TONICITY OF INTRAVENOUS FLUIDS
Solution Tonicity
0.4% saline (1/2 NS) Hypotonic
0.9% saline (NS) Isotonic
5% dextrose in water (5% D/W) Isotonic
5% dextrose in 0.225% saline (5% D ¼ NS) Isotonic
Lactated Ringer’s solution Isotonic
5% dextrose in lactated Ringer’s sol’n Hypertonic
5% dextrose in lactated Ringer’s sol’n Hypertonic
5% dextrose in 0.45% saline (5% D/1/2 NS) Hype
10% dextrose in water (10% D/W) Hypertonic
DAILY BODY FLUID EXCRETION
Kidneys 1500 ml
Skin by diffusion 400 ml
Lungs 350 ml
Feces 150 ml
Skin by perspiration 100 ml
ELECTROLYTES NORMAL VALUES
Sodium 135 – 145 mEq/L
Potassium 3.5 – 5.1 mEq/L
Calcium 8.6 – 10.0 mEq/L
Magnesium 1.6 – 2.6 mEq/L
Phosphorus 2.7 – 4.5 mg/dL
ELECTROCARDIOGRAPHIC CHANGES IN ELECTROLYTE IMBALANCE
Electrolyte ECG Changes
Imbalance
Hypocalcemia Prolonged ST Interval
Prolonged QT interval
Hypercalcemia Shortened ST segment
Widened T wave
Hypokalemia ST depression
Shallow, flat, or
inverted T wave
Prominent U wave
Hyperkalemia Tall peaked T waves
Flat P waves
Widened QRS complex
Prolonged PR interval
Hypomagnesemia Depressed ST segment
Prolonged PR interval
Widened QRS complex
Hypermagnesemia Prolonged PR interval
Widened QRS 