Clinical Techniques Flashcards
Why are NWM more challenging in regards to procedures?
Smaller body size
What is the most common site for venipuncture in the NHP? How is venipuncture performed? What is an additional option in all species?
Femoral vein. Blind in infants and smaller species, aided by anatomy of femoral triangle. Can be palpated in larger species or adults. Jugular
Where can blood be collected from adult macaques, baboons, and chimps? What are these vessels more commonly used for?
Saphenous or cephalic. Fluid administration.
Where are alternate sites of blood collection in NWM?
Saphenous and bilateral teil veins
How much blood can be taken how often? How can this limit be exceeded?
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.
What are the disadvantages of urine collection via clean waste pans or free-catch?
Bacterial contamination.
What is the preferred method for sterile urine collection?
Cystocentesis
Where can cerebrospinal fluid be collected from? How should the animal be prepared? What needles should be used?
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.
How does CSF composition vary based on collection location?
Lumbar fluid = higher concentration of total protein, albumin, and IgG, lower concentration of glucose and potassium.
Where is the location for cisterna magna CSF collection? What length of needle is typically needed?
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
What CSF collection method is most desirable? Why?
Lumbar, less risk of complications.
How any NHPs positioned for lumbar CSF collection? How is the collection site identified?
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.
Describe a skin scraping.
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.
Describe skin scrapings for Demodex and Sarcoptes.
Demodex - Deep scrapping required, may cause bleeding.
Sarcoptes - Large area sampled
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?
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
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?
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.
What type of needle may be used to collect biopsy samples from the liver? How does this compare with a Jamshidi needle?
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.
To obtain larger liver samples, what may be necessary? What are potential complications of this procedure? What should be analyzed to minimize these complications?
Surgical procedure. Gall bladder puncture and hemorrhage. Evaluate blood coagulation parameters prior to biopsy and visually monitor biopsy site to ensure hemostasis.
Why are kidney biopsies most common performed? Describe the technique. Which gauge needles provided better diagnostic samples? What is the most common complication?
Proteinuria or diagnose renal disease. Same technique as with the liver. 14 gauge preferred over 18-gauge. Hemorrhage.
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?
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.
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)?
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.
What is the most efficient method of administering fluids and therapeutics?
IV
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?
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.
What limitations are associated with SQ administration compared to IV? What site is commonly used in NHPs? What is the max volume?
Only nonirritating isotonic substances and absorption of fluids is slower. Dorsal surface. 5 mL/kg site maximum.
