🏠 Study Hub 🖼️ Infographics
Nursing Field Notes / Renal + Fluid · Pathophysiology Course

Renal Failure 🧪
Labs & Symptoms

Acute vs. Chronic — part 2 of 3 · every lab value next to the symptom it causes

NG-265 Renal + Fluid ADHD-friendly visual edition

THE LAB & SYMPTOM PAGE. Every number lined up beside the sign it produces, plus the top 2 missed NCLEX questions — both about potassium. Sisters: NG-047 = master overview & causes · NG-264 = the 4 phases & 5 stages · NG-266 = nursing care, diet & drugs.

📄 Simple Nursing original — opens in Drive →

🫀 K⁺ over 5.0 = PRIORITYPotassium Pumps the heart. It kills first, so you treat it first.
📈 Peak → ST → WidePeaked T 6–7 · ST elevation 7–8 · wide QRS >8
🧺 Broken washing machineNa⁺ · K⁺ · phosphorus · urea · acid all stay in the blood
🩸 Anemia is EXPECTEDNo kidney → no erythropoietin → no red cells
🧪

THE LABS

STEP 1 · THE NUMBERS

A failing kidney is a broken washing machine — nothing gets rinsed out, so everything piles up in the blood.

🧺 Excess waste & electrolytes in the blood — the broken washing machine

🧺 THE WASHER IS BROKEN — nothing rinses out ⚠️ ERROR — NO DRAIN FULL OF DIRTY BLOOD the failing kidney 🧂 Na⁺ SODIUM stays → water follows salt → edema, high BP, weight gain 🫀 K⁺ POTASSIUM stays → peaked T waves, dysrhythmias, cardiac arrest — THE KILLER 🦴 PHOSPHORUS stays → calcium falls → itching, brittle bones, muscle cramps 💩 UREA stays → UREMIA: uremic frost, pruritus, metallic taste, confusion 🧪 H⁺ IONS (ACID) stay → metabolic ACIDosis, pH below 7.35, Kussmaul breathing
🧠 “SPUKA in the wash” — Sodium · Phosphorus · Urea · K⁺ · Acid. Five things that should have gone down the drain and didn't. Every renal symptom is one of these five backing up.

🧪 The renal lab panel — normals on the left, renal failure on the right

LabNormal (adult, typical)Renal failure
Potassium K⁺ 🫀3.5–5.0 mEq/LHIGH — over 5.0. Treat first.
Sodium Na⁺ 🧂135–145 mEq/LRetained (source: HIGH). Note: because water is held too, the serum value often reads normal or even low — total body sodium is still high.
Phosphorus 🦴3.0–4.5 mg/dLHIGH
Calcium 🦴≈8.6–10.2 mg/dL (varies by lab)LOW — phosphorus rises, calcium falls; no activated vitamin D
Magnesium 💊1.3–2.1 mEq/LHIGH — that's why magnesium antacids are banned
BUN 💩10–20 mg/dLOver 20
Creatinine 🧪0.6–1.2 mg/dLOver 1.3 = bad kidney
pH 🫁7.35–7.45Below 7.35 = metabolic ACIDosis (bicarb also low)
Hgb / Hct · RBCs 🩸Hgb 12–16 g/dL ♀ · 14–18 ♂LOW — anemia, no erythropoietin
GFR 📉>90 mL/minFalls stage by stage; <15 = ESRD
Urine output 🚽1500 mL/24 hr · 30 mL/hr minOliguria — under 400 mL/24 hr
🧠 Everything goes UP except calcium, hemoglobin, pH and urine. Four things go DOWN — “Ca, Hgb, pH, pee.” Learn the four exceptions and the rest is automatic.

📊 See the directions at a glance

📊 WHICH WAY DOES IT MOVE? NORMAL ◀ LOW HIGH ▶ K⁺ >5.0 🚨 Phos >4.5 Mg >2.1 BUN >20 Creat >1.3 Na⁺ (body) retained Calcium LOW Hgb/Hct anemia pH · urine <7.35 · <400 mL
🧠 Picture a seesaw: phosphorus UP forces calcium DOWN. They are always opposite — if the exam says phos is high, calcium is low, and the patient itches.
🔎

THE SIGNS

STEP 2 · WHAT YOU SEE

Head to toe, every symptom traces back to one lab on the page above.

🧍 Head-to-toe map of uremia & overload

🧍 WHERE UREMIA SHOWS UP pitting edema 🧠 Confusion · lethargy asterixis, seizures — uremic encephalopathy 👅 Metallic taste · ammonia breath anorexia, nausea, vomiting 🫁 CRACKLES — wet, fluid-filled lungs Kussmaul breathing blows off acid 🫀 Hypertension · bounding pulses dysrhythmias · pericardial friction rub 🚨 🩸 Anemia — pale, tired, short of breath easy bruising & bleeding too 🤕 HEADACHE think hypertensive crisis 🦢 JVD — jugular vein distention neck veins bulge from the fluid excess ❄️ UREMIC FROST white urea crystals on the skin 🤲 PRURITUS — relentless itching urea + high phosphorus in the skin 🦴 Brittle bones · cramps low calcium, renal osteodystrophy ⚖️ Weight UP 1 kg gained = 1 L of fluid retained
🧠 “Frosty, itchy, tired, wet.” Four words = the classic chronic renal patient: uremic frost, itching, anemic fatigue, and fluid-wet lungs.

