19
Coronary Artery Bypass Graft Coronary artery bypass surgery, also coronary artery bypass graft (CABG) surgery, and colloquially heart bypass or bypass surgery is a surgical procedure performed to relieve angina and reduce the risk of death from coronary artery disease. Arteries or veins from elsewhere in the patient's body are grafted to the coronary arteries to bypass atherosclerotic narrowings and improve the blood supply to the coronary circulation supplying the myocardium. This surgery is usually performed with the heart stopped, necessitating the usage of cardiopulmonary bypass or heart lung machine. Techniques are available to perform CABG on a beating heart, so-called "off-pump" surgery. History The first coronary artery bypass surgery was performed in the United States on May 2, 1960, at the Albert Einstein College of Medicine-Bronx Municipal Hospital Center by a team led by Dr. Robert Goetz and the thoracic surgeon, Dr. Michael Rohman with the assistance of Dr. Jordan Haller and Dr. Ronald Dee. In this technique the vessels are held together with circumferential ligatures over an inserted metal ring. The internal mammary artery was used as the donor vessel and was anastomosed to the right coronary artery. The actual anastomosis with the Rosenbach ring took fifteen seconds and did not require cardiopulmonary bypass. The disadvantage of using the internal mammary artery was that, at autopsy nine months later, the anastomosis was open, but an atheromatous plaque had occluded the origin of the internal mammary that was used for the bypass. Russian cardiac surgeon, Dr. Vasilii Kolesov, performed arguably the first successful internal mammary artery–coronary artery anastomosis in 1964. Dr. René Favaloro, an Argentine surgeon, achieved a physiologic approach in the surgical management of coronary artery disease—the bypass grafting procedure—at the Cleveland Clinic in May 1967. His new technique used a saphenous vein autograft to replace a stenotic segment of the right coronary artery. Later, he successfully used the saphenous vein as a bypassing channel, which has become the typical bypass graft technique we know today; in the U.S., this vessel is typically harvested endoscopically, using a technique known

cabg

Embed Size (px)

Citation preview

Page 1: cabg

Coronary Artery Bypass GraftCoronary artery bypass surgery, also coronary artery bypass graft (CABG) surgery, and colloquially heart bypass or bypass surgery is a surgical procedure performed to relieve angina and reduce the risk of death from coronary artery disease. Arteries or veins from elsewhere in the patient's body are grafted to the coronary arteries to bypass atherosclerotic narrowings and improve the blood supply to the coronary circulation supplying the myocardium. This surgery is usually performed with the heart stopped, necessitating the usage of cardiopulmonary bypass or heart lung machine. Techniques are available to perform CABG on a beating heart, so-called "off-pump" surgery.

History

The first coronary artery bypass surgery was performed in the United States on May 2, 1960, at the Albert Einstein College of Medicine-Bronx Municipal Hospital Center by a team led by Dr. Robert Goetz and the thoracic surgeon, Dr. Michael Rohman with the assistance of Dr. Jordan Haller and Dr. Ronald Dee. In this technique the vessels are held together with circumferential ligatures over an inserted metal ring. The internal mammary artery was used as the donor vessel and was anastomosed to the right coronary artery. The actual anastomosis with the Rosenbach ring took fifteen seconds and did not require cardiopulmonary bypass. The disadvantage of using the internal mammary artery was that, at autopsy nine months later, the anastomosis was open, but an atheromatous plaque had occluded the origin of the internal mammary that was used for the bypass.

Russian cardiac surgeon, Dr. Vasilii Kolesov, performed arguably the first successful internal mammary artery–coronary artery anastomosis in 1964.

Dr. René Favaloro, an Argentine surgeon, achieved a physiologic approach in the surgical management of coronary artery disease—the bypass grafting procedure—at the Cleveland Clinic in May 1967. His new technique used a saphenous vein autograft to replace a stenotic segment of the right coronary artery. Later, he successfully used the saphenous vein as a bypassing channel, which has become the typical bypass graft technique we know today; in the U.S., this vessel is typically harvested endoscopically, using a technique known as endoscopic vessel harvesting (EVH). In 1968, Doctors Charles Bailey, Teruo Hirose and George Green used the internal mammary artery instead of the saphenous vein for the grafting.

