2. Outline
Physiology of body water
Indication of IVF therapy
Type of IVF
Fluid imbalance
Determining Appropriate IVF
Examples
Remember
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3. Total Body Water
*Body water represent 60% of adult male body weight
and 50% of adult female body weight which distributed in
two body compartment .
*The two body compartment are IC and EC .
*The EC compartment subdivided into interstitial and IV
spaces.
*The IV space subdivided into arterial and venous side.
*The body water distributed in the two compartment
according to one third and two third rule.
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6. Where is my bolus going?
1L D5W distributed into Total Body Water
Free water
content
ICF ECF Interstitial Intravascular
D5W 1000cc 660cc 340cc 226cc 114cc (11%)
½ NS 500 cc 330 cc
670cc
{170 free
water+500}
330cc
+ 114 cc from
free water=444cc
170 cc + 56 cc
from
free water
=226 cc
NS 0 0 1000cc 660cc 330cc (33%)
Normal saline has no free water and is confined to ECF
space; this is why it is the preferred IVF for resuscitation!28/3/1436
7. Parameter of
TBW
Interstitial : sk &mm
texture and skin
elasticicty
ICF : Serum
osmolality
Arterial side :
BPVenous side : CVP
General : body weight and urea & creat & urine
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9. Water Input and Output of the “Normal” Adult
Minimal Obligatory Daily Water input:
Ingested water: 500 mL
Water content in food: 800 mL
Water from oxidation : 300 mL
TOTAL: 1600mL
Minimal Obligatory Daily water output:
Urine: 500 mL
Skin: 500 mL
Respiratory tract: 400mL
Stool: 200 mL
TOTAL: 1600mL
→ Average adult input/output is 30-35mL / kg / day
(2.4L/day)
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10. Fluid loss
Sensible loss
*Measurable e.g.: urine
Insensible Loss
*Nonmeasurable e.g.: skin & lung
*Approximately 10mL / kg per day or 30 to 50 mL /h: less
if ventilated, more if febrile.
*Fever increases insensible loss by 200 cc /day for each
degree (C) above 37( nearly 8 cc / h ).
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11. Daily Electrolyte Requirements
Na
* Na: 1-3 meq /kg/day(70 kg male requires 70-210 meq NaCl, 2600 cc fluid
per day).
* 0.45% saline contains 77 meq NaCl per liter. 2.6 x 77 = 200 meq
*Thus, 0.45% saline is usually used as MIVF assuming no other volume or
electrolyte issues.
Potassium
* Potassium: 1 meq / kg /day
*K can be added to IV fluids. Remember this increases osm load.
*20 meq / L is a common IVF additive.
* This will supply basal needs in most pts who are NPO.
*If significantly hypokalemic, order separate K supplementation.
*Oral potassium supplementation is always preferred when feasible.
Chloride: 60-150 meq Bicarb: 1 meq/kg/day
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12. Useful definitions
*Normuria : urine output about 1 – 2 L per day.
*Oliguria : urine output less than 500 mL/day.
*Anural : urine output <50 mL/day.
* Polyuria : urine output exceeding 3 L/day.
*Hemostasis : complex process which changes blood from a fluid to a solid
state.
*Homeostasis : maintenance of equilibrium state between cellular and
extracellular compartment composition.
*Serum osmolality : number of osmoles of solute per kg serum.
*Serum osmolarity : the number of osmoles of solute per litre of serum.
*Tonicity : the effective osmolality (the number of effective osmoles per kg
serum. 28/3/1436
13. Electrolytes
*Electrolytes are chemical compounds in solution that have the
ability
to conduct an electrical current .
*Distributed in different concentrations in IC & EC
compartment
*Two types :
1- cations : positively charged electrolytes as Na /K/ Ca/
Mg/ H ions.
2- anions : negatively charged electrolytes as cloride /
bicarbonate / phosphate /sulfate . 28/3/1436
15. Regulation of body fluid compartment
*Homeostasis : maintenance of equilibrium state between
cellular and extracellular compartment composition.
