Blood Vessels Practice Questions

Blood flow through a capillary bed is regulated by precapillary sphincters.

Large veins, medium veins, and venules have valves to prevent the backflow of blood.

Increased capillary filtration, reduced reabsorption, or obstruction of lymphatic drainage can lead to edema.

The pulmonary circuit is the only route in which arteries carry less oxygen than veins.

The three primary branches of the celiac trunk are the common hepatic, left gastric, and splenic veins.

Blood filtered through the hepatic sinusoids exits the liver via the hepatic veins.

Arterial flow to the lower limb comes from the external iliac artery.

The brachial vein is the most common site of blood pressure measurement with the sphygmomanometer.

The radial artery is lateral to the ulnar artery.

Which vessels have the thickest tunica media?
Large arteries

Where is the greatest volume of blood found in the body?

Alternative routes of blood supply are called __________.

Which of the following is not a possible circulatory route from the heart?
Heart → arteries → capillary bed → vein → capillary bed → arteries → heart

In people who stand for long periods, blood tends to pool in the lower limbs and this may result in varicose veins. What causes the varicose veins?
Failure of the venous valves

Which of the following does not move substances across capillary walls?
Group transport

What is the most important force driving filtration at the arterial end of a capillary?
Blood hydrostatic pressure

What is taken up by the capillaries at their venous end?
Waste products

What is the most important force driving reabsorption at the venous end of a capillary?
Blood colloid osmotic pressure

How many pulmonary arteries empty into the right atrium of the heart?

Which of the following is absent in humans?
Right and left brachiocephalic arteries

Which vessel supplies 80% of the cerebrum?
Internal carotid artery

Which of the following best describes the cerebral arterial circle (circle of Willis)?
An anastomosis surrounding the pituitary gland

What are the major branches of the abdominal aorta from superior to inferior?
Celiac trunk, superior mesenteric artery, renal arteries, gonadal arteries, inferior mesenteric artery, and common iliac arteries

What is the longest vein commonly used in grafts in coronary bypass surgery?
Great saphenous vein

What is the path of blood flow from the heart to the lung tissues and back to the heart?
Right ventricle – pulmonary trunk – pulmonary arteries – lung tissues – pulmonary veins – left atrium

Anesthesia for Veterinary Technicians (Bryant) – Chapter 12: Fluid Therapy and Blood Products

Water weight
Roughly 60% of the patien’s body weight is water. Of the 60%, 66.6% is intracellular and 33.3% is extracellular.

Intracellular compartment
The space within a cell membrane. Contains 66.6% of the patient’s water weight (~40% of the patient’s body weight).

Extracellular compartment
Contains 33.3% of the patient’s water weight (~20% of the patient’s body weight. Composed of 25% intravascular water and 75% interstitial water.

Intravascular fluid
Contained within the arteries, veins, and capillaries.

Interstitial fluid
Found in the extravascular space between vasculature and cells.

The sites of fluid exchange between the intravascular and interstitial spaces. The size of the solute will determine how freely it can move across membranes,

Transcellular fluid
Includes cerebrospinal fluid, gastrointestinal fluid, lymph, bile, glandular and respiratory secretions, and synovial fluid. Not a transudate from plasma (should have a higher protein and cell count). Produced through specific cell actions. Not taken into account when assessing extracellular fluid volume.

Comprises less than 1% of free fluid in normal tissues. Uses kinetic motion to diffuse solutes.

Interstitial edema
Occurs when the lymphatic system is overwhelmed. A result of a decrease in oncotic pressure and an increase in hydrostatic pressure. Can occur due to shock, illness, or trauma. The capillary endothelial junctions can become separated when previously hypoxic tissues become reperfused. Albumin and fluids then leak out of the intravascular space. This leads to hypovolemia and can then lead to a decrease in oxygen transport and therefore a decrease in oxygen diffusion to cells.

Any solutions that contain electrolyte and non-electrolyte solutes. Enter all body fluid compartments but have heir main effect on the interstitial and intracellular spaces. Can be further broken down into isotonic, hypertonic, or hypotonic preparations. Can also be classified as balanced or unbalanced solutions. Used to expand the plasma compartment, rapidly redistributes to the intracellular and interstitial spaces, so 2.5-3 times as much must be given (compared to colloid).

Isotonic fluids
Normosol-R and Plasmalyte 148, 0.9% NaCl, LRS. Have a similar sodium and chloride concentration and a higher potassium concentration to that of extracellular fluid, as well as a similar osmality. Rapidly equilibrate across the intravascular and interstitial spaces, therefore only 25% of the total volume administered stays within the intravascular space.

hypotonic solutions
0.45% NaCl, 5% Dextrose, Normosol-M, and Plasma-Lyte 56. Have a lower sodium and chloride content and a higher potassium content.

hypertonic solutions
3% NaCl, 7.2% NaCl, or 23.7% NaCl. Have a much higher sodium and chloride content than extracellular fluid.

