What is the appropriate management for a 17-year-old patient with hypertension, proteinuria, and impaired renal function?

Management of a 17-Year-Old with Hypertension, Proteinuria, and Impaired Renal Function

This adolescent requires immediate initiation of an ACE inhibitor or ARB at maximum tolerated doses, targeting blood pressure <120 mmHg systolic (or 50th percentile for age/sex/height on 24-hour ambulatory monitoring), with urgent nephrology referral to determine the underlying cause of glomerular disease. 1

Immediate Diagnostic Workup

Quantify Proteinuria Properly

• The random urine protein-to-creatinine ratio of 9 mg/mg (protein <4 mg/dL, creatinine random) suggests significant proteinuria requiring confirmation with either a 24-hour urine collection or a properly calculated spot urine protein-to-creatinine ratio 1, 2
• A protein-to-creatinine ratio >0.2 mg/mg is abnormal; this patient's value of 9 mg/mg indicates nephrotic-range proteinuria (>3 g/day equivalent) 1, 3

Calculate eGFR and Stage Kidney Disease

• Calculate estimated GFR using the CKD-EPI equation (race-free version) to determine the severity of renal impairment 2, 1
• Serum creatinine alone is insufficient; eGFR <60 mL/min/1.73 m² defines chronic kidney disease 1, 2

Examine Urine Sediment

• Perform urinalysis with microscopy immediately to distinguish between glomerulonephritis (dysmorphic RBCs, RBC casts, acanthocytes >5%) versus hypertensive nephrosclerosis (bland sediment) 1, 2
• The presence of active sediment in a 17-year-old with this degree of proteinuria strongly suggests primary glomerular disease rather than hypertensive nephrosclerosis alone 4

Additional Laboratory Tests

• Measure serum electrolytes (particularly potassium), albumin, lipid panel, complement levels (C3, C4), ANA, anti-dsDNA, ANCA, hepatitis B/C serologies, and HIV testing 4
• Obtain renal ultrasound with Doppler to assess kidney size, echogenicity, and exclude structural abnormalities or renovascular disease 2

Urgent Nephrology Referral Criteria Met

This patient meets multiple criteria for immediate nephrology referral: 2

• Significant proteinuria (likely nephrotic range)
• Renal impairment in an adolescent
• Uncertainty about etiology of kidney disease
• Need for potential kidney biopsy to establish diagnosis

The differential diagnosis in a 17-year-old with this presentation includes focal segmental glomerulosclerosis (FSGS), IgA nephropathy, membranous nephropathy, lupus nephritis, or post-infectious glomerulonephritis—not simple hypertensive nephrosclerosis, which would be extremely unusual at this age 4, 5

Immediate Pharmacologic Management

First-Line Antihypertensive Therapy

Start an ACE inhibitor (preferred) or ARB immediately at maximum tolerated doses before the nephrology appointment, as these agents provide both blood pressure control and renal protection beyond their antihypertensive effects 1, 6

• Do NOT delay initiation waiting for the nephrology appointment, as early RAAS blockade is critical for slowing progression 6, 7
• Examples: Lisinopril 10-40 mg daily, enalapril 5-40 mg daily, or losartan 50-100 mg daily 8

Blood Pressure Target

• Target systolic blood pressure <120 mmHg using standardized office measurement in adults, or 24-hour mean arterial pressure at the 50th percentile for age, sex, and height by ambulatory blood pressure monitoring in adolescents 1
• In practical terms for a 17-year-old, aim for BP <120-130/80 mmHg 8

Monitoring After ACE Inhibitor/ARB Initiation

• Recheck serum creatinine and potassium within 7-14 days after starting or uptitrating ACE inhibitor/ARB 6, 2, 5
• Accept and tolerate up to 20-30% increase in serum creatinine, which reflects hemodynamic changes from reduced intraglomerular pressure, not progressive kidney damage 5
• Stop the ACE inhibitor/ARB only if: serum creatinine increases >30%, refractory hyperkalemia develops (>5.5-6.0 mEq/L despite management), or kidney function continues to worsen 1

