Nursing Lecture Test 2

Front 1

When is it appropriate to give fluids?

Back 1

1. Severe dehydration, hypovolemia and non-cardiogenic shock
2. Correction of electrolyte imbalances and restoration of acid-base balance to normal.
3. With IV constant rate infusions (CRI's) for drug administration.
4. During surgical procedures.
5. As a mainstay of treatment of many medical diseases including renal insufficiency or failure, pancreatitis, GI disease w/vomiting, addisonian crisis, sepsis and DKA.

Front 2

What do crystalloid solutions consist of?

Back 2

Predominantly water, w/sodium chloride or glucose as the primary component.

Front 3

When are hypotonic, isotonic and hypertonic crystalloids used?

Back 3

Hypotonic - Can be used as a maintenance fluid for those who have a high risk of fluid retention (ex: heart failure)
Isotonic - they are good for maintenance and shock therapy.
Hypertonic - used in very small boluses to increase vascular pressure by drawing fluid from the interstitial and extracellular space. It is used for animals in shock.

Front 4

Isotonic crystalloid solutions that are commonly used are

Back 4

0.9% NaCL (Normal Saline) - fluid of choice for hypercalcemic patients, animals w/metabolic alkalosis and is not recommended for animals w/acidosis.
Lactated Ringers Solution (LRS) & Normosol-R - recommended for acidotic animals. NOT recommended for treating hypercalcemia

Front 5

What are the synthetic colloids?

Back 5

Hetastarch - high molecular weight; stays w/in the vascular space for 12-48 hours.
Dextran - lower molecular weight, but has a larger variation of molecules. It has a shorter duration w/in the vascular space (4-8 hrs), but has greater oncotic pull to the vascular space.

Front 6

What are the natural colloids?

Back 6

Plasma - the ideal colloid to increase oncotic pressure and assist w/hypoproteinemia
Packed Red Blood Cells - contain RBC's only. This is given to animals who have significant RBC anemia and decreased oxygen carrying capacity.

Front 7

What is mild, moderate and severe dehydration?

Back 7

Mild - 5%, tacky mm; slightly slow skin turgor
Moderate - 8%, slow skin turgor; tacky, pale mm; tachycardia; weak pulses; animal may be depressed.
Severe - 10%; all previous signs plus skin loses elasticity; eyes are sunken; signs of hypovolemic shock are present

Front 8

What is the calculation for dehydration fluids?

Back 8

BW (kg) X % dehydration X 1000

Front 9

What is front-end loading?

Back 9

replacing for dehydration over the first 4-8 hours of fluid therapy.

Some clinicians prefer to replace 80% of deficit volume the first day, and the remaining 20% the second day.

Front 10

What is the maintenance fluids calculation?

Back 10

(2-3) mL/kg/hr X BW (weight)

Front 11

What is the replacement fluids calculation?

Back 11

Dehydrated rate + maintenance rate

Front 12

Hypernatremia
(CS, Treatment)

Back 12

1. When sodium concentrations exceed 170 mmol/L, intracellular dehydration results and neurological signs are observed.
2. CS - Lethargy and weakness in the early stages. If untreated, CS will progress to seizures, coma and death.
3. Treatment - Animals should be given 0.9% NaCl. Patients need frequent and seial monitoring and reassessment

NEVER change the sodium level too rapidly b/c you can make them worse rather than better!!!

Front 13

Hyponatremia

Back 13

When Na is lost, the body reacts by decreasing ADH release, causing urine to become more dilute and thereby returning plasma osmolality to normal.

Front 14

What are some causes of Hyponatremia and treatment?

Back 14

1. Hypoadrenocorticism - (Addisons) aldosterone deficiency, which allows sodium loss, volume depletion, ADH release and thirst resulting in hyponatremia.
2. Renal failure - (cats) vomiting causes loss of both sodium and water, polyuria enhances volume depletion and ADH release is stimulated.
3. Treatment - Best choice -> Norm R and then when the sodium starts to rise, switch to 0.9% NaCl - correct slowly!

