Nursing Care of the Patient Undergoing Coronary Artery Bypass Grafting

Journal of Cardiovascular Nursing Vol. 21, No. 2, pp 109Y117 x B 2006 Lippincott Williams & Wilkins, Inc.

Caron G. Martin, MSN, RN; Sandra L. Turkelson, MSN, RN

The role of the professional nurse in the perioperative care of the patient undergoing open heart surgery is beneficial for obtaining a positive outcome for the patient. This article focuses on the preoperative and postoperative nursing care of patients undergoing coronary artery bypass graft surgery. Risk assessment, preoperative preparation, current operative techniques, application of the nursing process immediately after surgery, and common postoperative complications will be explored. KEY WORDS: cardiac bypass, outcomes, perioperative nursing

oronary artery bypass graft (CABG) surgery is The Preoperative Phase Cindicated for patients with coronary artery disease to relieve symptoms, improve quality of life, Preoperative preparation of patients and significant and/or prolong life. More than 300,000 patients others is a well-established protocol in most institu- undergo CABG surgery annually in the United States tions. Research has shown that education of the with an initial hospital cost of approximately patient prior to surgery assists with recovery, increases $30,000 per patient. As operative techniques con- patient contentment, and decreases postoperative 2 tinue to improve and perioperative care is enhanced, complications. Appropriate timing of preoperative patients who were once denied surgery may now be preparation is helpful for the patient’s information surgical candidates. With this increase in the com- retention. Because impending open heart surgery is plexity of surgical cases, it becomes even more cru- anxiety provoking to most patients, it is imperative cial that there be an effective collaboration among for the nurse to assess the patient for individual the surgeon, the anesthesiologist, the perfusionist, learning needs and provide the information in a and the perioperative nursing staff.1 timely manner to minimize as much anxiety as pos- The patient undergoing CABG surgery deserves to sible. It has been suggested that state anxiety levels have confidence that the professional nurse is knowl- are lower 5 to 14 days prior to CABG surgery, which 3 edgeable, caring, efficient, and effective in providing makes this an ideal time for teaching. A high anxi- necessary perioperative care. Proper preparation of ety level is not conducive to retention of informa- the patient and significant others, expertise during tion. Benefits of preoperative teaching may be the intraoperative phase, and a thorough knowledge maximized when information is presented during base combined with skill and compassion of the the period when the patient has the lowest anxiety. nursing staff during the postoperative phase increase Many patients are admitted on the day of surgery. the likelihood of a positive outcome for the patient. Bringing them into the hospital for preadmission testing several days before surgery and completing the preoperative teaching during this time may be Caron G. Martin, MSN, RN effective. Some patients want specific details about Associate Professor, School of Nursing and Health Professions, the perioperative experience, whereas others seem to Northern Kentucky University, Highland Heights, Ky. need only the reassurance that a knowledgeable and Sandra L. Turkelson, MSN, RN Assistant Professor, School of Nursing and Health Professions, compassionate caregiver will provide the needed Northern Kentucky University, Highland Heights, Ky. perioperative care. The skilled professional nurse Special thanks to Dr Karl Ulicny (Cardiac Surgeon), Dr Richard Oliver individualizes preoperative instruction to meet the (Anesthesiologist), and John Baugh (Perfusionist) for sharing their specific needs of that patient. expertise. Information when conducting preoperative teach- Corresponding author Caron G. Martin, MSN, RN, School of Nursing and Health Professions, ing with a patient scheduled for CABG surgery may Northern Kentucky University, 332 Albright Health Center, Nunn include sights and sounds that will be experienced, Drive, Highland Heights, KY (e-mail: [email protected]). invasive lines that will be inserted, anticipated

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Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. 110 Journal of Cardiovascular Nursing x March/April 2006 sensations from preoperative medications, and antici- TABLE 1 Important Preoperative Teaching pated length of the operation. During the preopera- Points tive teaching session, the nurse should also provide Focus Points for Preoperative Patient Education information related to postoperative expectations. Reassurance that pain will be managed during the 1. Sights and sounds in the perioperative environment postoperative period is important to communicate to 2. Insertion of monitoring lines 3. Preoperative medications and anticipated sensations the patient and significant other. Teaching about 4. Use of incentive spirometer incision splinting and availability of effective pain 5. Length of the operation medications should be emphasized. 