What range of systolic blood pressure is considered hypotensive in a patient undergoing hemodialysis (HD) with aortic stenosis?

From the Guidelines

In patients undergoing hemodialysis with aortic stenosis, systolic blood pressure below 90-100 mmHg is generally considered hypotensive and requires immediate attention. This threshold is higher than for typical hemodialysis patients because those with aortic stenosis have reduced cardiac output capacity and are more vulnerable to hemodynamic instability 1. During hemodialysis, these patients require careful monitoring as the rapid fluid removal can precipitate dangerous hypotension.

Some key considerations for managing hypotension in these patients include:

• Slower ultrafiltration rates to avoid rapid fluid removal
• Careful dry weight assessment to prevent excessive fluid depletion
• Potentially setting a higher target blood pressure during treatment to maintain adequate cardiac output
• Preparedness to intervene quickly with volume expansion (saline bolus), Trendelenburg positioning, or even terminating the session early if hypotension develops in these high-risk patients.

It is essential to note that patients with aortic stenosis rely on adequate preload to maintain cardiac output across their stenotic valve, and hypotension can lead to coronary hypoperfusion, myocardial ischemia, and even sudden cardiac death 1. The management strategy should prioritize maintaining a stable blood pressure to ensure optimal cardiac output and prevent complications.

In the context of hemodialysis, controlling blood pressure through dietary sodium restriction and appropriate ultrafiltration is crucial, as evidenced by studies showing improved blood pressure control and regression of left ventricular hypertrophy with these strategies 1. However, the presence of aortic stenosis necessitates a more cautious approach to fluid management and blood pressure control to avoid hypotension and its associated risks.

From the Research

Hypotensive Blood Pressure Range in Hemodialysis Patients with Aortic Stenosis

• The definition of hypotension can vary, but in the context of hemodialysis, a systolic blood pressure < 100 mmHg in the interdialytic period is considered chronic hypotension 2.
• A study on midodrine treatment for patients with hemodialysis hypotension reported a significant increase in minimal systolic pressure from 93.1 mmHg to 107.1 mmHg during hemodialysis 3.
• Another study reported that the lowest intra- and post-dialysis blood pressures were monitored, with a fall of > or = 30 mmHg in systolic blood pressure with associated clinical symptoms during hemodialysis 3.
• In a case report on the use of fludrocortisone for intradialytic hypotension, systolic blood pressure became lower than 80 mmHg more frequently in sessions without fludrocortisone administration than in sessions with fludrocortisone administration 4.
• A study on nitroprusside in critically ill patients with left ventricular dysfunction and aortic stenosis excluded patients with hypotension, defined as a mean systemic arterial pressure < 60 mm Hg 5.

Systolic Blood Pressure Targets

• Observational evidence suggests that systolic blood pressure values between 130 and 139 mmHg might represent the best option for patients with aortic stenosis, and lower blood pressure targets should probably be avoided 6.
• However, in the context of hemodialysis, the target systolic blood pressure may be higher, around 100-120 mmHg, to avoid hypotension and its associated complications 3, 2.