Triads in Medicine – Rapid Review for Medical Students

triads in medicine

One of the most convenient ways of learning and remembering the main components of disease and identifying a medical condition on an exam are Triads, and medical students/interns/residents swear by them.

Be it a question during rounds, a multiple-choice exam question to be solved, or even in medical practice, the famous triads help physicians recall important characteristics and clinical features of a disease or treatment in an instant.

Since exam season is here, this could serve as a rapid review to recall the most common medical conditions.

While there are a vast number of triads/pentads available online, I have listed the most important (high-yy) ones that every student would be asked about at least once in the duration of their course.

1) Lethal Triad also known as The Trauma Triad of Death
Hypothermia + Coagulopathy + Metabolic Acidosis

2) Beck’s Triad of Cardiac Tamponade
Muffled heart sounds + Distended neck veins + Hypotension

3) Virchow’s Triad – Venous Thrombosis
Hypercoagulability + stasis + endothelial damage

4) Charcot’s Triad – Ascending Cholangitis
Fever with rigors + Right upper quadrant pain + Jaundice

5) Cushing’s Triad – Raised Intracranial Pressure
Bradycardia + Irregular respiration + Hypertension

6) Triad of Ruptured Abdominal Aortic Aneurysm
Severe Abdominal/Back Pain + Hypotension + Pulsatile Abdominal mass

7) Reactive Arthritis
Can’t See (Conjunctivitis) + Can’t Pee (Urethritis) + Can’t Climb a Tree (Arthritis)

8) Triad of Opioid Overdose
Pinpoint pupils + Respiratory Depression + CNS Depression

9) Hakims Triad – Normal Pressure Hydrocephalus
Gait Disturbance + Dementia + Urinary Incontinence

10) Horner’s Syndrome Triad
Ptosis + Miosis + Anydrosis

11) Mackler’s Triad – Oesophageal Perforation (Boerhaave Syndrome)
Vomiting + Lower Thoracic Pain + Subcutaneous Emphysema

12) Pheochromocytoma
Palpitations + Headache + Perspiration (Diaphoresis)

13) Leriche Syndrome
Buttock claudication + Impotence + Symmetrical Atrophy of bilateral lower extremities

14) Rigler’s Triad – Gallstone ileus
Gallstones + Pneumobilia + Small bowel obstruction

15) Whipple’s Triad – Insulinoma
Hypoglycemic attack + Low glucose + Resolving of the attack on glucose administration

16) Meniere’s Disease
Tinnitus + Vertigo + Hearing loss

17) Wernicke’s Encephalopathy- Thiamine Deficiency
Confusion + Ophthalmoplegia + Ataxia

18) Unhappy Triad – Knee Injury
Injury to Anterior Cruciate Ligament + Medial collateral ligament + Medial or Lateral Meniscus

19) Henoch Schonlein Purpura
Purpura + Abdominal pain + Joint pain

20) Meigs Syndrome
Benign ovarian tumor + pleural effusion + ascites

21) Felty’s Syndrome
Rheumatoid Arthritis + Splenomegaly + Neutropenia

22) Cauda Equina Syndrome
Low back pain + Bowel/Bladder Dysfunction + Saddle Anesthesia

23) Meningitis
Fever + Headache + Neck Stiffness

24) Wolf Parkinson White Syndrome
Delta Waves + Short PR Interval + Wide QRS Complex

25) Neurogenic Shock
Bradycardia + Hypotension + Hypothermia

Further Reading

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Core EM Clerkship Topics

Core EM Clerkship Topics

In the last ten years, there are few published undergraduate emergency medicine curriculum recommendations (Hobgood et al., 2009; Manthey et al., 2010; Penciner et al., 2013; Santen et al., 2014).

Current undergraduate curriculum trends recommend longitudinal and horizontal integration, and the topic lists related to emergency medicine are extensive for medical students.

In this post, we provide International Federation for Emergency Medicine and Society for Academic Emergency Medicine’s recommendations (Manthey et al., 2010; Hobgood et al., 2009).

The chosen topics can ideally be re-discussed in the clerkship during the senior years of medical school.

