Category Archives: Rapid Learning

Pattern Recognition In Diagnosis

XBalloon-passed gas

Previous blogs have discussed memory techniques for rapidly learning and remembering information in medical school:

•  Understanding

•  Visualization

•  Ridiculous Associations

•  Substitute Words and Pictures

•  Ditties

•  The Linking Method

•  The Peg Method

•  The Memory Palace

•  Chunking

•  Acronyms

•  Hands-On

Apart from these memory methods, there is another aspect of learning that requires more time to acquire, the ability to quickly recognize disease patterns; this depends on experience.

Often a patient presents with a number of symptoms and signs that may all point to one particular disease; or they may be the result of more than one disease; or some signs and symptoms may be red herrings.  Without experience, there may be a tendency to create a differential diagnosis that is too large or too small, and without proper assignment of correct probabilities to the various potential diagnoses.

For instance, my wife not infrequently experiences headaches in the middle of the night. When I look up the differential diagnosis for this in one of the computerized programs for differential diagnosis, the leading diagnosis comes up as “massive intracranial hemorrhage.” Obviously, this is not true, but the computer program spins this out because the data was collected from hospital admissions, not outpatient visits.  Someone admitted to the hospital with headaches arising in the middle of the night likely has something more serious than someone who is not admitted.

The ability to correctly formulate a differential diagnosis depends on the physician’s experience — whether it is outpatient or inpatient, and even which area of the country or world, where certain diseases are more prevalent than in other areas.  Gaining experience  requires time. That is why the medical student’s differential diagnosis is often so long, and not necessarily listed in order of disease probability.  Eventually, though, the physician learns to quickly determine the most likely diagnosis, based on known disease patterns.  It is important, though, that the physician does not become sloppy and superficially misinterpret patterns by rushing to a diagnosis in the midst of a busy office (or, to save time, simply adopt a shotgun approach, ordering unnecessary tests that may be invasive or expensive).

Humans are expert in recognizing patterns, but often come to the wrong conclusion when they read too much into a pattern (e.g. a face on a pizza).  The ability to efficiently arrive at a medical diagnosis comes with learning on a longer time scale than the memory techniques listed above.

Learning Through Case Problems

"Continue the antibiotic ..... and remember to drink lots of toilet water."

Previous postings on this blog pointed to a number of different memory methods useful for rapid learning in medical school:

•  Understanding

•  Visualization

•  Ridiculous Associations

•  Substitute Words and Pictures

•  Ditties

•  The Linking Method

•  The Peg Method

•  The Memory Palace

•  Chunking

•  Acronyms

•  Hands-On

Of course, once you use one or more of these methods it helps to review the information.  For certain subjects it also helps considerably to invest extra time to practice cases that put the information together into a clinically coherent whole.

For instance, in neuroanatomy, after learning particular structures in anatomy, it is important to practice clinical cases where you can combine this information to determine where in the nervous system a patient’s problem lies.

The subject of acid-base, fluids, and electrolytes contains a bewildering array of facts that have to be organized and put together in order to apply to a case.  What is the diagnosis?  What is the treatment?  Which fluid bottles should you hang up?  Case examples help consolidate this information for application to a patient.

In cardiology, it is not enough to just read a chapter on EKGs.  The real learning comes on practicing the interpretation of EKGs with many examples.

In psychiatry, clinical cases help to fine-tune what medications and dosages to use for the individual psychiatric disorders.

In some medical curricula, students in the first two years of medical school do divide into groups that discuss individual case problems.  This approach can be helpful for the particular case situation, but there is a drawback when a case takes up too much time in the group.  There are so many case situations that have to be mastered, and spending too much time on just a bare few can be an inefficient use of time.

Try to use textbooks that include case problems in those subjects in which it is important to bring diverse facts together to diagnose and treat patients.  Case problems alone, however, are insufficient to learn a subject.  You also need a background in the subject  before approaching the clinical problems.

