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Clinical Case 077: Fluid balancing act

This is a tough one – a clinical scenario that is unfortunately a bit too common in my part of the world.  I want to know how you would go about balancing the fluids in this case, what will you use to measure the adequacy of the resuscitation / fluid administration.  It is a tight rope with not much safety net!  Here we go:

The Back story

Mr Beans –  60 yo. man with end-stage renal disease, he has been on HD for 3 years in a small country town satellite dialysis unit.  He has the usual comorbidities: uncontrolled type 2 DM, bad peripheral neuropathy, hypertension, has had 2 separate angioplasties for coronary stenoses now > 10 years ago (no recent angina), obesity – BMI 37 with marked central adiposity, probable sleep apnoea on history – not diagnosed yet!  He is on all the usual renal failure meds and calcium-control agents and beta-blocked, on aspirin but not clopidogrel.

His last admission was for APO following a week of missed dialysis which got better with BiPAP and some dialysis.

Has had multiple AV fistual formations and failures, central venous stenosis requiring a surgical bypass – so not really able to do central access about the neck!  Difficult periphreal venous access.

The recent history:

Mr Beans was going well until he trod on something a week or two ago (no shoes ever worn).  He developed a soft tissue infection on the sole of his right foot which was drained in ED and placed on oral ABs.  The swabs came back with: MRSA, mixed coliforms and some anaerobic bacterium.     He then went bush for a week for some family business, missed 2 doses of dialysis (usually 3 times a week).  He returned for dialysis and got started on the machine when he spiked a fever – he had a nasty looking swollen right foot with superficial blistering and a nasty odour.  The team pressed on with dialysis and decided to give him a dose of vancomycin at the end of the session.  Two hours later he was becoming hypotensive.  He was removed from the machine and sent over to ED.

The problem now:

Mr Beans clearly has a large purulent collection with subcut. emphysema over the whole dorsum of his foot.  There is a small draining wound on the sole of the foot.  His Obs: Temp = 38.2  pulse = 75 in SR,   BP –  110/70,  RR 20/min,  he is 3 kg over his preferred ideal body weight.  He lookes flushed and feels warm all over

A VBG is surprisingly normal aside from a lactate of 3.9 mmol/l.  His K+ is 4.8

Of course we do an USS of the foot – which shows a lot of artefact from the soft tissue gas.  On some views we can see deep fluid collections extending down between the metatarsals.  It stinks, not a nice fruity Staph smell – but something else!

The way forward:

The surgeon is keen to get Mr Beans to the OR for debridement / amputation tonight.  This sounds like a good idea until you realise that you are the Anaesthetic guy on call!  You have just heavily sedated a Psych patient and a 27-weeker has rocked in with contractions – it is not going to be a fun night!

Questions that need answers:

(1)  How are you going to assess Mr Bean’s current fluid status or need for fluid resuscitation?

(2)  How are you going to decide when enough fluid is enough / or when to give some vasopressors?

(3)  What are your initial / preferred plans for anaesthesia.  Looking at the spine there is a large fat pad, no palpable spinous processes below the chest.

(4) Antibiotic preferences for this scenario with ESRF?  Has been on vancomycin for 2 doses now, was on oral   Augementin (in theory; last week)

Do you have any pearls to share on this case?  Hit me on the comments, email or twitter

Casey

 

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Comments

  1. Some thoughts (in reverse order):

    4. Microbiology.
    This man has polymicrobial diabetic foot infection with MRSA. Standard treatment for diabetic foot infection would be timentin or piptaz; both of these A) have quite a large sodium load B) don’t cover MRSA. I think it would be fair to call it synergistic gangrene at this point (based on the USS description) and go for meropenem +- lincomycin. I don’t know what variety of MRSA this is, and you don’t mention this man’s ethnic background, but among the Indigenous population the NORSA rate is >50% (of all SA), I’ve heard (I’m not a microbiologist). The linco will help treat the majority of NORSA.

    So in summary, I would use meropenem, clindamycin and vancomycin in this man as triple therapy.

    3. I have no experience in anaesthesia -- but would this be suitable for ultrasound guided combined femoral-sciatic block? (I once plated an ankle with that sort of block -- worked well, but not having tourniquet was not fun).

