Ch 5 Fluids

Question 1

what are % total body water Int’s and extracellular compartnebts?

Answer 1

Water constitutes approximately 60% of body weight

Question 2

Na+-K+/ATPase;

Which direction Intra/extracell,
Which high, low intracellular?

Answer 2

Na+ OUT
K+ IN
to the cell, consuming adenosine triphosphate (ATP)

Na+ concentration is very high in the extracellular fluid and very low in the intracellular fluid, and K+ is very high in the intracellular fluid and very low in the extracellular fluid

Question 3

Movement of fluid from the intravascular to extravascular (interstitial and intracellular) space occurs at the level of the capillary.

Answer 3

endothelial barrier is a layer of glycoproteins and proteoglycans produced by the endothelium called the glycocalyx.

Question 4

reabsorption of fluid requires what intravascular pressure?

Answer 4

increased intravascular oncotic pressure or decreased intravascular hydrostatic pressure

Question 5

fluid filtration

Answer 5

decreased intravascular oncotic pressure or increased intravascular hydrostatic pressure

Question 6

What is Oncotic pressure ?

Hydrostatic pressure?

Answer 6

osmotic pressure
(globulins, fibrinogen, and albumin)

intravascular blood pressures and vascular resistance.

Question 7

increased fluid losses (hypotonic, isotonic, and/or hypertonic) and decreased intake may lead to dehydration

losses can also result in decreased effective circulating volume

Answer 7

losses can also result in decreased effective circulating volume

Question 8

5-12% dehydration signs

Answer 8

Question 9

how calculate fluid required

Answer 9

Question 10

Treatment of shock

Important to deliver what to tissue?
Normalises what to ensure tissue perfusion? (5)

requires restoration of organ perfusion

Answer 10

Oxygen delivery to tissue DO2

Normalization:
- intravascular volume
- preload
- MAP
- cardiac output
- oxygen content
are crucial in supporting tissue perfusion

Question 11

Oxygen is essential for the electron transport chain, a crucial step in oxidative phosphorylation that generates ATP.

shock > decrease in production of ATP. This energy deficit compromises the function of the Na+-K+/ATPase membrane pumps and causes

Answer 11

disruption of the cell membrane

exposure of subendothelial > activation of the platelets, clotting cascade

bacterial translocation in the intestinal tract.

SIRS, sepsis, and multiple organ dysfunction commonly result.

Question 12

Perioperative Fluid Therapy

anesthetic drugs commonly have negative effects on the heart, blood pressure, and baroreceptor response

Answer 12

Tissue ischemia can interfere with wound healing and normal tissue defenses

dogs 5 mL/kg/h of crystalloids and cats started at 3 mL/kg/h

Close monitoring of the animal’s vital signs, blood pressure, and pulse oximetry reading

Question 13

(goal-directed) approach for resuscitation
Aim to achieve (5)?

Answer 13

aimed to achieve:
- central venous pressure >8 to 12 mm Hg
- mean arterial pressure >65 mm Hg
- urine output >0.5 mL/kg/h
- arterial oxygen saturation [SaO2] >93%
- hematocrit >30%) within 6 hours.

Question 14

Fluid/product types and uses (5) for shock

Answer 14

Isotonic crystalloids
(replacement fluids) are electrolyte-containing fluids with a composition similar to that of extracellular fluid

“Maintenance” crystalloid
hypotonic and contain less sodium

hypertonic crystalloids,

synthetic colloids

blood products

Question 15

isotonic crystalloid

Answer 15

used to expand the intravascular and interstitial spaces and to maintain hydration

extracellular-expanding fluids,” and 75% of the volume redistributed to interstitial space

NaCl, LRS, Plasmalyte

Question 16

Excessive fluid administration

Answer 16

lead to
interstitial edema, pulmonary edema, and cerebral edema, all of which will decrease oxygen delivery and organ function.

increased risk:
low colloid osmotic pressure, pulmonary contusions, cerebral trauma, renal disease, or cardiac disease, substantial hemodilution of red blood cells, plasma proteins, clotting factors, and platelets can occur.

