound first year class. There was the second year introduction to ultrasound pathology class that had to be given at four different district hospitals where the second year clinical officer students were doing rotations. There were hospital rounds, which happened at various hospitals. And there was the schistosomiasis project. I wrote this about it before we really got into the gathering of data. The towns and islands on Lake Victoria have a really high incidence of Schistosoma mansoni and haematobium. The parasitic disease schistosomiasis is caused by a fluke that lives in the lake, harbored by snails and infecting swimmers and workers and fishermen and women as it burrows through the skin and takes up residence in the blood stream. The eggs of the fluke are very irritating and cause damage to the intestines, liver, kidneys and bladder in some people. We visited Ukerewe Island where it is said that about 100% of the population is infected with schistosomiasis. Many receive free treatment through schools, but although this program is supposedly available to everyone, quite a few children and most adults do not get the drug. Praziquantel, a big white pill, can be dosed once according to weight. It has occasional side effects of nausea or fatigue, but will kill the parasite and may reverse the symptoms which can include bladder dysfunction, cancer and kidney failure as well as liver dysfunction and liver tumors. Patients with schistosomiasis can also be anemic due to blood loss from ulcers in the intestines and have bowel troubles. We conducted ultrasounds of the liver, kidneys and bladder of all kinds of people and the lab checked their stool and urine for schisto eggs. Very few of the patients we saw were desperately ill, but a surprising number had intestinal distress and bladder abnormalities. In a place where people live, basically pretty healthily, with schistosomiasis, it appears that ultrasound may be able to help us identify which patients are developing problems which may cause longterm damage. If that is true, ultrasound might be able to help focus therapy on those people who really need it, since treatment of the whole population appears to be impractical.

It's so good to be back. I met wonderful people, saw birds of incredible variety, ate good food (especially the deep fried rice blobs--those were great), saw diseases I never see here, learned a little swahili, visited tropical islands, slept in Dubai, got uncomfortably close to a hippopotamus, didn't get dysentery. I observed medical students being awesome and encouraged their awesomeness. I learned a little bit of how a country with far too few physicians does a reasonable job of taking care of patients while using minimal resources. Now I can drink the tap water, walk on my familiar mountain, pet my dog who is not infested with parasites and sleep in my own bed. I can even speak the language fluently. It is wonderful to go adventuring, but possibly even more wonderful to come home.

Thursday, July 24, 2014

Bad breath and oral health--what's new and what's old?

Probiotics for the gut are very popular right now, and well so, since overuse of antibiotics has radically changed  the scope of intestinal illness in the US. When we take good effective antibiotics they kill not only the intended bacteria causing infection in our sinuses or lungs or bladders or skin but also quite a few of the innocent bystanders elsewhere in the body. Usually we manage to recover from the damage done, but sometimes we get life threatening overgrowth of bacteria or fungus which can have long lasting ill effects. Replacing bacteria killed with supplements containing beneficial organisms can reduce the harm caused by antibiotics.

But that's not what I'm talking about this time.

I noticed that some of the people who I love most have bad breath. Sometimes, I've heard, even I have bad breath.  Occasionally, despite having awesome oral hygiene, my mouth tastes kind of skanky and I could definitely believe that it wouldn't be pleasant to be in intimate conversation with me. So what is in my mouth that is nasty? Definitely not rotting food, because that is gone after I brush my teeth and has no way of magically reappearing. The taste, and smell, is worst after sleeping, during which time salivation is minimal and the natural washing action of the tongue is almost non-existent. Some people believe that nasty breath smells come from the sinuses or the stomach, but my knowledge of the plumbing of these areas suggests that I need look no further than the actual oral cavity. Genetic methods have identified over 600 species of bacteria in the mouth, most of which have not been well characterized. Some species lead to dental caries, others produce chemicals such as hydrogen sulfide or methyl mercaptan which smell nasty, while others modulate the oral environment to produce a healthy and disease resistant mouth. Dentists have identified Streptococcus mutans and Streptococcus sobrinus as being strongly associated with caries, but other patients with rampant caries did not harbor those bacteria and instead had multiple other identifiable bacterial types which may have been causal in their oral ill health. Still other bacteria may produce nasty smells but have no particular association with tooth or mouth problems. Some bacteria cleave sugars attached to proteins making it possible for other bacteria to digest those proteins, and thus produce smelly chemicals.

