Renal & Urinary

CKD: dialysis preparation and vascular access

Clinical Overview and When to Suspect Need for Dialysis Preparation

— eGFR <30 (CKD stage 4): refer to nephrology if not already followed; begin patient education on modality options (hemodialysis [HD], peritoneal dialysis [PD], preemptive transplant, conservative care)

— eGFR <20: place on kidney transplant waiting list (UNOS allows listing at eGFR ≤20); accrual of waitlist time begins

— eGFR <15–20 with progressive decline: create vascular access for anticipated HD — typically when initiation is expected within 6–12 months

— Acidosis refractory to bicarbonate

— Electrolytes (hyperkalemia refractory to medical therapy)

— Ingestion (dialyzable toxin)

— Overload (volume) refractory to diuretics

— Uremia: pericarditis, encephalopathy, bleeding, intractable nausea

Chronic kidney disease (CKD) is defined by GFR <60 mL/min/1.73 m² or markers of kidney damage (albuminuria, structural disease) persisting ≥3 months. Dialysis preparation is a longitudinal outpatient process, not a last-minute inpatient scramble.

When to begin preparation — the "1875 rule" for Step 3:

Indications to actually start dialysis (AEIOU mnemonic, but Step 3 emphasizes symptoms over numbers):

The IDEAL trial showed no benefit to early (eGFR 10–14) vs. late (5–7) initiation — start based on symptoms, not arbitrary GFR.

Step 3 management: A 62-year-old with diabetic nephropathy, eGFR 24, asymptomatic — the next best step is nephrology referral, modality education, vaccination updates (hep B, pneumococcal, influenza), and AV fistula planning in the non-dominant arm. Do NOT place a PICC, midline, or subclavian line — these destroy future access sites.

Board pearl: The single most modifiable predictor of dialysis survival is avoiding a central venous catheter at initiation. Every CKD stage 4 patient gets a "save the veins" wristband mentality — no IVs in the forearm of the non-dominant arm.

Presentation Patterns and Key History

— eGFR 30–45: usually asymptomatic; anemia, secondary hyperparathyroidism begin

— eGFR 15–30: fatigue, nocturia, mild anorexia, restless legs, pruritus, declining exercise tolerance

— eGFR <15: nausea, vomiting, metallic taste, hiccups, encephalopathy, asterixis, pericardial rub, uremic frost (rare)

— Rate of decline: plot eGFR slope; >5 mL/min/yr loss is rapid progression

— Cause of CKD: diabetes (#1 US), hypertension, glomerular disease, polycystic — affects transplant candidacy and recurrence risk

— Comorbidities affecting access: prior central lines, pacemakers (ipsilateral central stenosis), PAD, heart failure (high-output failure risk with fistula), severe LV dysfunction (EF <30% is relative contraindication to large AVF)

— Hand dominance — fistula goes in non-dominant arm

— Functional status, social support, home environment — drives HD vs. PD vs. conservative decision

The "crashing into dialysis" patient — late nephrology referral, presenting to ED with uremic symptoms and needing emergent tunneled catheter. This is the Step 3 anti-pattern the exam wants you to prevent.

Symptom timeline as eGFR declines:

Key historical elements to elicit at every CKD visit:

Modality counseling history: ask about employment, ability to self-cannulate (home HD), willingness/space for PD supplies, caregiver availability.

Advance care planning: in patients >75 with multimorbidity, conservative (non-dialytic) management has comparable survival and better quality of life — must be offered.

CCS pearl: On a CCS case of advanced CKD, your standing orders should include: nephrology consult, dietitian (renal diet), social work (modality + transplant eval), vascular surgery referral for access, and vein preservation orders ("no BPs, no IVs, no venipuncture in left arm").

Board pearl: A patient referred to nephrology <90 days before dialysis initiation has roughly 2× mortality vs. early-referred patients — late referral is itself the wrong answer.

Physical Exam Findings and Vascular Access Assessment

— Allen test before radiocephalic fistula — confirms ulnar collateral perfusion

— Arterial inflow: bilateral brachial BP (>20 mmHg difference suggests subclavian stenosis), radial/ulnar/brachial pulses

— Venous outflow: examine cephalic and basilic veins with tourniquet applied — palpate compressibility, continuity, prior IV/phlebotomy scars

— Central vein patency: look for collateral chest wall veins, arm edema, facial swelling suggesting prior central stenosis (from old catheters, pacemakers)

— Look: aneurysms, skin breakdown, prolonged bleeding after cannulation, "steal" signs (pale, cold, painful hand)

— Listen: continuous low-pitched bruit (normal) vs. high-pitched discontinuous (stenosis)

— Feel: soft, easily compressible thrill (normal) vs. water-hammer/hyperpulsatile (outflow stenosis) vs. absent (thrombosis)

General CKD exam: pallor (anemia), volume status (JVP, edema, lung crackles, S3), uremic signs (asterixis, pericardial friction rub, ecchymoses from platelet dysfunction), excoriations from pruritus, Kussmaul respirations if acidotic.

