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Nursing Field Notes / Renal + Fluid · Pharmacology

Vitamins & Electrolytes 💊

Iron · Folic acid · B12 · Potassium · Magnesium sulfate

NG-227 RENAL + FLUID ADHD-friendly visual edition

Five replacements, three jobs. Iron, folic acid and B12 BUILD the blood 🩸 · Potassium PUMPS the heart ⚡ · Magnesium MELLOWS the muscles 🧲. Every one of them is tested the same way: what does it do, what will hurt the client, and what do you teach?

📄 Simple Nursing original — opens in Drive →

⬛ Black stools = NORMALFerrous sulfate turns stool dark/black. Expected — NOT a GI bleed.
🚨 NEVER push potassium= DEATH. Monitor first · diluted · IV pump · 10–20 mEq/hr max.
🛑 STOP the mag dripif RR < 12 · DTRs decreased/absent · urine < 30 mL/hr. Antidote = calcium gluconate.
🍊 Vitamin C boosts ironOrange/fruit juice ⬆ absorption · calcium & dairy BLOCK it.
🩸

THE BLOOD BUILDERS

STEP 1 · WHAT THEY DO

Three building blocks make a red blood cell — iron, folic acid, B12. Miss one and the client is anemic.

🧱 The three building blocks of a red blood cell

🧱 Patients who lack the building blocks to make RBCs 🧲 IRON ferrous sulfate 🥬 FOLIC ACID folate · B9 💉 B12 HEALTHY RBC carries oxygen to every cell missing any ONE? = ANEMIA fatigue · pallor shortness of breath tachycardia · dizziness low blood cell count
🧠 “I Feed Blood” — Iron · Folic acid · B12. Three ingredients, one red blood cell. Any missing ingredient = anemia.

💊 IRON — ferrous sulfate (oral) & iron dextran (IV/IM)

WHAT IT DOES Treats anemia related to iron deficiency. Iron is the part of hemoglobin that actually grabs the oxygen.

🧲 Getting iron IN — and what blocks it STOMACH → small intestine empty is best ✅ BOOSTS ABSORPTION 🍊 Orange juice / fruit juice 🍋 Vitamin C (ascorbic acid) ⏱️ Empty stomach — 1 HOUR before other meds 🥩 Meat, fish, poultry 🚫 BLOCKS ABSORPTION 🦴 CALCIUM 🥛 Dairy — milk, cheese 🧴 Antacids & PPIs ☕ Coffee · 🍵 tea 🌾 Large amounts of bran

WATCH FOR

  • ⬛ Dark or black stools = NORMAL & EXPECTED — NOT a GI bleed HESI Do not stop the drug and do not report it as bleeding.
  • 🚽 Constipation — increase fiber and fluids; a stool softener may be ordered
  • 🤢 Nausea, epigastric pain, metallic taste
  • 😬 Liquid iron stains teeth — dilute it and drink through a straw, then rinse the mouth
  • 💉 Iron dextran IM — Z-track technique in a large muscle, do not massage the site; risk of anaphylaxis, so a test dose and emergency equipment are used
  • 🧒 Iron overdose is a leading cause of poisoning death in small children — store it locked and out of reach

TEACH

  • ⏱️ Take on an empty stomach, 1 hour before other medications; if GI upset is severe, take with a small amount of food, knowing absorption drops
  • 🍊 Take with orange juice or vitamin C; separate from calcium, dairy and antacids by ~2 hours
  • ✅ Teaching is effective when the client says: “I will eat more fresh fruits and whole grain bread.” HESI
  • 📈 Expect several weeks before the hemoglobin rises; finish the full course
🧠 “Iron loves C, hates Ca.” Vitamin C carries iron in · Calcium slams the door. And black stool is the iron leaving, not the client bleeding.

🥬 FOLIC ACID (folate · B9)

WHAT IT DOES Treats anemia (low blood cell count) and prevents neural tube defects in pregnancy.

