What are the strategies for controlling hypertension in patients undergoing dialysis (Dialysis) for Impaired Renal Function?

From the Guidelines

Blood pressure management in dialysis patients requires a multifaceted approach combining fluid management, medication, and lifestyle modifications, with a focus on individualized care and patient-centered decision-making, as emphasized by the most recent Kidney Disease: Improving Global Outcomes (KDIGO) conference in 2020 1. The target blood pressure for most dialysis patients should be <140/90 mmHg before dialysis and <130/80 mmHg after dialysis. Key aspects of management include:

• Fluid management, with strict adherence to dry weight goals and sodium restriction (2-3g daily) being fundamental, as highlighted in the K/DOQI clinical practice guidelines for cardiovascular disease in dialysis patients 1.
• Pharmacological management, where long-acting calcium channel blockers like amlodipine and ACE inhibitors such as lisinopril are often first-line treatments, with beta-blockers like metoprolol being particularly beneficial for patients with heart failure or coronary artery disease.
• Lifestyle modifications, including regular physical activity, which has been associated with reductions in systolic and diastolic blood pressure, although barriers to exercise in dialysis patients must be addressed 1.
• Medication timing, with doses administered after dialysis sessions to prevent removal during treatment, and regular blood pressure monitoring, both at home and during dialysis sessions, with adjustments made based on these readings. This comprehensive approach is necessary because hypertension in dialysis patients stems from multiple factors, including volume overload, arterial stiffness, sympathetic overactivity, and renin-angiotensin system activation, making it particularly challenging to control. Recent studies, such as the 2020 KDIGO conference, emphasize the importance of individualizing dialysis prescriptions and incorporating patient preferences into decision-making to achieve optimal blood pressure and volume control 1. Additionally, the use of longer and/or more frequent dialysis sessions, as well as the implementation of 24-hour ambulatory blood pressure monitoring (ABPM), may be necessary to achieve control of blood pressure and fluid/volume status in many patients, although current reimbursement policies and patient resistance may render implementation difficult 1.

From the FDA Drug Label

Anaphylactoid Reactions During Dialysis Sudden and potentially life threatening anaphylactoid reactions have occurred in some patients dialyzed with high-flux membranes and treated concomitantly with an ACE inhibitor. In such patients, dialysis must be stopped immediately, and aggressive therapy for anaphylactoid reactions must be initiated Symptoms have not been relieved by antihistamines in these situations. In these patients, consideration should be given to using a different type of dialysis membrane or a different class of antihypertensive agent.

Blood Pressure Control with Dialysis Patients:

• The use of ACE inhibitors like lisinopril in dialysis patients may be associated with a risk of anaphylactoid reactions, particularly with high-flux membranes.
• Dose adjustment of lisinopril is required in patients undergoing hemodialysis or whose creatinine clearance is ≤ 30 mL/min 2.
• Consideration should be given to using a different type of dialysis membrane or a different class of antihypertensive agent in patients who experience anaphylactoid reactions.
• Patients at risk of excessive hypotension include those with the following conditions or characteristics: heart failure with systolic blood pressure below 100 mmHg, ischemic heart disease, cerebrovascular disease, hyponatremia, high dose diuretic therapy, renal dialysis, or severe volume and/or salt depletion of any etiology 2.
• Monitor renal function periodically in patients treated with lisinopril, especially in those whose renal function may depend in part on the activity of the renin-angiotensin system 2.

From the Research

Blood Pressure Control in Dialysis Patients

• Blood pressure control is crucial for dialysis patients, as they have a substantially increased risk of cardiovascular mortality and morbidity 3.
• Lowering blood pressure in dialysis patients has been shown to reduce the risk of cardiovascular events, all-cause mortality, and cardiovascular mortality 3.
• The optimal blood pressure target for dialysis patients is unknown, with observational studies showing poorer survival with predialysis blood pressure <140/90 mmHg 4.

Diagnosis and Mechanisms of Hypertension in Dialysis Patients

• Hypertension is very common in patients undergoing regular dialysis, with a prevalence of 70-80% 5.
• Interdialytic blood pressure, recorded as home blood pressure or by ambulatory blood pressure monitoring, associates more closely with mortality and cardiovascular events than predialytic blood pressure recordings 5.
• Volume excess is one of the factors mediating hypertension in dialysis patients, and aggressively challenging dry weight has been shown to reduce blood pressure but may increase the risk of vascular access thrombosis and intradialytic hypotension episodes 6, 4.

Management of Blood Pressure in Dialysis Patients

• Daily or prolonged nocturnal dialysis has been shown to lower blood pressure, but the extent to which this is due to enhanced solute clearance versus removal of excess volume is unclear 4.
• The use of bioimpedance or relative blood volume monitoring to guide fluid management has been tested in small studies, but more data are needed to determine its impact on clinical outcomes 4.
• Certain antihypertensive drugs, such as ACE inhibitors and calcium antagonists, have been shown to have vascular protective effects and may be useful in combination therapy for hypertension in dialysis patients 7.