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Welcome back to the tasty morsels of critical care podcast.
This is part 2 of infective endocarditis, this time covering the highlights of endocarditis management from the ICU perspective.
Once the diagnosis is made and checked that the diagnosis is solid (remember there are published criteria about how to reach the diagnosis) then you should be reaching for some antibiotics. The guidelines have multiple, tedious tables describing antibiotic combos for native and prosthetic valves all guided by knowing what bug you are dealing with. If you are at the stage where you know what bug it is you will almost have a specialist in infection giving advice so I think this is somewhat beyond the scope of the ICU exam setting. Having a broad overview that of what bugs are gram +ve and gram -ve I think is key and will allow you to put together an appropriate reigime in any septic scenario, not just IE. As such i’m not going to go into detail.
I suspect the more relevant scenario for us will be the crashing patient with an eaten out valve lesion at 2am and we’re the first person to be considering the diagnosis and have no micro to guide us. If you find yourself in such a situation then ceftriaxone and amoxcillin and some vancomycin will cover all the bases included prosthetics for the first 12 hours till help is available. This will cover all the commonest bugs of staph, strep, e faecalis and prosthetics. If you want to cover the weird culture -ve bugs then I have one, somewhat predictable word for you – doxycycline.
If they’re in crit care they’ll almost undoubtedly be septic and any of your arsenal of sepsis interventions is probably appropriate and again beyond the scope of this post.
The major modifiable part of your sepsis resus here will be determined by the echo. Are you dealing with severe, torrential AR then keeping the BP a little lower and diastolic period a little shorter with a tachycardia might be in your benefit. Have you got torrential MR from a perf or flail – then a balloon may be helpful. Again, the physiological management of a bad valve pending surgery is great fun but also beyond the scope of this post.
So perhaps time would be better spent thinking about surgical indications in IE. The guidelines again have fairly clear indications here but many patients fall foul of the usual problem of having surgical disease when they are not surgical candidates.
You can split surgical indications into 3 categories
- heart failure – this is the commonest indication and is driven by the degree of valve destruction and the heart’s ability to compensate for this. Cardiogenic shock and pulmonary oedema are obvious signs here.
- control of infection – the guidelines suggest surgery indicated if cultures not clear at 7-10 days or appropriate therapy. But these surgeries are often sensibly deferred to avoid putting what should be a life long valve into an infected patient. Persistent septic shock (even if cultures cleared) is another similar indication
- control of emboli – the guidelines would suggest very large vegetations (>30mm) should be operated on, even smaller veg (>10mm and other indications) could have surgery. However the risk of surgery is highest in few days before and after starting antibiotics and tails off signficantly at 2 weeks. As such you can imagine that many feel more comfortable with conservative management in this scenario.
Be aware that the guidelines use the words “urgent” and “emergency” differently from what we might expect with “emergency” not meaning “right now” but “within 24 hrs”. There are often multiple good reasons for deferring theatre when there is the opportunity to optimise someone for a challenging bypass run. Intracranial emboli with bleeds also pose a big challenge when you’re proposing giving someone 30000 units of heparin. Lots of painful but necessary MDT discussion needed.
Finally a common question appears regarding whether or not you anticoagulate to prevent the emboli causing strokes. . We do it when we find clot in the heart so why not veg (which inevitably have clot and infection in them). The guidelines give a reasonably clear answer with anticoagulation not recommended as a prophylaxis strategy. To give a direct quote from the ESC guidance “To date, no data support initiation of either antithrombotics nor anticoagulants for treatment or prevention of stroke in IE.” In distinction continuing anticoagulation in someone on it for pre existing reasons (eg a fib) does not seem especially high risk.
Reading:
– Fowler, V. G. et al. The 2023 Duke-International Society for Cardiovascular Infectious Diseases Criteria for Infective Endocarditis: Updating the Modified Duke Criteria. Clin. Infect. Dis. 77, 518–526 (2023).
– Delgado, V. et al. 2023 ESC Guidelines for the management of endocarditis. Eur. Hear. J. 44, 3948–4042 (2023).