Ultrasound in Resuscitation: What Every EM Clinician Should Know

Bedside ultrasound has become a common tool in many EDs. Potentially one of the most important uses of ultrasound is during resuscitation. When a patient is crashing and every moment counts, having the ability to quickly assess the clinical situation and make critical decisions is paramount. 

A strong background in bedside ultrasound can help clinicians quickly identify life-threatening issues and initiate time-sensitive interventions. Whether ultrasound helps you differentiate among various types of shock, identify which consultant to call, or provide critical information needed to start the right therapy, it is a helpful tool that all ED providers should have in their bag.

Is an ultrasound always helpful?

It depends. Ultrasound has not been shown to decrease mortality for patients in shock, though it is likely to be helpful when assessing patients with a high clinical suspicion for specific badness (tamponade, ectopic pregnancy, massive PE). While an ultrasound may not directly reveal the patient's diagnosis, it can be very useful in guiding resuscitation efforts. This may have a downstream effect of narrowing the differential, based on the ultrasound findings and the patient's response to initial therapies. 

Ultrasound in cardiac arrest

The use of an ultrasound during cardiac arrest is complicated. It is most helpful in nonshockable rhythms or trauma arrests when you’re hunting for a reversible cause such as tamponade, PE, or a tension pneumothorax.  But in patients with a shockable rhythm (VT/VF), ultrasound often adds little. In situations where ischemia is the likely cause, the urgent need is to stabilize the patient enough to get to the cath lab, and in this situation, an ultrasound does not add much. 

When using an ultrasound during pulse checks, consider the following:

• Look for femoral artery flow during compression; it's more reliable than palpation. 

• Cardiac movement on an ultrasound is a better prognostic indicator for survival than having bystander CPR. 

• Cardiac movement without palpable pulses is a grey area, and there is not great literature as to when to stop compressions. 

While cardiac standstill on ultrasound is a dismal prognosis, there are case studies of patients living to discharge despite cardiac standstill at some point during their code. So in these situations, remember to consider the bigger picture and use your clinical judgement. A 25-year-old who just went down may still have viability, whereas an elderly patient with a longer downtime likely does not. 

Fast access in the right vessel

A patient with an empty tank and flat vasculature can be a resuscitation nightmare.

Establishing IVs can be a hectic ordeal, and you may find yourself called upon to quickly obtain central access. A brief look with an ultrasound may help guarantee the success of a crash femoral line. For patients with rock-bottom blood pressures and rising tachycardia, palpating a thready pulse to place an arterial line can be a challenging task — another situation when using an ultrasound can be the difference between success and failure. 

Taking a quick look versus the full clinical picture

If you are looking to do a complete bedside ultrasound for a rapid evaluation, this would include being proficient in all of the following exams and views:

• Heart: Tamponade, RV strain, global function

• IVC:- Size and collapsibility (fluid status)

• FAST exam: Intra-abdominal bleeding

• Lungs: Pneumothorax, b-lines, effusion

• DVT scan: (Optional)if PE is a concern

If all you want is the clinical bottom line, you should at least be able to look at the heart with reasonable proficiency. This will give you the most information in the smallest amount of time, and the least amount of skill needed. A quick cardiac ultrasound can allow you to identify which type of shock you are dealing with and allow you to start treatment accordingly. 

Bottom line: Is it worth it?

Absolutely. Compared to the massive costs and infrastructure investments required to expand services such as CT, MRI, or labs, ultrasound is the one diagnostic tool that is easily scalable to the growing number of patients seen in the ED daily. Advances in both cost and portability have made ultrasound one of the most valuable assets any emergency medicine provider can have at their disposal. 

It may not save the day in every clinical situation, but it can add clarity when the stakes are at their highest. But just like any tool, it is only as good as the person wielding it. Practicing ultrasound techniques each and every shift will ensure that when the moment comes, it may help you save a life.

For more information, subscribe to ERcast and listen to the podcast episode, "Ultrasound in resuscitation."