50 years post mechanical AVR, off pump well for 1 hour, no support, normal ECG, normalTEE. Sudden drop of BP from 100 TO 50 over 1 minute with bradyc, distension, no response at all to vasopressors or inotropes boluses. CPB resumed for 30 min, off pump well. post op OK. Discharged 7 d postop.
Agree, likely it was an empty and hyperdynamic LV. Vasopressors and inotropes can only worsen the pt status. Echo would have clarified the pathophysiology of hypotension and allowed you to address proper management
The sudden bradycardia and cardiac distention does not fit with hypovolaemia. Although it is a bit late, gas emobism from an inadequtely vented LV, down the right coronary artery would precipitate ischaemia of the sinoartrial node so bradycardia as well as RV dysfuntion and distention.
The combination of hypotension and bradycardia does not fit very well to hypovolemia. I would also consider a gas embolism as one possible reason as well as a reaction on protamine. Finally, a ventilation problem can also not be ruled out.
Not sure if I understand what you mean bya 'ventilation problem'? Do you mean hypoxia?
That´s exactly what I meant. There may be different reasons like for example atelectases at the end of ECC and they all lead to short periods of general hypoxia.
The case was discussed in detail post op , being transient hypotension , not responding at all to inotrop boluses , recovered well post second pump, also TEE showed no air bubbles, most likely ventillator related hypoxia as suggested by Rainer Moosdorf . We surgeons, during hypotension or sudden arrest focus more on the surgical procedure mistakes or pitfalls and usually overlook anaesthetic related hypoxia which I think is not uncommon and usually missed
Routine, systematic evaluation of common problems is vital & one should diagnose (echo, ABG, reassess with NIBP, PA pressures, CI, O2 sats, EtCO2, etc) & treat quickly:
1) heart-myocardial protection, air embolus (RCA commonly), interruption of infusions (inotropes &/or vasocontrictors), acid-base, electrolytes, etc.
2) lung-hypoventilation, hypoxemia, PA hypertensive crisis, etc.
3) hypovolemia (with diastolic duysfunction one can have profound swings in BP), hemorrhage (related to surgery, cath & retroperitoneal, eetc.),
4) less common problems like anaphylaxis (drug or transfusion reaction), adrenal insufficiency, etc.
Post cardiac Surgery hypotension is not an uncommon phenomena.
Most common things are
1.Blood loss
2.Hypoxia
3.Hypovolumia
4.Cardiac tamponade
5.Heart block
6.Pneumothorax
However other causes such as PE, sudden vagal response from Endo tracheal tube cannot be ruled out.
It is also of paramount importance to keep in mind that whether the patient had a normal coronaries.
Profound hypotension post cardiac surgery is a not uncommon problem and the causes are a lot.
In my opinion a late anaphylaxic to protamine sulphate is not impossible.
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