Managing CKD in the Setting of Glomerulonephritis

1. Establish the Diagnosis First

2. Disease-Specific (Immunosuppressive) Therapy

Key point from textbooks: Rapidly progressive GN (RPGN) with crescents on biopsy requires urgent, intensive immunosuppressive therapy - delays worsen outcomes significantly. - Campbell Walsh Wein Urology

3. Slowing CKD Progression - The RAAS Backbone

• Reduce glomerular capillary pressure (lower P-GC) and thus proteinuria
• Block angiotensin II-mediated TGF-β1 upregulation and fibrosis
• In experimental models of nephrotoxic serum nephritis, ACE inhibition lowered intraglomerular pressure, prevented proteinuria, and ameliorated glomerulosclerosis
• Target BP: < 130/80 mmHg in CKD with proteinuria

4. Managing CKD Complications (by Stage)

Hypertension

• Target < 130/80 mmHg (especially with proteinuria)
• Preferred: ACE-i/ARB (also reduces proteinuria)
• Add loop diuretics, CCBs, or mineralocorticoid receptor antagonists (e.g., finerenone) as needed
• Avoid NSAIDs - worsen GFR and increase proteinuria

Proteinuria Monitoring

• Urine albumin-to-creatinine ratio (ACR) or protein-to-creatinine ratio at each visit
• Target reduction in proteinuria is itself a surrogate for preserved renal function

Anemia (develops in CKD G3a-G5)

• Diagnose: Hb < 13 g/dL (males), < 12 g/dL (females)
• Work up: iron stores, B12, folate FIRST
• Treat iron deficiency (oral or IV iron)
• Erythropoiesis-stimulating agents (ESAs, e.g., darbepoetin): start when Hb < 10 g/dL after correcting iron deficiency
• Caution: ESAs carry risk of stroke and possibly malignancy at high Hb targets - Comprehensive Clinical Nephrology, 7th Edition

Bone and Mineral Disorder (CKD-MBD)

• Monitor calcium, phosphate, PTH, and alkaline phosphatase when GFR < 45 mL/min (G3b-G5)
• Restrict dietary phosphate; use phosphate binders (calcium carbonate, sevelamer) if hyperphosphatemic
• Vitamin D analogs (calcitriol/alfacalcidol) for secondary hyperparathyroidism
• Cinacalcet (oral calcimimetic) for dialysis patients with refractory secondary hyperparathyroidism
• Avoid routine vitamin D supplementation without documented deficiency

Metabolic Acidosis

• Diagnose: serum bicarbonate < 22 mmol/L
• Treat with oral sodium bicarbonate supplementation
• Correcting acidosis may slow kidney disease progression
• Caution: sodium load may worsen hypertension and fluid retention in patients with heavy proteinuria

Hyperkalemia

• Exacerbated by RAAS blockade and acidosis
• Dietary potassium restriction
• Consider potassium binders (patiromer, sodium zirconium cyclosilicate) to allow continued RAAS blockade
• Severe hyperkalemia (> 6.5 mEq/L with ECG changes) requires urgent management or initiation of dialysis

Cardiovascular Risk Reduction

• Statins: offer to all CKD patients > 50 years (KDIGO recommends regardless of baseline lipid levels)
• Antiplatelet therapy for secondary CVD prevention (caution: increased bleeding risk)
• Screen for left ventricular hypertrophy; optimize BP

Infections and Vaccinations

• Annual influenza vaccine for all CKD patients
• Pneumococcal vaccine for eGFR < 30 mL/min or nephrotic syndrome/immunosuppression (revaccinate at 5 years)
• Hepatitis B vaccine series for eGFR < 30 mL/min (check anti-HBs titer post-vaccination)
• Avoid live vaccines in immunosuppressed patients

