TOPIC 12
Fluid and
electrolytes replacement
Introduction
Hospitalized patients often have conditions that
impair their ability to regulate their hydration status. Improper fluid
management leads to significant morbidity and mortality.
In all cases,
treatment is directed toward correction of the underlying cause.
Mild deficits can be
corrected using the appropriate oral rehydration or electrolyte solution.
Tonicity in living systems
If a cell is placed in a hypertonic
solution, water will leave the cell, and the cell will shrink. In an isotonic
environment, there is no net water movement, so there is no change in the size
of the cell. When a cell is placed in a hypotonic environment, water will enter
the cell, and the cell will swell.
At the end of
session, participants will be able to:
1. Explain oral replacement of fluid
2 Explain intravenous replacement of electrolytes
Fluid management
• Oral
Rehydration- safest and most effective treatment in alert clients/patients
- 1.500 ml / day
- 30 ml/kg body weight
• Intravenous
Therapy if fluid deficit is severe clients unable to ingest fluids
Tonicity
The osmolality of the solution
• Isotonic
fluids - those with the same osmolality as the cell interior
Less than 270 mOsm/kg
(mmol/kg)
Hypotonic fluids - those that contain more water than the cell interior
275-295 mOsm/kg (mmol/kg)
• Hypertonic
fluids - those that contain less water
than the cell interior
More than 300 mOsm/kg (mmol/kg)
Type
of IV fluids
INTRAVENOUS FLUID AND ELECTROLYTE REPLACEMENT
· Fluid replacement therapy is used to correct many fluid and
electrolyte imbalances. The amount and type of solution used is determined by
patient requirements and laboratory results.
· Hypotonic solutions, such as 5% dextrose in water and 0.45%
NaCl, provide more water than electrolytes, diluting the ECF and producing
movement of water from the ECF to the ICF.
· Administration of an isotonic solution, such as lactated
Ringer’s and 0.9% NaCl, expands only the ECF. There is no net loss or gain from
the ICF.
· A hypertonic solution initially raises the osmolality
by the ECF and expands it, making them useful in the treatment of hypovolemia
and hyponatremia.
· KCl, CaCl, MgSO4, and HCO3–
are common additives to the basic IV solutions.
Plasma expanders stay in the vascular space and increase the
osmotic pressure.
A. CRYSTALLOIDS – solutions with small molecules that
flow easily from the bloodstream into cells & tissues.
1. Isotonic
solution – has the same solute concentration
as another solution
ex: Normal Saline, Lactated Ringer’s, D5W
•
Normal
Saline (0.9% Sodium Chloride)
- expands
intravascular volume
- used with
blood transfusion
- replaces large
sodium losses (burns)
- replaces water
lost from extracellular fluid
•
Lactated
Ringer’s
- similar to plasma electrolytes
except magnesium
- replaces fluid losses from
burns and lower GIT
- Fluid of choice for acute
blood loss
•
D5
Water
- replaces water losses
- provides free water necessary
for cellular rehydration
- lowers serum sodium in
hypernatremia
Hypotonic solution
– solutions that have lower osmolality (less than 275 mOsm/L) than body fluids.
ex: 0.45% NaCl,
0.33% NaCl, D2.5% W, 0.225% , NaCl
. Hypertonic
solutions – solutions that have higher osmolality (greater than 295 mOsm/L)
than body fluids
ex: D5 NaCl, D5 0.45% NaCl
D5LR
D10 Water
3 % sodium chloride
corrects serious
sodium depletion
•
D5
0.45% NaCl
- DKA (glucose below 250mg/dl)
D5 0.9% NaCl
- hypotonic
dehydration
- SIADH
- temp for shock
before expanders
- don’t use in
cardiac & renal ds
(pulmonary edema
& heart failure)
•
D10 W
- for nutrition
with glucose
- water
replacement
- monitor serum glucose
hyperglycemia
. COLLOIDS/ PLASMA EXPANDERS
– pulls fluid from the interstitial
compartment into the vascular compartment.
ex: Albumin, Dextran
Common
symptoms of mild dehydration include:
- dry mouth, thirst ,headache,dry eyes, dry, dark coloured urine,
dizziness and, fatigue
healthy adults can rehydrate by
drinking: water, clear broth, diluted juices,
sports drink
ORS
is a liquid solution. It’s designed to be consumed by mouth.
If
a person is unable to drink due to vomiting, nasogastric feeding might be used.
This delivers the ORS via a nasogastric tube, which is inserted through the
nose and into the stomach
|
Date/
Time
3/3/23
|
Intake
|
mt
|
Output
|
Amt
|
|
7 -3
|
juice
water
D5 Nacl
|
160
480
600
|
urine
vomitus
drainage from chest tube
diarrhea
|
750
50
100
150
|
- Urine has been passed
- Pulse is strong
Evidence based practice
Accurately recording intake and
output is still an unreliable measure of actual fluid balance.