The human microbiome project was launched in 2008 to identify the bacteria which colonize us, including those of the mouth, gut, skin, vagina, lung and sinuses. This may well contribute to more effective therapeutics for the chronic diseases of these organs which are at present poorly treated by the heavy hitting pharmacological agents we are so good at developing. Antibiotics, so important in treating serious infection, can also kill bacteria indiscriminately leading to the growth of resistant organisms. They can also cause side effects on the kidneys, liver and bone marrow as well as serious allergic reactions. Immune modulating medications reduce our resistance to infection and cost ridiculous amounts of money. All of these are used to treat conditions of organs which have rich bacterial communities, without addressing the issue of what makes those communities healthy. Characterizing the flora of the mouth in health and disease could lead to novel therapies that might reduce gum disease and cavities as well as preventing things like strep throat and canker sores. Also bad breath.

Fecal transplant, that is introducing the bowel contents of a healthy person into a person with intestinal disease (limited right now to treatment of chronic Clostridium difficile infection) has proven to be powerful, simple and curative for people with bacterial diarrhea in whom antibiotics fail.There is increased interest now in all kinds of natural probiotics, helpful bacteria that are in foods, for overall gut health, with the hope of curing non-specific gut discomfort as well as intolerance of various food substances such as gluten and lactose. Might there be a precedent for oral bacterial transplants? Fecal transplant is abhorrent enough to humans that we have not come close to exploring its potential applications, and I can find nowhere on the internet describing a similar process for the mouth. Why would it not be useful to take oral bacteria from a person with excellent oral health and swab it into the mouth of someone who gets cavities at the drop of a hat or someone with rotten fish breath?

Presently I can't bring myself to request a sample of mouth bacteria from a friend with awesome oral health. It sounds like a great idea, but I am not adequately motivated and also am not sure I would actually trade up. I have very few cavities and never have mouth or throat infections, so maybe the bacterial community in my mouth, despite not always smelling sweet, is doing a fine job. Still, I haven't been able to resist trying a few of the easily available treatments that I have read about for sweetening the breath. Oral health experts recommend brushing the back of the tongue, where the tastebuds grow high and the bacteria tend to congregate. After brushing and gagging, my mouth does taste better for awhile. I have used mouthwashes a bit, but probably will not do so again after thinking about the implications of carpet-bombing my oral flora with chlorhexidine and alcohol. There is absolutely no reason to believe that the random bacteria which grow up after I use chlorhexidine will be any more beneficial than the ones I have now. I have bought oral probiotics which are chewed or dissolved in the mouth and contain beneficial strep strains, such as Streptococcus salivarius, which are purported to outcompete more harmful strep species. They taste nice, but I have not been impressed with any change in what I perceive as my mouth's health. Perhaps I chose the wrong brand. I have been most impressed with an ancient remedy, recommended by Hippocrates and Galen for diverse ills and prized by sultans' wives for sweetening the breath. Mastic gum, from the Pistacia lentiscus tree in Greece, is harvested by allowing the sap to leak from the tree and dry to hard chunks on the ground. When chewed, it tastes a bit like cedar and softens into a substance much like chewing gum. I bought some on Amazon, and it arrived from Greece a couple of weeks ago. I think I like it. It makes the bacterial soft plaque that I notice on my teeth go away and my mouth tastes fresh. My teeth feel like they do after a dental cleaning, more smooth and shiny than they do normally, and the effect lasts for a day at least. A study from 2002 shows an antibacterial affect against Strep mutans. I don't swallow it, but a study over a decade ago showed it to be effective against Helicobacter pylori in the stomach which can cause ulcers and stomach cancer. It's not clear that even mastic gum is benign to the good oral bacteria, but it has sure been delightful to have shiny teeth!