WATCH FOR

  • 💊 SULFA drugs decrease folic acid absorption — sulfasalazine especially. A client on sulfa drugs needs a folic acid supplement. CAUTION
  • 🧠 Folic acid corrects the anemia of B12 deficiency but does NOT fix the neurologic damage — a classic trap
  • 💊 Also depleted by methotrexate, phenytoin and alcohol

TEACH

  • 🤰 Start BEFORE pregnancy — the neural tube closes in the first weeks, often before a person knows they are pregnant. HESI · pregnant clients
  • 💊 400 mcg (0.4 mg)/day is the standard preconception dose; higher prescription doses (commonly 1 mg/day) are used to treat deficiency — take the dose as prescribed
  • 🥗 Food sources: dark leafy greens, fortified whole grain bread & cereal, beans, citrus, liver
🧠 “FOLiage = FOLate.” Leafy green foliage is folate — and Sulfa Steals it, so Supplement.

💉 VITAMIN B12 — cyanocobalamin

WHAT IT DOES Treats pernicious anemia — the body lacks INTRINSIC FACTOR, so it cannot absorb B12.

WATCH FOR

  • 🧠 Neurologic signs are the giveaway: numbness & tingling of hands/feet, unsteady gait, memory loss, confusion
  • 👅 Beefy red, sore, smooth tongue (glossitis) and pallor
  • 🩺 Other causes: gastrectomy / gastric bypass, ileal resection, Crohn's, strict vegan diet, long-term metformin or PPIs

TEACH

  • 💉 Without intrinsic factor, ORAL B12 will not be absorbed — replacement is lifelong IM (or intranasal) B12, usually monthly
  • ♾️ Lifelong means lifelong — stopping it lets the neuro damage return and it may become permanent
  • 🥩 Food sources: meat, fish, eggs, dairy, fortified cereals
🧠 “No factor, no absorption — so give the shot.” Intrinsic factor is the key; B12 is the car. No key → you cannot drive it in through the gut, so you inject it.

🔬 Why pernicious anemia needs an injection — follow the intrinsic factor

✅ NORMAL ABSORPTION B12 swallowed stomach IF intrinsic factor made by parietal cells ileum B12 absorbed ✅ 🚫 PERNICIOUS ANEMIA B12 oral B12 NO intrinsic factor → B12 passes straight through 💉 IM B12 bypasses the gut — LIFELONG → blood
🧠 “Pernicious = permanent shots.” The stomach lost the key, so the gut route is closed forever — the needle is the only door left.
⚡

POTASSIUM · K⁺

STEP 2 · WATCH FOR — THE DEADLIEST REPLACEMENT

Potassium PUMPS the heart. Every question about it is really a question about the infusion rules.

🧪 Potassium value scale

NORMAL 3.5 – 5.0 mEq/LCRITICAL ≤2.5 or ≥6.5
⚡ POTASSIUM (K⁺) units: mEq/L · “Potassium PUMPS the heart” 3.5–5.0 ≤2.5 CRIT LOW 2.6–3.4 HYPOkalemia 3.5–5.0 NORMAL 5.1–6.4 HYPERkalemia ≥6.5 CRIT HIGH Supplement is indicated for hypokalemia — below 3.5. Critical cutoffs vary by lab — verify your facility list.
🧠 “3.5 to 5 keeps you alive.” Below 3.5 you replace it. Above 5.0 you remove it. Never both at once.

📉 HYPOkalemia — below 3.5 · low & slow

  • 🫁 Shallow respirations — the most deadly sign
  • 🔨 Decreased DTR, muscle cramps, flaccid paralysis, fatigue
  • 🚽 Constipation, hypoactive bowel sounds, paralytic ileus
  • 🫀 Flat T waves · ST depression · U waves, PVCs
  • 💊 Increases digoxin toxicity risk

Top causes: K⁺-wasting diuretics, vomiting/diarrhea, NG suction, poor intake, DKA/insulin, hyperaldosteronism.

🧠 “Low K = everything sags” — sagging T waves, sagging gut, sagging limbs. Only the U wave pops up.

