Management of Hyperkalemia

Hyperkalemia

1. Management of Hyperkalemia Randolph Tulsie

2. Lets Start with a Case of Mr D.S A 77 year old Male referred from a Nursing H ome C/C= Dehydration and Unresponsiveness x 3/7 The patient had new onset unresponsiveness with generalized weakness. Associated with LOA and oliguria. No fevers, Vomits or Diarrhea . No slurred speech, unilateral weakness or stroke like symptoms related by accompanying nurse. PMHx = Hypertensive x 20 years, No DM or CVA PSHx =nil SHx = unknown Drug Hx = Tabs ASA, Amlopidine , Atorvastatin Allergies = unknown History

3. A Case of Dehydration and Unresponsiveness Physical Exam Vitals PR 130 RR 20 BP 90/50 SpO2 96% RA General- Patient was seen lying in bed in no obvious CP or Painful Distress HEENT Eyes – PEARL, Sclera anicteric MM – Dry and Pink Oral – Cracked Lips with hyper keratinous lesion seen to lower lip RESP – BAE clear x 2 CVS - S1 S2 M0 Tachycardia, Regular Rhythm ABD – Benign EXT – NROM x 4, Grade 2/5 Weakness x 4, Dry Cracked Skin, Decreased Skin Turgor CNS – GCS 9/15 E4 V2 M3

4. Initial Workup Hb WBC PLT 12.1 11.6 214 IMP: 77 y/o Male, PHMx of Hypertension presenting with signs of S evere D ehydration and Serum Electrolyte Imbalance; Hypernatremia and Hyperkalemia secondary to AKI vs CKD . NA CL BUN 154.3 112.5 74 K CR 6.21 4.5 U/A Increased Specific Gravity, No ketones, Neg Nitrites, No RBS or WBC CXR NO Infiltrates RBS 112mg/dl Bedside U/S Flat IVC

5. HYPERKALEMIA Physiology and Causes Evaluation and Clinical Manifestations Acute Management Chronic Management

6. A bit on Potassium Physiology … P otassium is primarily an intracellular cation, with the cells containing approximately 98 percent of body potassium. The intracellular potassium concentration is approximately 140  meq /L compared with 4 to 5  meq /L in the extracellular fluid.  This potassium gradient is maintained by the Na-K-ATPase pump in the cell membrane, which pumps sodium out of and potassium into the cell in a 3:2 ratio .

7. What is Hyperkalemia ?

8. Causes of Hyperkalemia

9. Evaluation of Hyperkalemia Evaluation of the patient with hyperkalemia usually begins with a careful history , evaluation for clinical manifestations of hyperkalemia such as muscle weakness and characteristic changes on the electrocardiogram, and laboratory testing for the causes of hyperkalemia  Examine medications and hold hyperK causing meds

10. Clinical Manifestations The most serious manifestations of hyperkalemia are muscle weakness or paralysis, cardiac conduction abnormalities, and cardiac arrhythmias. Usually present when the serum potassium concentration is  ≥7.0  mEq /L  with chronic hyperkalemia or possibly at lower levels with an acute rise in serum potassium .

11. ECG Changes Tall peaked T waves with a shortened QT interval are usually the first findings. As the hyperkalemia gets more severe, there is progressive lengthening of the PR interval and QRS duration, the P wave may disappear and ultimately the QRS widens further to a sine wave pattern Ventricular standstill with a flat line on the ECG ensues with complete absence of electrical activity.

12. The Evidence on Hyperkalemia ECG Findings An ECG is a poor tool for detecting Hyperkalemia (Low sensitivity) however, if characteristic hyperK changes are seen; HyperK is likely. (Good Specificity) One study, found T wave abnormalities were present in only 39 percent of patients with potassium of 7 to 9 mEq /L. The 14 patients with damaging arrhythmias or cardiac arrest only had EKG changes about 50 percent of the time  [ Montague Clin J Am Soc Neph 2008 – PMID18235147 ]. A study of dialysis patients found no relationship between T wave amplitude and hyperkalemia [ Aslam Nephro Dial Transp 2002 – PMID12198216 ]. BOTTOM LINE: DO NOT HOLD RX BECAUSE ECG IS NORMAL

13. Acute Treatment of Hyperkalemia Hyperkalemic emergency The following patients require immediate reduction in serum potassium levels: Patients who have clinical signs or symptoms of hyperkalemia; Paralysis or Muscle Weakness with Hyperkalemia Patients with severe hyperkalemia (especially with concurrent tissue breakdown ( Tumor Lysis Syndrome, GI bleeds) Some patients with moderate hyperkalemia (>5.5  mEq /L)  and Significant Renal Impairment or a significant non-anion gap metabolic acidosis or respiratory acidosis .

14. Acute Management of Hyperkalemia Emergency

15. Acute Management of Hyperkalemia Emergency

16. Non Emergent Hyperkalemia Patients with mild to moderate hyperkalemia without Renal Impairment can be managed as follows Stop Any Medications which can cause Hyperkalemia (ACEI, ARBs, Septrin ) Dietary Counselling; avoid dyed fruits, nuts, avocados, tomato juice, ground meat and bananas Loop Diuretics Kayexalate

17. References UpToDate Medical Library – Hyperkalemia The Curbsiders Internal Medicine Podcast – Hyperkalemia Masterclass Harrison’s Principles of Internal Medicine 19 th Ed