Podcast
Questions and Answers
What percentage of the body's weight is water?
What percentage of the body's weight is water?
60%
Which of the following fluids accounts for the larger portion of the body's water?
Which of the following fluids accounts for the larger portion of the body's water?
The extracellular fluid (ECF) consists of interstitial fluid and intravascular fluid.
The extracellular fluid (ECF) consists of interstitial fluid and intravascular fluid.
True
What is the name given to the pressure exerted by large molecular weight molecules or plasma proteins that tends to pull water into the intravascular space?
What is the name given to the pressure exerted by large molecular weight molecules or plasma proteins that tends to pull water into the intravascular space?
Signup and view all the answers
What is the normal osmolarity of canine blood?
What is the normal osmolarity of canine blood?
Signup and view all the answers
What is the primary factor for determining ECF volume and osmotic pressure?
What is the primary factor for determining ECF volume and osmotic pressure?
Signup and view all the answers
What is the normal pH of arterial blood?
What is the normal pH of arterial blood?
Signup and view all the answers
Acidosis is characterized by a high hydrogen ion (H+) concentration and is expressed as a high pH.
Acidosis is characterized by a high hydrogen ion (H+) concentration and is expressed as a high pH.
Signup and view all the answers
Hyperkalemia is a life-threatening condition that is less common than hypokalemia.
Hyperkalemia is a life-threatening condition that is less common than hypokalemia.
Signup and view all the answers
Which of the following is NOT a factor that can cause dehydration?
Which of the following is NOT a factor that can cause dehydration?
Signup and view all the answers
What are the three systems that control pH in the body?
What are the three systems that control pH in the body?
Signup and view all the answers
Hypertonic solutions are similar to plasma and do not cause a shift in fluids or cell structure.
Hypertonic solutions are similar to plasma and do not cause a shift in fluids or cell structure.
Signup and view all the answers
Which of the following is a contraindication for rapid fluid therapy?
Which of the following is a contraindication for rapid fluid therapy?
Signup and view all the answers
Which of the following routes of administration is NOT recommended for dehydrated, hypothermic, or hypotensive patients?
Which of the following routes of administration is NOT recommended for dehydrated, hypothermic, or hypotensive patients?
Signup and view all the answers
Which crystalloid solution acts as a buffer against acidosis?
Which crystalloid solution acts as a buffer against acidosis?
Signup and view all the answers
Dextrose 5% in water is a balanced solution that contains electrolytes and dextrose.
Dextrose 5% in water is a balanced solution that contains electrolytes and dextrose.
Signup and view all the answers
Which type of fluid is used for the treatment of hypovolemia or septic shock?
Which type of fluid is used for the treatment of hypovolemia or septic shock?
Signup and view all the answers
What is the formula for calculating fluid drip rate?
What is the formula for calculating fluid drip rate?
Signup and view all the answers
Which of the following is NOT a benefit of fluid administration during anesthesia?
Which of the following is NOT a benefit of fluid administration during anesthesia?
Signup and view all the answers
Overhydration can lead to restlessness, increased respiratory rate, increased lung sounds, and edema.
Overhydration can lead to restlessness, increased respiratory rate, increased lung sounds, and edema.
Signup and view all the answers
What is the term used to describe edema of the ocular conjunctiva, a sign of overhydration?
What is the term used to describe edema of the ocular conjunctiva, a sign of overhydration?
Signup and view all the answers
T.P.N. is a type of fluid therapy that can only be administered orally.
T.P.N. is a type of fluid therapy that can only be administered orally.
Signup and view all the answers
Study Notes
Fluid Therapy
-
Physiology:
- 60% of the body's weight is water (Total Body Water - TBW).
- Two-thirds of TBW is intracellular fluid (ICF).
- One-third of TBW is extracellular fluid (ECF).
- 75% of ECF is interstitial fluid (ISF).
- 25% of ECF is intravascular fluid (IVF).
- Neonates have ~80% of their weight as fluid.