📈 HYPERkalemia — over 5.0 · high & tight

  • 🫀 PEAKED T waves → widened QRS → V-fib & cardiac arrest; bradycardia & hypotension
  • 💪 Tingling/paresthesia → paralysis & muscle heaviness
  • 🚽 Diarrhea, hyperactive bowel sounds

Top causes: renal failure, K⁺-sparing drugs (spironolactone, -prils, -sartans), cell death (crush/burns/tumor lysis), acidosis, salt substitutes.

Never give a potassium supplement to a client whose K⁺ is already at or above 5.0.

🧠 “Tents on the monitor = too much K⁺.” Tall, tented T waves are the visual alarm.

💊 Which drugs WASTE potassium and which drugs SPARE it

🚿 K⁺ WASTING — “-ide” K⁺ draining Furosemide Hydrochlorothiazide Bumetanide → HYPOkalemia · needs a K⁺ supplement 🛑 K⁺ SPARING — S · S · P K⁺ held inside Spironolactone Sartans — losartan Prils — lisinopril → HYPERkalemia · NO K⁺ supplement, no salt subs
  • K⁺ WASTING diuretics end in -ide: furosemide, hydrochlorothiazide → the client loses potassium and often needs a supplement.
  • K⁺ SPARING drugs: Spironolactone · Sartans (losartan) · Prils (lisinopril) → the client keeps potassium. No potassium supplements and no salt substitutes with these.
🧠 “-IDE = it DIES (potassium leaves) · SSP = it STAYS Put.” Two letters and two initials sort every diuretic question you will ever see.

🚨 POTASSIUM IV — the four rules, in order

✅ THE ONLY SAFE WAY DILUTED KCl in IV fluid IV PUMP 1️⃣ HEART MONITOR 3️⃣ 10–20 mEq/hr MAX 4️⃣ Burning arm, patent line? → SLOW the rate 2️⃣ 🚫 NEVER IV PUSH KCl PUSH = DEATH Never push · never IM · never SubQ Never undiluted · never a bolus
1
FIRST ACTION = put the client on a HEART MONITOR.
2
NEVER IV push potassium = DEATH. Never IM, never SubQ, never undiluted.
3
ONLY 10–20 mEq/hr — on an IV pump, always diluted.
4
Client reports burning/discomfort and the line is patent → SLOW the infusion rate. “Stop the infusion” is the most commonly chosen distractor — about 48% of test takers pick it.

Also: confirm urine output ≥ 30 mL/hr before giving potassium · give oral KCl with food and a full glass of water · do not crush extended-release tablets · recheck the K⁺ level after replacement · check the magnesium if the K⁺ will not come up.

🧠 “Monitor · Never push · 10–20 · Slow it down.” Say those four out loud in order — that is the entire potassium infusion question.

🚨 EMERGENCY ORDER — potassium, both directions

📉 HYPOkalemia — replace safely

1
Cardiac monitor + assess respirations and bowel sounds.
2
Check urine output ≥ 30 mL/hr — no pee, no K⁺.
3
Oral KCl with food + potassium-rich foods (banana, avocado, potato, spinach, orange).
4
IV KCl — diluted, pump, 10–20 mEq/hr, monitored.
5
Replace the magnesium too, or the potassium will not stay up.

📈 HYPERkalemia — stabilize, shift, remove

1
IV CALCIUM GLUCONATE — protects the heart; does not lower the level.
2
Regular INSULIN + dextrose (D50) shifts K⁺ into cells; recheck the glucose.
3
Nebulized albuterol · sodium bicarbonate if acidotic — also temporary shifts.
4
Furosemide · sodium polystyrene sulfonate (Kayexalate) or another binder — actually removes it, over hours.
5
DIALYSIS — definitive. Stop all K⁺ sources and salt substitutes.
🧠 “C BIG K DROP” — Calcium · Bicarb · Insulin · Glucose · Kayexalate · Diuretic · Dialysis. Calcium is always first.
🧲

MAGNESIUM SULFATE

STEP 3 · MELLOWS THE MUSCLES · TEACH & MONITOR

One drug, four indications — and one set of numbers that tells you when to stop it.

