Diagnostic Sampling (Large Animals) Flashcards
_____ determines which lab parameters can be evaluated.
Type of collection tube
If a serum is required > centrifugation ______________.
centrifugation after clotting of a whole blood sample
If plasma is required > centrifugation _______________.
centrifugation of unclotted blood yielding serum + fibrinogen
If whole blood is required > _________.
leave the sample as is
Why is it important to fill the tube to capacity if it has an anticoagulant?
Ensures the correct blood-to-anticoagulant ratio
Venous blood sample collection sites are based on what 4 things?
- Vessel condition
- Animal position
- Animal disposition
- Amount of sample needed
If repeated samples are needed > start with _____ VP site > progress _____.
Start with distal VP site > progress more proximally
Give 2 types of venous blood sample collection materials
- Syringe + needle
- Vacutainer dual-ended needle + collection tube
PROCEDURE - Venous Blood Sample Collection (General Process)
- Properly restrain patient
- Clean insertion site with isopropyl alcohol
- Occlude vessel > vessel ballottement with alcohol-soaked sponge or cotton ball
- Insert needle into vessel
- May insert with or without syringe attached - Aspirate sample with syringe or Vacutainer tube
- Remove needle > apply pressure to avoid hematoma
Which 4 veins are used for equine venous blood sampling?
- Jugular vein
- Transverse Facial vein
- Cephalic vein
- Saphenous vein
When sampling venous blood from equine jugular veins, insert:
1.
2.
- Parallel to vein
- Toward head
What are 3 steps to locate the transverse facial vein in equines?
- Place thumb at medial canthus
- Place index finger at lateral canthus
- Draw imaginary V shape diagonally down to facial crest
Where is the transverse facial vein located in equines?
- Runs transversely beneath the facial crest + above transverse facial artery
- Midway between medial canthus of the eye + rostral end of facial crest
When sampling venous blood from equine transverse facial vein, insert:
1.
2.
3.
- Perpendicular to skin beneath facial crest
- Advanced until bone felt
- Then attach syringe to aspirate
When sampling venous blood from equine cephalic vein, insert:
1.
2.
- Insert needle first > wait for horse to put foot back down > then attach syringe
- Apply pressure at removal due to increased risk of hematoma
Using the saphenous vein is unsafe to use for venous blood sampling in _______ adult equines
non-anesthetized
Which 3 veins are used for bovine venous blood sampling?
- Jugular vein
- Coccygeal vein
- Milk vein (SC Abdominal VP)
When sampling venous blood from bovine jugular veins, insert:
1.
2.
- 45º angle
- Directed cranially
Give 2 indications for coccygeal vein blood sampling in bovines
- Blood samples needed from large # of cattle
- If jugular vein is thrombosed or inaccessible
Where is the coccygeal vein located in bovines?
Ventral side of the tail
bony canals on the ventral aspect of the vertebral bodies that protect the artery and vein
Hemal Processes
When sampling venous blood from bovine jugular veins, insert:
1.
2.
- Palpate between hemal processes
- 90º angle in soft space between 2 coccygeal vertebrae > stop when bone is felt > slightly back needle out + apply suction to syringe
Where are the subcutaneous abdominal veins (milk veins) located in bovines?
Ventrolateral body wall of thorax + abdomen
Give 3 possible complications of bovine milk vein venipuncture
- Prone to prolonged + pronounced bleeding > large hematoma formation
- Infection
- Thrombosis of milk vein > insufficient udder circulation
When sampling venous blood from bovine milk veins, insert:
1.
Either direction
Which 5 veins can be used for venous blood sampling in adult camelids?
- Jugular Vein
- Saphenous Vein
- Auricular Vein
- Middle Coccygeal Vein
- Cephalic Vein
How do you locate the HIGH site for jugular blood sampling in camelids?
1.
2.
3.
- Create imaginary line along ventral border of mandible
- Drop imaginary line vertically down from just in front of the ear
- Intersection of these lines > guide for locating the vein
How do you locate the LOW site for jugular blood sampling in camelids?
1.
2.
- Palpate ventral projection of transverse process of C6
– Close to thorax + prominent - Occlude vein just above transverse process
When is the saphenous vein used for blood sampling in camelids?
Recumbent (kushed) animals
Where is the saphenous vein located in camelids?
