Case vignette
A 22yo M presents as a full trauma after stab wound to the right chest. He is somnolent on arrival.
HR 140, BP 70/40, RR 22, SpO2 92%, T 36.5.
Altered male answers questions intermittently. He has equal breath sounds bilaterally and muffled heart tones.
What do you see?
Tr1 subxiphoid 1: hypoechoic (fresh) blood and hyperechoic (clotted) blood, RV free wall notching, impaired RV filling, small and underfilled RV and LV
Tr1 subxiphoid 2: dilated IVC (frequently one of earliest signs of tamponade)
What do you do next?
A fluid bolus is given to augment pre-load as the patient is emergently taken to the OR.
Teaching points. Have a low threshold for US with any penetrating wounds near the thorax, especially for patients with shock. While hemorrhaghic shock is always high on the differential, obstructive shock from a tension pneumothorax or cardiac tamponade must also be considered prior to transport to CT.
US can show pericardial effusion, impaired ventricular filling/interventricular dependence, and a dilated IVC. Note a dilated IVC is frequently one of the earliest signs of tamponade, however this finding can be absent in the setting of concurrent hemorrhagic shock (i.e., a false negative).
In addition, US can sometimes show clotted blot, which could make pericardiocentesis less effective and provide support for a thoracotomy (in the OR, if possible).
If the patient arrests, classic teaching recommends ED thoracotomy for arrest within 15 minutes of penetrating trauma and 10 minutes of blunt trauma. However, in low resource settings, cardiac US to assess for cardiac motion and pericardial effusion can guide the direction and utility of this intervention.
Residents/staff: Dr. Andrew Richards, Dr. Ramsey Selbak, Dr. Brandon Maughan
Traumatic pericardial effusion/tamponade