🧪 Magnesium value scale

NORMAL 1.3 – 2.1 mEq/LCRITICAL <1.0 or >4.0
🧲 MAGNESIUM (Mg²⁺) units: mEq/L — some texts report mg/dL (about 1.6–2.6 mg/dL) 1.3–2.1 <1.0 CRIT LOW 1.0–1.2 HYPOmagnesemia 1.3–2.1 NORMAL 2.2–4.0 HYPERmagnesemia >4.0 CRIT HIGH The source card replaces magnesium when it falls below 1.5. Ranges & units vary by lab — always read the units.
🧠 “Small number, big drug.” Magnesium lives in the low ones — anything ≥ 3 is heading for toxicity.

💊 WHAT IT DOES — four indications

  • 1️⃣ Replace low magnesium — the source card uses below 1.5 KAPLAN
  • 2️⃣ Treatment for TORSADES DE POINTES NCLEX TIP — the twisting ventricular rhythm
  • 3️⃣ Preterm labor — “wild contractions.” Magnesium mellows the uterine muscle (tocolytic)
  • 4️⃣ Anticonvulsant — preeclampsia/eclampsia: it prevents and stops seizures

M = MELLOWS the muscles. Uterus, skeletal muscle, airway, heart — magnesium calms them all.

🧠 “Mag mellows the mother and the monitor.” It quiets contractions, quiets seizures and quiets Torsades.

📉 HYPOmagnesemia — below 1.3 · EXCITED

  • 🔨 HYPERreflexia (increased DTR), tremors, twitching, tetany, seizures
  • 🚽 Diarrhea, hyperactive bowel sounds
  • 🫀 TORSADES DE POINTES and V-fib, prolonged QT

Causes: alcoholism, malnourishment, Crohn's & celiac (malabsorption), chronic diarrhea, diuretics, long-term PPIs.

🧠 “No mag = no brakes.” Reflexes, bowels and the heart all rev up.

📈 HYPERmagnesemia — over 2.1 · SEDATED

  • 🔨 Decreased/absent DTRs — the earliest warning
  • 🫁 RESPIRATORY DEPRESSION, paralysis & weak muscles
  • 🚽 Hypoactive bowel sounds, constipation
  • 🫀 Heart block, bradycardia, hypotension → arrest
  • 🥵 Flushing, warmth, lethargy, slurred speech

Causes: renal failure, magnesium antacids/laxatives, and too much magnesium sulfate infusion.

🧠 “Too mellow to move, too mellow to breathe.” Reflexes go, then the respirations, then the heart.

🚨 WHEN DO YOU STOP THE MAGNESIUM INFUSION?

🛑 STOP THE INFUSION IF ANY ONE OF THESE IS TRUE 🫁 RESPIRATIONS RR < 12 🔨 REFLEXES no kick ❌ DECREASED DTRs 🚽 URINE OUTPUT kidneys are the only mag exit < 30 mL/hr
🚨 ANTIDOTE = IV CALCIUM GLUCONATE Keep it at the bedside for every magnesium sulfate infusion. Sequence: STOP the magnesium → give IV calcium gluconate → support airway & breathing → notify the provider.

Assess every hour on a mag drip: LOC → DTRs → respiratory rate → urine output → BP & cardiac rhythm → magnesium level.

👶 Possible findings in the NEWBORN of a client who received magnesium sulfate ATI

  • 🍼 Flaccid muscle tone (floppy, poor suck)
  • 🫁 Respiratory depression
  • ➕ Lethargy, hypotension, decreased reflexes — have neonatal resuscitation equipment ready at delivery
🧠 “12 · DTR · 30.” Three numbers, one drip: RR under 12, reflexes gone, urine under 30. Any one of them → stop and grab calcium gluconate.

🩺 EMERGENCY ORDER — magnesium, both directions

📉 HYPOmagnesemia / Torsades

1
Cardiac monitor + seizure precautions.
2
Torsades de Pointes → IV MAGNESIUM SULFATE. NCLEX TIP
3
Replace magnesium — IV on a pump for severe; oral for mild (expect diarrhea).
4
Check K⁺ and Ca²⁺ — they will not correct until the Mg does.
5
Re-assess DTRs & RR while infusing — you can overshoot into toxicity.