    If his peripheral neuropathy is really bad, perhaps it doesn’t need that much anaesthetic after all. How extensive is the synergistic gangrene? Lisfranc was famous for being able to perform his eponymous amputation with great alacrity.

    2/1: I would try to use an ultrasound endpoint: either leg-raise fluid responsiveness, IVC collapse, or the appearance of pulmonary oedema.

    • Awesome answers Hildy
      Yes, regional anaesthesia is gold in his scenario. A single shot spinal SAB is probably the easiest and simplest option I reckon. But failing that a sciatic or popliteal block is good.
      I really try to avoid a GA or sedation in his scenario.

      In this case the next dialysis spot was 24 hours and 2000 km away! So choose the agents we inject carefully as they may still be there tomorrow!
      Main problem with spinal is the vasodilation making the distributive shock worse -- so a prophylactic phenylepherine infusion is handy. It also avoids tachycardia which we don’t want with this patients IHD.

      Thanks for the comments on AB choices -- I think there is a false idea out there that pip/tax kills everything -- but there is resistance in some MRSA strains. I like lincomycin/ clinda as adjunct. Got a post on AB choice coming up soon -watch this space.
      Vancomycin is already on board, and no dialysis nearby, so -- it is still there.

      The IVC US debate is raging recently -- checkout Ultrarounds by Haney Mallamet. I think the idea of fluid tolerance has a place here: fill until you see some B lines then stop, consider vasopressors if the CO is still lagging and the LV appears full / functioning and not hyperdynamic.
      Personally I would chase the lactate over the next few hours and look for evidence of other end organ hypoperfusion -- mental state, liver, cool peripheral bits. Put it all together to assist your choice of fluid / pressors

      Thanks. Casey

      • There should be resistance in all MRSA strains to pip/taz (and indeed, to all beta-lactams available in Australia -- I wonder if we will ever get ceftobiprole).

        Linco/clinda as an adjunct serves two purposes, here -- both the synergistic gangrene toxin binding effect, and also has better tissue penetration than vancomycin.

        Meropenem has good activity against pretty much everything that pip/taz does well, but with maybe a different ESBL resistance profile. I don’t know how much sodium there is per vial, though.

  2. Great case, we see this a bit up in Darwin, but usually a bit sicker, without a clear source!
    Clearly the foot needs chopping, possibly all the way off…
    Re fluid status, I had been struggling with the concept of fluid loading hypotensive dialysis patients until a friendly Renal Reg told me recently that you can usually fill them to 3-4kg over their ideal dry weight, so your man may be able to tolerate another litre, maybe 2 max before becoming overloaded. Of course if he starts getting a bit puffed -- he goes back on the filter, +/- inotropes to maintain a reasonable MAP.
    Re his BP: Systolic of 110 may actually be quite hypotensive for a renal patient, so would be suspicious of looming/current septic instability even in the absence of a tachycardia, which will potentially be worsened by a GA.
    Re anaesthesia: Not a gas-man, so the choice of anaesthetic is tricky. How does the haemodynamically stable flavour of the month ketamine (+/- a whiff of fentanyl) sound? Not actually sure how Vitamin K goes with non-functioning kidneys…
    Antibiotics -- I’d phone a friend for that one (I know you don’t have a CT, but you do have phones in Broome, right?!). However the main antibiotic he needs is surgery.
    Be interested to hear how it panned out, a classic “jack of all trades” Broome clinical conundrum!

    • Hi Andy -- yep it is northern specialty.
      The obs are very deceiving -- usually a HD patient who is 3 kg over weight, would have a high BP -- sometimes spectacularly high! So 110 is likely pretty low relatively. Also beta-blocked so the pulse rate is falsely low. He is a bit tachypnoeic, so might be in early APO already. Lung US to the rescue.?

      I am avoiding a GA AT ALL COSTS. See comment to Hildy. Hail Mary spinal was the go here

      Ketamine is converted to norketamine and a few glucuronide metabolises which are active and largely really excreted. So it might hang around a long time in a distributed state.
      Not a great plan if we have no HD machine on the horizon. Maybe Minh would differ? One of the bugbears of remote dialysis is they are not allowed to go for HD if too sick, which leaves us in a bind often, with long scary transfers!

