Pre-operative management in cardio-thoracic surgeries.

Introduction:

Despite technological advances that have made operations quicker, safer, and more effective, surgery remains one of the stressful experiences a patient can undergo. Before the patient enters the operating room, you’ll need to fully address his psychological as well as physiologic needs. After all, surgical patients, if prepared through careful teaching, will experience less pain and fewer postoperative complications and have shorter hospitalizations.

Preoperative management of cardio-thoracic surgical patients includes both physical and psychological preparation for the planned operation. Although much of the preparatory management is standard, some important differences exist depending on the specific disease necessitating surgical intervention. Before any cardio-thoracic surgeries, the surgeon, anesthesiologist, and advanced practice nurse (1) interview and assess the patient; (2) review all the diagnostic information, including laboratory, electrocardiographic, chest radiographic, and cardiac catheterization data; and (3) prepare the patient for planned operation and postoperative regimen. Typically, this preoperative preparation is performed in an outpatient setting and the patient is admitted to the hospital on the morning of the planned operation. Same-day admission for a cardiac operation requires efficient organization of the system so that necessary evaluation can be accomplished and diagnostic studies reviewed appropriately.

For selected patients with special needs, preoperative hospitalization may be necessary to allow time for interventions that decrease operative risk. For example, patients with valvular heart disease and severe ventricular dysfunction may require preoperative diuresis guided by pulmonary artery pressure monitoring because of the narrow window between adequate preload and pulmonary edema. Patients with severe, long-standing cardiac disease also may have protein and calorie malnutrition requiring preoperative nutritional supplementation.

• Preoperative Evaluation/ Assessment:

The preoperative nursing evaluation complements that performed by the physician and provides baseline information that enhances interpretation of postoperative findings. It also allows the nurse to establish a relationship with the patient and family and identify potential problems that may occur during the peri-operative period. Information for the pre-operative evaluation is obtained from the patient record, interview with physical examination of the patient, and diagnostic studies.

Patient interview:

The pre-operative interview is used to obtain baseline information about the patient’s clinical history, understanding of the illness, emotional readiness for the planned procedure, and family support system

Important features include:

• History of present illness (i.e., the type of heart disease and associated symptoms).

• Presence of cardiac risk factors.

• Associated medical diseases, such as cerebrovascualr or other peripheral arterial occlusive disease, hypertension, diabetes, peptic ulcer disease, or COPD.

• Current medication regimen & any known allergies.

• Degree of functional impairment associated with the cardiac disease.

Other pertinent information includes the patient’s occupation and personal habits, such as smoking, alcohol use, exercise, and diet.

Information from the clinical history may reveal factors that increase preoperative risk. It may also alter the planned peri operative therapy. for example, detection of transient ischemic attacks may necessitate further preoperative evaluation of the carotid arteries and possible combined or staged surgical therapy. A history of GI bleeding or peptic ulcer disease may influence the antiplatelet regimen after coronary artery revascularization or the choice of valvular prosthesis.

The patients living arrangements are addressed during the interview so that appropriate discharge planning can be initiated. An increasing number of surgical patients are elderly and have limited social and financial resources. Identification of discharge needs before hospitalization alleviates anxiety for the patient and family and makes discharge from the hospital more efficient and timely.

Physical assessment:

Physical examination of the cardio-thoracic surgical patient focuses particularly on the pulmonary and cardiovascular systems, mainly heart, lungs, peripheral pulses, neck and extremities.

• The lungs are auscultated to provide baseline data regarding respiratory rate, breath sounds, or the presence of adventitious sounds. Rales may indicate the need for preoperative diuresis. Rhonchi in a heavy smoker may warrant preoperative bronchodilator therapy and pulmonary hygiene measures.

• Heart sounds are auscultated, and the cardiac rate, rhythm, and any extra sounds, or murmurs are noted.

• Blood pressure, temperature, and weight are measured, and peripheral pulses are palpated.