  • Abdominal pain
  • Altered mental status
  • Cardiac arrest and arrhythmias
  • Chest pain
  • GI bleeding
  • Headache
  • Multiple trauma
  • Poisoning
  • Respiratory distress
  • Shock

Because the length of the rotations can vary between institutions, the topics list can be extended according to the length of the clerkship and local needs.

References and Further Reading

  • Hobgood, C., Anantharaman, V., Bandiera, G., Cameron, P., Halperin, P., Holliman, J., … & International Federation for Emergency Medicine. (2009). International Federation for Emergency Medicine model curriculum for medical student education in emergency medicine. Canadian Journal of Emergency Medicine, 11(4), 349-354.
  • Manthey, D. E., Ander, D. S., Gordon, D. C., Morrissey, T., Sherman, S. C., Smith, M. D., … & Clerkship Directors in Emergency Medicine (CDEM) Curriculum Revision Group. (2010). Emergency medicine clerkship curriculum: an update and revision. Academic Emergency Medicine, 17(6), 638-643.
  • Penciner, R. (2009). Emergency medicine preclerkship observerships: evaluation of a structured experience. Canadian Journal of Emergency Medicine, 11(3), 235-239.
  • Santen, S. A., Peterson, W. J., Khandelwal, S., House, J. B., Manthey, D. E., & Sozener, C. B. (2014). Medical student milestones in emergency medicine. Academic Emergency Medicine, 21(8), 905-911.

How to make the most of your EM Clerkship

How to make the most of your EM Clerkship

Emergency Medicine has something for everyone!

Starting the Emergency Medicine (EM) Clerkship is one of the most exciting times of any medical student’s life, regardless of whichever specialty they plan on specializing in because EM has something for everyone. It is like solving all those questions that begin with ‘A patient presents to the Emergency Department with…’ but in reality, at a faster pace and with more tricky situations. This can make students feel overwhelmed, as they find themselves juggling between books and resources as to which one to follow or which topics to learn, and I am here for just that! To share the approach that helps many students get the hang of EM and make the most of their time in one of the best learning environments of any hospital.

Prepare a list of common conditions

The basic approach would be first to jot down all the problems you can think of.

Here is a list to help you get started: Core EM Clerkship Topics

There are problems that you may be heard a lot such as Chest Pain, Heart Failure, Shock (and it’s types), Acute Coronary Syndrome, Sepsis, Pulmonary edema, Respiratory Failure, Coma, Stroke, Hypoglycemia, Subarachnoid Hemorrhage, Fractures, Head Trauma, Status Epilepticus, Diabetic Ketoacidosis, and Anaphylaxis.

As every doctor you meet will always say, common is common, so always focus on things that you have heard and seen most about, read about them, make notes on their clinical features, differentials, investigations and management. Most importantly, do not forget to read about the ABCDE approach in every critically ill and trauma patient.

Brush up on your history taking and examination skills

Know what to ask and when to ask. Patients in the ED are not in their most comfortable composure, so try to practice and frame questions that provide you with just enough information to make a diagnosis in the least possible time.
The same goes for examination, never forget the basics of examination and their importance. Practice examination as much as you can and you will automatically see it come to you naturally at a faster pace. Also, do not forget focused history and physical examination is a cornerstone of EM practice and saves a lot of time.
Where investigations can help you exclude a differential, 80% of your diagnosis will be built from what you ask, what you see and what you feel. Keep in mind that if you are not thinking or looking for something, you will not see and find it. So, be suspicious of life, organ and limb-threatening problems.

Read about common ED procedures

ABG, Intubation, Central Lines, FAST Scan, Suturing, Catheter and Cannula placement are some of them. As a medical student, you will probably not be required to perform any, but it is good to have an idea about the procedures when you see them. If you can practice, then that is even better, ask a resident or intern to show you how and you can have a go yourself under their supervision! Remember, “see one, do one, teach one.”

Watch videos on examination, interpreting X-rays, & procedural skills

Youtube is an asset when it comes to medical education, make good use of it. There are also plenty of videos on the iEM website that you can watch and learn from.

