diagnostic errors

Monday, May 18, 2015

It’s the spectacular play that makes the highlight package on Sportscenter. Fans can be amazed at the amazing catch or incredible shot. But at the end of the day, it’s mistakes that lose games and cost championships. Sometimes, it’s the referee or umpire who misses a call and is blamed for adversity. The solution often offered is technology with instant replay, slow motion and multiple camera angles to oversee what had been judged in the blink of an eye. Victors are those who avoid the most mistakes and take advantage of the errors of their opponents.

It is not widely publicized, but mistakes happen in medicine and at an alarming rate. There is a presumption, by patient and family, that technology decreases the risk of errors and makes for better care. That line of thinking opens a Pandora’s box of wrong. Some doctors feel obligated to order tests to confirm their clinical suspicions. Some suffer from a lack of confidence to stand by their bedside decisions. Others believe that ordering a test will decrease their perceived risk of being sued, the concept of “covering their butt”. And sometimes, tests are ordered because families want the reassurance of technology, since blood tests and x-rays can be tangible proof that all is well…except those tests are only as good as their interpretation, done by a radiologist or pathologist who is an anonymous, faceless provider. All the doctor or patient sees are the results on a computer screen. After all, if it’s in the computer, it must be true.

But mistakes happen and at a relatively high rate. X-ray results aren’t always perfect and different radiologists can interpret the same picture in different ways. When reviewing a radiologist’s reports, the error rate can range between 3 and 3.5%. More complicated studies like CT, MRI and ultrasound can have error rates as high as 7%. Interestingly, if one asks more than one radiologist to read a film, the resulting discrepancy rate can run higher than 30%, meaning they don’t agree with each other a third of the time. But that does not necessarily lead to patient harm, because any test result needs to be interpreted in the context of the bedside assessment of the patient.

The key begins with ordering the test in the first place. There needs to be an expectation that the extra information will be a decision maker for the doctor when it comes to diagnosis and treatment. There needs to be a plan of action for each positive or negative result. Blood tests can be very reassuring when they are normal, except when there are false positives and false negatives. The doctor needs to understand the limitations of each blood test and not be falsely reassured when a test comes back normal, only because it was drawn too early in the disease process…or too late. Imagine taking a pregnancy test immediately after intercourse, knowing that it is too early to turn positive, and yet relying on that result for the next none months.

No matter how much or how little technology is used, getting the right diagnosis is tough. Studies from Johns Hopkins estimate 80,000-180,000 patients in the US are harmed each year because of diagnostic errors. Most happen in the doctor’s office as opposed to the hospital and most are due to a missed diagnosis, rather than a delayed or wrong one. Which brings the discussion back to using technology as a crutch instead of a tool.

Diagnosis is based on history. The patient will tell the doctor what’s wrong if the doctor has time to listen, ask the right questions and interpret the answers. Patients and families are often frustrated when the same questions are repeatedly asked by the person who escorts them to the exam room, the nurse who takes their vital signs and the doctor who seems to be in too much of a hurry to really listen. Each listener can interpret an answer in a different way, and nuance can be helpful in pointing the doctor in the right direction to make a diagnosis. Physical exam is helpful but the guiding light tends to be the history, the old fashioned sitting down and talking to the patient. Diagnosis may be self evident but most often it takes time.

Errors will happen in sports and in the doctor’s office. Minimizing the number of errors should increase the chances of winning; the stakes are just a little higher for the patient. There is an art to diagnosis and technology offers few short cuts. For those who prefer computer algorithms in making a diagnosis, try asking a computer to assess the wife’s face that frowns when her husband minimizes a complaint with that recognition leading to a new line of questioning and perhaps the right answer. Nobody said anything about talking needing words.

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back pain

Tuesday, October 28, 2014

Fans always want to know the ins and outs of NFL injuries. Understanding what happens on the sidelines or in the locker room may help their fantasy football predictions or perhaps satisfy their prurient interest, like slowing down when driving by an accident, but it also engenders a false expectation of what the real world can bring to medical care. If technology was used on every person with a back injury like it was on the Cowboy’s Tony Romo, Medicare would be in a deeper financial hole than it already is.