Balanced crystalloids
Have a fluid composition that closely resembles extracellular fluid. LRS, Normosol-R, and Plasma-lyte 148.

Unbalanced crystalloids
Do not have a fluid composition that resembles the patient’s extracellular fluid. Normal/physiologic saline (0.9% NaCl)

Contain large molecular weight substances that will stay within the plasma compartment. Predominantly used as expander of the intravascular space. Can be natural or synthetic.

Natural colloids
Plasma, whole blood, and concentrated albumin

Synthetic colloids
Dextrans, hetastarch, vetstarch, pentastarchm and HBOC fluids.

The predominant plasma protein, pooled from human donors. Available in both a 4% and a 25% preparation. 25% is most widely used in clinical settings. Vascular expansion depends on the amount given, not on solution concentration. Main drawback is cost. Can cause fluid-overload.

Hydroxyethyl starch. A plasma volume expander and will give equivalent plasma volume expansion to that of 4% albumin. Lower cost, can induce coagulopathies when the recommended dosages have been exceeded. In dogs, dosed at 10-40mL/kg/day IV to effect. In cats, the dose is 5mL/kg IV to effect, with a maximum dose I’d 40mL/kg/day. 20mL/kg/day maximum is usually sufficient. Take care to avoid fluid overload.

Come as either 40 (a 10% solution) or 70 (a 6% solution). Made from a glucose polymer that is produced by bacteria grown on sucrose media. Produce an initial but temporary intravascular volume expansion. 50% of the expansion is lost within 3 hours, and 60% is lost within 6 hours. Dosed at 10-40mL/kg/day in dogs. In cats the dose is 5mL/kg IV over 5-10 minutes, and it can be reposed as needed, not to exceed 40mL/kg/day. Must be used cautiously. Can cause renal issues and have a dramatic affect on coagulopathies.

Fluid therapy
Meant to be supportive. Occurs in three phases: resuscitation, rehydration, or maintenance.

Maintenance fluid therapy
Administered at a rate of 40-60mL/kg/day. Designed to meet water and electrolyte requirements for patients not taking in enough fluids to meet their daily losses. Should be isotonic. Can use hypotonic solutions for renal patients, patients with CHF or hypernatremia, and patients on potassium bromide therapy.

Insensible losses
Occur through the skin, fecal waste, and the respiratory tract.

Sensible losses
Should occur as urine output

Potassium chloride. Long-term Therapy of any kind may cause a hypokalemia by evoking diuresis. Therefore, fluids should be supplemented with potassium chloride at 20mEq/L. Don’t bolus. Maximum rate of administration should not exceed 0.5mEq/kg/hr.

Isotonic saline
Used for rapid expansion of the extracellular fluid volume and is quickly redistributed through the extracellular space. Can be used as a replacement fluid but does not meet the patient’s daily electrolyte requirements when used as a maintenance fluid. Can have an acidifying effect because of its high chloride content and should be used cautiously in acidemic patients.

Replacement fluid therapy
Should be isotonic and contain a balanced electrolyte solution. They can be given as a bolus without causing electrolyte abnormalities. Only 25% of the total volume administered of crystalloids will stay in the intravascular spaceIf replacing blood loss with crystalloids alone, three times the volume of blood lost must be given. If replacing losses due to dehydration, the percent of dehydration should be calculated first.

<5% Dehydration
Not detectable

5-6% Dehydration
Subtle loss of skin elasticity

6-8% Dehydration
Definite delay in return of skin to normal position, slight prolongation of CRT, eyes possibly sunken in orbits, possibly dry mucous membranes

10-12% Dehydration
Tented skin stands in place, definite prolongation of CRT, eyes sunken in orbits, dry mucous membranes, possible signs of shock (tachycardia, cool extremities, rapid and weak pulses)

12-15% Dehydration
Definite signs of shock, death imminent

Hydration deficit (replacement requirement)
a. Body weight (lbs) x % dehydration as a decimal x 500* = deficit in mL
b. Body weight (kg) x % dehydration as a decimal = deficit in L
(*500mL = 1lb)

Resucutation fluid therapy
Determined by a patients clinical history and physical exam findings. Used to treat shock.

Signs of shock
Pale mucous membranes, a prolonged to absent CRT, tachycardia or severe bradycardia, cool extremities, weak to absent peripheral pulses, and hypotension.