Terminology

Three coronary artery bypass grafts, a LIMA to LAD and two saphenous vein grafts – one to the right coronary artery (RCA) system and one to the obtuse marginal (OM) system. There are many variations on terminology, in which one or more of "artery", "bypass" or "graft" is left out. The most frequently used acronym for this type of surgery is CABG. More recently the term aorto-coronary bypass (ACB) has come into popular use.

Atherosclerosis is a common arterial disorder characterized by yellowish plaques of cholesterol, lipids, and cellular debris in the inner layer of the walls of large and medium-sized arteries.

Number of bypasses

The terms single bypass, double bypass, triple bypass, quadruple bypass and quintuple bypass refer to the number of coronary arteries bypassed in the procedure. In other words, a double bypass means two coronary arteries are bypassed (e.g. the left anterior descending (LAD) coronary artery and right coronary artery (RCA)); a triple bypass means three vessels

Page 2: cabg

are bypassed (e.g. LAD, RCA, left circumflex artery (LCX)); a quadruple bypass means four vessels are bypassed (e.g. LAD, RCA, LCX, first diagonal artery of the LAD) while quintuple means five. Bypass of more than four coronary arteries is uncommon.

A greater number of bypasses does not imply a person is "more sick", nor does a lesser number imply a person is "healthier." A person with a large amount of coronary artery disease (CAD) may receive fewer bypass grafts owing to the lack of suitable "target" vessels. A coronary artery may be unsuitable for bypass grafting if it is small (< 1 mm or < 1.5 mm depending on surgeon preference), heavily calcified (meaning the artery does not have a section free of CAD) or intra myocardial (the coronary artery is located within the heart muscle rather than on the surface of the heart). Similarly, a person with a single stenosis ("narrowing") of the left main coronary artery requires only two bypasses (to the LAD and the LCX). However, a left main lesion places a person at the highest risk for death from a cardiac cause

The surgeon reviews the coronary angiogram prior to surgery and identifies the lesions (or "blockages") in the coronary arteries. The surgeon will estimate the number of bypass grafts prior to surgery, but the final decision is made in the operating room upon examination of the heart.

Indications for CABG

1) Chronic angina

2) Unstable angina

3) Acute myocardial infarction

4) Acute failure of percutaneous transluminal coronary angioplasty (PTCA)

5) Severe coronary artery disease

Several alternative treatments for coronary artery disease exist. They include:

Medical management (anti-anginal medications plus statins, anti hypertensives, smoking cessation, tight blood sugar control in diabetics)

Percutaneous coronary intervention (PCI)

Both PCI and CABG are more effective than medical management at relieving symptoms (e.g. angina, dyspnea, fatigue). CABG is superior to PCI for some patients with multivessel CAD.

The Surgery or Stent (SoS) trial was a randomized controlled trial that compared CABG to PCI with bare-metal stents. The SoS trial demonstrated CABG is superior to PCI in multivessel coronary disease.

The 2004 ACC/AHA CABG guidelines state CABG is the preferred treatment for:

Disease of the left main coronary artery (LMCA). Disease of all three coronary vessels (LAD, LCX and RCA). Diffuse disease not amenable to treatment with a PCI.

The 2005 ACC/AHA guidelines further state: CABG is the preferred treatment with other high-risk patients such as those with severe ventricular dysfunction (i.e. low ejection fraction), or diabetes mellitus.

Prognosis

Prognosis following CABG depends on a variety of factors, and successful grafts typically last 8–15 years. In general, CABG improves the chances of survival of patients who are at

Page 3: cabg

high risk (generally triple or higher bypass); though statistically after about five years the difference in survival rate between those who have had surgery and those treated by drug therapy diminishes. Age at the time of CABG is critical to the prognosis, younger patients with no complicating diseases doing better, while older patients can usually be expected to suffer further blockage of the coronary arteries.

