Ali and Sarah had a patient post cardiac arrest after hanging. She had 25 mins of CPR in the field. On arrival, she was tachycardic 110, BP 110/, sats 100% on FiO2 1. Jana did a quick lung and cardiac US. Cardiac US was unremarkable, but the lung US showed a pneumothorax on the R. Jana didn't save any images (!!!!). But it would have looked like this:
M mode of R anterior lung showing barcode or stratosphere sign
CXR done while preparing for R chest tube.
This was an excellent pick as the patient had sats of 100% and equal air entry clinically. US helped expedite chest tube insertion.
The patient deteriorated haemodynamically en route to CT. An inotropic infusion was started assuming cariogenic shock.
CT revealed a large liver laceration and intraperitoneal free fluid. (This and the tension pneumothorax likely secondary to rib fractures from CPR.)
Given the amount of free fluid: FAST exam would likely have been positive.
CT abdo showing FF fluid around the liver and spleen
We all use US in ED to answer a specific question: is there a pneumothorax, is there hydronephrosis etc. But when the answer is negative, sometimes we forget to look for an alternate cause.
I'll check for hydronephrosis in a renal colic patient and then forget to look at the aorta.
We are so sophisticated with US now, we can look at multiple organ systems and make pertinent diagnoses. US can help differentiate the undifferentiated patient.
FAST for free fluid is part of the RUSH exam for undifferentiated shock.
None of us would think to do a FAST on cardiac arrest patients with no trauma. However, remember this case the next time you have an undifferentiated shock and look at the pipes and the tank as well as the pump to determine the cause.
Emcit RUSH https://emcrit.org/rush-exam/