5. Diet and Lifestyle

• Protein restriction: 0.6-0.8 g/kg/day in non-dialysis CKD (reduces proteinuria and uremic burden); avoid high protein in nephrotic states
• Salt restriction: < 2 g sodium/day (helps BP and edema control)
• Smoking cessation: accelerates kidney disease progression and cardiovascular risk
• Fluid restriction: only in oliguria or severe edema
• Referral to renal dietitian strongly recommended for G3b and beyond

6. Preparation for Renal Replacement Therapy (RRT)

• Begin counseling for RRT options when eGFR falls to 15-20 mL/min
• Start hemodialysis/peritoneal dialysis before symptomatic uremia (typically eGFR 5-10 mL/min) - do NOT initiate based solely on GFR without symptoms
• Create AV fistula or peritoneal catheter ideally 3-6 months before anticipated need
• Consider preemptive kidney transplant listing in eligible patients (best long-term outcome)

7. Monitoring Schedule (KDIGO)

Recent Evidence Note

Warfarin with INR 4.5 and aPTT 96 - Inpatient Management

First: Interpret the Labs

• INR 4.5 = supratherapeutic warfarin effect (target is usually 2-3 or 2.5-3.5 depending on indication)
• aPTT 96 = elevated (normal ~25-35 sec); warfarin primarily prolongs PT/INR, but can modestly prolong aPTT too
• An aPTT of 96 sec is notably high for warfarin alone - this should raise a red flag

Stop and assess: Is this patient also on heparin, LMWH, or a direct thrombin inhibitor? Warfarin alone rarely elevates aPTT this dramatically. Rule out combined anticoagulation, lupus anticoagulant, or a clotting factor deficiency before attributing the aPTT purely to warfarin.

Step-by-Step Management

Step 1 - Is the Patient Actively Bleeding?

A. NO Active Bleeding (INR 4.5, Asymptomatic)

• Hold warfarin (omit 1-2 doses)
• Recheck INR every 24 hours until it falls below 4
• For patients with high bleeding risk (elderly, prior GI bleed, recent surgery, renal failure as in this CKD patient): give oral Vitamin K 1-2.5 mg PO x 1
• When INR approaches therapeutic range, restart warfarin at a lower dose - The Harriet Lane Handbook, 23rd Ed

B. Active Bleeding Present

Key point: 4-factor prothrombin complex concentrate (PCC) is preferred over FFP for major warfarin-related bleeding because it acts faster, requires smaller volume, and gives more reliable INR correction. - Washington Manual of Medical Therapeutics; Campbell's Operative Orthopaedics 15th Ed

Step 2 - Investigate Why INR is Supratherapeutic

• Antibiotics: metronidazole, ciprofloxacin, clarithromycin, TMP-SMX (Bactrim)
• Antifungals: fluconazole, itraconazole, miconazole
• Amiodarone (very potent - can double INR)
• Omeprazole, isoniazid, disulfiram

• Reduced oral intake / dietary vitamin K deficiency
• Intercurrent illness (diarrhea, fever, hepatic congestion)
• Accidental overdose or change in warfarin brand
• Renal impairment (this patient has CKD - reduced warfarin clearance)
• Alcohol excess

Step 3 - Additional Inpatient Orders

1. Hold warfarin - do not give next dose
2. Vitamin K - dose as per bleeding status (see above)
3. Serial INR monitoring - Q24h if no bleed, Q12h if INR >10, Q4-6h if actively bleeding
4. Check aPTT repeat + consider mixing study to rule out inhibitor or heparin contamination if aPTT remains disproportionately elevated
5. Renal function panel (CKD patient - check for acute-on-chronic deterioration)
6. CBC - check Hb, platelets
7. Review drug chart - identify any interacting medications and stop/adjust them
8. Clinical examination - check for signs of occult bleeding (neuro exam, abdominal tenderness, urine color, stool for occult blood)
9. Inform patient - counsel about bleeding precautions, soft toothbrush, avoid NSAIDs/aspirin