6. Expectations related to postoperative environment Patients should be informed that an endotracheal 7. Availability of postoperative pain medication and tube will probably be in place postoperatively, re- nursing staff 8. Effectiveness of splinting incision for pain control sulting in a temporary inability to speak. Assure the 9. Postoperative presence of an endotracheal tube patient that a competent caregiver will be in close 10. Anticipated time of intubation proximity during the immediate postoperative recov- 11. Communication issues ery period and will be able to anticipate and provide 12. Postoperative activity for needs. The patient should be assured that the 13. Preparation of the significant other endotracheal tube will be removed as soon as it is no longer needed. peripheral intravenous catheter, an arterial line, and Pulmonary care is an important part of the a pulmonary artery catheter. These are needed so postoperative care of the patient after CABG sur- intravenous fluids can be administered and hemody- gery. Preoperative practice with the equipment (such namics monitored during the operation and in the as an incentive spirometer) that will be used post- postoperative period. operatively is helpful. Teaching in the preoperative After the insertion of the invasive lines, anesthesia period assists the patient to comprehend the ne- will be administered. It is important to provide anes- cessity of coughing effectively in spite of incisional thesia, analgesia, and amnesia with agents utilized pain to achieve positive outcomes postoperatively. during the operation. These effects may be accom- Early mobilization is effective in improving post- plishedwithinhalationandintravenousagents. operative pulmonary outcomes.4 Preoperative teach- After anesthesia is induced the patient will be given ing might include information related to the a neuromuscular blocking agent, such as pancuro- potential for mobilization to a chair during the first nium or rocuronium, to facilitate endotracheal intu- evening postoperatively. bation and relax the skeletal muscles. Inhalation The significant other may be anxious and this agents and intravenous narcotics are given to induce may intensify as his/her loved one is taken to surgery. anesthesia. Examples of inhalation agents are des- Separation is inevitable, but communication with the flurane and sevoflurane. Inhalation agents can be significant other during the intraoperative period is cardiodepressive, so providing the minimum dose helpful to minimize anxiety. There are often ques- for the therapeutic effect is desired. Narcotic agents tions about the length of the operation, the condition such as fentanyl will assist with anesthesia and will of the patient, and when the anticipated reunion will also promote analgesia.5 Amnesia can be accom- be possible. plished with the inhalation agents as well as with Nursing interventions important for significant a benzodiazepine such as midazolam. After the others include teaching them about the expected patient is anesthetized, there will be a head-to- patient appearance. The patient may appear pale, toe surgical preparation and insertion of a urinary cool, and edematous. The nurse should also discuss catheter. equipment that will be connected to the patient. This The standard surgical approach is via a median equipment will include the ventilator, chest tubes, sternotomy. Sources of grafts can be the internal nasogastric tube, invasive lines, and urinary catheter mammary artery, the radial artery, the gastroepiploic (see Table 1). artery, and/or the saphenous vein. The internal mammary and the saphenous vein continue to be The Intraoperative Phase most commonly used for grafts. At 5 years postoperatively, 70% to 80% of saphenous vein grafts The intraoperative events during cardiac surgery are patent compared with a 40% to 60% patency influence nursing care postoperatively. A typical sce- rate at 10 years. In comparison, there is a 90% nario will be discussed to assist the nurse in under- patency rate of internal mammary artery grafts at 10 standing rationale for postoperative care. years.1 Heparin is administered to promote anti- Prior to initiation of anesthesia, most cardiac sur- coagulation. The activated clotting time is measured gery patients undergo the insertion of a large-bore during surgery to determine the effectiveness of the

Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. Care of the Coronary Artery Bypass Graft Patient 111 anticoagulation and therefore guide the amount of With the OPCAB procedure, a $-adrenergic block- heparin that is administered. ing medication such as esmolol may be used to slow The cardiopulmonary bypass (CPB) machine can the heart for the anastomoses to be completed. be used during the operation to maintain cardio- Surgical stabilizers may be used to decrease the pulmonary function and tissue perfusion. Sites of motion of the heart so that the surgeon can complete cannulation for CPB are usually the aorta and the the anastomoses.8 Heparin is administered with the right atrium. After the aorta is cross-clamped, car- OPCAB to prevent potential clotting. The patient dioplegia is administered to stop the heart. Cardio- may receive protamine to reverse the heparin at the plegia can be a cold solution that is high in potassium. end of the operation. A smaller dose of heparin may In certain patient populations, warm blood cardio- be used with the OPCAB than if extracorporeal plegia may be indicated.1 The surgeon performs the circulation is used. Fluid shifts and hematuria re- anastomoses while the heart is stopped. The shorter lated to long pump times would be minimized and the time on the bypass machine, the less likely there hemodilution from priming the CPB machine is not will be complications related to extracorporeal an issue with the OPCAB. Also, there may be fewer circulation. The inflammatory response is activated complications from the inflammatory response that secondary to cardiac surgery. This may be related to appears to be related to blood contact with the the manipulation of the heart and/or the effects of bypass machine.9 The patient’s postoperative body the CPB machine.6 temperature may be lower than a patient who was During extracorporeal circulation, anesthesia may on bypass because the heat exchanger on the pump be maintained with propofol, an intravenous medi- cannot be utilized for warming. Because of the cation that provides anesthesia as well as amnesia. reduced body temperature, bleeding may be exacer- Propofol can cause myocardial depression and hypo- bated. Because there is no need for cannulation of tension so the hemodynamic status of the patient the aorta and the right atrium, there are fewer should be closely monitored. Propofol is contra- puncture sites for potential postoperative bleeding. indicated in patients with allergies to soybean oil or eggs.7 Rewarming the body must occur prior to the The Postoperative Phase completion of the operation to begin to offset the Postoperative care of the cardiac surgery patient is surgically induced hypothermia. Rewarming is ini- challenging in that changes can occur rapidly. The tiated with the heat exchanger on the bypass machine preoperative condition of the patient as well as intra- while the surgeon finishes the anastomoses. The cross operative events should be considered in postopera- clamp is then removed from the aorta. The intrinsic tive care. It is essential for the nurse to anticipate the cardiac rhythm is often spontaneously reestablished possible complications so that appropriate interven- as blood begins to flow through the heart. Some- tions are initiated in a timely manner in order to times defibrillation is necessary if the heart does ensure a positive outcome for the patient. not automatically resume sinus rhythm. After the There is a flurry of activity as the patient enters adequacy of the heart rate and blood pressure (BP) the recovery room/ICU and the admitting nurse is certain, the patient is separated from the CPB connects the patient and the invasive lines to the machine and protamine sulfate is administered to monitoring equipment while another staff member reverse the effects of the heparin. Inotropic agents connects drainage devices appropriately and draws may be required to wean the patient from the bypass admission blood work. The operating room nurse machine if cardiac index is diminished. Epicardial and the anesthesiologist report the patient’s condi- atrial and ventricular pacemaker wires may be tion to the receiving nurse. inserted at this time. Mediastinal and/or pleural chest tubes will be inserted. The sternum is wired, the Postoperative Pulmonary Management tissues are sutured, surgical dressings are placed, and the patient is transported to the recovery room. Pulmonary dysfunction and hypoxemia may occur in Some surgeons elect off-pump coronary artery 30% to 60% of patients after CABG.10 Patient his- bypass (OPCAB). The potential complications of tory and intraoperative factors must be considered in extracorporeal circulation are minimized with this the postoperative pulmonary management. A history surgical option.8 Research has been conducted re- of smoking, obstructive pulmonary disease, steroid lated to the benefit of the OPCAB procedure. use, gastroesophageal reflux disease, heart failure, Potential benefits include a decreased need for blood and poor nutrition may increase postoperative pul- transfusions, decreased time in the intensive care monary complications.11 unit, and reduced hospital time with a potential de- Although there are some variations to this proto- crease in hospital cost.1 col, most patients will be intubated and mechanically

Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. 112 Journal of Cardiovascular Nursing x March/April 2006 ventilated upon arrival in the recovery room. Desired of hemothorax or pneumothorax, and size of the outcomes include adequate oxygenation and ventila- heart. tion while the patient is intubated. Early extubation Pain control is usually achieved with intravenous is also a desired outcome as long as the patient is narcotics while the patient is intubated. Oral and/or hemodynamically and neurologically stable. There is intravenous narcotics may be used after extubation. potential for an increase in postoperative complica- The nurse must balance the need for pain control tions when patients are intubated longer than 24 without respiratory depression with the patient’s need hours. The length of hospital stay may also increase to have his/her pain minimized to allow an effective with longer intubation times.12 The current trend is cough. to extubate patients within the first 12 hours after The nurse must assess the patient for readiness for surgery. On occasion, patients may be extubated in early extubation. Extubation should be considered the operating room. Routine postoperative care to when the patient is arousable, able to follow com- promote oxygenation and ventilation involves pre- mands, hemodynamically stable, and initiating spon- vention and treatment of atelectasis and pulmonary taneous ventilations without excessive respiratory infection as well as maintenance of effective gas effort. Typical intensive care protocols for the cardiac exchange and breathing patterns. surgery patient include preprinted orders that facili- There are several factors during heart surgery that tate the weaning process. As the patient is being increase the potential for pulmonary complications weaned from the ventilator, ventilatory support is postoperatively. The length of the surgery and resul- gradually withdrawn and the patient must sustain tant increase in the amount of needed anesthetic spontaneous ventilations. Physical assessment of agents, the amount of fluids administered during the effective ventilation, and laboratory analysis of arte- intraoperative period, and prolonged time in the rial blood gases and specific ventilatory parameters supine position increase the potential for pulmonary must be completed prior to extubation. Protocols may complications. Atelectasis can be related to cardio- vary, but some standards require a PO2 9 80 mm Hg pulmonary bypass, surfactant inhibition, and stimu- on a FIO2 of 0.40 or less, a PCO2 less than 45 mm Hg, lation of the inflammatory response.9 Atelectasis, as a pH between 7.35 and 7.45, and an oxygen satu- well as the inflammatory mediators, inhibits diffu- ration (SaO2) 992%. Ventilatory parameters include sion of oxygen and carbon dioxide across the a maximum inspiratory pressure of at least j20, a alveolar capillary membrane and impairs effective tidal volume of at least 5 mL/kg body weight, and gas exchange. Prolonged pump time causes fluid a minute volume of at least 5 liters per minute (see shifts, potentially increasing the amount of fluid in Table 2). During the weaning process, the nurse the pulmonary tissue, thus increasing the possibility should assess the patient for an increase in respira- of pulmonary complications. Pain caused from the tory and/or heart rates, use of accessory muscles, sternotomy can impair breathing patterns. Some fatigue, and color changes because these findings patients shiver after heart surgery and this response may indicate the patient is not ready for extubation. may lead to an increase in the carbon dioxide level An increase in pulmonary artery pressures can indi- or lead to lactic acidosis. Shivering may increase the cate an increase in PCO2 and give the nurse an early body’s oxygen consumption, therefore, oxygen levels indication prior to arterial blood gas analysis that should be monitored and adjusted accordingly. the patient is not ready for extubation. Early extu- Shivering may be the result of the body compensat- bation is desirable but if parameters are not met and/ ing for the surgically induced hypothermia or a reaction to anesthetic agents. Shivering is usually managed by administration of sedation and neuro- TABLE 2 Extubation Weaning Parameters muscular blocking agents while the patient is being Parameters Extubation Criteria mechanically ventilated. PO greater than 80 mm Hg Postoperative management includes accurate and 2 FIO2 0.40 or less frequent physical assessment, arterial blood gas PCO2 less than 45 mm Hg analysis, continuous pulse oximetry, pulmonary care pH 7.35Y7.45 (including suctioning while the patient is intubated SaO2 greater than 92% and coughing and incentive spirometry after extu- Maximum inspiratory less than j20 pressure bation), early mobilization, and control of pain and Tidal volume greater than 5 mL/kg body shivering. Most protocols require a chest x-ray after weight heart surgery to determine placement of the endo- Minute volume greater than 5 L/min tracheal tube, thermodilution catheter, and naso- FIo indicates fraction of inspired oxygen; Pco , partial pressure of arterial gastric tube as well as information about the width 2 2 carbon dioxide; Po2, partial pressure of arterial oxygen; Sao2,oxygen of the mediastinum, amount of atelectasis, presence saturation; mm Hg, millimeters of mercury.

Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. Care of the Coronary Artery Bypass Graft Patient 113 or the patient is hemodynamically unstable, there TABLE 3 Potential Treatment for Hemodynamic may be detrimental effects of early extubation. Changes After CABG Parameters Treatment Postoperative Management of SVR CI BP PCWP Hemodynamics ,, j Inotrope Movement of the patient from the operating room ,, , Volume j,j to the recovery room/ICU can create hemodynamic Vasodilator ,j, Vasoconstrictor instability, and thus, reconnection to the monitoring equipment in a timely manner is of the essence. A BP indicates blood pressure; CI, cardiac index; PCWP, pulmonary cuff BP is usually taken to provide correlation of the capillary wedge pressure; SVR, systemic vascular resistance; ,, decreased; j, increased. BP obtained from the arterial line. Intraoperative myocardial ischemia is a potential cause of low cardiac output (CO) during the imme- and by position changes. The patient should be put diate postoperative period. The nurse must continu- in the supine position with legs elevated to allow the ally assess the patient for cardiac dysfunction and BP to increase until the cause of the low BP can hemodynamic instability. The receiving nurse must be determined and corrective measures are taken. intensively monitor the interrelationship between Although not universally utilized, some institutions heart rhythm and rate, preload, afterload, contrac- continue to place patients in the Trendelenburg tility, and myocardial compliance to achieve this position. The Trendelenburg position can offer outcome. Preload is determined by the volume of symptomatic relief from low BP, especially in the blood returning to the right atrium as well as by early postoperative phase, by shifting volume from myocardial compliance. Preload is a measurement of the legs to the chest and increasing preload. The end diastolic pressure. Afterload is the force the positive changes identified with Trendelenburg posi- left ventricle must overcome to eject blood during tioning seemed to provide only temporary improve- systole. It is determined, in part, by myocardial ment in the clinical picture.15 contractility and systemic vascular resistance. Myo- If the BP becomes too high, especially in the early cardial contractility refers to the force generated by postoperative period, the surgical anastomoses may the heart during systole.13 Myocardial compliance is become disrupted, which could cause significant the ease with which the heart distends during intrathoracic bleeding, hemodynamic instability, diastole.14 poor tissue perfusion, and necessitate a return to Blood pressure must be maintained within or- the operating room. It is important for the nurse to dered parameters to provide tissue perfusion and carefully monitor the patient for high BP and quickly prevent disruption of the surgical anastomoses. BP is intervene per institution protocol. Nitroprusside, a CO multiplied by systemic vascular resistance (SVR). vasodilator, is often administered to lower the BP to The nurse must monitor the volume in the system, the ordered parameter. Nitroglycerine, a nitrate, may which is reflected by the right atrial pressure (RAP) also be used to cause vasodilation and lower the BP and pulmonary capillary wedge pressure (PCWP). (see Table 3). These medications should be started If the BP is too low, there is either too little volume slowly so patient response can be evaluated. The (preload), a decrease in contractility, or the SVR is patient must be monitored closely as the BP may too low (the patient’s blood vessels are dilated). If the drop as the patient’s body temperature increases. BP, CO, and RAP/PCWP are all low, the patient The nurse must rewarm the patient after surgery probably needs volume (see Table 3). Volume is if hypothermia persists. The negative effects of generally replaced as needed with a colloid such as hypothermia include depression of the myocardium, hetastarch unless the hematocrit is low and then ventricular dysrhythmias, vasoconstriction, and de- volume may be replaced with packed red blood cells. pression of clotting factors (increasing the risk of If the BP and CO are low but the PCWP is high, the bleeding postoperatively).13 Many surgeons attempt patient may be experiencing decreased contractility to achieve normothermia because of the deleterious and inotropic support may be instituted with an effects of hypothermia. If the patient is hypother- agent such as dopamine or dobutamine. If the BP is mic, rewarming may be accomplished by the use low and the CO is adequate or elevated, the systemic of warm blankets, warm humidified oxygen, con- vascular resistance may be low and the patient may vective air mattresses, and other individual institu- need a constrictive agent such as phenylephrine (see tional approaches.13 Vasoconstriction induced by Table 3). Low BP can be temporarily increased by hypothermia may increase BP. Because of the poten- turning off positive end expiratory pressure (to de- tial for issues with graft anastomoses and the im- crease intrathoracic pressure and augment preload) portance of maintaining BP within the reference

Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. 114 Journal of Cardiovascular Nursing x March/April 2006 range, a vasodilator may be needed while the patient cardial ischemia may be factors in postoperative is rewarming. As normothermia is achieved, if the dysrhythmias. Dysrhythmias can also be the result patient’s systemic vascular resistance decreases sig- of an increase in catecholamine levels secondary to nificantly, additional intravenous fluids may need to pain, anxiety, and inadequate sedation.17 Manage- be administered. ment depends on the type of dysrhythmia and the The nurse should carefully monitor the pulmo- patient’s clinical response. The nurse must treat the nary artery pressures and the CO as well as the BP patient and not only the monitor. Effectiveness of BP when interventions are instituted to assess the effect. and CO should be considered when evaluating Some references suggest that hemodynamic parame- dysrhythmias. Often, cardiac surgeons place epicar- ters be rechecked every 30 to 60 minutes after each dial wires on the atrium and/or the ventricle during intervention during the early postoperative period.14 the operation. Temporary pacing can be instituted to It is important to maintain effective CO after open override a slow intrinsic rhythm so CI and BP can be heart surgery to provide adequate tissue perfusion. maintained. Atropine may be given to increase the Cardiac index can be decreased if the heart rate heart rate in the absence of epicardial pacing wires. increases to the point of compromised ventricular Tachydysrhythmias are usually controlled pharma- filling with a resultant decrease in the stroke volume. cologically. The specific medication utilized will Cardiac index (CI) can also be decreased with depend on hospital protocols and physician prefer- bradycardia. Cardiac index can be decreased if the ence. The critical care nurse should utilize standing SVR (afterload) is elevated, making it more difficult orders in the institution as well as current advanced for the ventricles to eject the end diastolic volume of cardiac life support protocols. blood. One factor that can cause an elevation in afterload is the surgically induced hypothermia lead- Postoperative Management of Bleeding ing to vasoconstriction. A decrease in myocardial contractility or circulating volume can further com- The postoperative period may be complicated by promise CI. If the patient is hypothermic, this may excessive bleeding. Many factors should be consid- result in myocardial depression, thus compromis- ered when assessing the patient’s potential for bleeding contractility.13 After the cause of the decrease in ing. Patients who were on anticoagulants and the CO/CI is determined, management can be antiplatelet agents (including glycoprotein IIb/IIIa initiated. If the CO/CI is low and the PCWP is high, receptor antagonists such as abciximab) prior to inotropic support is probably needed. If the CO/CI surgery are at an increased risk of postoperative is low and the PCWP is low, volume is likely needed bleeding.19 The aorta and the atrium are cannulated (see Table 3). If the SVR is elevated in the early during surgery. The grafts have proximal and distal postoperative period, it may be due to hypothermia anastomosis sites. Other potential sites for bleeding or the patient may need volume. include the internal mammary site, the chest wall, It is easy to rely only on the values obtained with and chest tube sites. Induced hypothermia, the use of hemodynamic monitoring when assessing a patient. the CPB machine, and the administration of heparin The nurse must also use effective clinical assessment for anticoagulation can all contribute to postopera- skills. Peripheral perfusion assessment data are vi- tive bleeding. The nurse should be aware that tally important in the evaluation of effective CO.16 heparin can be stored in adipose tissue and some The nurse should regularly perform neurovascular patients may have an increase in bleeding 4 hours assessments of the lower extremities to provide in- postoperatively depending on the body’s adipose formation about the effectiveness of CO.14 composition. Some surgeons utilize an intravenous Dysrhythmias are common after CABG surgery. infusion of aprotinin intraoperatively to minimize Constant assessment of the patient, as well as con- the risk of postoperative bleeding. This drug is a tinuously monitoring the cardiac rate and rhythm, is protease inhibitor that inhibits fibrinolysis.20 Apro- imperative. Ventricular dysrhythmias are more com- tinin may also have some anti-inflammatory effects mon in the early postoperative period and supra- and therefore be beneficial to the patient after ventricular dysrhythmias are more likely 24 hours to CABG.21 5 days postoperatively.17 The incidence of atrial The nurse should monitor the patient for signs of fibrillation ranges from 10% to 65% depending on bleeding from the chest tubes and the surgical sites as many factors including patient history, preoperative well as clinical signs of hypovolemia related to blood medications, and type of surgery.18 Hypothermia, loss. Hemoglobin and hematocrit should be moni- inhaled anesthetics, electrolyte disturbances (ie, tored at regular intervals during the postoperative hypocalcemia, hypercalcemia, hypomagnesium, and period according to institution protocol. Sometimes hypokalemia), metabolic disturbances (such as aci- the surgeon orders serial coagulation profiles for a dosis), manual manipulation of the heart, and myo- patient at risk for bleeding. If bleeding is an issue,

Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. Care of the Coronary Artery Bypass Graft Patient 115 drugs such as protamine sulfate (to reverse the effects Postoperative Renal Management of heparin) or antifibrinolytic agents such as amino- There is a potential for renal dysfunction in the caproic acid or desmopressin (DDAVP) may be postoperative cardiac surgery patient. One reference ordered.22 Blood products such as fresh frozen suggests that the incidence is approximately 8%.1 plasma and platelets may also be ordered. Renal insufficiency may be related to advanced age, When bleeding occurs there is potential for the hypertension, diabetes, decreased function of the left blood to accumulate in the pericardium, and there- ventricle, and length of time on the CPB.25 One fore, the nurse must be cognizant of the potential for indicator of effective CO is adequate renal perfusion cardiac tamponade. The clinical manifestations of as evidenced by urinary output of at least 0.5 mL/kg/h. cardiac tamponade include lack of chest tube drain- The nurse must monitor the urinary output at least age, decreased BP, narrowed pulse pressure, increased hourly during the early postoperative period. The heart rate, jugular venous distention, elevated central urine should be assessed for color and characteristics venous pressure, and muffled heart sounds.13 Emer- as well as amount. Diuresis is likely in the post- gency reoperation would be required. operative period when renal function is adequate, as the fluids mobilize from the interstitial to the intra- Postoperative Neurologic Management vascular space. The patient’s potassium level should be monitored at least every 4 to 6 hours for the first Patients who require coronary artery bypass surgery 24 hours, as potassium is lost with diuresis. Intra- are at an increased risk for neurologic complications. venous potassium replacement should be adminis- Stroke can be caused by hypoperfusion or an tered to keep the serum potassium levels within embolic event during or after surgery. Manipulation normal limits. The patient should be astutely moni- of the aorta has been implicated in embolic events.23 tored for cardiac dysrhythmias if the serum potas- Other risk factors for stroke may include age, sium level is abnormal. Other laboratory values that previous stroke, carotid bruits, and hypertension.24 should be monitored at least daily are the blood urea The incidence of stroke is approximately 2.5%.23 nitrogen and serum creatinine. The nurse should be particularly astute to neurologic assessment in the postoperative period. When the patient is admitted to the intensive care unit, he/ Postoperative Gastrointestinal she will likely be intubated and unconscious. The Management effects of the neuromuscular blocking agents will be apparent. Pupils should be assessed initially, how- Gastrointestinal complications range from 0.12% to ever, normal size and reactivity may not return until 2%.26 Complications include peptic ulcer disease, agents utilized intraoperatively have been metabo- perforated ulcer, pancreatitis, acute cholecystitis, lized. Over the first few hours after surgery, the bowel ischemia, diverticulitis, and liver dysfunction. results of the neurologic assessment should improve Some risk factors for gastrointestinal dysfunction gradually. By the time the patient is ready for include age over 70, a history of gastrointestinal extubation, he/she should follow commands and disease, a history of alcohol misuse, cigarette smok- have equal movement and strength of the extremities ing, heart valve surgery, emergent operation, pro- with neurologic function approaching the patient’s longed CPB, postoperative hemorrhage, use of normal. It is difficult for significant others during vasopressors, and low postoperative CO.26 If the this time because waiting during the awakening gastroepiploic artery is used as a conduit for bypass, process can be anxiety provoking. Patients and sig- this may also increase the risk of gastrointestinal nificant others are informed prior to surgery of the dysfunction. Anesthetic agents, analgesics, and hypo- risk for stroke and want that to be definitively ruled perfusion of the gut during surgery can also contrib- out as soon as the patient returns to the intensive ute to gastrointestinal dysfunction. The nurse should care unit. The nurse should provide needed comfort monitor the patient for bowel sounds, abdominal but not give false hope, as the neurologic status distention, and nausea and vomiting. The intubated cannot be completely assessed until the patient is patient will have a nasogastric tube to low inter- fully awake and extubated. At that time, the patient mittent suction or Salem sump to continuous suc- should be assessed for orientation to person, place, tion. Placement and patency should be assessed as time, and circumstance. A motor and sensory assess- well as amount, color, and characteristics of the ment should also be performed. A positive result is a drainage. Prior to extubation, if bowel sounds are good indication that an intraoperative stroke can be present, the nasogastric tube will be discontinued ruled out. Neurologic assessments must continue and the nurse should continue to assess the patient because the risk of stroke does not end with the for potential gastrointestinal disturbances. The nurse operation.24 should administer antiemetic agents as ordered if the

Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. 116 Journal of Cardiovascular Nursing x March/April 2006 patient is nauseated. The comfort of the patient as 24 to 48 hours postoperatively when the amount well as the sterility of the sternal dressing must be and characteristics of chest tube drainage meet or- maintained. Some surgeons order a histamine blocker dered parameters as long as there is no air leak noted to minimize acid secretion until normal dietary pat- in the water seal chamber. Pain medication should be terns are resumed. When the nasogastric tube is administered prior to removal of chest tubes per removed, the patient will be started on a clear liquid institution protocol to minimize the trauma of the diet and this can be advanced as tolerated by the procedure. patient. Additional Postoperative Management Postoperative Pain Management The incidence of infection of sternal and leg incisions Dependent upon surgical approach, the patient may after cardiac surgery is less than 3%.13 Risk factors have a median sternotomy incision, leg incision(s), for infection include diabetes, malnutrition, chronic and/or a radial incision. Manipulation of the chest diseases, and patients requiring emergent surgery or cavity, use of retractors during surgery, and electro- prolonged surgery. Assessment for, and prevention cautery may all contribute to postoperative pain.27 of, infection is part of the nurse’s role in the post- In addition, positioning on the operating room table operative period. The patient should be assessed for and length of time of the surgery may also be factors local and systemic signs of infection. Postoperative in pain experienced postoperatively. antibiotics may be ordered. Dressings should be re- Poorly controlled pain can stimulate the sympa- moved and incision care should be completed thetic nervous system and lead to cardiovascular according to institution protocols. Control of blood consequences. The heart rate and BP can increase glucose level may help with prevention of infection. and the blood vessels can constrict, causing an It is desirable to control blood glucose levels of increase in the cardiac workload and myocardial greater than 150 mg/dL with a continuous intra- oxygen demand.27 Effective pain control is essential venous infusion of insulin versus intermittent sub- for patient comfort, hemodynamic stability, and cutaneous insulin injections. This practice is thought prevention of pulmonary complications. to be helpful in the prevention of deep sternal wound Nurses must individualize pain assessment and infection.1 control for each patient as responses vary among Some surgeons order corticosteroids postopera- individuals.27 Opioid analgesics, positioning, mobi- tively. When used, these drugs are intended to lization, distraction, and relaxation techniques are minimize the potential risks of inflammation after among some of the methods of pain control. Keeping heart surgery. Patients should be monitored for serum levels of opioid analgesics in the therapeutic suppression of the immune system, as this can be range is beneficial. Nonsteroidal anti-inflammatory an adverse effect of corticosteroid administration. agents may be used in conjunction with opioid Patients need to be taught how to slowly discontinue agents to control pain and minimize the amount of the medication after discharge per physician orders. narcotic needed. Ketorolac is a nonsteroidal anti- The other potential effect of corticosteroid adminis- inflammatory agent that can be administered intra- tration is an elevation in serum glucose levels. A venously in the early postoperative period while the sliding scale insulin order may be needed to maintain patient is still intubated. The nurse must monitor blood glucose levels within normal limits while the renal status of patients taking ketorolac, and the patient is in the hospital. drug may be discontinued if the serum creatinine is The nurse must intensively care for the patient in elevated. The patient is at an increased risk of gas- the early postoperative period. This intensive moni- trointestinal bleeding when a nonsteroidal anti- toring and postoperative discomfort can interfere inflammatory agent is used. Pulmonary care is more with the patient’s need for sleep. There is a potential effective for the patient when pain is effectively for sleep disturbance as the patient is recovering managed. Teaching the patient to splint the incision from CABG. Lack of sleep may negatively affect when coughing and moving improves pain control. postoperative outcomes.28 Organization of needed The nurse should evaluate the effectiveness of pain care and provision of time for uninterrupted sleep management interventions regularly. Significant cycles is important for effective outcomes. Some of others are often concerned about the postoperative the postoperative confusion experienced by patients pain experienced by the patient. Explanations about may be minimized and positive outcomes maximized interventions utilized and outcomes achieved can when time for sleep is provided. Hospital routines decrease anxiety. and too many visits by well-meaning significant Another source of pain for the patient after CABG others may add to the sleep deprivation problem. is the removal of the chest tubes. This usually occurs Significant others should be able to spend time with

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