Intravenous Fluids: Composition and Indications Flashcards
What are the two broad categories of IV fluids?
Crystalloids and colloids
What do crystalloid solutions contain?
Water, electrolytes, and/or glucose
What do colloid solutions primarily include?
Albumin and blood products
What are the three types of IV solutions based on tonicity?
- Isotonic
- Hypotonic
- Hypertonic
What is the general use of isotonic solutions?
To treat extracellular fluid (ECF) volume depletion
What is the primary use of hypertonic solutions?
To correct symptomatic hyponatremia
Why is hypertonic saline used in trauma settings?
It decreases the intracranial pressure in patients with head trauma and for patients following burns
What is D5W?
5% dextrose in water
What are the indications for dextrose in water (D5W)?
- To replace deficits of total body water in hypernatremia
- To provide energy and prevent starvation ketosis
- To treat hypoglycemia
- To mix with amino acid solution in total parenteral nutrition
- Do not give to a patient with syndrome of inappropriate antidiuretic hormone
- Do not use alone to expand ECF volume in a hypovolemic patient
What is the composition of normal saline (0.9%)?
154 mEq/L Na(^+) and Cl(^-)
What is the effect of 1 L of normal saline infusion in a healthy individual?
Expands intravascular volume by 20%
What is the typical duration that normal saline persists in the body?
Up to 6 hours
What is the primary composition of Ringer’s lactate?
Contains lactate and is considered physiologic saline
What are the indications for Ringer’s lactate?
- To replace isotonic fluid loss in burns or surgery
- To correct metabolic acidosis with hypokalemia
- Do not use to expand ECF volume alone
- Do not use in a patient with lactic acidosis
- Do not use in renal failure patients
- Use cautiously in hepatic failure
What is the primary role of albumin in IV therapy?
To maintain intravascular oncotic pressure
What is the half-life of albumin in the intravascular compartment?
16–14 hours
What are the indications for albumin use?
- To expand plasma volume when crystalloids fail
- To treat severe edematous patients with nephrotic syndrome
- To prevent hemodynamic instability after large-volume paracentesis
- To prevent kidney impairment in spontaneous bacterial peritonitis
What is the typical composition of dextran solutions?
Dextran 40 and 70
What are examples of balanced electrolyte solutions?
- Ringer’s lactate
- Ringer’s acetate
- Plasma-Lyte A
What is the primary disadvantage of using normal saline in critically ill patients?
Causes hyperchloremic metabolic acidosis and acute kidney injury
What does the term ‘COP’ stand for in the context of colloids?
Colloid oncotic pressure
What is the effect of hypotonic solutions on sodium levels?
Do not use in a patient with hypotonic hyponatremia
What is the osmolality of 3% NaCl?
1026 mOsm
How is Ringer’s lactate metabolized in the body?
Converted to HCO(_3^-) in the liver
What is the primary use of hypertonic saline?
To treat symptomatic hyponatremia
What should be avoided when administering D5W?
Do not give to a patient with syndrome of inappropriate antidiuretic hormone
Fill in the blank: Dextrose in saline provides _______ and free water.
Na(^+) and Cl(^-)
What is one indication for albumin use?
To expand plasma volume when crystalloids have failed to correct acutely diminished intravascular volume.
In what condition should albumin be used to treat severe patients?
To treat severe edematous patients with nephrotic syndrome resistant to potent diuretic therapy.
What is a contraindication for using albumin?
Do not use to treat hypoalbuminemia due to malnutrition unless the patient has protein losing enteropathy.
What are the goals of fluid therapy?
- To normalize hemodynamic and electrolyte abnormalities
- To maintain daily requirements of fluids and electrolytes
- To replace previous fluid and electrolyte losses
- To replace ongoing fluid and electrolyte losses
- To provide nutrition
- To provide a source for IV drug administration
True or False: Crystalloids are preferred to colloids in fluid therapy in most situations.
True.
What complications can arise from fluid therapy?