It will be good to see what comes of the Human Biome Project. It has such wide ranging implications for understanding the human body in health and disease. Treatments like mastic gum or dietary probiotics and even ideas like oral bacterial transplant are exciting for treatment of annoying and socially very significant conditions such as tooth decay and bad breath. They unfortunately do not have the driving force of pharmaceutical companies behind their development. Treatments that can be inexpensive and in the control of people who are not in healthcare professions have the potential to make powerful changes without associated costs. The paucity of research into this sort of thing can be traced to the fact that we do not have a very good mechanism for scientifically exploring therapies that don't make anybody money.

Wednesday, July 23, 2014

The debate rages (still): who should take cholesterol lowering drugs and why is the CTT bullying statin skeptics?

This morning I received an invitation to sign a letter authored by the Lown Institute in support of an article published in the BMJ (formerly the British Medical Journal) questioning the wisdom of prescribing statin drugs to patients at low risk of cardiovascular disease such as heart attack or stroke. "Statins" such as lipitor (atorvastatin) and zocor (simvastatin) are drugs which reduce cholesterol levels by inhibiting an enzyme on cell membranes. The article concludes that statin drugs are unlikely to be helpful to patients whose risk of heart disease or stroke is calculated to be less than 20% in 10 years. It was written by Dr. John Abramson, a lecturer at Harvard Medical School and the author of two books about inappropriate use of medications and tests, Harriet Rosenberg, a social scientist from Canada who has written about the lack of good scientific study of statins in women, Nicholas Jewell, a statistician from UC Berkeley and Dr. James M. Wright, a professor at University of British Columbia who writes about appropriate use of prescription drugs for a publication called the Therapeutics Initiative. It is excellent, concise and well written, so please consider following the link above to read it.

The Work of the CTT
One year before this article came out a group of lipid researchers called the CTT (Cholesterol Treatment Trialists) published a meta-analysis of 27 trials on the effectiveness of lipid lowering drugs and concluded that even very low risk patients (essentially everyone over the age of 50 with a few exceptions) could benefit from taking statin drugs, and that evidence showed that statin drugs cause minimal harm. Dr. Abramson et al combed through these same studies and concluded that the harms associated with statin side effects had been grossly underestimated and that actual mortality was not improved in low risk patients when they took statin drugs. Members of the CTT pointed out that Dr. Abramson and his coauthors may have misrepresented another study in describing the magnitude of statin side effects, so the article was changed to reflect this. Now the head of the CTT, Dr. Rory Collins of University of Oxford in the UK, is asking the BMJ to entirely retract the article, arguing that it misrepresents other information, it is unclear which, and might convince people who take statins to discontinue them. It appears, from the meta-analysis, that at least 140 people at low risk need to take statins for 5 years to prevent one major cardiovascular event (stroke or heart attack) and that there is no reduction in mortality at all for this group. It is also true that the vast majority of patients prescribed statins stop taking them within 2 years without any knowledge of this debate or even realization that there is a debate. Bloomberg Business Week comments on the conflict here.

Roots of the Disagreement
So it appears to me that some very intelligent doctors completely disagree on the subject of whether low risk patients ought to take statin medications. It comes down to differing values, I think. The doctors who favor giving statins to just about everybody over the age of 50 believe that it is no big thing at all to take a powerful medication daily so long as the side effects aren't horrendous or the cost individually prohibitive. Avoiding one stroke or heart attack in 1 of 140 patients is worth having the rest take a medication which doesn't clearly benefit them. The doctors questioning expanding statin use put a higher value on saving the 140 patients not destined for strokes or heart attacks from taking a useless medication with some obvious, though not universal, side effects.