* Homeostatic mechanism is a function of kidneys & CVS &
lung & supra renal & thyroid and parathyroid gland & pituitary
gland through RAAS & ADH and thirst & osmoreceptors and
baroreceptors & ANP.
*movement of particles through the cell membrane occurs
via the following transport mechanisms:-
1- Passive transport ( osmosis & diffusion & filtration ) .
2- Active transport as Na - K pump. 28/3/1436
16. Regulation of body fluid compartment
Diffusion : substances movement from area of higher
concentration to one of lower concentration eg O2 and
co2 across A-a membrane.
Filtration : passage of water and electrolytes in response
to hydrostatic & oncotic pressure e.g. as occur from
arterial capillary bed to interstitial space .
Osmosis : the movement of fluid through semipermeable
membrane from low osmolality to high osmolality.
Active transport : active movement of substances
across cell membrane against pressure gradient e.g. Na -
k pump.
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17. Osmolality and Osmolarity
*Serum osmolality: measures the body's electrolyte-water
balance.
*Osmolality and osmolarity are measures that are
technically
different, but functionally the same for normal use.
* Osmolality (with an "ℓ") is a measure of the osmoles (Osm)
of solute per kilogram of solvent (osmol / kg or Osm/kg).
*Osmolarity (with an "r") is defined as the number of
osmoles of solute per litre (L) of solution (osmol/L or Osm/L).
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18. *Serum osmolality : number of osmoles per kg serum ( normally 285
+_ 10 mosm / kg)
*Serum osmolality = 2 Na + urea/2.8 + glucose / 18 (all in mmol )
*Serum osmolarity (with an "r") is defined as the number of osmoles of
solute per litre (L) of serum (osmol/L or Osm/L).
*Osmolality of ECF and ICF is always equal.
*Effective osmoles : osmol which have osmotic pressure as Na &
Glucose .
*Non effective osmoles : osmol which have no osmotic pressure as
urea.
Tonicity : the effective osmolality and is equal to the sum of effective
osmoles in serum.
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19. Contents of IV Fluid Preparations
Na
(mEq/L)
K
(mEq/L)
Cl
(mEq/L)
HCO3
(mEq/L)
Dextrose
(gm/L)
mOsm/L
D5W 50 278
½ NS 77 77 143
D51/2NS 77 77 50 350
NS 154 154 286
D5NS 154 154 50 564
Ringers
Lactate
(RL)
130 4 109 28 50 272
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20. Fluid shifting
1st space shifting: normal distribution of fluid between
both ECF and ICF compartment.
2nd space shifting: excesses accumulation of fluid in
interstitial space (edema).
3rd space shifting: accumulation of fluid in areas that
are normally have no or little amount of fluid and
normally not share in homeostasis (ascitis – burns –
bowel obstruction - massive bleeding into joint).
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21. Indication of IVF therapy
Purpose
The appropriate rate
Choice of replacement fluid
Replacement therapy (Resuscitation , Rehydration)
Purpose
The appropriate rate
Choice of replacement fluid
Maintenance Therapy
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22. Maintenance Therapy
Purpose
*Replace ongoing losses of water and electrolytes under normal
physiological conditions
* Used when the patient is not expected to eat or drink normally
for prolonged period of time
* In general, patients who are afebrile, not eating, not physically
active require less that 1 L of free water daily
* Patient’s with ESRD or edematous states (ex. cirrhosis, heart
failure) require less maintenance due to decreased output
and/or altered fluid distribution
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23. Maintenance Therapy
3 approaches to determine the appropriate rate:
1) Calculate maintenance based on average requirement of 35 cc / kg / day
2) “4/2/1” rule
4 ml/kg/hr for the first 10 kg (0-10kg)
2 ml/kg/ hr for the next 10kg (11-20kg)
1 ml/kg/ hr for remaining weight (21 kg and up)
3) Weight in kg + 40
EX; Pt weight 85 kg.
1- 85 kg x 35 cc/ kg / 24hr = 3L/24 hr = 125 cc / hr
2- 40 + 20 + 65 = 125cc/ hr
3- 85 + 40 = 125cc/ hr
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24. Maintenance Therapy
What type of fluid for maintenance?