Step 4 - Restarting Warfarin

• Do NOT restart until INR is back in the therapeutic range (usually 2-3)
• Restart at a lower dose (typically 10-20% reduction)
• Identify and address the precipitating cause before restarting
• More frequent INR monitoring in the first 1-2 weeks after restart
• In CKD patients, warfarin doses tend to run lower due to altered pharmacokinetics - review whether current dose was appropriate to begin with

Important Note on This Patient

• CKD causes platelet dysfunction and uremic coagulopathy (independently increases bleeding tendency)
• CKD reduces vitamin K-dependent clotting factor synthesis in advanced stages
• CKD reduces warfarin clearance, causing dose accumulation

DVT + CKD on Warfarin - INR 4.5, aPTT 96: Step-by-Step Management

Immediate First Question: Is the Patient Bleeding?

Understanding the Labs

Critical flag: Warfarin alone mainly prolongs PT/INR (inhibits factors II, VII, IX, X). An aPTT of 96 sec is far above what warfarin alone typically causes. Before doing anything else, ask:

• Is the patient also receiving heparin or LMWH (bridging therapy)?
• Is there a lupus anticoagulant present?
• Could there be DIC or severe liver disease?
• Is there a specific factor deficiency?

If no heparin is running, send a mixing study (1:1 mix of patient plasma + normal plasma) to distinguish factor deficiency from an inhibitor.

Management Algorithm by Bleeding Status

SCENARIO A: INR 4.5 with NO Active Bleeding

• Hold warfarin (stop next dose, do not give)
• Recheck INR every 24 hours until it falls below 3
• For patients with higher bleeding risk or lower thromboembolic risk: give Vitamin K 2.5 mg orally x 1
• This patient has CKD - that increases bleeding risk, so oral vitamin K is appropriate

SCENARIO B: Minor Bleeding (e.g., minor hematuria, small hematoma, epistaxis)

• Hold warfarin
• Vitamin K 1-2.5 mg PO or 0.5-2.5 mg IV x 1
• Recheck INR Q12-24 hours
• Repeat vitamin K dose in 24h if INR not corrected and bleeding persists
• Supportive local measures for bleeding site

SCENARIO C: Significant Active Bleeding (GI bleed, significant hematuria, hemoptysis)

• Stop warfarin immediately
• Vitamin K 5-10 mg IV - give as slow infusion over 20-30 minutes (never rapid IV bolus - risk of anaphylaxis)
• 4-factor PCC (Kcentra) - preferred over FFP - dose for INR 4-6: 35 units/kg IV, max 3500 units
• If PCC unavailable: FFP 10-15 mL/kg
• Recheck INR Q4-6 hours
• Repeat vitamin K if INR not corrected at 12-24h

SCENARIO D: Life-Threatening / Major Bleeding (intracranial bleed, massive GI bleed, hemodynamic instability)

• Stop warfarin immediately
• Vitamin K 10 mg IV over 30 minutes (can repeat Q12h based on repeat INR)
• 4F-PCC (Kcentra) 35 units/kg IV (max 3500 units for INR 4-6) - this is the first-line reversal agent
• If PCC unavailable: FFP 10-30 mL/kg
• Recheck INR Q4-6 hours
• Supportive resuscitation: IV access, fluids, type and crossmatch, blood transfusion if Hb <7-8 g/dL
• Involve hematology ± relevant specialty (gastroenterology, neurosurgery) urgently

Why PCC over FFP? PCC contains concentrated factors II, VII, IX, X + protein C and S, works within minutes, requires a small volume (critical in CKD patients who cannot tolerate volume load). - Rosen's Emergency Medicine

Specific Considerations for This Patient: DVT + CKD

1. CKD Increases Bleeding Risk

• Uremic platelet dysfunction compounds the coagulopathy
• Warfarin is more unpredictable in CKD due to reduced clearance and altered protein binding
• Be more aggressive with vitamin K even at "borderline" supratherapeutic INR