Interpretation of ECG & X-rays

Google is your best friend for this! You have the list of common conditions, all you need to do is a google search on the most common ECG findings and x-rays in medical emergencies and you will be good to go. You can also always learn these from the doctors around you in the ED, as the more you see and try to interpret, the better you get at differentiating the normal from abnormal.

Books

Before the rotation

Before the rotation, read a review book, recall your basic knowledge from internal medicine/family medicine and surgery because EM almost covers all of the acute problems of those fields. Moreover, do not forget, EM is an independent specialty and has its’ own textbooks.

iEM Clerkship book is a very good source to get started with! Download Now! – iEM Book (iBook and pdf)

If you are the kind, who likes solving questions, the Pretest Emergency Medicine is a great source.

During the rotation

During the rotation – Learning what you see is the best way to keep things in your long term memory. After your shift ends, and you go home, get some rest, recall the cases of the day and read about them on Up to Date/ Medscape or any resource that you prefer, this will help you relate what you saw with what you are reading and will help you recall it better later on.

These are just a few tips to help in making the most of your EM rotation. Remember to study hard, but also practice, brush up on your communication skills, talk to patients, be there for them. The EM Clerkship prepares you for life as a doctor, as you practice every aspect of medicine during this time and learn to answer questions about acute medical problems and their severity when asked by those around you.

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An upside-down cake: the EM differential diagnosis

An upside-down cake: the EM differential diagnosis

How we’re different

When I was rotating on surgery as a medical student, our attending once asked of our small group what may be concerning in the differential for right upper quadrant abdominal pain. A very eager and a somewhat brash student blurted immediately: “Echinococcal cyst!” The attending replied, “Well, that’s true, but if Echinococcal cyst is the first thing you think of as a surgical consultant, you’re crazy!”

On the other hand, take a practicing internal medicine physician like my Dad. He formulates his differentials with a very different strategy, which is: what is the most likely? A chronic cough is bronchitis (even with hemoptysis), pneumonia, GERD or postnasal drip. Shoulder pain is, of course, a sprain, bursitis, or some referred cervical impingement. And so on.

Unfortunately, neither hunting for zebras (an unofficial US name for exciting but rare diagnoses) nor settling for the most common works for emergency medicine. In fact, that is how true diagnoses may get missed and patients may start dying. 

Why we are different

The EM differential diagnosis is a pyramid tipped on its head. It is therefore different from how differentials are approached by many other specialties.

In EM, we first have to think of and rule out the most severe or threatening pathology. That’s a given. But our choices have to come from among the common killers, not Martian viruses or unheard of tumors from a medical encyclopedia. 

Amoebic meningitis is exciting to encounter in your practice. But guess what? Your patient won’t have it. At the same time, for EM physicians things like pulmonary embolus, aneurysm of the abdominal aorta, subarachnoid hemorrhage and necrotizing fasciitis are everyday icons on our cognitive desktops. While less common than a common cold, these things are by no means rare.

Why it is difficult

In EM, one can rest assured that common pathology will present atypically and not quite like the textbook.

Things are further complicated by confounders, mimics and the disjunction of concern.
 
Confounders are concurrent pathologic processes that the patient already has, which tend to get worse due to any new significant disease process or general body stress. CHF and COPD get exacerbated, kidneys become insufficient, anxiety and psychoses go florid and atrial fibrillation accelerates to rapid. How do you spot sepsis or an MI, which is the true cause of it all, underneath layers and layers of abnormal vitals and test results?
 
Mimics are things that pretend to be other diseases. PE presenting with a low-grade fever and a cough, carbon monoxide poisoning posing as geriatric altered mental status, and severe sepsis arriving as chest pain, dizziness and a bumped troponin. Such has happened many times in the past and continues to happen daily at all EDs globally.
 
The disjunction of concern is when your patient is not worried about what you are worried about. They don’t want to get cancer like their neighbor, but they have never heard of a TIA or an AAA. Kawasaki disease? Why don’t you just give my daughter better antibiotics? My uncle died of a heart attack at 35, not a “bisection” or whatever you called it…So I don’t want a CT scan!
 