Superficial medial aspect of stifle
Close proximity + cranial to saphenous artery
When is the auricular vein used for blood sampling in camelids?
When small amounts of blood are needed
Which 4 vessels are used for venous blood sampling in crias?
- Jugular vein
- Saphenous veins
- Cephalic vein
- Auricular vein (sometimes)
Which 4 vessels are used for venous blood sampling in ovines and caprines?
- Jugular vein
- Cephalic vein
- Femoral vein
- Auricular vein
Which 6 vessels are used for venous blood sampling in porcines?
- Cranial Vena Cava
- Jugular Vein
- Auricular Vein
- Peripheral Leg Veins
- Coccygeal Vein
- Orbital Sinus (Medial Canthus of the Eye)
Which vessels are NOT used for venous blood sampling in potbellied or pet pigs? Why not?
- Cranial Vena Cava
- Jugular Vein
Risk of death from procedure
When is the cranial vena cava used for porcine venous blood sampling?
Large blood volume needed from commercial pigs
- Transfusions
- Health certificates
Where is the cranial vena cava located in porcines?
- In thoracic inlet
- Between 1st pair of ribs
Why should you use the right side when sampling venous blood from the cranial vena cava in pigs?
Prevents damage to phrenic nerve
Hitting phrenic nerve > alter diaphragm function > cardiac/respiratory problems
How do you locate the jugular vein in porcine venous blood sampling?
1.
2.
3.
- In jugular furrow > not as deep as vena cava
- Visualize imaginary horizontal line through shoulders + manubrium sterni
- Visualize a 2nd line extending from manubrium sterni to scapula > 45º to first line
Where is the auricular vein located pigs?
- Near lateral border of pinna
- Easily visualized on dorsal side of ear
What can be done to prevent auricular vein collapse when sampling venous blood in pigs?
Without syringe attached > insert needle > allow blood to drip from needle hub > into uncapped collection tube
When sampling venous blood from peripheral leg veins in pigs, insert
1.
2.
- 45º angle to skin
- Proximal direction
What can be done to prevent peripheral vein collapse when sampling venous blood in pigs?
Without syringe attached > insert needle > allow blood to drip from needle hub > into uncapped collection tube
When is the coccygeal vein used for blood sampling in pigs?
Blood sample collection in potbellied pigs + adult pigs with intact tails
- NOT common for commercial pigs
When sampling venous blood from porcine coccygeal veins > insert:
1.
2.
- Ventral midline of tail
- Perpendicular to skin
When sampling venous blood from porcine coccygeal veins > insert:
1.
2.
3.
- Into medial canthus > deep into nictitating membrane (3rd eyelid)
- Advanced at 45º angle toward opposite jaw > stop when bone felt
- Rotate between fingers until blood enters hub > then attach syringe > collect with gentle aspiration
Arterial blood samples are used for ______.
blood gas analysis
ABG Evaluations:
Oxygen/Carbon dioxide content evaluates ____
respiratory status
ABG Evaluations:
pH levels evaluate ____
repiratory status
ABG Evaluations:
Base deficits evaluate ____
metabolic (acid-base) status
ABG Evaluations:
Bicarbonate levels evaluate ____
metabolic (acid-base) status
What materials can be used for arterial blood sampling?
1.
2.
- 2 needles (smallest gauge possible) + 1 syringe + heparin
- Commercially pre-heparinized blood gas syringe
Why is it important to change the needle out after the syringe has been coated with heparin?
Ensures the needle for sample collection is not dulled by puncturing rubber stopper of heparin vial > keep it sharp as possible > minimal damage to vessel
General Procedure - Arterial Blood Sample Collection
- Properly restrain patient > anesthesia or not based on species
- Aspirate enough heparin to coat syringe > remove needle > place new needle on syringe > expel heparin OR use commercially pre-heparinized blood gas syringe
- Palpate artery to locate > shave + surgically prepare site
- Do NOT occlude artery > insert needle with or without syringe attached > bright red blood quickly fills syringe > Collect minimum 1 mL blood if you prepped syringe OR smaller volume if pre-heparinized syringe
- Insertion with/without syringe based on patient behavior - Withdraw needle > immediately apply firm digital pressure to puncture site > hold for several minutes
- Expel any bubbles in syringe > insert needle tip into a rubber stopper > roll sample between palms > place in ice water bath if not immediately analyzed
Do NOT place arterial blood samples in _____ or _____
freezer or on ice with no water
(Veins/Arteries) are more susceptible to hematoma and thus require longer pressure at the insertion site after needle is withdrawn.