Side Effects
And what about these side effects? What are they and why is there such disagreement about how significant they are? The most common statin side effect is muscle pain. In early drug trials the first statin, or HMG CoA reductase inhibitor, was so toxic to muscles that it resulted in the deaths of some laboratory dogs on whom it was tested. Subsequent statins were less toxic and rarely cause serious muscle breakdown, though muscle pain and spasms are common. Many patients discontinue the medication due to this side effect, but may tolerate another drug in a similar class or the same drug if it is tried again. This is often cited as evidence that the muscle pain was never the fault of the statin in the first place, though it is just as likely that patients, on finding their doctors insist that they take the drug that caused muscle pain simply quit talking about it and took the prescribed medication. Also common are complaints of weakness, foggy thinking and indigestion. More serious side effects include diabetes, which occurs more often in statin users (1 in 100 over 2 years) and severe and life threatening muscle breakdown. My personal experience of statin side effects when I practiced primary care medicine included professors who stopped taking statins because they couldn't think straight, middle aged hikers who discontinued statins because of progressive muscle pains, weakness and intolerable night spasms, an ancient man who had thought he was going to die because his back had become weak and painful while taking a statin, and thanked me profusely for years after for curing him by stopping his statin, and a woman who nearly died from statin induced rhabdomyolysis (sudden muscle breakdown) due to a drug interaction between her statin and another medication. I probably saw my share of statin induced diabetes, but was never on the lookout for it since that association was not known at the time. Many of my patients refused to ever take statins again due to muscle pain though they had been prescribed for perfectly good indications including after heart attacks or stent placements. For some patients there were no side effects of taking statins, but a sizable minority found these drugs very hard or impossible to tolerate.

Who are the CTT?
... and why do they think that these side effects are unimportant? According to the 2012 article, they are about 100 researchers who wrote diverse research papers about how effective statins were in reducing cardiovascular disease, most of which were supported by the pharmaceutical companies which produce statins. Many are academic cardiologists, and probably none are primary care physicians. They are mostly not in a position to actually prescribe these medications to real people and then see those people back on a frequent basis as they complain that they just don't feel as well as they did before starting the statin. They are also heavily cognitively invested in the truth of the research they have been involved in, which was designed, with drug company support, to be most likely to show that statins improve health and have minimal side effects.

Primary vs Secondary Prevention
It is well established that statins help reduce recurrent heart attacks in patients who have known coronary artery disease. This appears to be due to these drugs' ability to reduce inflammation which is an important cause of arterial narrowing. This use of statins is called "secondary prevention" and is pretty well accepted as a good reason to take them. There is solid agreement among mainstream physicians that use of statins in secondary prevention is usually a good idea. Treating patients who have not had an event such as a heart attack is called "primary prevention" and potentially involves billions of people who are otherwise healthy in medication treatment. Primary prevention with statins for high risk patients, say diabetic, obese and sedentary smokers with high cholesterol levels, is probably a good idea and is not part of the present debate.

The Successful Industry of Healthcare
Dr. Abramson et al make an excellent point at the end of their article that because the pharmaceutical industry funds so much of cardiovascular research most of this research is limited to drugs, creating a body of scientific evidence that drugs are the only route to good health. Less exhaustive but high quality research shows that lifestyle modifications, including a diet rich in fruits, vegetables and whole grains, exercise and avoidance of smoking, is very powerful in preventing cardiovascular disease and extending healthy life. If these things made any entity good money, we would be seeing a myriad of strategies to get patients to adopt healthy lifestyles. Instead, poor health and dependence on medications fuels an economically successful healthcare industry. Medicine as an industry thrives when people live longer but require many medications and many medical interventions, so expanded use of statins with associated significant side effects is a winning combination.