Can result due to a lope of blood sample, vomiting of stomach contents, chronic respiratory acidosis, hyoeradrenocorticism, exercise, or sodium bicarbonate therapy. Can be caused by loop diuretics (furosemide).

Can be the result of a life if blood sample, potassium bromide therapy (analyzer reads bromide as chloride), high chloride-containing fluids, diarrhea, or an overall gain of chloride due to potassium supplementation or salt poisoning. Renal chloride retention can occur as a result of renal failure, hypoadrenocortisism, diabetes mellitus, chronic respiratory alkalosis, or spiromolactone drug therapy.

Na+. A major extracellular cation. Serum concentration tells the amount of Na+ compared to water in the extracellular fluid.

Sodium less than 140mEq/L in canines and 149mEq/L in felines. Will result when a patient is unable to excrete ingested water or when its urinary and insensible losses have a greater osmolality than that of the ingested or administered fluids. Neurological symptoms caused by cerebral edema. Acute onset can be treated with LRS, normal saline, or hypertonic fluid.

When sodium is greater than 155mEq/L in dogs and 162mEq/L in cats. Can result from an inadequate intake of water, an excessive amount of sodium ingested or administered, a pure water deficit, hypotonic loss, or hemorrhagic shock. In case of pure water deficit, treatment is 5% dextrose or 0.45% NaCl (hypotonic solutions). Neurological symptoms seen due to a rapid decrease in brain volume caused by rupture of cerebral vessels or focal hemorrhage.

Sodium imbalances
Clinical signs are the same for hyponatremia and hypernatremia. The severity of signs is related to the rapidity of onset, not to the magnitude of imbalances. Neurologic signs include weakness, behavioral changes, disorientation, ataxia, seizures, coma, and death. Other signs include anorexia, lethargy, and vomiting. Levels should not be changed any more rapidly than 10-12mEq/L in 24 hours (0.5mEq/L/hr) for fear of causing neurologic effects that are trying to be avoided.

Fluid calculation for sodium correction
Rate of Na+ Change = (Na+ of the fluid – Na+ of the patient) / (0.6 x BW in kg) + 1
For example:
Patient Na+ = 190mEq/L, wt. 20kg, LRS (Na+ 130mEq/L), fluid rate 100mL/hr
130 – 190 /(0.6 x 20) + 1 = 4.6mEq/L
Safe fluid choice and rate. A liter bag would last 10 hours and the Na+ can safely be adjusted by 5mEq.

K+. A major intracellular cation.

Low potassium levels in the blood. Can be caused by an insulin administration or glucose-containing fluids, vomiting of stomach contents, or diarrhea. Urinary losses can occur in chronic renal failure patients, postobstructive diuresis, dialysis, hyperadrenocorticism, or primary hyperaldosteronism. Can be caused by certain medications (loop diuretics, penicillins, etc.). Signs vary from patient to patient and also depend on severity. Signs include PU/PD, a decrease in urine-concentrating capabilities, and even muscle weakness possibly leading to respiratory paralysis. Cardiovascular signs includedekayed ventricular repolarization, increased duration of action potential, and an increased automaticity. Supraventricular and ventricular dysrhythmias may be seen. A prolongation of the QT interval may be seen with levels less than 2.0mEq/L, and patients may become unresponsive to antiarrhythmic therapy. Can treat with KCl or potassium phosphates.

IV KCl supplementation guidelines
IV KCl supplementation guidelines

Elevated levels of potassium in the blood. Uncommon in patients with normal renal function and urine output. Can be seen in diabetic patients due to insulin deficiency and hyperosmolality. Can be caused by decreased urine production from a urethral obstruction, ruptured bladder, or anuric/oliguric renal failure. Can be caused by hypoadrenocortisism. ECG will show shortening of the QT interval, tented T-waves, prolongation of the PR interval, widening of QRS complex, and disappearance of the P wave. These dysrhythmias can progress to atrial standstill and asystole. This is a life-threatening condition and needs to be treated immediately. A value greater than 6.5mEq/L needs immediate treatment. Can be treated with fluid therapy and other IV supplements.

Calcium gluconate 10% solution
Used to treat hyperkalemia. Administered at a dose of 2-10mL total to protect the heart against the effects of hyperkalemia on electrical conduction. Effects are short-lived, so further correction of potassium levels is required.

Sodium Bicarbonate
Treats hyperkalemia. Administered at a dose of 1-2mEq/kg IV to help move K+ ions into cells as H+ ions leave cells.

Can be used to treat hyperkalemia by shifting potassium into the cells in exchange for sodium. The dose is 0.55-1.1mcg/kg IV for dogs and 1 unit per cat. There is a risk of hypoglycemia, so dextrose may be added to fluids.