* D51/2NS + 20 mEq KCl provides:
- avoid dextrose in patients with uncontrolled DM or
hypokalemia
- No much data to support addition of D5, however
can be added to prevent muscle catabolism
* Therefore, 1/2NS or D51/2NS + 20 mEq KCL would be
appropriate choices.
* adjust maintenance fluids based on serum sodium
concentration (ex. Change from 1/2NS to NS or D5NS if
hyponatremia develops)
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25. Replacement therapy
Purpose:
Correct existing abnormalities in volume
status or serum electrolytes
Objective parameters used to assess volume deficit:
• Blood pressure
• Jugular venous pressure
• Serum osmolality
• Sk &mm texture and skin elasticity
• urea & creat
• Urine sodium concentration
• Urine output
• Pre and post deficit body weight
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26. Parameter of TBW
Interstitial : sk &
mmmoisture and skin
elasticity
ICF : Serum osmolality
Arterial side : BPVenous side : CVP
General : body weight and urea & creat & urine
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27. Rate of Repletion
Severe volume depletion or hypovolemic shock
* Rapid infusion of 1-2L isotonic saline (NS), then reassess
parameters( HHS, DKA, sepsis and septic shock , hypovolemic shock)
Mild to moderate hypovolemia
* Estimate fluid losses:
– Average output 2.4 L /day for 70kg patient.
– estimate additional losses such as GI (diarrhea, vomiting) and
high fever.
* Choose rate 50-100mL/h greater than estimated losses.
* Select fluid based on type of fluid that has been lost and any co-
existing electrolyte disorders .
Replacement therapy
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28. Which Fluid to Choose?
1- Hypovolemia
* primary goal is volume expansion.
*NS or LR.
2-Dehydration (= hyperosmolality)
* primary goal is free water replacement.
*Use a hypotonic fluid usually 0.45% saline or D5W.
3-Hypernatremia use hypotonic solutions.
4- Hyponatremia use Isotonic or, in symptomatic patients,
hypertonic saline.
5- blood loss use Isotonic saline and blood .
Note: K or bicarbonate may need to be added in patients with hypokalemia o
metabolic acidosis.
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29. Type of IV solution
according to their tonicity
Isotonic Hypotonic Hypertonic
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30. Note: These can be dangerous in the
setting of cell dehydration.
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34. Hartmann's solution or compound sodium lactate
*crystalloid solution that is most closely isotonic with blood and
intended for intravenous administration.
*used to replace body fluid and mineral salts that may be lost for
a variety of medical reasons.
*Hartmann's IV Infusion is especially suitable when the losses
result in too much acid being present in the blood.
*Hartmann's solution is abbreviated as "CSL".
*It is very similar—though not identical to — lactated Ringer's
solution, the ionic concentrations of which differ.
*One litre of Hartmann's solution contains:
Na = 131 mmol/L& CL= 111 mmol/L & lactate = 29 mmol/L & K
= 5 mmol/L & CA = 2 mmol/L. 28/3/1436
35. Caution with use because sudden fluid shifts from
the IV space to cells can cause cardiovascular
collapse and increased ICP .
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37. Colloids
*large molecular weight solutions ,may be natural or
artificial ,have MW > 30,000 Daltons, do NOT readily
cross semi-permeable membranes.
*Used to increase vascular spacs rapidly by shifting fluid
from interstitial and IC compartment.
*They work well in reducing edema (p edema or cerebral
edema) while expanding the vascular compartment.
* Dextran / Albumin / Mannitol / HES are examples.
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38. Crystalloids
*Small molecular weight solutions made up of water
& electrolyte.
*Effective volume expander for a short period of time.
*Ideal for patient who need fluid volume replacement.
*NS / LR ARE examples.
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43. Volume depletion
Symptoms
* Three sets of symptoms may occur in hypovolemic patients:-
1-Those due to volume depletion.
2-Those related to the type of fluid lost.
3-Those due to the electrolyte and acid-base disorders which
can accompany volume depletion.
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44. Volume depletion
* Symptoms induced by hypovolemia are primarily related to
decreased tissue perfusion.