Front 15

Hyperkalemia
(Causes, CS, Moderate Tx)

Back 15

1. Seen with metabolic acidosis. HR will be very low.
2. Causes - urethral obstruction, rupture of the urinary bladder or ureters, oliguric or anuric renal failure, hypoadrenocorticism, full bladder when HBC. Most common cause is blocked cats.
CS - EKG abnormalities, abdominal pain, diarrhea and flaccid paralysis of the limbs, bradiacardia
Moderate Tx - IV admin of potassium-free fluids and elimination of the factors causing the hyperkalemia.

Front 16

What is the treatment for severe hyperkalemia?

Back 16

1. IV Calcium Gluconate - calcium antagonizes the cardiac effects of hyperkalemia w/o altering the plasma concentration of potassium; protects the heart.
2. IV Dextrose - admin will cause potassium to be shifted back into the cells thru the effects associated w/increased endogenous insulin secretion
3. Regular Insulin - can be co=administered as an IV bolus concurrently w/the dextrose -> drive sugar back into cells

Front 17

Hypokalemia
(Causes, CS, Treatment)

Back 17

1. Causes - can result from inadequate intake, increased excretion thru polyuria or diarrhea or from intracellular translocation of potassium. Ex: anorexia, vomiting, chronic renal failure, diuretic therapy.
***Most critically ill patients on limited oral intake and IV fluid therapy develop hypokalemia and require potassium supplementation.***
2. CS - Subtle or obvious muscle weakness. May manifest as ventroflexion of the neck or a still, stilted gait.
3. Tx - IV supplementation based on CS and serum values and NOT more than 0.5 Meq/kg/hr.
***Oversupplementation can cause fatal cardiac bradycardia.***

Front 18

What are the CS of fluid overload?

Back 18

Serous nasal discharge
SubQ edema
Increased urine output w/normal kidneys
Ascites (fluid accum in abdomen)
Restlessness
Chemosis (Swelling around the conjunctiva)
Exophthalmos (bulging eyes)
Coughing
Increased respiratory rate
Vomiting

Front 19

Dextrose Supplementation Calculation

Back 19

(% Concentration you need X Volume of bag in mL)/% concentration you have = mL to add to bag

Front 20

What are some drugs you may see given as CRI's (Constant Rate of Infusion)?

Back 20

Insulin
Dopamine
Dobutamine
Lasix
Mannitol
Propofol
Lidocaine
Metoclopramide

Front 21

What are the different kinds of shock?

Back 21

1. Hypovolemic Shock - occurs when loss of circulating blood volume causes a severe decrease in tissue perfusion. Almost always caused by hemorrhage or severe dehydration
2. Obstructive Shock - results from a physical obstruction in the circulatory system. HW disease, pericardial effusion, pulmonary embolism and gastric torsion can all impair blood flow.
3. Cardiogenic - results from failure of pump function of the heart. Pump failure may be caused by hypertrophic or dilative cardiomyopathy, valvular insufficiency or stenosis, or arrhythmias.
4. Distributive - This represents relative hypovolemia due to vasodilation and/or increased vascular permeability w/pooling of blood in the peripheral vasculature orloss of fluid into the extravascular space. Causes include sepsis, anaphylaxis and central nervous system/spinal cord injuries.

Front 22

What are the different types of distributive shock?

Back 22

1. Septic shock - a serious, abnormal condition that occurs when an overwhelming infection leads to low blood pressure and low blood flow.
2. Anaphylactic Shock - Tissues in different parts of the body release histamine and other substances. Histamine causes the blood vessels to dilate and fluid to leak from the bloodstream into the tissues, resulting in shock; allergic reaction.
3. Neurogenic Shock - Sometimes called vasogenic shock, results from the disruption of autonomic nervous system control over vasoconstriction.

