V

V



Vagal Maneuver



SYNONYMS



• Carotid sinus massage

• Ocular pressure

• Valsalva maneuver


OVERVIEW AND GOALS


A physical manipulation that temporarily increases parasympathetic tone, mainly for diagnostic—and occasionally therapeutic—cardiac rhythm effects



INDICATIONS


Tachycardia in which the rate is so rapid that it is unclear on the electrocardiogram (ECG) whether the rhythm is ventricular or supraventricular (e.g., heart rate is >260 bpm)



CONTRAINDICATIONS



• Ocular disease (for ocular pressure)

• Disorders of the ventral neck (for carotid sinus massage)

• Bradycardia, including the bradycardia-tachycardia syndrome (sick sinus syndrome)


EQUIPMENT, ANESTHESIA


No anesthetic requirement; procedure is performed when the animal is awake. Procedure requires ECG machine with printer to assess and record initial cardiac rhythm and to record effect of vagal maneuver.



ANTICIPATED TIME


<1 minute



PREPARATION: IMPORTANT CHECKPOINTS


A printed ECG tracing of the rhythm prior to the vagal maneuver is necessary.



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 supraventricular 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.

• The vagal maneuver is applied, with the ECG printing continuously. The ECG paper should be marked at the time of onset of the vagal maneuver. Usually, only one maneuver is performed. The ECG should be allowed to continue to run (printing) throughout the duration of the vagal maneuver and for at least 15 seconds after its termination.


image VAGAL MANEUVER Placement of fingers for performing carotid sinus massage in a dog.

OCULAR PRESSURE:



• The patient’s eyelids are closed, and using the thumb and middle finger of the same hand, both globes are depressed caudally into the orbit.

• A small, smooth massaging motion may be applied to the eyes along with the direct pressure.

• The degree of pressure should be sufficient that the eyes are substantially retracted caudally without, however, provoking any sign of discomfort or resentment. The exact extent of retraction will vary depending on orbit shape and size.

• Pressure is maintained until a substantial decrease in heart rate is noted and the rhythm can be identified or until the maneuver has been applied for 15 seconds.

CAROTID SINUS MASSAGE:


• The target area is the base of the internal carotid artery, which is not palpable as such but is located dorsocranially to the larynx, medial to the angle of the mandible.
○ For localization: the larynx is palpated using the thumb and forefinger. The thumb and forefinger are moved dorsally and cranially from the larynx until resting in the natural depression medial to the angle of the mandible and ventral to the occipital bone.

• Gentle, pincer-like pressure is applied in this area with the thumb and forefinger.

• Pressure is maintained, and a small, smooth, circular massaging motion may be performed.

• The pressure exerted is often sufficient to elicit a gag reflex but should not be so great as to cause discomfort or resentment.

• Pressure is maintained until a substantial decrease in heart rate is noted and the rhythm can be identified or until the maneuver has been applied for 15 seconds.


POSTPROCEDURE



• A vagal maneuver can routinely be terminated abruptly.

• Failure to slow tachycardia with a vagal maneuver should prompt a search for the tachycardia’s possible causes, including anxiety/stress of hospitalization, respiratory compromise, structural cardiac disease, and systemic illness.


ALTERNATIVES AND THEIR RELATIVE MERITS


Pharmacologic slowing of tachycardias, such as with injectable propranolol, verapamil, or adenosine, should only be considered once the aforementioned possible inciting factors have been ruled out or addressed.


AUTHOR: ETIENNE CÔTÉ



Vaginal Palpation in the Bitch



SYNONYM


Digital vaginal examination



OVERVIEW AND GOALS


Minimally invasive digital examination of the vagina to evaluate the vaginal anatomy. Possible lesions in bitches include:


• Vaginal strictures

• Vaginal tumors

• Trauma during breeding

• Congenital anatomic anomalies


INDICATIONS



• Vaginal discharge

• Poor breeding experience

• Urinary incontinence (urine pooling)

• Dystocia


CONTRAINDICATIONS


There are relatively few contraindications to this procedure.



• If infection of the reproductive tract is a consideration:
○ Vaginal culture should be taken first.

○ Culture is followed by vaginal cytologic analysis before a digital examination is performed.


