NUR 242 EXAM 2 — HIGH-YIELD STUDY GUIDE
Unit 3: Fluids/Electrolytes/Acid-Base | Units 4/5: Cardiovascular | Unit 6: Urinary/Renal | Unit 7: GI | Includes Patient Teaching · Adverse
Effects · Contraindications
■ HOW TO USE THIS GUIDE: Blue boxes = patient teaching (EXAM FAVORITE). Orange boxes = drug alerts/adverse effects. Red boxes =
nursing safety emergencies. ALL lab values are GALEN values.
■ GALEN LAB VALUES — USE THESE ONLY (From Your School's Standardized Reference)
ELECTROLYTES Normal (Galen) Low = ? High = ?
Sodium (Na+) 135–145 mEq/L Hyponatremia → confusion, seizures Hypernatremia → agitation, thirst,
brain shrinks
Potassium (K+) 3.5–5.0 mEq/L Hypokalemia → ST depression, U wave, Hyperkalemia → PEAKED T waves →
weakness, constipation V-Fib → cardiac arrest
Calcium (Ca2+) 9–10.5 mg/dL Hypocalcemia → Chvostek+, Hypercalcemia → weakness,
Trousseau+, tetany, seizures constipation, bradycardia
Magnesium (Mg2+) 1.5–2.5 mEq/L Hypomagnesemia → Chvostek+, Hypermagnesemia → ABSENT DTRs
Trousseau+, dysrhythmias → respiratory arrest
COAGULATION
INR (warfarin) Normal 0.9–1.2 | Therapeutic: 2–3 <2 = subtherapeutic → CLOT risk > 3 = supratherapeutic → BLEEDING
risk
aPTT (heparin) Normal 30–40 sec | Therapeutic: Subtherapeutic → clot still forming > 70 sec → notify provider → reduce
1.5–2.5× = ~45–70 sec infusion
CARDIAC
Troponin I (TI) 0–0.1 ng/mL | Onset: 4–6 hr | — ELEVATED = MI (most specific
Peak: 12–24 hr cardiac marker)
BNP < 100 = No HF | 100–300 = HF — Higher = more ventricular stretch/fluid
present | > 600 = moderate | > 900 overload
= severe
ABGs pH 7.35–7.45 | PCO2 35–45 | pH<7.35=ACIDOSIS | PCO2>45=Resp pH>7.45=ALKALOSIS |
HCO3- 22–28 | SaO2 95–100% acid | HCO3<22=Met acid PCO2<35=Resp alk | HCO3>28=Met
alk
BUN / Creatinine BUN 10–20 | Cr: Male 0.6–1.2 / — Elevated = kidney dysfunction
Female 0.5–1.1 mg/dL
GFR 90–120 mL/min < 60 = CKD | < 15 = kidney failure —
OTHER
Digoxin (therapeutic) 0.5–2 ng/mL Subtherapeutic > 2 ng/mL = TOXICITY →
bradycardia, N/V, yellow-green vision
Adult VS HR 60–100 | BP <120/80 | RR — HTN crisis ≥180/120 + symptoms =
12–20 | Temp 97.6–99.5°F EMERGENCY
UNIT 3 — FLUIDS, ELECTROLYTES & ACID-BASE (Ch 13–14)
DEHYDRATION vs FLUID OVERLOAD
Feature DEHYDRATION (not enough fluid) FLUID OVERLOAD (too much fluid)
BOX 13.1 Hemorrhage, vomiting, diarrhea, diaphoresis, burns, NPO, Excessive IV fluids, kidney failure, heart failure, SIADH,
Causes diuretics, fever, ileostomy/fistula, GI suction long-term corticosteroids, water intoxication
Key Signs ↑HR (thready), ↓BP, dry mucous membranes, poor skin turgor, BOUNDING pulse, ↑HR, ↑BP, distended neck veins (JVD),
dark urine, ↓UO, sudden WEIGHT LOSS, confusion pitting edema, moist CRACKLES, SOB, weight GAIN
, Feature DEHYDRATION (not enough fluid) FLUID OVERLOAD (too much fluid)
Priority Nursing Daily weights (same time/scale = MOST RELIABLE), VS, UO Fluid & sodium restriction, diuretics (furosemide), HOB up,
≥30 mL/hr, mental status, fluids in vs out O2, daily weights, crackle assessment
Treatment Mild: oral fluids | Severe: IV 0.9% NS | Correct underlying cause Furosemide (Lasix), fluid/Na+ restriction, position HOB
elevated 30–45°
■ Older adults: skin turgor LESS reliable — assess oral mucosa, behavior, and eyes instead
SODIUM IMBALANCES — Sodium = Brain! Where Na+ goes, water follows.