Drugs and Money
Statin drugs were responsible for over $29 billion in sales last year. This was a reduction of 11% from the previous year, because many of the statins have become generic. Increasing the number of prescriptions for these drugs will increase the revenue related to them and will fuel demand for newer drugs in the class or related classes. Although physicians in the CTT may only have patients' best interests in mind, drug companies sell statins in order to make money. The power of the pharmaceutical companies is likely an important factor in calls for retraction of article by Dr. Abramson et al which questions the present recommendations to expand indications for statin therapy.

Friday, June 27, 2014

Schistosomiasis in Tanzania--a prologue

I am in the African Republic of Tanzania. This year I have again accompanied a group of medical students from University of California at Irvine who will be teaching bedside ultrasound to clinical officer students at a medical school in Mwanza, the second largest city in this East African country. We will also be looking at the utility of ultrasound in diagnosing schistosomiasis, a parasitic disease which is endemic here.

Mwanza is on the coast of Lake Victoria, a huge body of water also bordered by Kenya and Uganda. Much of the commerce here has to do with the lake, both relating to tourism and fishing. Schistosomiasis is a water borne disease caused by a fluke that lives in the lake, harbored by snails. The snails are infected by the schistosomiasis miracidia and shed cercaria capable of infecting humans into the beautiful blue water where they penetrate the skin of mammals that swim in the lake. The flukes move through the lymphatic system, penetrate the blood vessels of the lungs and end up in the left heart and thence the blood vessels. They attach themselves to our blood vessel walls, nourish themselves on our blood, copulate constantly and produce eggs which are intensely irritating to our various internal organs. We eliminate eggs in our urine and bowels which go back into the water system to mature and complete the cycle.

Infection with Schistosoma mansoni and S. haematobium which are the predominant species here in Tanzania can cause fibrosis of the portal veins of the liver with chronic liver disease, scarring of the intestines and bladder with resulting kidney failure, malnutrition and anemia and chronic ulcerations of the lower genital tract. Less common and even more nightmare inspiring complications, including spinal cord and brain infection also occur. Most people in this community are infected, though only a relatively small proportion have noticeable symptoms. The most heavily exposed people are the most severely infected, including fishermen and car washers, but also include school aged children who are weakened and perform more poorly at school. Women with schistosomiasis genital lesions may be at higher risk for contracting HIV. Patients with associated bladder or liver disease are at higher risk of developing cancer of those organs.

Schistosomiasis is one of the "neglected tropical diseases" which are neglected because they occur primarily in very poor areas and to very poor people. In the case of schistosomiasis, neglect is enhanced because it is debilitating and chronic but not usually fatal. Nutrition and genetics affect how sick a person gets after being infected. Tourists sometimes return with schistosomiasis, but rarely to any great harm. The treatment is simple, a big dose of an anti-parasitic medication called praziquantel given once. It will clear the fluke from the blood stream and the body can heal any damage that is not advanced enough to be irreversible. In many patients, though, treatment is delayed until long after the point of no return.

The best way to cure schistosomiasis is to completely prevent infection, and since contact with   water is life to many people who live on the shores of rivers or lakes, the solution involves getting rid of the fluke. Some countries, most notably Japan, have entirely eradicated the disease using various approaches. Ideas that can work include biological control of snails, introducing predators or competing snails or infecting bacteria. Poisoning them doesn't work very well because other mollusks and fish also die. The very successful fishing industry in Mwanza, based on introduced Nile Perch which have decimated the omnivorous cichlid species that ate, among other things, snails, has worsened the snail problem. Dams and irrigation projects move snails to previously unaffected areas increasing the numbers of people exposed to the disease. Reducing certain plant growth along shores of ditches can reduce snails. Infected humans continue the cycle of infection by soiling water sources with urine or feces, so places with active sanitation efforts can significantly reduce their schistosomiasis burden. Large health organizations have proposed blanket treatment of school aged children with praziquantel, potentially yearly in some high risk communities, to both control human disease and reduce the reservoirs that lead to reinfection. This will be hugely expensive, but is probably necessary as part of a larger prevention effort.