Controversy

The value of coronary artery bypass surgery in rescuing someone having a heart attack is clearly defined in multiple studies, but studies have failed to find benefit for bypass surgery vs. medical therapy in stable angina patients. The artery bypass can temporarily alleviate chest pain, but does not increase longevity. The "vast majority of heart attacks do not originate with obstructions that narrow arteries".

Loss of mental function is a common complication of bypass surgery, and should influence procedure cost benefit considerations. One published study using MRI imaging just after coronary bypass surgery found significant brain damage in 51% of patients.

Several factors may contribute to immediate cognitive decline. The heart-lung blood circulation system and the surgery itself release a variety of debris, including bits of blood cells, tubing, and plaques. For example, when surgeons clamp and connect the aorta to tubing, resulting emboli block blood flow and cause mini strokes. Other heart surgery factors related to mental damage may be events of hypoxia, high or low body temperature, abnormal blood pressure, irregular heart rhythms, and fever after surgery.

A safer and more permanent and successful way to prevent heart attacks in patients at high risk is to exercise, give up smoking, take "drugs to get blood pressure under control and drive cholesterol levels down to prevent blood clotting". Longer term, behavioral and medication treatment may be the only way to avoid vascular related loss of mental function.

Types of CABG

Conventional CABG

Beating heart CABG

Minimally invasive CABG:

1. Beating heart without CPB2. Port access with video

a. Assistance and closed chest b. CPB

Procedure (simplified)

1) The patient is brought to the operating room and moved on to the operating table.2) An anesthetist places a variety of intravenous lines and injects a sedative agent

(usually fentanyl) followed within minutes by an induction agent (usually propofol) to render the patient unconscious.

3) An endotracheal tube is inserted and secured by the anesthetist and mechanical ventilation is started. General anesthesia is maintained by a continuous very slow injection of Propofol.

4) The chest is opened via a median sternotomy and the heart is examined by the surgeon.5) The bypass grafts are harvested – frequent conduits are the internal thoracic

arteries, radial arteries and saphenous veins. When harvesting is done, the patient is given heparin to prevent the blood from clotting.

Page 4: cabg

6) In the case of "off-pump" surgery, the surgeon places devices to stabilize the heart.7) If the case is "on-pump", the surgeon sutures cannulae into the heart and instructs

the perfusionist to start cardiopulmonary bypass (CPB). Once CPB is established, the surgeon places the aortic cross-clamp across the aorta and instructs the perfusionist to deliver cardioplegia (a special potassium-mixture, cooled) to stop the heart and slow its metabolism. Usually the patient's machine-circulated blood is cooled to around 84 °F (29 °C)

8) One end of each graft is sewn on to the coronary arteries beyond the blockages and the other end is attached to the aorta.

9) The heart is restarted; or in "off-pump" surgery, the stabilizing devices are removed. In cases where the aorta is partially occluded by a C-shaped clamp, the heart is restarted and suturing of the grafts to the aorta is done in this partially occluded section of the aorta while the heart is beating.

10) Protamine is given to reverse the effects of heparin.11) Chest tubes are placed in the mediastinal and pleural space to drain blood from around the

heart and lungs.12) The sternum is wired together and the incisions are sutured closed.13) The patient is moved to the intensive care unit (ICU) to recover.14) Nurses in the ICU focus on recovering the patient by monitoring blood pressure, urine

output and respiratory status as the patient is monitored for bleeding through the chest tubes. If there are chest tube clogging, complications such as cardiac tamponade, pneumothorax or death can ensue. Thus nurses closely monitor the chest tubes and undertake methods to prevent clogging so bleeding can be monitored and complications can be prevented.

15) After awakening and stabilizing in the ICU (approximately one day), the person is transferred to the cardiac surgery ward until ready to go home (approximately four days).

Minimally invasive CABG

Alternate methods of minimally invasive coronary artery bypass surgery have been developed. Off-pump coronary artery bypass (OPCAB) is a technique of performing bypass surgery without the use of cardiopulmonary bypass (the heart-lung machine). 

Further refinements to OPCAB have resulted in minimally invasive direct coronary artery bypass surgery (MIDCAB), a technique of performing bypass surgery through a 5 to 10 cm incision.

