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38 Cards in this Set
- Front
- Back
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What are the major indications for CABG?
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Alleviation of angina that cannot be controlled with medication or PCI
Treatment of left main coronary artery stenosis or multivessel CAD Prevention and treatment of MI, dysrhythmias, or heart failure Treatment for complications from an unsuccessful PCI |
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The recomendation for CABG is determined by what factors?
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the number of diseased coronary vessels
the degree of left ventricular dysfunction the presence of other health problems the patient's symptoms and any previous treatment. |
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For a patient to be considered for CABG, the coronary arteries to be bypassed must have approximately a _____ occlusion (____ if in the left main coronary artery).
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70%
60% |
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What vessel is commonly used for CABG
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saphenous vein, followed by the lesser saphenous vein
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What is a common advese effect of vein removal?
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Edema in the extremity from which the vein was taken. The degree of edema varies and usually diminshes over time.
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What happens to the saphenous veing grafts within 5 to 10 years of a CABG?
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Athersclerotic changes
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Why are arterial grafts perfered to venous grafts?
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Arterial grafts are preferred to venous grafts because they do not develop atherosclerotic changes as quickly and remain patent longer.
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What procedures mechanically circulates and oxygenates blood for the body while bypassing the heart and lungs?
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Cardiopulmonary Bypass (CPB or external circulation)
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What maintains perfusion to body organs and tissues and allows the surgeon to complete the anastomoses in a motionless, bloodless surgical field?
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CPB
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How is the heart stopped for CPB?
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An injections of cardioplegia solution, which is high in K+ into the coronary arteries.
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What is the most common complication of cardiac surgery?
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hypovolemia
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What are some causes of hypovolemia afer cardiac surgery?
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Net loss of blood and intravascular volume
Surgical hypothermia (As the reduced body temperature rises after surgery, blood vessels dilate, and more volume is needed to fill the vessels.) Intravenous fluid loss to the interstitial spaces because surgery and anesthesia make capillary beds more permeable Increased heart rate, arterial hypotension, low pulmonary artery wedge pressure (PAWP), and low central venous pressures (CVP) often are seen |
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How is hypovolemia treated after cardiac surgery?
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Fluid replacement may be prescribed. Replacement fluids include: colloid (albumin, hetastarch), packed red blood cells, or crystalloid solution (normal saline, lactated Ringer's solution).
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What are some causes of persistent bleeding following cardiac surgery?
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Cardiopulmonary bypass may cause platelet dysfunction, and hypothermia alters clotting mechanisms
Surgical trauma causing tissues and blood vessels to ooze bloody drainage Intraoperative anticoagulant (heparin) therapy Postoperative coagulopathy may also result from liver dysfunction and depletion of clotting components |
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What assessments/interventsion should be done for persistent bleeding following cardiac surgery?
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Accurate measurement of wound bleeding and chest tube blood is essential. Bloody drainage should not exceed 200 mL/h for the first 4 to 6 hours. Drainage should decrease and stop within a few days, while progressing from sanguineous to serosanguineous and serous drainage.
Protamine sulfate may be administered to neutralize unfractionated heparin; vitamin K and blood products may be used to treat hematologic deficiencies. If bleeding persists, the patient may return to the operating room. |
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What is fluid and clots accumulate in the pericardial sac, which compresses the heart, preventing blood from filling the ventricles?
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Cardiac Tamponade
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What are the signs and symtoms of cardiac tamponade?
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Signs and symptoms include arterial hypotension, tachycardia, muffled heart sounds, decreasing urine output, and ↑ CVP. Additional signs and symptoms: arterial pressure waveform demonstrating a pulsus paradoxus (decrease of more than 10 mm Hg during inspiration) and decreased chest tube drainage (suggesting that the drainage is trapped or clotted in the mediastinum).
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What assessments or interventions may be done for cardiac tamponade
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The chest drainage system is checked to eliminate possible kinks or obstructions in the tubing.
Drainage system patency may be reestablished by milking the tubing (taking care not to strip the tubing, creating negative pressure within the chest, which may harm the surgical repair or trigger a dysrhythmia). Chest x-ray may show a widening mediastinum. Emergency medical management is required; may include pericardiocentesis or return to surgery. |
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Descripe fluid overload following cardiac surgery.
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High PAWP, CVP, and pulmonary artery diastolic pressures as well as crackles indicate fluid overload
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What are some interventions for fluid overload following cardiac surgery?
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Diuretics are prescribed and the rate of IV fluid administration is reduced.
Alternative treatments include continuous renal replacement therapy and dialysis. |
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What is low body temperature leads to vasoconstriction, shivering, and arterial hypertension?
