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VAGAL MANEUVERS
When a patient suffers sinus, atrial, or junctional tachyarrhythmias, vagal maneuvers—the Valsalva maneuver and carotid sinus massage—can slow the heart rate. These maneuvers work by stimulating parasympathetic nerve endings, which respond as they would to an increase in blood pressure. They send this message to the brainstem, which in turn stimulates the parasympathetic nervous system to increase vagal tone and decrease the heart rate. Usually performed by a health care provider, vagal maneuvers may also be performed by an advanced practice nurse under a health care provider’s supervision.
In the Valsalva maneuver, the patient holds his or her breath and bears down, raising the intrathoracic pressure. When this pressure increase is transmitted to the heart and great vessels, venous return, stroke volume, and systolic blood pressure decrease. Within seconds, the baroreceptors respond to the changes by increasing the heart rate and causing peripheral vasoconstriction. When the patient exhales at the end of this maneuver, blood pressure rises to its previous level. This increase, combined with the peripheral vasoconstriction caused by bearing down, stimulates the vagus nerve, decreasing the heart rate.
There is also a modified Valsalva maneuver. Patients with supraventricular tachycardia (SVT) perform straining maneuver while in a semirecumbent position, then immediately lie supine with their legs raised to 45 degrees for 15 seconds before returning to the semirecumbent position. The purpose of this postural modification is to boost relaxation phase venous return and vagal stimulation.
In carotid sinus massage, manual pressure applied to the left or right carotid sinus slows the patient’s heart rate. The patient’s response to carotid sinus massage depends on the type of arrhythmia. If the patient has sinus tachycardia, the patient’s heart rate will slow gradually during the procedure and speed up again after it. In atrial tachycardia, the arrhythmia may stop, and the heart rate may remain slow. With atrial fibrillation or flutter, the ventricular rate may not change; atrioventricular block may even worsen. Nonparoxysmal tachycardia and ventricular tachycardia will not respond to carotid sinus massage.
Essential Documentation
The nurse should record the date and time of the procedure, who performed it, and why it was necessary. Note the patient’s response, any complications, and the interventions taken. If possible, obtain a rhythm strip before, during, and after the procedure.
Vagal Maneuvers
VENTRICULAR ASSIST DEVICE
A temporary life-sustaining treatment for the failing heart, the ventricular assist device (VAD) diverts systemic blood flow from a diseased ventricle into a centrifugal pump, thus temporarily reducing ventricular work, which allows the myocardium to rest and contractility to improve. The VAD functions somewhat like an artificial heart. The major difference is that the VAD assists the heart, whereas the artificial heart replaces it.
The permanent VAD is implanted in the patient’s chest cavity, although it still provides only temporary support. The device receives power through the skin by a belt of electrical transformer coils (worn externally as a portable battery pack). It can also be operated by an implanted, rechargeable battery for short periods of time.
Candidates for the VAD include patients with massive myocardial infarction, end stage heart failure, irreversible cardiomyopathy, acute myocarditis, an inability to be weaned from cardiopulmonary bypass, valvular disease, bacterial endocarditis, or heart transplant rejection. The device may also be used in patients awaiting a heart transplant.
Essential Documentation
The nurse should record the date and time of the entry. Note the patient’s condition after the insertion of the VAD. Record the results of the cardiopulmonary findings (including hemodynamic measurements) as well as neurologic and renal assessments. Document pump adjustments and the patient’s response. Chart signs and symptoms of poor perfusion and ineffective pumping (e.g., arrhythmias, hypotension, slow capillary refill, cool skin, oliguria or anuria, or anxiety and restlessness), pulmonary embolism (such as dyspnea, chest pain, tachycardia, productive cough, or low-grade fever), and stroke or neurologic deficits.
Record the time that the health care provider was notified of complications, the provider’s name, orders given, nursing interventions, and the patient’s response. Document any drugs given (such as heparin); the dosage, frequency, and route; and the patient’s response. Record the appearance of the cannula insertion site, site care, and dressing changes. Document all patient teaching and emotional support provided. Patient teaching may be recorded on a patient-teaching flow sheet. Use flow sheets to record frequent assessments, including vital signs, intake and output, intravenous therapy, hemodynamic parameters, and laboratory test values (e.g., complete blood count and coagulation studies).
Ventricular Assist Device (VAD)