Arteries
Which 4 arteries can be used for ADULT equine arterial blood sampling?
- Facial artery
- Transverse facial artery
- Carotid artery
- Dorsal Metatarsal artery
Which 2 arteries are used for NEONATE equine (foals) arterial blood sampling?
- Brachial artery
- Palmar artery
Where is the facial artery located?
Under the mandible to the facial crest
Which artery is commonly used for arterial catheterization in anesthetized equine patients?
Facial Artery
Where is the transverse facial artery located?
Caudal to the lateral canthus of the eye
Where is the carotid artery located?
- Lower third of neck
- Dorsal aspect of jugular groove
- Deeper than jugular vein
Insert needle at _____ angle for arterial blood sampling in the equine carotid artery
90 degree angle
Where is the dorsal metatarsal artery located?
Lateral aspect of cannon bone of hind limb
Where is the brachial artery located?
Medial aspect of of proximal forearm
Where is the palmar artery located?
Abaxial surface of fetlock
Which artery is used for arterial blood sampling in camelids?
- Auricular artery
Which 4 arteries are used in bovine, ovine, and caprine arterial blood sampling?
- Transverse Facial artery
- Carotid artery
- Auricular artery
- Dorsal Metatarsal artery
Bovine, ovine, and caprine arterial blood sampling is usually restricted to _____ or ______ patients.
anesthetized or neonatal patients
which 2 arteries are used in equine arterial catheterization?
- Transverse Facial artery
- Dorsal Metatarsal artery
Which 3 arteries are used in food animal catheterization?
- Transverse Facial artery
- Dorsal Metatarsal artery
- Auricular artery
What type of catheter is normally used for arterial catheterization of large animals?
Short OTN catheter
Arterial catheterization is usually restricted to _______ patients.
Anesthetized
Urine samples are used to screen for:
1.
2.
3.
- UTIs
- Systemic diseases
- Performance enhancing drugs (PEDs)
Which 2 systemic diseases are commonly screened for via urinalysis?
- Rhabdomyolysis
- Azoturia
a condition that causes stiffness and pain in the muscles of hindquarters and back, and is characterized by an abnormal excess of nitrogen compounds in urine
Azoturia
a condition in which muscle cells break down during intense physical activity and release myoglobin into the blood
Rhabdomyolysis
Give 3 methods of urine sample collection
- Midstream Free Catch
- Catheterization
- Cystocentesis
Which method of urine sample collection cannot be used for cultures?
Free Catch
Why is it critical to analyze urine samples promptly?
Samples degrade rapidly
List 4 possible complications of urinary catheterization
- UTI
- Mucosal irritation
- Slow + painful urination
- Bacterial contamination in sample
List some ways to encourage urination in equines
- Place horse in freshly bedded stall
- Make horse stand on grassy area
- Run water on cement + tickle prepuce with piece of straw
Equine Urinary Catheters:
Stallions
1.
2.
- 24-28 Fr Foley cath
- Stallion cath
Equine Urinary Catheters:
Colts
1.
- 12 Fr red rubber feeding tube
Equine Urinary Catheters:
Mares
1.
2.
- 30 Fr Foley cath
- Chambers cath
Equine Urinary Catheters:
Fillies
1.
- 12 Fr Foley cath
PROCEDURE - Urinary Catheterization in Male Equines
- Properly restrain patient > sedation + VT stand cranially
- Retract prepuce > grasp penis gently + firmly caudal to glans penis > wash penis with dilute antibacterial soap > clean urethral process + urethral diverticulum > rinse diverticulum if any smegma present
- Wearing sterile gloves > apply lubricant to tip of urinary catheter
- Hold penis with 1 hand + gently advance cath into urethra with other > slight force to advance cath past ischial arch (ventral to anus) > continue until in bladder
- Collect urine sample > if urine does not flow from cath >
- Attach syringe > gently aspirate
- Inject small amount of air into cath
OR
- Reposition cath - Gently remove catheter
How will you know when the urinary catheter passes over the ischial arch just before the bladder?
Horse will raise its tail
Excessive negative pressure when aspirating a urine sample from a catheter can cause ________ + _______.
minor hemorrhage + altered sample
Why should you wrap the tail + tie it out of the way before urinary catheterization of female horses?