• Each of the carotid arteries is auscultated from the base of the neck to the angle of the jaw, with the patient holding his breath. The presence of carotid bruit (i.e., audible sound associated with turbulent flow) often represents arterial stenosis at or proximal to the site of auscultation and usually is loudest in the upper third of the neck in the area of the carotid bifurcation.

• Palpation of the abdomen may allow detection of an abdominal aortic aneurysm, except in markedly obese patients.

• Peripheral pulses are assessed as well as other indicators of peripheral perfusion. Ankle blood pressure measurements are obtained to provide baseline information about adequacy of arterial blood flow to the lower extremities.

• Any abnormalities, such as jugular venous distension, ascitis, or peripheral edema, are noted. The presence of varicose veins or thrombophlebitis is significant in patients who are to undergo coronary artery revascularization.

• Other findings of significance during the pre-operative physical examination include dental infection, which increases risk of endocarditis in patients with valvular heart disease, or prior radical mastectomy, which may preclude use of an internal thoracic artery.

Signs and symptoms of heart disease:

Special consideration is given during the preoperative assessment to the presence of signs and symptoms of organic heart disease.

1. Angina pectoris, its cardinal manifestation, probably is the most frequently encountered symptom in preoperative cardiac surgical patients. Angina that is accelerating represents an acute coronary syndrome. It is reported promptly to the surgeon and requires increased antianginal therapy or admission to the hospital. Myocardial ischemia that is unrecognized or unrelieved can lead to death, irreversible muscle damage, or complications, such as arrhythmias or cardiogenic shock.

2. Chest pain can occur because of other etiologies, but in preoperative patients all chest pain is assumed ischemic until proven otherwise. Pain due to reflux frequently occurs after eating and is relieved by antacids. Pleuritis secondary to pleural inflammation also can cause chest pain. Musculoskeletal chest pain differs from angina in that it usually is well localized and the painful area is tender to palpation. Chest pain caused by anxiety may assume any form, although it frequently occurs as a dull ache in the left inflammatory hemi thorax. It is persistent and often is associated with fleeting sharp pains or a sensation of anxiety or breathlessness.

3. Dyspnea is a second common symptom of organic heart disease. It should be regarded abnormal only when it occurs at rest or with a level of activity not expected to produce dyspnea. Paroxysmal nocturnal dyspnea most commonly represents left-sided heart failure.

4. Less common manifestations of cardiac disease in adults include syncope, palpitations, cough, hemoptysis, hoarseness, nocturia, fatigue, cyanosis and peripheral edema.

5. Cardiac arrhythmias are common in patients with organic heart disease. Preoperative ventricular tachycardia may represent acute myocardial ischemia or an underlying chronic rhythm disorder that requires electrophysiological evaluation.

• Preparatory Interventions:

Diagnostic studies:

• Diagnostic studies performed routinely during the preoperative period include a complete blood count with differential, hemostasis studies (prothrombin time, partial thromboplastin time, and platelet count), blood chemistry survey, blood clotting studies, urinalysis, electrocardiogram, and chest roentgenogram. These baseline studies typically are performed within 1 week of the planned operation and are essential to detect any abnormalities that could increase operative risk or alter the plan of therapy.

• In patients with signs and symptoms of ischemic heart disease, exercise testing may be performed to detect myocardial ischemia before proceeding with a planned thoracic operation. Arrhythmias or congestive heart failure also may require diagnostic evaluation and treatment before operation.

• Room air arterial blood gases typically are measured to identify arterial hypoxemia or carbon dioxide retention and to provide a baseline for comparison with postoperative measurements. Arterial hypercapnia is considered an indicator of significantly increased risk of respiratory failure and operative death; arterial hypoxemia also is correlated with an increased risk of complications.

• In patients with pulmonary neoplasms, a stool specimen may be obtained to test for the presence of blood. Occult blood in the stool might indicate that the lung lesion is not a primary tumor but rather an adenocarcinoma of the bowel that is metastasized to the lung.

• In patients who will undergo pulmonary resection, pulmonary function testing usually is performed to assess the patient’s ability to withstand removal of a portion of functional lung tissue. Pulmonary function testing identifies patients at high risk for pulmonary complications and allows implementation of prophylactic interventions in the preoperative period.

