11. • Loss of isotonic fluid
that might be due to
hemorrhage (neglect
loss of intracellular fluid
as RBC volume),
isotonic urine, or the
immediate
consequence of
diarrhea or vomiting:
12. • Loss of hypotonic fluid
that might be due to
sweating (dehydration),
hypotonic urine, or
diabetes insipidus:
19. A 23-year-old man is brought to the Emergency
Department after collapsing during basketball
practice. On admission he is lethargic and appears
confused. His coach reports that it was hot in the
gym and he was drinking a lot of water during
practice. An increase in which of the following is
the most likely cause of his symptoms?
a. Intracellular tonicity
b. Extracellular tonicity
c. Intracellular volume
d. Extracellular volume
e. Plasma volume
20. A 70kg man is given a treatment intravenously. The diagram shows the
intracellular(ICF) volume And extracellular fluid(ECF)volume before and
after treatment. Which of the following treatments was likely
administered to this man?
A. Hypertonic saline
B. Hypotonic saline.
C. Isotonic saline
D. Isotonic glucose.
21. 7.A 14-year-old boy has a craniotomy performed under general endotracheal
anesthesia for removal of a craniopharyngioma. The anesthetic agent used is
halothane, and when he is fully awake in the recovery room, he is extubated and
sent to the floor. Five percent dextrose in one-third normal saline was dripping in his
intra-venous line at a rate of 125 mL/h. Four hours later, the nurses report that he
cannot be roused from a deep sleep. They also point out that his urinary output in
each of those 4 hours was 1059, 1100, 980, and 1250
mL, respectively. Laboratory studies show:
Sodium 156 mEq/L
Osmolarity 312 mOsm/L
pH 7.55
pco2 28 mm Hg
Bicarbonate 24 mEq/L
Which of the following best explains these findings?
(A) Brain edema
(B) Nephrogenic diabetes insipidus
(C) Respiratory depression induced by unmetabolized anesthetic
(D) Surgical trauma to the posterior pituitary
(E) Water retention
22. Oral Rehydration Therapy Is Driven by Solute
Transport
Oral administration of rehydration solutions has dramatically
reduced the mortality resulting from cholera and other diseases that
involve excessive losses of water and solutes from the
gastrointestinal tract. The main ingredients of rehydration solutions
are glucose, NaCl, and water. The glucose and Na+ ions are
reabsorbed by SGLT1 and other transporters in the epithelial cells
lining the lumen of the small intestine .
Deposition of these solutes on the basolateral side of the epithelial
cells increases the osmolarity in that region compared with the
intestinal lumen and drives the osmotic absorption of water.
Absorption of glucose, and the obligatory increases in absorption of
NaCl and water, helps to compensate for excessive diarrheal losses
of salt and water.
23. • Principle: In humans, the volumes of the body
fluid compartments are measured by the
dilution method.
• The basic principle underlying this method is
that a marker substance will be distributed in
the body fluid compartments according to its
physical characteristics.
24. The following steps are used to measure volumes of
body fluid compartments by the dilution method:
1. Identification of an appropriate marker
substance.
Required criteria of tracers to measure the
following compartments:
• Plasma: not permeable to capillary membranes,
e.g., albumin
• ECF: permeable to capillary membranes but not
cell membranes,e.g., inulin, mannitol, sodium,
sucrose
• Total body water: permeable to capillary and cell
membranes, e.g., tritiated water, urea
25.
26. 2. Injection of a known amount of the marker
substance. The amount of marker
• substance injected into the blood is measured
in milligrams (mg), millimoles (mmol), or units
of radioactivity (e.g., millicuries [mCi]).
27. 3. Equilibration and measurement of plasma
concentration. The marker is allowed to
• equilibrate in the body fluids, correction is
made for any urinary losses during the
equilibration period, and the concentration of
the marker is then measured in plasma.
29. • V × C = A, therefore V = A/C
• V = Volume of the compartment to be
measured
• C = Concentration of the tracer in the
compartment to be measured
• A = Amount of the tracer
30. • If 300 mg of a dye was injected intravenously
and at equilibrium,and the concentration in
the blood was 0.05 mg/mL, the volume of the
compartment that contained the dye would
be:
• Volume = 300 mg/ 0.05 mg/mL or 6000 mL
31. Q
• If 1 milliliter of a solution containing 10 mg/ml
of dye is dispersed into chamber B and the
final concentration in the chamber is 0.01
milligram for each milliliter of fluid, the
unknown volume of the chamber would be?
32. • A patient is injected with 500 mg of mannitol.