*The earliest complaints include lassitude, easy fatigability,
thirst, muscle cramps, and postural dizziness.
*More severe fluid loss can lead to abdominal pain, chest
pain, or lethargy and confusion due to ischemia of the
mesenteric, coronary , or cerebral vascular beds,
respectively.
* These symptoms are usually reversible, although tissue
necrosis may develop if the low-flow state is allowed to
persist
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45. Volume depletion
Physical examination
* Although relatively insensitive and nonspecific, certain
findings on physical examination may suggest volume
depletion.
*A decrease in the interstitial volume: can be detected by
the examination of the skin and mucous membranes
( decreased skin turgor- dry skin- dry axilla -dry tongue
and oral mucosa ).
*A decrease in IV volume : can be detected by Decrease
in the systemic blood pressure and Decrease in The venous
pressure in the jugular veins.
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46. Hypernatremia
Rate of fluid administration mL /h = water deficit x 10 ÷ (serum Na -
140)÷ 24
+
Obligatory water output from sweat and stool, which is approximately
30 to 40 mL /h.
*Rate of lowered serum sodium per day =10 meq /L per day
*The water deficit should be replaced over at least (serum Na -140) ÷ 10
= days, or day/24 = hours
*Obligatory water output from sweat and stool, which is approximately
30 to 40 mL /h.
Serum [Na]
*Water deficit = Current TBW x (——————— - 1)
140
*Current TBW= W X male 60% or female 50%28/3/1436
47. Hyponatremia
1)Na deficit (total needed) = Current TBW x (desired Na -
serum Na)
2) desired rate/hr = Amount needed to increase serum
level by 0.5 meq/L/hr = Current TBW x 0.5
3) 3% hypertonic saline contains 513 meq /Liter
[desired rate/hr]/513 x 1000 = ml/hr
4) Length of infusion = Na deficit / desired rate/hr =
hours
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48. Determining Appropriate IVF
Step 1: Assess volume status
Step 2: Determine Access
Step 3: Select Type of Fluid
Step 4: Determine Rate
==============================================
=======
Step 1: Assess volume status
*What is the volume status of my patient?
*Do they have ongoing losses?
*Can my patient take PO safely?
*Are the NPO for a reason?
Step 2: Determine Access
*Peripheral IV
*Central line 28/3/1436
49. Determining Appropriate IVF
Step 3: Select Type of Fluid
Hypovolemic Patient
* Use Normal Saline for goal of volume resuscitation .
•On surgery or if going to administer more than 3-4L
often use LR. (Addition of lactate that is metabolized to
bicarbonate to help buffer acidosis) .
Hypervolemic Patient
*Avoid additional IVF
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50. NPO Patient euvolemic
*Administer maintenance fluids.
*For average adult NPO for more than 6-12 hours, consider
D51/2NS.
*Consider pt co-morbidities .
*Constantly reassess, at least 2x day or with any change.
*Don’t give fluids blindly ie: if the patient is pre-procedure but is old
(predisposed to fluid overload because of stiff LV) or has history of
CHF, be careful.
Normal PO Intake
*No need for fluids if they are taking PO without problems!
*Avoid IVF
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52. Determining Appropriate IVF
Step 4: Determine Rate
Maintenance Therapy
1) Calculate maintenance based on average requirement
of 35cc/kg/day
2) “4/2/1” rule
4 ml/kg/hr for the first 10 kg (0-10kg)
2 ml/kg/hr for the next 10kg (11-20kg)
1 ml/kg/hr for remaining weight (21 kg and up)
3) Weight in kg + 40
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53. Step 4: Determine Rate
Replacement therapy
Severe volume depletion or hypovolemic shock
* Rapid infusion of 1-2L isotonic saline (NS), then reassess parameters (
HHS, DKA, sepsis and septic shock , hypovolemic shock)
Mild to moderate hypovolemia
* Estimate fluid losses:
– Recall: Average output 2.4L/day for 70kg patient
– estimate additional losses such as GI (diarrhea, vomiting) and high
fever.
