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Lesson 360 min read
Medical-Surgical Nursing
Electrolytes, Acid-Base Balance, Diabetes & Cardiac Care
Electrolyte Imbalances
| Electrolyte | Normal | Low (Signs) | High (Signs) |
|---|---|---|---|
| Sodium (Na+) | 135-145 mEq/L | Confusion, seizures, cramps | Thirst, dry mouth, restlessness |
| Potassium (K+) | 3.5-5.0 mEq/L | Weakness, leg cramps, arrhythmias | Tall T waves, muscle twitching |
| Calcium (Ca++) | 8.5-10.5 mg/dL | Tetany, Chvostek's, Trousseau's | Lethargy, kidney stones |
| Magnesium (Mg++) | 1.5-2.5 mEq/L | Tremors, tetany, seizures | Drowsiness, hypotension |
Chvostek's Sign
Tap facial nerve → facial twitching = hypocalcemia
Trousseau's Sign
BP cuff inflated → hand spasm (carpopedal) = hypocalcemia
Acid-Base Balance
ABG Normal Values
pH: 7.35-7.45PaCO2: 35-45 mmHgHCO3: 22-26 mEq/LPaO2: 80-100 mmHg
Respiratory Acidosis
pH ↓, CO2 ↑
Causes: COPD, respiratory depression
Respiratory Alkalosis
pH ↑, CO2 ↓
Causes: Hyperventilation, anxiety
Metabolic Acidosis
pH ↓, HCO3 ↓
Causes: DKA, renal failure, diarrhea
Metabolic Alkalosis
pH ↑, HCO3 ↑
Causes: Vomiting, NG suction
Diabetes Management
Hypoglycemia (<70 mg/dL)
TIRED Mnemonic:
- Tachycardia
- Irritability
- Restlessness
- Excessive hunger
- Diaphoresis (sweating)
15-15 Rule: Give 15g carbs, recheck in 15 min
Hyperglycemia (>180 mg/dL)
3 P's:
- Polyuria (frequent urination)
- Polydipsia (excessive thirst)
- Polyphagia (excessive hunger)
Treatment: Insulin, fluid replacement
DKA vs HHS
DKA (Type 1)
- Ketones present
- Kussmaul respirations
- Fruity breath odor
HHS (Type 2)
- No ketones
- Severe dehydration
- Very high glucose (>600)
Cardiac Conditions
MONA for MI (Chest Pain)
- M - Morphine (pain relief)
- O - Oxygen (if SpO2 <94%)
- N - Nitroglycerin (max 3 doses)
- A - Aspirin (chew 325mg)
Heart Failure - Left vs Right
Left: Pulmonary symptoms (dyspnea, crackles, pink frothy sputum)
Right: Peripheral symptoms (edema, JVD, hepatomegaly)
Heart Sounds
- S1: "Lub" - Mitral/Tricuspid close
- S2: "Dub" - Aortic/Pulmonic close
- S3: Heart failure (ventricular gallop)
- S4: Stiff ventricle (atrial gallop)