Pre-access vascular exam — the cornerstone of Step 3 dialysis prep:

Vein-mapping ultrasound is the next step before surgical referral — vein ≥2.5 mm diameter and artery ≥2.0 mm predict fistula maturation.

Examining an existing AV access — the "Look, Listen, Feel" maneuver every visit:

Arm elevation test: a mature fistula partially collapses with elevation; a fistula with outflow stenosis remains distended.

Key distinction: Pulsatile access = outflow obstruction (stenosis/thrombosis impending). Thrill = normal flow. This single finding on rounds drives urgent fistulogram referral.

Board pearl: New hand pain, pallor, or weakness in the access arm = dialysis access-induced steal syndrome (DASS) — urgent vascular surgery referral; untreated → ischemic monomelic neuropathy and permanent hand dysfunction.

Diagnostic Workup — Labs Driving Dialysis Preparation

— BMP: track eGFR trend, K⁺, HCO₃⁻ (treat <22 with oral bicarbonate)

— CBC: Hgb target 10–11 g/dL on ESA therapy (not normalization — TREAT, CHOIR, CREATE trials showed harm from Hgb >13)

— Iron studies: TSAT >30%, ferritin >500 before/with ESA

— Ca, Phos, PTH, 25-OH vitamin D — CKD-MBD management

— Albumin — nutritional marker, predicts dialysis mortality

— Lipid panel — statin indicated in CKD (SHARP trial); do NOT initiate statin in patients already on dialysis if not previously on one (4D, AURORA trials)

— Hepatitis B surface Ag, anti-HBs, anti-HBc; Hep C Ab; HIV — required before transplant listing and to guide isolation in HD units

— Hep B vaccine series with double-dose (40 mcg) in CKD — check anti-HBs titer, booster if <10

— Pneumococcal (PCV15→PPSV23 or PCV20), influenza annually, COVID, Tdap, zoster, RSV per age

Baseline and serial labs in advanced CKD (every 1–3 months at stage 4–5):

Urine studies: UACR (albumin:creatinine ratio) — guides RAAS therapy, SGLT2 inhibitor candidacy; UA for active sediment if etiology unclear.

Pre-transplant/pre-access serologies:

PPD or IGRA before transplant evaluation.

EKG and echocardiogram: baseline in all advanced CKD; LVH and reduced EF affect access choice (high-output HF risk with proximal AVF).

Step 3 management: A stage 4 CKD patient with Hgb 9.2, TSAT 18%, ferritin 80 — next step is IV iron, not ESA. Always replete iron first; ESAs without iron worsen functional iron deficiency and are ineffective.

Board pearl: A patient about to start HD needs hepatitis B vaccination completed before initiation — HD units segregate HBsAg+ patients, and seroconversion rates drop dramatically once dialysis begins. Vaccinate early in stage 4.

Diagnostic Workup — Vein Mapping and Cardiac Optimization

— Arterial criteria: lumen ≥2.0 mm, no significant calcification, biphasic/triphasic flow, brachial-radial pressure gradient <20 mmHg

— Venous criteria: lumen ≥2.5 mm with tourniquet, continuous to central system, compressible, no thrombus or stenosis

— Document distance from skin (deep veins >6 mm may need superficialization/transposition)

— Echocardiogram to assess LVEF, valvular disease, pulmonary pressures

— EF <30% is a relative contraindication to high-flow upper-arm fistula (risk of high-output heart failure)

— Consider distal radiocephalic (lower flow) or PD in these patients

Preoperative vein mapping (duplex ultrasound) is mandatory before AV access creation:

Central venogram or MR venography: indicated if prior ipsilateral central catheter, pacemaker, port, or arm/face swelling — central venous stenosis is a contraindication to ipsilateral access creation.

Cardiac evaluation before access:

Coronary evaluation for transplant candidates — stress imaging or coronary angiography per AHA/AST guidelines in high-risk patients (diabetes, prior CAD, age >50).

Bleeding/coagulation workup if history suggests — uremic platelet dysfunction is universal; desmopressin (DDAVP) 0.3 mcg/kg can be given preoperatively for active bleeding or invasive procedures.

Key distinction: Vein mapping ≠ venography. Mapping = peripheral duplex US for AVF planning. Venography = central imaging when stenosis suspected. Step 3 stems will distinguish these.

CCS pearl: Ordering "vascular surgery consult" alone is incomplete on a CKD case — the higher-yield order set is: vein mapping duplex bilateral upper extremities, echocardiogram, hepatitis serologies, transplant referral, and dietitian consult, all simultaneously to compress the timeline.

Board pearl: A patient with a left chest pacemaker and need for AV access: place the fistula in the right (contralateral) arm, because pacemaker leads cause subclavian/innominate stenosis on the ipsilateral side.

