Blood Pressure Management in Stage G4 CKD (eGFR 17 mL/min/1.73 m²)
Target systolic blood pressure <120 mm Hg to slow CKD progression and reduce cardiovascular mortality, using ACE inhibitors or ARBs as first-line therapy if albuminuria is present. 1
Blood Pressure Target
Aim for systolic blood pressure <120 mm Hg rather than the traditional <140/90 mm Hg target, as intensive blood pressure lowering has been shown to attenuate CKD progression even at advanced stages. 1
The Canadian Society of Nephrology recommends a target of 140/90 mm Hg regardless of diabetes or proteinuria status 2, but this represents older guidance (2015) that has been superseded by more recent evidence supporting intensive targets.
Intensive BP lowering is safe even if serum creatinine rises up to 30% from baseline, provided the patient maintains adequate volume status and the rise stabilizes. 1
In the SPRINT CKD subgroup analysis, patients with eGFR 20-60 mL/min/1.73 m² randomized to systolic BP <120 mm Hg showed a hazard ratio of 0.81 (95% CI 0.63-1.05) for cardiovascular events and 0.72 (95% CI 0.53-0.99) for death compared to <140 mm Hg target. 2
First-Line Antihypertensive Selection
ACE inhibitors or ARBs at maximally tolerated doses should be the foundation of therapy when albuminuria ≥300 mg/g is present, as they provide both blood pressure control and renoprotection. 2, 1
If albuminuria is present at any level, ACE inhibitor or ARB therapy is advised to slow progression and reduce cardiovascular risk. 1
Do not combine ACE inhibitors with ARBs, as this dual blockade increases adverse events without additional benefit. 2
Continue ACE inhibitor or ARB therapy even if creatinine rises ≤30% after initiation, unless there is evidence of volume depletion or acute kidney injury from another cause. 2
Additional Antihypertensive Agents
Dihydropyridine calcium channel blockers or diuretics can be added as second-line agents when ACE inhibitor/ARB monotherapy does not achieve target BP. 2
At eGFR 17 mL/min/1.73 m², loop diuretics (furosemide or torsemide) are preferred over thiazides for volume management, as thiazides lose efficacy below eGFR 30 mL/min/1.73 m². 1
All three classes (ACE inhibitor/ARB, calcium channel blocker, and diuretic) are often needed to attain BP targets in advanced CKD. 2
Monitoring and Safety
Check serum potassium and creatinine within 1-2 weeks after initiating or up-titrating ACE inhibitor/ARB therapy to detect hyperkalemia or excessive creatinine rise. 1, 3
Monitor blood pressure at every visit and adjust medications to maintain systolic BP <120 mm Hg consistently. 1
Assess volume status clinically before attributing creatinine rises to medication effects; volume depletion from over-diuresis can mimic hemodynamic effects of RAS blockade. 1
Common Pitfalls to Avoid
Do not discontinue ACE inhibitor/ARB prematurely for modest creatinine rises (<30%); this removes critical renoprotection and cardiovascular benefit. 2, 1
Avoid NSAIDs completely, as they reduce renal blood flow, blunt the effectiveness of antihypertensives, and can precipitate acute-on-chronic kidney injury. 1, 3
Do not use potassium-sparing diuretics (spironolactone, amiloride) or nonsteroidal mineralocorticoid receptor antagonists (finerenone) at eGFR 17 mL/min/1.73 m², as finerenone is only recommended when eGFR ≥25 mL/min/1.73 m² and hyperkalemia risk is prohibitive at this level of kidney function. 2, 1
Verify all medication doses for renal adjustment at eGFR <30 mL/min/1.73 m², as many antihypertensives and other drugs require dose reduction or discontinuation. 1, 3
Adjunctive Measures
Restrict dietary sodium to <2 g/day to enhance blood pressure control and maximize diuretic effectiveness. 1, 3
Limit dietary protein to ≤0.8 g/kg/day to reduce hyperfiltration injury and slow progression. 1, 3
Ensure nephrology referral has occurred, as eGFR <30 mL/min/1.73 m² mandates specialist involvement for pre-dialysis education, access planning, and optimization of medical management. 1