Does a 74-year-old female patient with chronic kidney disease (CKD), type 2 diabetes, iron deficiency anemia, elevated liver enzymes, hypocalcemia, and metabolic acidosis require initiation of sodium bicarbonate and what other treatments are necessary for her condition?

Sodium Bicarbonate Therapy and Additional Management Needs

Yes, this patient should start sodium bicarbonate therapy immediately given her bicarbonate level of 20 mmol/L, which is below the recommended threshold of 22 mmol/L for CKD patients. 1, 2, 3

Bicarbonate Therapy Initiation

Clear Indication Present

• Start oral sodium bicarbonate now because serum bicarbonate is 20 mmol/L (below the 22 mmol/L threshold recommended by KDIGO and National Kidney Foundation guidelines) 1, 2, 3
• The target is to maintain serum bicarbonate ≥22 mmol/L but not exceeding the upper limit of normal (typically 28-29 mmol/L) 1, 2

Dosing Recommendations

• Start with 650 mg (approximately 8 mEq) orally 2-3 times daily as the nurse note suggests, which is appropriate 1
• The typical effective dose range is 2-4 g/day (25-50 mEq/day), so starting with 1.3-2.0 g/day (650 mg × 2-3 times daily) is reasonable and can be titrated up 1, 2
• Monitor serum bicarbonate monthly initially, then every 3 months once stable 1, 3

Critical Monitoring for This Patient

• Blood pressure monitoring is essential given her already elevated BP (180/60 mmHg initially, improved to 166/68 mmHg) because sodium bicarbonate adds sodium load 1, 2
• However, concurrent severe dietary sodium chloride restriction (<2 g sodium/day) can prevent blood pressure increases 2
• Monitor for volume overload and edema (she already has mild bilateral lower extremity edema) 1, 2
• Check serum potassium, especially since she may need RAS inhibitor therapy for proteinuria 4, 1

Clinical Benefits Expected

• Slows CKD progression (creatinine doubling occurred in only 6.6% of bicarbonate-treated patients versus 17.0% in standard care) 5
• Prevents protein degradation and improves albumin synthesis (important given her hypoalbuminemia of 2.9 g/dL) 1, 2, 6
• Reduces bone resorption (relevant given her elevated alkaline phosphatase of 246) 1, 3, 6
• May help manage hyperkalemia if RAS inhibitors are initiated 4, 1

Critical Missing Therapies

1. RAS Inhibitor Therapy - URGENT PRIORITY

• This patient needs an ACE inhibitor or ARB immediately given her 2+ proteinuria and CKD 4
• KDIGO 2024 guidelines strongly recommend RAS inhibitors for patients with CKD and albuminuria >30 mg/g 4
• The diltiazem ER 120 mg started for blood pressure is not adequate as it does not provide kidney protection like RAS inhibitors do 4
• Start with a low dose (e.g., lisinopril 5-10 mg daily or losartan 25-50 mg daily) and titrate to maximum tolerated dose 4
• Check creatinine and potassium within 2-4 weeks of initiation; continue therapy unless creatinine rises >30% 4

2. SGLT2 Inhibitor Therapy - HIGH PRIORITY

• Strongly consider adding an SGLT2 inhibitor (empagliflozin, dapagliflozin, or canagliflozin) 4
• KDIGO 2024 gives a 1A recommendation for SGLT2i in adults with CKD and eGFR ≥20 mL/min/1.73 m² with urine ACR ≥200 mg/g 4
• Her proteinuria (2+) likely exceeds this threshold 4
• Benefits include slowing CKD progression and cardiovascular protection 4
• Can be used in combination with RAS inhibitors 4
• Her A1c of 6.8% indicates diabetes, making this even more appropriate 4

3. Nonsteroidal Mineralocorticoid Receptor Antagonist - CONSIDER

• Consider finerenone if albuminuria persists despite maximum tolerated RAS inhibitor and SGLT2i therapy 4
• KDIGO 2024 suggests nonsteroidal MRA for adults with T2D, eGFR >25 mL/min/1.73 m², normal potassium, and persistent albuminuria despite standard therapy 4
• Note: Spironolactone was discontinued during hospitalization, likely due to hyperkalemia risk with worsening renal function 4

4. Statin Therapy Clarification

• The nurse note mentions "continue current statin therapy" but no statin is listed in her current medications 4
• Verify if she is actually taking a statin; if not, initiate moderate-intensity statin therapy for cardiovascular risk reduction in CKD 4

5. Iron Deficiency Management - ALREADY ADDRESSED

• IV iron therapy referral is appropriate given her severe iron deficiency (iron 26, saturation 8%, ferritin 51) and recent GI bleeding 1
• Oral iron is correctly avoided due to poor absorption in CKD and recent GI bleeding 1

6. Fluid Restriction Reassessment

• The 1.5-liter daily fluid restriction should be discontinued given her prerenal AKI pattern and volume depletion 1
• The nurse note correctly states bumetanide and fluid restriction were discontinued 1
• However, the patient reports "continued adherence to a 1.5-liter daily fluid restriction" - she needs clear instruction to stop this restriction 1

Critical Pitfalls to Avoid

Blood Pressure Management

• Do not rely solely on diltiazem for blood pressure control - RAS inhibitors are mandatory for kidney protection in proteinuric CKD 4
• The propranolol being held due to heart rate <60 bpm is appropriate, but blood pressure remains poorly controlled 4

Sodium Bicarbonate Cautions

• Exercise caution with sodium load given her history of volume overload requiring large-volume paracentesis (13 liters total) 1, 2
• However, she currently has prerenal AKI from volume depletion, so sodium bicarbonate is appropriate now 1
• Implement strict dietary sodium chloride restriction (<2 g/day) to prevent blood pressure increases 2

Hyperkalemia Risk

• Monitor potassium closely when initiating RAS inhibitors and sodium bicarbonate together 4
• Sodium bicarbonate can help manage hyperkalemia, allowing continuation of RAS inhibitors 4, 1
• Do not discontinue RAS inhibitors for mild hyperkalemia; use potassium binders, dietary restriction, and bicarbonate therapy instead 4

GI Bleeding Follow-up

• Ensure gastroenterology referral is completed given her recent bloody diarrhea and elevated liver enzymes 1
• The referral was "already placed" but needs confirmation of appointment 1

Monitoring Algorithm

Within 2 Weeks

• Repeat CMP to assess response to bicarbonate therapy and check creatinine/potassium after RAS inhibitor initiation 4, 1
• Blood pressure monitoring 4, 2

Monthly

• Serum bicarbonate until stable at ≥22 mmol/L 1, 3
• Blood pressure and weight monitoring 2

Every 3 Months

• CBC and iron studies (after IV iron therapy) 1
• Serum bicarbonate once stable 1, 3
• Hemoglobin A1c 4
• CMP with electrolytes 4