Front 23

Which type of distributive shock are you likely to see?

Back 23

1. Septic shock - you will see.
2. Anaphylactic Shock - 1-2 times
3. Neurogenic Shock - not often

Front 24

What is the most common type of shock seen in small animal medicine?

Back 24

Hypovolemic shock

Front 25

What are the three stages of shock?

Back 25

1. Stage I (compensated, nonprogressive) - The patient in this stage of shock has very few symptoms, and treatment can completely halt any progression.
2. Stage 2 (decompensated or progressive) - With quick and appropirate treatment, this stage of shock can be reversed.
3. Stage 3 (irreversible) - The endpoint of Stage III shock is the patient's death.

Front 26

What are the physical findings during the initial assessment and recognition of shock (how does the body respond)?

Back 26

1. Tachycardia
2. Decreased pulse quality
3. Prolonged CRT
4. Pale mucous membranes
5. Cool extremities

Front 27

How do you manage Hypovolemic Shock (to restore circulating blod volume and improve oxygen delivery to tissues).

Back 27

1. Control Hemorrhage - if the animal is bleeding, this bleeding must be brought under control
2. Restore Circulating Volume
3. Optimize Oxygen Delivery - airway management and supplemental O2.
4. Sympathomimetics - drugs that increase heart rate, increase heart muscle contraction and increase vascular tone.

Front 28

What are some examples of sympathomimetics and how are they usually given? What should be continually monitored when these drugs are given?

Back 28

1. Dopamine, Norepinephrine, Dobutamine

2. These drugs are usually given as CRI's (Constant Rate of Infusion)

3. Blood pressure should be continually monitored when these drugs are given.

Front 29

What are some ways to restore circulating volume in the mgmt of hypovolemic shock?

Back 29

1. Fluid Resuscitation - venous access is critical when treating hypovolemic patients. A short, large catheter is best if fluids are to be administered. Two peripheral catheters are often placed, to increase the speed w/which fluid resuscitation can be done.
2. Isotonic crystalloids are used to treat hypovolemic shock.
3. Hypertonic crystalloids are recommended for use in shock when it is difficult to administer large volumes of fluids rapidly enough to resuscitate the patient.
4. Colloids - are better blood volume expanders. Examples: Plasma, blood, hetastarch - synthetic

Front 30

Monitoring Shock Patients

Back 30

1. Physical Parameters - RR, RE, auscult for normal breath sounds, HR, ECG, CRT, MM, feel pulses, temperature, urine output
2. Physiologic Monitoring Parameters - Pulse Ox, Arterial Blood Pressure, Urine output monitoring
3. Laboratory Parameters - PCV and TS (tests should be interpreted together), Electrolytes, Blood gases

Front 31

Why should PCV and TS be interpreted together?

Back 31

1. Increase in both PCV and TS indicates dehydration
2. Decrease in both suggests recent blood loss or fluid admin
3. An increased TS w/a normal PCV may indicate anemia w/dehydration

Front 32

What does PaCO2 tell us?

Back 32

How well the patient is ventilating.

Front 33

What does PaO2 tell us?

Back 33

How well the patient is oxygenating.

Front 34

Conclusions of shock

Back 34

1. Shock is a dynamic process. Changes must be observed, evaluated and addressed quickly.
2. The focus of therapy and monitoring is oxygen delivery.
3. Fluid resuscitation, adequate oxygen deliver, vasopressors and careful monitoring all aid in the recovery of animals suffering from shock.
4. Understanding the pathophysiology and compensatory mechanisms associated with shock, will mallow the vet tech to better meet therapeutic needs and monitor the patient.

