Recently we had a patient candidate for CABG who was alert and oriented. The first K after induction was 8 mEq/L. This number was confirmed by recheck. Two measurements on CPB were 6.5 (with low potassium cardiopledgia) and 7 (at the end of CPB). off pump K was 6.5 after giving insulin for BS=190 and NaHCO3 for acidosis (BE= -10). First postoperative K was 6.5 too. There was no EKG sign in perioperative period.
The patient had no Hx of renal problem with Cr=0.95 mg/dl. preop drug Hx included Aldacton 25 mg BD. however, last preop K was 4.8.
What's your opinion about this case?
There is reliable literature in the net describing severe hyperkalemia without ECG changes in certain cases. What is his/her creatinine, pH, HCO3? Check for enteral protein supplementation (containing high potassium) that may have been provided by others without your knowledge. Here's a reflective note on a similar patient:http://userdrivenhealthcare.blogspot.in/2008/12/case-based-reasoning-through-care.html regards,
rakesh
COI:
http://casereports.bmj.com/site/about/Biswas%20Rakesh.pdf, http://www.udhc.co.in/
http://www.igi-global.com/journal/international-journal-user-driven-healthcare/41022
http://www.linkedin.com/pub/rakesh-biswas/5/893/988
Probably the patient take antagonist of Angiotensin or an ARA II. The acidosis produce high K+, but really is false (no change in ECG) because change H+ for K+. If you resolved the acidosis K+ will go to decrease.
Patient of CAD for CABG , who was alert and oriented . pre op k was 4.8.with no H/O renal dysfunction. The first K after induction was 8 mEq/L.On CPB were 6.5 (with low potassium cardiopledgia) and 7 (at the end of CPB).off pump K was 6.5. First postoperative K was 6.5 too. There was no EKG sign in perioperative period.
Now few question arises
1. Which muscle relaxant was used for intubation - succinyl choline.
2.Any history of burn injury, paralysis or long time bed ridden or very old blood transfusion.
3.k infusion or injected by mistake.
4. Report error
The patient had no Hx of renal problem with Cr=0.95 mg/dl.
preop drug Hx included Aldacton 25 mg BD. however, last preop K was 4.8.What's your opinion about this case?
Arun
Tnx for your comments.
1. Pavulon as muscle relaxant
2. No burn no paralysis no long time hospital stay no transfusion
3. As far as I checked no k infusion
4. we rechecked the report 3 times the answers: 8, 8.1, 8.1
EKG changes are most useful in detecting dangerously high K+. However, EKG changes are complex and depend on many factors, e.g., pH (& resultant shift in ionized Calcium levels); ; [Na+], drugs (effects on ion channels in myocytes) etc. Of course, lab error and hemolysis are most common causes.
There is one study that shows: 'blinded' cardiologist were able to diagnose hyperkalemia in only something like less than 10% of patients with measured potassium of >5.5. Depend on the EKG only when is shows clear abnormality.
Would you note that study address. We have had many patients with K>5.5 without any ECG sign and without any problem after weaning and of course some patients with ECG sign for hyperkalemia. In this case there was no definite reason for hyperkalemia and simultaneous high BE (-10 to -12 mmol/L) which may explain in part such high level of K.
There are some possibilities I will take into consideration.
1. Typically only Iead II and V5 will be checked continuously during CABG, both of them may fail to find hyperK ECG signs. Typical hyperK ECG signs may occur in only some leads. How about 12-lead ECG after CABG?
2.Sternotomy and sternal spread during CABG could distort thoracic cage and change relative anatomical relationship between heart and ECG leads on the thoracic cage. Could sternal spread cloud typical hyperK ECG, making it less obvious?
3.Is it possible that existed ischemic ECG pattern mask typical ECG signs?
Dear Hsieh,
12-lead ECG was taken routinely in postoperative period and it was not so different. I agree that sternotomy changes the normal appearance of ECG especially the amplitude of the waves. However we expect its effect on T-wave be as same as the other parts (P, QRS, ST segment,...). I don't know whether some ischemic patterns hamper the ECG signs of hyperkalemia or not. Anyone knows? please comment.
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