EQUIPMENT, ANESTHESIA



• Minimal restraint usually required

• Antiseptic cleanser

• Sterile exam glove

• Sterile water-soluble lubricant


ANTICIPATED TIME


With a cooperative bitch, the procedure should take less than 5 minutes, from gentle cleansing of the vulvar lips to finishing the exam.



POSSIBLE COMPLICATIONS AND COMMON ERRORS TO AVOID



• Urethral opening lies on the ventral surface of the vestibule and should be avoided:
○ This is not difficult if the finger is passed up to the vestibulovaginal junction perpendicularly to the ground in the standing bitch.

• Vestibulovaginal junction is one barrier to the entrance of the uterus and should not be mistaken for the cervix or a stricture:
○ The canine vagina is very long (up to 12 inches [29 cm] in giant-breed dogs), and thus the cervix is unlikely to be palpated on digital examination of the vagina.

○ The junction acts a barrier to pathogens and will be narrower than the vestibule or vagina. If the examiner proceeds slowly, he or she should be able to pass the finger beyond the junction in most bitches (depending on the size of the bitch and the size of the finger).


PROCEDURE



• Animal should be restrained in standing position.

• Vulvar lips should be gently wiped with a mild antibacterial cleanser.

• Examiner should wear sterile gloves.

• After coating the gloved index finger with the sterile lubricant, the finger is passed into the vulva and turned directly upward (90° angle to the floor in the standing animal). The upward direction is important so the urethral opening is avoided.

• When the finger cannot go any farther dorsally, it is turned directly cranially (parallel to the floor) and advanced over the ischium and into the vaginal vault:
○ As the finger passes over the ischium into the vagina, there may be a slight tightening at the vestibulovaginal junction. Depending on the size of the bitch and the size of the hand, most fingers should pass through this junction.

○ If the finger is well lubricated and it does not pass this point, a vaginal stricture should be considered.


image VAGINAL PALPATION Anatomic relationship of vestibule and vagina in the bitch. Dorsal is toward top of image, cranial to left.


ALTERNATIVES AND THEIR RELATIVE MERITS



• Speculum examination (vaginoscopy; see p. 1361) may be performed for the visualization of the vaginal walls and vault:
○ Inflamed walls in vaginitis cases

○ Urine on the floor of the vagina in urine-pooling disorders

○ Evidence of trauma in difficult breeding

○ Evaluation of vaginal folds and mucosa for timing of estrus

• Vaginoscopy with an endoscope to visualize vagina and potentially the cervix

AUTHOR: CAROL A. MCCLURE



Vaginoscopy



OVERVIEW AND GOAL


Visual inspection of the surface of the vaginal mucosa. This can be accomplished through a plastic or metal speculum, or is most rewarding with a fiberoptic endoscope.



INDICATIONS



• Examining the physical changes associated with hormonal events of the canine reproductive cycle

• Evaluating abnormal conditions of the caudal reproductive tract (vestibule, vagina, and caudal cervix). Common disorders of the caudal reproductive tract include vaginal septa, vestibulovaginal stenosis (strictures), paramesonephric septal remnants, tumors, foreign bodies, lymphoid inflammation or hyperplasia, and ectopic ureters.

• To facilitate catheterization of the cervix for intrauterine artificial insemination


EQUIPMENT, ANESTHESIA


Bitches in estrus tolerate vaginal procedures well; bitches in early proestrus or anestrus may need sedation or even general anesthesia, depending on the medical reasons to perform the vaginoscopy.


Equipment:


• Endoscope or speculum: if using a rigid endoscope, its size should be compatible with the size of the bitch.

• Sterile water-soluble lubricant

• Light source if not integral part of endoscope/speculum

• Swabs

• Microscope slides


image VAGINOSCOPY Endoscopic view of the canine vagina in midestrus.


ANTICIPATED TIME


5-20 minutes



PREPARATION: IMPORTANT CHECKPOINTS



• Be sure to apply lubricant copiously to the endoscope before introducing it.

• Position: if in estrus, most bitches will remain standing while vaginoscopy is being performed, especially if transcervical insemination is to be performed. In anestrous or spayed dogs, care should be taken to not traumatize the vaginal walls, especially if a rigid endoscope is being used.
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Jul 24, 2016 | Posted by in SMALL ANIMAL | Comments Off on V

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