After a 2-hour equilibration period, the
concentration of mannitol in plasma is 3.2
mg/100 mL. During the equilibration period,
10% of the injected mannitol is excreted in
urine. What is the patient's ECF volume
33. Q
• A 65-kg man is participating in a research study for
which it is necessary to know the volumes of his
body fluid compartments.
• To measure these volumes, the man is injected
with 100 mCi of D2O and 500 mg of mannitol .
During a 2-hour equilibration period, he excretes
10% of the D2O and 10% of the mannitol in his
urine.
• Following equilibration, the concentration of D2O
in plasma is 0.213 mCi/100 mL and the
concentration of mannitol is 3.2 mg/100 mL.
• What is his total body water, his ECF volume, and
his ICF volume? Is the man's total body water
appropriate for his weight?
34.
35. The man's total body water is 42.3 L, which is
65.1% of his body weight
(42.3 L is approximately 42.3 kg; 42.3 kg/65 kg =
65.1%). This percentage falls within the normal
range of 50% to 70% of body weight.
36. Distribution of intravenously
administered fluids
• Vascular compartment: whole blood, plasma,
dextran in saline.
• ECF: saline, mannitol. At least 2/3 of the fluid
would enter the ISF.
• Total body water: D5W–5% dextrose in water.
Once the glucose is metabolized,the water
would distribute 2/3 ICF, 1/3 ECF.
39. Q
• A woman runs a marathon on a hot September
day and drinks no fluids to replace the volumes
lost in sweat. It is determined that she lost 3 L of
sweat, which had an osmolarity of 150 mOsm/L.
• Before the marathon, her total body water was
36 L, her ECF volume was 12 L, her ICF volume
was 24 L, and her body fluid osmolarity was 300
mOsm/L.
• Assume that a new steady state is achieved and
that all of the solute (i.e., NaCl) lost from her
body came from the ECF. What is her ECF volume
and osmolarity after the marathon?
43. • Qf = k [(Pc + πIF) – (PIF + πC)]
• Qf = fluid movement
• k = filtration coefficient
44. Questions
1. Given the following values, calculate a net
pressure:
PC = 25 mm Hg
PIF = 2 mm Hg
πC = 20 mm Hg
πIF = 1 mm Hg
2. Calculate a net pressure if the interstitial
hydrostatic pressure is –2 mm Hg.
45. EDEMA
The edematous state requires two conditions for
its development and maintenance:
1. An increase in the Starling forces, which
promote the movement of fluid from the
vascular compartment to the interstitium
2. Retention of sodium and water by the kidney
46. Peripheral edema expresses itself in
two different forms
1. Non-pitting edema: This is often referred to as a
lymphedema which is a disturbance of the lymphatic
system. This can develop after the removal of systemic
tissue such as after a mastectomy. Non-pitting edema
does not respond to diuretics.
2. Pitting edema: This is the classical, most common type
observed clinically. Pitting edema generally responds to
diuretic therapy. Common causes include nephrotic
syndrome, congestive heart failure, cirrhosis,
pregnancy, idiopathic edema, and nutritional edema
47. Packed Cell Volume
• Percentage of the cellular elements (RBC’s,WBC’s and
platelets) in the whole blood.
• PCV is considered equivalent to the volume of packed
red cells or the so called haematocrit value, as the
volume of WBC’s and platelets is very less.
• In 100ml of blood PCV is 45ml.
• Haematocrit is the volume of RBC’s expressed as
percentage
• Haematocrit value in males is about 45%
Haematocrit value in females about 42%
48. HEMATOCRIT (Htc)-Important Diagnostic Measurement
• Is the fraction of the
blood volume made up
of the formed elements
(mainly RBC)
• Is determined by the
centrifuging
heparinised/anticoagulat
ed blood in a standard
calibrated tube of a small
diameter
50
•When blood is allowed to clot or
coagulate, the suspending
medium is referred to as serum
51. HEMATOCRIT
• Values
– Males: 40 – 54 vol% (mean – 47%; 0.47)
– Females: 38 – 46 vol% (mean – 42%, 0.42)
• ↑ in persons leaving at high altitudes, polycythemia, etc.
• ↓ in anemia, leukemia, bone marrow failure
• Importance
– Determines blood viscosity
– ↑ Htc → ↑ resistance to blood flow, load on the heart & BP
53
Determination of hematocrit values is a simple and important screening diagnostic
procedure in the evaluation of hematological disease
The contribution of the WBC to hematocrit is only 0.08%. WBCs are lighter than the RBCs,
they form a thin whitish layer between the sedimented RBCs and the plasma.
