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Interesting Case - Torrential Mitral Regurgitation

Todd Fraser on 05-05-2013

An interesting case was forwarded to me recently.  It was a 59 year old woman with diabetes and hypertension, who had what sounded like a delayed presentation of a myocardial infarction, and then ruptured her papillary muscle 4 days later, resulting in torrential MR, cardiogenic shock and acute pulmonary oedema.

 

After insertion of a balloon pump, she stabilised on 10mcg/min of adrenaline (epinephrine) and 5mcg/min of noradrenaline (norepinephrine).  This gave her an assisted systole of 70mmHg and an augmented pressure of 95mmHg.  Her lactate with this was 3mmol/L. She was commenced on BiPAP non-invasive ventilation with an FiO2 of 100% and has a respiratory rate of 30, with arterial saturations of 90%.

 

She required transfer from a rural intensive care to a major metropolitan unit by fixed wing air ambulance, and a decision was made that she required intubation first

 

So here are my questions :

  1. What induction agents would you use, and how much?
  2. How would you manage her inotropic and vasoactive agents?
  3. Given she is in pulmonary oedema and hypoxic, how would you manage her pre-load?  Diuretics?  More inotropes?
  4. What arterial oxygen saturation would you use?

Let me know your thoughts



7 Comments


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Sanjeev from India wrote 05-06-2013 06:49:56 am
I would be very concerned about cardiovascular collapse when inducting. I would give ketamine, maybe 60mg, and a small dose of fentanyl like 200mcg.

The balloon pump is good for supporting coronary blood flow so I would give her adrenaline to support cardiac output. Too much noradrenaline will make MR worse, edema worse.

I would aim for any saturations over 90%



Gordon West from United Kingdom wrote 05-08-2013 08:17:06 am
The key issue I think here is the afterload. I'm sure Sanjeev is right in that giving too much sedation is going to drop her blood pressure catastrophically, but I also think that you can't afford for her to get too stressed either. A large rise in her afterload due to poor sedation will make the MR much worse.

Similarly with the vasoactive agents, I think you need to support her output without increasing the afterload, so I think adrenaline or perhaps an extremely small dose of dobutamine would be appropriate.

With an augmented pressure of nearly 100, and a lactate that is tolerable, it sounds like the circulation is adequate, at least for the time being, so I wouldn't be trying to boost this too much.

Knowing what to do about her fluid balance is incredibly difficult, and might be best answered with an echo to see what her LVEDV was, but the pulmonary oedema is due to back flow of MR, not fluid overload, so I doubt diuretics make any difference. Using basic strategies to improve forward flow (maintain rate 100-120, reduce after load, positive inotropism, perhaps gentle diuresis) are going to make more difference.



Sean McManus from Australia wrote 05-12-2013 09:14:59 pm
This sounds eerily similar to a case we had last week in our non-metro ICU. Acute abdomen needing laparotomy (perf appendix found once opened) on background of dilated cardiomyopathy with severe MR. Inotropes 50mcg/min adrenaline & 50mcg/min norad (no balloon pump) for systolic of 90 mmHg.

We elected to use fentanyl 200ug + propofol 40mg + roc 100mg and adjust the inotropes as best we could. Interestingly, we actually turned the inotropes down and observed his mental state prior to induction. He coped well with a systolic of 70 mmHg, so we readjusted our goals accordingly.

If we were dealing with pulmonary oedema as in the case posted, one would assume that IPPV would assist in reducing preload and afterload, so the heart would be a little better off once through the stress of induction and intubation. Agree that maintaining forward flow is the key with severe MR.

As far as sats go - any number beginning with 9 is good enough, as long as we address all the other triggers of increased PVR.

Our patient did well and was extubated 5 days later.



Critq iq from Australia wrote 05-13-2013 10:54:57 am
I would use fentanyl 100 microgram and sux 100 foe intubation.
I would rather use inodialator like milrinone or dobutamine with adrenaline than noradrenalin as patient need reduce afterlord in MR. It would be usefull to have ome cardiac out put measures like picco.
I would use po2 over 60 rather tan spo2 as venous pulse may give false low spo2



Con from Greece wrote 05-13-2013 11:38:05 am
I would not use milrinone or dobutamine - BP could crash and you can't get it back. Adrenaline is best as beta effects cause dilaton too, but not as much.

Dont you get the venous pulsations with TR, not MR?



Rscha2 from Australia wrote 05-13-2013 04:36:05 pm
Good case, very high risk of arrest on induction for many reasons.

It is important to consider that this is a patient with competing haemodynamic goals:
1. Shock model and importance of adequate coronary perfusion pressure
- maintain afterload
- heart rate slow normal to optimise coronary perfusion time and decrease myocardial oxygen consumption

VS

2. Torrential MR and the need to maintain forward flow
- afterload reduction
- heart rate higher to minimise regurgitant time

I would continue the current adrenaline/norad infusions and IABP, put defib pads on pre-induction and have resusc doses of drugs available. Ideally she'd be in sinus pre-induction, if in AF and I had a bit of time I'd try and revert with some amiodarone (obviously if she's acutely decompensated then you're in an even worse position!)

I'd have skilled assistance depending who's around (anaesthetics vs another intensivist), clearly communicate plan and medication including doses if I'm intubating and not doing drugs

I would titrate my induction drugs carefully and continue with mask BiPAP while inducing if the mask had a good seal (useful for pre oxygenation)

I would give 1mg midazolam (to make me feel better) and then 0.5 - 1mcg/kg fentanyl in 0.5mcg/kg doses, then sux 1mg/kg; propofol handy to give in 10mg increments if she becomes too tachy/hypertensive at induction - to me shock model/risk of arrest with sympatholysis is greatest danger at induction. Ketamine is an alternative but I probably wouldn't use (Titrate slowly again, maybe start with 0.3mg/kg etc).

Once again important to remember this patient will most likely have a slow effect site circulation time so vital to be gentle, titrate drugs slowly (if she doesn't arrest)

I wouldn't pre-load with fluids, but after intubation I would give frusemide 0.5mg/kg - 1mg/kg; ventilate with as much PEEP as I could get away with to minimise FiO2 and titrate norad to adequate perfusion pressure (say MAP >70, aim HR ~80 as trade off balance between myocardial O2 supply/demand, and obviously maintain sinus rhythm). I'd keep on the adrenaline, ensuring I don't get to tachycardic re myocardiac O2 consumption (if so I might think about switching to milrinone but not for a plane ride). TOE if possible would be great after intubation if possible (valvular function, filling, contractility/output.

Cardiac output measurement via PAC/PiCCO is probably not going to be useful at induction, maybe afterwards if you want to play around. In reality you're going to be as gentle as possible whatever random number it generates.



Rjsseastres from Australia wrote 05-21-2013 02:00:55 pm
For induction- low dose Ketamine,moderate dose Fentanyl and std dose Suxamethonium (if normal K).For haemodynamic support in Cardiogenc shock, gentle diuresis Frusemide IV,fluid restriction for Preload, Adrenaline add Dobutamine or consider Levosimendan (if taking BBlocker) for CO guided with TTE/TOE and PA catheter and optimize IABP.Ventilate with generous PEEP and FiO2 to accept sat> 92% for acute cardiac events. Patient need urgent CTS r/v for definite correction of severe acute MR with HD compromise.



 

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