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 Hyperkalemia PEAKED T waves
wave, weakness, constipation
V-Fib cardiac arrest
Calcium (Ca2+) 9–10.5 mg/dL Hypocalcemia Hypercalcemia weakness,
Chvostek+, Trousseau+, constipation, bradycardia
tetany, seizures
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 = subtherapeutic CLOT risk > 3 = supratherapeutic
2–3 BLEEDING risk
aPTT (heparin) Normal 30–40 sec | Subtherapeutic clot still forming > 70 sec notify provider
Therapeutic: reduce infusion
1.5–2.5× = ~45–70 sec
CARDIAC
Troponin I (TI) 0–0.1 ng/mL | Onset: 4–6 hr | — ELEVATED = MI (most
Peak: 12–24 hr specific cardiac marker)
BNP < 100 = No HF | 100–300 = HF — Higher = more ventricular
present | > 600 = moderate | stretch/fluid overload
> 900
= severe
ABGs pH 7.35–7.45 | PCO2 35–45 | pH<7.35=ACIDOSIS | pH>7.45=ALKALOSIS |
HCO3- 22–28 | SaO2 95–100% PCO2>45=Resp PCO2<35=Resp alk |
acid | HCO3<22=Met acid 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, Excessive IV fluids, kidney failure, heart failure,
Causes NPO, diuretics, fever, ileostomy/fistula, GI suction SIADH, long-term corticosteroids, water
intoxication
Key Signs HR (thready), BP, dry mucous membranes, poor skin BOUNDING pulse, HR, BP, distended neck veins (JVD),
turgor, 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, Fluid & sodium restriction, diuretics (furosemide),
UO HOB up, O2, daily weights, crackle assessment
30 mL/hr, mental status, fluids in vs out
Treatment Mild: oral fluids | Severe: IV 0.9% NS | Correct underlying Furosemide (Lasix), fluid/Na+ restriction,
cause 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 Dehydration, fever, Cushing syndrome,
disease, excessive water intake, hyperglycemia corticosteroids, 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, AGITATION, confusion, INTENSE THIRST
SEIZURES, muscle weakness, DTRs, N/D/cramps (hallmark!), muscle twitching, weakness, DTRs
CV With hypovolemia: weak pulse, BP | With HR and BP vary by volume status
hypervolemia: bounding pulse, BP
Treatment Mild-moderate: 0.9% NS | SEVERE: 3% hypertonic saline 0.9% NS or D5½NS (hypotonic) or PO if alert |
(CRITICAL RESCUE — monitor closely for Diuretics | Na+ restriction | CORRECT SLOWLY —
overcorrection!) Reduce offending drug | Correct rapid correction causes cerebral edema
SLOWLY
■ 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,
13.6/13.7) drainage, NG suction, alkalosis, insulin, albuterol, TPN, acidosis, crush injury, salt substitutes, blood
black licorice, adrenal issues transfusion, excessive K+ 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, Bradycardia, hypotension, paresthesias (hands/feet)
confusion
Respiratory SHALLOW RESPIRATIONS (diaphragm is a muscle — Respiratory muscle weakness
weakness!)
GI peristalsis, hypoactive BS, N/V, CONSTIPATION, GI motility, DIARRHEA, cramping
distension
Musculoskeletal Muscle weakness, leg cramps, too weak to stand, DTRs Muscle weakness, DTRs, paresthesias
Treatment O2 FIRST (respiratory!); oral K+ (preferred); IV K+ if STOP K+ inputs; cardiac monitoring; glucose + insulin
severe (DILUTED, 5–10 mEq/hr); K+-rich diet; cardiac (shifts K+ into cells); Ca2+ gluconate IV (protects
monitoring 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 Hyperkalemia PEAKED T waves
wave, weakness, constipation
V-Fib cardiac arrest
Calcium (Ca2+) 9–10.5 mg/dL Hypocalcemia Hypercalcemia weakness,
Chvostek+, Trousseau+, constipation, bradycardia
tetany, seizures
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 = subtherapeutic CLOT risk > 3 = supratherapeutic
2–3 BLEEDING risk
aPTT (heparin) Normal 30–40 sec | Subtherapeutic clot still forming > 70 sec notify provider
Therapeutic: reduce infusion
1.5–2.5× = ~45–70 sec
CARDIAC
Troponin I (TI) 0–0.1 ng/mL | Onset: 4–6 hr | — ELEVATED = MI (most
Peak: 12–24 hr specific cardiac marker)
BNP < 100 = No HF | 100–300 = HF — Higher = more ventricular
present | > 600 = moderate | stretch/fluid overload
> 900
= severe
ABGs pH 7.35–7.45 | PCO2 35–45 | pH<7.35=ACIDOSIS | pH>7.45=ALKALOSIS |
HCO3- 22–28 | SaO2 95–100% PCO2>45=Resp PCO2<35=Resp alk |
acid | HCO3<22=Met acid 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, Excessive IV fluids, kidney failure, heart failure,
Causes NPO, diuretics, fever, ileostomy/fistula, GI suction SIADH, long-term corticosteroids, water
intoxication
Key Signs HR (thready), BP, dry mucous membranes, poor skin BOUNDING pulse, HR, BP, distended neck veins (JVD),
turgor, 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, Fluid & sodium restriction, diuretics (furosemide),
UO HOB up, O2, daily weights, crackle assessment
30 mL/hr, mental status, fluids in vs out
Treatment Mild: oral fluids | Severe: IV 0.9% NS | Correct underlying Furosemide (Lasix), fluid/Na+ restriction,
cause 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 Dehydration, fever, Cushing syndrome,
disease, excessive water intake, hyperglycemia corticosteroids, 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, AGITATION, confusion, INTENSE THIRST
SEIZURES, muscle weakness, DTRs, N/D/cramps (hallmark!), muscle twitching, weakness, DTRs
CV With hypovolemia: weak pulse, BP | With HR and BP vary by volume status
hypervolemia: bounding pulse, BP
Treatment Mild-moderate: 0.9% NS | SEVERE: 3% hypertonic saline 0.9% NS or D5½NS (hypotonic) or PO if alert |
(CRITICAL RESCUE — monitor closely for Diuretics | Na+ restriction | CORRECT SLOWLY —
overcorrection!) Reduce offending drug | Correct rapid correction causes cerebral edema
SLOWLY
■ 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,
13.6/13.7) drainage, NG suction, alkalosis, insulin, albuterol, TPN, acidosis, crush injury, salt substitutes, blood
black licorice, adrenal issues transfusion, excessive K+ 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, Bradycardia, hypotension, paresthesias (hands/feet)
confusion
Respiratory SHALLOW RESPIRATIONS (diaphragm is a muscle — Respiratory muscle weakness
weakness!)
GI peristalsis, hypoactive BS, N/V, CONSTIPATION, GI motility, DIARRHEA, cramping
distension
Musculoskeletal Muscle weakness, leg cramps, too weak to stand, DTRs Muscle weakness, DTRs, paresthesias
Treatment O2 FIRST (respiratory!); oral K+ (preferred); IV K+ if STOP K+ inputs; cardiac monitoring; glucose + insulin
severe (DILUTED, 5–10 mEq/hr); K+-rich diet; cardiac (shifts K+ into cells); Ca2+ gluconate IV (protects
monitoring 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.
