Clinical Techniques

Question 1

Why are NWM more challenging in regards to procedures?

Answer 1

Smaller body size

Question 2

What is the most common site for venipuncture in the NHP? How is venipuncture performed? What is an additional option in all species?

Answer 2

Femoral vein. Blind in infants and smaller species, aided by anatomy of femoral triangle. Can be palpated in larger species or adults. Jugular

Question 3

Where can blood be collected from adult macaques, baboons, and chimps? What are these vessels more commonly used for?

Answer 3

Saphenous or cephalic. Fluid administration.

Question 4

Where are alternate sites of blood collection in NWM?

Answer 4

Saphenous and bilateral teil veins

Question 5

How much blood can be taken how often? How can this limit be exceeded?

Answer 5

10-15% every 2 weeks. If all blood components are not required, samples can exceed the calculated limits if the plasma or red cells that were collected are returned to the animal after separation, along with fluid supplementation.

Question 6

What are the disadvantages of urine collection via clean waste pans or free-catch?

Answer 6

Bacterial contamination.

Question 7

What is the preferred method for sterile urine collection?

Answer 7

Cystocentesis

Question 8

Where can cerebrospinal fluid be collected from? How should the animal be prepared? What needles should be used?

Answer 8

Cisterna magna or lumbar area. Animal must be anesthetized and the area surgically prepared. Spinal needles or short bevel needles of appropriate size and length.

Question 9

How does CSF composition vary based on collection location?

Answer 9

Lumbar fluid = higher concentration of total protein, albumin, and IgG, lower concentration of glucose and potassium.

Question 10

Where is the location for cisterna magna CSF collection? What length of needle is typically needed?

Answer 10

Junction of line that bisects cranial wings of the atlas and line extending caudal from the external occipital protuberance. 1.5 - 2 in needle in macaques, 2-3 in needle in chimps

Question 11

What CSF collection method is most desirable? Why?

Answer 11

Lumbar, less risk of complications.

Question 12

How any NHPs positioned for lumbar CSF collection? How is the collection site identified?

Answer 12

Lateral recumbency or sitting position with slight flexion of spine to facilitate widening of intervertebral space. Horizontal line between both iliac crests with bisect intervertebral space that should be entered. If difficulty entering, either of the two spaces above can serve as sites.

Question 13

Describe a skin scraping.

Answer 13

Abrading the skin with a scalpel blade, transferring the debris to a drop of mineral oil on a glass slide, and observing the debris microscopically to detect ectoparasites.

Question 14

Describe skin scrapings for Demodex and Sarcoptes.

Answer 14

Demodex - Deep scrapping required, may cause bleeding.
Sarcoptes - Large area sampled

Question 15

Should the skin be surgically prepared prior to cutaneous punch biopsies? What preparation should be performed? When is aseptic prep indicated? What should be administered at the site?

Answer 15

Not in immune competent patients, as it can remove diagnostic indicators such as parasite, micro-organisms, and the stratum corneum. Gentle hair clipping typically sufficient. Aseptic prep only when entire mass is being removed. 1-2% lidocaine

Question 16

What may be a better biopsy technique when a large, full-thickness skin biopsy is required? What stages of the lesion should be sampled? How should the biopsy be performed?

Answer 16

Cutaneous wedge biopsy. Sample different stage of the lesion with normal tissue. Performed under anesthesia and closed with sutures. Multiple samples increase likelihood of a diagnostic sample.

Question 17

What type of needle may be used to collect biopsy samples from the liver? How does this compare with a Jamshidi needle?

Answer 17

Menghini needles. Both are hollow needles. Menghini has a sharp tip and is used specifically for the liver. Jamshidi has a tapered cutting edge specifically for bone marrow.

Question 18

To obtain larger liver samples, what may be necessary? What are potential complications of this procedure? What should be analyzed to minimize these complications?

Answer 18

Surgical procedure. Gall bladder puncture and hemorrhage. Evaluate blood coagulation parameters prior to biopsy and visually monitor biopsy site to ensure hemostasis.

Question 19

Why are kidney biopsies most common performed? Describe the technique. Which gauge needles provided better diagnostic samples? What is the most common complication?

Answer 19

Proteinuria or diagnose renal disease. Same technique as with the liver. 14 gauge preferred over 18-gauge. Hemorrhage.

Question 20

When is biopsy of lymph nodes indicated? How are lymph node biopsies collected? What are the most accessible lymph nodes in NHPs? During exploratory surgery, excisional biopsies are most frequently done on what lymph nodes?

Answer 20

Lymph node enlargement, generalized lymphadenopathy, or suspicion of tumor metastasis. Collected by needle aspiration, punch biopsy, and excisional biopsy. Most accessible are the axillary and superficial inguinal lymph nodes. During exploratory surgery, excisional biopsies most frequently done on mesenteric and iliac lymph nodes.

Question 21

What is the most common technique to sample bone marrow? What is the preferred site and alternate sites? What occurs in smaller species (marmosets, Aotus, and Saimiri)?

Answer 21

Needle aspiration. Iliac crest preferred, trochanter of femur, tibial tuberosity, greater tubercle of proximal humerus, sternum, rib, and ischial tuberosity can be used. In smaller species, size of marrow cavity may be small and minimal aspiration will rupture vasculature, resulting in peripheral blood sample rather than bone marrow.

Question 22

What is the most efficient method of administering fluids and therapeutics?

Answer 22

IV

Question 23

What sites are most commonly used for IV administration? Why? What other methods of securing the catheter may be used? What might be the best for long-term access?