Hypovolemic shock
Caused by a loss of intravascular volume. Can occur through dehydration, acute blood loss (hemorrhagic shock), or third-space loss of fluids. Treat with acute volume resuscitation and interstitial fluid replacement. Use crystalloids. After boluses the HR should be normal, systolic BP between 90-120mmHg, and CRT and MM should be improved. Can use hypertonic crystalloids (alone or mixed with colloids) to help with intravascular volume expansion.

Shock bolus
90mL/kg for a dog, 55mL/kg for a cat. Can be given in aliquots (1/4, 1/3, etc.) over 10-15 minutes and then the patient reassessed to avoid fluid overload.

Cardiogenic shock
Use a diuretic to help redistribute fluid from the lungs back into circulation, give inotropic support, and give antiarrhythmic agents as needed. Fluid therapy is typically contraindicated.

Obstructive shock
Causes are pericardial effusion causing cardiac tamponade, heartworm disease leading to caval syndrome, pulmonary thromboembolism (PTE), aortic thromboembolism, and cardiac neoplasia. Can also be caused by GDV due to decreased ventricular filling due to decreased venous return. Initiating a moderate or maintenance fluid therapy is appropriate while attempting to find and treat the underlying cause, except in GDV patients. In these patients, a shock bolus is indicated to help restore vascular volume.

Whole blood
Most commonly used of all blood products. Dosed at 13-22mL/kg or can be calculated using the desired PCV, the current PCV, and the donor PCV. Combined with an anticoagulant during the collection process. Must be used within 8 hours of collection. Used in anemic patients for oxygen-carrying capacity and in patients with coagulation factor deficiency. Don’t sue solely for coagulation factors as this can lead to iatrogenic polycythemia.

Calculating whole blood transfusion volume
[(Desired PCV – Actual patient PCV) / PCV of donor blood] x Recipient blood volume

Canine blood volume

Feline blood volume

Packed red blood cells. Whole blood that has been centrifuged into packed red blood cells and plasma. One unit from a canine would contain around 200mL/unit and have a hematocrit of 80%. Used for restoring and maintaining enough of an oxygen supply to meet tissue demands. Used to treat anemia due to blood loss, hemolysis, and bone marrow dysfunction. Decision to transfuse should be based in cardiovascular status, anticipated blood loss, ability of bone marrow to respond, chronicity of the anemia, and patient’s hemoglobin and hematocrit values.

Fresh frozen plasma. Collected and frozen within 8 hours to maintain clotting factors V and VIII. Contains electrolytes, albumin, globulins, coagulation factors, and other proteins. Used to treat coagulation deficiencies dipped to rodenticide intoxication, vitamin K-dependent coagulopathies, hemophilia B, von Willebrand’s disease, and hemophilia A. The dose is 6-10mL/kg IV over 4 hours.

Collected by thawing FFP at a temperature of 1-6C until a thick white precipitate is formed and centrifuges off. Contains factors VIII:C, XIII, von Willebrand’s factor, and fibrinogen. Dose is 1 unit per 10 kg. Decreased risk of volume overload in patients compared to FFP.

Human immunoglobulin
IGg. Used along with immunosuppressive therapy to treat immune-mediated hemolytic anemia. Prepared from pooled human plasma and therefore still runs a risk of reaction with repeated doses. The dose is 0.5-1gram/kg and is administered over 6-8 hours. Expensive.

Dog erythrocytes antigen, can be negative or positive. Over 13 canine blood types, but testing is available for only 6 of them for lab use.

Cat blood types
One blood group that contains types A, B, and AB. Type A will have antibodies against type B, and type B will have antibodies against type A. All cats should be typed prior to transfusion and should be cross-matched with donors in their type to avoid a transfusion reaction.

Mik antigen
Found in cats, negative inticated anti-Mik antibodies and could cause a hemolytic transfusion reaction.

act of determining the compatibility of two blood specimens. Any patient that has received a transfusion in the past (greater than 4 days) needs this done before receiving a transfusion.

Thaw FFP. Inspect any unit for leaks or signs of contamination. No medications should be added to the transfusion line after it is being administered. Normal saline is the only fluid type compatible with a transfusion. All products should be administered through a 170 micron filter to remove clots or debris. An 18 micron filter can be used if using a syringe. Full volume must be administered within 4 hours to avoid contamination. Get a TPR, then administer products. The first 15 minutes should be given at half the rate, then recheck TPR. If still WNL, double the transfusion rate. TPR should then be checked every 30 minutes to monitor for a reaction.