Modality Selection and Access Hierarchy Logic

— In-center hemodialysis (HD) — 3×/week, 3–4 hr sessions; most common US modality

— Home hemodialysis — more frequent (5–6×/week, shorter sessions); better BP/LVH outcomes; needs partner

— Peritoneal dialysis (PD) — CAPD (manual exchanges) or APD (cycler at night); preserves residual kidney function; preferred for hemodynamic instability, poor vascular access, young/employed patients

— Preemptive transplant — best survival; pursue aggressively at eGFR <20

— Conservative (non-dialytic) management — elderly, multimorbid, limited life expectancy

— 1st choice: Radiocephalic AVF (Brescia-Cimino, wrist) — lowest complications, longest patency, but highest non-maturation rate

— 2nd: Brachiocephalic AVF (elbow)

— 3rd: Brachiobasilic AVF with transposition (basilic vein moved superficially)

— 4th: AV graft (AVG) — synthetic PTFE; ready in 2–4 weeks vs. 8–12 weeks for fistula; shorter patency, more infections

— Last: Tunneled cuffed central venous catheter — highest infection and mortality risk; only for bridging or no other options

Step 3 wants you to know the modality decision tree cold. Options:

Vascular access hierarchy ("Fistula First, Catheter Last"):

Timing: create AVF 6 months before anticipated HD start (allows for maturation + possible revision). AVG can be placed 2–4 weeks before.

Step 3 management: A 45-year-old diabetic with eGFR 18, declining 4 mL/min/year — place radiocephalic AVF now in non-dominant arm, don't wait for symptoms.

Board pearl: PD is the modality of choice for patients with severe heart failure, poor vascular access options, or who value autonomy/travel flexibility. Absolute contraindications: prior extensive abdominal surgery with adhesions, large ventral hernia, active intra-abdominal infection.

Key distinction: AVF maturation = 8–12 weeks (often longer in diabetics, women, obese). AVG usable = 2–4 weeks. Catheter = same day but bad long-term.

Pharmacotherapy — Optimizing the CKD Patient Pre-Dialysis

— Continue for albuminuria and proteinuric CKD even at low eGFR; STOP-ACEi trial showed no benefit to discontinuation at advanced CKD

— Hold if K⁺ >5.5 refractory, AKI, or symptomatic hypotension

— Do NOT combine ACEi + ARB (ONTARGET — increased AKI)

— Indicated in CKD with eGFR ≥20 regardless of diabetes status (DAPA-CKD, EMPA-KIDNEY); slows progression, reduces CV events

— Continue once started even if eGFR drops below 20 until dialysis

— IV iron first (TSAT <30%, ferritin <500)

— ESA (epoetin, darbepoetin) to target Hgb 10–11 g/dL — avoid >11.5 (stroke, thrombosis, access loss)

— HIF-PHIs (daprodustat) — oral alternative

— Phosphate binders (non-calcium preferred: sevelamer, lanthanum, ferric citrate) when phos >5.5

— Calcitriol or paricalcitol for elevated PTH

— Cinacalcet for secondary hyperparathyroidism on dialysis

RAAS blockade (ACEi or ARB):

SGLT2 inhibitors (dapagliflozin, empagliflozin):

Finerenone: nonsteroidal MRA for diabetic CKD with albuminuria (FIDELIO-DKD); monitor K⁺.

Anemia:

CKD-MBD:

Acidosis: sodium bicarbonate to keep HCO₃⁻ ≥22 — slows CKD progression.

Hyperkalemia chronic management: patiromer or sodium zirconium cyclosilicate to enable continued RAAS therapy.

Statin: moderate-intensity in all CKD not on dialysis (SHARP). Do not initiate in incident dialysis patients.

Avoid/dose-adjust: NSAIDs (never), gabapentin (reduce dose, accumulates), metformin (stop at eGFR <30), gadolinium (NSF risk at eGFR <30), bowel preps with phosphate.

Board pearl: A stage 4 CKD patient on lisinopril, K⁺ 5.6 — the answer is usually add patiromer/SZC and continue ACEi, not stop the ACEi, because RAAS blockade is renoprotective.

Step 3 management: Vaccinate (hep B double-dose, PCV20, flu, COVID, zoster) before dialysis initiation — immune response drops markedly on dialysis.

Vascular Access Procedures and Catheter Management

— Daily "look, listen, feel" by patient; thrill should be palpable immediately

— Fistula exercises (squeeze ball) to promote maturation

— Avoid BPs, IVs, venipuncture, tight clothing, jewelry, sleeping on access arm

— Follow-up at 2 and 6 weeks; duplex US at 4–6 weeks to assess maturation

— Preferred site: right internal jugular (straight path, lower stenosis risk)

— Avoid subclavian (high stenosis rate destroys future ipsilateral access)

— Locked with heparin or citrate between sessions

— Catheter-related bloodstream infection (CRBSI): S. aureus (including MRSA) and gram-negatives; empiric vancomycin + cefepime/gentamicin; catheter exchange over wire vs. removal depending on organism

AV fistula creation: outpatient procedure under regional/local anesthesia; arterialized vein matures over 8–12 weeks. Endovascular AVF (WavelinQ, Ellipsys) is an emerging alternative for select anatomy.