Measuring daily weight is a better I/O
chart
The importance takes
fluid replacement a priority when you're physically active. Drinking enough fluids will help to maintain
your concentration and performance, increase your endurance, and prevent
excessive elevations in heart rate and body temperature. It's all about
sufficient hydration.
Signs and Symptoms of Dehydration
Severe
Dehydration
One or
more danger signs:
- Lethargic or unconscious
- Absent or weak pulse
- Respiratory distress
OR at least two of the following:
- Sunken eyes
- Not able to drink or drinks poorly
- Skin pinch goes back very slowly
Some
Dehydration
No danger
signs AND at least two of the following:
- Irritable or restless
- Sunken eyes
- Rapid pulse
- Thirsty (drinks eagerly)
- Skin pinch goes back slowly
No
Dehydration
Signs:
- Awake and alert
- Normal pulse
- Normal thirst
- Eyes not sunken
- Skin pinch normal
Rehydration
Oral Rehydration Guidance: No to Some Dehydration
- Give oral rehydration solution (ORS) immediately to dehydrated
patients who can sit up and drink. If ORS is not available, you should
provide water, broth, and/or other fluids. You should not provide drinks
with a high sugar content, such as juice, soft drinks, or sports drinks,
because they could worsen diarrhea.
- Offer ORS frequently, measure the amount drunk, and measure
the fluid lost as diarrhea and vomitus.
- Give small, frequent sips of ORS to patients who vomit, or
give ORS by nasogastric tube.
- Make ORS with safe water, which is water
that has been boiled or treated with household bleach or a chlorine
product using the dose recommended in the product’s instructions, at
least 15 minutes before adding prepackaged oral rehydration salts.
To make the solution, mix
the oral rehydration salts (a prepackaged sachet of glucose and electrolytes)
with 1 liter of safe water.
- A rough estimate of oral rehydration rate for older children
and adults is 100 ml of ORS every 5 minutes, until the patient stabilizes.
- The approximate amount of ORS (in milliliters) needed over 4
hours can also be calculated by multiplying the patient’s weight in kg by
75.
- If the patient requests more than the prescribed ORS solution,
give more.
- Patients should continue to eat a normal diet or resume a
normal diet once vomiting stops.
- For infants: encourage the mother to
continue breastfeeding.
Assessment
- Reassess the patient after 1 hour of therapy and then every 1
to 2 hours until rehydration is complete.
- During the initial stages of therapy, while still dehydrated,
adults can consume as much as 1,000 ml of ORS per hour, if necessary, and
children as much as 20 ml/kg body weight per hour.
- The volumes and time shown are guidelines
based on usual needs. If necessary, you can increase the amount and
frequency, or you can give the ORS solution at the same rate for a longer
period to achieve adequate rehydration. Similarly, you can decrease the
amount of fluid if the patient becomes hydrated earlier than expected.
- severe dehydration,
- stupor,
- coma,
- uncontrollable vomiting, or
- extreme fatigue that prevents drinking.
- For severe dehydration, start IV fluids immediately. If the
patient can drink, give ORS by mouth while the IV drip is set up. Ringer’s
lactate IV fluid is preferred. If not available, use normal saline or
dextrose solution.
- It is important to measure the amount of
IV fluids delivered and measure the fluid lost as diarrhea and vomitus.
Assessment
- Reassess the patient every 15–30 minutes and continue hydrating. The volumes and time intervals shown are guidelines
provided on the basis of usual needs.
- If necessary, you can increase the rate
of fluid administration, or you can give the fluid at the same rate for a
longer period, to achieve adequate rehydration. If hydration is not
improving, give fluids more rapidly; the patient may need 200 ml/kg or
more of intravenous fluids during the first 24 hours of treatment.
- You can decrease the amount of fluid if
the patient becomes hydrated earlier than expected.
- Give
more than the prescribed ORS solution if the patient requests more.
- Switch
from intravenous hydration to oral rehydration solution once hydration is
improved and the patient can drink. This will conserve IV fluids and
reduce the risk of phlebitis and other complications.
- You
can use nasogastric tubes to administer oral rehydration solution if the
patient is alert but unable to drink sufficient quantities independently.
*Repeat once if radial pulse is still very weak or not detectable
Signs of Adequate Rehydration
- Skin goes back normally when pinched
- Thirst has subsided
•
indicator of
fluid balance
•
What factors
affect accuracy of intake and output recording?
•
What measures
to take to ensure accurate daily weight measurements?
Drip Rates
• Your patient
needs an infusion of dextrose 5% in water at 125 ml/ hr. If the tubing set is
calibrated at 15 gtt/ml, what’s the drip rate?
Drip rate = total milliliters x drops factor total minutes
•
125 ml x 15 gtt/ml
60 mins
•
1,875 gtts
60 mins
•
x = 31.25 gtt/min = 31 gtt/min
Flow rate
•
Your patient
needs 250 ml of normal saline solution over 2 hrs. What’s the infusion rate?
•
Total Volume
ordered
number of hours
= 250 ml
2 hrs
= 125 ml/hr
Infusion Time
•
I f you plan to infuse 1 liter of
D5 W at 50 ml/hr, what’s the infusion time?