Prevents hair from entering vagina or touching glove/catheter > introducing contaminants
PROCEDURE - Urinary Catheterization in Female Equines
- Properly restrain patient > wrap tail + tie out of the way
- Clean vulva + perineum with dilute antibacterial soap
- Put on + lubricate sterile gloves > insert hand into the vagina > slide along vaginal floor > locate urethral orifice (10-12 cm from ventral commissure of vulvar lips)
- Apply lubricant to tip of urinary catheter > slide cath in + down into urethral orifice using a finger > advance cath 5-10 cm until bladder entered
- Urine will flow once catheter in bladder > collect urine sample
- If urine does not flow from cath > – Attach syringe > gently aspirate
– Inject small amount of air into cath
OR
– Reposition cath - Gently remove catheter
How can you encourage camelids to urinate?
Lead animal to communal dung pile
Female and male ______ urinate caudally while squatting
camelids
Urinary catheterization cannot be done on male camelids, bovines, and porcines due to ______ and ______.
Sigmoid shaped penis and
membranous flap at ischial arch
PROCEDURE - Urinary Catheterization in Camelids (Females ONLY)
- Properly restrain patient
- Clean vulva lips > dry area
- Wearing sterile gloves > apply small amount of lubricant to glove > insert finger into vulva > feel for groove on floor of vulva (aka external urethral orifice)
- Once external urethral orifice located > withdraw finger slightly > slide cath along dorsal aspect of index finger into the orifice > slowly advance until cath in the bladder
- Urine will flow once catheter in bladder > collect urine sample
- If urine does not flow from catheter > attach syringe > gently aspirate - Gently remove catheter
Sliding the urinary catheter along the top of the index finger avoids accidental insertion into ________
ventral urethral diverticulum
For most adult female camelids, the catheter will be inserted ______ from the vulvar lips to enter the bladder.
25 cm
Describe some ways to encourage urination in bovines
- Place animal in chute or stanchion + allow animal to relax
- Lightly stroke vulvar tip + skin beneath vulva (cows)
- Massage prepuce + splash with warm water (steer/bulls)
PROCEDURE - Urinary Catheterization in Bovines (Females ONLY)
- Properly restrain patient
- Clean perineal area with dilute antibacterial soap > rinse with water
- Put on + lubricate sterile gloves > insert hand into vagina > slide 10 cm along vaginal floor > insert finger into suburethral diverticulum
- Apply lubricant to tip of catheter > insert cath > guide cath over diverticulum + into external urethral orifice > until in bladder
- Urine will flow once catheter in bladder > collect urine sample
- If urine does not flow from cath > attach syringe > gently aspirate - Gently remove catheter
What is the easiest way to collect urine from ewes and does?
Free catch immediately after rising from a period of recumbency
What is the less preferred way to encourage urination in ewes?
Occlude nostrils for max 45 sec while animal is standing > animal will struggle > release nostrils > animal will urinate
What tool is helpful in female ovine/caprine urinary catheterization? Why?
Small animal vaginal speculum > small vulvas
PROCEDURE - Urinary Catheterization in Female Ovine and Caprines
- Properly restrain patient > hold or tie tail out of the way
- Cleanse vulva
- Put on + lubricate sterile gloves > insert fingers 5-10 cm in to vagina > locate urethral opening (on midline of ventral vaginal surface)
– Or use a small animal speculum - Lubricate tip of 5-12 Fr urinary cath > insert catheter until in bladder
– If resistance felt > cath was accidentally fed into suburethral diverticulum (blind sac) > pull out slightly > redirect more dorsally - Urine will flow spontaneously when catheter in bladder > collect sample – Can gently aspirate if necessary
- Gently remove catheter
Direct catheterization into the bladder from the body wall via ultrasound can be done in ______.
Rams
What type of urinary catheter is used on female pigs?
Canine catheter
Fecal sample collection is used for:
1.
2.
3.
4.
5.
- Gross visual inspection
- Microscopic examination
- Microbiological culture
- Polymerase chain reaction (PCR) assay
- Osmolality + Electrolyte concentration
Fecal Sample Collection:
For each species, VT must be familiar with:
1
a.
b.
c.
d.
2.