• A non invasive carotid ultrasound study is obtained if the patient has a carotid bruit or a history of a transient ischemic attack or CVA. A Doppler arterial blood flow study of the lower extremities may be obtained in patients with claudication or evidence of limb ischemia. Venous duplex scanning may be performed in selected patients undergoing coronary artery revascularization to assess the quality of venous conduit for grafting.

• Before cardiac valve replacement, patients usually undergo a dental evaluation with dental roentgenograms. Because dental infection is a common source of bacterial endocarditis, infected teeth are extracted and oral abscesses drained before implantation of a valvular prosthesis. in patients with valvular dysfunction, appropriate antibiotic prophylaxis is administered before any dental procedures likely to cause bleeding from hard or soft tissues, periodontal surgery, scaling or professional cleaning of teeth.

• Patients with intrathoracic lesions often have undergone bronchoscopy, chest computed tomography, or MRI as part of the diagnostic evaluation.

• Sometimes cardiac surgery is delayed because of diagnostic studies. for example, consideration is given to nephrotoxic effects of angiographic contrast material used during cardiac catheterization. Operation is delayed if the screening urinalysis reveals a urinary tract infection. If an unexpected malignancy is diagnosed, the operation may be postponed or canceled, depending on the urgency of the cardiac problem and the nature and extent of the malignancy.

Medication:

Most medications, with the exception of anticoagulant and antiplatelet agents, are continued throughout the preoperative period until the time of surgery. This includes maintenance antihypertensive, antiarrythmics, antianginal, and antiseizure agents.

• Withdrawal of antihypertensive medications can lead to rebound hypertension or intraoperative blood pressure lability.

• Acute discontinuation of beta-adrenergic blocking agents can result in hyper sympathetic state, precipitating myocardial ischemia or infarction or arrhythmias.

• In patient receiving the calcium channel antagonists diltiazem or verapamil, the preoperative dose may need to be reduced to avoid postoperative bradycardia and low cardiac output syndrome.

• Digoxin sometimes is administered prophylactically before major pulmonary or esophageal resection procedures because of the prevalence of postoperative supraventricular tachycardia. Achieving a therapeutic serum digoxin level before operation may not prevent occurrence of tachyarrhythmias, but it is believed by some to facilitate control of the ventricular response rate if the arrhythmia occurs.

• Medications that affect hemostasis are discontinued. Warfarin sodium is usually withheld for 3 to 5 days before a planned operation so that prothrombin time gradually decreases towards a normal level. Depending on the indication for warfarin, it may be necessary to administer heparin intravenously or enoxaparin sodium (Lovenox) subcutaneously during this period to prevent serious thrombotic or thromboembolic complications. Because of its short half-life, heparin usually is continued until the morning of the operation or, if the patient has unstable angina, until transport to the operating room.

• Most patients who undergo coronary artery revascularization are receiving aspirin. Because aspirin irreversibly inhibits platelet function, aspirin ingestion within 1 week before surgery is associated with increased perioperative bleeding that may necessitate blood transfusions or any aspirin containing compound is usually discontinued a full week before an elective cardiac operation.

• Oral hypoglycemic agents usually are withheld from diabetic patients on the day of surgery. In insulin dependent patients, the insulin dosage is adjusted because food and fluids are withheld for 8 to 12hrs before operation.

• In patients receiving preoperative steroids, an intravenous steroid are administered during and after surgery until oral steroid is resumed. Abrupt cessation of corticosteroids in patients who have been on chronic steroid therapy can lead to acute adrenal insufficiency.

• A preoperative dose of antibiotics may be administered to reduce the likelihood of perioperative infection, although many surgeons administer several postoperative doses only. A broad-spectrum agent, such as a cephalosporin, typically is selected.

Blood preparation:

Blood transfusion for cardiac operations is complex because of the risk of transmitting hepatitis B, C or HIV through allogeneic blood transfusions.

If it is possible to schedule the operation several weeks in advance and if the patient’s medical condition permits, autologous donation may be performed.

Category: Surgery Notes