HYPONATREMIA Na+ < 135 HYPERNATREMIA Na+ > 145
Causes GI fluid loss, diuretics, burns, SIADH, HF, kidney disease, Dehydration, fever, Cushing syndrome, corticosteroids,
excessive water intake, hyperglycemia excessive Na+ intake, hyperventilation, infection,
diaphoresis
Brain Effect Water shifts INTO brain → brain SWELLS → ↑ICP Water shifts OUT of brain → brain SHRINKS → cell
dehydration
Key S&S; CONFUSION (older adults: #1 sign!), lethargy, SEIZURES, AGITATION, confusion, INTENSE THIRST (hallmark!),
muscle weakness, ↓DTRs, N/D/cramps muscle twitching, weakness, ↓DTRs
CV With hypovolemia: weak pulse, ↓BP | With hypervolemia: HR and BP vary by volume status
bounding pulse, ↑BP
Treatment Mild-moderate: 0.9% NS | SEVERE: 3% hypertonic saline 0.9% NS or D5½NS (hypotonic) or PO if alert | Diuretics |
(CRITICAL RESCUE — monitor closely for overcorrection!) Na+ restriction | CORRECT SLOWLY — rapid correction
Reduce offending drug | Correct SLOWLY causes cerebral edema
■ PATIENT TEACHING — SODIUM
✔ HYPONATREMIA: Report sudden confusion IMMEDIATELY — especially if older adult — low Na+ is a common hidden cause
✔ HYPONATREMIA: Do NOT drink excessive plain water to "flush out" illness — this worsens dilutional hyponatremia
✔ HYPERNATREMIA: Drink adequate water daily; thirst means Na+ is already rising
✔ HYPERNATREMIA: Reduce salt in diet — avoid processed food, canned soups, fast food (all very high in sodium)
✔ BOTH: NEVER adjust IV fluid rate yourself; report confusion, muscle weakness, or seizures IMMEDIATELY
POTASSIUM IMBALANCES — K+ = Heart! Controls cell excitability and cardiac rhythm.
■ GALEN: Potassium (K+) 3.5–5.0 mEq/L
HYPOKALEMIA K+ < 3.5 HYPERKALEMIA K+ > 5.0
Causes (BOX DIURETICS (#1!), corticosteroids, diarrhea/vomiting, GI Kidney failure, ACEi/ARBs, K+-sparing diuretics, acidosis,
13.6/13.7) drainage, NG suction, alkalosis, insulin, albuterol, TPN, black crush injury, salt substitutes, blood transfusion, excessive K+
licorice, adrenal issues intake, uncontrolled DM
ECG (Fig 13.10) ST DEPRESSION, FLAT/INVERTED T waves, U WAVE TALL PEAKED T WAVES → widened QRS → V-Fib →
appears after T CARDIAC ARREST
CV/Neuro Irregular heartbeat, thready pulse, ↓BP, anxiety, confusion Bradycardia, hypotension, paresthesias (hands/feet)
Respiratory SHALLOW RESPIRATIONS (diaphragm is a muscle — Respiratory muscle weakness
weakness!)
GI ↓ peristalsis, hypoactive BS, N/V, CONSTIPATION, distension ↑ GI motility, DIARRHEA, cramping
Musculoskeletal Muscle weakness, leg cramps, too weak to stand, ↓DTRs Muscle weakness, ↓DTRs, paresthesias
Treatment O2 FIRST (respiratory!); oral K+ (preferred); IV K+ if severe STOP K+ inputs; cardiac monitoring; glucose + insulin (shifts
(DILUTED, 5–10 mEq/hr); K+-rich diet; cardiac monitoring K+ into cells); Ca2+ gluconate IV (protects heart); dialysis
(kidney failure)
■ NURSING SAFETY — Drug Alert — IV POTASSIUM (p.264)
NEVER give K+ by IV PUSH → CARDIAC ARREST. NEVER give IM or SQ → tissue necrosis. Must be DILUTED. Rate: 5–10 mEq/hr maximum.
CONFIRM UO ≥30 mL/hr before giving IV K+. Per Joint Commission NPSG: concentrated K+ must be prepared by pharmacist ONLY — NEVER
stored in patient care areas.
