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Case for discussion

Discussion in 'Internal Medicine and IM Subspecialties' started by punjabiMD, May 1, 2007.

  1. punjabiMD

    punjabiMD 10+ Year Member

    167
    0
    Aug 4, 2002
    Scottsdale, AZ
    The following is an interesting case taken from our Night Float rounds.

    You are called by the lab for a panic value of potassium = 7.6 from blood drawn 3 hours ago. The serum creatinine is 3.5 and the bicarb is 18 with a normal anion gap. You go to see the patient and find that he is a 58 year-old man transferred from an outside hospital for cardiac cath. He presented to the outside hospital two days earlier with a NSTEMI with evidence of CHF and was transferred to this hospital 12 hours ago.

    His most recent previous electrolytes, from yesterday, show a potassium of 5.1, a creatinine of 2.3 and a bicarb of 22. You find the patient agitated and restless. His BP is 90/60 (decreased from 120/75), pulse is 78, SO2 is 86% on room air, rales are evident by auscultation, and extremities are cool. ECG shows sinus rhythm with a wide QRS complex (0.14, increased from 0.09 upon admission). T waves are flattened (not peaked).

    • What is your presumptive diagnosis?
    • What do you do?
     
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  3. sacrament

    sacrament somewhere east 15+ Year Member

    Hey, I suck at this. I mention that because I'm finding it to be a very sobering realization right now. (Not that I'm just now realizing it. I'm re-realizing it.)

    But I'm going to play because I don't mind public humiliation. That's what the junior high school basketball team taught me. I'll go with post-MI cardiogenic shock... and he's in the right time frame to consider things like mitral valve papillary muscle dysfunction. (I'm not sure why he isn't more tachycardic, maybe because he has been aggressively beta-blocked status-post NSTEMI.) This led to hypoperfusion of the kidneys (and of everything else, hence the cool extremities and goofy state of mind) with subsequent renal insufficiency contributing to the hyperkalemia (in conjunction with the ACEI that was recently started...?) The non-gap metabolic acidosis (no ABG given, but I'll presume) might best be explained, of the possible options, by Type IV RTA. Beta-blockers, ACEI, spironolactone and heparin--all of which, given the circumstances, he may recently have been started on--can all precipitate Type IV RTA. I think. (Okay, I just cheated and went to look that up. We're good to go.) Um, okay, the widened QRS can be from the hyperkalemia. The T waves are flattened because the expected peaking is obscured by recurrent ischemia the patient is now experiencing (does that happen? seems like an elevation plus a depression would make a flattening). Or maybe because the initial blood sample was hemolyzed and the patient isn't hyperkalemic at all. I'll give some calcium gluconate, redraw the potassium along with cardiac enzymes (won't wait for the results before starting kayexalate and the rest, I suppose), an ABG will be cooking, all while I'm waiting for the stat bedside echo to evaluate for mechanical causes of cardiogenic shock (acute MR, tamponade, free wall rupture, etc). Presuming no blown-out structure requiring emergent OR time, or tamponade requiring a needle, that cath is now in this guy's immediate future to see if he needs urgent revascularization. Okay, how wrong am I?
     
  4. Adcadet

    Adcadet Long way from Gate 27 10+ Year Member

    First things first:

    A is for Airway - Make sure his airway is open - based on your description I'm guessing this isn't an issue.

    B is for Breathing - Get the guy on as much O2 as you can. Start w/ nasal cannula, and if that doesn't bring his O2 sat up to >95 go to a non-rebreather. Sit the patient up. While working on that try to make sure you've got a good pulse ox reading. If we still can't get his sats above 90% on 100% by non-rebreather he may very well need intubation and mechanical ventilation. If somebody more experienced that me wants to try CPAP they could, but if it's that bad I'd go straight to an ETT.

    C is for circulation - He has a pulse bu this BP is falling. Not ready quite yet to call a code based on this alone. Between post-MI badness (like a papillary muscle rupture, re-infarct, etc) and a K of 7.6 I'm worried. Push the calcium carbonate/gluconate. Kayalexate can wait a bit as it takes too long to kick in. I'm not about to start this guy on a beta agonist now.

    Now that I think he's not going to die in the next 2 minutes, I want to make sure he's in the right spot. If he's a floor patient I want to call the CCU or MICU resident/fellow and alert him/her about a possible transfer, the most pressing reason being acute respiratory failure. The cardiology fellow also needs to be called, especially if we're thinking re-infarct/evolving MI that needs urgent PCI. And if I'm an intern my senior resident need to be alerted to this patient (duh).