Minimally Invasive Cardiac Surgery, also known as MICS CABG (Minimally Invasive Cardiac Surgery/Coronary Artery Bypass Grafting) or The McGinn Technique is heart surgery performed through several small incisions instead of the traditional open-heart surgery that requires a median sternotomy approach. MICS CABG is a beating-heart multi-vessel procedure performed under direct vision through an anterolateral mini-thoracotomy. Minimally Invasive Heart Surgery is favored by surgeons and patients because of reduced post-operative discomfort, faster healing times and lowered risk of infections or complications. This procedure makes heart surgery possible for patients who were previously considered to be too at risk for traditional surgery due to age or medical history. MICS CABG is performed through one window incision that stretches 5-7 cm in the 4th intercostal space (ICS). In some cases the thoracotomy may be necessary in the 5th ICS instead. A soft tissue refractor is used to allow for greater visibility and access.

Minimally Invasive Direct Coronary Artery Bypass (MIDCAB) is a surgical treatment for coronary heart disease that is a less invasive method of coronary (CABG). MIDCAB gains surgical access to the heart with a smaller incision than other types of CABG.

Page 5: cabg

MIDCAB is sometimes referred to as "keyhole" heart surgery because the operation is analogous to operating through a keyhole.

MIDCAB is a form of off-pump coronary artery bypass surgery (OPCAB), performed "off-pump" - without the use of cardiopulmonary bypass (the heart-lung machine). MIDCAB differs from OPCAB in the type of incision used for the surgery; with traditional CABG and OPCAB a median sternotomy (dividing the breastbone) provides access to the heart; with MIDCAB, the surgeon enters the chest cavity through a mini-thoracotomy (a 2-to-3 inch incision between the ribs).

MIDCAB surgery is no more reserved for anteriorly placed single- or double-vessel diseases, because recently such lesions are usually managed with angioplasty. Hence this surgery has recently been used in multivessel diseases.

Conduits used for bypass

The choice of conduits is highly dependent upon the particular surgeon and institution.

Typically, the left internal thoracic artery (LITA) (previously referred to as left internal mammary artery or LIMA) is grafted to the left anterior descending artery and a combination of other arteries and veins is used for other coronary arteries.

The right internal thoracic artery (RITA), the great saphenous vein from the leg and the radial artery from the forearm are frequently used; in the U.S., these vessels are usually harvested endoscopically, using a technique known as endoscopic vessel harvesting (EVH). The right from the stomach is infrequently used given the difficult mobilization from the abdomen.

Graft patency

Grafts can become diseased and may occlude in the months to years after bypass surgery is performed. Patency is the chance that a graft remains open. A graft is considered patent if there is flow through the graft without any significant (>70% diameter) stenosis in the graft.

Graft patency is dependent on a number of factors, including

the type of graft used (internal thoracic artery, radial artery, or great saphenous vein), the size or the coronary artery that the graft is anastomosed with, the skill of the surgeon(s) performing the procedure

Arterial grafts (e.g. LITA, radial) are far more sensitive to rough handling than the saphenous veins and may go into spasm if handled improperly.

Generally the best patency rates are achieved with the in-situ left internal thoracic artery (the proximal end is left connected to the subclavian artery) with the distal end being anastomosed with the coronary artery (typically the left anterior descending artery or a diagonal branch artery). Lesser patency rates can be expected with radial artery grafts and "free" internal thoracic artery grafts (where the proximal end of the thoracic artery is excised from its origin from the subclavian artery and re-anastomosed with the ascending aorta). Saphenous vein grafts have worse patency rates, but are more available, as the patients can have multiple segments of the saphenous vein used to bypass different arteries.

Veins that are used either have their valves removed or are turned around so that the valves in them do not occlude blood flow in the graft. LITA grafts are longer-lasting than vein grafts, both because the artery is more robust than a vein and because, being already connected to the arterial tree, the LITA need only be grafted at one end. The LITA is usually grafted to the left anterior descending coronary artery (LAD) because of its superior long-term patency when compared to saphenous vein grafts.