Unit 3: Fluids/Electrolytes/Acid-Base | Units 4/5: Cardiovascular | Unit 6: Urinary/Renal | Unit 7: GI | Includes Patient Teaching · Adverse
Effects · Contraindications
■ HOW TO USE THIS GUIDE: Blue boxes = patient teaching (EXAM FAVORITE). Orange boxes = drug alerts/adverse effects. Red boxes =
nursing safety emergencies. ALL lab values are GALEN values.
■ GALEN LAB VALUES — USE THESE ONLY (From Your School's Standardized Reference)
ELECTROLYTES Normal (Galen) Low = ? High = ?
Sodium (Na+) 135–145 mEq/L Hyponatremia → confusion, seizures Hypernatremia → agitation, thirst,
brain shrinks
Potassium (K+) 3.5–5.0 mEq/L Hypokalemia → ST depression, U wave, Hyperkalemia → PEAKED T waves →
weakness, constipation V-Fib → cardiac arrest
Calcium (Ca2+) 9–10.5 mg/dL Hypocalcemia → Chvostek+, Hypercalcemia → weakness,
Trousseau+, tetany, seizures constipation, bradycardia
Magnesium (Mg2+) 1.5–2.5 mEq/L Hypomagnesemia → Chvostek+, Hypermagnesemia → ABSENT DTRs
Trousseau+, dysrhythmias → respiratory arrest
COAGULATION
INR (warfarin) Normal 0.9–1.2 | Therapeutic: 2–3 <2 = subtherapeutic → CLOT risk > 3 = supratherapeutic → BLEEDING
risk
aPTT (heparin) Normal 30–40 sec | Therapeutic: Subtherapeutic → clot still forming > 70 sec → notify provider → reduce
1.5–2.5× = ~45–70 sec infusion
CARDIAC
Troponin I (TI) 0–0.1 ng/mL | Onset: 4–6 hr | — ELEVATED = MI (most specific
Peak: 12–24 hr cardiac marker)
BNP < 100 = No HF | 100–300 = HF — Higher = more ventricular stretch/fluid
present | > 600 = moderate | > 900 overload
= severe
ABGs pH 7.35–7.45 | PCO2 35–45 | pH<7.35=ACIDOSIS | PCO2>45=Resp pH>7.45=ALKALOSIS |
HCO3- 22–28 | SaO2 95–100% acid | HCO3<22=Met acid PCO2<35=Resp alk | HCO3>28=Met
alk
BUN / Creatinine BUN 10–20 | Cr: Male 0.6–1.2 / — Elevated = kidney dysfunction
Female 0.5–1.1 mg/dL
GFR 90–120 mL/min < 60 = CKD | < 15 = kidney failure —
OTHER
Digoxin (therapeutic) 0.5–2 ng/mL Subtherapeutic > 2 ng/mL = TOXICITY →
bradycardia, N/V, yellow-green vision
Adult VS HR 60–100 | BP <120/80 | RR — HTN crisis ≥180/120 + symptoms =
12–20 | Temp 97.6–99.5°F EMERGENCY
UNIT 3 — FLUIDS, ELECTROLYTES & ACID-BASE (Ch 13–14)
DEHYDRATION vs FLUID OVERLOAD
Feature DEHYDRATION (not enough fluid) FLUID OVERLOAD (too much fluid)
BOX 13.1 Hemorrhage, vomiting, diarrhea, diaphoresis, burns, NPO, Excessive IV fluids, kidney failure, heart failure, SIADH,
Causes diuretics, fever, ileostomy/fistula, GI suction long-term corticosteroids, water intoxication
Key Signs ↑HR (thready), ↓BP, dry mucous membranes, poor skin turgor, BOUNDING pulse, ↑HR, ↑BP, distended neck veins (JVD),
dark urine, ↓UO, sudden WEIGHT LOSS, confusion pitting edema, moist CRACKLES, SOB, weight GAIN
, Feature DEHYDRATION (not enough fluid) FLUID OVERLOAD (too much fluid)
Priority Nursing Daily weights (same time/scale = MOST RELIABLE), VS, UO Fluid & sodium restriction, diuretics (furosemide), HOB up,
≥30 mL/hr, mental status, fluids in vs out O2, daily weights, crackle assessment
Treatment Mild: oral fluids | Severe: IV 0.9% NS | Correct underlying cause Furosemide (Lasix), fluid/Na+ restriction, position HOB
elevated 30–45°
■ Older adults: skin turgor LESS reliable — assess oral mucosa, behavior, and eyes instead
SODIUM IMBALANCES — Sodium = Brain! Where Na+ goes, water follows.