Answer 23

Cephalic or saphenous. Needles or catheters can be more easily secured with tape at these sites and leaves femoral veins accessible for blood collection or procedures needing venous access. Catheter systems in combination with limb immobilization by splint and bandage or lightweight casting material or jacket with tether or backpack equipment. VAP to reduce number of needle sticks and facilitate multiple sampling timepoints.

Question 24

What limitations are associated with SQ administration compared to IV? What site is commonly used in NHPs? What is the max volume?

Answer 24

Only nonirritating isotonic substances and absorption of fluids is slower. Dorsal surface. 5 mL/kg site maximum.

Question 25

How fast is IM absorption? Why? What limitations are there? What are potential side effects?

Answer 25

Rapid due to abundant vascular structures in muscle tissue. Smaller volumes and may be more difficult to administer substances via this route in smaller NHPs. Side effects depend on substance, can include muscle necrosis and nerve damage resulting in paresis or paralysis.

Question 26

When is intraosseous administration needed? What is the preferred site?

Answer 26

In debilitated, hypotensive animals when venous access is limited. Most accessible site in owl monkeys in the trochanteric fossa of femur, proximal anterior tibia common site in larger species.

Question 27

How is the site prepped for intraosseous administration? How is fluid administered? What is a limitation? How does fluid enter the system? What are potential complications?

Answer 27

Prepared aseptically and skin and periosteum are anesthetized with lidocaine. 18-25 gauge needle introduced aseptically into the medullary cavity. In small NHPs, a hypodermic needle may be used, but larger species will require a spinal needle or bone marrow needle with stylet. Fluid administered via standard infusion set, flow limited as bone marrow cavity cannot expand to accept increased flow. Fluid enters central venous circulation from the medullary venous sinuses. Osteomyelitis, iatrogenic fracture, and growth plate injury.

Question 28

How common is IP injection in NHP? Which primate species is it typically used? When? In what volumes? How does it compare to IV injection?

Answer 28

Rarely used. Can be used in smaller NHP to administer large volumes of fluid (10 mL/kg max) when IV administration not possible. Slower absorption than IV as absorption occurs primarily via mesenteric vessels which closely resembles the pharmacokinetics of substances administered orally.

Question 29

How is nasogastric intubation used? What medical procedures is it important for? How does implementation differ between NWM and OWM?

Answer 29

Rapid and effective means of delivering oral fluids and medication. Used for relieving acute gastric dilation (bloat) and culture of gastric lavage for mycobacterial infection. Nares of WM are laterally flared, need lateral insertion. OWM nares have downward orientation, requires an upward insertion technique.

Question 30

How far should restraint gloves extend?

Answer 30

Beyond the elbow.

Question 31

Generally, hand capture can be performed on NHPs that are not larger than what?

Answer 31

A young adult female rhesus monkey.

Question 32

When are restraint nets appropriate? Up to what weight?

Answer 32

Personnel need to maintain a safe distance from the animal being captured. Once netted, hand restrained or given anesthetic. Capturing escaped animals or retrieving individual animals in social groups. 3.5 kg

Question 33

What are the advantages of the pole-and-collar method?

Answer 33

Reduction in opportunity for personnel and animal injury and decreased level of stress for NHP (once acclimated)

Question 34

What do tether and vest restraint allow? Describe the process. How long does training take? What are the advantages?

Answer 34

Continuous physiologic monitoring, biological sampling, and infusion of drugs without multiple restraint episodes. Tether device typically a nylon-mesh vest or jacket and flexible tether tube with swivel. Trained within 1 week. Advantages include less animal stress, less handling, and less risk of injury to caregivers.

Question 35

Pole syringes can be used at distances up to what? CO2-powered pistols? CO2-powered rifles?

Answer 35

Pole syringe: 2m
Pistols: <20 m
Rifle: >20m

Question 36

When CO2-powered devices are used, the risk of animal injury increases:

Answer 36

As the size and distance of the device decreases.

Question 37

What are complications of using too powerful a restraint device at too short a distance? What is an alternative to CO2-powered devices?

Answer 37

Bone fractures and internal organ injury. Blowpipes work well at ranges up to 15m with less risk of injury.

Question 38

What is the most commonly used restraint drug for NHP? How does dose differ between OWM and NWM?

Answer 38

Ketamine hydrochloride.
OWM = 5-20 mg/kg
NWM = Higher dose, 10-30 mg/kg needed

Question 39

What other drugs/drug combos can be used for anesthesia?

Answer 39

Ketamine-xylazine at 3:1 ratio
Telazol (tiletamine hydrochloride/zolazepam hydrochloride

Question 40

Procedures of what length should use isoflurane? What are advantages to its use? What are differences of sevoflurane and desflurane?

Answer 40

Greater than 45 minutes.
Inexpensive, faster induction and recovery time than halothane. Less catecholamine-sensitizing and cardiodepressive properties, so preferred for hepatic and renal patients.
Sevoflurane has a lower solubility coefficient than iso, resulting in faster recovery. Can be too quick, and should be tapered for a smooth recovery.
Desflurane produces most rapid induction and recovery, but high cost and vapor pressure make its use less common.

Question 41

Describe blunting or disarming of the canine teeth of primates. Why was it performed? Is it acceptable today? For what reasons may it be practiced today? What does the AVMA position statement say?

Answer 41

Previously considered an acceptable method to reduce risk of injury to social group members and personnel. Under AWA, Animal Care Policy #3, non-medical canine tooth removal or reduction that exposes pulp cavity is not appropriate vet care. In some behavioral or breeding situations may be acceptable to reduce canine teeth as long as pulp cavity is not exposed. 2007 statement stating that removal of canine teeth must be medically or scientifically justified, or justified by animal or human safety concerns. Recommends alterations.