      Yes, we use the phone -- I think it is a good idea to get expert opinion early so you optimise ABs and avoid toxic combination in a renal patient.
      We do have a CT now! Attracts a lot of work :-)
      Thanks mate. Casey

  3. minh le cong says:

    hi folks
    Mr Bean worries me.
    In tropical northern australian medicine, he has the full hand for crashing sepsis spiral to death.
    DM, ESRF, severe soft tissue infection
    The ones I have retrieved like this have all died.
    This guy needs to go to an ICU for a while so would be arranging the retrieval as a first line priority.
    Now I agree, having surgical treatment for his nec fasciitis is vital ASAP but how to do that safely and prepare him for an aeromedical transport post op?

    Some decisions to make with consultation with receiving ICU and patient. Is the plan to operate and transfer for ICU recovery? Is the plan to operate and recover locally and hope for the best? What does the patient and family wish and consent for?

    All the disasters I have witnessed have been when delays to ICU transfer have occurred, with plans to try to medically manage the septic renal failure patient in remote hospital for a period of time in hope of some improvement.

    But let us say for now the plan is to operate and recover locally in remote hospital.
    Fluid status..tricky in ESRF patient on HD..I would do lung USS to assess for oedema and if signs of that, be very cautious how much IV fluids I give..in fact I would be very keen to get him to an ICU for further dialysis and surgery. If the local HD unit in remote hospital will not dialyse him there as he is septic, I would be very reluctant to give IV fluids if signs of pulmonary oedema on lung USS. I dont think IVC USS is helpful at all in this case. We know he is likely fluid overloaded already by his weight measure . And we cant rely on urine output at all!
    If the decision is to operate prior to retrieval for control of infection source and he is in pulmonary oedema on USS… optimise pulmonary function with BiPAP trial, reassess in real time with lung USS..discuss with ICU and anaesthesia dept in tertiary hospital but I tend to err on side of controlling airway and ventilation if the patient is already in respiratory compromise. All nec fasciitis cases I have seen with DM and ESRF have all ended up ventilated eventually as they just spiral out of control with their sepsis. In my mind it is safer to anaesthetise them fully early when their physiology is better able to tolerate it rather than wait for when it is worse.

    There is no doubt he is a high risk GA but this will not improve with time..he will always be high risk..if anything with his sepsis his risk for GA increases with time.

    So if the decision with iCU is he gets flown out post op, I would favour RSI and ventilate him. I would use ketamine solely. leave him ventilated for transfer. Once ventilated you can consider more IV fluids if lung USS shows no oedema.
    Now if decision is to operate and recover him locally, although I think you are delaying inevitable, one could consider a regional technique like spinal or popliteal. I would go popliteal as you can place a catheter for post op analgesia and supplement during operation with IV fentanyl, bolus or infusion
    my concern with this approach of operating and recovering in remote hospital, is will dialysis service be able to dialyse him post op?

    Now antibiotic wise, everyone up north with a fever and looking remotely SIRS, sepsis, gets meropenem. He is dialysis patient , so should get vancomycin too. Diabetic foot infection should also get anaerobic cover which is usually adequate with meropenem but discuss with regional ID service in regard to metronidazole as well.

    My first pearl is this. Dont sit on these patients with severe soft tissue infection, DM and ESRF. they are time bombs. They often need acute dialysis, acute surgery and acute resuscitation including anaesthesia, all at once! their place is in big ivory tower hospitals with lots of machines and staff.
    My second pearl is sit down with patient and family before you embark on all this critical care stuff. Culturally you will be regarded as the expert voice but you need to guide them into making a decision they can feel right about. Dying off country or away from your sociocultural locus is a big deal in some communities. Although it may be big risk, if you and patient decide to do the best in the remote hospital and accept that post op things might worsen but a reasonable palliative plan is in place if that occurs, then that is being a healer, not just a technician.