Page 6: cabg

Sternal precautions

Patients undergoing coronary artery bypass surgery will have to avoid certain things for eight to 12 weeks to reduce the risk of opening the incision. These are called sternal precautions.

First, patients need to avoid using their arms excessively, such as pushing themselves out of a chair or reaching back before sitting down. To avoid this, patients are encouraged to build up momentum by rocking several times in their chair before standing up.

Second, patients should avoid lifting anything in excess of 5–10 pounds.

Finally, patients should avoid overhead activities with their hands, such as reaching for sweaters from the top shelf of a closet or reaching for plates or cups from the cupboard.

Complications

People undergoing coronary artery bypass are at risk for the same complications as any surgery, plus some risks more common with or unique to CABG.

CABG associated

Post perfusion syndrome (pump head), a transient neurocognitive impairment associated with cardiopulmonary bypass. Some research shows the incidence is initially decreased by off-pump coronary artery bypass, but with no difference beyond three months after surgery. A neurocognitive decline over time has been demonstrated in people with coronary artery disease regardless of treatment (OPCAB, conventional CABG or medical management). However, a 2009 research study suggests that longer term (over 5 years) cognitive decline is not caused by CABG but is rather a consequence of vascular disease.

Nonunion of the sternum; internal thoracic artery harvesting devascularizes the sternum increasing risk.

Myocardial infarction due to embolism, hypoperfusion, or graft failure. Late graft stenosis, particularly of saphenous vein grafts due to atherosclerosis causing

recurrent angina or myocardial infarction. Acute renal failure due to embolism or hypoperfusion. Stroke, secondary to embolism or hypoperfusion. Vasoplegic syndrome, secondary to cardiopulmonary bypass and hypothermia Grafts last 8 – 15 years, and then need to be replaced. Pneumothorax: An air collection around the lung that compresses the lung Hemothorax: Blood in the space around the lungs Pericardial Tamponade: Blood collection around the heart that compresses the heart and

causes poor body and brain perfusion. Chest tubes are placed around the heart and lung to prevent this. If the chest tubes become clogged in the early post operative period when bleeding is ongoing this can lead to pericardial tamponade, pneumothorax or hemothorax.

Pleural Effusion: Fluid in the space around the lungs. This can lead to hypoxia which can slow recovery.

General cardiac surgery

Post-operative atrial fibrillation

General surgical

Infection at incision sites or sepsis

Deep vein thrombosis (DVT) Anesthetic complications such as malignant hyperthermia Keloid scarring Chronic pain at incision sites

Page 7: cabg

Chronic stress related illnesses DeathFollow up

Patients who have a coronary artery bypass surgery need regular monitoring from a physician. Among the changes in monitoring are five years after the surgery the addition of a regular cardiac stress test even when there is no change in the patient's status.

Nursing care of the client having a coronary artery bypass graft

PREOPERATIVE CARE

1) Provide routine preoperative care and teaching. 2) Verify presence of laboratory and diagnostic test results in the chart, including CBC,

coagulation profile, urinalysis, chest X-ray, and coronary angiogram. These baseline data are important for comparison of postoperative results and values.

3) Type and crossmatch four or more units of blood as ordered. Blood is made available for use during and after surgery as needed.

4) Provide specific client and family teaching related to procedure and postoperative care. Include the following topics-Cardiac recovery unit; sensory stimuli, personnel; noise and alarms; visiting policies, Tubes, drains and general appearance, Monitoring equipment, including cardiac and hemodynamic monitoring systems, Respiratory support: ventilator, endotracheal tube, suctioning; communication while intubated, Incisions and dressings

5) Pain management6) Preoperative teaching reduces anxiety and prepares the client and family for the

postoperative environment and expected sensations.

POSTOPERATIVE CARE

Provide routine postoperative care. In addition to the care needs of all clients having major surgery, the cardiac surgery client has specific care needs related to open-heart and thoracic surgery. These are outlined under the nursing diagnoses identified below-

a) Decreased Cardiac Output1) Cardiac output may be compromised postoperatively due to bleeding and fluid loss;

depression of myocardial function by drugs, hypothermia, and surgical manipulation; dysrhythmias; increased vascular resistance; and a potential complication, cardiac tamponade, compression of the heart due to collected blood or fluid in the pericardium.