An EM physician’s focus on ruling out worst-case scenarios may paradoxically contribute to a patient’s distrust at the end of the encounter. The patient’s agenda is to leave knowing what disease they have, while we are often satisfied knowing which horrible things a patient does do not have.

It may take years of practice to be able to persuade someone that you have done due diligence and your professional duty by excluding a whole lot of deadly things, while the exact diagnosis still remains elusive.

Secretly paranoid, openly confident and always nice

We are confident, but also afraid. We have to think of the worst yet possible scenario for any complaint, yet of course anticipate that the actual diagnosis will hopefully be something less severe and quite common – like a migraine. After all, after most CT scans and lumbar punctures, it is not a subarachnoid hemorrhage.

In EM, we are in this perpetual struggle with having to be professionally pessimistic and paranoid on the one hand, yet emotionally supportive and reassuring for the patient on the other. I always teach my students, even nursing trainees, that no one should be leaving an emergency department more scared or anxious than when they came in.

Your job as a rotating trainee in EM is to understand and learn this exact interplay.

Homework

For your attending, but more importantly for yourself and your patients, you have to be as concerned with sepsis from PID on a 16-year-old young woman with fever and abdominal pain as you are with appendicitis. The 86 year old grandmother with Afib but on no anti-coagulation, because she falls a lot is not just TIA or CVA prone. Her embolic clots may just as well be traveling downstream, causing that intermittent or out of proportion abdominal pain called mesenteric ischemia – for which you do not have a good lab test or imaging, by the way.

Here is a brief checklist:

  • For any anatomic complaint or a chief complaint type

    think of several real worst-case scenarios that are not zebras. Can something horrible yet by no means unheard of be presenting atypically? What steps can you take to prove or disprove it?

  • Think of confounders and mimics.

    What else could be going on? Like a stack of dominoes: what happened first, what happened next?

  • Address the patient’s concerns

    while carefully and patiently pursuing your own professional agenda.

  • When it turns out to be something common or benign,

    don’t forget to discuss worrisome signs for which to return. What if you’re still wrong?

If you liked this story, you may like these too!

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Core Topics for EM Clerkship

Core EM clerkship topics recommended by SAEM are ready for students. Feel free to read or listen. And, do not forget to share with your colleagues or students. Sharing is caring!

Shock

by Maryam AlBadwawi Introduction Shock, in simple terms, is a reduced circulatory blood flow state within the body. The inadequate circulation deprives the tissues of its

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Chest Pain

by Asaad S Shujaa Introduction Chest pain is one of the most common symptoms presented in the emergency department (ED), and it is worrisome because

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Gastrointestinal Bleeding

by Moira Carrol, Gurpreet Mudan, and Suzanne Bentley Case Presentation A 61-year-old man with a history of liver cirrhosis secondary to chronic EtOH abuse presents to

Read More »

Headache

by Matevz Privsek and Gregor Prosen Introduction Headache is a subjective feeling of pain, crushing, squeezing or stabbing anywhere in the head. They are typically

Read More »

Respiratory Distress

by Ebru Unal Akoglu Case Presentation A 40-year-old female with a history of diabetes mellitus presents with a complaint of 6 days cough and muscle

Read More »

Multiple Trauma

by Pia Jerot and Gregor Prosen Case Presentation A 28-year old male was a restrained driver in a head-on motor vehicle collision. He was entrapped and

Read More »

Poisonings

by Harajeshwar Kohli and Ziad Kazzi Case An 18-year-old, previously healthy female, presents to the Emergency Department with nausea, vomiting, and tremors. She states 45

Read More »

Cardiac Arrest

by Abdel Noureldin and Falak Sayed Quick link to Spanish Version Introduction A 23-year-old female was brought into the emergency department. Her frantic family members

Read More »

Altered Mental Status

by Murat Cetin, Begum Oktem, Mustafa Emin Canakci  Case Presentation An 80-year-old female presents to the emergency department with a tendency to sleep (altered mental

Read More »

Abdominal Pain

by Shaza Karrar Case Presentation A 39-year-old female presented to the emergency department (ED) complaining of right-lower-quadrant (RLQ) pain; pain duration was for 1-day, associated

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Is Troponin Enough?

