The IM Reasoning podcasts are yet another outstanding medical podcast series.
This post references EPISODE 43: STC LIVE IN PERTH [Link is to the podcast and show notes] AUGUST 01, 2018.
The podcast is a great demonstration of how to do clinical reasoning
And the podcast goes over the use of Illness Scripts and Problem Representations for clinical reasoning. Both tools are used for improving the physician’s diagnostic skill. I have placed some resources on these tools in Resources after this post. I will be making excerpts on Illness Scripts and Problem Resources in the near future [And I will link to them here].
You can also watch this episode on YouTube and I listened to the podcast twice and watched it once. And I went through the video one more time to make the transcript (using my brand new So here is the YouTube video:
The format in this episode is that moderator, Dr Michelle Johnson, emergency physician, gives Drs Nicolas Szecket and Art Nahill, the podcast authors, a clinical case in bits and pieces.
After each little piece of information, the doctors construct a differential diagnosis based on the information that they have been given.
Then the moderator gives them a little more clinical information and the doctors revise their differential diagnosis based on the new information.
The process continues until the doctors have received all of the clinical information (again in bits and pieces). And then based on all the evidence, Drs Szecket and Nahill give us their final diagnosis. Then the audience and the doctors find out if they were right. The moderator will give us the final diagnosis.
This method gives us an incredible look at the way excellent doctors “think like a doctor” to help their patients.
Podcast Time Stamps:
1:56 – 3:50 Dr. Johnson gives us the initial clinical history.
The patient is a 60 year old patient who has lived in Broome, Australia for her whole life and has been in good health.
“She lives a very clean life. She is a vegan. She has two adult children and is separated from her long time partner of 25 years. She lives alone. Gwendolyn is an avid practitioner of yoga. She meditates twice a day in the Buddhist tradition and travels to western Japan for a spiritual retreat annually. She is an artist and makes a living selling her paintings, . . . sculpture, and jewelry. . . . She owns a large block on the outskirts of town. Gwen enjoys gardening and has a large vegetable and herb garden. . . . She drinks water from her own well. She has concerns about flourinated water. She spends her days working in her studio behind her house. She does smoke a small amount of cannabis [but not frequently]. She does not drink alcohol.” “So the story we have is [that] she has presented for the third time in a week; first to the ED, then the GP, and then the GP again with increasing pain in her lower back, hips, and upper thighs.” And that is all they get to start their thinking.
3:50 – 8:30 And with this initial clinical history the doctors start the discussion. And actually, so far, they have been given very little data to work with.
But there is a reason why they start here.
Dr. Nahill states that [physicians] “at various points along the course of hearing a case, they need to come up with problem representations and by problem representations I mean short succinct statements that are in a medical jargon that describe what it is that we’re trying to solve so that we can then work on a differential diagnosis.
So our problem representation at this point in time is that we’ve got a sixty year old healthy vegan woman with progressive pain in her lower back, hips, and upper thighs for three months.
So it is sort of a subacute coming into chronic chronic presentation. And from that, even without getting any more information, we like to generate differential diagnoses. There are methods and shortcuts that we can use to come up with differential diagnoses.
And so for pain. . . .
Dr. Szecket interrupts Dr. Nahill to say [at 5:47]
The other thing to say about the problem resolution is that it is sort of a crystallization of the key features of the case. But you can also think of it as, if you didn’t have an illness script for what you’re hearing – if it didn’t immediately come to you what the diagnosis might be – you might go on to Google. And what you put in your problem representation actually should be what you put in the Google search line to come up with the diagnosis. Now we may not have enough information at this early stage, but that’s what we’re trying to do with the problem representation at every step.
Now Dr. Nahill resumes his discussion of his method of approaching pain.
So my approach to coming up with a differential diagnosis for pain is to just think anatomically. . . . I think of what’s in that area where she’s having pain. There are bones and with bones I think very simply [about what can happen to them – they can break from trauma or osteoporosis or osteomalacia or from nutritional deficiency. They can develop a neoplasm (osteolytic or osteoblastic), infection, marrow replacement.
So what else could be causing this woman’s pain? Possibly joints. At this point in time it could be muscle, nerves. It could be a vascular problem.
I’ve certainly seen patients with aortic dissection present with vague symptoms although this has been going on for a little bit long for that.
So pelvic pathology, certainly ovarian pathology, endometrial pathology. And then, obviously, there is retroperitoneal spaces as well.
So I think in a very anatomical approach and this is sort of my back of the envelope, back of the napkin differential diagnosis.
