Putting The K in EKG

HPI: 
Patient is a 50 yo F with a history of ESRD s/p failed renal transplant now on hemodialysis who had onset of GI bleeding with associated lightheadedness and hypotension. An EKG was obtained. 

EKG:

Question: 
What finding on this EKG warrants further management? 

EKG Interpretation: 
Normal sinus rhythm at a rate of 77, normal PR interval, normal QRS, normal axis, LVH (significantly increased voltages), narrow based, peaked T-waves, T-wave inversions in leads III and aVF. 

Discussion:
The narrow based, peaked T-waves present in this patient’s EKG, most evident in leads V3-V4, indicate probable hyperkalemia in this patient who is at risk for elevated potassium given her ESRD. The T-wave abnormalities in this EKG are somewhat subtle, but the narrow, “pinched down” bases of the T-waves should warn you of hyperkalemia. This patient’s potassium level was found to be 6.9 and was appropriately treated.

Pro-tip: 

• Lead V4 can be your best friend for visualizing a lot of pathology on EKGs, including hyperkalemia, so make sure you pay attention to that upper right corner for subtle signs of elevated potassium! 
  
• Remember to compare to an old EKG if available. 
  
• Post treatment EKG shows much smaller, more typical broad based T waves:
  

Potassium can be the great imitator on EKGs because it can cause a wide variety of abnormal EKG findings, including (but not limited to):
• Peaked T-waves (often the earliest EKG sign of hyperkalemia)
• Prolonged PR interval
• Loss of P waves
• AV block
• Broad QRS complexes with abnormal morphology
• Sine waves (usually with extremely severe hyperkalemia)

Management:
For patients with ESRD on hemodialysis, dialysis is the definitive treatment for hyperkalemia. 
Typical management of hyperkalemia (for K>6.0 or EKG changes) includes**:
• Calcium (either IV calcium gluconate or calcium chloride), which stabilizes cellular membranes by antagonizing the effect of potassium on membrane potential. Usually reserved for K>7.0 or EKG changes. 
• Insulin to promote the movement of potassium into cells.
• Albuterol and Sodium bicarbonate can also be used to promote the movement of potassium into cells depending on potassium levels.
• Kayexalate (Sodium polystyrene sulfonate) can be used to promote potassium elimination from the body, however this has no role in the acute management of hyperkalemia with EKG changes.
**Caution in patients with DKA because total body potassium may actually be low and aggressive management of hyperkalemia can result in hypokalemia**

By: Krystin Thomas, PGY1

Resources:
• Stone, CK. Fluid, Electrolyte, and Acid-Base Emergencies. In Current diagnosis & treatment emergency medicine. 6th ed. New York: McGraw-Hill; 2008. 
• Burns, E. Hyperkalemia [Web log post] Retrieved August 28, 2015, from http://lifeinthefastlane.com/ecg-library/basics/hyperkalaemia/