OK so I refreshed my knowledge a bit for this one. Disclaimer - I've been exposed to far more on-pump CABG procedures, but we have one surgeon here that insists on doing it off-pump whenever possible so I have a reasonable beginner-level experience on the subject.
Preop concerns - Plavix loaded. I have nothing more to say about the SYNTAX score than
@vector2 said above, but it sort of stinks that the patient got some. The best way to assess
qualitative platelet function in this situation is using the PFA-100 assay (different institutions may label it differently) which specifically looks at ADP-receptor function. At our lab, it gives a <5-to-100 result with 100% being normal function. There are a significant number of Plavix (and ASA) non-responders out there, so the platelet function is not a guarantee to be impaired. This isn't a case that can wait for return of platelet function (at least 5-7 days) so the purpose here is more for product management toward the end of the case.
90% left main disease - that's the real deal, and something to be taken seriously. IABP is a reasonable option as this patient is at risk for malignant arrhythmias. No need to have it on 1:1 (max support) given the good biventricular function (for now), 1:2 will be enough coronary perfusion augmentation to make me happy. I hear the platelet effects, but we will be dealing with those anyway and they are likely barely functioning to begin with. Elevating the CPP with norepinephrine by increasing afterload isn't my preferred strategy here, and probably increases the work of the heart. This patient is high risk, and an honest discussion needs to be had with the family and patient about a possible bad outcome here and their wishes properly documented.
- Some cardiologists will put Impellas in these high-risk patients. You'd only need a femoral device (CP or 2.5), running at P4-P6.
Intraop - Monitors: Standard with right radial A-line just in case peripheral ECMO is required at the end (not out of the realm of possibility). CVL with PAC particularly for ICU management afterwards, TEE for intra-op but if it goes OPCAB the views will be mostly lost when the heart is verticalized.
- Make sure you evaluate the position of the IABP if it's there with TEE, it very frequently is out of place (too deep) and you don't want to place the renals at risk. Proper position is 1-3 cm from the L subclavian takeoff in the descending aorta.
OPCAB vs On-pump: The newer evidence (trials - ROOBY, CORONARY are the biggest with ~ 2K and 4K patients respectively) shows a 5 year similar outcome between them, but the
1 year outcomes were more significant with off-pump procedures. I am not sure this is a totally applicable situation to apply as critical left main disease likely would have disqualified the patient from the trials. If the surgeon feels strongly then attempting is fine but I am putting my foot down - given the high risk for malignant arrhythmia and severe hemodynamic instability venous and arterial cannulas need to be placed and a CPB pump attached and ready to go. The other consideration here is that 4-6 vessels is a LOT for OPCAB - the numbers above are one thing, but what does the
surgeon plan to do - how many posterior anastomoses requiring verticalization when the hemodynamics are the worst?
- You'll need to volume load these patients sufficiently to handle the LV suction device, so watch closely with TEE so you don't overdo it.
Send coags when rewarming (off pump) or during the last couple anastomoses - specifically, PT/PTT/INR, Fibrinogen, TEG (with heparinase), Platelet count. If the PFA-100 preop was <20, have 2U Plt ready to go. You'll probably need more, this is not the case where blood product conservation will be utilized. Depending on what the opening PA pressures were, you might need some Milrinone as an inodilator. Will likely need some norepinephrine for relative vasoplegia (this will iikely be a long pump run), have a low threshold to add Vasopressin as well if PAPs are a problem given its specificity for the systemic circuit over the pulmonary circuit. Assess function with TEE, low dose ionotrope with epinephrine may also be helpful.
Then assess bleeding, check those coags that were sent. If there is any renal dysfunction, add some DDAVP following protamine. You'll likely need at least platelets, but also FFP given the dilution from the volume load you had to do. Cryo if fibrinogen is low.
Watch closely over the next 30 min to 1 hour, these patients are at risk for decompensating after things have settled out (where the PAC will come into handy in the ICU). If there is an IABP, closely evaluate the function and discuss with the surgeon - if things look good, you can take it out vs set it to minimal modulation (1:4) and take out the next day when stable.
I think that's all I've got to say. Good case, definitely some wiggle room with regards to management.