Front 35

The Conduction System (Heart)

Back 35

1. The heart is a muscle that functions as a pump. It is divided into four chambers - two atria located on the top and two ventricles located on the bottom.
2. The heart beats (contracts) when an electrical impulse from the heart's "natural pacemaker" - the SA node - moves thru it. The normal sequence begins in the right atrium, spreads throughout the atria and to the AV node.
3. From the AV node, the impulses (signals) travel down a group of specialized fibers (the His-Purkinje system) to all parts of the ventricles. This exact route must be followed for the heart to pump properly.
4. As long as the electrical impulse is transmitted normally, the heart pumps and beats at a regular pace.

Front 36

Depolarization and Repolarization

Back 36

1. The firing of the SA node sends electrical impulses thru the atria causing atrial depolarization, creating the P waves on the ECG and triggering atrial contraction.
2. The impulses then travel thru the AV node, bundle of His, right and left bundle branches, Purkinje fibers and ventricular muscle cells, causing ventricular depolarization and creating the Q, R and S waves (QRS Complex) on the ECG and triggering ventricular contraction.
3. The T wave is formed when the ventricles return to their resting state (ventricular repolarization).
***When V is depolar, A is repolar***

Front 37

Atrial depolarization

Back 37

P waves

Front 38

Ventricular depolarization

Back 38

Q, R and S waves

Front 39

Ventricular repolarization

Back 39

T waves

Front 40

Define systole

Back 40

When the heart contracts and blood in pumped away

Front 41

Define diastole

Back 41

when the heart relaxes and the ventricle fills w/blood

Front 42

Define Preload

Back 42

How much blood is contained in the ventricle just before it contracts

Front 43

Define Afterload

Back 43

the force that resists the flow of blood leaving the heart (for ex - blood would flow more easily into a dilated artery than a constricted arter)

Front 44

Define Contractility

Back 44

how effectively the heart muscle contracts

Front 45

Define Stroke Volume

Back 45

amount of blood pumped with each beat of the heart

Preload, afterload and contractility are the three factors that determine stroke volume.

Front 46

Define Cardiac Output

Back 46

Total volume of blood pumped by the heart in one minute (amount of blood ejected from 1 ventricle in 1 minute)

Cardiac Output = Stroke Volume X HR

Front 47

Types of Heart Failure

Back 47

1. Low-Output (Forward Failure) - occurs when the heart cannot pump enough oxygenated blood to the tissues. Severe low-output failure, especially when accompanied by hypotension, is called cardiogenic shock.
2. Congestive (Backward Failure) - back up in either left or right side of the heart

Front 48

Example of Low-Output Heart Failure (Forward Failure)

Back 48

Ex: dilated cardiomyopathy -> mancoon is known for this - heart gets really big, doesn't contract well

Front 49

Right Heart Failure

Back 49

The right heart consists of the right atrium which receives deoxygenated blood from the body and the right ventricle which pumps it to the lungs. If the right heart fails, fluid backs up in the abdomen or space surrounding the lungs

Body -> RH Fails -> Fluid -> Body

Front 50

Left Heart Failure

Back 50

the left heart consists of the left atrium which receives oxygenated blood from the lung and the left ventricle which pumps it out to the body under high pressure. If the left heart fails, fluid backs up into the lungs.

Lungs -> LH fails -> Fluid -> Lungs

Front 51

What is Hypertrophic Cardiomyopathy (HCM)? (CS, dx, tx)

Back 51

a disease (common in cats) that causes thickening of the heart muscle resulting in poor relaxing and filling ability.

CS - Some pets show no sign of illness, esp early in the disease. In other cases, signs of left-sided congestive heart failure may occur. Signs include lethargy, decreased activity level, rapid and/or labored breathing and poss open mouth breathing w/excitement or exercise.

Dx - Radiographs, ECG, echocardiagram (heart ultrasound)

Tx - Beta-blockers or calcium channel blockers (emlodipine, diltiazem) - these drugs decrease HR so that the heart can fill more efficiently.

Front 52

What is Saddle Thrombus (Feline Aortic Thromboembolism)? (CS, Tx)

Back 52

Thrombi develop in the heart, usually in the left atrium, and then travel into the systemic arteries. These usually lodge in the distal aorta, where they often cause posterior paresis, paralysis and pain.