- Normal character
- Content
- Consistency
- Color
- Odor - Volume of feces
Fresh feces provides more accurate diagnostic information for _______ and _______.
Parasite identification and cultures
PROCEDURE: Collecting Fecal Sample Directly from Equine Rectum
- Place horse in stocks
- Remove jewelry/watches + clip fingernails short
- Wear obstetric sleeve > apply generous amounts of lubrication gel
- Stand slightly to side of horse
- Touch fingertips together + form a cone > insert coned hand slowly into rectum
- Collect handful of feces > turn sleeve inside out + tie in knot > store sample
Milk samples test for _____.
Colostrum samples test for _____.
Milk samples test for MASTITIS.
Colostrum samples test for QUALITY of present colostrum.
inflammation of the mammary gland that can be caused by bacterial infection or traumatic injury to the teat or udder
Mastitis
inflammation of the mammary gland that presents obvious symptoms like a hard and hot udder, abnormal appearance or smell of the milk, and pain
Clinical Mastitis
inflammation of the mammary gland that can only be confirmed through diagnostic testing of the milk
Subclinical Mastitis
What are the 2 types of mastitis?
- Clinical Mastitis
- Subclinical Mastitis
PROCEDURE - Collecting a Sterile Milk Sample
- Properly restrain patient
- Wash + dry hands thoroughly > clean teat end of udder with alcohol-soaked cotton swab
- Repeat alcohol swabbing > until cotton is clean after rubbing the end of the teat + it dries
- Using clean + dry hands > remove top of a culture tube > hold tube so no debris will fall into tube + nothing touches opening
- Discard 1st few squirts of milk > squirt stream directly into collection tube > replace top
- Refrigerate sample for up to 24 hrs before lab processing
When collecting sterile milk samples, each _____ of the udder is considered individually in cows VS each _____ of the udder in small ruminants.
1/4 udder in cows
1/2 udder in small ruminants
a test commonly used to identify the presence of mastitis in cows, does, and ewes by using a white plastic test paddle with four cups labeled A to D and a reagent fluid
California Mastitis Test (CMT)
PROCEDURE - Collecting Nonsterile Milk Samples for CMT
- Properly restrain patient
- Clean + dry teats only
- Hold paddle in caudal direction > strip small amount of milk from each teat into each well of the paddle > discard first stream of milk > collect sample
- VT note which teat was milked into each well
- Discard first stream to avoid false positive - Add equal volume of CMT reagent solution to each well > gently swirl milk in paddle
- Grade resultant solution based on gel formation > number = severity of infection
Why do you only wash the teats for the CMT?
If whole udder washed > increased risk of introducing contaminants into teat orifice
CMT Gel Formation:
No gel
0
CMT Gel Formation:
Precipitate disappears with continued movement of sample
Trace
CMT Gel Formation:
1st visible precipitate does not disappear
1
CMT Gel Formation:
1st visible gel - mixture moves toward center of the cup + leaves the bottom of the outer edge of the cup exposed
2
CMT Gel Formation:
Egg yolk-type clot sticks to the bottom of the plate + may have appearance of cottage cheese
3
a hydrometer that measures specific gravity of a sample and converts it to IgG concentration to determine the quality of the sample
Colostrometer
How much volume is needed to use a colostrometer?
5-10 mL
Lab analysis of colostrum includes:
1.
2.
- Immunoglobulin G (IgG) content
- Antierythrocyte alloantibody determination
PROCEDURE - Collecting a Colostrum Sample
- Properly restrain patient > before milking + after foaling
- Wash udder well with soap saturated cotton swab + warm water > rinse well
- Collect 5-10 mL of colostrum
- Milk directly into collection tube
OR
- Pour from another container into necessary tubes - Use colostrometer to analyze
Give 2 uses for collected rumen fluid
- Diagnosis of forestomach diseases in ruminants
- Transfaunation
To diagnose forestomach diseases in ruminants, rumen fluid is evaluated for:
1.
2.
3.
4.
5.
- Color
- pH
- Odor
- Microbial organisms + numbers
- Electrolyte levels
inoculation of a sick animal’s rumen with normal rumen flora needed to aid digestion
Transfaunation
Rumen fluid can be collected via _______ or _______.
OGT intubation or Rumenocentesis
Why is it important to NOT overly elevate the head in bovine OGT intubation?