Hemolytic train sfusion reaction
Clinical signs include hemoglobinuria, hemoglobinemia, icterus, and fever.

Febrile, nonhemolytic reaction
An increase in temperature by 1 degree.

Signs of transfusion reaction in dogs
Restlessness, salivation, incontinence, dyspnea, hypotension, collapse, convulsions, vomiting, and acute death (uncommon). Under anesthesia, these signs may not be apparent and trends should be monitored.

Signs of transfusion reaction in cats
Acute death (B cat given A blood). Extension of limbs and apnea. Increased respiratory and heart rate, shock, hypotension.

Treating transfusion reactions
Immediately stop transfusion, give crystalloid fluid with antipyretics. If not severe, give antihistamines and reduce the transfusion rate.

Blood Pressure — Funds Quiz

4 Vital Signs
1.) Body temperature
2.) Pulse
3.) Respiratory rates
4.) Blood pressure

Values of significance in vital signs
1.) Body temp- 98.6*F
2.) Pulse- Normal = 60-100
3.) Respiratory rates- Normal = 14-20

Normal Blood Pressure
Systolic- <120 mmHg Diastolic- <80 mmHg

Prehypertension (High normal)
Systolic= 120-139 mmHg
Diastolic= 80-89 mmHg

Stage 1
Systolic= 140-159 mmHg
Diastolic = 90-99 mmHg
Stage 2
Systolic= >160 mmHg
Diastolic= >100 mmHg

Vital signs contributes to…
The proper systemic evaluation of a patient in conjunction with the complete medical history.

Normal body temperature
-Adults- 98.6 *F
-Older adults (70 or over)- 96.8*F
1st Year: 99.1*F
4th Year: 99.4*F
5th Year: 98.6*F
12th Year: 98.0*F

Temperature variations
1.) Fever (pyrexia) values OVER 99.5*F
2.) Hyperthermia values OVER 105.8*F
3.) Hypothermia values BELOW 96.0*F

Factors that alter body temperature
1.) Time of the day (highest in late afternoon; low during sleep and early morning)
2.) Temporary increase (excercise)
3.) Pathologic states (infection)
4.) Decrease (starvation)

Locations for determining temperature
-Medical/hospital applications

Types of thermometers
1.) Electronic with digital readout
2.) Tympanic
3.) Mercury in glass: oral – blue tip; rectal – red tip
4.) Disposable single-use chemical strip

Care of patient with temp elevation
Over 105.8 *F
– Treat as a medical emergency
– Check possible temp. cause, review history, postpone oral care

-The intermittent throbbing sensation felt when the fingers are pressed against an artery
-The result of the alternate expansion and contraction of an artery as a wave of clood is forced out from the heart

Pulse rate
Count of the heartbeats

Normal pulse rates
1.) Adults (NO absolute normal)= 60-100 bpm
2.) Children
In utero – 150 bpm
At birth – 130 bpm
2nd year- 105 bpm
4th year- 90 bpm
10th year- 70 bpm

Factors that influence pulse rate
-Increased pulse: Excercise, stimulants, eating, heat/cold
-Decreased pulse: Sleep, depressants, fasting
-Emergency situations: Heart failure, cardiac arrest

Sites for determining pulse rate
-Radial pulse
-Temporal artery/facial artery
-Carotid pulse
-Brachial pulse

-Function is to supply oxygen to the tissure and to eliminate CO2
-Variations may be shown in rate, rhythm, depth, & quality
**A respiration is one breath taken in and let out!**

Normal respiratory rate
1.) Adults= 14-20 per min
2.) Children
1st year- 30/min
2nd year- 25/min
8th year- 20/min
15th year- 18/min

Factors that influence respirations
-Increased respiration: work, excercise, excitement, shock
-Decreased respiration: sleep, pulmonary insufficiency
-Emergency situations: heart problems

Factors to observe during respirations
1.) Depth
2.) Rhythm
3.) Quality
4.) Sounds
5.) Position of patient

Blood pressure
-The force exerted by the blood on the blood vessel walls
-Changing constantly

Components of blood pressure
1.) Systolic- peak/highest pressure= Ventricular contraction
2.) Diastolic- Lowest pressure= Ventricular relaxation
3.) Pulse pressure- difference b/w systolic and diastolic pressures= less than 40 mmHg
** 120/80 mmHg

Blood pressure depends on:
1.) Force of th heartbeat
2.) Peripheral resistance
3.) Volume of blood in the circulatory system

