This blog will not to teach you how to become proficient in echocardiography, you know yourself that takes years of practice and expertise. What I want to show you is that you can acquire good basic echocardiography skills in a relatively short time frame. I hope that by sharing my beginner's struggles, misdiagnoses and highlights you will see how it is achievable. Most importantly, I hope it shows you that you can have fun learning echo...
If you’re reading this there is a high chance you want to learn critical care echocardiography. The great news is that you’re a third of the way there; the two remaining things you need are perseverance and patience. There has to be an acronym somewhere? Yes! Key ingredients for learning Echo: PPE (Perseverance, Patience and Enthusiasm) and occasionally Personal Protective Equipment (this is to protect you from the nurses if you don’t clear your mess away).
Thanks for reading and I hope it’s useful.
Before you pick up a probe…
I attended a locally run 1-day taster course followed by a formal Rapid Assessment Cardiac Echo (RACE) course. I would recommend attending something similar, it allows you to set strong foundations and means you’re less likely to start off with bad habits. We recapped the physics of ultrasound (of course I remembered it all and didn’t fall asleep :-)), how to obtain good acoustic windows and what basic questions to answer with a RACE study. I was pleased to discover that I only needed to know 3 basic position points.
Sounds pretty easy right: 1,2,3? Because I was super keen I nose dived into scanning my first patient. There were a few things I didn’t do, which in retrospect would have made my first scan a whole lot easier.
I would have liked to round this off with tip number 5 but I couldn’t think of more than 4 :-)
Ready to pick up the probe?… Lets see my first scan!
I’m purposefully not going into details of how to obtain the views because there are so many great educational resources out there already. I really like the 15 minute video by ultrasound village which can be found using this link: http://ultrasoundvillage.com/educationresources/modules/lectures/?lecture=19.
Under the Echo Education tab on this website (link) you will find some of the best resources around. If you haven’t already checked out the Intensive Care Network’s echo section then now would be a good time.
You'll pick up the textbook rules in no time. What I want to show you is the reality of trying to get the images and the common pitfalls when you first start scanning. I made all the textbook mistakes…
My first PLAX
Can you see why this image is poor?
What I did wrong:
I held the probe too laterally from the sternal edge and I didn’t move up and down the ribs spaces to achieve the best possible image. To avoid my mistakes start medially, hugging the left sternal edge. If you’re still not getting a view then move laterally.
If the patient has hyperinflated lungs as in emphysema or on a ventilator you may find you need to move down a few rib spaces- from the 3rd to 5th intercostal space for example.
This image below is my 12th PLAX that shows both pericardial and pleural fluid (above and below the descending aorta respectively).
To recap, a good PLAX image should fulfil the following 3 criteria:
This image below happens to be my 9th RACE scan and is a better representation of a good PLAX; you can see it more or less fulfills the 3 criteria for a good PLAX ( apart from depth optimisation).
My first PSAX at mitral valve level
What I did wrong:
I didn’t optimise depth or gain. Can you see the larger dot on the right side of the image- this is the focal point- it should have been further down at the level of the mitral valve, optimizing the focal point will improve the lateral resolution. What I did achieve with this image is the round ‘doughnut shape’ of the LV.
My first A4C
What I did wrong:
This A4C makes the heart look like a football (soccer ball if you’re Australian) and we all know we are looking for that nice rugby ball shape. The image is off centre, making the heart look tilted. The interventricular septum should be in the centre of the screen, with apex of the heart pointing towards the transducer. I could have achieved this by ‘tilting’ the tail of the probe.
The image below is my 30th RACE study A4C. As you can see it looks more rugby ball shaped and the apex of the heart is pointing toward the transducer. I did this by moving down a rib space until I achieved the image I wanted. It appears over gained, which makes the structures look too bright, but I hope you can see the improvement?
You can perform apical 5 chamber and apical 2 chamber views here- I will let you look up how to obtain these views and what information they add to your RACE study.
SUBCOSTAL view… Ok, maybe not!
Having discussed with a few experts I was reassured it wasn’t unusual to have difficulty obtaining a SC view, but occasionally it is all you can get in a ventilated patient. Essentially there is no way of predicting who will have a good subcostal view, which I think adds to the challenge and fun! I was pleased to see that my next scan yielded a better result:
Rotating to the IVC...
Remember you get the IVC view by rotating the probe 90 degrees anti-clockwise. If you are going to measure the IVC the American Society of Echocardiography (ASE) recommend you do this 0.5-3.0cm from the ostium of the right atrium. When you do further reading you will discover there are lots of different opinions regarding measurement of the IVC (and even its validity)…
Struggling to get the images? Think about echo simulation!
If like me you still struggle to have a 3-dimenional mental construct using 2 dimensional images there are a few things you can do. The best thing you can do is check out Sam Orde’s RACE video on an echo simulator (link)
I think the appearance of cardiac anatomy on ultrasound can sometimes be confusing. The echo simulator allows you to see the sonographic shapes and patterns displayed in 2 dimensions and relate that to the 3 dimensional configuration. You will learn to appreciate what probe movements you have to make to correct your mistakes. If you have the opportunity I would recommend utilising simulation. If you haven’t got a simulator there are some good iphone and android apps to allow you to do this.
The universe must have sensed my disappointment...