Decreases likelihood of aspiration of fluid
- Properly restrain patient
- Measure + mark OGT from mouth to rumen
- Place speculum > feel for “pop” as speculum passes into pharynx
- Lubricate tip of tube > insert through speculum > advance down esophagus > confirm placement in esophagus
- Advance OGT into rumen > confirm placement
- Collect sample with dose syringe > discard initial fluid to avoid erroneous elevated pH amounts
- Kink tube > withdraw tube in smooth + downward motion
- Immediately measure pH + test fluid > rumen fluid degrades immediately upon removal
How can you confirm placement of an OGT in the esophagus? Give 2 methods
1.
2.
- Visualize in esophagus
- Palpate for 2 distinct tubular structures > trachea + OGT
How can you confirm placement of an OGT in the rumen? Give 4 methods
- Blow into tube + listen for gurgling from end of tube
- Blow into tube + assistant auscultate abdomen to listen for gurgling
- Smell exposed end of tube
- Aspiration of rumen fluid
Why do you have to immediately measure the pH and test the fluid after rumen samples are collected?
Rumen fluid degrades immediately upon removal
What is the role of the VT in rumenocentesis?
Prepare patient + procedure
- Needle + syringe
- 14 gauge > cattle
- 16-18 gauge > small ruminants - Clip + surgically prepare insertion site
- Ventral abdomen caudal to xiphoid process
- Left of ventral midline
Pleural fluid ______ + _______ changes with disease in the pleural cavity or lungs
volume + character
Gross analysis of pleural fluid includes:
1.
2.
3.
4.
5.
- Color
- Opacity
- Presence of fibrin
- Pus
- Odor
Lab analysis of pleural fluid includes:
1.
2.
3.
4.
5.
- Cytologic examination
- Microbiological examination
- pH
- Lactate
- Glucose
Why might a thoracocentesis be indicated for both lungs?
Diseases in pleural cavity can cause blockages of normal communication between left + right sides > each side may have different lab results
Give 3 possible complications of a thoracocentesis
- Pneumothorax
- Dyspnea
- Iatrogenic infection
What is the role of the VT during a thoracocentesis?
- Set up for procedure
- Prepare patient
- Assist with procedure
- Postprocedural care
Preferred thoracocentesis site in equines and bovines is
______ on the left side
______ on the right side
7th-8th intercostal space > left side
6th-7th intercostal space > right side
PROCEDURE - Thoracocentesis in Equines + Bovines
- Only performed by the vet
- Properly restrain patient > sedate
- Vet chooses appropriate site on right or left lateral thorax > VT shave + aseptically prepare large area
- SC inject 5mL lidocaine bleb on cranial aspect of rib + deep enough into intercostal muscles to include parietal pleura > vet makes stab incision
- Needle/catheter/cannula with attached extension tubing + stopcock inserted near cranial rib border > advance through parietal pleura
- Once in pleural cavity > attach syringe to stopcock > aspirate fluid
- Vet may stitch purse-string suture around stab incision + tighten suture as cannula removed
Preferred thoracocentesis site in camelids is
_________ + __________
6th or 7th intercostal space + 10-15 cm dorsal to sternum
PROCEDURE - Thoracocentesis in Camelids
- Only performed by the vet
- Properly restrain patient >
- Vet chooses appropriate site on right or left lateral thorax > VT shave + aseptically prepare injection site
- Tape back any long fibers that may contaminate site - SC inject 5mL lidocaine bleb on cranial aspect of rib + deep enough into intercostal muscles to include parietal pleura
- Insert needle/cannula with attached syringe near cranial rib border > advance 2-3 cm under skin
- Once in pleural cavity > aspirate fluid
- Remove needle > apply antibiotic ointment to site
Transtracheal washes can assist in the diagnosis of:
1.
2.
- Lower airway disease
- Lung disease
the collection of fluid from the bronchi, bronchioles, and alveoli (lower respiratory tract) for cytologic and microbiological analyses
Transtracheal Aspiration
List 2 tracheal wash methods
- Percutaneous Method
- Endoscopic Method
Why is heavy sedation avoided during transtracheal washes?