Question 17

Surgical patients with head trauma
- Periop patients with severe hypoNa or hyperNa
- Surgical patients with hypoCl metabolic alkalosis
- Surgical patints with severe metabolic acidosis, not due to lactate

Answer 17

Head trauma –> 0.9%NaCl. Has the highest Na conc and therefore is least likely to cause a drop in osmolality and cerebral oedema
Hypo/hyperNa –> Choose the fluid which most closely matches their Na. Too rapid a drop can cause cerebral oedema. To rapid an increase can cause central pontine myelinolysis
HypoCl met alkalosis –> 0.9%NaCl as it is the highest in Cl and will help normalise the pH
Metabolic acidosis –> Crystallois with a buffer (lactate, acetate, gluconate). NOT NaCl

Question 18

hypotonic fluids

maintenance fluids

Answer 18

0.45% NaCl
0.45%NaCl with 2.5% dextrose
Plastalyte 56
Plasmalyte M with 5% dextrose
Normosol M with 5% dextrose
5% Dextrose in water (D5W)
Dextrose is rapidly metabolised to H2O and CO2 (good source of free water)

Maintenance fluids low in sodium, chloride, and osmolarity

Question 19

hypotonic fluids

maintenance fluids

Answer 19

Contraindicated as bolus therapy in animals with hypovolemia

Large volumes can lead to a rapid decrease in osmolarity and subsequent cerebral edema

Question 20

Hypertonic (7.0% to 7.5%) sodium chlorid

Answer 20

transient osmotic shift of water from the extravascular to the intravascular

4 to 6 mL/kg over 10 to 20 minute,
transient (<30 minutes),.

Rates exceeding 1 mL/kg/min leads to vagally mediated hypotension, bradycardia, and bronchoconstriction and should be avoided

treatment of head trauma or cardiovascular shock in animals >30 kg

Question 21

Synthetic colloid solutions

0.5 to 2 mL/kg/day.

total dose of <20 mL/kg/day is advised to avoid side effects.

treatment of ? (2)

Answer 21

carge molecules (molecular weight >20,000 daltons

increase the colloid osmotic pressure of the plasma > pull fluid into the intravascular space.

colloid particles help to retain this fluid in the intravascular space in the animal with normal capillary permeability

Treats: shock and hypoproteinemia

Question 22

What are potential side effects of colloids? (4)

Hydroxyethyl starches

Answer 22

Disruption of normal coagulation
(depletion of VIII and vWB),
impaired platelet function,
interference of stability of fibrin clots

Anaphylaxis

Volume Overload

Renal impariment

difficult to predict which animals will develop clinical bleeding

Question 23

low colloid osmotic pressure

negatively affect wound healing

predispose to bacterial translocation from GIT into the bloodstream.

Answer 23

low oncotic pressure

lead to interstitial edema

decreased tissue perfusion

increased distance for the diffusion of oxygen and nutrients.

Question 24

Hemoglobin-Based Oxygen-Carrying Fluids

Oxyglobin

Answer 24

sterile, ultrapurified, stroma-free, polymerized bovine hemoglobin solution.
nonantigenic (typing or cross-matching not required)

an cause marked vasoconstriction through its nitric oxide–scavenging effect

Question 25

Q How much blood loss requires a transfusion?

