Ultrasound in HEMS

Critics out there may slight the use of ultrasound in the prehospital environment, saying it is just going to delay patient transfer and won’t add much to your decision making.  However, when used properly, the ultrasound should never delay patient care and, when used in the correct patient population, it could help greatly in both decision making and treatment. Let’s first talk about when to use it.  The logistics of this may be a bit tricky.  The ultrasound is stored in the center console in the back of the helicopter.  You could take it out and carry it with you to the back of the squad, however you never really know what you are going to encounter when you open up that squad door.  It could be a totally stable, awake, talking patient who doesn’t really need that ultrasound right that second.  It could be a seriously sick, GCS 6, needs to be intubated and flown as soon as possible type of patient.  During the controlled chaos of taking care of that patient, it would be very possible to accidentally leave the ultrasound behind (very much a no no).  It is likely better to leave the ultrasound in the helicopter and use the ultrasound as part of your secondary or tertiary survey in the back of the helicopter.  This does mean that the flight nurse is likely to be in a better position to perform the exam.  If they are busy, then you’ll need to practice performing a FAST or the RUSH exam from the head of the bed.  Not impossible but not necessarily easy.

Now lets talk about what patient’s will likely benefit from it.  First there are the patient’s that need a procedure that will benefit from ultrasound guidance.  Since the only probe we have is the phased array probe, this pretty much means those patient’s who need a pericardiocentesis (more to come from this in the coming weeks).  Then, there are patient’s with hypotension.  Yes, hypotensive patients in the prehospital environment are in all likelihood volume depleted.  However, imagine this:

  • 65 yo male, involved in a MVC, +air bag deployment, +seat belts
  • BP-85/44, P-88, R-22, O2 sat- 95% on NRB
  • GCS 13 (confused, and eyes closed)
  • Physical exam without any obvious signs of significant trauma, no abdominal tenderness or distension, no pelvic tenderness or instability

Is this patient volume depleted? Or, do they have a pump problem?  Was there some cardiac contusion? Was there a medical cause that led to the MVC (AMI leading to cardiogenic shock).

If only there was a tool to help figure out what the cause of this patient’s hypotension is… If only..

For a little more reading and/or listening on how to do the RUSH exam, check out these great FOAMed resources from Academic Life in EM and EMCrit.