🫀 HIGH POTASSIUM — over 5.0 · the 3 P's

MEMORY TRICK — 3 P's: Potassium is a Priority since it Pumps the HEART muscles.

High potassium changes how the heart's muscle cells fire — “HIGH PUMPS in the heart” — producing peaked T waves & ST elevation, then wide QRS, then arrest.

📈 THE POTASSIUM LADDER ON THE MONITOR ✅ K⁺ 3.5–5.0 · NORMAL P wave · narrow QRS · rounded T ⚠️ K⁺ 6–7 · PEAKED T WAVES tall, tented, narrow T — first ECG change 🔺 K⁺ 7–8 · ST ELEVATION ST segment lifts · P wave flattens or disappears 🚨 K⁺ OVER 8 · WIDE QRS → SINE WAVE QRS smears into the T — next stop is arrest

EXAM TIP The ECG picture tells you how urgent it is. Peaked T = get moving. Wide QRS = move NOW.

🧠 “Tall Tents, Steep Steps, Wide Waves.” 6–7 tall tented T · 7–8 ST steps up · over 8 the QRS goes wide. Higher K⁺ = uglier, wider, deader.

🚱 Oliguria — LOW urine output

Kaplan question: “Patient with chronic kidney disease?” → Oliguria is EXPECTED.

Don't pick oliguria as the "unexpected/report immediately" answer in a known CKD patient — it's the disease doing exactly what the disease does. Report the new or life-threatening finding instead.

🧠 Expected ≠ emergency. In CKD, low urine is the baseline. The emergency is what the retained potassium and fluid are doing to the heart and lungs.

🩸 Anemia — LOW RBCs

Answer first: the kidneys release erythropoietin, the hormone that stimulates bone marrow to produce red blood cells. No kidney → no EPO → no red cells.

  • 😮‍💨 Fatigue, pallor, dyspnea on exertion, tachycardia
  • 💊 Treated with epoetin alfa / darbepoetin + iron
  • 🩸 Bleeding risk is up too — uremia makes platelets sluggish
🩸 THE BROKEN EPO CHAIN damaged kidney no EPO BONE MARROW gets no signal few RBCs = ANEMIA kidney → EPO → marrow → red cells → oxygen
🧠 EPO = “Every Person's Oxygen.” Kidneys don't just make urine — they order the red cells that carry oxygen.

🚨 Critical complication: Fluid Volume Overload (FVO)

🫁CRACKLESwet, fluid-filled lungs
🦢JVDjugular vein distention
💥BOUNDING pulsesfrom that fluid excess
⚖️Weight UP1 kg = 1 L retained
🦵Pitting edemalegs, sacrum
🩸BP UPhypertension
😮‍💨Dyspnea · orthopneacan't lie flat
🫀S3 gallopoverloaded heart

Priority action: raise the head of the bed, oxygen, assess lung sounds, hold fluids, notify the provider — loop diuretic if the kidneys still make urine, dialysis if they don't.

🧠 “Wet lungs, fat neck, big pulse.” Three findings in a row = FVO. Contrast with FVD (dry): flat neck veins, thready pulse, weight down.

🚨 Critical complication: Hypertensive crisis — Priority key signs!

1
🤕 Headache — often the very first complaint
2
🤢 Nausea & vomiting
3
🧠 Change in mental status — confusion, blurred vision, restlessness

Why it happens: retained sodium and water expand the volume, and damaged kidneys keep pumping out renin — pressure climbs until vessels in the brain, eyes and heart are at risk.

Act on it: that triad in a renal patient is a report-now finding, not a "recheck in an hour" finding.

🧠 “Head, Hurl, Haze.” Headache → hurling → hazy thinking. Three H's climbing the BP ladder = hypertensive crisis.
🚨

PRIORITY TREATMENT

STEP 3 · WHAT FIRST

These are the top 2 missed NCLEX questions — and both are decided by one thing: is the HEART already changing?

⚡ The hyperkalemia order — and the rule that decides #1

Answer first: ECG changes present → IV calcium gluconate FIRST (it protects the heart muscle). No ECG changes → shift the potassium with IV insulin + dextrose.

1
💉 IV Calcium Gluconate — for dysrhythmias. Stabilizes the heart membrane in minutes. Does NOT lower the K⁺ level — it just buys time.
▼
2
💉 IV 50% Dextrose + Regular insulin — pushes K⁺ out of the blood and into the cells. Works in ~15–30 min. Only regular insulin goes IV. Watch for hypoglycemia.
▼
3
💊 Kayexalate (sodium polystyrene sulfonate) — removes K⁺ through the stool. Slow — hours. Expect diarrhea; that's the drug working.
▼
4
🩸 Dialysis — the definitive fix. Takes the potassium out of the body for good.