Postoperative AVF care:

Rule of 6s for mature fistula: flow >600 mL/min, diameter >6 mm, depth <6 mm from skin, length >6 cm of cannulatable segment.

Non-maturing fistula: fistulogram → angioplasty of juxta-anastomotic stenosis (most common cause). About 30–60% of new fistulas need an assistance procedure.

AV graft: can be cannulated when swelling resolves (2–4 weeks); average patency 1–2 years; higher rates of thrombosis and infection than AVF.

Tunneled dialysis catheters (TDC):

Peritoneal dialysis catheter: placed laparoscopically; break-in period 2 weeks before use to reduce leak risk.

CCS pearl: A dialysis patient with fever, rigors during/after HD session — draw blood cultures from catheter AND peripheral, start empiric vancomycin + gram-negative coverage (cefepime or gentamicin), do not remove catheter immediately unless septic shock, tunnel infection, or persistent bacteremia >48–72 hr.

Board pearl: S. aureus bacteremia from a tunneled catheter = remove the catheter. Salvage attempts have unacceptable failure and metastatic infection rates.

Special Populations — Elderly and Hepatic Impairment

— Dialysis may not prolong survival or improve QOL vs. conservative management in patients with high comorbidity (especially ischemic heart disease, dementia, frailty)

— Functional decline is common: ~60% of nursing home residents lose independent ambulation within 1 year of starting HD

— Shared decision-making with explicit discussion of conservative management is required — Step 3 will test this

— If dialysis pursued, PD or home HD may better preserve function; in-center HD is often poorly tolerated hemodynamically

— Higher non-maturation rates for distal AVF; brachiocephalic AVF or AV graft often more practical

— Limited life expectancy may favor AVG (faster ready) or even tunneled catheter if life expectancy <1 year and access challenges

— Coagulopathy increases access bleeding risk — correct INR <1.5, platelets >50K before access creation

— PD often preferred when ascites present — drains ascites and provides dialysis simultaneously

— Avoid hepatotoxic medications; dose-adjust sedatives for procedures

— Hep B vaccine response is poor — check titers, may need additional doses

— Stop NSAIDs absolutely

— Re-dose or stop: gabapentin/pregabalin (sedation, falls), opioids (morphine and codeine metabolites accumulate — use hydromorphone or fentanyl), digoxin, sulfonylureas (glyburide contraindicated), statins (rhabdo risk if dose-inappropriate)

Elderly (>75) with advanced CKD:

Access in elderly:

Hepatic impairment / cirrhosis with CKD (hepatorenal-related or coexistent):

Polypharmacy and deprescribing:

Board pearl: The Cohen prognostic score and the "surprise question" ("Would I be surprised if this patient died in the next year?") help frame conservative care discussions. Step 3 favors offering palliative/conservative pathway alongside dialysis in frail elderly.

Step 3 management: An 82-year-old with dementia, eGFR 12, NH resident — next step is goals-of-care conversation with family, present conservative management as a valid option, not automatic dialysis access placement.

Special Populations — Pregnancy, Pediatrics, and Diabetes

— Fertility is reduced but possible; pregnancy in dialysis patients has higher rates of preterm delivery, preeclampsia, IUGR

— Dialysis intensification to >36 hours/week (often daily, longer sessions) improves outcomes — target BUN <50

— ACEi/ARBs contraindicated (teratogenic — renal dysgenesis, oligohydramnios) — switch to labetalol, nifedipine, methyldopa, or hydralazine at conception planning

— SGLT2i, finerenone, statins held in pregnancy

— ESAs continued; iron repleted aggressively

— Pregnancy timing: best after transplant, ideally 1–2 years post-transplant with stable graft function

— Growth failure prominent — growth hormone therapy

— PD often preferred for younger children (home-based, no vascular access burden)

— Preemptive transplant strongly preferred; living donor first

— Insulin requirements decrease as GFR falls (reduced renal clearance of insulin) — risk of hypoglycemia

— A1c underestimates glycemia in dialysis (anemia, ESAs, reduced RBC lifespan); target A1c ~7–8% with caution

— Diabetic vasculopathy → higher AVF non-maturation, more steal syndrome, more graft thrombosis

— SGLT2i benefit persists down to eGFR 20; metformin stops at eGFR <30

Pregnancy in CKD/dialysis:

Pediatric CKD:

Diabetes-specific considerations (the most common Step 3 CKD scenario):

Transplant candidacy considerations: age alone is not a contraindication; cancer screening up to date, active infection cleared, BMI generally <35–40, cardiac clearance.

Board pearl: A pregnant woman with CKD and rising creatinine — stop ACEi/ARB immediately, switch to labetalol/nifedipine, intensify dialysis if already on, and co-manage with MFM and nephrology.

Key distinction: In diabetic CKD, steal syndrome is more common with proximal (brachial) access — favor distal radiocephalic if vessels permit.

