Medical Archive

C68 Electrolyte and Acid-Base Disorders

C68.1 Composition of Body Fluids

?? ??? turnover ??? ???? ???(?? ???) ??? ??
NH4+, ??? ?? ???? ?? ?? ?? ?
ECF??: ???? K+ (3.0~7.0), PO43+ ??. ??? ? ?? ??.

C68.2 Regulation of Osmolality and Volume

Bicarbonate buffer / protein (albumin, Hb) / Phosphate / bone

Handerson-Hasselbalch Equation
pH = 6.1 + …
Kidney? acid-base balance? ????? HCO3? NH4?? ? ?? ????.

??? ?? sampling? ??? ?? vein?? ??. (VBGA)? pH? 0.03 ?? PCO2? 6mmHg ??

C68.3 Sodium

C68.4 Potassium

C68.5 Magnesium

C68.6 Phosphorus

C68.7 Acid-Base Balance

C69 Maintenance and Replacement Therapy

Maintenance therapy

Na	3 mEq/kg/day
K	2 mEq/kg/day
Glucose	4 g/kg/day

Maintenance water

BODY WEIGHTFLUID PER DAY
0-10 kg	100 mL/kg
11-20 kg	1,000 mL + 50 mL/kg for each kg >10 kg
>20 kg	1,500 mL + 20 mL/kg for each kg >20 kg*

For body weight 0-10 kg: 4 mL/kg/hr
For body weight 10-20 kg: 40 mL/hr + 2 mL/kg/hr × (wt – 10 kg)
For body weight >20 kg: 60 mL/hr + 1 mL/kg/hr × (wt – 20 kg)*
*The maximum fluid rate is normally 100 mL/hr.

Intravenous solutions

Glucose

Variations in Maintenance Water and Electrolytes

Replacement Fluids

C70 Deficit Therapy

Clinical manifestations

BP??? ???.
??? ??, Skin turgot? ??
???? ???! ?? ????.
??? ? ???… ?? ??? ??.

Laboratory findings

??? (Na >150): ??? ??? (doughy), ??, ?? ?? ?? ?? ??
??? (Na <130): ??? ????, ????/??, ?? ?? ??

Calculation of the Fluid Deficit

? 24hr? ??? ???+?? ??? ??? ???? ??
????? 1:2?, ???? 1:4? ?? ?.

?? ??? ?: ??% x 10 x ?? ?? kg (?? ?? ?? x 1,000mL)

Approach to Severe Dehydration

Phase 1 – ????? ??, ???? ??
0.9% NS (or RL) 20mL/kg over 1hr
Alkalosis: RL, 5DS? ???? ? ???? x
Acidosis: ??? bicarbonate ? ?? ?? ?.

DS? initial fluid resuscitation? ??? ??. maintainance fluid??.

Phase 2 – ECF? ?-?? ??? ??? ??
D5 half NS, ??? ??? over 23h
D5 NS if SIADH, hypovolemic, hyponatremic
Hypotonic: ? 8??? ? ?? ??? 16??? ?? ?
Hypertonic: 2??? ?? ? ??? (???? ?? ??)
20mEq/L KCl – ?????? over 1-2 day

Phase 3 – ?? K+? ??
Following 1-2 days
Same as maintenance (D5 half NS), 125mL/kg/day

Monitoring and Adjusting Therapy

??: 50mL/kg ?? ??
???: 100mL/kg ?? ??
??: 20?-1?? ?? 10-20mL/kg IV -> ?? ???? ?? ?????

Hyponatremic Dehydration

Hypernatremic Dehydration

C71 Fluid and Electrolyte Treatment of Specific Disorders

Acute Diarrhea

See Chapter 366 .

Pyloric Stenosis

See Chapter 355.1 .

Perioperative Fluids

See Chapter 74 .