MedMaster has a number of books that include case problems for those areas mentioned above:

Clinical Neuroanatomy Made Ridiculously Simple
Acid-Base, Fluids, and Electrolytes Made Ridiculously Simple
Clinical Cardiology Made Ridiculously Simple
Clinical Psychopharmacology Made Ridiculously Simple

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Which do you prefer – eBooks or print books?  MedMaster is considering converting a number of its titles to eBooks and is interested in your opinion as to the usefulness to medical students of eBooks, compared with print books.

How Reliable Is Your Medical Information?

Perhaps oxygen wasn't such a good idea!

When working in the hospital and medical office during the clinical years,  it is common to receive pearls of wisdom from interns, residents, and attendings.  How reliable is this information?  And how reliable is the information we receive from lectures, journal articles, books, and drug reps?

A lot of information is  passed around, and since some of it is wrong, it is important to rely on the best sources available.  In the 1980’s, some of the best minds in medicine made a disastrous mistake.  It was known that significant cardiac arrhythmias were correlated with death.  A search was undertaken for drugs that would reduce such deaths.  But rather than using reduction of deaths as an end point in the drug studies, it was easier to adopt a “surrogate” endpoint, namely whether the drug reduced arrhythmias.  If a drug reduced arrhythmias, it presumably would also reduce deaths.  It was not adequately considered that the drugs might have unexpected harmful side effects that would in fact worsen the problem and contribute to death.  Antiarrhythmics became widely prescribed, even for non-life threatening arrhythmias, leading to many unnecessary deaths (which initially were felt to be due to the heart disease, rather than the drugs), until studies were properly done to assess whether the drugs actually saved lives.  They didn’t; they killed thousands of people.

There is so little time to read and evaluate the medical literature, particularly the Materials and Methods sections of research articles, and there is an unfortunate tendency to rely on the word of physicians above us in the hierarchy, or on drug reps, or on research reports (particularly those funded by drug manufacturers) that may have biased and erroneous conclusions.  It is necessary to know how to read and evaluate a research article.  This requires some knowledge of biostatistics.  For further information, see Ann Weaver’s brief and intuitive book, Clinical Biostatistics Made Ridiculously Simple, which focuses on the pitfalls of clinical research reports and how to evaluate them.

It is also important to use reliable medical search engines on the Internet, since the Internet contains lots of unreliable information. Such search engines are described on the MedMaster search engine page.

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Do you prefer  eBooks or print books?  And why?  Feel free to comment.

How To Study Pharmacology

The Seven Dwarves' Medicine Chest

When I was in medical school, Pharmacology was taught by Alfred Gilman, a coauthor of  Goodman and Gilman’s Manual of Pharmacology and Therapeutics, a superb reference text, both then and now.

However, I had great difficulty in grasping an overall picture of the subject through this reference text.  It was too big; after reading one drug after another, the drugs soon started blending into one another, becoming difficult to sort out and remember.

What is the best way to learn Pharmacology?  This goes to the question of what facts are important to memorize and which are not so important to memorize but can be looked up in a reference text or computer program.

In Clinical Pharmacology Made Ridiculously Simple, the author, James Olson, has sorted out the general characteristics of each drug group at the top of the page, for understanding and memory.  Other details, particularly those contrasting the individual drugs in a given group with one another, are placed in a table for cross reference at the bottom of the page.  Such information can be looked up rather than memorized, except for certain features that are highly characteristic of one drug in comparison with the others.

It is helpful to have a good reference text in addition to the small book that quickly enables the reader to grasp general principles.

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What is your opinion about the usefulness of eBooks versus print books?  Which do you prefer?

How To Study Biochemistry

In 25 years of teaching medical students, I found that Biochemistry is the course that students have most difficulty relating to for clinical relevance.  While Biochemistry has much clinically relevant information, the material students are taught often does not reflect this.

I think this is because there is a big difference in what is important to PhD students and what is important to medical students.  For instance, ALT and AST are liver enzymes that are vitally important to the function of cells.  Their detailed biochemical reactions are important to the PhD student, but not to the medical student.  It is more important clinically to know that these enzymes leak out of damaged liver cells and are useful as markers for liver damage.

