In today's hyper-connected world, content is almost a non-issue. When we click on the web, tons of educational resources can be found in websites, blogs, YouTube and in medical education, a recent crowd-sourcing, crowd-sharing concept has emerged - FOAM (Free Online Access Meducation). In recent years, I've got caught up with the FOAM virus too! In this set of slides, I recommend the resources that I've found useful. There are many many more out there, but I think these are the ones that should help a resident or a physician in emergency medicine get started on FOAM, embark on a life-long learning, and use them for blended learning or flipped learning as well.
Thursday, May 14, 2015
Recommended Web Educational Resources Related to Emergency Medicine - To Get You Started!
In today's hyper-connected world, content is almost a non-issue. When we click on the web, tons of educational resources can be found in websites, blogs, YouTube and in medical education, a recent crowd-sourcing, crowd-sharing concept has emerged - FOAM (Free Online Access Meducation). In recent years, I've got caught up with the FOAM virus too! In this set of slides, I recommend the resources that I've found useful. There are many many more out there, but I think these are the ones that should help a resident or a physician in emergency medicine get started on FOAM, embark on a life-long learning, and use them for blended learning or flipped learning as well.
Wednesday, January 18, 2012
Heuristics and Cognitive Biases in Decision Making During Clinical Emergencies
Physicians in emergency department make many decisions in the course of a working shift, some of which can have high consequences. Furthermore, emergency departments often have unpredictable and variable patient volume load as well as clinical acuity. Given the unfavorable nature of such environment, emergency department is often a place that is vulnerable to error. Under such circumstances, a physician in emergency situation often employs a compendium of heuristics (Croskerry et al, 2009).
Heuristics are mental shortcuts or “rules of thumb” or “gut-feeling” (Croskerry et al, 2009) used to assist a physician to rapidly make decisions without formal analysis. It is largely a form of gestalt pattern recognition that is intuitive and its accuracy is dependent on the experience of the physician. Two heuristics that are considered essential when faced with an emergency situation are the “rule-out-worst-case-scenario” and the sick/not sick dichotomy (Croskerry et al, 2009).
When properly applied, these heuristics can be beneficial, but they will occasionally spell disaster when a number of cognitive biases are overlooked. Among the important cognitive biases in clinical medicine are:
- availability bias – it refers to our tendency to judge things as being more likely, or frequently occurring, if they readily come to mind. Therefore, a recent experience with a disease might inflate our likelihood to diagnose the patient with this disease
- anchoring – it refers to out tendency to perceptually fixate on to the salient features in the patient’s initial presentation at an early point of the diagnostic process and failing to adjust our initial impression even in the light of later information.
- confirmation bias - it refers to our tendency to look for confirming evidence to support the diagnosis we are “anchoring” to, while downplaying, or ignoring or not actively seeking evidences that point to the contrary.
- search satisficing – it refers to our tendency to stop looking for alternate or even coexisting diagnoses when we have found one. A classic example of this is the tendency of the physician to call off the search for a second fracture once he thinks he is “sufficiently satisfied” with finding the first fracture (Croskerry et al, 2009).
Ultimately however, the application of heuristics in clinical medicine is inevitable, particularly in emergency situations where every minute counts. For example, in a case of witnessed ventricular fibrillation (VF), immediate step of resuscitation and defibrillation is called for. In such cases, the physician must be trained with the ability for gestalt pattern recognition of VF even within the ‘blink’ of an eye. No time should be lost in searching for the underlying causes of the ventricular fibrillation.
The question, therefore, is not whether the use of heuristics can be minimized or not. The question is how we can temper heuristics with de-biasing strategies so that a more calibrated and balanced diagnostic decision could be made. Such de-biasing strategies are often called cognitive forcing strategies. These are deliberate, systematic self-regulatory cognitive mechanisms to provide a check and balance to minimize biases.
