welcome to week 2

This week, we’ll be talking about two common electrolyte disorders as well as diving into renal replacement therapy in the hospital. These are all exciting topics and contain information you’ll frequently use for years to come.

Table of Contents

1. Evaluation and Management of Potassium Disorders

2. Evaluation and Management of Sodium Disorders

3. When and How to do Renal Replacement Therapy in the Hospital

Evaluation and Management of Potassium Disorders

Hypokalemia and Hyperkalemia are common electrolyte disorders that you will see frequently. To start, read the K+ eval/management page here. Next, if you want to read some excellent case presentations by true experts, read these Renal Fellow Network posts by The Skeleton Group below:

Skeleton Key Group Case on hypokalemia

Skeleton key group case on hyperkalemia

Quiz Questions

1. Name two causes of pseudohyperkalemia. 

2. Name 5 medications that can cause hyperkalemia. 

3. What are indications to give rapid-acting medications for hyperkalemia? If you have a patient with hyperkalemia who needs rapid-acting medications, which medications will you give?

4. What dreaded complication is associated with Kayexalate?

5. What electrolyte abnormality can cause hypokalemia?

6. Lastly (although this was not covered in required reading), if you have a patient in the hospital with normal kidney function and a potassium level of 3.2 mmol/L, how much potassium would you need to give to correct their potassium to 4.0mmol/L. 

7. If the same patient from above had a potassium of 2.8mmol/L, now much potassium would you need to give to correct them to a potassium of 4.0mmol/L?

Evaluation and Management of Sodium Disorders

Magnesium may be the forgotten electrolyte, but sodium certainly isn’t. In fact, hyponatremia is the most common electrolyte disorder in the hospital. As such, it’s good to get a head start on learning how to manage sodium disorders now, because it’s only a (short) matter of time before you encounter it. Start with reading the page on sodium disorders here. Next, if you want to really get good at hyponatremia, read the 2013 American Journal of Medicine review article by Verbalis. Yes, it’s a 42 page review article on hyponaremia (which could be considered cruel ad unusual punishment), but it’s open source and honestly a gift to the world. It outlines the evaluation of hyponatremia in a simple manner. It’s also been cited an astonishing 770 times which is warranted given it’s usefulness. After this, take a look at the Skeleton Key Group Cases on sodium disorders below. Lastly, just know that the rate of correction of hypERnatremia has received attention lately. Read the NephJC write up on a 2019 NephJC paper on this subject below.

Skeleton Key Group Case on Hyponatremia

Skeleton Key Group Case on Hypernatremia

NephJC Summary of Hypernatremia Correction

Quiz Questions

1. What type of sodium disorder is characterized by a low serum sodium, but a normal serum osmolality (280-295 mOsm/kg)?

2. What is the treatment for a hyponatremic patient with active seizures?

3. What medication can you use to stop urinary free water loss and stabilize a rising sodium level or even relower it?

4. If you get an admission from the ED for a patient with hyponatremia with a serum sodium level of  119mmol/L, what tests do you order and what physical exam findings are most important?

5. Do loop diuretics cause hyponatremia?

When and How to Do Renal Replacement Therapy in the Hospital

This is obviously one of the important aspects of a nephrology consult service. It is important to know what types of renal replacement therapy we provide in the hospital, how they work, and when we start it. Read this write up to learn more.

Quiz Questions

1. What are the three main mechanisms by which renal replacement therapy cleans the blood and removes fluid?

2. What are two reasons that we would perform continuous renal replacement therapy instead of intermittent hemodialysis?

3. How does peritoneal dialysis achieve ultrafiltration and remove fluid from the body?

4. What’s an advantage of intermittent hemodialysis over continuous renal replacement therapy?

5. What are the indications for hemodialysis?