Complications and Adverse Outcomes

— Thrombosis: sudden loss of thrill/bruit; urgent thrombectomy (surgical or endovascular) within 24–48 hr to salvage

— Stenosis: declining flow rates, increased venous pressures during HD, prolonged bleeding post-cannulation → fistulogram + angioplasty

— Infection: AVF infections rare; AVG infections more common — IV antibiotics + possible graft excision; tunneled catheter CRBSI most common

— Aneurysm/pseudoaneurysm: from repeated cannulation; surgical revision if rapidly enlarging, skin compromise, or pain

— Steal syndrome (DASS): cold, pale, painful hand distal to access; treated with DRIL (distal revascularization-interval ligation), banding, or access ligation

— High-output cardiac failure: flow >2 L/min; banding or access revision

— Ischemic monomelic neuropathy: acute, severe — immediate access ligation

— Disequilibrium syndrome: cerebral edema from rapid urea clearance — prevented with shorter, slower initial sessions

— Hypotension during HD: most common intradialytic event — reduce ultrafiltration rate, midodrine, sodium modeling

— Cramps, arrhythmias from rapid electrolyte shifts

— Peritonitis: cloudy effluent, abdominal pain, fever; >100 WBCs/μL with >50% PMNs in effluent — empiric intraperitoneal vancomycin + cefepime

— Catheter malfunction, hernia, hydrothorax, encapsulating peritoneal sclerosis (rare, late)

Access complications:

Dialysis initiation complications:

PD complications:

Long-term CKD/dialysis complications: accelerated CV disease (#1 cause of death), calciphylaxis, secondary hyperparathyroidism, amyloidosis (β2-microglobulin), depression.

Board pearl: Calciphylaxis — painful, necrotic skin ulcers with violaceous borders in dialysis patients with elevated Ca×Phos product. Treat with IV sodium thiosulfate, aggressive phos binding, stop warfarin/calcium-based binders, wound care.

When to Escalate — Urgent Dialysis and Consults

— Acidosis: pH <7.1 refractory to bicarbonate

— Electrolytes: K⁺ >6.5 with ECG changes refractory to medical therapy

— Ingestions/intoxications: methanol, ethylene glycol, salicylate, lithium, metformin-associated lactic acidosis, theophylline ("I STUMBLE" mnemonic)

— Overload: pulmonary edema refractory to high-dose diuretics

— Uremia: pericarditis (absolute indication), encephalopathy, bleeding, intractable nausea

— Suspected access thrombosis (within 24–48 hr for salvage)

— Steal syndrome with hand ischemia

— Bleeding access (apply pressure, transfer immediately)

— Infected AV graft with sepsis

— AKI on CKD with concerning trajectory

— Refractory hyperkalemia or acidosis

— Suspected glomerulonephritis (active urinary sediment, hematuria, proteinuria + AKI)

— Hemodynamic instability + need for CRRT (continuous renal replacement therapy)

— Uremic pericardial effusion with tamponade physiology

— Severe hyperkalemia with arrhythmia

Indications for emergent/urgent dialysis (AEIOU):

Acute access for urgent dialysis: non-tunneled internal jugular catheter for immediate use; convert to tunneled catheter or use maturing AVF/AVG within days.

When to consult vascular surgery urgently:

When to consult nephrology urgently:

ICU triage:

Catheter-related sepsis with hemodynamic compromise: ICU, broad-spectrum antibiotics (vancomycin + cefepime or pip-tazo), source control with catheter removal.

CCS pearl: On a CCS scenario with K⁺ 7.2 and peaked T waves, your simultaneous orders are: IV calcium gluconate, insulin + dextrose, albuterol nebulizer, sodium bicarbonate if acidotic, place temporary HD catheter (RIJ), call nephrology stat for emergent dialysis, continuous telemetry, recheck K⁺ in 30 min. Kayexalate/patiromer are slow — not for emergencies.

Board pearl: Uremic pericarditis is an absolute indication for urgent dialysis — and avoid heparin during the dialysis session due to risk of hemorrhagic conversion/tamponade.

Key Differentials — Same-Category Causes of Declining Renal Function

— Volume depletion (diuretic overuse, GI losses)

— NSAIDs, ACEi/ARB initiation (functional, often reversible)

— Decompensated heart failure (cardiorenal syndrome)

— Acute interstitial nephritis (AIN): new medication (PPI, NSAID, antibiotic, checkpoint inhibitor); pyuria, eosinophiluria, WBC casts

— Acute tubular necrosis (ATN): ischemic, contrast, rhabdomyolysis

— Glomerulonephritis flare: active sediment (dysmorphic RBCs, RBC casts, proteinuria) — workup with serologies (ANA, ANCA, anti-GBM, complements, hepatitis), kidney biopsy

— Thrombotic microangiopathy: schistocytes, thrombocytopenia, LDH ↑

— Obstruction — always rule out with renal US in any unexplained AKI on CKD (BPH, stones, retroperitoneal fibrosis, malignancy)

— Uncontrolled HTN, uncontrolled diabetes, ongoing albuminuria, repeated AKI episodes, smoking, obesity

Before committing a CKD patient to dialysis prep, rule out reversible causes of GFR decline:

Prerenal/hemodynamic insults:

Intrinsic causes superimposed on CKD:

Postrenal:

CKD progression accelerators:

Step 3 management: Stage 4 CKD patient with eGFR drop from 25 to 15 over 2 weeks — next step is renal US to exclude obstruction, urinalysis, med review (especially new NSAIDs, PPIs, contrast exposure), and assess volume status. Do not skip straight to dialysis access — reversible causes first.

