Cardiovascular Study Guide for the CCRN

Cardiac Surgery

Several cardiac surgeries exist for varying vascular and heart conditions. Surgery is often required if the vascular flow to or through the heart is obstructed or limited in some way.

Coronary Artery Bypass Grafting (CABG)

Patients with severe cardiovascular occlusion can be candidates for a CABG procedure. This procedure is used in the event of severe coronary heart disease (CHD). It is indicated for cardiac vessel blockage where blood flow from the heart to the cardiac muscle is limited or obstructed. It is usually performed if the vessel blockage and CHD cannot be managed with other, less invasive measures, such as lifestyle changes, medications, angioplasty, or peripheral stenting.

The CABG procedure involves removing an arterial or vein graft from another part of the body and transplanting it to the cardiac vessel, bypassing the blocked or narrowed area. The most common vessels harvested include the left and right mammary arteries, saphenous vein, and radial artery. This procedure is one of the most common reasons for open-heart surgery.

Nursing Considerations

Patients who undergo a CABG will spend a few days in the intensive care unit following their procedure. Nurses must monitor those patients closely for complications of the procedure. Nurses should regularly assess the patient’s perfusion, heart rate, heart rhythm, blood pressure, and oxygen levels to ensure that the graft is working appropriately. Close monitoring of intake and output can help identify cardiac overload, renal changes (including decreased renal perfusion), and hemodynamic status. Be sure to teach patients the importance of splinting after open-heart surgery to provide support to the incision, reduce pain, and promote healing. An example of this is pressing a pillow firmly against their chest as they cough.

Infection

Assess the sternal suture site and chest tube insertion site for signs of infection, such as redness, purulent drainage, and dehiscence. Monitor temperature and labs such as ** white blood cells**. Patients should be encouraged to maintain good hygiene and wound care as ordered.

Bleeding

Bleeding may occur at the site of the graft removal or chest wound. Wound integrity should be monitored throughout the shift. Hemoglobin and hematocrit levels should be assessed regularly, generally every four hours, during the initial recovery period. Blood products may be ordered if bleeding is significant or the patient is hemodynamically unstable following the CABG procedure.

Atrial Fibrillation

Atrial fibrillation can occur following cardiac surgery. While it is not generally life threatening, it can cause issues with blood pooling and clotting. If atrial fibrillation persists, the patient may need to be further evaluated for medication therapy with antithrombotic medications or cardioversion.

Chest Tubes

Nurses will need to monitor the patient’s chest tube drainage. Drainage volumes over 100 mL/hour should be reported to the patient’s primary healthcare provider. Chest tube drainage should be serosanguineous in nature. Bright red drainage may be indicative of postoperative complications and bleeding and should be reported immediately.

Pain

Minimizing a patient’s pain level is important in the recovery process. Generally, patients will be prescribed morphine to help manage their pain. Many patients will be prescribed a patient-controlled analgesia pump (PCA).

Other Complications

As a critical care nurse, patients should also be monitored for a variety of other potential complications of CABG. These include:

systemic inflammatory response syndrome
heparin-induced thrombocytopenia
edema
graft failure or acute occlusion
postpericardiotomy syndrome
cardiac tamponade

Valve Replacement or Repair

Cardiac valve replacement or repair may be indicated if the valve is faulty or damaged. The most common diagnoses for this type of surgery include valve stenosis or regurgitation. Traditional valve replacement procedures require open-heart surgery. As technology has advanced over the years, newer procedures, such as the transcatheter aortic valve replacement, allow patients to undergo valve replacement in a less invasive manner.

There are two main categories of valve replacement options: mechanical and bioprosthetic. Mechanical valves are often made from carbon/titanium and are extremely durable, often lasting a lifetime. Bioprosthetic valves are xenografts and wear out more quickly, usually lasting one to two decades before needing replacement.

Following a valve replacement or repair, nurses must monitor patients closely for complications from the procedure. Common events that may occur include hypotension, pulsus paradoxus, cardiac tamponade, thrombus formation, and infection. Patients undergoing manipulation of the cardiac valves will also require lifelong anticoagulant therapy (especially for mechanical valves) and should be monitored closely for bleeding. Some patients will require placement of pacing devices.

Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement is a less invasive procedure used for patients at high risk for complications from open-heart surgery. This procedure treats severe aortic stenosis by placing a bioprosthetic valve over the existing aortic valve. This procedure has a shortened recovery time and generally fewer side effects than traditional surgical valve replacement.