HYPONATREMIA Na+ < 135 HYPERNATREMIA Na+ > 145
Causes GI fluid loss, diuretics, burns, SIADH, HF, kidney disease, Dehydration, fever, Cushing syndrome, corticosteroids,
excessive water intake, hyperglycemia excessive Na+ intake, hyperventilation, infection,
diaphoresis
Brain Effect Water shifts INTO brain → brain SWELLS → ↑ICP Water shifts OUT of brain → brain SHRINKS → cell
dehydration
Key S&S; CONFUSION (older adults: #1 sign!), lethargy, SEIZURES, AGITATION, confusion, INTENSE THIRST (hallmark!),
muscle weakness, ↓DTRs, N/D/cramps muscle twitching, weakness, ↓DTRs
CV With hypovolemia: weak pulse, ↓BP | With hypervolemia: HR and BP vary by volume status
bounding pulse, ↑BP
Treatment Mild-moderate: 0.9% NS | SEVERE: 3% hypertonic saline 0.9% NS or D5½NS (hypotonic) or PO if alert | Diuretics |
(CRITICAL RESCUE — monitor closely for overcorrection!) Na+ restriction | CORRECT SLOWLY — rapid correction
Reduce offending drug | Correct SLOWLY causes cerebral edema
■ PATIENT TEACHING — SODIUM
✔ HYPONATREMIA: Report sudden confusion IMMEDIATELY — especially if older adult — low Na+ is a common hidden cause
✔ HYPONATREMIA: Do NOT drink excessive plain water to "flush out" illness — this worsens dilutional hyponatremia
✔ HYPERNATREMIA: Drink adequate water daily; thirst means Na+ is already rising
✔ HYPERNATREMIA: Reduce salt in diet — avoid processed food, canned soups, fast food (all very high in sodium)
✔ BOTH: NEVER adjust IV fluid rate yourself; report confusion, muscle weakness, or seizures IMMEDIATELY
POTASSIUM IMBALANCES — K+ = Heart! Controls cell excitability and cardiac rhythm.
■ GALEN: Potassium (K+) 3.5–5.0 mEq/L
HYPOKALEMIA K+ < 3.5 HYPERKALEMIA K+ > 5.0
Causes (BOX DIURETICS (#1!), corticosteroids, diarrhea/vomiting, GI Kidney failure, ACEi/ARBs, K+-sparing diuretics, acidosis,
13.6/13.7) drainage, NG suction, alkalosis, insulin, albuterol, TPN, black crush injury, salt substitutes, blood transfusion, excessive K+
licorice, adrenal issues intake, uncontrolled DM
ECG (Fig 13.10) ST DEPRESSION, FLAT/INVERTED T waves, U WAVE TALL PEAKED T WAVES → widened QRS → V-Fib →
appears after T CARDIAC ARREST
CV/Neuro Irregular heartbeat, thready pulse, ↓BP, anxiety, confusion Bradycardia, hypotension, paresthesias (hands/feet)
Respiratory SHALLOW RESPIRATIONS (diaphragm is a muscle — Respiratory muscle weakness
weakness!)
GI ↓ peristalsis, hypoactive BS, N/V, CONSTIPATION, distension ↑ GI motility, DIARRHEA, cramping
Musculoskeletal Muscle weakness, leg cramps, too weak to stand, ↓DTRs Muscle weakness, ↓DTRs, paresthesias
Treatment O2 FIRST (respiratory!); oral K+ (preferred); IV K+ if severe STOP K+ inputs; cardiac monitoring; glucose + insulin (shifts
(DILUTED, 5–10 mEq/hr); K+-rich diet; cardiac monitoring K+ into cells); Ca2+ gluconate IV (protects heart); dialysis
(kidney failure)
■ NURSING SAFETY — Drug Alert — IV POTASSIUM (p.264)
NEVER give K+ by IV PUSH → CARDIAC ARREST. NEVER give IM or SQ → tissue necrosis. Must be DILUTED. Rate: 5–10 mEq/hr maximum.
CONFIRM UO ≥30 mL/hr before giving IV K+. Per Joint Commission NPSG: concentrated K+ must be prepared by pharmacist ONLY — NEVER
stored in patient care areas.