Board pearl: In a CKD patient with rapid GFR decline + active sediment, kidney biopsy may still be indicated even in advanced disease if it would change management (immunosuppression for vasculitis, lupus nephritis). Biopsy risk rises with smaller, scarred kidneys (<9 cm) — discuss with nephrology.

Key distinction: AKI on CKD is potentially reversible; CKD progression is gradual. Slope of decline + sediment + imaging differentiate.

Key Differentials — Other-Category Mimics and Confounders

Mimics of "need for dialysis" that are not actually ESRD:

Hepatorenal syndrome (HRS-AKI): cirrhosis + AKI without other identifiable cause; treated with albumin + terlipressin/octreotide+midodrine, NOT primarily dialysis. Bridge to liver transplant.

Cardiorenal syndrome: decompensated HF with low cardiac output → renal hypoperfusion; aggressive diuresis, optimization of HF therapy, ultrafiltration if diuretic-resistant; not necessarily chronic dialysis.

Severe hyponatremia, hypernatremia, hypercalcemia mimicking uremic encephalopathy.

Thrombotic thrombocytopenic purpura (TTP) or atypical HUS: AKI + thrombocytopenia + MAHA — needs plasma exchange (TTP) or eculizumab (aHUS), not dialysis as primary therapy.

Multiple myeloma / cast nephropathy: elderly patient with AKI, anemia, hypercalcemia, bone pain, anion gap narrowing — SPEP/UPEP, free light chains, chemotherapy ± plasma exchange alongside dialysis support.

Tumor lysis syndrome: post-chemotherapy hyperuricemia, hyperphosphatemia, hyperkalemia — rasburicase, aggressive hydration, dialysis if severe.

Lithium, methanol, ethylene glycol, salicylate toxicity — dialysis is therapeutic for the toxin, not for chronic ESRD.

Pseudo-renal failure: drugs that ↑ creatinine without affecting GFR (trimethoprim, cimetidine, cobicistat, dolutegravir) — check cystatin C to confirm.

Board pearl: A cirrhotic with AKI, urine Na <10, no improvement with albumin challenge → hepatorenal syndrome type 1. Initiate terlipressin + albumin; dialysis only as bridge in liver transplant candidates — it does not change outcome in non-candidates.

Step 3 management: Always ask "is this reversible" before placing access. A confused workup of cause = wrong dialysis decision = harm.

Secondary Prevention, Discharge Meds, and Long-Term Plan

— Phosphate binder with each meal (sevelamer, lanthanum, ferric citrate, or calcium acetate if low Ca)

— Active vitamin D analog (calcitriol/paricalcitol) if iPTH elevated

— ESA with iron repletion if Hgb <10

— Renal multivitamin (water-soluble vitamins lost during dialysis; avoid vitamin A — accumulates)

— Statin if previously on one (continue); do not newly initiate after dialysis start

— Antihypertensives dosed around dialysis (hold morning antihypertensives on HD days to avoid intradialytic hypotension; carvedilol, lisinopril preferred)

— Antiplatelet per CV indication

— Continue SGLT2i until dialysis initiation, then discontinue

— Hep B series (double-dose 40 mcg, check anti-HBs titer; revaccinate if <10)

— PCV20 (or PCV15 → PPSV23 sequence)

— Annual influenza, COVID boosters

— Tdap, zoster (recombinant), RSV (≥60)

— Sodium <2 g/day, potassium individualized (more liberal on PD), phosphorus 800–1000 mg/day, protein 1.0–1.2 g/kg/day on dialysis (higher than pre-dialysis)

— Renal dietitian consult is non-negotiable

— Listing at eGFR ≤20; encourage living donor identification (better outcomes, shorter wait, preemptive option)

— Annual re-evaluation while on waitlist

Discharge medication checklist for the patient initiating dialysis or post-access creation:

Vaccinations to complete:

Diet:

Transplant pathway:

Cardiovascular prevention: BP target <120/80 (per KDIGO 2021, individualized), tobacco cessation, statin if appropriate, glycemic control.

Board pearl: Hold ACEi/ARB on HD mornings, but continue chronically if BP and K tolerate — they remain renoprotective for residual kidney function, which is precious in early dialysis and especially in PD.

Step 3 management: Every dialysis patient leaves the unit with a documented transplant referral status, advance directive, and modality reassessment plan every 6–12 months.