2) Monitor vital signs, oxygen saturation, and hemodynamic parameters every 15 minutes.3) Note trends and report significant changes to the physician. Initial hypothermia and

bradycardia are expected; the heart rate should return to the normal range with rewarming. The blood pressure may fall during rewarming as vasodilation occurs. Hypotension and tachycardia, however, may indicate low cardiac output.

4) Pulmonary artery pressure (PAP), pulmonary artery wedge pressure (PAWP), cardiac output, and oxygen saturation are monitored to evaluate fluid volume, cardiac function, and gas exchange.

Page 8: cabg

5) Auscultate heart and breath sounds on admission and at least every 4 hours. A ventricular gallop, or S3, is an early sign of heart failure; an S4 may indicate decreased ventricular compliance. Muffled heart sounds may be an early indication of cardiac tamponade.

6) Adventitious breath sounds (wheezes, crackles, or rales) may be a manifestation of heart failure or respiratory compromise.

7) Assess skin color and temperature, peripheral pulses, and level of consciousness with vital signs. Pale, mottled, or cyanotic coloring, cool and clammy skin, and diminished pulse amplitude are indicators of decreased cardiac output.

8) Continuously monitor and document cardiac rhythm. Dysrhythmias are common and may interfere with cardiac filling and contractility, decreasing the cardiac output.

9) Measure intake and output hourly. Report urine output less than 30 mL/h for 2 consecutive hours. Intake and output measurements help evaluate fluid volume status. A fall in urine output may be an early indicator of decreased cardiac output.

10) Record chest tube output hourly. Chest tube drainage greater than 70 mL/hr or that is warm, red, and free flowing indicates hemorrhage and may necessitate a return to surgery. A sudden drop in chest tube output may indicate impending cardiac tamponade.

11) Monitor hemoglobin, hematocrit, and serum electrolytes. A drop in hemoglobin and hematocrit may indicate hemorrhage that is not otherwise obvious.

12) Electrolyte imbalances, potassium, calcium, and magnesium in particular, affect cardiac rhythm and contractility. Administer intravenous fluids, fluid boluses, and blood transfusions as ordered. Fluid and blood replacement helps ensure adequate blood volume and oxygen-carrying capacity. Administer medications as ordered. Medications ordered in the early postoperative period to maintain the cardiac output include inotropic drugs (e.g., dopamine, dobutamine) to increase the force of myocardial contractions; vasodilators (e.g., nitroprusside or nitroglycerin) to decrease vascular resistance and afterload; and antidysrhythmics to correct dysrhythmias that affect cardiac output. Keep a temporary pacemaker at the bedside; initiate pacing as indicated. Temporary pacing may be needed to maintain the cardiac output with bradydysrhythmias, such as high-level AV blocks.

13) Assess for signs of cardiac tamponade: increased heart rate, decreased BP, decreased urine output, increased central venous pressure, a sudden decrease in chest tube output, muffled/distant heart sounds, and diminished peripheral pulses. Notify physician immediately. Cardiac tamponade is a life threatening complication that may develop postoperatively. Cardiac tamponade interferes with ventricular filling and contraction, decreasing cardiac output. Untreated, cardiac tamponade leads to cardiogenic shock and possible cardiac arrest.

b) Hypothermia

Hypothermia is maintained during cardiac surgery to reduce the metabolic rate and protect vital organs from ischemic damage. Although rewarming is instituted on completion of the surgery, the client often remains hypothermic on admission to cardiac recovery. Gradual rewarming is necessary to prevent peripheral vasodilation and hypotension.