As another example, creatinine is a waste product of muscle biochemistry.  It is not so important to the PhD student, but very important to the medical student as a marker of muscle and kidney damage.

It would help to have more clinicians teaching the basic sciences and providing a more clinical focus.

Of course, if your instructor emphasizes topics of greater interest to PhD students, you need to learn that, as well as facts that are asked on the USMLE.  But teaching would be improved by emphasizing clinically important areas.

There is a problem with just rote-memorizing isolated facts.  Somewhere along the line it would help to understand Biochemistry as an overall whole, particularly in a clinical context, for future practical use.  For instance, there is much discussion about the value and side effects of HMG CoA reductase inhibitors (“statins”) in suppressing cholesterol synthesis.  It helps to see this enzyme in the context of a broader Biochemistry map to understand the pathways involved in cholesterol synthesis and what may be affected by suppressing it.

In Clinical Biochemistry Made Ridiculously Simple, I have tried to do just that, present the clinically relevant points in Biochemistry (particularly the metabolic pathways and the diseases that affect it) on a single map that can be grasped as a whole.  It is not a reference text, which disappoints some readers.  I suggest that readers also acquire a good reference text, bearing in mind that it can be very difficult to see the overall picture in a reference book.  The best way to study Biochemistry is to first grasp the overall picture in a small book, but also have a reference text and your class notes to fill in on other details.

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What do you think about using eBooks versus print books?

The Best Medical Apps

Treatment that works for one patient does not necessarily work for another.

The term “app” (application) generally refers to a small, specialized program that is downloaded onto a hand-held (mobile) device such as an iPhone or tablet, although the term is also used for laptop and desktop computers.

There are over 5,000 medical apps, which are continually evolving.  There can be “app overload,”  where many apps are downloaded, but few are used.  What sort of apps should you look for?

Ideally, a medical app for a mobile device should provide rapid, useful information at the bedside or office visit (“point-of-care”) in such areas as:

Drugs (dosages, side effects, drug interactions)
Differential diagnosis
Current workup and treatment
Lab values
Calculation formulas and algorithms
Specialty items such as heart sounds, EKGs, dermatologic diagnosis, radiologic images, and vision testing, depending on your needs.

The top 5 applications that are favored by students at Harvard Medical School (http://mobihealthnews.com/10745/top-five-medical-apps-at-harvard-medical-school/) are:

  1. Epocrates:provides drug dosages, drug side effects and interactions, pill ID, lab values, calculation formulas, and algorithms.
  2. VisualDx Mobilecontains dermatologic images and diagnosis algorithms.
  3. Dynamedprovides up-to-date approaches to diagnosis and treatment.
  4. Unbound Medicine uCentralhas many apps that can be combined and customized for your particular needs and interests.
  5. iRadiologyshows a compendium of radiologic images.

I add a few more:

WebMD provides a rapid guide to symptoms, conditions, drugs and treatments, including first aid information.

Medscape provides information about drugs, including over-the-counter and herbal medications, diseases and conditions, procedures and protocols, and drug interactions.

MurmurPro offers a set of heart murmurs.

Vision Test provides vision tests.

Mediquations:  While Epocrates offers calculation formulas, Mediquations provides more formulas and actually does the calculations.

In addition to the above apps, there are also Internet medical search engines that can look for reliable and specialized information, as opposed to the sometimes unreliable information that is found through general search engines, such as Google.  A list of these search engines can be found at the MedMaster website, which also offers a downloadable app, called MedSearcher (free), which allows quick access to the major medical search engines. MedSearcher presently is only available for computer use on Mac and Windows.

All the above apps offer isolated point of information.  Apart from individual facts, it is also important to have a general understanding of the subject and field.  This requires a fair amount of reading, which for many students would be tedious on a small hand-held mobile device like an iPhone.  It would require a print book or an eBook reading tablet.  MedMaster specializes in books that promote understanding.

Do you have a favorite app that you would like to share?  Please feel free to comment.

How To Study Neuroanatomy

The director of medical student cardiology training at the University of Miami once told me that cardiology was really not that difficult to learn, since it was based on a few general principles, but that neuroanatomy was difficult, since there were so many isolated facts that are difficult to digest.