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hypothermia
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How is hypothermia treated following cardiac surgery?
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Patient is rewarmed gradually after surgery, decreasing vasoconstriction
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What results from postoperative vasoconstriction. It may stretch suture lines and cause postoperative bleeding. The condition may be transient.
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Hypertension
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What are some possible interventions for HTN following cardiac surgery?
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Vasodilators (nitroglycerin [Tridil], nitroprusside [Nipride, Nitropress]) may be used to treat hypertension. Administer cautiously to avoid hypotension
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An increased heart rate is common with perioperative volume changes. Uncontrolled atrial fibrillation commonly occurs during the first few days postoperatively. What is are these known as?
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Tachdydysythmias
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What might be done for a post cardiac surgery patient experiencing tachdysrhythmias?
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If a tachydysrhythmia is the primary problem, the heart rhythm is assessed and medications (eg, adenosine [Adenocard, Adenoscan], amiodarone [Cordarone], digoxin [Lanoxin], diltiazem [Cardizem], esmolol [Brevibloc], lidocaine [Xylocaine], procainamide [Pronestyl]), may be prescribed. Patients may be prescribed antiarrhythmics before CABG to minimize the risk of postoperative tachydysrhythmias.
Carotid massage may be performed by a physician to assist with diagnosing or treating the dysrhythmia. Cardioversion and defibrillation are alternatives for symptomatic tachydysrhythmias. For patients who cannot attain normal sinus rhythm, an alternate goal may be to establish a stable rhythm that produces a sufficient cardiac output. |
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What complication following cardiac surgery is a decreased heart rate?
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bradycardia
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What interventions might be done for bradycardia following cardiac surgery?
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Many postoperative patients will have temporary pacer wires that can be attached to a pulse generator (pacemaker) to stimulate the heart to beat faster. Less commonly, atropine, epinephrine, or isoproterenol may be used to increase heart rate.
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What is desribed as myocardial contractility may be decreased perioperatively?
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Cardiac failure
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What might be assessed in cardiac failure following cardiac surgery?
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The nurse observes for and reports falling mean arterial pressure; rising PAWP, pulmonary artery diastolic pressure, and CVP; increasing tachycardia; restlessness and agitation; peripheral cyanosis; venous distention; labored respirations; and edema.
Medical management includes diuretics, digoxin, and IV inotropic agents |
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What complication following cardiac surgery is described as a portion of the cardiac muscle dies; therefore, contractility decreases. Impaired ventricular wall motion further decreases cardiac output. Symptoms may be masked by the postoperative surgical discomfort or the anesthesia–analgesia regimen.
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MI
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What assessments/ interventions are done following cardiac surger if an MI is suspected?
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Careful assessment to determine the type of pain the patient is experiencing; MI suspected if the mean blood pressure is low with normal preload.
Serial ECGs and cardiac biomarkers assist in making the diagnosis (alterations may be due to the surgical intervention). Analgesics are prescribed in small amounts while the patient's blood pressure and respiratory rate are monitored (because vasodilation secondary to analgesics or decreasing pain may occur and compound the hypotension). Activity progression depends on the patient's activity tolerance. |
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What is the description of impaired gas exchange following cardiac surgery?
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During and after anesthesia, patients require mechanical assistance to breathe.
Potential for postoperative atelectasis. Anesthetic agents stimulate production of mucus and chest incision pain may decrease the effectiveness of ventilation. |
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What are some assessments/ interventions for impaired gas exchange following cardiac surgery?
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Pulmonary complications are often detected during assessment of breath sounds, oxygen saturation levels, arterial blood gases, and when monitoring peak pressure and exhaled tidal volumes on the ventilator.
Extended periods of mechanical ventilation may be required while complications are treated |
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What is untoward and excessive bleeding that mya be life threatening?
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hemorrhage
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What are some assessment/interventions for hemorrhage following cardiac surgery?
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Serial hemoglobin, hematocrit, and coagulation studies are performed to guide therapy.
Administration of fluids, colloids, and blood products: packed red blood cells, fresh frozen plasma, platelet concentrate. Administration of aprotinin (Trasylol) perioperatively to reduce blood transfusion needs. Administration of desmopressin acetate (DDAVP) to enhance platelet function. |
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What complication is suspected following cardiac surgery if the patient has an inability to follow simplc command w/in 6 hours of recovery fron anesthtic, different capacilites on the right or left side of body?
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neurologic changes/ Stroke
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What are some assessment/interventions for neurologic changes/stroke following cardiac surgery?
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Neurologically, most patients begin to recover from anesthesia in the operating room.
Patients who are elderly or who have renal or hepatic failure may take longer to recover. Patient should be evaluated for stroke when neurologic changes are evident |
