Cellsaver.
Let’s talk about Cellsaver.
Cellsaver blood is simply red cells in saline. Every institution has its own philosophy on Cellsaver- whether there exists some cutoff volume above which you shouldn't give it, whether or not it represents a heparin bolus, etc. When I was a fellow it was basically forbidden, the surgeons believed it was "bring-back juice." Which is, of course, ridiculous.
The manufacturers of Cellsaver systems recommend the washing fluid be saline, and so most institutions do this. For this reason, if you give any significant volume of Cellsaver, you may develop a hyperchloremic acidosis. And indeed, that's what was going on here- I had given probably a liter and a half of CellSaver because of all the bleeding after we came off. Now, there exist iSTAT cartridges that can tell you the serum chloride, but most do not. So it is very very easy to fall into the trap of looking at this gas, interpreting it as likely malperfusion, and going down that rabbit hole incorrectly.
The same thing happens in trauma, incidentally. You'll have someone come in, and between EMS and the ED they've gotten a ton of saline. You get a gas and they're acidemic. I've seen people say "oh I better give more fluid, the patient has a acidosis so they must be dry" and then they give MORE SALINE. Then they wonder why the acidosis isn't getting better. I've seen people start inotropes to try to "improve oxygen delivery" when all that's going on is an iatrogenic hyperchloremic acidosis.
So back to the case. Long ago, for this reason, I told my perfusionists that I want them to wash the Cellsaver in Normosol (you might have Plasmalyte, same same). They balked because the manufacturers didn't recommend it. But I convinced them, for this exact reason. But the dude pumping that case just forgot, and washed it in saline instead that day.
So when I got that gas, knowing that the Cellsaver volume had been significant, I asked him if he used saline. He fessed up and said yeah, he forgot. No biggie. Sent lytes and indeed, the serum chloride was 115. So this acidosis was completely benign, except to whatever extent a hyperchloremic acidosis is bad for the kidneys (and it may well be).
Last thing about Cellsaver. This whole business of it being "bring-back juice" is absurd. It's red cells in fluid. If they need red cells, give them red cells. BUT- always be cognizant of the volume, because a dilutional coagulopathy is a potential entity with any fluid you give that doesn't contain clotting factors. And while there might be a few molecules of residual heparin floating around, that's generally a clinical non-entity. Give a couple cc's of protamine after if it makes you feel better.
tl;dr the patient was fine, and the acidemia was iatrogenic. No treatment was needed.
