Week 10

Reflection:

Using the Gibb’s Reflective Model I will reflect on the ninth Lab session we had for this semester. It took place on the 4th and 5th of November.

Description: This week we solved the IV therapy workbook and spent the first hour learning about how to perform an aseptic technique when handling needles and equipment, how to insert an IV cannula, calculate the drip rate, set up an IV set, connect it to an extension, connect the IV line to a IV bag and prime the IV line. For this part of the session I understood where everything went and how it all worked. I was also able to correctly calculate the drip rate. Also, my teacher showed me how to improvise by hanging the IV fluid on a spine board to free my hands. In the second hour, we practiced the approach to a cardiac patient. I went first and my patient was diaphoretic and had difficulty breathing. I had good communication with the patient, remembered to do an ECG this time, gathered the history appropriately, and performed the VSS. However, after I found out the patient had dyspnea it took me a few minutes before I auscultated her chest. Moreover, I saw her SpO₂ was 89% so I decided to give her oxygen.  When I provided her with oxygen, I used a nebulizer mask instead of a non-rebreather mask. This was a terrible mistake. However, my teacher notified me of my mistake and I fixed it. A while after I put the  non-rebreather mask on the pt., her SpO₂ went up to 96% and I instantly, without thinking, removed the mask, only to put it back on a few minutes later when the SpO₂ dropped. After that I discovered the patient was diabetic, however, it slipped my mind to take a BGL measurement and also that diabetic pts. usually present with no chest pain during an MI. The patient’s ECG rhythm was sinus tachycardia, and I said I would perform a 12-lead ECG to check for a possible infarction that wasn’t visible on a 3-lead.

 In the next session, we further practiced IV cannulation and setting up an IV line. After that we performed another cardiac patient scenario. My patient presented with severe chest pain and difficulty breathing. He was tahcycardiac and hypertensive and his ECG rhythm was sinus tachycardia. I took all the history using PQRST and SAMPLE and performed a thorough VSS. This time I used a non-rebreather mask to deliver oxygen to the pt. As the scenario progressed the pt.’s rhythm suddenly became an ST elevation. I decided to provide morphine, nitrates, aspirin, and continue oxygen administration. My teacher later remarked I could have also prepared double cannulas to prepare for any possible upcoming emergency.

Feelings: At the beginning of the first session I felt really excited to learn about the preparation process of IV equipment. Later on, right before I started the scenario, I felt confident, but that changed really quickly. As I progressed through the scenario I made multiple mistakes and I didn’t feel very confident and felt lost and confused. My systematic approach was all jumbled up in my head and I was struggling to fully understand the scenario. By the end of that session I felt upset at myself for messing up so bad.

In the second session, for the IV practice I felt at ease and capable, since I understood everything the day before. After that, when we were practicing a cardiac patient scenario, I felt nervous at the start. However, I stuck to the systematic approach this time and managed the scenario well. This made me feel so good and when my teacher said I did very well, I felt much more confident. 

Evaluation: Learning about IV preparation was a really good experience, since I understood everything involved in the process. Also, it was great to be able to practice this skill individually. This made me more aware of every step of the process, which helped me understand everything. I would say the scenario in the first session was a bad experience, however, without it I don’t think I would have been able to do as well the next session. It was good to make all those mistakes because it was like a wakeup call for me to step up my game. This made my experience in the second session so much better. Also, being able to know my mistakes the first time and fixing them in the next session was a really good learning experience for me.

Analysis: My mistakes in the first scenario were due to a lack of organization of my thoughts. I didn’t follow a systematic and logical approach and that lead to me missing out crucial steps. For example,   BGL measurement for the diabetic patient is something I know. However, I didn’t preplan my approach or think logically about the scenario, and that lead to me missing that important assessment. Also, now I realize that if I start a scenario without a set plan I am bound to forget things and end up confused. In the second session I revised my approach and that was the key to me performing much better.

Conclusion: I could have been more focused and thoughtful of what was unfolding throughout the scenario. Also, I should have revised the steps for approaching the cardiac patient beforehand. This could have lead me to assess the patient appropriately and not forget anything.

Action Plan: My plan is to revise the OSCE marking sheet for approaching the cardiac patient. This is in order for me to be able to have a pitch perfect and systematic approach, and to stop me from forgetting anything. Moreover, I will look through the OSCE sheet for IV preparation and practice drug calculations. That is to be prepared for the next session, in which we will be preparing an IV set and calculating and counting the drip rate.

Picture 1: Calculation of the drip rate

Picture 2: IV cannula inserted and IV set primed

Picture 3: IV fluid hung on a spine board to improvise

Picture 4: IV chamber with set drip rate

Domain Knowledge:

This week we took about pacemakers. Sick sinus syndrome is the general term for a group of dysrhythmmias caused by the malfunction of the sinus node. Most commonly caused by ischemic heart disease. In this case the patient must be paced using a pacemaker. A pacemaker can be external, tansvenous or implantable. On an ECG its very obvious. 