2. DVT Clot Risk Still Present

• Holding warfarin temporarily is safe for short periods (days) in a treated DVT, as the clot is already stable
• Do NOT reverse anticoagulation unless clinically necessary - the DVT remains a thrombotic risk
• Weigh: bleeding risk vs. re-thrombosis risk when deciding vitamin K dose and how quickly to restart

3. Consider Switching Anticoagulant After Stabilization

• Warfarin in CKD is difficult to manage (variable INR, frequent monitoring required)
• However, note that in severe renal failure (eGFR <15-30 mL/min), DOACs are either contraindicated or not well-studied for DVT treatment - warfarin may remain the best option in advanced CKD
• If CKD is moderate (G3-G4), apixaban is the DOAC with the best evidence in renal impairment for VTE treatment - discuss with hematology/nephrology

4. Investigate the Cause of Supratherapeutic INR

Complete Inpatient Orders Summary

1. Hold warfarin - do not give tonight's dose
2. Vitamin K - dose per bleeding scenario above
3. Repeat INR + aPTT - in 12-24h (or Q4-6h if bleeding)
4. Mixing study for aPTT 96 - to rule out inhibitor vs. factor deficiency vs. heparin effect
5. CBC - check Hb, platelet count
6. Renal function - check eGFR, electrolytes (hyperkalemia risk in CKD)
7. Stool occult blood test + urine dipstick for occult bleeding
8. Neurological exam - rule out any subtle intracranial bleed
9. Review drug chart - identify any interacting medications
10. Bleeding precautions - soft diet, avoid NSAIDs/aspirin/antiplatelet agents, fall precautions
11. Discuss anticoagulation plan with patient: lower warfarin dose on restart, more frequent INR checks

DVT on Warfarin x 15 Days - INR 4.5, aPTT 96: What to Do Next

The Clinical Picture at 15 Days

• The clot is not yet fully organized/stabilized
• You cannot stop anticoagulation entirely without significant re-thrombosis/PE risk
• Your job is to bring the INR down safely and restart at the correct dose - NOT permanently stop therapy

Step 1 - Red Flag First: Why is aPTT 96?

• Is the patient also on heparin or LMWH (bridging therapy started with warfarin)? This is very common in the first 5-10 days of DVT treatment and would fully explain aPTT 96.
• If yes - stop heparin/LMWH now, that is the primary problem
• If no heparin running - send mixing study to rule out a factor inhibitor or lupus anticoagulant
• Also consider: severe liver disease, DIC, or accidental ingestion of another anticoagulant

Step 2 - Is the Patient Bleeding?

A. NO Active Bleeding (most likely scenario at INR 4.5)

1. Hold warfarin today (skip tonight's dose)
2. Give Vitamin K 1-2.5 mg orally - reasonable at INR 4.5, brings INR down faster, reduces bleeding risk during this vulnerable early-DVT period
3. Recheck INR in 24 hours - continue holding until INR is 2.0-3.0
4. Stop heparin/LMWH if running (that is likely what is driving the aPTT to 96)
5. Restart warfarin at a lower dose once INR is in range

Oral vitamin K is preferred over IV unless bleeding is present. Subcutaneous is the worst route due to erratic absorption. If IV is needed, give slowly over 20-30 minutes - never as a rapid bolus (risk of anaphylaxis). - Rosen's Emergency Medicine

B. Minor Bleeding (small hematoma, mild epistaxis, minor hematuria)

• Hold warfarin
• Vitamin K 1-2.5 mg PO or 0.5-2.5 mg IV
• Stop heparin/LMWH if running
• Recheck INR Q12-24h
• Local hemostatic measures

C. Significant or Life-Threatening Bleeding (major GI bleed, intracranial, hemodynamic compromise)

• Stop warfarin AND heparin immediately
• Vitamin K 10 mg IV over 30 min (repeat Q12h based on INR)
• 4-factor PCC (Kcentra) 35 units/kg IV (max 3500 units) for INR 4-6 - this is preferred over FFP
• If PCC unavailable: FFP 10-15 mL/kg
• Recheck INR Q4-6h
• Involve hematology + relevant specialty urgently
• Resuscitate, type and crossmatch