I found this conversation interesting, since I had experienced just the opposite.  Cardiology to me was always nebulous; there were just too many facts to learn, especially drugs and their effects, and I always had difficulty with cardiology.  Neuroanatomy, though, seemed far simpler, since, to me, a few general principles conveyed the essence of the subject.  It occurred to me that the learning of a subject has a lot to do with the grasping of general principles.

For instance, there are some 100 billion neurons in the brain and in the range of a quadrillion synaptic connections (connection points between nerve cells).  This would surely be an overwhelming amount to learn.  However, it is interesting from a clinical standpoint that of all these synapses, there is only one that is of clinical significance to know about in evaluating a patient.  That is the synapse that separates an upper motor neuron from a lower motor neuron.  Where the synapse is located makes a big difference in the kind of paralysis that a patient experiences, whether of the upper motor neuron kind or the lower motor neuron kind (I won’t go into the details here).  Other than that synapse, it is the pathway along which information flows, rather than the number of synapses in that path that is important.  Whether or not the pathway has one synapse or many within it is unimportant in making a diagnosis as to where the problem lies. This simplifies the study of the subject.

As an example, the right side of the brain connects with the left environment of the body.  Thus, an injury to the right brain will result in sensory loss or weakness on the left side of the body.  It is not necessary to know where all the synapses lie along these pathways to know this.  Who would concern the physician more, a patient who complains of a right-sided headache and weakness and lack of sensation on the right side of the body, or a patient who complains of a right-sided headache and weakness and lack of sensation on the left side of the body?  It is the latter, because a problem with the right brain should not affect the right side of the body.  The location of the synapses is not so important in making this determination.

In learning neuroanatomy, then, it is more important, at least at first, to learn the general principles of pathway layout, rather than the location of synapses.  If you want to learn all about synapses too, it would be better to first understand the general principles of direction of flow of the pathways, then move on to greater detail.  This is the approach I have taken in Clinical Neuroanatomy Made Ridiculously Simple.

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Which do you prefer, eBooks or print books? And why? Your opinion counts!

How To Study Anatomy

In learning Anatomy, I think it is better to first learn through conceptual diagrams, rather than through photos of actual anatomy.  Photos of dissections, particularly those of formaldehyde-fixed specimens, contain fascia (connective tissue) and other features that obscure the conceptual picture of what connects with what.  In our medical school anatomy program, we had available a series of stereoscopic slides of actual dissections.  Few students used them.  During my ophthalmology residency, I also found relatively useless a book of photos of orbital dissections.  It is better to learn the anatomy conceptually, as through line drawings, and then fine tune this knowledge when learning surgery using unfixed tissue, having first learned the anatomy conceptually.

Anatomy is a very visual subject.  Here, a good way to learn the anatomy is to distort it into pictures that are common knowledge.  A typical vertebra, for instance, looks like a snowman, whose arms, legs, shoulders, and head resemble the actual vertebral anatomy (see below).  While learning other people’s mnemonics can be very helpful, they are often longer-lasting if they are your own.

From Clinical Anatomy Made Ridiculously Simple, by S. Goldberg, MedMaster

Ditties (e.g. “C3,4,5 keep the diaphragm alive”), acronymns (e.g. “SCALP” for layers of the scalp: Skin, Connective tissue, Aponeurotic layer, Loose connective tissue, Pericranium), and ridiculous associations (e.g. for cranial nerves 7 and 3, which open or close the eyes — see below) are also useful for learning anatomy.  A collection of such mnemonics may be found at medicalmnemonics.com.

CN7: A hook - closes eyes. CN3: 3 pillars - opens eyes. From Clinical Neuroanatomy Made Ridiculously Simple, by S. Goldberg, MedMaster.

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Which do you prefer, eBooks or print books?  Why?  Your opinion counts.