I am looking forward to spending some time with the students on a large island in Lake Victoria where, we are told, 100% of the population has schistosomiasis. I expect we will see a vast array of tropical birds and fish and wide expanses of beautiful water, meet new and interesting people and see all kinds of tragic and preventable pathology. I might even go swimming. More later!

Friday, June 6, 2014

They do make an ultrasound probe that plugs into a USB port!

"They should make an ultrasound probe that plugs into your laptop. It could just hook into a USB port."

Ultrasound technology has become progressively more accessible to doctors who aren't radiologists. During my training, some obstetricians imaged the bellies of their pregnant patients to quickly see how the baby was lying in the womb and assess its progress. Other than that, ultrasound resided in the realm of the radiologists, who lived in dark rooms and interpreted blurry pictures for the rest of us. Since ultrasound is not expensive and has many potential applications, far beyond just seeing fetuses, other specialties have adopted it and doctors in resource poor countries where there are no radiologists have come to rely on it for all sorts of information. Trauma surgeons and emergency physicians can use it to rule in or out life threatening conditions, and internal medicine physicians like me can improve on the accuracy of our physical exams and sometimes avoid the cost of more complex and dangerous imaging procedures. Ultrasound can be used to guide procedures, making them safer. The machines have become smaller and are even pocket sized. It's all so very exciting.

So why not an app for the iphone? Why not Google glasses with which one can see ultrasound images of the patient in front of me? Why not a wireless ultrasound transducer?

The possible avenues of progress in very portable ultrasound technology have been slow for various reasons. First, many people are happy with radiologists imaging the body and cardiologists imaging the heart using large and expensive machines. The system works. It doesn't require the rest of us to learn ultrasound and the pictures are good and the rather large charges benefit hospitals. Bedside ultrasonographers are looking for inexpensive machines and it is unclear how much the use of these will increase the revenue stream which drives much of what happens in research and development in medicine.

Having wandered through the healthcare device industry's displays at many ultrasound conferences and having surfed the internet I thought I knew what kind of technology was available for doing bedside ultrasound imaging. I had seen an ultrasound transducer that plugged into an iPhone made by a company called Mobisante, and had seen their iPad/transducer combo. The software was buggy and the pictures were not impressive and the whole package did not end up being handy or attractive. I bought the GE Vscan machine which is about the size of my hand, and like my hand, fits in my pocket. The pictures are good and it does most of what I want it to do. So when people asked about just buying a transducer for a laptop and plugging it in I told them that clearly that was a great idea but it didn't exist.

Except that I was wrong. The company Interson, out of the Bay Area in California, makes transducers for imaging blood vessels, deeper structures such as abdominal organs, and cavities such as the throat and vagina/uterus. I had the opportunity to try their abdominal probe in the last few weeks. It is definitely a clever and versatile device, despite several drawbacks.

The probe is called SeeMore, which will probably not help sell the product. It is about as heavy as a small hardback book and it is a little big to have comfortably in a pocket. It has an inescapable resemblance to a personal vibrator which will also not help sell it. It is actually the same transducer that Mobisante used in their iPhone device. On the very positive side, though, it gives really good pictures of the abdomen, uterus and bladder. Its resolution is good enough that it could be used to rule in or out a pneumothorax, which my Vscan is not quite up to. Its image acquisition is slow so when looking at the heart it is not possible to see the delicate movement of the heart walls or valves, though it is possible to see grossly abnormal cardiac function or pericardial effusion from an abdominal approach. It does not do color doppler, so it cannot give any indication of blood flow. It has its own software that loads quickly onto a laptop and it could be used with a tablet so long as it has a windows operating system. The USB attachment can go into a USB to mini-USB converter so the tablet doesn't even need to have a full size USB port. Once the software is loaded it has calculations that are user friendly and intuitive calipers for measurements plus all of the usual gain adjustments that a person might want. There is a button on the transducer that freezes and unfreezes the image. After images are stored they can be printed or transmitted easily as JPEGs. If I worked in a bush hospital somewhere and needed my ultrasound just to evaluate unborn babies or critically ill or traumatized patients, this transducer would be just the ticket. If I used a laptop as I went from room to room, as I did at my last job, I can imagine information from this device being integrated seamlessly into my documentation as I examined the patient. The transducer I tried does not visualize superficial structures, like blood vessels or bones or tendons, abscesses or thyroids, but Interson makes a linear transducer that does. Each transducer costs $4000 new, and the software, support and hefty plastic case with tiny tube of ultrasound gel are included. My Vscan cost over $8000 and the cheapest portable ultrasound machine that hospitals in the US buy costs over $40,000 new. (Veterinary ultrasound machines and ones that are used in developing countries can cost much less than this, even in the sub $1000 range for a used machine.) From where I stand this USB transducer is an affordable alternative for point of care ultrasound, though I do like a machine that gives better pictures of the heart.