One form of cognitive forcing strategy often used is known as the metacognition. It describes an individual’s ability to stand apart from his own thinking in order to be aware of his own preferred learning approaches and ultimately to manipulate his own cognitive processes to his own advantages. In short, metacognition is “thinking about thinking.” It allows one to ask questions like: “How well did I do?” “What could I have done it differently if I am given a chance again?”, etc.Therefore, making a timely, well-calibrated decision in an emergency situation is a critical thinking skill that should be inculcated in every physician. In fact, critical thinking in emergency medicine is defined as “the intellectually disciplined process of actively and skillfully conceptualizing, applying, analyzing, synthesizing, and/or evaluating information gathered from, or generated by, observation, experience, reflection, reasoning or communication, as a guide to belief or action” (Croskerry et al, 2009).
It is often assumed that every medical student would have developed this critical thinking skill by the time they have graduated from medical schools and would continue to further mature their cognitive process when they start working. After all, university graduates are expected to have a scholarly attitude towards knowledge and university is expected to be more than just a center for knowledge transmission (Biggs & Tang, 2007).
Unfortunately, within the specific context of undergraduate medical curriculum, the expectation that medical students will eventually develop matured critical thinking skill is largely empirical and yet to be explored or formally studied.
Furthermore, studies done in other field of tertiary education show potential cultural influence on critical thinking skill acquisition among undergraduate students. In fact, these differences have led to discussions and debates about the appropriateness of applying Western pedagogy for Asian students.
From some of these studies, it was shown that Asian university students are less likely to engage in critical thinking compared to their Western counterparts. In many Asian countries, the teaching and learning activities are often exam-driven in large-sized classrooms and structured around the goal of succeeding in examinations (Biggs & Watkins, 2001). Furthermore, Asian learners are usually perceived as silent, passive, uncritical and compliant rote-learners who rely on memorization (Biggs and Watkins, 1996); although paradoxically, despite of this rote-based learning strategy, Asian learners have often been found to outperform their Western counterparts (Biggs and Watkins, 2001).
Even within Malaysia, our tertiary students are found to be rather reserved about voicing their own opinions. One of these culturally influenced perceptual learning styles is their preference to be neutral, to “save face” as well as to adopt a conservative rather than confrontational approach (Yong, 2010).
The questions therefore are:
What is the preferred learning style of our medical students – passive rote learning or active engagement in discussion and challenges? And is this preference culturally influenced?Professor Croskerry has written a substantial number of articles and books on these topics. Click here to download an article by Prof Croskerry.
Does this pedagogy preference translate into the way our house officers deal with their seniors with they have a different opinion compared to their seniors? Do they passively comply with following orders or do they actively engage in discussion with them?
How does that affect our house officers when they face with a decision-making situation in clinical emergencies? Do they passively leave the decision to their seniors? What is their risk preference – they do prefer to choose a riskier alternative to “do something for the patient” (much like a gambling paradigm) or do they rather choose a more conservative approach of “wait and see”?
Do our house officers, therefore, perceive a chasm in the acquisition of the decision-making skill in clinical emergencies during their transition from being a student in medical school to being a newly qualified doctor? In other words, do they perceive that their medical schools do not prepare them enough for critical thinking and decision-making skills?
References:
Biggs, J. B. & Watkins, D. A. (1996) In Asian Contributions to Cross-Cultural Psychology (Eds, Paudey, J., Sinha, D. and Bhawuk, D. P.) Sage Publication, New Delhi.
Biggs, J. B. & Watkins, D. A. (2001) In Teaching the Chinese Learner: Psychological and Pedagogical Perspectives(Eds, Watkins, D. A. and Biggs, J. B.) Comparative Education Research Centre, the University of Hong Kong, Hong Kong, China, pp. 277-300.
Biggs, J. B., & Tang, C. (2007). Teaching for Quality Learning at University: What the Students Does (3rd ed.). New York, NY: Open University Press.