Benji’s Shot

Romance on the surgical service

Sometimes, an otherwise complicated diagnosis can be made with a simple observation, without requiring many procedures or expensive tests.  Witness the case of Benji:

One day, a neighbor frantically knocked on my door and told me that she could not arouse her 6 year-old son, Benji.  I raced over to the house to find Benji lying on the couch, and indeed it did not seem possible to awaken him.  A preliminary neurologic exam revealed nothing wrong.  I then raised Benji’s arm above his face and let go.  Now, when a person is really unconscious the arm will hit his face.  However, if he is faking, the arm misses, since the patient does not want to hurt himself.  Benji’s hand missed.

I then announced to Benji, that since I could not wake him up, I would have to give him a big shot in the behind with a needle that he would not feel since he was not awake, and that I was going out of the room to prepare the shot.  I left the room with Benji’s parents and came back about a minute later.  Benji was gone.  He was hiding behind the couch.

So arriving at a complex diagnosis is not always difficult when there is a pearl that shows the way.

Learning Speeds In Medical School

Heroic measures in cardiac arrest

In the classic fable of the Tortoise and the Hare, the tortoise wins the race against the hare by slow and steady persistence.  There are some students who quickly grasp concepts and facts, and have a steep rising learning curve.  Others are slower, but with persistence, can not only achieve the goal, but achieve a greater degree of knowledge and understanding than quicker learners.  Their learning curve may rise slower, but end up higher.

I was a relatively slow reader in medical school.  It sometimes felt like I was miles behind and would never catch up.  However, I eventually learned that understanding key concepts, as opposed to simple rote memorization of isolated facts, can quickly reduce the gap.  Once one has understanding, the facts are more easily organized and remembered.

If you are having difficulty keeping up,  you may not be as far behind as you think. Sometimes, understanding a few key points quickly closes the gap.  I suggest trying to understand, rather than simply rote memorize, and bear in mind that slow and steady adds up down the line.

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Which do you prefer, eBooks or print books?

Studying In The Clinical Years

Hansel and Gretel luck out.

It is interesting that in medical school there is no course in medicine; you have to learn it through patient contact and deciding on your own what to read. It is a different kind of studying than in a course, where the instructor assigns a specific number of pages each day.

How should you study?

One way would be to set aside a certain amount to read each day in a large textbook, such as the excellent 4000 page reference book, Harrison’s Principles of Internal Medicine, reading it a little each day progressing from beginning to end.  Or you could read journal articles.  However, it can be  difficult, particularly when tired, to come home and focus attention when the literature does not pertain specifically to the patients you just saw.

It is more effective to prepare a number of questions each day that relate to the patients you encountered that day.  What is the differential diagnosis?  What are the diagnostic tests?  What are the treatment options?

There are a number of advantages to focusing study on the patients you encountered that day:

1.  You will be more attentive when looking up specific information that relates to the patients you have just seen than to read material that, however important, does not relate to the patient at hand.

2.  When presenting at rounds the next day, you want to appear sharp and informed.  You can do so by reading up on the patients who will be presented at rounds.

3.  Over the long run, by studying this way each day you will accumulate a knowledge of the most common presentations in the hospital.  You can’t know everything.  You can, however, know the most common situations.

In the old days, before computers and the Internet, one had to rely on reference texts, which could be out of date, and journals.  One could also go to the library and take out the voluminous Index Medicus and search out papers that pertained to your subject of interest.  Frankly, I was too tired to go to the library.

Now, with Internet access and medical search engines, it is relatively easy to quickly find the specific information that interests you.  Despite the explosion of new medical information, this is balanced by easier access to that information, and access continues to improve.

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Which do you prefer – eBooks or print books?

Memory Techniques for Med School #11 Hands-On

Centipede referral for hands-on approach

HANDS-ON
Despite the value of the 10 memory methods discussed in the preceding posts, perhaps the best teacher of all is the hands-on interaction with the patient. There is great truth to the patient being the best teacher. While we struggle with difficult hours and clinical situations on the wards and clinics during medical school, internship, and residency, it helps to bear in mind that the experience will be very valuable.  There arises a solid core of judgment and knowledge, ingrained in memory, from the experience of interacting with patients.

Which memory and learning techniques do you find most valuable in your medical studies?
What do you think of eBooks versus print books?