    My working DDx:
    - pulmonary edema secondary to cardiogenic shock or a ruptured papillary muscle, especially a mitral if this guy has had/is having a an inferior MI

    - acute renal failure, caused by who knows what at this point (maybe secondary to cardiogenic shock, emboli, thrombosis, hypotension less likely)

    - cardiogenic shock of unclear etiology, but likely suspects include papillary muscle rupture given what seems like pulmonary edema, re-infarction/new MI

    Treatment to start now:

    - oxygen as described above
    - the typical MI stuff - ASA, heparin (I'm assuming he's been on it), a beta blocker (again, probably already on one), nitro and morphine for significant pain if I think his BP can handle it
    - calcium to stabilize the myocardium, and moving on to insulin and D50 depending on what the ECG and repeat K shows.

    I want to get some labs/studies, all stat:
    - ABG now, repeated in 10 minutes after we get some O2 on him
    - CBC
    - Chem 10, especially for the K
    - aPTT assuming he's been on heparin
    - troponins and CK-MB now and repeated q6 hours x3
    - portable chest X-ray to eval for pulmonary edema, lung processes, cardiac tamponade, heart size, any dissections
    - ECHO, looking for valve function (especially mitral), estimate LVEF, amount of pericardial fluid, any regional wall motion abnormalities, and depending on what I'm thinking re: lung processes, perhaps even looking for a pneumothorax
    - never heard about his temperature, would like to know if he's spiking a huge temp or very hypothermic as that could change my thinking
    - review his meds - stop any negative inotropes, and re-think any renally cleared meds

    Next steps depending on what my initial evaluation shows:
    - further airway management, as discussed above
    - if it looks like straight up pulmonary edema I'd start some diuretics, particularly the K-loosing ones like furosemide. Depending on his condition and what my physical exam showed, I might push the furosemide earlier on
    - if the CXR is pretty clear and I convince myself that I didn't hear crackles, I'd have to switch from thinking about pulmonary edema to hypovolemia and begin fluid resuscitation with NS (not LR because of the K) and maybe blood depending on the CBC
    - if if seems the cardiac output is too low (based on ECHO findings and BPs together with my clinical impression of whether he needs more output) I would start a pressor, most likely dopamine or norepi if his BP is low, or dobutamine if his BP is OK.
    - if the BP continues to suck, think about an intra-aortic balloon pump
    - assuming nothing surprising has come up, he needs the cath lab
     
  5. tum

    tum don't call it a comeback 10+ Year Member

    215
    11
    Mar 2, 2003
    maybe i read this over too quickly, but flattened t-waves? with a high k? is something off in denmark? i'm guessing the lab would have given you a heads up if there was some sort of hemolysis, but hey--you're at bellevue right? from what i've heard, anything can happen on 34th and 1st :)

    maybe i'm too much in test question mode, and with a widened QRS i'm not sure the shape of the t-waves really means so much, but .. with someone whose creatinine shows some sort of acute decompensation, a high potassium, but an ecg that shows delayed repolarization, i'd wonder if the beta blockers were being renally eliminated (ie corgard or what not), and he's having an acute overdose--that's only situation i'm aware of where you can have flat t's despite a high K. but maybe i just went hunting for unicorns because i feel like i just made that up. i'm gonna be an intern in 6 weeks--god help houston.

    interesting case.
     
  6. Phlegm

    Phlegm New Member 7+ Year Member

    30
    1
    Mar 16, 2005
    My initial thoughts similar to above:
    Presumptive Diagnosis: 1) Hyperkalemia 2) Possible cardiogenic shock 3) R/O hemorrhage (suspect pt receiving heparin, 2b3a, or plavix)

    What to do: Empiric tx as above for hyperkalemia while re-checking potassium. Also send ABG and Hgb. Would add empiric BiPAP while awaiting STAT TTE. Would be nice to know CVP or look at IVC with bedside echo. You could assume CVP high based on clinical scenario/presence of rales and start dopamine.
     
  7. Geri_Gal

    Geri_Gal Loving Life 2+ Year Member

    So what happened, PunjabiMD? Sounds like cardiogenic shock and that this guy needs his ABC's of resuscitation...but I'm intrigued with his ECG. Was the high K+ spurious?
     
  8. gordo244

    gordo244 Junior Member 7+ Year Member

    24
    0
    Jan 17, 2005
    Good case:

    I agree with the the above comments:
    ABC's
    Factitious K? needs to be ruled out
    What rx was he on?
    Pulm edma sounds evident
    Ruptured cordea s/p mi, prob too early? What about PE (of course i assume his on heparin or other)?
    arf - most likely pre-renal sec to cardiac decomp. GFR is zero with drop >1 in 24 hours.
    the last questions, and going along rta's, is what fluids was he getting and how much? was he getting KCL?? ns or 1/2 ns? plus, what was his admit creatinine?

    Need cxray, abg, repeat bmp and enzymes stat
    o2 via nc/nr/or bipap
    lasix iv
    echo asap

    working diagnosis:
    1. early shock, prob cardiogenic
    2. flash pulm edema
    3. arf (pre-renal sec to shock)

    fun case: whats the verdict
     

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