Croskerry, P. (2009). A universal model of diagnostic reasoning. Acad Med, 84(8), 1022-8.
Croskerry, P., Cosby, K., Schenkel, S. M. & Wears, R. L. (2009) Patient Safety in Emergency Medicine, Wolters Kluwer Health/Lippincott Williams & Wilkins, Philadelphia.
Yong, F. L. (2010). A Study on the Cultural Values, Perceptual Learning Styles, and Attitudes Toward Oracy Skills of Malaysian Tertiary Students. Europ. J. Soc. Sci., 13, 478-92.
Monday, January 11, 2010
CME Final Year Medical Students
Note:
Often my students have asked me what to present for this topic tutorial. I have revised, updated and included a few different links for you to prepare for this presentation.
Objective of this CME topic:
To give students a basic understanding on:
- the definition of pain as defined by the International Association for the Study of Pain (IASP).
(Click here for a list of definitions by IASP).
- the importance of pain management in emergency cases
- the different types of pain management modalities including pharmacological and non-pharmacological measures
- the physiological and psychological effects of pain
- the differences between analgesia and anaesthesia
- the different types of opioids used in emergency department including full agonists and partial agonists
- the different types of sedatives used in emergency department
- the different types of muscle relaxants used in emergency department
Topics for discussion:
TOPIC #1: Pain - In General
Definition by IASP
The importance of pain management in emergency cases
Physiological and psychological effects of pain
The WHO Pain Relief Ladder (click here for a description)
A general overview of the different modalities of pain treatment, divided according to pharmacological and non-pharmacological methods
TOPIC #2: Opioids
Discuss on the pharmacodynamics and pharmacokinetics of these common opioids used:
- Morphine
- Pethidine
- Fentanyl
Click here for the Merck Manual online.
TOPIC #3: Sedative Agents
Discuss on the concept of dissociative anaesthesia
Discuss on the pharmacology of
- Ketamine
- Propofol
- Etomidate
- Midazolam (as a prototype for benzodiazepine)
Know when to use which drugs under the different circumstances
Click here for the Wikipedia Portal Pharmacy and Pharmacology
Click here for the Virtual Anaesthesia Textbook online.
TOPIC #4: Muscle Relaxants
Discuss on the two classes of muscle relaxants - depolarizing and non-depolarizing and the differerences between these two in terms of mechanisms of action, and their basic pharmacodynamic and pharmacokinetics
Discuss pharmacodynamics and pharmacokinetics, and including side effects on
- succinylcholine
- atracurium and the concept of Hofmann elimination
- rocuronium and why it can be used for rapid sequence intubation in emergency department
- vecuronium and the importance of its cardio-stability properties.
- pancuronium - and its vagolytic effects.
Click here for comprehensive resource on rocuronium
Tuesday, November 13, 2007
Gastrointesntinal Emergencies - A guide for medical students
Key Points
A. Relation between abdominal Pain and Vomiting
Generally,
Pain → vomiting = surgical process
Example:
Epigastric pain that is relieved by vomiting suggests intragastric pathology or gastric outlet obstruction
Vomiting → pain = nonsurgical condition
However, this is just a guide, not a rule
B. Pain out of proportion
If patient complained of severe abdominal pain but you find relatively void of physicial findings (“pain out of proportion”) – especially in the elderly, with risk factors like atherosclerotic disease, atrial fibrillation, coronary heart disease, must think of mesenteric ischemia.
C. Duration of pain
Does The Duration Of Abdominal Pain Help In Categorizing Cause?
- Severe abdominal pain that persists for 6 or more hours is likely to be caused by surgically processes.
- Patients with pain of more than 48 hours' duration have a significantly lower incidence of surgical disease than do patients with pain of shorter duration.
D. Pitfalls In Evaluating Elderly Patients With Acute Abdominal Pain
Advanced age - blunt manifestations of acute abdomen
- Pain - less severe
- Fever - less pronounced
- Signs of peritoneal inflammation - diminished or absent
- Elevation of the white blood cell (WBC) count - less sensitive.