Follow-Up, Monitoring, and Counseling

— eGFR 30–45: nephrology every 6 months

— eGFR 15–30: every 3 months

— eGFR <15: monthly, with active dialysis planning

— 2 weeks: wound check, thrill assessment

— 4–6 weeks: duplex US to assess maturation

— 8–12 weeks: clinical assessment for cannulation readiness

— Surveillance after cannulation: monitor access flow (Qa), recirculation, venous pressures monthly; fistulogram for declining flow <600 mL/min or >25% drop

— Monthly: CBC, BMP, Ca/Phos/PTH (quarterly), iron studies, albumin, Kt/V (dialysis adequacy, target ≥1.2 for HD, weekly ≥1.7 for PD)

— Annual: hep B/C/HIV serologies, PPD/IGRA per transplant status, cardiac assessment

— Dialysis access exam every session

— Access protection: no BPs, IVs, jewelry on access arm; immediate report if no thrill

— Fluid restriction: typically 1–1.5 L/day on HD; weight gain <3–5% between sessions

— Dietary education: potassium, phosphorus, sodium; avoid star fruit (neurotoxic), limit processed foods (hidden phosphate additives — most bioavailable form)

— Adherence to dialysis schedule: missing sessions is a leading cause of hyperkalemic death

— Depression screening (PHQ-9) annually — prevalence ~25% in dialysis patients

— Sexual health, fertility, pregnancy planning discussion

Outpatient follow-up cadence for advanced CKD pre-dialysis:

Post-access creation follow-up:

On dialysis — routine monitoring:

Counseling priorities:

Rehabilitation: PT for deconditioning, intradialytic exercise programs improve function and survival.

Board pearl: Kt/V <1.2 in HD or <1.7/week in PD = inadequate dialysis → increase dialysis time, frequency, or blood/dialysate flow.

Step 3 management: A dialysis patient missing sessions presents with K⁺ 7.0 — counsel on adherence, screen for depression and financial/transport barriers, involve social work; this is a systems-level patient safety issue.

Ethical, Legal, and Patient Safety Considerations

— Must include conservative (non-dialytic) management as a legitimate option, especially in elderly/frail patients — failure to offer this is increasingly considered a quality and ethical lapse

— Must discuss expected QOL, time commitment, complications, life expectancy (median ~5 years on HD overall, lower in elderly)

— Modality choice (HD vs. PD vs. transplant vs. conservative) should be shared decision-making

— Patients with decision-making capacity have the right to withdraw from dialysis; this is ethically and legally distinct from physician-assisted dying

— Median survival after withdrawal ~8–10 days; palliative care/hospice referral mandatory

— For patients lacking capacity, use advance directives, surrogate decision-makers, and assess best interests

— Discharge after access creation: clear return precautions (loss of thrill, bleeding, hand ischemia, fever) and follow-up appointment before discharge

— Hospital → outpatient HD unit handoff: medication reconciliation (especially anticoagulants, antibiotics with renal dosing, dry weight)

— Avoid PICC lines, midlines, and subclavian central lines in any CKD stage 4–5 patient — preserves future access (a "save the vein" alert in the EMR is a recognized patient safety intervention)

— Suspected elder abuse or neglect in a dialysis-dependent patient (missed sessions, malnutrition) → APS referral

— Driving safety: post-HD hypotension and fatigue impair driving for several hours; counsel patients

Informed consent for dialysis initiation:

Withdrawal from dialysis:

Transitions of care — high-risk Step 3 patient safety zone:

Mandatory reporting / system issues:

Health equity: Black, Hispanic, and low-income patients have lower rates of preemptive transplant and AVF use, higher catheter use — Step 3 may probe systemic disparities and asks you to address access barriers.

Board pearl: A 78-year-old with dementia whose family demands dialysis despite the patient's prior advance directive declining it — the advance directive prevails; engage palliative care and ethics committee.

Step 3 management: Document goals-of-care conversation at every modality transition; this is both an ethical and a billable quality metric.

High-Yield Associations and Rapid-Fire Facts

AVF maturation rule of 6s: flow >600 mL/min, diameter >6 mm, depth <6 mm, 6 cm cannulatable length, by 6 weeks.

Fistula first, catheter last — every Step 3 question about access asks this.

Hep B vaccine dose in CKD: double dose (40 mcg); check titers; revaccinate if anti-HBs <10.

Hgb target on ESA: 10–11 g/dL — never normalize.

eGFR <20: list for transplant. eGFR <15–20: place AVF. eGFR symptoms (not number): start dialysis.

Median AVF maturation: 8–12 weeks; AVG: 2–4 weeks; catheter: same day but worst.

PD preferred: severe heart failure, poor vessels, desire for autonomy, young/employed patients, in resource-limited settings.

Steal syndrome: cold, painful, pale distal hand — urgent vascular surgery.

Calciphylaxis: painful necrotic skin lesions, elevated Ca×Phos, often on warfarin → sodium thiosulfate, stop warfarin/calcium binders.

Disequilibrium syndrome: cerebral edema with rapid initial dialysis — shorter, slower first sessions.

Uremic pericarditis: absolute indication for urgent dialysis; no heparin during sessions.

Beta-2-microglobulin amyloidosis: carpal tunnel, shoulder pain, cysts in long-term HD patients.