For my 5th scan I was handed every beginners dream. To cut a long story short, I will go straight to the good stuff…
72 yr old female post permanent pacemaker insertion. A medical emergency call was triggered at midnight for hypotension and tachycardia; SBP 60mmHg; HR 145bpm. As an extension of the ‘Circulation’ assessment I performed a bedside RACE looking for some important causes of circulatory shock. Given that she had recently had a pacemaker inserted my thoughts were: is this cardiac tamponade? Using RACE I could also look at other important differential diagnoses including hypovolaemic or cardiogenic shock. Isn’t it great that you can begin to rule out causes of undifferentiated shock with a simple, non-invasive ‘bedside test’?
Subcostal (SC) view
In this image you can’t particularly appreciate the pericardial fluid- but remember in tamponade the actual volume of pericardial fluid can be small, it is all about the intrapericardial pressure (IPP). A small volume of fluid accumulation in a short time frame can lead to an acute rise in IPP > RV filling pressure and consequently lead to the clinical and echo manifestations of cardiac tamponade.
It may be difficult to appreciate in a single picture but can you see the scalloped appearance of the RV, with the black echogenic structure (blood) above it? This is RV diastolic collapse, compromising RV filling and leading to this patient’s haemodynamic compromise.
The RACE signs of cardiac tamponade I was looking for were:
Another important structure to assess in tamponade is the IVC. In tamponade, as you know, the right atrial pressure is high and in a spontaneously breathing patient the IVC size and its variation with respiration reflects RAP pressure (with the usual caveats). In true cardiac tamponade (as opposed to low pressure tamponade) the IVC will be:
IVC view- fixed dilated IVC in cardiac tamponade
We all need an easy aid memoire at 2am so I remember the IVC findings by thinking of a fixed and dilated pupil…
At this point I would recommend looking at other learning resources to consolidate what a true cardiac tamponade looks like, the university of Stanford has a good one: https://web.stanford.edu/group/ccm_echocardio/cgi-bin/mediawiki/index.php/Tamponade#Diastolic_RA_and_RV_collapse
The important thing about this case is that by performing a RACE I was able to gain vital information in a short time frame to confirm what I thought clinically. It is important to emphasise that tamponade is always a clinical diagnosis but the echo findings enabled me to be more confident with the diagnosis and think quickly about the appropriate management steps.
Within 30 minutes of calling my senior registrar I helped him place a pericardial drain that can be seen below. The crowd cheered and we were hailed heroes (not quite, but we did get Haribo jellies from the nursing staff)
On review of the patient the next morning she was sat doing a crossword… Hoorah.
Beware of overconfidence…
My confidence was at an all time high. For my next scan I was faced with a young woman day 4 post adrenalectomy with sudden onset tachypnea and hypoxia who was normotensive. What I thought I saw was a dilated, hypokinetic right ventricle. The story fitted with pulmonary embolism and so I thought I was seeing acute RV pressure overload. I would recommend at this point looking at some online resources to recap the appearance of acute RV pressure overload.
The patient had a CTPA that showed left lingula consolidation as the cause for her respiratory distress. There was no PE. I had done what I had been warned about: overdiagnosing a PE.
A few scans later I scanned a patient with a dilated RV and a D-shaped septum- you can see this image below. I was very aware of my recent faux pas and cautiously showed it to my boss.
PSAX- D shaped septum and an enlarged RV
The patient had end stage COPD with chronic volume overload… Still no PE…
Using echo to guide fluid management? Its not so easy.. there are lots of pitfalls to be aware of...
Assessing fluid status in critically ill patients is notoriously one of the hardest things to do. However, if you are aware of the limitations and what they mean then you can combine your clinical assessment with basic echo findings to guide fluid administration.
This is my basic approach. If after taking a history and examination I think the patient is hypovolaemic and likely to be fluid responsive I will perform a RACE to ask the following binary questions (basic echo is not designed to ask or answer complex questions- and it would be dangerous to do so)
Signs on a RACE that may suggest the patient would deteriorate after a fluid bolus
You must understand the caveats to each of these questions as they can be affected by many different pathological states. For example, any cause of pulmonary hypertension or even mechanical ventilation can result in dilation of right heart chambers and a LBBB can cause paradoxical interventricular septal wall motion. I would recommend doing some extra reading around this as you are learning basic echo and always getting a second opinion (if time allows).
I put this simple approach into practice at a 2am medical emergency call for a 78 yr old male with hypotension, 70/40mmHg, on a background of ischaemic heart disease. Before the nurses gave the fluid bolus that was prescribed I performed a RACE.
A4C- dilated LV and LA
By answering the simple binary questions above I was able to add important information. The patient had a dilated LV with severely impaired contractility and a dilated IVC with no respiratory variation. Instead of getting a fluid bolus that would have very likely put him into acute pulmonary oedema he was commenced on inotropes.
I would recommend taking a multi faceted approach to learning echo- don’t forget to ask for help, echo enthusiasts are just as enthusiastic about teaching! I hope I have shown that even if you struggle at the beginning it will get better and that you can become competent in basic echo with just a little PPE! You can formalise your learning by completing a certification in basic echo such as the CCPU with the Australian Society of Ultrasound Medicine (ASUM) or FICE in the UK...
I think above all else I have developed a healthy respect for the limitations of basic echo and I am more aware of what it can and can't add to the management of critical care patients. My biggest tip would be to keep it simple, stick to the basics and do them well.
I hope you have picked up at least one ‘do’ and ‘don’t’ for when you begin your echo journey. Good luck, and have fun!
Hello, I’m Emma an anesthetic trainee from the UK. I’ve taken time out of my training programme to develop a greater understanding of intensive care medicine and during this time I have acquired a love for echo! (As well as the east coast beaches and inner west food scene). I wrote this educational resource mainly to show echo beginners that becoming competent in basic echo is definitely within your grasp...