Emergency Dialysis - Indications and Procedure

Introduction

The kidneys are vital organs that filter the blood, remove wastes and excess acid, electrolytes, and fluid, and pass them out in the urine. If kidneys do not work properly (as seen in advanced renal failure or poisoning), they do not filter the blood efficiently. This results in the body's waste build-up, leading to life-threatening symptoms and conditions. In dialysis, the patient’s blood is passed through a machine that functions like a kidney and cleans up the blood. This procedure helps to remove excess waste products, acids, electrolytes, toxins, and fluid from the blood. Emergency dialysis is usually performed during acute kidney injury or failure that occurs suddenly within a few hours or days.

When Is Emergency Dialysis Performed?

If the kidneys fail or are damaged suddenly, cleaning the blood and maintaining the right fluid balance becomes hard. It eventually affects other vital organs, such as the heart, lungs, and brain. Emergency acute renal replacement therapy (urgent dialysis) is done when the patient’s condition is refractory to conventional therapy. Dialysis is performed when the patient loses about 85 to 90 percent of kidney function (glomerular filtration rate less than 15). Dialysis is performed until the kidneys recover. The indications for urgent dialysis include the following:

1. Acid-base imbalance in the body, such as severe metabolic acidosis (when the acid level in the body is too high).

2. Electrolyte imbalances require emergency management, such as increased blood potassium levels (life-threatening hyperkalemia) or abnormally high blood calcium levels.

3. Intoxication with drugs and alcohol (methanol, lithium, ethylene glycol, salicylates).

4. Abnormally high waste products in the blood (uremia affecting the heart and brain function).

5. Decreased blood flow to the kidneys due to diseases and conditions such as severe burns, injury, bleeding, or allergy.

6. Conditions causing direct damage to the kidney.

7. Blood clots, stones, or tumors (blocking the urinary tract).

What Are the Warning Signs That Indicate the Need for Emergency Dialysis?

Emergency dialysis may be required by patients with chronic kidney disease (uncontrolled), intensive care unit patients, and critically ill emergency patients. Acute kidney failure's warning signs and symptoms depend on the cause and the organ affected (heart, lungs, or brain). Some cases do not have any obvious symptoms or signs, and the healthcare provider identifies the need to perform dialysis through blood tests. However, the warning signs requiring emergency dialysis include the following:

• Too little urine (decreased urine output).

• Swelling in ankles, legs, and around eyes.

• Tiredness or fatigue.

• Breathing difficulties.

• Confusion.

• Seizures.

• Coma.

• Nausea.

• Chest pain, discomfort, or pressure.

What Are the Various Tests to Assess Kidney Function Requiring Urgent Dialysis?

The healthcare provider performs different tests to check for acute kidney injury and failure. These include:

1. Urine output.

2. Urine tests to assess kidney function.

3. Blood tests include:

   • Urea level.

   • Creatinine level.

   • Nitrogen and phosphorus levels.

   • Blood electrolyte levels (sodium, potassium, calcium).

   • Bicarbonate level.

   • Other kidney function tests.

   • Glomerular filtration rate to check for kidney function.

4. Imaging tests such as ultrasound to view the kidneys and urinary tract.

What Is the Commonly Used Access in Emergency Dialysis?

The blood from the patient is transported to a machine that performs the dialysis through a tube. So patients need access placed in their bodies to enable blood to be efficiently sent to the dialysis machine. There are several types of dialysis access, including a central venous catheter, arteriovenous fistula or graft, and a peritoneal dialysis catheter.

• Central Venous Catheter: It is the most common access for emergency dialysis. This is temporary access, in which a long y-shaped tube or catheter (made of flexible plastic) is inserted into the large vein in the neck, chest, or groin. Central venous catheters can be quickly placed and removed. However, care should be taken while using these catheters as they can get infected or damage the central vein.

How Is Emergency Dialysis Performed?

• Central venous access is obtained for emergency dialysis.

• During dialysis, the patients are made to sit or recline in a chair (if they are stable enough). The stable patients can nap, watch a movie, read or talk during the procedure. If unstable, they are positioned as required for the procedure, depending on the patient’s condition.

• The patient’s vitals, weight, blood pressure, and temperature are checked before the procedure. The skin covering the access site is prepared and cleaned. The blood leaves and reenters the body through the access site, so proper sterilization technique is essential.

• Two needles are inserted into the access and secured. Each of these needles is attached to a flexible plastic tube. One tube carries the patient’s blood (with toxic waste products, abnormal amounts of acids, and electrolytes) and passes it to the dialysis machine (dialyzer). The dialysis machine removes the excess wastes from the blood during the dialysis procedure. The blood is filtered a few ounces at a time. The second tube carries the filtered blood from the dialysis machine back to the patient’s body.

• The patients may experience nausea or abdominal cramps (as excess fluid is removed). The speed of the procedure, medications, and dialysis fluids may be adjusted to minimize such unpleasant symptoms. The patient's blood pressure and heart rate can fluctuate as the excess electrolytes and fluids are removed from the body. Thus, healthcare professionals carefully monitor the patient's vitals, heart rate, and blood pressure during the procedure.

• Once the emergency dialysis is completed, the needles are removed, and a pressure dressing is applied to the access site (to prevent bleeding). The patient's vitals are re-recorded after the procedure.

Conclusion

In dialysis, the patient’s blood is passed through a machine that functions like a kidney and cleans up the blood. Emergency dialysis helps remove excess waste products, acids, electrolytes, toxins, and fluid from the blood. If emergency dialysis is performed due to sudden or acute kidney injury, dialysis is required only for a short time (until the kidneys recover). However, if the patient had a history of decreased kidney function before the acute kidney failure, the patient might require routine dialysis to maintain a healthy life.