Page 9: cabg

Monitor core body temperature for the first 8 hours following surgery. Oral and rectal temperature measurements are not reliable indicators of core body temperature during this period. Institute rewarming measures (e.g., warmed intravenous solutions or blood transfusion, warm blankets, warm inspired gases, radiant heat lamps) as needed to maintain a temperature above 96.8 F (36° C). Administer Thorazine, morphine, or diltiazem as ordered to relieve shivering. Low body temperature may cause shivering, increasing oxygen demand and consumption. Hypothermia also increases the risk for hypoxia, metabolic acidosis, vasoconstriction and increased cardiac work, altered clotting and dysrhythmias.

c) Acute Pain

Following a CABG, pain is experienced due to both the thoracic incision and removal of the saphenous vein from the leg. Dissection of the internal mammary artery (usually the left IMA) from the chest wall also causes chest pain on the affected side. Chest tube sites are also uncomfortable. The leg from which the saphenous vein graft was obtained may be more painful than the chest incision.

1) Frequently assess for pain, including its location and character. Document its intensity using a standard pain scale.

2) Assess for verbal and nonverbal indicators of pain. Validate pain cues with the client. Pain is subjective, and differs among individuals.

3) Incisional pain is expected; however, anginal pain also may develop. It is important to differentiate the type of pain.

4) Decreased chest expansion or asymmetrical movement may indicate impaired ventilation of one lung, and needs further evaluation. Note endotracheal tube (ETT) placement on chest X-ray. Mark tube position and secure in place. Insert an oral airway if an oral ETT is used. Secure the tube firmly in place to prevent slippage or inadvertent removal. An oral airway helps prevent obstruction of an oral ETT by biting. Maintain ventilator settings as ordered.

5) Monitor arterial blood gases (ABGs) as ordered. Mechanical ventilation promotes optimal lung expansion and oxygenation postoperatively. ABGs are used to evaluate oxygenation and acid-base balance.

6) Suction as needed. Suctioning is performed only as indicated to clear airway secretions. Prepare for ventilator weaning and extubation, as appropriate. The client is removed from the ventilator and extubated as soon as possible to reduce complications associated with mechanical ventilation and intubation.

7) After extubation, teach use of the incentive spirometer, and encourage use every 2 hours. 8) Encourage deep breathing; advise against vigorous coughing. Teach use of a “cough

pillow” to splint chest incision and decrease pain. Deep breathing, controlled coughing, and position changes improve ventilation and airway clearance and help prevent complications. Vigorous coughing may excessively increase intrathoracic pressure and cause sternal instability.

9) Frequently turn and encourage movement. Dangle on postoperative day 1.

d) Risk for Infection

Page 10: cabg

Following an open chest procedure, a sternal infection may develop that can progress to involve the mediastinum. Clients with IMA grafts, who are diabetic, are older, or malnourished are at high risk. Harvesting of IMA disrupts blood supply to the sternum, and these clients have impaired immune responses and healing.

1) Assess sternal wound every shift. Document redness, warmth, swelling, and/or drainage from the site. Note wound approximation. These assessments provide indicators of inflammation and healing.

2) Maintain a sterile dressing for the first 48 hours, and then leave the incision open to air. Use Steri-Strips as needed to maintain approximation of the wound edges. The sterile dressing prevents early contamination of the wound, whereas leaving exposing the incision after 48 hours promotes healing.

3) Report signs of wound infection: a swollen, reddened area that is hot and painful to the touch; drainage from the wound; impaired healing, or healed areas that reopen. Evidence of infection or impaired healing requires further evaluation and treatment.

4) Culture wound drainage as indicated. Identifying the infective organism facilitates appropriate antibiotic therapy.

5) Collaborate with the dietitian to promote nutrition and fluid intake. Good nutritional status is vital to healing and immune function continued. Promptly report anginal or cardiac pain. Cardiac pain may indicate a perioperative or postoperative myocardial infarction.

6) Administer analgesics on a scheduled basis, by PCA, or by continuous infusion for the first 24 to 48 hours. Research demonstrates that adequate pain management in the immediate postoperative period reduces complications from sympathetic stimulation and allows faster recovery. Pain causes muscle tension and vasoconstriction, impairing circulation and tissue perfusion, slowing wound healing, and increasing cardiac work. Pre medicate 30 minutes before activities or planned procedures. Premedication and the subsequent reduction of pain improve client participation and cooperation with care.

e) Ineffective Airway Clearance/Impaired Gas Exchange

Atelectasis due to impaired ventilation and air way clearance is a common pulmonary complication of cardiac surgery. Gas exchange may also be affected by blood loss and decreased oxygen carrying capacity following surgery. Phrenic nerve paralysis is a potential complication of cardiac surgery which may also contribute to impaired ventilation and gas exchange.