And Dr. Szecket adds:
The one thing I will say before [Dr. Johnson] goes on is – for some reason we were given a lot of social history right at the beginning. And that is not usually how we have a case presented to us. . . . and usually the social history comes a bit later. So I don’t know if [the person writing up the case] is just trying to remind us that we should always think of these things or just [leading us astray] or give us a clue.
8:30 – 10:25 Dr. Johnson now gives us more clinical history about the three month course of the illness.
The hip pain was initially intermittent but now is persistent and is increasing in severity. The discomfort is to the point that she’s walking in a slow waddle. She’s not been able to do many of the yoga poses that she is so proud of. And gardening is now impossible. Her naturopath has prescribed a combination of tumeric powder and copper daily. She thinks it has helped her. She has been feeling somewhat lethargic and rundown which is unusual for her. She does not think she has had any fevers, night sweats, chills or rigors. She’s sleeping okay, a little more than usual. She has not had any weight loss. She is very thin but this is long term. Essentially, it is a very unrewarding systemic inquiry [Review of Symptoms]. No history of trauma, no features of abdominal features at all – no diarrhea [or] constipation. She’s got a little bit of nocturia but no dysuria or incontinence. No headaches, no visual disturbances, no respiratory symptoms, no chest pain. Etc. Nothing much wrong. She is losing her smell. The incense candles that she burns every day are difficult to appreciate. She doesn’t have any joint symptoms other than her lumbar spine and hips. Gwen is post-menopausal by ten years and has had no pv bleeding or climacteric symptoms for five years. She has never had a fracture of her spine, hip, or wrist. She had two uncomplicated pregnancies in her twenties. . . . She’s had a bit of anemia thought to be [?]. She’s had a bit of iron. . . . She’s never had immunizations because she’s very concerned about mercurial salts used in the production. And she has had no history of cancers. And the medications were just as you heard – the tumeric and copper.
10:25 – 15:25 And using this new bit of information Dr. Szecket continues the case analysis and clinical reasoning. After each new bit of clinical information the physician should restate the problem formulation integrating the new information with the previous information
15:25 – 17:40 And now Dr. Johnson gives us some more clinical information on the examination. Basically her physical exam is completely normal except for the usual Australian sun damaged skin. No active joint signs and basically eveything is negative. Pt does have anosmia.
17:40 – 19:35 And now Dr. Nahill analyzes the new info.
And even though her physical exam was unexciting, there were lots of pertinent negatives there that are pretty important, I think, to consider.
And Dr. Nahill restates the problem representation given the new information that he has analyzed.
19:30 – 20:10 Dr. Johnson gives us more information. The ECG is normal. Dipstick urine shows proteinuria and glycosuria. However, her blood sugar is normal. The rest of the urinalysis is normal including a microscopic exam. Her VBG is normal.
20:10 – 21:37 Dr. Szecket continues the analysis integrating the new data. And the abnormal U/A is a real abnormality that can’t be ignored. It must be explained. And the only thing that Dr. Szecket can think of for glucosuria is diabetes. But the patient does not have diabetes as her blood sugar is normal. Since the blood sugar is normal, she doesn’t have diabetes and something else is going on in the kidneys.
21:37 – Dr. Johnson continues the case presentation. Pelvic and hip x-ray shows osteopenia with signs of osteomalacia. Multiple stress fractures involving the pubic rami and femoral neck consistent with Looser Zones/pseudofractures.* The LS spine shows an osteoporotic compression fracture. And renal US showed bilateral small kidneys.
*Looser zones from Radiopaedia:
Looser zones, also known as cortical infractions or Milkman lines, are wide, transverse lucencies traversing part way through a bone, usually at right angles to the involved cortex and are associated most frequently with osteomalacia and rickets. They are pseudofractures and considered a type of insufficiency fracture. Typically, the fractures have sclerotic irregular margins and are often symmetrical.
Aetiology
Start here
Additional Resources:
(1) Introduction to Exercises in Clinical Reasoning – Clinical Reasoning Exercises From The Journal Of General Internal Medicine of the Society of General Internal Medicine
(1) Problem Representation Overview – Clinical Reasoning Exercises From The Journal Of General Internal Medicine of the Society of General Internal Medicine
(1) Illness Scripts Overview – Clinical Reasoning Exercises From The Journal Of General Internal Medicine of the Society of General Internal Medicine
(1) Dual Process Theory Overview – Clinical Reasoning Exercises From The Journal Of General Internal Medicine of the Society of General Internal Medicine