Picture 5: ECG with a pacemaker

Transvenous pacing is done in the ED in hospital. It when an electrode is advanced under fluoroscopy to place the electrode. This is temporary. For implantable pacemakers there are two. fixed rate and demand. Demand is usually used and it senses the patient's intrinsic rate, specifically the QRS complex, and will only fire when the intrinsic rate falls below a set rate. Fixed rate fires at a constant rate regardless of the patient's intrinsic rate. 

Pacemakers can be atrial, ventricular, or for both (dual chamber). A patient is usually given Aspirin after this to avoid blood from coagulating on the wires of the pacemaker. Pacemakers can also sense the RR and blood pH.

Problems faced by a pacemaker are failure to sense, capture, and pace. Failure to sense in from the pacemaker's failure to sense the heart's intrinsic electrical activity. It generates a pacing spike at inappropriate times. This is very dangerous and could lead to the RonT phenomenon. Failure to capture is when the paced stimulus does not result in myocardial depolarization. The pacemaker spikes are not followed by a P wave or QRS complex. Most likely cause is that the output current of the pacemaker is too low. Failure to sense and capture can occur in the same patient. Failure to pace means the pacemaker is doing nothing. If a patient with a ventricular pacemaker has a STEMI, they cannot be diagnosed from an ECG, they are diagnosed by their history and inhospital ultrasound.

Pacemakers can be placed in both ventricles (biventricular pacing) and this is called cardiac resynchronisation therapy (CRT).

Some indications for implanting a pacemaker in a patient are:

• The patient has had a past episode of VF or VT arrest
• had at least one episode of VT
• had a previous heart attack and an increased risk for sudden cardiac arrest or death
• hypertrophic cardiomyopathy

Implantable defibrillators have an energy level of 35-40J. Low compared with surface defibb, cause surface defibb must go through all layers of the thorax before reaching the heart. Thus needing a high level of energy. But the implantable one is directly on the heart. It's leads are biphasic and for cardioversion the energy can be as low as 2J. 

Enquiry and Research: 

Pacemakers consist of a controller pack that contains the battery and programmable hardware and wire electrodes that are attached to the heart chambers that need to be stimulated (Wesley,2011).

Pacemakers have two functions: to sense the atrial and/or ventricular electrical activity and the second is to pace, during which the electrode generates and electrical discharge to depolarize the myocardium. The timing cycle consists of a lower rate limit (LR) and a ventricular refractory period. If an intrinsic QRS complex occurs the LR time is started from that point. If there is no QRS and the LR is reached the pacemaker will spike.

Picture 6: Table of the pacemaker codes. Adopted from (Wesley,2011)

Letters 1,2,3 are the most commonly used letters and provide sufficient information about how the pacemaker functions, helping in the interpretation of the associated ECG rhythm.

Implantable cardioverter defibrillator therapy (ICD) involves the internal placement of a device capable of delivering electrical shocks to the heart to terminate life threatening rhythms, such as VT and VF. Like the pacemaker except instead of a simple electrode in the rt ventricle, there is a special electrode touching more surface area of the endocardium. This electrode delivers the life-saving shock to the heart in the event of lethal ventricular dysrhythmmias. It can deliver anitachycardia pacing and cardioversion shocks for VT and defibrillation shocks for VF (Wesley, 2011).

Picture 7: Reading from (Wesley, 2011).

Picture 8: Readings from (Wesley, 2011)

When ICDs are delivering shocks inappropriately, they can be disabled using a ring magnet. This magnet can temporarily disable the shock capability of an ICD. However, the magnet does not disable the pacing capability for treating bradycardia.The ECG rhythm must be monitored at all times  when the ICD is disabled. These magnets are usually supplied by the manufacturers (JRCALC, 2013).

A really good illustration of the pacemaker in the heart is found on the following link (AHA, 2015). The one in the illustration is a ventricular pacemaker. The link is: http://watchlearnlive.heart.org/CVML_Player.php?moduleSelect=pacmkr

This illustration helped me visualize the effect of the pacemaker on the heart.

References

American Heart Association. (2015). Pacemaker [Video illustration]. USA: Watch, Learn, and Live Interactive Cardiovascular Library.
Joint Royal Colleges Ambulance Liaison Committee. (2013). UK ambulance services: Clinical practice guidelines 2013. Bridgwater, England: Class Professional Publishing.

Wesley, K. (2011). Huszar's basic dysrythmias and acute coronary syndromes: Interpretation and management (4th ed.). St Louis, MO: Elsevier.