Sphygmomanometer (blood pressure machine)
*Most preferred!
-Consists of inflatable cuff, 2 tubes: 1 connected to pressure hand control bulb and other to pressure gauge
1.) Cuff
-Nonelastic material w/velcro overlap
*Diameter of arm, not age of patient, determines the
size of the cuff selected*
2.) Mercury Manometer
-Gauges are marked w/long lines at each 10 mmHg
**When cuff is too narrow, bp is too high; when cuff is too wide, bp is too low**

Stethoscope (listening aid)
-Consists of endpiece
1.) Types of endpieces: bell-shaped or flat
2.) Care of earpieces: clean by rubbing

Procedure for determining blood pressure
1.) Prepare patient
2.) Apply cuff
3.) Locate radial pulse
4.) Position stethoscope endpiece- in antecubital fossa
5.) Inflate cuff- inflate until radial pulse stops, & pump 20/30 mmHg beyond where pulse was no longer felt
—> Max. Inflation Level (MIL)
6.) Deflate cuff gradually- 2 to 3 mm per second, systole: (1st sound) “tap tap”
7.) Repeat for confirmation- wait 2-3 mins
8.) Record- in fraction

Blood pressure follow-up
-Within a normal range = rechecked w/in 2 years
-Recc. for persons at increased risk for hypertension = rechecked w/in 1 year

Common Abbreviations used in blood tests

four classifications of blood groups

antidiuretic hormone

alpha-feto protein

ALP;alk phos
alkaline phosphatase

antinuclear antibody

acetylsalicylic acid

blood urea nitrogen


complete blood count


creatine kinase

carbon monoxide



creatinine clearance


differential count

epstein barr nuclear antigen

epstein barr virus

ethylenediaminetetraacetic acid


estrogen receptor protein

erythrocyte sedimentation rate

fasting blood sugar

free fatty acids

follicle stimulating hormone

free thyroxine 4

glomerular filtration rate

growth hormone

glucose tolerance test

hepatitis A virus


hepatitis B virus

human chorionic gonadotropin


hepatitis C virus

high density lipoprotein

human growth hormone

human immunodeficiency virus

human papillomavirus

herpes simplex virus



lactate dehydrogenase

low density lipoprotein

luteinizing hormone


mean corpuscular volume

mono monocytes

median platelet volume

packed cell volume




prostate specific antigen

prothrombin time

parathyroid hormone

partial thromboplastin time

red blood count

red cell volume


rheumatoid factor

rhesus factor


segmented neutrophils

serum protein electrophoresis



total blood volume


thyroid stimulating hormone

veneral disease research laboratory

western blot

white blood cell

complete metabolic panel

basic metabolic panel

rapid plasma reagin

aspartate aminotransferase

alanine aminotransferase

total iron binding capacity

carcinoembryonic antigen

enzyme linked immunosorbent assay

calculating estimated blood loss for techniques written final

when is blood loss monitored during surgery?

why is blood loss monitored during surgery?
aids the surgeon in knowing if there is a need for a blood transfusion or auto-transfusion.

what collects and monitors blood and body fluids suctioned from the field?
canisters and suction devices.

what is the math equation for blood and fluid loss during surgery?
amount of fluid in suction bottle/canister=loss

What can the circulator weigh to help determine the amount of blood loss?
weigh the sponges.

who should be keeping track of irrigation fluids used in surgery; example, saline.
surgical tech

what should the surgical tech place in the room so that the circulator can weigh the sponges for blood loss?

used between the suction tubing and the vacuum source to collect and monitor the amount of blood and body fluids suctioned from the field.
calibrated suction devices

what is subtracted from the total volume of fluid in the canister to give a more accurate measurement of blood loss?
amount of irrigation fluid administered during procedure.

what two surgical procedures are bloody and usually call for blood replacement?
prostate and cardiovascular

which two specialist decide if blood replacement is necessary?
surgeon and anesthesiologist

blood replacement involves the administration of whole blood or blood components. what are those blood components?
plasma, packed red blood cells, or platelets via IV line.

what three things does blood replacement provide for the patient?
increase circulating blood volume
increase number of red blood cells
provide plasma clotting factors

blood products donated by another person are called what?

blood products donated previously by the patient and stored or obtained through autotransfusion is called what?

what two things are essential when homogous is used to prevent transfusion reaction?
blood typing and cross-matching

what four things do you need to know in order to weigh surgical sponges?
1.amount of saline used for weighed sponges
3.anesthesia estimate for drapes
4.amount of fluid in suction bottle

what kind of scale is used for weighing sponges
gram scale
1g=1ml of of blood

adjust scale to the left of zero to reflect the dry weight of the type of sponges you will be weighing. what does 1 4×8 sponge weigh, 10 4×8 sponges and 1 lap sponge weigh?
1 4×8=5g
10 4×8=50g
1 lap= 20g

what do you have to do as a surgical tech every time sponges are weighed and totaled?
tell the anesthesiologist

how are 4×8 sponges weighed?
in groups of 10

how are lap sponges weighed?

who determines the procedure for moistening sponges?
hospital policy

Anesthesia – fluid replacement in blood loss

How do you assess the amount of blood loss, visually?
– Surgical field
– Drapes
– Suction bottles
– Irrigation fluid
– Spondges
– Within an organ removed
– In a horse trailer, kennel, etc.