Answer 25

Can usually tolerate 10-15% blood loss but 20% often requires transfusion hematocrit target may be increased to >30% to maximize oxygen-carrying capacity. elective sx > donate blood in advance to have autologous blood available

Question 26

blood loss requiring transfusion

Answer 26

fresh whole blood packed red blood cells fresh frozen plasma autotransfusion

Question 27

Whole blood

Answer 27

All of the components present in blood. clotting factors and platelets, but platelets are best administered within 8 hours

Question 28

Packed red blood cells

Answer 28

typically have a hematocrit of approximately 80%. When stored at 4°C, the standard shelf life is 20 days, no clotting factors or platelets ready availability, low risk for volume overload, and reduced exposure to plasma antigens

Question 29

Plasma | Animals with vWD

Answer 29

clotting factors but also proteins, albumin, and globulins Fresh frozen plasma is defined as plasma that is frozen within 6 hours profound blood loss, a coagulopathy, or severe hypoalbuminemia. The ability of plasma products to increase colloid osmotic pressure is limited dministered through a filter over at least 1 to 2 hours to monitor for a transfusion reaction and avoid volume overload, thrombocytopenia or thrombocytopathia may require platelet-rich transfusion products

Question 30

blood types

Answer 30

blood donors should be dog erythrocyte antigen 1 and 7 negative if possible. In vitro cross-matching is also recommended if time allows. feline are known: A and B. ype B cats do often have strong naturally occurring anti-A antibodies. Administration through a microfilter with 170-µm pores is commonly used to remove clots and larger red cell and platelet aggregate

Question 31

reaction (both immune-mediated and non–immune-mediated reactions), | patients should be monitored closely

Answer 31

Transfusion-associated circulatory overload (TACO) nonhemolytic febrile reactions (1C within 30-60min) Transfusion-related acute lung injury (TRALI) igns of a transfusion reaction include fever, restlessness, vomiting or diarrhea, acute collapse, wheezing, dyspnea, urticaria, hemoglobinemia or hemoglobinuria, and/or hypotension.

Question 32

autotransfusion of whole blood | ministered through a blood filter to the patient.

Answer 32

recent (<24 hours), large-volume hemorrhage into the pleural or peritoneal cavity, not a dependable source of clotting factors because depletion of fibrin possible inflammatory response syndromes Hemorrhage due to neoplastic or septic processes should not be autotransfused to prevent systemic circulation of these pathologic cells and organisms.

Question 33

Administration of 25% human albumin

Question 34

Sodium | primary extracellular cation

Answer 34

Na-K ATP pump regulated by free water balance. Vasopressin (antidiuretic hormone) release and thirst are the primary mechanisms responsible for free water balance Renal sodium retention or excretion regulates extracellular fluid volume > releasing renin, which ultimately results in increased serum aldosterone levels (via RAAS) | aldosterone > reabsorption of Na and H2O

Question 35

Causes of Hyponatremia CS: depression, ataxia, coma, seizures secondary to cerebral edema | less than 140 mEq/L

Answer 35

* Hypervolemia heart failure liver disease kidney failure / nephrotic syndrome * Normovolemia Psychogenic polydipsia Antidiuretic drugs * Hypovolemia Gastrointestinal loss (V+/D+) Third-spacing loss Peritonitis Uroabdomen Burns Hypoadrenocorticism | Tx: slowly, no more quickly than 0.5 mEq/L/h

Question 36

Hypernatremia CS: due to rapid increase, CNS signs | greater than 150 mEq/L

Answer 36

Hypovolemic * Gastrointestinal loss (V+/D+, obstructions) * Third-spacing loss (Peritonitis) Burns Renal failure Diabetes mellitus Postobstructive diuresis Normovolemic Hypernatremia * Diabetes insipidus * Inadequate water intake Hypervolemia * Excessive salt ingestion * Hypertonic fluid administration * Hyperadrenocorticism * Hyperaldosteronism | slowly to prevent cerebral edema, Tx isotonic crystallaoid 0.5meq/l/h

Question 37

Potassium | major intracellular cation

Answer 37

critical to cell resting membrane potential and neuromuscular transmission, particularly in excitable muscle and cardiac cells. potassium moves down the concentration gradient across the cell membrane negative charge inside the cell relative to the outside = resting membrane potential −90 mV. balance > function of intake through the GIT, excretion via the kidneys (aldosterone) | outside > inside: glucose, insulin, catecholamines, metabolic alkaloses