Admittedly, even for an elite athlete, Mr. Romo’s case is special. Last year, he required surgery to repair a ruptured disc in his back and he has had to limit his practice time so that he could play on Sundays. Still, the Cowboy nation held its breath when he lay on the turf after taking a knee to his low back when being tackled. After x-rays in the locker room were negative for broken bones, he came back to play. But physical exam, those x-rays and clinical judgment weren’t enough. Technology and an MRI was required to confirm the decision as to whether he could return to play.

More than 85% of the United States population will experience low back pain in their lifetime and almost all will have it resolve within a couple of weeks without doing much special. Still, mechanical back pain is the most common cause of disability for those younger than 45 and falls only to number three for those who are older. Almost all are work related, especially for people who use their body as a tool or machine. While a single traumatic event can be the cause of the low back pain, often it is a series of minor traumas that add up to cause the pain. The numerous structures that make up the low back, the bones, ligaments, tendons, discs and nerves, all have to work together to allow the back to function. An injury and subsequent inflammation to any one structure can lead to pain.

The back has many responsibilities including maintaining an erect or upright posture. But perhaps, its most important job is to protect the spinal cord its nerves from damage. Most often the cause of back pain arises from the muscles, tendons and ligaments. The decision point for the care provider is to decide whether the spinal cord or nerves are at risk. If the answer is no, then imaging the back with plain x-rays, CT or MRI is a waste of time, radiation and resources.

Most often, the diagnosis is made by talking to the patient and performing a detailed physical exam. When the pain started is important. Was it acute onset with movement? Or did it arise hours later, perhaps after laying down or getting up in the morning. Understanding the mechanism…was it rotation or torsion of the lower back, or the lumbar spine? or was it flexing or bending forward. That information can help point to what stabilizing structure of the back might be damaged. If the physical exam isn’t exciting and the diagnosis made that it’s all soft tissue (muscle, tendon, ligament), there’s not much to do, except pain control, activity as tolerated and perhaps physical therapy or chiropractic manipulation.

Perhaps the questions that are directed to the potential for nerve impingement or irritation are most important. Is there sharp pain radiating into the buttock or down the leg. Is there numbness or tingling in part of the foot? Nerves that run from the spinal cord can present with pain that follow predictable dermatome patterns and can help determine at what level in the spine damage has occurred. The sciatic nerve is the accumulation of all those nerve roots that supply the leg. Inflammation of any one root can cause significant pain called sciatica. Still, there is little to be gained by x-ray or MRI. The treatment remains pain control and activity as tolerated.

lowerlimbdermatomes

It’s only when signs of impending spinal cord damage does imaging become and urgency. Has the patient lost control of their bowel and perhaps become incontinent of stool? Has he or she lost the ability to empty their bladder and urinate? Is there numbness around the anus or vagina? The questions may seem unrelated to the back but are harbingers of spinal cord disaster and emergent MRI is required.

For most other patients, the best diagnosis and care for low back pain is time and support. Often, symptoms resolve in 2-4 weeks with a combination of rest, ice, heat and anti-inflammatories. Activity as tolerated is always better in mending a back than lying in bed. In some patients, back pain is progressive and further diagnosis and treatment is required, but as opposed to Tony Romo’s x-ray within a few minutes and MRI within 48 hours, the time frame is a lot slower. To be fair, one indication for plain x-rays is in a trauma victim and suspicion of fracture, and being hit by a linebacker qualifies. For most people, however, their trauma is bending over or twisting to pick up a box and that isn’t enough to break bones. (There are always exceptions in medicine and we’ll offer one to little old ladies with osteoporosis who can get compression fractures with little or no trauma).

The stakes are high in the NFL and with player salaries in the millions, there is a want to return the player to the field of play as soon as possible. It causes doctors and trainers yo use technology to bolster their medical opinion. In the real world, the stakes for o every patient are just as high, but it is just as reasonable to trust high touch instead of high tech in caring for their back. If the 85% of the population that will one day experience back pain demand the Tony Romo level of care, unemployment in this country will fall to zero. Somebody will have to build all those MRI machines.

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