Step 3 - Find Out WHY the INR Overshot at 15 Days

Step 4 - Restarting Warfarin After INR Normalizes

• Restart once INR is 2.0-3.0
• Use a dose 10-20% lower than current dose
• Check INR again in 5-7 days after restarting
• Consider more frequent monitoring (weekly) for the first month

Step 5 - Consider Switching to a DOAC

• DOACs (apixaban, rivaroxaban) are associated with lower recurrent VTE risk AND lower bleeding rates compared to warfarin
• They do not require INR monitoring
• Rivaroxaban or apixaban are the most commonly used for DVT; apixaban has the best safety profile
• Warfarin remains necessary in: severe renal failure (eGFR <15-30), antiphospholipid syndrome, pregnancy, severe liver disease
• If none of those apply, seriously consider switching once the patient is stable - Rosen's Emergency Medicine

Summary Action Card

INR 4.5, aPTT 96, DVT Day 15 - No active bleeding

1. CHECK medication chart - is heparin/LMWH still running? Stop it.
2. HOLD warfarin (today's dose)
3. GIVE Vitamin K 2.5 mg PO x 1
4. RECHECK INR in 24h; aPTT after stopping heparin
5. INVESTIGATE: drug interactions, dietary change, dose error
6. RESTART warfarin at lower dose when INR 2-3
7. CONSIDER switching to apixaban/rivaroxaban
8. Continue anticoagulation for minimum 3 months total

DVT on Warfarin Day 15 - INR 4.5, aPTT 96

First and Most Important Question

Step-by-Step Management

Branch on Bleeding Status

NO Active Bleeding (INR 4.5)

1. Hold warfarin - skip today's dose
2. Stop heparin/LMWH if still running
3. Vitamin K 2.5 mg orally x 1 - reasonable at INR 4.5 to bring it down faster, especially given active DVT where bleeding risk must be balanced against ongoing clot risk
4. Recheck INR in 24 hours - keep holding warfarin until INR is 2.0-3.0
5. Recheck aPTT after stopping heparin - if it normalizes, heparin was the cause; if still high, investigate further

Minor Bleeding (small hematoma, nosebleed, minor hematuria)

1. Hold warfarin + stop heparin/LMWH
2. Vitamin K 1-2.5 mg PO or 0.5-2.5 mg IV slow infusion
3. Recheck INR Q12-24h
4. Local hemostatic measures

Significant or Life-Threatening Bleeding (major GI bleed, intracranial, hemodynamic shock)

1. Stop warfarin AND heparin immediately
2. Vitamin K 10 mg IV over 30 minutes (never rapid bolus - anaphylaxis risk)
3. 4-factor PCC (Kcentra) 35 units/kg IV, max 3500 units - preferred over FFP for INR 4-6
4. If PCC unavailable: FFP 10-15 mL/kg
5. Recheck INR Q4-6h; repeat vitamin K if not corrected
6. Urgent hematology + relevant specialty consult

Why Did INR Overshoot at Day 15? (Investigate)

Restarting Anticoagulation

• Restart warfarin at 10-20% lower dose once INR is 2.0-3.0
• Recheck INR in 5-7 days after restart
• Target INR: 2.0-3.0 for DVT

Quick Summary Card

DVT Day 15 | INR 4.5 | aPTT 96

→ Is heparin/LMWH still running? YES → STOP it immediately
→ Active bleeding? NO → Hold warfarin + Vit K 2.5mg PO
→ Active bleeding? YES → Hold all anticoagulants
                         Vit K 10mg IV over 30 min
                         4F-PCC 35 units/kg IV
→ Recheck INR in 24h
→ Restart warfarin (lower dose) when INR 2-3
→ Must complete minimum 3 months total