Question 38

Hypokalaemia CS: muscle weakness, cardiac arrhythmias, cervical flexion and pelvic limb weakness | less than 5.0 mEq/L

Answer 38

Decreased Intake diet fluids Increased Loss Chronic renal failure Postobstructive diuresis Loop diuretics * Mineralocorticoid excess Hyperadrenocorticism Hyperaldosteronism * GIT loss V+ gastric contents Diarrhea Translocation Into Intracellular * Alkalemia * Insulin * Glucose | Tx: correct underlying disorder and supplementation K+, 0.5mEq/kg/hr

Question 39

Hyperkalaemia CS: dysrythmia dt resting membrane potential chnage of cardiac myocytes bradycardia, wide QRS, peaked T- wave TX: potassium-deficient fluids. Calcium gluconate (10%) 0.5 to 1 mL/kg over 10 to 20 minutes (TO ALTER CARDIAC MYOCYTE POTENITAL) dextrose 0.5 to 1 g/kg with or without insulin 0.5 to 1 IU/kg (IV or IM) (DRIVE INTRACELLULAR) peritoneal dialysis | greater than 5 mEq/L

Answer 39

Decreased Urinary Excretion * Urethral or bilateral ureteral obstruction * Uroabdomen * renal failure * Hypoadrenocorticism * Chylothorax with repeated thoracocentesis * Drugs Potassium-sparing diuretics Heparin * Translocation metabolic acidosis Tissue trauma * Insulin deficiency Increased Intake * Iatrogenic Pseudohyperkalemia * Thrombocytosis * Marked elevations WBC | Tx: underlying cause + Ca + glucose/insluin

Question 40

Calcium

Answer 40

roles in neural excitability, muscle contraction, and blood coagulation. 99% bone, 1+ intra.extracell ionized (active form), protein bound, and chelated. Three hormones: parathyroid hormone, vitamin D (cholecalciferol), and calcitonin. act at the kidney, intestine, and bone to regulate calcium balance. Calcitonin inhibit bone resorption

Question 41

Hypocalcaemia CS: tremors, restlessness, facial rubbing, seizures, ataxia, inappetence, vomiting, | ionised lower than 5.0 mg/dL (1.2 mmol/L)

Answer 41

Decreased PTH 1 or 2nd hypoparathyroidism Post thyroidectomy Post parathyroidectomy renal failure * Nutritional 2nd hyperparathyroidism * Malabsorptive syndromes * Urinary tract obstruction * Ethylene glycol toxicosis * Peritonitis/sepsis Hypoalbuminemia (Will Decrease Total Calcium but Not Ionized Calcium) | Tx: 10% calcium gluconate (0.5-1.5 mL/kg IV), monitor 4 bradycardia

Question 42

Hypercalcaemia CS: CNS (depression,lethargy, seizures) weakness, decreased tendon reflexes PUPD, vomiting, and anorexia cardiac (short QT, prolonged PR, wide QRS) | ionized calcium 1.5 mmol/L dogs and 1.4 mmol/L cats.

Answer 42

HARDIONS Hyperparathyroidism Addisons Renal Failure Hypervitaminosis D iatrogenic Osteolytic Neoplasia (Lymphosarcoma, OSA, AGASACA, mammary) Spurious | Tx: cause, IVFT,frusemide, CCS, calcitonin, diet

Question 43

Glucose

Answer 43

principal substrate for energy in the brain beta cells (pancreas) secrete insulin, movement of glucose into the cell stored as glycogen or fat. liver converts glycogen into glucose via glycogenolysis forms glucose from lactate and amino acids via gluconeogenesis Glucagon (alpha pancreatic cells) stimulates glycogenolysis and the release of glucose

Question 44

Hypoglycemia Whipple's triad (low blood glucose with concurrent clinical signs > resolution when level is normalized) CS: mental depression, syncope, ataxia, blindness, seizures, or coma | less than 3.3 mmol/l

