Answer 5

Differential diagnosis would include: hypovolemia (due to undetected hemorrhage), high spinal anesthesia, amniotic fluid embolus, air embolus, pulmonary embolus, coronary ischemia.

The TEE image of TG SAX view (clip 8) shows a dilated and hypokinetic RV, with an underfilled LV that has normal systolic function. This is also apparent in the ME 4C view (clip 7). The interventricular septum is flattened during diastole and systole, (note that the LV is “D” shaped rather than round), consistent with volume and pressure overload. (Acute pressure overload causes RV dilatation and an appearance consistent with chronic volume overload.)

This could be primary RV failure, (R coronary artery occlusion), or secondary to acute pressure overload from a large proximal PE, or pulmonary vasoconstriction secondary to air or amniotic fluid embolism. (The former is much less likely in a young female.)

Initial treatment would involve measures to support the RV. An inodilator such as milrinone would be ideal, but currently there is not enough blood pressure to tolerate the inevitable drop in SVR, so epinephrine infusion would be appropriate, (+/- a vasoconstrictor if required for MAP; vasopressin would be the best initial choice as it spares pulmonary vasculature). Inhaled nitric oxide (if available) would be useful to decrease PVR.

If embolus is not visible in the main PA, or proximal RPA on TEE then the patient may benefit from a spiral CT of the chest, (once she is stable enough to travel to radiology). (A large proximal PE with hemodynamic instability would usually be an indication for thrombolysis, though obviously in this case the patient is immediately post-surgical and so this would not be an option, but IV heparin +/- IVC filter may be appropriate.