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1151.e4 Phlebotomy

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the uptake of F-FDG by competing at • Patient is sedated and handled gently with • SUVs are recorded for areas of interest for
the glucose transporter, rendering the scan minimal struggle and no barking before interpretation by a radiologist and clinician.
VetBooks.ir Equipment, Anesthesia • IV catheter is placed and protected from Alternatives and Their
anesthesia.
nondiagnostic.
Relative Merits
patient manipulation.
• Generation of PET/CT images requires a
dedicated PET/CT scanner or stand-alone Possible Complications and PET/CT is an enhanced form of multidimen-
sional imaging. CT and MRI imaging can be
PET scanner with a separate CT scanner Common Errors to Avoid used instead but do not provide the functional
and computer workstation to co-register the • The primary risks to the patient are those information of PET imaging (see Video).
images after generation in two separate scans of anesthesia.
in a precise positioning device. • Scan quality can be degraded by hyperglyce- Pearls
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• Anesthesia or prolonged deep sedation is mia, severe hypoglycemia, muscular activity, • F-FDG is highly sensitive for many forms of
necessary for the scan because PET image and exposure to low temperatures requiring cancer, as well as inflammation or infection.
generation is a longer process than CT effort at thermoregulation. It is not specific for any process, and positive
scanning. Concerns about worker radiation lesions should be interpreted in light of all
safety exist if team members are required to Procedure available clinical information. If lesions are of
restrain the patient after radiopharmaceuti- • Injection activity, location, and time are uncertain significance, sampling is warranted.
cal injection, and some institutions elect to noted in the scanner workstation. • Other radiopharmaceuticals have been
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anesthetize the patient at the beginning of the • F-FDG is allowed to circulate for approxi- produced that accumulate based on charac-
entire procedure. This has the added benefit mately 45 minutes. teristics other than glucose metabolism, such
of limiting muscle movement and thereby • Patient is anesthetized before injection or as amino acid metabolism, DNA synthesis,
artifactual muscle uptake. before initial scan. or hypoxia. These are not generally available
• Patient is positioned in immobilization device for practice.
Anticipated Time such as a Vac-Loc cradle.
Total time from injection of the radiophar- • Scanning is performed with CT then PET SUGGESTED READINGS
maceutical to the completion of the scan is scans acquired Grobman M, et al: F-FDG-PET/CT as adjunctive
approximately 1 2 hours, depending on scanner diagnostic modalities in canine fever of unknown
1
speed. Slower scanners may take longer. Postprocedure origin. Vet Radiol Ultrasound 59:107-115, 2017.
• Patient is isolated in a radiation isolation Randall E, et al: Physiologic variants, benign
Preparation: Important facility until radioactive emission reaches processes, and artifacts from 106 canine and feline
Checkpoints acceptable release levels. FDG-PET/computed tomography scans. Vet Radiol
• Patient is fasted at least 12 hours. • Fluorine-18 has a half-life of 110 minutes, Ultrasound 55:213, 2014.
• Patient is rested in thermoneutral with all detectable activity decayed by AUTHOR: Jeffrey N. Bryan, DVM, MS, PhD, DACVIM
environment. approximately 20 hours after injection. EDITORS: Leah A. Cohn, DVM, PhD, DACVIM; Mark S.
• Preprocedure glucose is checked (should be • PET and CT scans are co-registered on a Thompson, DVM, DABVP
normoglycemic). computer workstation for evaluation.

Video
Phlebotomy Available

Difficulty level: ♦ • Avoid using site damaged by trauma or Preparation: Important
disease (e.g., tumor, skin infection). Checkpoints
Synonyms • Determine the number and type of collection
Venipuncture, blood draw Equipment, Anesthesia tubes required, and have them at hand.
• Alcohol • Select the preferred system (needle and
Overview and Goal • ± Clippers syringe vs. Vacutainer) and site of collection
Phlebotomy is any of the various processes • Needle and syringe system versus Vacutainer for the patient.
used to obtain blood for diagnostic testing, system ○ If more than two different tubes or 6 mL
blood transfusion, or treatment of disease. This ○ Method based on reason for blood collec- of blood are required, consider use of
chapter focuses on collection of samples for tion, volume, and sample number required Vacutainer system.
diagnostic purposes. ○ Different needle and collection systems ○ Vacutainer system maximizes sample
are used for blood donation (p. 1169) quality (e.g., less hemolysis, less platelet
Indications and apheresis clumping, fills tubes to ideal volume).
• Diagnostic testing requiring blood samples • Sample tubes (number and type based on ○ The Vacutainer system is well suited for
• Monitoring changes in patient status by planned testing) jugular venipuncture but poorly suited
blood tests • ± Gauze and wrap for use on peripheral veins.
• Blood collection for transfusion • ± Tourniquet ○ Jugular vein often is preferred site of
• Treatment of polycythemia/erythrocytosis • ± Distraction, such as canned cheese collection (preserves peripheral veins for
• Apheresis (rarely performed in veterinary • ± Sedation catheter placement; allows rapid collection
medicine) of blood).
Anticipated Time ○ Avoid jugular venipuncture in animals with
Contraindications 1-5 minutes severe thrombocytopenia or coagulopathy.
• Avoid jugular venipuncture in patients with
coagulopathy.

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