You are the emergency doc working in a rural ED. It is the Saturday night at 23:25 and you have three patients with chest pain. All have unchanged ECGs and normal troponins. All feel well now and want to go home if you think their results are okay. What is your plan for each of them?

Patient 1. Isabel D. is a 45-year old female with a history of hypertension. She presented to the emergency department with left-sided sharp chest pain. Her pain started after his evening run, and she vomited once. Her pain continued for one hour, but then it lessened spontaneously. Now she is feeling well, and she wants to go home. Her ECG is completely normal. Her 0- and 3-hour troponins are negative.

Paint 2. Daniel B. Is a 65-year old male with a history of smoking, hypotension and left bundle branch block (LBBB). He is obese. He presented to the emergency department with left-sided heavy chest pain, radiating to his left arm, chin, and back. He went to bed early today, and his chest pain woke him up. For half an hour, he has felt sweaty and nauseated but now he is feeling well, and he wants to go home. His ECG shows LBBB, unchanged compared to his previous ECGs and without Sgarbossa Criteria. His 0- and 3- hour troponins are negative.

Patient 3. Hank P. is a 54-year old male with a history of hypertension, diabetes mellitus and prior stroke with no sequel. For twenty minutes, he experienced a sharp pain in the middle of his chest. His pain had started while he was watching TV and he felt sweaty all in a sudden. he had His ECG shows findings related to left ventricular hypertrophy.  His 0- and 3- hour troponins are negative.

HEART Score

HEART Score was developed to predict the 6-week risk of a major adverse cardiac event of patients with chest pain, precisely in the emergency department setting (1). It outperformed the others, especially in exclusion of low-risk patients (2) Patients with a combination of HEART score of 0-3 and two negative troponins can be safely discharged from ED with no major adverse cardiac events (3). Patients with HEART Score of 4-6 requires admission and are candidates for further noninvasive investigations (1). Patients with HEART Score of ≥7 requires admission and are candidates for early invasive strategies (1).

HEART Score

CategoryScoreExplanationRisk Features
HistoryHigh-risk features
• Middle- or left-sided chest pain
• Heavy chest pain
• Diaphoresis
• Radiation
• Nausea and vomiting
• Exertional
• Relief of symptoms by sublingual nitrates

Low-risk features
• Well localized
• Sharp pain
• Non-exertional
• No diaphoresis
• No nausea and vomiting
Slightly Suspicious 0Mostly low-risk features
Moderately Suspicious+1Mixture of high-risk and low-risk features
Highly Suspicious+2Mostly high-risk features
ECG
Normal0Completely Normal
Non-specific Repolarization Disturbance+1Non-specific repolarization disturbance• Repolarization abnormalities
• Non-specific T wave changes
• Non-specific ST wave depression or elevation
• Bundle branch blocks
• Pacemaker rhythms
• Left ventricular hypertrophy
• Early repolarization
• Digoxin effect
Significant ST Depression+2Significant ST depression• Ischemic ST-segment depression
• New ischemic T wave inversions
Age
<450
45-64+1
≥ 65+2
Risk Factors• Obesity (Body-Mass Index ≥ 30)
• Current or recent (≤ 90 days)smoker
• Currently treated diabetes mellitus
• Family history of coroner artery disease (1st degree relative < 55 year old)
• Hypercholesterolemia

OR

Any history of atherosclerotic disease earn 2 points:
• Know Coroner artery Disease: Prior myocardial infarctions, percutan coronary intervention (PCI) or coronary artery bypass graft
• Prior stroke or transient ischemic attack
• Peripheral arterial disease
No known risk factors0
1-2 risk factors+1
≥ 3 risk factors or history of atherosclerotic disease+2
Initial Troponin
≤ normal limit0
1-3 x normal limit+1
> 3x normal limit+2
Please read articles 1,2,4 for more information.

Now, let’s look back on our patients.

