A drop in blood pressure is a common complication during hemodialysis. In medical jargon, the phenomenon is called intra-dialytic hypotension. It can be a debilitating problem, as it often requires cutting dialysis treatments short, leading to inadequate dialysis therapy. It can also lead to the excess fluid being left, which is associated with a higher risk of death in patients receiving dialysis.

Risk Factors

Research and observations from medical professionals seem to indicate that some patients are more likely to experience drops in blood pressure related to dialysis treatment. In a study from 2017, researchers observed that patients with sepsis and obstructive kidney disease seemed more likely to develop hypotension.

Other possible risk factors for experiencing a drop in blood pressure while receiving dialysis include:

  • Older patients
  • Patients who have been on dialysis for a long time
  • People with diabetes
  • Female patients
  • Obese patients
  • Patients requiring an excessively high amount of fluid removal, or ultrafiltration, because of a high inter-dialytic weight gain
  • Patients with a dry weight that is too low
  • Taking blood pressure medications just prior to dialysis
  • Eating meals during dialysis

While the exact cause is unclear, everything from nerve disease caused by diabetes (autonomic neuropathy) to rapid fluid removal during dialysis has been proposed as an explanation for intradialytic hypotension.

There are also less common but more serious causes of hypotension associated with dialysis such as infections, abnormal heart rhythms, and even heart attacks.

Signs and Symptoms

Intradialytic hypotension manifests as a rapid, and obvious, drop in blood pressure, but there are other subjective symptoms. Patients will often complain of muscle cramps, back, chest, or abdominal pain, headaches, nausea, and lightheadedness. The associated vagal nerve stimulation can also cause yawning and sighing.

Treatment

Intradialytic hypotension can be challenging to treat, especially in patients with multiple risk factors.

The dialysis staff will reduce or even stop fluid removal completely during this period. You might be reclined in a specific position (Trendelenburg) to increase the blood flow to the brain. However, medical professionals debate how useful the position is for treating intradialytic hypotension.

For most patients who experience a drop in blood pressure, small amounts of intravenous fluids are given (usually a common fluid-like normal saline given in a small bolus of 250 ml or so).

In some cases, a medication called midodrine is used as a last resort. Research has shown that while it might offer short-term benefits for some patients, long-term use comes with risks and some patients don’t see any benefit at all.

Prevention

The underlying risk factors need to be identified and addressed in each patient who experiences a drop in blood pressure while receiving dialysis.

The recommendations will depend on an individual patient’s needs and risk factors, but may include:

  • Avoiding meals during dialysisAvoid taking blood pressure medications just prior to dialysis or consider switching timesAvoiding weight gain between successive dialysis treatment, as the less fluid that needs to be removed, the easier it is for the circulatory system to maintain blood pressure.

If you’re complying with your prescribed fluid regimen and have no other risk factors, your healthcare provider might refer you to a cardiologist or have you get an echocardiogram, as the heart can be a cause of drops in blood pressure.

Your nephrologist might prescribe dialysis differently, such as with a higher amount of sodium. If these measures fail, you may need to increase your dry weight.

If nothing else works and the problem is recurrent, your healthcare provider might suggest peritoneal dialysis or home hemodialysis.