Hypotension during hemodialysis: role for nitric oxide

Area of Science:

• Nephrology
• Cardiovascular Physiology
• Biochemistry

Background:

• Hypotensive episodes are common during hemodialysis for end-stage renal disease (ESRD).
• Nitric oxide (NO) is a key regulator of cardiovascular hemodynamics.
• The role of NO in dialysis-induced hypotension is not fully understood.

Purpose of the Study:

• To investigate the potential involvement of nitric oxide (NO) in hypotensive episodes experienced by patients undergoing hemodialysis.
• To analyze the levels of nitrite + nitrate (NO2 + NO3), stable end products of NO, in ESRD patients before and after dialysis.

Main Methods:

• Plasma samples from 17 hemodialysis patients and 9 controls were analyzed for NO2 + NO3 using the Greiss method.
• Patients were categorized into two groups based on their NO2 + NO3 reduction ratio during dialysis.
• Blood pressure, skin, and core temperatures were monitored.

Main Results:

• Predialysis NO2 + NO3 levels were significantly higher in ESRD patients compared to controls.
• In one group (Group B), NO2 + NO3 levels increased post-dialysis, unlike the other group (Group A) where levels decreased.
• Group B exhibited significantly greater reductions in systolic blood pressure and lower temperatures compared to Group A.

Conclusions:

• Increased nitric oxide (NO) synthesis during hemodialysis may contribute to hypotensive episodes in a subset of ESRD patients.
• The findings suggest a significant role for NO in the pathophysiology of dialysis-induced hypotension.
• Further research is needed to elucidate the basis for differential NO production during hemodialysis.