Quick 5 questions: help you sort out your knowledge of diagnosis and treatment of hyperkalemia

Hyperkalemia is a common acute electrolyte abnormality in clinical practice, which can lead to serious complications and life-threatening arrhythmia, requiring rapid intervention.

Hyperkalemia is not common in the general population, but is more common in patients with susceptible diseases such as chronic kidney disease, diabetes, and heart failure.

For example, the prevalence of hypokalemia in Chinese peritoneal dialysis patients is 20.
3%-27.
9%.

Question 1: Regarding the examination of hyperkalemia, which statement is accurate? A.
Measuring the transrenal potassium concentration gradient (TTKG) is an accurate method to assess the effect of reduced renal excretion on hyperkalemia.
B.
Patients with renal failure should check the serum calcium level.
C.
It is recommended for all patients with elevated serum potassium levels.
Perform arterial or venous blood gas analysis.
D.
Hyperkalemia symptoms are reliably related to blood potassium levels.
Correct answer: B Analysis: TTKG measurement is often used to assess whether decreased renal potassium excretion leads to hyperkalemia, but it is only effective under the following conditions: (1) The urine osmolality is greater than the serum osmolality (that is, the urine is concentrated for serum); (2) urine sodium>20mEq/L.

Recent data indicate that the urea cycle may affect the secretion of potassium, which also raises some questions about the utility of the TTKG measurement in this situation.

 Renal function testing is very important in the examination of hyperkalemia.

In patients with renal failure, blood calcium should be evaluated, because hypocalcemia can aggravate arrhythmia.

 If acidosis is suspected, an arterial or venous blood gas analysis can be performed.

However, the initial auxiliary tests usually include renal function tests, electrocardiogram, urine potassium, sodium, creatinine, and osmolality.

 There is no reliable correlation between the symptoms of hyperkalemia and serum potassium levels.

 Question 2: Regarding the ECG examination of patients with hyperkalemia, which of the following is correct? A.
ECG performance has nothing to do with blood potassium levels B.
Prolonged PR interval is an early signal of hyperkalemia C.
Hyperkalemia does not see QRS complex time extension D.
The ECG results of patients with chronic hyperkalemia may be relatively normal Correct answer: D Analysis: The growth rate of blood potassium is more clinically significant than blood potassium levels.

Even at high potassium levels, the electrocardiogram of patients with chronic hyperkalemia may be relatively normal.

On the contrary, a sharp increase in serum potassium may cause significant changes in the electrocardiogram of patients with relatively low serum potassium.

In addition, less than 50% of patients with hyperkalemia with typical ECG manifestations in clinical practice, so some patients with hyperkalemia may have relatively normal ECG results.

 Clinicians need to keep in mind that although the electrocardiogram of patients with hyperkalemia is related to blood potassium levels, almost any level of hyperkalemia can cause life-threatening arrhythmias without warning.

In patients with organic heart disease and abnormal baseline ECG, bradycardia may be the only new abnormality.

 The early ECG changes of hyperkalemia include high sharp T waves (more pronounced in the precordial leads), shortened QT interval, and ST segment depression.

In most cases, these changes are visible when the blood potassium level is 5.
5-6.
5 mEq/L.

 Question 3: For patients with moderately elevated blood potassium levels and no ECG abnormalities, which initial treatment should be considered? A.
Intravenous insulin-glucose B.
Cation exchange resin or diuretics C.
Calcium or hypertonic sodium solution D.
Loop diuretics or thiazide diuretics Correct answer: B Analysis: For moderately elevated potassium levels without electrocardiogram In abnormal patients, cation exchange resins or diuretics are the first choice to increase potassium excretion.

In addition, the source of excess potassium must be corrected, such as increased intake or decreased excretion.

 Question 4: Regarding the treatment of hyperkalemia, which statement is accurate? A.
If a patient is suspected of digitalis poisoning, magnesium sulfate and calcium should be avoided.
B.
Potassium-containing drugs need not be stopped.
C.
After diagnosis and After the treatment of hyperkalemia, the patient's blood potassium should be monitored, and the potassium level should be measured at least once 1, 2, 4, 6 and 24 hours after the start of treatment.
D.
Intravenous infusion of glucose and insulin cannot effectively increase the absorption of potassium.
Correct answer : C Analysis: It is recommended to measure potassium levels at least 1, 2, 4, 6 and 24 hours after recognizing and treating hyperkalemia.

 Patients suspected of digoxin poisoning should avoid intravenous calcium-containing solutions.
Magnesium sulfate can be used for patients with arrhythmia caused by digoxin poisoning.

 The use of potassium-sparing drugs and dietary potassium should be stopped, including parenteral potassium supplements and potassium-containing salt substitutes.

 Insulin and glucose are injected intravenously.
Patients with hyperglycemia can use insulin alone to introduce potassium ions into the cells, thereby effectively reducing blood potassium.

The usual plan is to add 10 units of insulin to 50ml of 50% glucose solution.

The use of insulin must be closely monitored for hypoglycemia.

 Question 5: Regarding the treatment of hyperkalemia after kidney transplantation, which statement is accurate? A.
When β2 agonists are used in combination with loop diuretics or thiazide diuretics, a synergistic effect may lead to a decrease in blood potassium B.
For patients whose estimated glomerular filtration rate (eGFR) is less than 45mL/min/1.
73㎡, thiazide diuretics are better than loop diuretics.
C.
Cation exchangers are superior in critical and critical cases of hyperkalemia In hemodialysis D.
When the patient’s blood potassium is more than 5.
5mEq/L, treatment to stabilize the myocardium should be given.
Correct answer: A Analysis: When β2 agonists are used in combination with loop diuretics or thiazides, a combined effect may occur.
Thereby lowering the patient's blood potassium.

In addition, adding a β2 receptor agonist to the nebulizer can quickly reduce blood potassium levels for a short period of time.

However, within a few minutes after inhaling salbutamol, the blood potassium level will rise abnormally, which requires the attention of clinicians.

 For patients with eGFR<45mL/min/1.
73㎡, most thiazide diuretics have poor efficacy, and loop diuretics should be used.  In the acute and critical condition of hyperkalemia, hemodialysis is superior to cation exchangers.

Cation exchangers are only used when dialysis is not possible, and once the patient is able to dialysis, he needs to switch to dialysis therapy immediately.

 If the electrocardiogram has obvious abnormal changes or the blood potassium is more than 6.
5mEq/L, intravenous calcium should be used to stabilize the myocardium.

In addition, calcium gluconate is less irritating to veins, and peripheral intravenous injection can be used.
However, large doses of calcium chloride may cause tissue necrosis, so central intravenous drip is required.

Calcium should be used with caution in patients using digitalis preparations, because hypercalcemia may aggravate the toxic effect on the myocardium.

 References: 1.
A.
Brent Alper.
Fast Five Quiz: Hyperkalemia Management.
Medscape.
April 09 2021.
2.
Chinese Medical Association Nephrology Branch Expert Group.
Expert consensus on blood potassium management in patients with chronic kidney disease in China.
Chinese Journal of Nephrology.
2020 10.