-
Blood Volume:
- Dogs: 80-90 ml/kg
- Cats: 40-60 ml/kg
- Horses: 80 ml/kg
-
Average Plasma Concentrations (Dog vs Cat):
- Data provided in a tabular format
-
Intracellular Fluid (ICF):
- Fluid within the cells.
- Major electrolytes include potassium (K+), magnesium (Mg2+), and phosphates (HPO42-).
- Difficult to measure ICF electrolytes, so serum concentrations are measured.
-
Extracellular Fluid (ECF):
- In constant motion, carrying nutrients, oxygen, and electrolytes to reach cells.
- Removes waste products (homeostasis).
- Major electrolytes: sodium (Na+), chloride (Cl-), and bicarbonate (HCO3-).
-
Electrolytes (Potassium):
- Crucial for osmotic pressure within cells.
- Important for normal cell metabolism, and electrical potentials in muscles and nerves.
- Hypokalemia: Most common, requires supplementation.
- Hyperkalemia: Less common, life-threatening.
-
Electrolytes (Sodium):
- Attracts water, primary factor in ECF volume and osmotic pressure.
- Regulation of intake and excretion is via the kidneys.
- Hyponatremia: Influx of water into cells.
- Hypernatremia: Usually due to water loss (dehydration).
-
Acid-Base Balance:
- Regulation of hydrogen ion concentrations, expressed as pH.
- Normal pH of venous blood and ISF: ~7.35
- Normal pH of arterial blood: 7.4
- Major complications and death can occur if pH falls below <7.2 or rises above >7.6 for more than a few hours.
- Three systems control pH: blood buffers, lungs, and kidneys
- Acidosis: high hydrogen ion concentration (low pH). Can make animals hyperkalemic (potassium driven out of cells).
- Alkalosis: low hydrogen ion concentration (high pH). Can make animals hypokalemic (potassium driven into cells).
- Osmosis: Net movement of water across a semipermeable membrane due to differences in solute concentration
- Normal osmolarity of canine blood: 280-310 mOsm/L
- Osmotic Pressure: Pressure needed to stop movement of water across a semipermeable membrane
- Hydrostatic Pressure: Pressure on fluid not in motion.
- Oncotic Pressure (Colloid Osmotic Pressure): Pressure exerted by large molecules (proteins) in plasma, pulling water into intravascular space. Normal oncotic pressure of plasma is 20-30 mm/Hg.
Tonicity
- Isotonic: Similar to plasma; no fluid shift in cells (0.9% NaCl).
- Hypotonic: Moves IVF to interstitial and intracellular space; cells swell/burst (2.5% Dextrose).
- Hypertonic: Pulls ISF and ICF into intravascular space; cells shrivel (7% Sodium Chloride).
Determining Fluid Needs
- History: Food/water intake, urination/defecation/vomiting, exposure to extreme conditions, fever, current/previous medications.
- Exam: Skin turgor, eye position, body temperature, mucous membrane color/tackiness, pulse rate/strength, CRT, heart rate.
- Lab Tests: Hematocrit & Total Plasma Protein (TPP), Urine Specific Gravity, Serum Chemistry
- Factors Influencing Fluid Loss: Vomiting/diarrhea, increased respiration (panting), diseases with accompanying polyuria, acute or chronic injury, diseases preventing or decreasing oral fluid intake.
Routes of Administration
- Oral: Use only when the GI tract is functioning, for maintenance needs
- Subcutaneous: Choice for small volumes; avoid in dehydrated/hypothermic/hypotensive patients; avoid 5% dextrose solutions
- Intravenous: Used in dehydrated, critically ill, hypovolemic, and metabolic disorder cases; use central venous catheters with hypertonic solutions
- Intraosseous: Used in young or severely debilitated patients; administer through the head of the femur/humerus
Factors That Influence the Rate of Fluid Administration
- Poor Perfusion: Due to dehydration/hypovolemia; needs immediate IV fluid replacement to increase vascular volume; monitor heart, kidneys, and lungs closely. Cannot tolerate rapid fluid infusion. Use CVP monitoring for rate determination.
Contraindications for Fluid Therapy
- Pulmonary edema, pulmonary contusions, existing pulmonary edema, brain injury, congestive heart failure.