What about the Google glasses thing? I think somebody has a patent for that, though it's not commercially available. What about the wireless transducer? Yes. It exists. It is not Bluetooth, a proprietary short distance wireless connection that uses ultra high frequency radio waves. It uses a different proprietary ultra wide band wireless connection which can handle more information. The one that I found is called the Freestyle, by Acuson, which is now owned by Siemens. It looks like a TV remote and I think it's just for superficial structures.

As there is demand, these machines will get lighter, cheaper, more versatile and attractive. The potential is awesome and I'm looking forward to trying out new toys that will allow me more capably to help my patients.

Saturday, May 24, 2014

Ezetimibe (Zetia): why are we still prescribing what appears to be a useless drug?

A health research company just released a list of the 100 top drugs in America according to sales. 29th on the list, with sales of over 1.8 billion, is the cholesterol lowering drug ezetimibe, brand name Zetia. This drug was released over 10 years ago because it worked really well in combination with statin drugs such as Zocor (simvastatin) to lower LDL cholesterol levels. It was released as a single agent and combined with simvastatin as Vytorin. The only problem was that in 2008 a study of the ezetimibe/simvastatin combination compared to simvastatin alone showed the combination did not improve measurements of arterial wall thickness which correlates with things like heart attacks and strokes. Although cholesterol levels were lower in the combination arm, simvastatin was just as effective in achieving the more meaningful outcome. Ezetimibe appeared to increase cancer risk in another study, evaluating patients with aortic stenosis. A study which compared adding niacin or ezetimibe to statin therapy in patients with coronary heart disease in 2009 showed that, even though ezetimibe was very effective in reducing LDL cholesterol levels, it also increased the thickness of the arterial walls when compared to niacin. Niacin wasn't nearly as good at reducing cholesterol levels as ezetimibe, but there were more cardiovascular deaths in the ezetimibe group.

This drug, whose only claim to fame is that it reduces a number on a chemistry panel, continues to be popular in both the US and Canada. An editorial in the Journal of the American Medical Association (JAMA) in 2014 wondered at the failure of very convincing evidence to make us stop prescribing it. The author concluded that it must be that the manufacturer (Merck) has been very effective at marketing ezetimibe and that patients' and doctors' fixation on reducing the cholesterol numbers has made it attractive in defiance of its lack of efficacy. Statin drugs, which also are not immune to controversy, may reduce the risk of heart attacks by reducing inflammation, not by reducing cholesterol levels per se. Since ezetimibe acts to reduce absorption of cholesterol from the gut, it may have no effect at all on inflammation or vascular health despite lowering cholesterol levels.

There are further studies still in the pipeline which may clarify the situation a bit more. It seems right now, though, that there is enough evidence that this is a bad drug for the Food and Drug Administration to rescind its approval. It would be nice to believe that physicians would take the initiative to change their prescribing habits, removing 1.8 billion dollars from our healthcare bill while reducing our patients' pill burden, but apparently we are not stepping up to the plate.