Page 2161 - Cote clinical veterinary advisor dogs and cats 4th

1080 Cerebrospinal Fluid Collection

• CPR requires an excellent team performance; SUGGESTED READING AUTHORS: Manuel Boller, Dr. med. vet., MTR,
conduct mock codes and debriefings. Fletcher DJ, et al: RECOVER evidence and DACVECC; Daniel J. Fletcher, PhD, DVM, DACVECC
EDITORS: Leah A. Cohn, DVM, PhD, DACVIM; Mark S.
VetBooks.ir within hours after ROSC. Neurologic prog- knowledge gap analysis on veterinary CPR. Part 7: Thompson, DVM, DABVP
• Do not expect animals to return to normal
Clinical guidelines. J Vet Emerg Crit Care 22(suppl
nostication is difficult and not well defined
1):S102-S131, 2012.
for small animals. Neurologic progress should
be assessed over several days before arriving
at a definitive grave neurologic prognosis.

Cerebrospinal Fluid Collection Client Education
Sheet

Difficulty level: ♦♦ • An assistant to position the animal and parallel to the table. Care must be taken to
stabilize the animal’s head and neck not overflex the neck, which could result
Synonyms • Level stationary or locked table in obstruction of the endotracheal tube or
Spinal tap, CSF tap compress the jugular veins and increase intra-
Anticipated Time cranial pressure. For the head to be parallel
Overview and Goal About 30 minutes of anesthesia to the table, the assistant must hold the nose
• To safely collect an uncontaminated sample slightly elevated from the table.
of cerebrospinal fluid (CSF) from an animal Preparation: Important • The assistant positions the dorsal aspect of
with suspected central nervous system (CNS) Checkpoints the neck at the edge or slightly over the edge
disease • Performed preferably after advanced imaging of the table.
• CSF analysis is the single most valuable has ruled out noninflammatory processes • The clinician should sit on a stool or kneel
diagnostic test for evaluating inflamma- (neoplasia, malformation, vascular disorders) to be at eye level with the animal’s head.
tory CNS disorders, and it aids in the and obvious increased intracranial pressure Landmarking and puncture:
diagnosis of other encephalopathies and (coning and caudal displacement of the • The right-handed clinician places the left
myelopathies. cerebellum, flattening of gyri, loss of sulci) thumb on the right wing of the animal’s
• Make arrangements for laboratory transport atlas and the left middle/ring finger on the
Indications within 30 minutes of collection, or have left wing of the atlas.
• Clinical signs consistent with CNS or nerve in-house analysis equipment prepared and • The left index finger is used for identifying the
root dysfunction calibrated. midline by palpating the occipital protuber-
• Monitoring treatment efficacy of confirmed • If immediate analysis of the CSF is not ance and the dorsal spine of C2, drawing an
inflammatory CNS disease possible, special preservation techniques may invisible line between these points.
• Intrathecal administration of contrast mate- be required (prior laboratory consultation is ○ Many cats and toy-breed dogs do not
rial (myelography) or medications recommended). have a well-defined occipital protuberance;
• Warn owners of hair clipping and low risk instead, the spine of C2 should be used
Contraindications of complications. Complications associated as the sole landmark for identifying the
Absolute: with the procedure, although rare, can be midline.
• Increased intracranial pressure (depressed fatal. • The orientation of the needle’s path should
mental status, bradycardia, hypertension, be parallel to the table’s surface and toward
miosis, anisocoria) Possible Complications and the angle of the animal’s mandible.
• Any condition in which general anesthesia Common Errors to Avoid • For dogs, using the right hand, the needle
is contraindicated • Blood contamination of the sample with stylet in place is inserted through the
Relative: • Iatrogenic neuronal injury skin along the midline just cranial to the
• Advanced imaging results that identify a • Brain herniation wings of the atlas.
noninflammatory disease process consistent • Inadequate sample volume • In cats, the skin is often tough, and the
with the animal’s clinical signs distance between the skin and subarachnoid
• Coagulopathy Procedure space is very small. Although the same point
CEREBELLOMEDULLARY APPROACH of insertion is identified, the skin should be
Equipment, Anesthesia • General anesthesia and intubation tented before inserting the needle through
• General anesthesia and endotracheal • Preparation and positioning for centesis from the skin into the subcutaneous tissues.
intubation the cerebellomedullary cistern (preferred for • The needle is directed through subcutaneous
• A few 20- or 22-gauge, 1 2 -inch spinal ease and lower risk of blood contamination) fat and muscle toward the subarachnoid
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needles ( 2 2 -inch or 3 2 -inch needles ○ Shave and aseptically prepare the skin from space, taking care to avoid lateral, caudal,
1
1
may be needed for large dogs or for lumbar the occipital protuberance to the spine of or cranial deviation of the spinal needle.
approach) C3 and to the base of each pinna. • Occasionally, a loss of resistance to the needle
• Hair clippers • Don sterile gloves. insertion is felt as the needle passes through
• Surgical scrub solution, isopropyl alcohol, • Patient in right lateral recumbency (right- the fascial planes of the muscle and, eventu-
and gauze handed clinician) or left lateral (left-handed ally, the dorsal atlantooccipital membrane;
• Sterile surgical gloves clinician) this so-called pop is not reliable and should
• Sterile collection tubes (do not use tubes • An assistant holds the head with the neck not be used as an indicator of appropriate
containing EDTA [lavender-top tubes]) flexed at a 90° angle and the head and neck depth of the needle.
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