Examination
A. Tests For Peritoneal Irritation
Rebound tenderness
Cough test
Heel-drop jarring (Markle) test
- Highly sensitive test for peritoneal irritation
- Patient asked to stand, rise up on tiptoe with knees straight, and forcibly drop down on both heels with an audible thump.
- Among patients with appendicitis, 74% sensitive, compared with 64% for the standard rebound test
o Markle GB: Heel-drop jarring test for appendicitis [letter]. Arch Surg 120:243, 1985.
Obstipation
What is the significance?
Obstipation - the inability to pass either stool or flatus for more than 8 hours despite a perceived need is highly suggestive of intestinal obstruction
Can we give opioids in acute abdomen witb uncertain cause?
- For fear of masking vital symptoms or physical findings, old, conventional surgical wisdom proscribes the use of narcotic analgesics until a firm diagnosis is established.
- Increasingly, however, studies have demonstrated that pain medication may be given to selected patients with stable vital signs because the analgesic effect may be reversed readily at any time by the administration of naloxone.
§ Pace and Burke, in a prospective, double-blind study of 71 patients with acute abdominal pain, found that pain control with morphine had no deleterious effect on preoperative diagnostic accuracy.
- Although inconclusive, a growing body of data suggests that evaluation of acute abdominal disease may be facilitated when severe pain has been controlled and the patient can cooperate more fully.
§ McHale PM, LoVecchio F: Narcotic analgesia in the acute abdomen-A review of prospective trials. Eur J Emerg Med 8:131-136, 2001.
§ Pace S, Burke TF: Intravenous morphine for early pain relief in patients with acute abdominal pain. Acad Emerg Med 3:1086-1092, 1996.
Plain X-ray Films Useful?
Plain films of the abdomen have the highest yield when used in the evaluation of patients with suspected bowel obstruction, intussusception, ileus, and free air secondary to a perforated viscus.
They have much less utility in detecting intraabdominal mass, renal calculi, diverticulitis, gallbladder disease, and abdominal aortic aneurysms
The supine view of the abdomen is the most informative and worthwhile abdominal film. The upright film is superior for visualizing air-fluid levels associated with ileus, obstruction, or biliary air.
The erect chest radiograph is most sensitive for detection of free intraperitoneal air and may show basal pneumonia, ruptured esophagus, elevated hemidiaphragm, air-fluid levels associated with subdiaphragmatic or hepatic abscess, pleural effusion, and pneumothorax.
Air Fluid Pockets
Are air-fluid pocketss within the intestine always abnormal? No
1. The number of pockets:
A study of 300 normal patients by Gammill and Nice shows that although the average number of air-fluid levels was four per patient, some have up to 20 air fluid pockets.
(To remember: if >3, consider might be abnormal (although as said above, it can be up to 20!)
2. The size of pockets
Although typically less than 2.5 cm in length, some were 10 cm.
Easy to remember:
Consider abnormal if (remember 3,6,9):
In Small bowels >3 cm
In Large bowerls >6 cm
In caecum >9cm
Remember the number 3 for small bowels:
>3 cm dilatation
> 3 air pockets
> 3 mm wall thickness
To know more about Markle test and cough sign: click: http://www.postgradmed.com/pearls.htm
http://www.fleshandbones.com/readingroom/pdf/233.pdf
To know more about the dilemma in diagnosing causes of acute abdomen in emergency department, click here:
http://www.emedmag.com/html/pre/cov/covers/011502.asp
Two excellent articles in Student BMJ:
1. on acute abdomen, click here:
http://student.bmj.com/issues/00/03/education/56.ph
2. on abdominal radiograph, click here to download a series of articles in pdf:
To download a FREE powerpoint presentation on acute abdomen, click here:
http://www.edu.rcsed.ac.uk/pps/pps83.pps
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