Adding Additional Antihypertensive Agents

If blood pressure remains ≥140/90 mmHg on ACE inhibitor/ARB alone:

Second-Line Agent

Add a thiazide-like diuretic (chlorthalidone 12.5-25 mg daily or indapamide 1.25-2.5 mg daily preferred over hydrochlorothiazide due to superior cardiovascular outcomes and longer duration of action) 6, 5

Third-Line Agent

If BP remains elevated, add a long-acting dihydropyridine calcium channel blocker (amlodipine 5-10 mg daily or nifedipine extended-release 30-60 mg daily) 6

Important caveat: Dihydropyridine calcium channel blockers may exacerbate edema and can increase proteinuria, so monitor proteinuria closely after initiation 1

Resistant Hypertension (BP ≥140/90 on 3 agents)

Add a mineralocorticoid receptor antagonist (spironolactone 25-50 mg daily or eplerenone 50-100 mg daily), which provides additional antiproteinuric effects 6, 1

• Monitor potassium closely (risk of hyperkalemia when combined with ACE inhibitor/ARB) 1

Proteinuria Management Strategy

Uptitrate ACE Inhibitor/ARB to Maximum Tolerated Dose

• The goal is proteinuria reduction by ≥30-50% from baseline, ideally to <1 g/day, though this varies by underlying disease 1, 5
• Continue uptitration every 2-4 weeks until maximum dose reached or side effects develop 8

Adjunctive Measures for Proteinuria Reduction

• Intensify dietary sodium restriction to <2 g/day (ideally 1,200-2,300 mg/day) to enhance medication effectiveness and independently reduce proteinuria 1, 6, 5
• Consider adding a mineralocorticoid receptor antagonist if proteinuria remains elevated despite maximum ACE inhibitor/ARB dose 1

Essential Lifestyle Modifications

These must be implemented immediately alongside pharmacotherapy: 1, 6

• Sodium restriction: <2 g/day (<90 mmol/day)
• Weight normalization if BMI >25 through caloric restriction
• Regular aerobic exercise: ≥150 minutes/week of moderate-intensity activity
• Smoking cessation if applicable
• Alcohol limitation: ≤1 drink/day for females, ≤2 drinks/day for males

Critical "Sick Day Rules" Counseling

Counsel the patient and family to temporarily hold ACE inhibitor/ARB and diuretics during episodes of: 1

• Vomiting or diarrhea
• Excessive sweating or heat exposure
• Inadequate fluid intake
• Any acute illness causing volume depletion

This prevents hemodynamic acute kidney injury, though this practice has been challenged and remains somewhat controversial 1

Common Pitfalls to Avoid

Do Not Assume Hypertensive Nephrosclerosis

Heavy proteinuria (>3 g/day) in a 17-year-old with hypertension is not typical of hypertensive nephrosclerosis and mandates investigation for primary glomerular disease 4, 9

Do Not Delay ACE Inhibitor/ARB Initiation

Exception: If the patient presents with abrupt onset nephrotic syndrome (suggesting minimal change disease), ACE inhibitors/ARBs can cause acute kidney injury and should be used cautiously or delayed until after initial immunosuppression 1

Do Not Stop ACE Inhibitor/ARB for Modest Creatinine Rise

A stable increase in serum creatinine up to 30% is expected and acceptable; stopping prematurely removes critical renal protection 1

Monitor for Hyperkalemia Aggressively

The combination of ACE inhibitor/ARB with spironolactone or dietary potassium supplementation significantly increases hyperkalemia risk—check potassium within 1-2 weeks of any dose change 1, 6

Follow-Up Monitoring Schedule

• Serum creatinine, eGFR, and potassium: Within 7-14 days after starting/changing ACE inhibitor/ARB, then monthly until stable, then every 3-6 months 6, 2
• Urine protein-to-creatinine ratio: Every 3-6 months to assess treatment response 6, 5
• Blood pressure: At every visit until controlled (<120-130/80 mmHg), then periodically 6, 2