📈 HYPERmagnesemia / mag toxicity

1
🛑 STOP the magnesium — infusion, antacids, laxatives.
2
💉 IV CALCIUM GLUCONATE — the antidote, with cardiac monitoring.
3
Airway & breathing support — O₂, BVM, intubation equipment ready.
4
IV fluids + loop diuretic if renal function allows.
5
Dialysis for renal failure or a severe level.
🧠 “Mag for the twist, calcium for the too-much.” Torsades twists → give mag. Reflexes gone → give calcium.
⚡

QUICK RECALL

SAY IT OUT LOUD
⚡ Potassium IV1 monitor · 2 never push · 3 10–20 mEq/hr on a pump · 4 burning → slow it.
🛑 Mag stop signsRR < 12 · DTRs decreased · urine < 30 mL/hr → STOP + calcium gluconate.
🧲 Iron rulesBlack stool = normal · empty stomach 1 hr before meds · vit C helps, calcium blocks.
💉 B12 = lifelong shotNo intrinsic factor = no oral absorption. Sulfa drugs steal folic acid → supplement.

🧾 One-screen drug sheet

DrugIndicationWatch forTeach
Ferrous sulfate (oral)
Iron dextran (IV/IM)		Anemia r/t iron deficiencyBlack stools = expected, constipation, GI upset; Z-track & anaphylaxis risk with IM ironEmpty stomach 1 hr before meds · vitamin C / OJ boosts · calcium blocks · straw for liquid · “fresh fruits & whole grain bread”
Folic acidAnemia · prevents neural tube defectsSulfa drugs (sulfasalazine) block absorption; masks B12 anemia without fixing the neuro damageStart before pregnancy · leafy greens & fortified grains · take the prescribed dose
B12 cyanocobalaminPernicious anemia — no intrinsic factorNeuro signs: tingling, ataxia, memory loss; beefy red tongueLifelong IM/intranasal — oral will not absorb
Potassium (KCl)Hypokalemia below 3.5Never IV push · cardiac monitor · burning at site10–20 mEq/hr on a pump · oral with food & full glass of water · don't crush ER tabs
Magnesium sulfateLow Mg · Torsades · preterm labor · eclampsia seizuresRR < 12 · decreased DTRs · urine < 30 mL/hr · newborn: flaccid tone, respiratory depressionAntidote = calcium gluconate at the bedside; expect flushing & warmth
🎯 Cover & check — 9 rapid-fire questions
Q1: A client taking ferrous sulfate reports black stools. What do you do?
Nothing — reassure them. Dark or black stools are normal and expected with iron and are NOT a GI bleed.
Q2: What increases iron absorption and what blocks it?
Vitamin C / orange juice increases it. Calcium, dairy, antacids, coffee and tea block it. Take iron on an empty stomach 1 hour before other medications.
Q3: Which statement shows iron teaching was effective?
"I will eat more fresh fruits and whole grain bread." (HESI)
Q4: A client is started on sulfasalazine. Which vitamin will they need?
Folic acid — sulfa drugs decrease folic acid absorption, so a supplement is given while taking them.
Q5: Why can't a client with pernicious anemia take oral B12?
They lack intrinsic factor, which is required to absorb B12 in the ileum. Replacement must be lifelong IM (or intranasal).
Q6: What is the FIRST action before starting an IV potassium infusion?
Place the client on a cardiac/heart monitor. Also confirm urine output of at least 30 mL/hr.
Q7: The client's arm burns during a KCl infusion and the IV is patent. Best action?
Slow the infusion rate. Stopping the infusion is the most commonly chosen wrong answer (about 48%).
Q8: Name the three findings that make you STOP a magnesium sulfate infusion.
Respiratory rate below 12, decreased or absent deep tendon reflexes, and urine output under 30 mL/hr. Then give IV calcium gluconate — the antidote.
Q9: The monitor shows Torsades de Pointes. What is the drug?
IV magnesium sulfate. NCLEX TIP — low magnesium causes Torsades and magnesium treats it.