Isabel’s pain has both high-risk (exertional, left-sided pain with vomiting) and (sharp pain, no diaphoresis) features; therefore, her pain is moderately suspicious. (H: +1) Her ECG is completely normal. (E: 0) She is 45 years old. (A: +1). She has one risk factor, hypertension. (R: +1) Her troponins are normal. (T: 0) Her HEART score is 3, and she can safely go home from the emergency department. The expected MACE rate in 30 days is 0%.

Daniel’s pain has mostly high-features (left-sided, radiating heavy chest pain with nausea and vomiting); therefore his pain is highly suspicious. (H: +2) His ECG is not completely normal but free of new ischemic changes. (E: +1) He is 65 years old. (A: +2). He has three risk factors, smoking, obesity, and hypertension. (R: +2) His troponins are normal. (T: 0) His HEART score is 7, and he is a candidate for early invasive intervention. You should admit him and call the cardiologist.

Hank’s pain has both high-risk (middle-sided chest pain with diaphoresis) and low-risk (non-exertional, sharp pain) features; therefore, his pain is moderately suspicious. (H: +1) His ECG is not completely normal but free of new ischemic changes. (E: +1) He is 54 years old. (A: +1). He has three risk factors, hypertension, diabetes mellitus and prior stroke. (Note that prior stroke alone earns two points) (R: +2) His troponins are normal. (T: 0) His HEART score is 5, and he is a candidate for noninvasive investigation. You should admit him.

PEARLS and PITFALLS

  1. ECG: If the ECG shows STEMI, do not wait for troponin or consider the HEART score. Call the cardiologist and consider activating angiography unit for the primary PCI.
  2. Troponins: If you first troponin is highly abnormal, do not wait for the second troponin or consider the HEART score. Call the cardiologist and consider activating angiography unit for the primary PCI. Additionally, the magnitude of change between the first and the second troponin is important in diagnosing acute myocardial infarction (5).
  3. Clinical Gestalt: You will gain a clinical gestalt over the years. If your clinical gestalt and any scoring disagree, always stay on the safe side for the patient’s benefit (4).
  4. Patient Safety: In the original study, the HEART score was combined with only one troponin. The adverse event rate was 2.5% for the HEART score 0-3 patients, 20.3% for the HEART score 4-6 patients and 72.7% for the HEART score ≥7 patients. Therefore, the author believes, the HEART score combined with two troponins is safer in the discharge of low-risk patients. Low-risk patients (i.e., HEART Score 0-3) with negative two troponins had no MACE within 30 days (3).

Suggested Chapters

Chest Pain by Asaad S Shujaa

Acute Coronary Syndrome (ACS)

by Khalid Mohammed Ali, Shirley Ooi

REFERENCES

  1. Six, A. J., Backus, B. E., & Kelder, J. C. (2008). Chest pain in the emergency room: value of the HEART score. Netherlands Heart Journal, 16(6), 191-196. – link
  2. Radecki, R. (2013). Time to Move to the HEART Score. Available at: http://www.emlitofnote.com/?p=440 (Accessed: 17/07/2018) – link
  3. Mahler, S. A., Riley, R. F., Hiestand, B. C., Russell, G. B., Hoekstra, J. W., Lefebvre, C. W., … & Herrington, D. M. (2015). The Heart Pathway Randomized Trial: Identifying Emergency Department Patients With Acute Chest Pain for Early Discharge. Circulation: Cardiovascular Quality and Outcomes, 8(2), 195-203. – link
  4. Hyunjoo, L., & Rodriguez, C. (n.d.). HEART Score for Major Cardiac Events. Available at: https://www.mdcalc.com/heart-score-major-cardiac-events#evidence (Accessed: 17/07/2018) – link
  5. Roffi, M., Patrono, C., Collet, J. P., Mueller, C., Valgimigli, M., Andreotti, F., … & Gencer, B. (2016). 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation: Task Force for the Management of Acute Coronary Syndromes in Patients Presenting without Persistent ST-Segment Elevation of the European Society of Cardiology (ESC). European heart journal, 37(3), 267-315. – link

FURTHER READING