Clinical Case: Pulmonary Embolus

A 65 year old gentleman presents to the emergency department complaining of sudden sharp chest pain, shortness of breath and lightheadedness.

His pulse is 110, his blood pressure his 90/50, and his oxygen saturations are 92% on 40% venturi mask. His JVP is elevated, but his physical exam is otherwise unremarkable.

You perform a bedside echo which reveals the following image:

This is an example of a pulmonary embolus (PE) leading to hemodynamic instability. Ultrasound has a role when the diagnosis of PE is suspected and the patient is too unstable to undergo a CT or V/Q scan.

The ultrasound image above is an apical view of the heart, with the ventricles at the top of the image and the right side of the heart on the left side of the screen. As you can see, the right ventricle (RV) is enlarged, and is larger than the left ventricle in this image. Also, there is hyperkinesis of the apex of the RV with akinesis of the mid free wall. This distinct pattern of RV dysfunction on ultrasound is typical in cases of PE and is known as McConnell's sign.

Procedure: Internal Jugular Central Line Insertion

One of the procedures where ultrasound is useful is for central line insertion into the jugular vein. In fact, ultrasound guidance for internal jugular line placement is considered standard of care.

The ultrasound portion of the technique begins at 3:43. You can use the transverse (at 5:00) or longitudinal view (at 5:05) to visualize the tip of the needle as it is inserted into the jugular vein.

When inserting the needle, you should assure the following:
- The internal jugular is centered on the ultrasound image
- The ultrasound probe is perpendicular to the needle's insertion angle is using the transverse view
- The needle's insertion point is at the middle of the ultrasound probe

As mentioned in the video, you should also confirm that the wire is correctly positioned in the jugular vein before proceeding with dilating.

Podcast Resource

Ultrasound Podcast is a great resource with podcasts that discuss the applications of bedside ultrasound. Their podcasts include recent trials as well as plenty of cases and ultrasound images. 

Upcoming conferences

Here is a list of upcoming ultrasound conferences:

- Point-of-Care and General Medicine Ultrasound in Portland, Oregon from July 23-24, 2016
- Canadian Resuscitative Ultrasound Course in London, Ontario from August 18-20, 2016
- Live Critical Care Ultrasound in Rosemont, Illinois from July 16-17, 2016
- Live Advanced Critical Care Ultrasound in Rosemont, Illinois on July 18, 2016

Click on the links above for information regarding each conference and registration.

Clinical Case: Takotsubo Cardiomyopathy

A 45-year-old lady presents to the emergency department after experiencing chest pain at her mother's funeral. An ECG performed reveals ST segment elevation in the V1-V4 leads. She undergoes emergency cardiac catheterization, but coronary arteries are normal.

A bedside echocardiogram performed after the procedure reveals the following images:

This case is an example of Takotsubo Cardiomyopathy, or "broken heart syndrome". It is an acute presentation of left ventricular systolic dysfunction that is very similar to myocardial infarction. Howeverm the dysfunction in Takotsubo Cardiomyopathy is not confined to one artery territory, nor is there any occlusive coronary artery disease found on cardiac catherterisation.

Generally, the systolic dysfunction affects the mid-apical portions of the left ventricle, causing the classic "apical ballooning pattern" as seen in the video above. The term "Takotsubo Cardiomyopathy" comes from this pattern seen on echography, which is similar to the Japanese octopus trap of the same name pictured below.

The first ultrasound image demonstrates the apical ballooning of the left ventricle. The second view demonstrates the difference in contractility of the apical and mid regions compared to the basal regions of the heart. As you can see, there is better contraction of the left ventricle in later images, which corresponds with the more basal regions of the heart.

Takotsubo Cardiomyopathy is a great example of how bedside ultrasound can be used to assist with the diagnosis of certain clinical entities.

Two great resources

Here are two websites with guidelines, resources and modules for ultrasound training.

The first is The American Institute of Ultrasound in Medicine's website, which includes physician training guidelines, official statements, ultrasound parameters as well as an ultrasound curriculum.

The second is the Society of Ultrasound in Medical Education's website. It includes a curriculum database of curricula from several different universities as well as learning modules that range from ultrasound theory to its application.

Both of these websites contain great resources for medical professionals at any level of ultrasound training looking to refine their skills, attend an upcoming ultrasound worksop/conference, teach ultrasound skills to learners, or develop an ultrasound curriculum for their institution.

Handheld Ultrasound

I had a few opportunities this week to use a handheld ultrasound while on call, and I was quite impressed with the experience. I was able to quickly assess volume status, gross cardiac function and rule out significant pleural effusions quickly and easily on a few of the patients that were admitted.

The handheld ultrasound is built for a busy clinical environment. Its relatively small size allowed for rapid access and use. The device functions were very intuitive, and I found I was able to use the colour functions and adjust the depth and gain easily. Although the screen is small, I found that the images captured were of good quality and aided me in my clinical diagnosis.

Although great for clinical use in urgent care settings, I do not think the handheld ultrasound is ideal for clinical teaching. The larger portable machines have a screen size that is more suitable for teaching small groups. Also, I feel that trainees may need to have a few sessions with larger ultrasound machines before attempting to capture images with a handheld device.

All in all, I was quite impressed with the handheld machine, and I would definitely use one again if it was available.

Critical Care Guidelines - Part 1

Part 1 of the Society of Critical Care Medicine Guidelines for Bedside Ultrasonography were published by Frankel et al. in November of 2015. These guidelines include recommendations on several non-cardiac applications of bedside ultrasonography in critically ill patients. In particular, there were strong recommendations for the use of ultrasound in procedures such as thoracentesis, paracentesis and central line insertion.

The written guidelines can be found here. There is also an iCritical Care Podcast by Dr. Ludwig Lin and Dr. Michael Blavais that comments on these guidelines, discusses the integration of technology into ultrasound application and practice, and provides suggestions for ultrasound training of learners and practicing physicians.

Part 2 of these guidelines, which includes the cardiac applications of bedside ultrasonography, have recently been published, and I will post the link once they are up on the Society of Critical Care Medicine's website.

Dalhousie Ultrasound Fundraiser

The Dalhousie Internal Medicine Residents are running in this year's Bluenose Marathon to fundraise for a new ultrasound machine for the Medical Teaching Unit at the Halifax Infirmary.

Information on their fundraising campaign can be found here.

Introduction

Point of care ultrasound (POCUS) is an emerging tool used at the bedside to evaluate patients in emergency departments, hospital departments, and intensive care units. The use of ultrasound guidance for certain clinical procedures has become the standard of care. This technology has the potential to aid in the diagnosis and management of patients as well as increase patient safety during bedside procedures.

This blog will serve as a resource for information on bedside ultrasound and its various applications. These resources will include society guidelines, review articles, clinical trials and published educational interventions. These resources will inform my reflections on how beside ultrasound has impacted clinical care, medical practice and medical education.