•
Volume to be infused
flow
rate
•
1 L = 1000 ml
•
1000 ml x =20hrs
50 ml/hr
Infusion Time
•
Your patient
requires 500 ml of normal saline solution at 80ml/hr. What’s the infusion time?
If the normal saline solution is hung at 5 am, what time will the infusion end?
•
X = 500 ml
80 ml/hr
= 11:15 a.m.
Hypertonic saline is a crystalloid intravenous fluid
composed of NaCl dissolved in water with a higher sodium concentration than
normal blood serum. Both 3% and 5% hypertonic saline (HS) is currently
FDA-approved for use in hyponatremia and increased intracranial pressure (ICP).
Patients with hyponatremia with severe features should have their serum sodium
gradually corrected with boluses of hypertonic saline. Patients should have
their serum sodium monitored at regular intervals and can receive multiple
boluses a day.[1]
Hypertonic saline should be discontinued once the
patient’s symptoms improve or they have an adequate increase in serum sodium.
Cerebral edema and elevated intracranial pressure (ICP) are significant causes
of morbidity and mortality in patients with intracranial tumors, cerebral
hematomas, traumatic brain injuries, cerebral infarcts, and intracranial
hemorrhages. Hypertonic saline increases the osmolarity of the blood, which
allows fluid from the extravascular space to enter the intravascular space,
which leads to decreases in brain edema, improved cerebral blood flow, and
decreased CSF production. Research shows that 3% hypertonic saline decreases
ICP similarly to 20% mannitol.[2] Both hypertonic
fluids have similar effects on haemodynamics. Hypertonic saline leads to
increases in serum sodium and has less of a diuretic effect than mannitol,
likely due to the increased serum sodium causing ADH release. Hypertonic saline
administered after mannitol in traumatic brain injury has also demonstrated
improvement of cerebral oxygenation in addition to lowering ICP.[3]
Due to there being
no guidelines regarding the administration of hypertonic saline for increased
ICP, various studies have used concentrations of 3% to 23.5% NaCl.[4]
MCQ
View
Dear students, please complete this quiz to test your understanding of Topic 12
Patient
scenario
1Your patient has had nausea, vomiting, and diarrhea for 4 days. The blood work shows this patient is dehydrated but their electrolytes have managed to stay within normal limits.
A What kind of solution is this patient's blood?
B What kind of fluid would you give this patient?
2 Your patient comes in with bilateral +2 pitting
edema on the lower extremities. The blood work confirms congestive heart
failure (CHF).
A What kind of solution is this patients’ blood?
B What kind of fluid would you give this patient?
3 Your patient is hypotensive, dizzy, weak, and reports
abdominal pain. The blood work confirms adrenal insufficiency.
A What kind of solution is this patient's blood?
B What kind of fluid would you give this
patient?
1. The
extracellular fluid (ECF) and intracellular fluid (ICF) compartments in total
body water are normally in a ratio of (ECF: ICF):
a.
1:1
b.
2:1
c.
1:2
d.
1:4
2.
The
dominant extracellular cation and anion are:
a.
Sodium
and bicarbonate
b.
Potassium
and chloride
c.
Potassium
and phosphate
d.
Sodium
and chloride
3.
The
dominant intracellular cation and anion are:
a.
Sodium
and bicarbonate
b.
Potassium
and phosphate
c.
Sodium
and chloride
d.
Potassium
and chloride
4.
The
recommended replacement for extracellular volume fluid loss is:
a.
Isotonic
(normal) saline solution
b.
Dextrose
and one-fourth normal saline solution
c.
Dextrose
and one-half normal saline solution
d.
One-half
normal saline solution plus 20 mEq potassium chloride per liter
Answers:
1. c.
2. d.
3. b.
4. a
Answer MEQ
1A Hypertonic
o
1B Isotonic
at first such as 0.9% NaCl (expand their volume and give them more to move or
shift around)
o
Hypotonic second,
usually 0.45% NaCl (shift the fluid into the cells)
o 2A Hypotonic
o
2B Hypertonic (shifts fluid out of the extracellular space and into the
vein, to be filtered out in the kidneys)
o
3A Isotonic
Adrenal insufficiency leads to loss of volume and loss of sodium
leaving the patient hypovolemic and hyponatraemic.
3B
Isotonic to help treat hypotension by expanding the volume of fluid in the
veins
References:
Sara, L.,
Justine, H. & Hayley, G. (2020). The Royal Marsden Manual of Clinical
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Sutherland-Fraser. S., Menna, D., Brigid, M. G. & Benjamin, L.
(2020). Perioperative Nursing : An Introduction (3rd ed). Australia: Elsevier
LeMone, P. & Burke, K.M. (2019). LeMone and Burke's
Medical-Surgical Nursing : Clinical Reasoning in Patient Care. (7th ed.). USA:
Pearson
Baranoski, S. (2020). Wound Care Essentials :Practice Principles
(5th ed). USA: Wolters Kluwer Health
Hinkle, J. L.
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