1) Evaluate respiratory rate, depth, effort, symmetry of chest expansion, and breathe sounds frequently.

2) Pain, anxiety, excess fluid volume, surgical injury, narcotics and anesthesia, and altered homeostasis can affect respiratory rate, depth, and effort postoperatively.

f) Disturbed Thought Processes

Many factors affect neuropsychological function after CABG, including the length of cardiopulmonary bypass, age, presurgery organic brain dysfunction, severity of illness, and

Page 11: cabg

decreased cardiac output. Sensory overload and deprivation sleep disruption, and numerous drugs also affect thinking and mental clarity.

1) Frequently reorient during initial recovery period. State that surgery is over and that the client is in the recovery area. Frequent reorientation provides emotional support and reality checks.

2) Explain all procedures before performing them. 3) Speak in a clear, calm voice. Encourage questions, and give honest answers. These

measures provide information, decrease anxiety, and establish trust. 4) Secure all intravenous lines and invasive catheters/tubes (e.g., ETT, Foley catheter,

nasogastric tube). Disoriented clients may tug or pull at invasive equipment, disrupting them and increasing the risk of injury.

5) Note verbal responses to questions. Correct misconceptions immediately (e.g., “Mr. Snow, look at all the special equipment in this room. Does this room look like your bedroom at home?”).

6) Helping the client recognize differences in the hospital environment offers a basis for continual reality checks. Maintain a calendar and clock within the client’s view. This provides current information regarding day, date, and time.

7) Involve family members in providing reorientation. Place familiar objects and photographs within view. Encourage family presence. The family provides reassurance and contact with the familiar, assisting with orientation.

8) Promote client participation in care and decision making as appropriate. This allows the client to maintain a degree of power and control and enables the client to take an active role in recovery.

9) Report signs of hallucinations, delusions, depression, or agitation. These may indicate progressive deterioration of mental status.

10) Administer sedatives cautiously. Mild sedation may help prevent injury. Some sedatives may, however, have adverse effects, increasing confusion and disorientation.

11) Reevaluate neurologic status every shift. These data allow evaluation

Summary

Coronary artery bypass surgery, also coronary artery bypass graft (CABG) surgery, and colloquially heart bypass or bypass surgery is a surgical procedure performed to relieve angina and reduce the risk of death from coronary artery disease. Arteries or veins from elsewhere in the patient's body are grafted to the coronary arteries to bypass atherosclerotic narrowings and improve the blood supply to the coronary circulation supplying the myocardium. CABG is superior to PCI for some patients with multivessel CAD. People undergoing coronary artery bypass are at risk for the same complications as any surgery, plus some risks more common with or unique to CABG. The preoperative nursing management usually begins before hospitalization. Patients with nonacute heart disease may be admitted to hospital the day before or the day of their surgery. The intraoperative nursing management includes assisting in surgical procedure, continuous monitoring, monitoring for complications: dysrhythmias, hemorrhage, MI, CVA, embolization etc. the post operative management mainly includes monitoring the condition of patient, prevention of infection, nutritional status of the patient, health education etc.

Page 12: cabg

Bibliography

1) Sonya R. Hardin, Roberta Kaplow .Cardiac Surgery Essentials for Critical Care

Nursing. First edition. Jones & Bartlett Publishers, 2010,pg-115

2) "Bypass Surgery, Coronary Artery". American Heart Association. Retrieved March 26,

2010.

3) Ochsner JL, Mills NL (1978). Coronary artery surgery. Philadelphia: Lea & Febiger.

4) Susan L. Woods, Erika S. Sivarajan Froelicher. Cardiac nursing. 6th edition. Lippincott

Williams & Wilkins,2009,pg 432