MCQ and OSCE Group 6 Year 5 Medical Students 2009-10

UPDATED 24 SEPTEMBER 2009

Group 6 Final Year Medical Student Emergency Medicine Posting
Lecturer Co-ordinator: Dr. Chew Keng Sheng

Results of written exam:

Matric No	MCQ Grade	OSCE Grade
85192 85268 85190 85228 85284 85247 85333 85258 85319 85185 85202 85234 85174 85371 85219 85279 85338 85347 85353 85183 85344 85335 85225 85197 85339 85352 85351	Distinction Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail	Pass Pass Pass Pass Distinction Pass Pass Pass Pass Distinction Pass Distinction Pass Pass Pass Pass Pass Pass Distinction Pass Pass Pass Pass Pass Distinction Pass Distinction

Note to Group 6: Please check your grade as soon as possible. I will delete off your matric no after a week and replace it with Student A, B, C...etc to protect your identification from your friends from other groups! A copy of the results will be posted at the A&E notice board.

Comments on the OSCE exam:
Most students fared worse than I have expected:

Question 1:
The X-ray shows an obvious pneumothorax on the right lung with a very large area of lucency (extending at least over the entire peripheral one third of the right lung) devoid of any lung markings. I am so surprised that many students did not answer at all on the pneumothorax.

Instead many students wrote the answered about hemothorax over the left lung. While it may seems that the haziness over the left lung may give the picture of hemothorax, the question is about a non-trauma condition with progressive shortness of breath.

Furthermore, the haziness shown over the left lung field is heterogenous with the appearance of a fibrotic lung. (Click here for a description and a list of etiology of hemothorax and see below for the linked image of hemothorax from emedicine.com). This patient in actual case has a past history of tuberculosis and COPD with fibrosis and bronchietasis. The pneumothorax was likely due to a ruptured large bulla.

Image URL:
http://img.medscape.com/pi/emed/ckb/thoracic_surgery/424545-425518-718.jpg
Click here to go to the original article in Medscape on hemothorax.

Unlike the image shown here (which is a hemothorax), the costophrenic angle of the image in the OSCE question was not obliterated yet many students answered obliteration of costophrenic angle as a feature. (Note: As much as 400-500 mL of blood is required to obliterate the costophrenic angle as seen on an upright chest radiograph). Furthermore, there was no meniscus sign in that question image (unlike the image here). Another common answer given by the student was pleural effusion.

Section 3 on the pathophysiology follows section 2. If the students answered section 2 wrongly, naturally the explanation he/she gave for section 3 would be wrong. Only a few students answered section 2 and 3 correctly: the positive intrathoracic pressure reduce pre-load and as it impinges on the heart, it causes impaired cardiac contractility. Looking at the clinical picture of that patient, most likely the pneumothorax is "tension". Here many students did not dare to put the answer "tension pneumothorax" probably because the picture does not show mediastinal shift to the contralateral side and the students must have thought that tension pneumothorax must have classical signs typical of tension pneumothorax as taught in textbooks. This happens when the focus of students was oriented towards "managing the X-ray" rather than managing the patient.

A side note: another radiographic feature of pneumothorax is "deep sulcus sign". This is not commonly taught in many textbooks. Deep sulcus sign can be seen on supine films.
Download an article on deep sulcus sign here.

Deep sulcus sign happens when in supine position, the air collects laterally rather than medially, and therefore, it abnormally deepens the lateral costophrenic angle thus producing the appearance of a deep sulcus.

Section 4: surprisingly although they may have gotten wrong in the previous two sections, all students answered correctly that the one specific emergency procedure to be performed is chest tube insertion after needle decompression.

Question 2:
Basically most students (almost all) did very well in this orthopedic question on pelvic fracture - multiple fractures, open book type involving both superior and inferior rami as well as other areas fractured. Syabas! probably since they have just finished their ortho posting prior to coming to A&E.

Question 3:
The question on AED was basically moderately well done. Probably most students forgot AED uses pads, not paddles. Many students answered the precautions as the way the paddles are handled, checking rhythm again before pressing shock button, etc, etc. AED uses pads - just stick the pads on the chest wall appropriately, ensure a good seal of the pads to the skin and obey the voice prompt. One of the basic precaution is to check for any signs of life - (to ensure that the patient is in cardiac arrest/without signs of life/pulseless). This may seems to be funny, but emedicine.com describes of an incident where the EMT student that jokingly placed an AED on a classmate that still had a pulse (click here). Referring to that incident, emedicine.com also reported that most states in US have passed a liability waiver for bystanders who use an AED to assist an unconscious patient although negligent use of an AED can result in involuntary manslaughter charges. I wonder whether similar law could be or have been passed in Malaysia for any of our Malaysian public to use AED. Should any untoward happenings occur, is the public protected?