How much blood does a 4×4 gauze sponge hold?
15 ml

How much blood will a lap sponge hold?
50-75 ml

How can you directly assess blood loss?
Blood in a suction jar.

(PCV of suction jar/pre-op PCV of patient) x volume of jar = estimated ml of blood in suction jar

How can amount of blood loss be assessed through physiologic observation?
– BP decrease
– Decrease in PCV, TP, hemoglobin
– Decrease in urine output
– Increase in heart rate (ESPECIALLY IN DOGS)
– Increase in vasoconstriction
– Decreased tissue perfusion and oxygenation
– Decreased ET CO2

When is oxygen transport compromised?
PCV is less than 20%

When is there depressed cardiac function?
PCV is less than 30%

Rules of thumb: When should you do a blood transfusion?
– Acute loss of greater than or equal to 20% of blood volume
– PCV is less than or equal to 20%
– Plasma protein is less than 3.5 g/dl
– Hemoglobin is less than 7-10 g/dl

What are some other things that would suggest a blood transfusion is needed?
– Patient is unresponsive to crystalloids/colloids
– Hypovolemic shock: pale MM, prolonged CRT, increased HR and RR, decreased arterial BP, decreased CVP

What are some considerations for determining if a transfusion is needed?
– Is anemia acute or chronic?
– What is the cause?
– Is there potential for more blood loss?
– How did the patient respond to other supportive therapies?
– What is the status of the patient (cardiopulmonary, renal, etc.)?

T/F: It is harmful to transfuse a normal PCV?

As hematocrit increases, so does blood viscosity, which may not be desirable in a patient with poor tissue perfusion from acute hemorrhage/shock.

How do you calculate blood volume?
– 6-8% of total body weight in kg


– 60-80 ml/kg

What is considered minimal blood loss?
Less than 10% of blood volume

What should you do when there is minimal blood loss during surgery?
Use crystalloid volume replacement; 3ml of crystalloid for every 1 ml blood lost

– Monitor for hemodilution (PCV, TP, BP)
– Monitor clinical status (CV function, perfusion, BP, HR, etc.)

What can CV depression be exacerbated by?
– Further blood loss
– Anesthetic drugs
– Hypothermia
– Positioning
– Over ventilating

What is considered moderate blood loss?
10-20% of blood volume

What should you do during moderate blood loss?
– May increase surgical rate of bolus crystalloid
– Consider an IV bolus of colloid (several times to expand IV volume w/less risk of peripheral edema)


What is considered a severe loss?
Greater than or equal to 20% of blood volume

What should you do during severe blood loss?
Give fresh whole blood (provides RBCs plus plasma, coagulation factors, etc.); stored has less clotting factors.

What should you give if whole blood is not available?
Combination of PRBC and fresh frozen plasma.

20 ml/kg whole blood will raise hematocrit by what %?

10 ml/kg of packed red cells will raise hematocrit by what %?

What are some signs that transfusion is effective?
– HR normal
– Improved systemic BP
– Increased urine output
– Normal central venous pressure
– Pink MM
– Increased expired CO2 (indicates improved perfusion/cardiac output)

What are some risks of blood transfusion?
Acute hemolytic reaction (intravascular hemolysis) within the first few hours:
– Hypotension
– Tachyardia

Acute hypersensitivity reaction due to histamine release usually within the first 45 minutes
– Hypotension
– +/- tachycardia and urticaria
– Bronchoconstriction

What are some other risks of blood transfusion?
– Delayed hemolytic reaction (3 days to 3 weeks)
– Viral, bacterial contamination
– Cardiac overload
– Citrate toxicity (hypocalcemia)
– Hyperkalemia (old, stored blood)
– Cats (wrong type blood given — A vs. B)

How can you prevent transfusion reactions?
– Universal donors
– Cross-match (especially if previous transfusion, ALL cats)
– Store blood properly
– May pre-treat w/diphenhydramine or glucocorticoids

What is cross-matching in cats? What happens if A blood is given to a B cat?