It suppresses the cough reflex
Do NOT exceed _____ of total volume of saline infused during a transtracheal wash
50 mL
Give 8 possible complications of transtracheal aspiration
- Cellulitis at puncture site > apply warm compress
- SC abscessation at puncture site > apply warm compress
- SC emphysema around trachea
- Pulmonary foreign body due to piece of cath in airway
- Acute dyspnea
- Tracheal laceration
- Minor SC hemorrhage
- Iatrogenic infection
PROCEDURE - Percutaneous Transtracheal Aspiration (Large Animal)
- Properly restrain patient
- Select site > midline of neck + 1/3 down the neck + directly over trachea > shave + aseptically prepare 4x4 inch area over selected site
- Inject 1-2 mL of 2% lidocaine ID + SC over selected site > apply a final preparation
- Open trach wash kit > put on sterile gloves > remove the long catheter > tie the long catheter in a loose half-hitch knot
- Make stab incision with scalpel blade through skin + between tracheal rings > grasp cannula from the kit with 1 hand + stabilize trach with other hand (palm side up) > place fingers + thumb on each side of trach > hold firmly
- Insert needle bevel side DOWN through incision > advance into tracheal lumen > burst of air exits needle once inside lumen
- If resistance > redirect needle tip between tracheal ring spaces > advance again - Remove stylet > place on a sterile field in case needed again
- Insert cath until it reaches the thoracic inlet
- Attach the 60mL syringe > retract plunger > air aspirated into catheter
- If no air aspirated > reposition catheter - Infuse 30mL of NaCl > immediately try to aspirate 5mL or larger fluid sample
- Continue aspirating slowly + withdraw catheter > stop withdrawing when fluid for aspiration is evident > collect as much as possible with a catheter at that location
- Withdraw again (as needed) to continue fluid collection
- Do NOT reinsert catheter
- If fluid is not obtained > infuse 10mL of NaCl > aspirate again - Remove cannula > apply pressure to site > place antiseptic ointment + gauze over incision for 24 hours
- Cap the sample syringe with a sterile needle for transport to the lab
Endoscopic transtracheal aspiration allows for visual examination of:
1.
2.
3.
4.
- Upper airways
- Trachea
- Carina
- Primary + secondary bronchi
PROCEDURE - Endoscopic Transtracheal Aspiration (Large Animal)
- Properly restrain patient
- Insert endoscope through nasal cavity > advance into tracheal lumen
- Insert polyethylene tubing OR an endoscopic microbiological aspiration cath through endoscope
- Inject fluid > immediately aspirate fluid for sample collection
- Remove specialty tubing > gently remove endoscope > cap sample syringe with sterile needle for transport to lab
a procedure used to collect fluid samples from the lower airway and represent a limited area of the lung
Bronchoalveolar Lavage (BAL)
PROCEDURE - Bronchoalveolar Lavage (BAL) in Large Animals
- Properly restrain patient
- Pass BAL tubing into trachea > inject 2% lidocaine whenever animal coughs
- Acts as local anesthetic to bronchi > decreases cough reflex
- Common to use entire 50mL before procedure is complete - Advance BAL tubing until gentle resistance is felt
- Infuse 30mL of normal saline > immediately try to aspirate 5mL or larger fluid sample
- Gently remove tubing > cap sample syringe with sterile needle for transport to lab
If vet intends to perform both percutaneous transtracheal aspiration + BAL > why is the trach wash performed FIRST?
Give 2 reasons
- Allows collection of fluid samples before any contamination introduced by passing the BAL tubing
- Cough reflex
- Intentionally suppressed > BAL
- Desirable > trach wash
The _______ is directly related to the composition of peritoneal fluid
condition of abdominal organs
Analysis of peritoneal fluid includes:
1.
2.
3.
- Gross appearance
- Lab results
- Volume present (ascites are abnormal)
Give some indications for an abdominocentesis
- Colic
- Suspected peritonitis
- Weight loss
- Abdominal distention
- Chronic diarrhea
- Signs of internal hemorrhage
- Abnormal ultrasound findings
- FUO
What are the responsibilities of the VT during an abdominocentesis?
- Prepare for procedure
- Assist OR perform procedure
- Vet will tell you which method they prefer - Ensure sample is not contaminated
- Ensure contaminants not introduced to patient
- Ensure as little trauma as possible inflicted upon patient
- Ensure personnel are not injured while collecting sample
How is the insertion site determined in an equine abdominocentesis?
1.
2.
- Locate lowest portion of the abdomen + ventral midline
(2-4” caudal to xiphoid) - 1-2” to the right of midline
(Reduces chance of tapping spleen)
For an abdominocentesis, do NOT tap through:
1.
