1. Fluid & Electrolytes Management: Part I
Component & composition of body
fluid
Mechanisms of fluid homeostasis
Parenteral fluid therapy

2. Body Fluid Compartments:
ICF:
55%~75%
2/3
X 50~70%
lean body weight
TBW
Extravascular
Interstitial
fluid
3/4
Male (60%) > female (50%)
Most concentrated in skeletal muscle
TBW=0.6xBW
ICF=0.4xBW
ECF=0.2xBW
1/3
ECF
Intravascular
plasma
1/4

3. Composition of Body Fluids:
Ca 2+
Mg 2+ K+
Na+
Cl-
PO43-
Organic
anion
HCO3-
Protein 50
100
150
Cations
Anions
ECF
ICF
Osmolarity = solute/(solute+solvent)
Osmolality = solute/solvent (290~310mOsm/L)
Tonicity = effective osmolality
Plasma osmolility = 2 x (Na) + (Glucose/18) + (Urea/2.8)
Plasma tonicity = 2 x (Na) + (Glucose/18)

4. Regulation of Fluids: Hydrostatic pressure v.s. Oncotic pressure
 Albumin is the major determining oncotic pressure

5. Regulation of Fluids: Renal sympathetic nerves Renin-angiotensin-
aldosterone system
Atrial natriuretic peptide (ANP)

6. Composition of GI Secretions:
Source
Volume (ml/24h)
Na+* K+
Cl-
HCO3-
Salivary
1500 (500~2000)
10 (2~10)
26 (20~30)
10 (8~18) 30
Stomach
1500 (100~4000)
60 (9~116)
10 (0~32)
130 (8~154)
Duodenum
100~2000
140 5 80
Ileum
3000
140 (80~150)
5 (2~8)
104 (43~137)
Colon 60 40
Pancreas
140 (113~185)
5 (3~7)
75 (54~95)
115
Bile
50-800
145 (131~164)
5 (3~12)
100 (89~180) 35
* Average concentration: mmol/L

7. Signs of Hypovolemia: Diminished skin turgor Dry oral mucus membrane
Oliguria
- <500ml/day
- normal: 0.5~1ml/kg/h
Tachycardia
Hypotension
Hypoperfusioncyanosis
Altered mental status

8. Clinical Diagnosis of Hypovolemia:
Thorough history taking: poor intake, GI
bleeding…etc
BUN : Creatinine > 20 : 1
- BUN↑: hyperalimentation, glucocorticoid
therapy, UGI bleeding
Increased specific gravity
Increased hematocrit
Electrolytes imbalance
Acid-base disorder

9. Parenteral Fluid Therapy:
Crystalloids:
- contain Na as the main osmotically
active particle
- useful for volume expansion (mainly
interstitial space)
- for maintenance infusion
- correction of electrolyte abnormality

10. Crystalloids: Isotonic crystalloids - Lactated Ringer’s, 0.9% NaCl
- only 25% remain intravascularly
Hypertonic saline solutions
- 3% NaCl
Hypotonic solutions
- D5W, 0.45% NaCl
- less than 10% remain intra-
vascularly, inadequate for fluid
resuscitation

11. Colloid Solutions: Contain high molecular weight
substancesdo not readily migrate across
capillary walls
Preparations
- Albumin: 5%, 25%
- Dextran
- Gelifundol
- Haes-steril 10%

12. Common parenteral fluid therapy
Solutions
Volumes
Na+ K+
Ca2+
Mg2+
Cl-
HCO3-
Dextrose
mOsm/L
ECF
142 4 5
103 27
Lactated Ringer’s
130 3
109 28
273
0.9% NaCl
154
308
0.45% NaCl 77
D5W
D5/0.45% NaCl 50
406
3% NaCl
513
1026
6% Hetastarch
500
310
5% Albumin
250,500
<2.5
330
25% Albumin
20,50,100

13. The Influence of Colloid & Crystalloid on Blood Volume:
Infusion
volume
200
600
1000
1000cc
Lactated Ringers
500cc
5% Albumin
500cc
6% Hetastarch
500cc
Whole blood

14. Signs of Hypervolemia:
Hypertension
Polyuria
Peripheral edema
Wet lung
Jugular vein engorgement
Especially when hypo-albuminemia

15. Management of Hypervolemia:
Prevention is the best way
Guide fluid therapy with CVP level or
pulmonary wedge pressure
Diuretics
Increase oncotic pressure: FFP or
albumin infusion (may followed by diuretics)
Dialysis

16. Fluid Management: Goal: - to maintain urine output of 0.5~1.0mg/kg/h
Rule:
100* *10 +〔 (x-20)/10 〕*20
= x
Electrolytes require:
- Na+: 1-2mmol/kg/day
- K+: 0.5~1.0mmol/kg/day
Avoid fluid overload, especially in malnutrition,
heart failure and renal insufficiency patient

17. Fluid Management: For acute blood loss
- Begin with 2-3L isotonic crystalloid to
restore blood pressure and peripheral
perfusion
- Early use of colloid
- Crystalloid + 5% albumin in a ratio of 4:1
- Blood transfusion
- Large borne IV line

18. To be Continued !!!