AB antigen blood group system; A, B, or AB

A positive: MOST cats
B positive: SOME cats; 95% of B cats possess IgM anti-A

If A blood is transfused into B cats, rapid destruction results in severe clinical reactions; hypotension, apnea, AV-block within a few minutes.

Dog erythrocytes antigen
8 DEA recognized.

Universal donor: DEA 1.1; safer to use in a dog that has never been transfused

Ideally, you should know the blood type and do a cross-match.

Increased risk of hemolytic disease with subsequent transfusions.

What is the lethal triad?
– Hypothermia
– Acidosis
– Coagulopathy

Introduction of a new patch analyzing sweat to detect blood sugar levels

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Unlike finger pricking, the traditional method of monitoring levels of the blood sugar glucose, the new patch detects the levels of glucose in a person’s sweat. Research has shown that glucose level in sweat accurately reflect glucose levels in the blood.

The researchers also showed that the patch can deliver the diabetes drug metformin through the skin and that it can reduce high blood glucose levels.

The researchers are very interested in making the patch commercially available, and are talking about it with several companies in Korea, said study co-author Hyunjae Lee, of the Institute for Basic Science in Seoul, South Korea.

But more research is needed before the patch can be used in people with diabetes, the researchers said. Scientists have been looking for a noninvasive way to monitor the levels of glucose, in people with diabetes, because finger pricking can be painful and some patients are unwilling to do it, the researchers said.

To make the new patch, the researchers combined gold particles and grapheme a type of material that shows promise for use in wearable electronics because it is flexible, and can be transparent, soft and very thin, the researchers said.

A photo of the diabetes patch partially peeled off from the user’s skin. The patch consists of wearable sensors that detect the levels of glucose in sweat, as well as an integrated system with micro-needles that deliver the glucose-regulating drug metformin. When the sensors detect a high level of glucose in the sweat, heaters embedded in the patch prompt the micro-needles to release the drug and lower the glucose level.


In this project, our aim is to detect the glucose level of the individual using the thermal images of the palm. Here we use Mid infra-red rays to detect the glucose level instead of Near infra-red rays because although near infra-red light is not blocked by water making it suitable for human body, it interacts with a number of acids and chemicals in the skin which makes it unsuitable for detecting glucose level.

In the most basic of terms, thermal imaging allows you to see an object’s heat radiating off itself. Thermal cameras more or less record the temperature of various objects in frame, and then assign each temperature a shade of color, which lets you see how much heat its radiating compared to objects around it.


Colder Blue, Purple, Green

Warmer Red, Orange, Yellow

Thermal cameras detect temperature by recognizing and capturing different levels of infrared light. This light is invisible to the naked eye, but can be felt as heat if the intensity is high enough.

All objects emit some kind of infrared radiation, and it’s one of the ways that heat is transferred. If you hold your hand over some hot coals on the grill, those coals are emitting a ton of infrared radiation, and the heat is transferred to your hand. Furthermore, only about half of the sun’s energy is given off as visible light, the rest is a mix of ultraviolet and infrared light.

The hotter an object is, the more infrared radiation is produced. Thermal cameras can see this radiation and convert it to an image that we can see with our eyes. Inside the thermal camera, there are a bunch of tiny measuring devices that capture infrared radiation, called microbolometer records the temperature and then assigns that pixel to an appropriate color.

As you might have guessed, this is why most thermal cameras have an extremely low resolution compared to modern TVs and other displays. Most thermal cameras rely on longer wavelength of infrared, whereas typical night vision security camera captures shorter wavelength of infrared. Thermal compression the other hand, have the ability to capture longer wavelengths of infrared, allowing to detect heat.

Recent research as an uncovered a link between insulin and temperature. Insulin seems to work as an internal thermostat, helping to raise core body temperature by triggering the burning of “brown fats” cells. Many type1 diabetes have a low core body temperature that is below 97degree is one of the earlier signs of the disease whereas the type2diabetes warm a body rather than cooling it.

Since, body temperature depends on the level of glucose in the body it is possible for us to detect the sugar level using thermal camera which produce images depending on the temperature.

After selecting the required images for analysis, four regions of interest were identified on the acquired images. A series of tests are need to done using thermal camera. After comparing images, the approximate glucose level can be detected.


Detecting the glucose level using thermal image can bring new revolution in the sugar level detection. In the initial stage, invasive methods are used which can be banded by non-invasive methods like patch methods, ray passing methods etc. In this method, we use thermal images to detect the sugar level which makes the sugar patients free from fringe pricking method. Initially only the near infrared rays are used to detect the sugar level, in this we use middle infrared rays because it gives accurate result than using near infrared rays. The idea presented here is only the outline of the concept, showing that it is possible that the glucose can be measured using the thermal image.