2.
3.
- Skin abrasions
- Surgical lesions
- Edema
List 3 methods for abdominocenteses in adult equines
- Teat Cannula or Bitch Catheter Method
- 18-22 Gauge x 1.5” Needle Method
- 18 Gauge x 3.5” Needle Method
Why is the teat cannula/bitch catheter abdominocentesis method used for adult horses with abdominal or bowel distention?
Method reduces risk of bowel penetration
PROCEDURE - Abdominocentesis in Adult Equines (Teat Cannula/Bitch Catheter Method)
- Create a sterile field: Open a pair of sterile gloves > place teat cannula/bitch cath/needle + scalpel blade + sterile gauze onto the gloves
- Put on sterile gloves
- Puncture center of 1 gauze sponge with scalpel > put teat cannula through the gauze
- Make stab incision through skin with scalpel: Hold blade with 3/8” exposed > gently touch horse’s belly with back of gloved hand > insert scalpel straight into the bleb > pull it straight out
- Avoid cutting the musculature - Slowly + firmly insert teat cannula through incision + perpendicular to musculature > slight pop when peritoneum punctured > decreased resistance when abdomen entered – If firm resistance felt > may have hit an organ
- Once cannula in abdomen > wait while horse takes a few breathes > fluid flows from cannula – If fluid does not immediately flow
- Gently flick cannula with finger
- Move around / slightly / rotate / redirect OR
- Aspirate - Discard first few drops of fluid > collect at least 1mL of sample via gravity flow into EDTA tube first > collect a drop or 2 of sample in serum tube
- Guard close to insertion site with fingers > prevent any omentum attached to cannula from coming out > apply manual pressure to site to stop any bleeding
- Clean site gently + apply antibiotic ointment daily for a few days
Refractometry:
Excessive EDTA in relation to sample size can result in ______.
false protein elevation reading
In which adult horses is the 18 gauge x 3.5” spinal needle abdominocentesis method indicated?
- Very large horses
- Draft horses
- Obese individuals
Which adult equine abdominocentesis method requires a local anesthetic?
Teat Cannula / Bitch Catheter Method
PROCEDURE - Abdominocentesis in Adult Equines (18 Gauge x 3.5” Spinal Needle Method)
- Create a sterile field: Open a pair of sterile gloves > place needle + sterile gauze onto the gloves
- Put on sterile gloves
- With stylet in place > insert needle 1/4” into skin > remove stylet > advance needle further > slight pop when peritoneum punctured > decreased resistance when abdomen entered – If firm resistance felt > may have hit an organ
- Once needle in abdomen > wait while horse takes a few breathes > fluid should flow into hub
- Remove needle clean site gently + apply antibiotic ointment daily for a few day
PROCEDURE - Abdominocentesis in Adult Equines (18-22 Gauge x 1.5” Needle Method)
- Create a sterile field: Open a pair of sterile gloves > place needle + sterile gauze onto the gloves
- Put on sterile gloves
- Hold needle midway between thumb + forefinger > insert needle into skin > move fingers slightly to grasp needle hub > gradually advance needle in slight intervals + pause to notice whether a scratching sensation is felt – Scratching sensation = bowel is rubbing over the tip of the needle – Rotary or “Flicking” movement from needle = bowel contact – Periodic back and forth movement from needle in time with respiration = normal
- If no bowel is encountered > advance needle slowly to hub > until fluid is seen in hub
- Remove needle > clean site gently + apply antibiotic ointment daily for a few days
(18-22 Gauge x 1.5” Needle Abdominocentesis Method)
Needle movement:
Scratching sensation =
scratching sensation = bowel is rubbing over the tip of the needle
(18-22 Gauge x 1.5” Needle Abdominocentesis Method)
Needle movement:
Rotary or “flicking” movement from needle =
Rotary or “flicking” movement from needle = bowel contact
(18-22 Gauge x 1.5” Needle Abdominocentesis Method)
Needle movement:
Periodic back and forth movement from needle in time with respiration =
Periodic back and forth movement from needle in time with respiration = normal
Where is the insertion site for abdominocentesis in foals younger than 1 month old or very colicky foals? What needle size is used?
20 gauge x 1-1.5” needle
Caudal to xiphoid midline OR right paramedian
close to the midline
Paramedian