* Choose rate 50-100mL/h greater than estimated losses
* Select fluid based on type of fluid that has been lost and any co-existing
electrolyte disorders
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55. 1- 35 y/o female NPO for elective lap chole . Afebrile
HR 72 BP 120/80 Wt 85 kg. Na 140 K 4.0.
Fluid Orders:
•D5 0.45% saline with 20meq KCl @ 125 cc/hr.
--------------------------------------------------------------------------
2- 40 y/o with idiopathic cardiomyopathy. EF = 15%.
Crackles ½ up both lung fields to auscultation and
edema of both lower extremities, JVP elevated. Na:
130, K: 5.1, Cr: 2.3. IVF?
Fluid Orders:
*This pt is both water (hyponatremia) and salt (edema)
overloaded and will require dieresis.
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56. 3- 55 y/o male. In ED for fever and rigors. T 39.0, HR 120, BP
70/40 RR 35 WBC: 25,000; UA: 500 WBC/ hpf , many
bacteria.
Fluid orders:
* 0.9% saline wide open.
* This means a bag of saline in a pressure device through a
large bore iv, probably two in this case.
*Reassess for clinical response
---------------------------------------------------------------------------------
4- 89 y/o nursing home pt. admitted for diverticulitis. T 38.0 HR
90 BP 145/85. Wt 70 kg Na: 140, K: 3.7. Not eating.
Fluid Orders:
* Basal needs 70 + 40 = 110cc/hr
* Additional loss from fever = approx. 10 cc/hr
* Total rate = 120 cc/hr: IVF?
* (D5) 0.45% saline with 20 meq KCl 28/3/1436
57. 5-50 y/o with massive hematemisis, SBP 80 HR 130 IVF?
Fluid Orders:
* 0.9% saline WIDE OPEN through two large bore IVs.
*O neg STAT
*Type and cross 6 units PRBC STAT
-------------------------------------------------------------------------
6-65 y/o male hospitalized with pneumonia. Temp 38.5, HR 72,
BP 125/72. Wt 75 kg. Na:165 K: 4.0.
Fluid Orders:
*Basal needs 115 cc/hr + 12 cc/hr for fever.
Also:
* Free water deficit of (.6)(75)[(165/140) – 1] =
7.6 liters.
* IV # 1: 0.45% saline @ 130 cc/hr.
* IV # 2: D5W @ 150cc/hr for 50 hrs.
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58. 7- 30 y/o male admitted for ITP. Platelets 6, T 37.0,
HR 72, BP 120/80, Wt 80 kg. Eating well.
Fluid Orders:
NO IVF orders needed.
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60. 1- If the gut works use it.
2- Do not use IVF if they are unnecessary
3- Your fluid orders are incomplete until you have ordered
monitoring labs (electrolyte, Cr, etc), I/O, daily weights.
4-Think about why you ordering IVF
(NPO/Volume deficit/ On going losses/Specific goal to fluid
therapy eg hydration prior contrast dye)
5-The basic fluid, i.e. isotonic, hypotonic, hypertonic,
should be clear.
6-Complications of fluid therapy
(Fluid overload/ Electrolyte disturbances/ Line infections).
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61. 7- D5 ½NS is inappropriate for hypovolemic pt ( dextrose
gets almost immediately metabolized to water and CO2 when
it enters the circulation so it is not osmotically active for too
long)
8- In general, there are 4 types of patients when it comes to
administering IV fluids:
* Hypovolemic (Pneumonia, Sepsis, Hemorrhage,
Gastroenteritis).
* Hypervolemic (CHF, renal failure, cirrhosis ).
* NPO (surgical patient, euvolemic waiting surgery, unsafe
swallow)
* Eating/drinking normally
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62. 9- Consider appropriateness of IVF daily in each pt
e g :
*Hypovolemia use Isotonic fluid as NS or LR .
*Dehydration use hypotonic fluid as 0.45% saline or D5W .
•Hypernatremia use hypotonic solutions .
*Hyponatremia use Isotonic or, in symptomatic pt, hypertonic
saline.
*blood loss use Isotonic saline then blood .
10- K may need to be added in patients with hypokalemia and
bicarbonate in severe metabolic acidosis
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