Page 2394 - Cote clinical veterinary advisor dogs and cats 4th

1183.e4 Vagal Maneuver

Vagal Maneuver
VetBooks.ir

• The vagal maneuver is applied, with the
Difficulty level: ♦♦
ECG printing continuously. The ECG paper angle of the mandible and ventral to the
occipital bone.
Synonyms should be marked at the time of onset of the • Gentle, pincer-like pressure is applied in this
• Carotid sinus massage vagal maneuver. Usually, only one maneuver area with the thumb and forefinger.
• Ocular pressure is performed at a time. The ECG should • Pressure is maintained, and a small, smooth,
• Valsalva maneuver be allowed to continue to run (printing) circular massaging motion may be performed.
throughout the duration of the vagal • The pressure exerted is often sufficient to
Overview and Goal maneuver and for at least 15 seconds after its elicit a gag reflex but should not be so great
A physical manipulation that temporarily termination. as to cause discomfort or resentment.
increases parasympathetic tone, mainly for Ocular pressure: • Pressure is maintained until a substantial
diagnostic and occasionally for therapeutic • The patient’s eyelids are closed, and using the decrease in heart rate is noted and the rhythm
cardiac rhythm effects thumb and middle finger of the same hand, can be identified or until the maneuver has
both globes are depressed caudally into the been applied for 15 seconds.
Indications orbit.
Tachycardia in which the rate is so rapid that • A small, smooth massaging motion may be Postprocedure
it is unclear on the electrocardiogram (ECG) applied to the eyes along with the direct • A vagal maneuver can routinely be terminated
whether the rhythm is ventricular or supraven- pressure. abruptly.
tricular (e.g., heart rate is > 260 beats/min) • The degree of pressure should be sufficient • Failure to slow tachycardia with a vagal
that the eyes are substantially displaced maneuver should prompt a search for the
Contraindications caudally without provoking any sign of tachycardia’s possible causes, including
• Ocular disease (for ocular pressure) discomfort or resentment. The exact extent anxiety/stress of hospitalization, respiratory
• Disorders of the ventral neck (for carotid of retraction will vary depending on orbit compromise, structural cardiac disease, and
sinus massage) shape and size. systemic illness.
• Bradycardia, including sinus node dysfunc- • Pressure is maintained until a substantial
tion (sick sinus syndrome) decrease in heart rate is noted and the rhythm Alternatives and Their
can be identified or until the maneuver has Relative Merits
Equipment, Anesthesia been applied for 15 seconds. Pharmacologic slowing of tachycardias, such
• No anesthetic requirement; procedure is Carotid sinus massage: as with injectable diltiazem or esmolol, should
performed when the animal is awake. • The target area is the base of the internal be considered only after the aforementioned
• Procedure requires ECG machine with printer carotid artery, which is not palpable but is possible inciting factors have been ruled out
to assess and record initial cardiac rhythm located dorsocranially to the larynx, medial or addressed.
and to record effect of vagal maneuver. to the angle of the mandible.
○ For localization: the larynx is palpated Reproduced from the third edition in
Anticipated Time using the thumb and forefinger. The unabridged form.
<1 minute thumb and forefinger are moved dorsally AUTHOR: Etienne Côté, DVM, DACVIM
and cranially from the larynx until resting EDITORS: Leah A. Cohn, DVM, PhD, DACVIM; Mark S.
Preparation: Important in the natural depression medial to the Thompson, DVM, DABVP
Checkpoints
A printed ECG tracing of the rhythm should
be obtained before the vagal maneuver.
Possible Complications and
Common Errors to Avoid
• Inadequate vagal response: subjectively,
carotid sinus massage appears to be more
effective than ocular pressure in some patients
and vice versa in others, but some supra-
ventricular tachycardias (and essentially all
cases of ventricular tachycardia) are resistant
to both.
• Concerns regarding vagal maneuver: related
harm due to carotid artery atherosclerosis
is based on human cardiology but is not
expected to be relevant to small animal
medicine.
Procedure
• Patient may be standing or recumbent.
• ECG leads are connected, and a good ECG
signal should be seen.
• The prevagal-maneuver ECG is traced/
printed; about 20-30 seconds of tracing
should be recorded. VAGAL MANEUVER Placement of fingers for performing carotid sinus massage in a dog.

www.ExpertConsult.com