Types of Fluid
- Crystalloid Solutions: Electrolyte and non-electrolyte solutions that pass through cell membranes; often used initially in acute blood loss. Examples: Physiologic Saline (0.9% NaCl - isotonic), Lactated Ringer's (LRS), Dextrose in 5% Water, Ringers Solution, Normosol-R, and Normosol-M.
- Colloid Solutions: Large molecular weight particles that are confined to the vascular space and hold fluid; useful for edema and hypovolemia shock. Examples: Dextran 40 and 70, Hetastarch, Plasma, Whole Blood, and 25% Human Serum Albumin (HSA).
Evaluating Volume of Fluids Required
- Maintenance Fluids: Daily intake of water, nutrients, and minerals should match daily loss; daily maintenance = BW (kg) x 60 ml/kg/day; hourly maintenance = 2-4 ml/kg/hr.
- Allometric Scale: Used for calculation of maintenance fluids in dogs & cats.
- Replacement: Percentage of dehydration x body weight (kg) x 1000 ml for acute fluid losses, replaced within 6-8 hours; chronic losses over 24 hours. 1 liter of fluid = loss of approximately 1 kg of body weight (~455 ml fluid loss).
- Clinical Signs of Dehydration: Described by percentage of dehydration.
- Ongoing Losses: Subjective estimate of losses during fluid correction (vomiting, polyuria, diarrhea). Formula is total loss x2.
- Total Fluid Requirements Calculation: Replacement needs + Maintenance + Ongoing losses.
- Fluid Drip Rate Calculation: Volume (mL) x Drip Set (gtt/mL)/Time(minutes).
Indications for Fluid Therapy
-
Dehydration: Loss of TBW with preservation of vascular volume and accompanied by electrolyte loss. Factors: Diarrhea, prolonged vomiting, prolonged fever, sweating, open wounds/burns, lack of access to water, anorexia.
-
Hypovolemia: Insufficient vascular volume to maintain cardiac output during hemorrhage and shock. Rapid re-expansion needed.
-
Diuresis: Increased loss through kidneys, often with renal failure patients and chemotherapy patients.
-
Correcting electrolyte imbalances: Imbalances often due to disease and dehydration.
-
Anesthesia: Fluid administration to maintain blood pressure and facilitate drug dilution/elimination.
Signs of Overhydration
- Restlessness
- Increased respiratory rate
- Increased lung sounds
- Increased blood pressure
- Chemosis: Edematous ocular conjunctiva
Total Parenteral Nutrition (TPN)
- Used when animals are unable to consume food for 3-5 days.
- Fluid therapy done first to rehydrate, electrolyte replace, normalizes acid-base balance.
- Administered via central IV.
Emergency Fluid Rates
- Crystalloids (Dogs: 20-40 ml/kg IV for 15 minutes, then reassess; Cats: 10-20 ml/kg IV for 15 minutes, then reassess); followed by 35-50 ml/kg/hr.
- Colloids (Dogs: 10-20 ml/kg bolus; then 20 ml/kg/day; Cats: 10-15 ml/kg bolus; then 10-15 ml/kg/day.).
- Isotonic crystalloid (shock dose): needed for each 1 ml increase in vascular volume (Dog/Horse: 80-90 ml/kg, Cat: 40-60 ml/kg).
- Hypertonic saline (shock dose): vascular volume increases by 5-10 ml for every 1 ml fluid (Dog: 3-6ml/kg, Cat: 2-4ml/kg).
- Synthetic colloid (shock dose): increase vascular volume by 1-1.5 ml for every 1 ml of fluid (Dog: 20-30 ml/kg, Cat: 10-15 ml/kg).
Anesthetic Fluid Rates
- Maintain blood pressure.
- Port for emergencies.
- Dilution/elimination of drugs more rapidly.
- Anesthetic rate for cats: 3 ml/kg/hr
Antimicrobials
- Can be added to fluids for hospitalized animals.
- Label bags when antimicrobials are added.
- Check for incompatibilities before adding to fluid bags.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
