12. Cardiac Surgery Flashcards
Cardiac Surgery
The exam questions r/t heart sx generally focus on complications and nursing care postop
Cardiopulmonary Bypass
-Aortic cross-clamping is done, and the heart is stopped during sx.
-Most common cannulation sites:
-Aorta
-Right atrium
-The longer the bypass time, the more bleeding there is and the more complications there may be postop
Coronary Artery Bypass Graft (CABG) Procedure
-Priming with isotonic crystalloids (hemodilution); enhances oxygenation by improving blood flow
-Hypothermia (28 - 36 C) is induced.
-Anticoagulation with large heparin doses.
-Rapid circulatory arrest is achieved during diastole with the infusion of a potassium cardioplegic agent; the cardioplegic agent is reinfused at regular intervals; note that either a warm or cold cardioplegic agent may be used.
Post-Op Assessment for Complications Related to CABG
-Hemodynamic abnormalities
-Arrhythmias
-Tamponade
-Pericarditis
-Electrolyte abnormalities
-hematologic abnormalities, bleeding
-Pulmonary problems (pneumonia, atelectasis, difficulty weaning from mechanical ventilation)
-Pain, anxiety
-renal failure
-endocrine problems (issues with glycemic control)
-GI problems (nausea, vomiting, ileus)
-infections
**Post-Op Chest Tube Management (cabg)
-Maintain patency.
-Do not allow dependent loops
-Milking or stripping chest tubes is not routinely
indicated.
-If clots appear, gently milk the chest tubes
-Mediastinal chest tubes remove serosanginous fluid from the operative site, whereas pleural chest tubes remove air, blood, or serous fluid from the pleural space.
-Keep chest tubes lower than pt’s chest.
-Do not clamp the system unless you are changing the drainage system or there is a system disconnect. When the tube is clamped, the connection to the negative chamber is lost.
-A chest tube output > 100 mL for 2 consecutive hours generally requires intervention.
-Maintain hemodynamic stability
-Correct the volume status
-Administer blood products.
Valve Surgery: Mechanical Valve Adv & Disadv.
Advantages of mechanical valve:
-Relatively easy to insert
-Very reliable
-Lasts longer than biological valve
Disadvantages of mechanical valve:
-high risk of thrombosis
-permanent anticoagulant therapy
Valve Surgery: Biological Valve Adv & Disadv.
Advantages of biological valve
- Only short-term anticoagulation is required (but the pt will need long-term anti platelet [ASA] therapy)
Disadvantages:
-Wears down, especially in high-pressure systems
Nursing Considerations Post-Valve Repair or Replacement
-Avoid a drop in preload. Most pts who have had valvular stenosis or chronic regurgitation have had elevated end-diastolic volumes. Sudden preload normalization may result in hypotension.
-Anticoagulation will be needed for mechanical valve replacement; biological valve replacement will require antiplatelet therapy (aspirin).
-Anticipate CONDUCTION DISTURBANCES since the mitral, tricuspid, and aortic valves are anatomically close to conduction pathways. Temporary or permanent pacing may be needed.
Transcatheter Aortic Valve Replacement (TAVR)
-TAVR, which was approved in 2011, is a procedure that involves placement of a collapsible prosthetic valve (either bovine or porcine) over the diseased valve (either a native valve or a previously placed artificial valve).
-Access to the aorta is usually achieved percutaneously or through a small incision, avoiding cross-clamping of the aorta and cardiopulmonary bypass.
-Most TAVR procedures are done via the femoral artery and are performed in a cardiac Cath lab that is modified to accommodate TAVR procedures
Ideal candidates for TAVR are those with
severe aortic valve disease that is classified as HIGH-RISK for open surgery
-Those who are at an intermediate risk for open surgery may qualify for either TAVR or open surgical replacement, depending upon a decision from the interdisciplinary heart valve team based on an evaluation of the pt.
-Pts who are considered extreme high-risk/inoperable or low-risk for open procedure are NOT candidates for TAVR
-NOTE: there are studies looking at TAVR for a pt who is classified as LOW-RISK for an open procedure for aortic valve replacement, but as of now, a low-risk pt is not considered an ideal candidate for this procedure
Complications of TAVR
Vascular complications associated with femoral access (similar to post-PCI, including hematomas, retroperitoneal bleeding, and arterial occlusion); heart block; stroke; acute kidney injury; and paravalvular regurgitation (associated with a mismatch of the prosthetic valve and the native valve annulus)
Post TAVR, what meds will be required post-procedue?
Dual antiplatelet therapy will be required, including aspirin (75 - 100 mg/day) for life and clopidogrel (75 mg/day) for 3 - 6 months post procedure.