Prior to undergoing a transcatheter aortic valve replacement, patients must have a transesophageal echocardiography (TEE) to determine the severity of their aortic stenosis. If a transcatheter aortic valve replacement is indicated, then the patient must be fitted for an appropriately sized bioprosthetic valve through a CT scan.

The incision sites for a transcatheter aortic valve replacement lie bilaterally in the groin, where the cardiac surgeon(s) can access the femoral vessels. A temporary right ventricular pacemaker and balloon aortic valvuloplasty are generally indicated to promote hemodynamic stability and reduce the workload of the heart.

Nurses should monitor patients closely for complications of this procedure. Patients may experience hypotension, aortic dissection or perforation, stroke, acute kidney injury, and bleeding. Patients will have strict bed rest orders for approximately six hours following the surgical procedure. Nurses should ensure that patients are placed on and understand the importance of anticoagulant therapy. Typically, a patient is put on dual antiplatelet therapy for the first 3 to 6 months, followed by lifelong aspirin therapy to prevent thrombosis and failure of the bioprosthetic valve.

Peripheral Stents

Peripheral stents are another therapy used to treat peripheral vascular insufficiency. Peripheral stents are placed in interventional radiology, usually by way of a balloon angioplasty. In balloon angioplasty, a catheter with a balloon tip is inserted into the blocked or narrowed vessel and then inflated to compress the blockage. After the blockage is compressed, a stent is placed to support the vessel and maintain patency of blood flow. This therapy can be used in both coronary and peripheral arteries.

Benefits

The most common patients to benefit from balloon angioplasty include those with iliac, renal, subclavian, or carotid artery stenosis. Restoring blood flow to the distal tissues reduces symptoms such as severe claudication and ischemic pain. It can also improve blood flow to non-healing ulcers and wounds.

Risks

Balloon angioplasty with peripheral stenting does not come without risk. Complications of this procedure include bleeding, infection, arterial spasm or rupture, dissection of the stented vessel, vessel stenosis, thrombus formation, and intravascular fracture of the stent. Nurses should monitor for bleeding at the insertion site, hematoma, infection, arrhythmias, and neurovascular changes (limb color, warmth, pulse strength, sensation, movement, pain, etc.). See the “Cardiac Catheterization” section for further nursing assessment and intervention requirements.

Cardiac Tamponade

Cardiac tamponade occurs when blood or fluid infiltrates the pericardial sac. It can occur in light of multiple conditions, including thoracic aortic aneurysm, end-stage lung or cardiac cancer, acute myocardial infarction, cardiac trauma, such as penetrating injuries, surgery, hypothyroidism, and pericarditis. Patients at highest risk for cardiac tamponade are those within the 24– to 72–hour postoperative window following cardiac surgery.

Symptoms

Nurses should monitor patients closely for signs and symptoms of cardiac tamponade. These can include acute anxiety; a sense of impending doom; sharp chest pain that can radiate to the neck, shoulder, back, or abdomen; difficulty breathing; decreased perfusion; hypotension; and lower extremity swelling. Nurses should be able to recognize the three classic symptoms known as Beck’s Triad: muffled heart sounds, low arterial blood pressure, and jugular vein distention. In addition to the hypotension, a narrow pulse pressure may be observed. This is a small difference between systolic and diastolic pressures (e.g., 80/70).

Assessment

A thorough assessment of the patient is essential to early recognition and preventing complications of cardiac tamponade, including death. Patients in acute distress will likely have an elevated heart rate over 100 bpm with muffled heart sounds. Neck veins may be distended despite hypotension. Pulses may be weak or absent, especially in the peripheral and lower extremities.

Diagnosis

The definitive test to confirm cardiac tamponade is an echocardiogram. Other tests, such as chest x-ray, ECG, and CT, can be useful in addition to this.

Treatment

The fluid around the heart must be drained as quickly and safely as possible. This is done by pericardiocentesis. This procedure is done by a physician under ultrasound guidance to place a catheter to drain the fluid. Death can occur if the fluid is not drained quickly. Nurses should place the patient on oxygen therapy, if not already on it, to help reduce the workload of the heart. IV fluids may be required to maintain the patient’s blood pressure and prevent hypotensive episodes as the blood/fluid is drained from the pericardial sac. Although a necessary and lifesaving procedure, it carries a risk of puncturing nearby structures, infection, and dysrhythmias. A chest x-ray is commonly performed afterward to rule out a pneumothorax. If pericardiocentesis is unsuccessful or in severe cardiac tamponade cases, the thoracic cavity may need to be opened by a surgeon to visualize the area. This is referred to as a thoracotomy.