Why the order works: protect the heart → hide the potassium in the cells → remove it from the gut → remove it from the body.

🧠 MEMORY TRICK: “GLUCONATE GLUES down heart muscles.” Then “Insulin drives K into the cell 🚗, Kayexalate poops it out 💩, Dialysis takes it away 🧳.” Protect · Push · Poop · Pull.

⭐ Top 2 missed NCLEX questions — worked through

Q · End stage renal diseaseQ · Missed 3 dialysis sessions
K⁺ 7.2, BUN 35, creatinine 3.8, urine output 300 mL in 24 hr. Which order is PRIORITY? K⁺ 8.1, WIDE QRS complexes, HR 58, lethargy. Which order does the nurse implement FIRST?
Choices: IV 50% dextrose & regular insulin · sodium polystyrene sulfonate · hemodialysis · IV calcium gluconate Same menu of choices — but the heart is already changing.
✅ IV 50% Dextrose & regular insulin — no dysrhythmia is described, so shift the potassium fastest. ✅ IV calcium gluconate — wide QRS + bradycardia = dysrhythmia now. Stabilize the heart first, then shift and remove.

EXAM TIP Scan the stem for wide QRS · peaked T · bradycardia · “weak, lethargic” with K⁺ 8.5. Any of those = calcium gluconate is the first action.

🧠 “Squiggle = Gluconate.” If the question shows you a squiggly, sick-looking heart — wide QRS, slow rate — glue the heart down first. No squiggle? Insulin + dextrose.

🧠 The trick question: chronic renal failure order list

Source's list for chronic renal failure: 1. IV regular insulin & 50% dextrose · 2. IV loop diuretic · 3. Dialysis · 4. “Put in for vacation time?”

The joke is the teaching point: the fourth option is a distractor. Renal questions always hide one obviously wrong choice — eliminate it first, then rank the three real ones by who protects the heart soonest.

🧠 Loop diuretics only work if there's a working nephron. In ESRD with no urine, a loop diuretic is nearly useless — that's when the answer becomes dialysis.

✅ What you do at the bedside, right now

  • 🫀 Cardiac monitor on any K⁺ over 5.0
  • 🧪 Recheck the K⁺ — and ask if the sample was hemolyzed (falsely high)
  • 🚫 Stop all potassium: IV fluids with K, salt substitutes, K-sparing diuretics
  • 📋 Review meds for ACE inhibitors / ARBs / NSAIDs that raise K⁺
  • 📞 Notify the provider with the level AND the rhythm — both drive the order
🧠 Level + Rhythm = the whole report. Never call with just a number; the ECG is what picks the drug.
⚡

QUICK RECALL

SAY IT OUT LOUD
3️⃣ The 3 P'sPotassium · Priority · Pumps the heart
💉 Squiggle = GluconateECG changes → calcium gluconate FIRST
🧺 SPUKA backs upSodium · Phosphorus · Urea · K⁺ · Acid
🤕 Head · Hurl · Haze= hypertensive crisis · report now
🎯 Cover & check — 7 rapid-fire questions
Q1: Why is potassium the priority electrolyte in renal failure?
The 3 P's — Potassium is a Priority since it Pumps the HEART muscles. High K⁺ (over 5.0) causes peaked T waves, ST elevation, wide QRS and cardiac arrest.
Q2: Match the K⁺ level to the ECG change.
Peaked T waves: 6–7 mEq/L · ST elevation: 7–8 mEq/L · Wide QRS complex: over 8 mEq/L. Normal K⁺ is 3.5–5.0.
Q3: K⁺ 8.5 mEq/L in a client with kidney disease who is weak, lethargic and bradycardic. First order?
IV calcium gluconate — for dysrhythmias. GLUCONATE GLUES down heart muscles. It stabilizes the myocardium but does NOT lower the potassium, so insulin + dextrose, Kayexalate and dialysis still follow.
Q4: Name the four steps of hyperkalemia treatment in order.
1. IV calcium gluconate (for dysrhythmias) · 2. IV 50% dextrose + regular insulin · 3. Kayexalate (sodium polystyrene sulfonate) · 4. Dialysis. Protect · Push · Poop · Pull.
Q5: Which electrolytes go HIGH in renal failure, and which go LOW?
HIGH: potassium (norm 3.5–5.0), phosphorus (norm 3.0–4.5), magnesium, and retained sodium (norm 135–145) with water. LOW: calcium, hemoglobin/hematocrit, pH (below 7.35) and urine output.
Q6: Why is a client with CKD anemic?
The kidneys release erythropoietin, the hormone that stimulates bone marrow to produce red blood cells. Damaged kidneys make less EPO, so RBCs drop.
Q7: Name three signs of fluid volume overload in a renal patient.
Crackles in the lungs (wet, fluid-filled lungs), JVD — jugular vein distention, and bounding pulses from that fluid excess. Plus weight gain (1 kg = 1 L), edema and hypertension.