Answer 44

* Insulin overdose * Insulinoma * Paraneoplastic syndrome (hepatocellular carcinoma, Pulmonary, mammary, Lymphoma) * Toxins and medications Excess Glucose Utilization (Infection, pregnancy, polycythaemia) * Neonatal * Hepatic dysfunction (PSS) * Hypocortisolism | Tx: dextrose (0.5 g/kg) bolus, CRI 2.5% to 5% dextrose ## Footnote insulin-like peptides, increased glucose utilization by the neoplasm

Question 45

hyperglycaemia | > 10 mmol/l

Answer 45

Postprandial * Diabetes mellitus * Pancreatitis * Glucocorticoids Stress Hyperadrenocorticism Exogenous steroids * Catecholamines Pheochromocytoma * Growth hormone–secreting neoplasms * Glucose- or dextrose-containing fluids | Tx: short-acting insulin 0.1 - 0.25 unit/kg IM or CRI 1.1- 2.2 units/kg

Question 46

Acid-BAse

Answer 46

buffers play an important role in acid-base homeostasis in the body bicarbonate, proteins, and phosphate regulation of PaCO2 through alveolar ventilation in the lungs and maintenance of normal [HCO3−] in the extracellular fluid by the kidneys chemoreceptors that sense changes in blood pH 95% of filtered HCO3− is reabsorbed in the proximal tubule

Question 47

base excess + ANion gap | −4 to +4 mEq/L

Answer 47

assess the metabolic component of acid-base disturbances. negative = nonrespiratory acidosis, and positive = nonrespiratory alkalosis. Electrolyte derangements are often the first sign of an acid-base disorder electroneutrality. increased anion gap acidoses include ketoacidosis, lactic acidosis, ethylene glycol toxicosis, salicylate toxicosis, and uremic states. in dogs 11 to 26 mEq/L, and in cats 13 to 27 mEq/L.

Question 48

metabolic acidosis, metabolic alkalosis, respiratory acidosis, and respiratory alkalosis

Answer 48

Primary disorders are accompanied by secondary adaptive compensation by the opposing system of acid-base regulation.

Question 49

Respiratory Acidosis hypoventilation causes hypercapnia | increase blood PaCO2 + decreased pH

Answer 49

Hypoventilation due to neuromuscular or structural/airway conditions   Central respiratory depression   Drugs (eg, opioids)   Brain disease   Cervical spinal cord injury   Neuromuscular disease   Respiratory muscle fatigue   Airway obstruction Anesthetized patient   Increased inspired CO2   Increased apparatus dead space   Malignant hyperthermia | Tx: correct underlying and improve ventilation

Question 50

Respiratory Alkalosis when hyperventilation results in hypocapnia | low PaCO2 with an elevated pH

Answer 50

brain disease Drugs Sepsis Pulmonary disease   Pain, anxiety, stress Low CO > Hypovolemic shock | no specific therapy

Question 51

Metabolic Acidosis loss of HCO3− via the kidney or gastrointestinal tract or increase in nonvolatile acids | low [HCO3−] with a low pH

Answer 51

Bicarbonate loss (hyperchloremic)   Renal tubular acidosis   Intestinal loss   Saline administration Acid gain (Increased anion gap) D—Diabetic ketoacidosis U—Uremia E—Ethylene glycol toxicity L—Lactic acidosis | Tx: underlying, Sodium bicarbonate

Question 52

bicarbonate therapy, adverse effects

Answer 52

hypernatremia, hypervolemia, ionized hypocalcemia, hypokalemia, and respiratory acidosis

Question 53

Metabolic Alkalosis gain of bicarbonate or the loss of acid | increased [HCO3] and increased pH

Answer 53

Bicarbonate gain sodium bicarbonate admin Acetate, citrate Acid loss  Vomiting with proximal GIT obstruction   Nasogastric tube suctioning   Renal acid loss | tx: underlying, fluid and electrolyte (hypokalemia and hypochloremia)