Ultrasonography as a tool in wartime trauma management first gained widespread use during the First Gulf War, and its use has grown substantially over the past decade and a half of conflict. While most recently graduated surgeons and emergency physicians seem to embrace this modality, it can be challenging for providers who did not receive US training in their residency. Most are familiar with US, but lack the training and hands-on experience to really apply it at the bedside. That’s the rub; not only does the trauma doctor need to know how to interpret and act on US images, he/she must also learn the skill of obtaining usable images in an acceptable amount of time.

This brief chapter is not designed to take the place of proper US training or an US course, but rather to give an overview and some references/reminders for US applications. Despite feeling comfortable or even competent performing US, true proficiency will only come through performance of dozens of extended trauma ultrasound exams. Furthermore, these skills will degrade if not practiced continually. There is a big difference between thinking a patient probably has a pneumothorax on US and actually knowing it exists (and placing a chest tube based on your US findings without obtaining other radiologic studies). If you are a deploying surgeon or physician who will be managing any type of combat casualties, then you must become familiar with the basics of ultrasound and the standard trauma exams (focused assessment with sonography for trauma or FAST ) before you deploy. With very little additional time and effort, you can add the skill set of basic thoracic imaging to perform the extended FAST exam (EFAST ).

The great news is that most of us will be deployed with easy access to an ultrasound machine, and deployment is the perfect time to refine/maintain our US competency. Tap into the US expertise of skilled ultrasonographers in your unit – be it the radiologist, emergency physician, or trauma surgeon. Apply the skills you know and practice repeatedly on your medics or EMT patients until you feel very comfortable with the probe positioning and the images you obtain. If time allows, as you refine your skills, go back to the stable trauma patient who has already had a positive CT finding and perform a US. Alternatively, bring the machine to the ICU and perform exams on patients with known intraperitoneal fluid (usually postop) or cardiac effusions. Recognizing positive findings and learning how intraperitoneal blood, pericardial blood/fluid, or intrathoracic blood/air looks on US is a critical part of attaining proficiency. Most of us won’t attain proficiency until we have performed and interpreted numerous positive EFAST scans, in addition to our “training” scans on normal patients. Once you have developed the basic skills of image acquisition, start working on efficiency. If you cannot do this quickly in a trauma resuscitation, team members can get annoyed and the slow ultrasonographer usually gets pushed out of the way. You must be able to obtain the information both accurately and efficiently, or this modality isn’t very helpful.

Before you deploy, make certain that your unit will have at least one functioning US machine, or have your unit purchase one. If deploying with a CSH, get your command and supply personnel to help purchase multiple machines. US machines in the CSH will likely be in constant demand from intensivists, radiologists, and other providers. There will be times when you need an US for the evaluation of a critical patient, but they may be tied up in other parts of the hospital. Think about this in advance, since it can be very hard to get additional or upgraded US units in theater. Also have your supply folks consider the wear and tear, and coordinate with the manufacturers for replacement parts and repair ahead of time.

The EFAST (Extended Focused Assessment with Sonography for Trauma) is the basic US exam used to evaluate thoracoabdominal injury. There are four basic views that are traditionally obtained in the FAST exam: right upper quadrant (RUQ ), left upper quadrant (LUQ ), pericardium, and pelvic. The “E” or extended portion of the EFAST came about after thorax scanning for pneumothorax was added later. Evaluation for hemothorax is more commonly being performed as part of the FAST. Search for blood above the diaphragms as you do the RUQ/LUQ abdominal views. Below is an explanation of basic techniques for obtaining views. Realize, however, that the EFAST is a dynamic process, not a series of 4–6 images. Slide the probe around and look at each view from different angles to increase your sensitivity. Placing the patient in Trendelenburg position may increase the sensitivity of your RUQ view if you are unsure if there is fluid on the pelvic view. Also, recall that a negative EFAST, particularly early in the evaluation, might still be missing accumulating blood in the intraperitoneal or thoracic space and that results should not be used in isolation when managing a trauma patient. EFAST should be repeated in certain clinical settings if initially negative. We should view US as a dynamic process and interpret results in light of the patient’s clinical picture and stability. Free intraperitoneal or intrathoracic fluid (unlike fluid within organs) tends to form collections with sharp edges or triangles as it settles between structures, rather than rounded edges seen within a viscus. Free fluid will also change size with patient repositioning and accumulation or drainage of fluid from that space.