- Fluid overload
- Electrolyte disturbances
- IV catheter-associated infections
- Hyperkalemia
- Hyperchloremic metabolic acidosis
- Acute kidney injury
How is infused fluid distributed in body compartments?
Approximately 60% of body weight is total body water, with two-thirds in ICF and one-third in ECF.
How much of the infused D5W remains in the intravascular compartment?
84 mL (25%).
Fill in the blank: For a 70 kg man, the total daily water requirement is about ______ mL.
1000–2000 mL.
What is the estimated daily requirement for Na+ in maintenance therapy?
1–2 mEq/kg/day.
What fluid is preferred for patients with severe dehydration?
Normal (0.9%) saline.
What is the recommended initial fluid therapy for septic shock?
Isotonic saline.
What is the therapeutic goal for hemorrhagic shock due to gastrointestinal bleeding?
Restore circulating blood volume and adequate Hb levels.
What is the management approach for traumatic hemorrhagic shock?
Use damage control resuscitation, limit crystalloid use, and transfuse blood products in ratios similar to whole blood.
What characterizes the rescue phase of fluid therapy?
Life-threatening shock requiring rapid fluid bolus therapy.
What is the main goal of fluid therapy in ARDS?
Minimize increases in pulmonary hydrostatic pressure.
How should fluid management be adjusted in critically ill patients?
It should vary depending on the hemodynamic status.
What is the total volume remaining intravascularly after 1 L of 0.45% NaCl infusion?
167 mL.
Fill in the blank: The distribution of 1 L of D5W results in ______ mL in the intravascular compartment.
84 mL.
What fluid therapy is suggested for patients with ARDS?
Colloid rather than crystalloid infusion is suggested.
What does the optimization phase of fluid therapy involve?
Fluid boluses of 250–500 mL in 15–20 min to restore cardiac output and organ perfusion.
What is the role of vasopressor support in septic shock?
Required if crystalloids alone do not improve blood pressure.
True or False: The phases of fluid therapy are mutually exclusive.
False.
What is the primary goal during the stabilization phase of septic shock management?
Restore cardiac output and organ perfusion
This involves maintaining adequate intravascular volume.
What is the initial fluid therapy for a patient in septic shock?
Normal saline, with rapid infusion of at least 1 L within an hour
Continue with 150–200 mL/h until acceptable blood pressure and tissue perfusion are achieved.
At what hemoglobin level should a patient receive a blood transfusion?
Below 7 g/dL
Transfusion is not necessary if hemoglobin is above this threshold.
When should 5% albumin be infused in a septic shock patient?
If blood pressure does not improve with normal saline and there is trace edema
Albumin may help restore blood pressure and tissue perfusion.
Which statement about hyperchloremia is CORRECT?
E. All of the above
Each statement (A, B, C, D) regarding hyperchloremia’s effects is correct.
What fluid is appropriate for a patient with multiple electrolyte problems due to nonrenal losses?
Ringer’s lactate
This fluid contains essential electrolytes needed for correction.
What might happen if D5W is administered to a patient with hypokalemia?
Further lowering of serum [K(^+)]
This can lead to weakness and arrhythmias.
What would be the consequence of continuing Ringer’s lactate in a patient with acute kidney injury?
Hyperkalemia
Due to the kidneys’ inability to excrete potassium.
What is the appropriate IV fluid for a patient with a serum glucose level of 1400 mg/dL?
Normal saline
This addresses hemodynamic instability before correcting hypertonicity.
Match the following case with the appropriate IV fluid: A 40-year-old patient with septic shock.
0.45% saline
This is the correct fluid for this condition.
What fluid should be given to a postoperative patient with serum [Na(^+)] of 120 mEq/L?
D5 ½ (0.45%) normal saline
This helps correct hyponatremia and provides maintenance fluid.
What should be the estimated daily urine output for a 70 kg patient undergoing elective surgery?
Approximately 1.5 to 2 L
This is based on average urine output guidelines.
