laboratory techniques lat chapter 3. chapter 3 lat presentations study tips if viewing this in...
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Laboratory TechniquesLaboratory Techniques
LAT Chapter 3LAT Chapter 3
Chapter 3LAT Presentations Study TipsLAT Presentations Study Tips
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Chapter 3
Injection TechniquesInjection Techniques
• Injections with needles and syringes used to administer various substances
• Syringe construction and sizes
• Considerations for blood withdrawal
• Proper disposable of needles
and syringes
• Common routes of injection
Chapter 3
• IM generally given in hind legs. Most desirable site is large muscle mass (e.g.,
quadricep muscle group).
Alternative site: muscles posterior to femur
• Do not inject too much material.
Intramuscular Injection (IM)Intramuscular Injection (IM)
Chapter 3
• Given in lower right quadrant of abdomen. Avoid bladder and cecum.
• Slight resistance may be encountered.
• Aspirate prior to injection. Yellow fluid: needle could be in bladder
Greenish fluid: needle could be in intestine or cecum
Blood: may have entered blood vessel
Intraperitoneal Injection (IP)Intraperitoneal Injection (IP)
Chapter 3
• Given into the thick dermal skin layer.
• 25 gauge needle typically used.
• Needle directed at 20 to 30 degree angle into skin.
• Only small quantity of fluid can be injected.
0.1 to 0.2 ml
Intradermal Injection (ID)Intradermal Injection (ID)
Chapter 3
• Placed in the more vascular space between skin and underlying muscle
• Large area of subcutaneous tissue exposed by raising a tent of skin
• Entering the injection site => + then 0 resistance
• Precautions - puncture hand, inj. out other side
Subcutaneous InjectionSubcutaneous Injection
Chapter 3
• IV access sites in common laboratory animals
• Site preparation - disinfect
• Use pressure to distend the vessel.
• Insert needle at 30 degree angle to skin.
• Removing the needle - apply pressure
Intravenous Injection (IV)Intravenous Injection (IV)
Chapter 3
• Used as aid to diagnose disease Collection site and amount determined by species
and test type.
• Intravenous Technique Technique basically same as intravenous injection
Blood Collection TechniquesBlood Collection Techniques
Chapter 3
• Auricular artery frequently used for blood collection in rabbit. Artery easily visible.
Large quantities of blood can be obtained.
• Same technique as intravenous
• Apply pressure to artery after needle withdrawal.
Blood Collection - IntraarterialBlood Collection - Intraarterial
Chapter 3
• Used for animals that do not have large veins.
• Limited to rodents with large venous sinus or plexus posterior to the eye.
• Animals typically under anesthesia.
• Allow punctured vessel to clot and then place ophthalmic ointment into the eye.
Blood Collection - Retro-OrbitalBlood Collection - Retro-Orbital
Chapter 3
• To collect small samples from rodents• Blood collected from saphenous vein into a
capillary tube• Anesthesia not required• Multiple samples collected in same day
Blood Collection - SaphenousBlood Collection - Saphenous
Chapter 3
• Withdraw blood slowly• Dangerous procedure
Must use general anesthesia Will be fatal in some animals Animal typically euthanized after procedure
Blood Collection - Blood Collection - CardiacCardiac Puncture Puncture•Needle placed through chest wall and into heart
Chapter 3
• Method used to collect of several drops of blood from mice or rats.
• Method is controversial.• Justification for use may be required.• Anesthesia recommended for animals older
than weaning age.
Blood Collection - Tail TransectionBlood Collection - Tail Transection
Chapter 3
• Total Blood Volume = 6% of Body Weight Varies depending on
species, age, sex, etc.
• Guideline used when sampling frequently Volume equal to no more
than 1% of an animal’s body weight can be taken every two weeks
Example: 3kg rabbit = 30ml of blood
Blood VolumeBlood Volume
Chapter 3
• Most often used for rodents Gavage tube attached to
hypodermic syringe• Hold animal in proper position• Insert tube at approximately
45 degree angle Do not force tube
• Withdraw and start again if resistance is met while inserting the tube
Gastric Gastric Intubation Intubation (Gavage)(Gavage)
Chapter 3
• Commonly used in larger animals.• Use gag to prevent chewing of tube.• Slight resistance may be encountered when
inserting tube. Avoid entry into the trachea; delivery into lungs will
likely cause death.
• Guinea pig and chinchilla - palatal ostium
Gastric Intubation (Gavage) (cont.)Gastric Intubation (Gavage) (cont.)
Chapter 3Additional ReadingAdditional Reading
1. Crow, S.E. and Walshaw, S.O. Management of Clinical Procedures in the Dog and Cat. 2nd. Edition. Lippincott-Raven. New York, NY, 1997.
2. McCurnin, D.M. Clinical Textbook for Veterinary Technicians. 3rd Edition. W.B. Saunders. Philadelphia, PA, 1994.