High mortality

CS - hind limb paralysis, pain, cold rear leg, no femoral pulses, cats are often "yowling" on presentation, may have dyspnea and tachypnea

Tx - Medical mgmt, pain relief - morphine, heparin and/or warfarin, baby aspirin, TPA (tissue plasminogen activator) or streptokinase - these are "clot busters", surgical removal of clots - very high mortality - called an embolectomy, not done much anymore.

50% will have a recurrence w/in 9 months

Front 53

What is Pericardial Effusion? (CS, dx, tx)

Back 53

Dogs

Neoplasia and idiopathic are two of the most common causes of pericardial effusion and generally produce signs of right heart failure (cancer too).

CS - weakness or collapse, weak pulses and muffled heart sounds

Dx - radiographs, ultrasound

Tx - Fluid load them and then ta them, fluid is bloody in appearance, idiopathic - after tx, 50-60% will not recur

Front 54

What is Dilated Cardiomyopathy (DCM)? (CS, tx)

Back 54

A disease of the heart muscle which causes the heart to enlarge and not function properly. Usually afflicts larger breeds of dogs such as the doberman, boxer, newfoundland, golden/labrador retriever, irish wolfhound.

Occurrence increases w/age - typical onset between 4-10 yrs

Cause is still unknown, but suggest genetic cause

CS - Cough, weakness, dyspnea, exercise intolerance

Tx - Lasix and in O2 first, then dobutamine (to increase contractility) and nitroprusside (vasodilator).

Front 55

What is Congestive Heart Failure in dogs?

Back 55

Left-sided CS - respiratory distress - shortness of breath and coughing.

Right-sided CS - Ascites, fluid build-up in the abdomen, causing pot-bellied appearance

Both - weight loss can be seen, as well as decreased appetite.

Front 56

Diuretic therapy

Back 56

Emergency Tx of Heart Failure

Lasix is a potent antidiuretic that can be used to eliminate fluid from the body quickly. It is a very effective emergency tx for life-threatening pulmonary edema caused by congestive heart failure.

Front 57

Oxygen therapy

Back 57

Emergency tx of heart failure

CHF often causes ypoxia and hypoventilation thru hydrothorax and pulmonary edema. Oxygen therapy can improve oxygenation and reduce the work of breathing. B/c these animals are often very stressed, an oxygen cage is effective for initial oxygen support

Front 58

Vasodilators

Back 58

Emergency tx of heart failure

Vasodilating drugs are effective in treating both congestive and low-output heart failure

Front 59

Antiarrhythmics drugs

Back 59

1. Diltiazem, Verapamil - calcium channel blocker. Combat arrhythmias by blocking Ca+ channels of cardiac muscle cells. Most commonly used in cats w/HCM to promote heart muscle relaxation.

2. Atenolol, Propanolol - beta-blockers slow the heart rate, reduce the heart's demand for oxygen and control certain arrhythmias. They cause the heart to contract w/less force.

3. Lidocaine - Controls PCV's and ventricular arrhythmias. Reduces arrhythmias primarily by decreasing the rate of Na+ movement into the cell

4. Procainomide - used to control arrhythmias, particularly atrial fibrillation and atrial flutter

Front 60

Vasodilator drugs

Back 60

1. Enalapril - ACE inhibitos dilate blood vessels, and reduce resistance in the blood vessels to reduce work load on the heart. Will cause hypotension.

2. Nitroglycerin - prescribed to help reduce congestion by dilating veins. It is supplied as an ointment that is applied to the skin. Gloves should be worn as it is absorbed thru the skin

Front 61

Diuretic drugs

Back 61

Furosemide - (Lasix) used to promote the loss of excess fluid in patients w/congestive heart failure. Adverse effects of furosemide are usually related to excessive fluid and/or electrolyte losses, resulting in dehydration and weakness.