Avoid in CKD: NSAIDs (always), gadolinium <30 (NSF), phosphate bowel preps, metformin <30, glyburide, morphine/codeine.

Best modality for survival: preemptive living-donor kidney transplant.

Worst access for outcomes: tunneled cuffed catheter.

Right IJ is the preferred catheter site; never subclavian in CKD.

Vein preservation: non-dominant arm protected from BPs, IVs, venipuncture once CKD stage 3b–4.

K+ emergency: calcium → insulin/D50 → albuterol → bicarb (if acidotic) → dialysis (definitive).

Statin rule: start in pre-dialysis CKD; don't initiate de novo in incident dialysis.

Cause of death #1 in dialysis: cardiovascular, not uremia.

Board pearl: The single best predictor of AVF non-maturation is small vein diameter on preoperative mapping (<2.5 mm) — vein mapping is mandatory.

Board Question Stem Patterns

Stem 1 — Vein preservation: "56-year-old man with eGFR 22 admitted for cellulitis. Nurse asks where to place IV." → Right hand or dominant arm; protect non-dominant arm for future AVF.

Stem 2 — Modality choice: "68-year-old with EF 20%, eGFR 14, symptomatic." → PD (avoids hemodynamic shifts and high-output failure from AVF).

Stem 3 — When to place access: "62-year-old diabetic, eGFR 18, declining 4 mL/min/year, asymptomatic." → Refer for AVF creation now in non-dominant arm.

Stem 4 — Pulsatile fistula: "Dialysis tech notes fistula is hyperpulsatile, bleeding prolonged post-cannulation." → Outflow stenosis; fistulogram + angioplasty.

Stem 5 — Loss of thrill: "Patient missed HD, comes with arm fistula that has no thrill or bruit." → Acute thrombosis; urgent vascular surgery for thrombectomy.

Stem 6 — Fever in HD patient: "Tunneled catheter HD patient with rigors during session." → Blood cultures from catheter and peripheral, empiric vancomycin + cefepime/gentamicin.

Stem 7 — Hand ischemia post-access: "1 week post-brachial AVF, cold pale painful hand." → Steal syndrome; urgent vascular surgery (DRIL or banding).

Stem 8 — Pregnant CKD: "30-year-old, eGFR 35, on lisinopril, newly pregnant." → Stop ACEi, switch to labetalol/nifedipine.

Stem 9 — Uremic pericarditis: "Friction rub, eGFR 8, pleuritic chest pain." → Urgent dialysis without heparin.

Stem 10 — Elderly conservative care: "85-year-old NH resident with dementia, eGFR 12, family asks about dialysis." → Goals-of-care discussion, offer conservative management.

Stem 11 — Anemia management: "CKD stage 4, Hgb 8.5, TSAT 15%, ferritin 70." → IV iron first, then consider ESA.

Stem 12 — Hyperkalemia on ACEi: "K 5.6 on lisinopril, eGFR 25." → Add patiromer/SZC; continue ACEi for renoprotection.

Stem 13 — Wrong-site catheter: "Patient needs urgent HD; resident wants to place subclavian line." → Place right IJ; avoid subclavian to preserve future access.

Board pearl: Most Step 3 stems will reward the earliest, least-invasive correct action — vein preservation, early nephrology referral, vein mapping, AVF over catheter.

One-Line Recap

Dialysis preparation in CKD is a longitudinal outpatient program: early nephrology referral, vein preservation, modality education, transplant listing at eGFR ≤20, and AV fistula creation 6–12 months before anticipated dialysis — because every shortcut (late referral, central catheter, subclavian access) costs the patient years of life.

eGFR 30 = refer nephrology; eGFR 20 = list for transplant; eGFR 15–20 + progressive = place AVF; symptoms = start dialysis.

Access hierarchy: radiocephalic AVF → brachiocephalic AVF → basilic transposition → AV graft → tunneled catheter (last resort, worst survival).

Vein preservation is a quality and safety mandate: no IVs, BPs, PICCs, or subclavian lines in the non-dominant arm of any CKD stage 4–5 patient; complete hep B (double-dose) and pneumococcal vaccination before dialysis initiation; replete iron before ESAs and target Hgb 10–11 (never normalize).

Conservative (non-dialytic) management is a legitimate, often preferable option for frail elderly with multimorbidity and must be offered as part of informed consent — Step 3 will frame goals-of-care conversations, advance directive adherence, and shared decision-making as the right answer over reflexive access placement.

Emergencies: uremic pericarditis, refractory hyperkalemia, refractory acidosis, refractory volume overload, encephalopathy, and dialyzable toxin ingestion are absolute indications for urgent dialysis — use right IJ non-tunneled catheter as bridge, never subclavian.

Board pearl: The two interventions that most improve long-term dialysis survival are early nephrology referral (>90 days before initiation) and starting dialysis with a functioning AV fistula rather than a catheter — both are entirely upstream, outpatient, primary-care-adjacent decisions, which is exactly why Step 3 loves this topic.