I have re-published a free article (here or here) on precautions of using AED from content4reprint.com.

Question 4:
This question on a penetrating intra-abdominal injury with a stabbed knife in-site is supposed to be a very easy question. Most students did well; however, most students when asked in section 3 on the initial management of such patient in the emergency department just "regurgitated" the initial approach to trauma including "DR ABC", primary survey, secondary survey without any reference as to how to manage the stabbed wound. This shows that the students do not think first; rather, they "regurgitated" out the facts as much as they could and as much as they have stored in their brains (I was puzzled as to why "danger" component also comes into place, since the question ask on management in emergency department, on at site of incident or field management/pre-hospital management). A previous blog post on the exact case can be found here.


Top Ten Precautions in Using Automated External Defibrillators (AED)

The precaution and proper use of defibrillators is one important chapter, and it is included in the standardized curriculum of the AED basic training course . The American Heart Association, the American Red Cross and the National Safety Council approved and published these precautions for the safety of both the patient and the user of the AED. After the occurrence of the incident you have to look for an AED emergency kit right away.

It is likely that you will find one at the building entrance if you are in a public place or building, because this is the standard place for these kits. Make sure you are familiarized with the contents of the kit. You'll probably find two pads, a CPR barrier mask, a piece of cloth or a towel, scissors, a pair of gloves and possibly a razor. So go though these automated external defibrillator precautions in order to avoid other accidents from happening.

1. First of all, check the patient for pulse. If you cannot sense the pulse you may proceed, and let the AED determine if there are heartbeats at all. In most of the cases the AED will indicate if there is a pulse and if defibrillation is needed.

2. You might want to try to perform a cardiopulmonary resuscitation (CPR) before taking any further action. But make sure that the AED device is not analyzing the rhythm. This may cause some unpleasant accidents. Many AED devices possess motion and CPR detector, but you won't have time to determine that in a crisis. (My comment: This is in line with the AHA 2005 guidelines on CPR first rather than shock first for non-witnessed out-of-hospital cardiac arrest cases)

3. The AED device should be used with great care if the patient is in a moving means of transportation. The movement of a vehicle may affect the analysis the AED makes, which won't be accurate and consequently it will perform incorrect tasks.

However, if employed while transporting the patient to hospital, stop and take the pulse several times and do monitoring checks with the help of the AED. Some AED models are smart enough to distinguish between external movement and cardiac movement.

4. Beware of water!

Before performing the defibrillation, make sure the chest of the patient is completely dry. In the AED kit you will find a piece of cloth or a towel that is set there exactly with the purpose of drying the patient's chest. Sweat or water spots make certain parts of the chest be less resistant and the defibrillation might not be very effective. Besides, the presence of water may lead to local burns. Also make sure that the patient has no contact with water. It the patient is in a pool or outside, in wet weather, take the patient under a safe shelter and dry the chest before taking any further action.

However, do not use alcohol to dry the chest of the patient. As you may probably know, alcohol is very flammable.

5. Take a close look at the patient's chest. It should be free of nitroglycerine patches or any other patches or materials. Get rid of any patches before performing the defibrillation. The nitroglycerine patches may cause explosion when in contact with the AED pads.

6. Make sure the patient does not lie on a conductive surface like sheet metal or metal bleachers. These conductors may transmit the shock to other people that are in the patient's neighborhood.

7. Keep your hands off the patient while performing the defibrillation.

Also make sure no-one else touches the patient. If these rules are not respected, you or others might get the electric shock. Touching the patient while the AED performs the analysis will not give accurate results.

8. An AED should not be used on children under the age of 8, or under 55 pounds.

Some AEDs are not able to adjust to the low-energy settings that are required for children. Anyway, there are several AED devices on the market that may resuscitate even children under 8. So check the packaging of the device before using it.

9. Take a look at the environment where you will perform the resuscitation!

You shouldn't perform a defibrillation if you are among flammable supplies such as gasoline or free-flowing oxygen. Also, the AED should be used with prudence when there is strong electromagnetic interference (EMI). The AED might detect false cardiac rhythm when there is electromagnetic interference.

10. Careful with the cell phones and portable radios- the waves cause trouble!

It is highly important to notify an ambulance of the incident and the cell phone is the most effective device, but make sure you keep all cell phones at least 6 feet away from the patient and the AED. The cell phone may influence the analysis. Radios have the same effect on the AED, so keep all radios away.