FAST Cardiac Ultrasound And Traumatic Arrest
Cardiac arrest in trauma patients is bad. Really bad. There are few survivors, mainly those who have some signs of life when they roll into the resuscitation room. One of the signs we look for is cardiac electrical activity, especially a narrow complex rhythm. But most of the time these patients don’t survive either. Could there be a way to fine tune the use of pulseless electrical activity (PEA) to better determine when further care is futile?
The trauma group at UCSF-East Bay did a nice, retrospective review on the use of the cardiac portion of the FAST exam to assess patients arriving in PEA arrest after either blunt or penetrating trauma. The numbers were a bit thin, but they were able to study 162 patients who had both FAST and EKG upon arrival. Of those patients, 71 had electrical activity, but only 17 had cardiac motion. However, 4 of these 17 survived (24%) vs only 1 of the 54 who did not have cardiac motion.
About a third of these 71 patients suffered blunt trauma, the remainder had penetrating injury. Of the 17 with cardiac activity, 14 were penetrating and 3 were blunt. And of the 4 survivors mentioned above, 3 were penetrating.
Only 1 of the 71 patients with PEA and no cardiac activity survived, and this was a blunt arrest(!).
Bottom line: Traumatic arrest is a generally fatal problem. However, it appears that use of the cardiac portion of the FAST exam in penetrating or blunt trauma can help fine tune the aggressiveness of resuscitation. PEA without cardiac activity is uniformly fatal (although there was one blunt survivor, the authors did specify the quality of this survival). It may be wise to forego further resuscitative efforts in PEA patients without cardiac activity because they will not survive, even as an organ donor.
Reference: The heart of the matter: Utility of ultrasound of cardiac activity during traumatic arrest. J Trauma 73(1):103-110, 2012.
Part 2: FAST Is Fast And FAST Is Last
I’ve received a fair amount of commentary on Twitter and via email regarding my statements about FAST. Many people said that FAST and physical exam can and should happen simultaneously.
In principle, I agree. My previous statements were based on the way that we organize our trauma team and trauma activations at this hospital. The reality is that everyone’s team is different and they may run their trauma activations differently.
The goal is to get all information critical to keeping your patient alive as quickly as possible. In some cases, knowing if there is a significant amount of fluid in the abdomen can be very important. Most trauma resuscitation schemes at trauma centers make use of multiple personnel so that various portions of the patient evaluation can be carried out simultaneously.
But there is also a tradeoff between speed, trauma team size and number of trainees. Centers with fewer or no trainees will have a leaner team with experienced examiners and more room around the patient. At our hospital, we have 8 people clustered immediately around the patient, with half of them being surgery or emergency medicine residents. This means it is more difficult for a physician to step in and do a FAST exam easily. So typically, this physician is the same resident doing the torso portion of the physical exam. This is the main reason for my exhortation to wait until the end of the physical exam and do the FAST quickly.
So it is really up to each center to determine their priorities for the FAST exam based on the people who make up their trauma team. At ours, it will have to remain fast and last.
Please comment or tweet your thoughts!
FAST IS Fast, And FAST Is Last!
Ever been in a trauma activation where it seems like the first thing that happens is that someone steps up to the patient with the ultrasound probe in hand? And then it takes 5 minutes of pushing and prodding to get the exam done?
Well, it’s not supposed to be that way. The whole point of adhering to the usual ATLS protocol is to ensure that the patient stays alive through and well after your exam. And FAST is not part of the primary or secondary surveys, it is an adjunct.
As always, there are a few exceptions to the rule above.
- If an unstable patient arrives without an obvious source of bleeding, FAST of the abdomen should be able to detect if a large hemoperitoneum is present. This will expedite the patient’s transfer to the OR.
- A patient in cardiac arrest may benefit from a quick FAST to determine if cardiac activity is present. If not, it may be time to terminate resuscitation.
Bottom line: With the exceptions noted above, always complete the ATLS primary and secondary surveys first. Then pull out the ultrasound machine, but be quick about it. If it takes more than about 60 seconds to do the exam, someone probably needs a little more practice.
The FAST Exam in Children
FAST is a helpful adjunct to the initial evaluation of adult trauma patients. Unfortunately, due to small numbers the usefulness is not as clear in children. In part, this is due to the fact that many children (particularly small children < 10 years old) have a small amount of fluid in the abdomen at baseline. This makes interpreting a FAST exam after trauma more difficult.
Despite this, use of FAST in children is widespread. A survey of 124 US trauma hospitals in 2007 showed an interesting pattern of ultrasound usage. In adult-only institutions 96% use FAST, and at hospitals that see both adults and kids, 85% use it. Most of these centers that use FAST have no lower age limit, and the physician most commonly performing the exam was a surgeon. However, only 15% of children’s hospitals do FAST exams, and they were usually done by nonsurgeons! The reasons for this are not clear. It appears that the pediatric surgeons have not embraced this technology as much as their adult counterparts.
What about that confusing bit of fluid found in kids? Several groups have looked at this (retrospectively). Fluid in the pelvis alone appears to be okay, but fluid anywhere else is a good predictor of solid organ injury. Fluid seen outside the pelvis had a 90% sensitivity and 97% specificity for injury, and positive and negative predictive values were 87% and 97% respectively.
Bottom line: FAST exam is useful in pediatric victims of blunt abdominal trauma. Fluid in the pelvis alone is normal in most children, but fluid seen anywhere else indicates a high probability of solid organ injury.
- Use of focused abdominal sonography for trauma at pediatric and adult trauma centers: a survey. J Pediatric Surgery 44:1746-1749, 2009.
- Minimal pelvic fluid in blunt abdominal trauma in children: the significance of this sonographic finding. J Pediatric Surgery 36(9):1387-1389, 2001.
- Clinical importance of ultrasonographic pelvic fluid in pediatric patients with blunt abdominal trauma. Ulus Travma Acil Cerrahi Derg 16(2):155-159, 2010.