  4. Graeme Pickford says:

    In Bathurst (nsw) we have an anaesthetist who is passionate about haemodynamics, and has schooled us in using an USCOM (continous wave doppler cardiac output monitor) to quickly and non-invasively measure indices such as cardiac output, systemic vascular resistance, inotropy, and FTc (flowtime corrected) in ED. It would be gold in this scenario.
    I would optimise his haemodynamics by titrating fluid to preload using FTc (which is great for this so long as read in conjunction with inotropy and afterload). I would bring his SVR up to low-normal if needed with noradren, rather than blindly run in fluid he mightn’t need; and sometimes in sepsis (particularly gram neg) extra inotropy will be needed to put the patient on a fluid responder curve on the starling curve.
    I’d start on DO2 but you’re probably already think I’m late for my tablets, (but the point I’m making is that these concepts are useable even in smaller EDs)

  5. Minh Le Cong says:

    one question Casey?
    Why did you do USS foot? to look for FB? to me it sounded like it was a bit beyond a simple FB removal procedure at the point you described!

    I would also be a bit worried about contaminating my USS probe with nasty bugs that might get spread to a CVC site insertion for the next patient! But thats what disposable probe sheaths are for..right..cause you did use one of them, right?

    • Good points Minh
      The USS was done in the X-ray dept -- I was at home
      Always use a cover when pus about then wash it ++
      USS is good for finding collections that X-ray misses
      C

  6. I’m like a baby amongst giants here (only a jr doc), but have some additional comments re: GA vs RA -- whilst I agree that a spinal is probably the best choice, we should not overstate it’s benefits. SAB still carries a significant cardiovascular risk, especially in a guy with a troubled heart. There are also the other effects with vaso-dilation induced hypotension mentioned earlier, which is a big issue in a septic patient. It’s main benefit would be to avoid an airway disaster (high risk in a patient of his size).

    I recall doing a case somewhat similar (although much less sick) during an anaesthetic term -- big guy with a nasty foot infection needing an emergency below knee amputation. He had a pneumonia as well, so intubating him would have meant ages in ICU trying to wean him off the vent. We went for a SAB, which for some reason didn’t work properly, and he started screaming once knife to skin occurred. Wanting to avoid intubation at all costs (ICU beds were all full) we managed with titrated dose of midazolam (hopefully he wouldn’t remember the whole terrible experience), fentanyl, morphine, and *nod to minh* a lot of ketamine, making sure he still maintained his airway. He became slightly delirious towards the end of the procedure and started grabbing the anaesthetic equipment, but at the end, he was all smiley, told us about the wonderful dream he had and barely even realised that the operation was over. All of us needed to go for a shower after that.

  7. minh le cong says:

    thanks Sing
    communal shower after ketamine sedation after failed spinal block
    wow, now I have heard it all!

  8. I have been cautioned against SAB in sepsis. Not sure if there’s an evidence-base or anaesthetic anecdote-based medicine

    But like Minh, the one’s I’ve seen in my training have done ‘badly’ (euphemism for transfer upwards)

    Whilst I am in awe of USS to assess filling (and laud Graeme for coming on board to suggest USCOM -- I know it has it’s accolytes..but bears of lil’ brain like me do not pretend to understand)

    Heck, I’d be getting him out of Dodge AFTER a frank discusison with patient/family -- and mindful that this may not be what they want, but making it very clear that deterioration and palliation are likely outcomes if stay and play.

    Fluids, inotropes, mero and vanc and RSI for transfer to somewhere bright and shiny…transfer n treat, innit?

    How did it pan out?

    • http://www.asra.com/pdf/Regional-Anesthesia-in-the-Febrile.pdf

      I think removing his foot prior to transfer may lead to better outcomes than delaying it by six hours.

      • Thanks Hildy
        I think that the risk of spinal block in sepsis is overstated. Typical paraganda or propanoia from our superstitious forebears. A medical myth needing debunking.
        I would not put a catheter into the epidural space -- it is unnecessary in the situation described. But a clean subarachnoid block is safe. The risk of seeding meningitis is so small that it is indistinguishable from the background rate if badness in this patient.
        I used a one-shot spinal with fentanyl and heavy bupivacaine
        Phenylepherine infusion running pre- block

        The BP and HR didn’t move. Patient was awake to negotiate his surgery with the team as they dissected up to clean tissue.
        All round good outcome
        C

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