Page 629 - Cardiac Nursing

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C HAPTER 2 5 / Cardiac Surgery 605
Pulmonary antibiotics and digoxin, must be adjusted for decreased renal
Routinely, patients are intubated and ventilated for 2 to 4 hours clearance. When renal failure after cardiac surgery is severe
after cardiac surgery. Pulmonary function is monitored with con- enough to require renal replacement therapy, the mortality rate is
tinuous pulse oximetry as well as intermittent arterial blood gases close to 60%. 46
and chest radiographs. Mild pulmonary dysfunction is common
after cardiac surgery. Pathophysiologic changes that occur after Gastrointestinal
CPB include increased capillary permeability, increased pul- Serious gastrointestinal complications can occur after cardiac
monary vascular resistance, and intrapulmonary aggregation of surgery. Abdominal distention can occur during the first days af-
leukocytes and platelets. A noncardiac pulmonary edema may oc- ter surgery secondary to decreased motility related to anesthesia,
cur immediately after CPB or during the first several days after narcotics, and diabetic gastroparesis. If ileus and abdominal dis-
surgery. Comparative studies between OPCAB and CABG with tention do not resolve with fasting and suppository or enema
CPB suggest that CPB alone may not be the major cause of the treatments, the etiology of the distention should be explored
9
development of postoperative pulmonary dysfunction. In a further. Gastroduodenal bleeding can result from erosive gastri-
43
prospective, controlled trial by Roosens et al., both patients with tis or esophagitis, or frank ulceration, especially in patients with
and without CPB had dramatic impairment of respiratory system a previous history of peptic ulcer disease. Patients after cardiac
mechanic postoperatively. Severe pulmonary dysfunction is un- surgery usually are placed on prophylactic gastrointestinal agents
common and may be related to preexisting lung disease. Although such as antacids, sucralfate, histamine blockers such as famoti-
severe lung injury after cardiac surgery is rare, it continues to be a dine or ranitidine, or proton-pump inhibitors such as pantopra-
major impact on morbidity and mortality as well as related cost of zole. Cholecystitis presents with right upper quadrant pain and
9
hospitalization. In a case controlled study by Milot et al. 44 in can be evaluated with abdominal ultrasound. After cardiac
3,278 patients, adult respiratory distress syndrome after cardiac surgery or critical illness, cholecystitis commonly occurs in its
surgery was rare (0.4%) but carried a 15% mortality rate. Inde- acalculous (no stones) form. Mild elevations of hepatic transam-
pendent predicators of adult respiratory distress syndrome in car- inases also occur commonly after CPB. Severe hepatic dysfunc-
diac surgery patients include number of blood products trans- tion or “shock liver syndrome” with massive increases in liver en-
fused, shock, and previous cardiac surgery. 44 Chest radiographs zymes most often occurs as a result of global hypoperfusion and
should be performed as part of the fever work-up to rule out at- end-organ damage. Acute hemorrhagic pancreatitis is uncom-
electasis and pneumonia. Atelectasis may occur secondary to hy- mon after CABG surgery, but it has high rates of mortality and
poventilation related to sternal incision discomfort. Pain from morbidity. If the patient continues to remain acidotic and the
chest tubes and sternotomy incision interferes with normal respi- diagnostic work-up fails to identify another cause, abdominal
ration and pulmonary toilet, making adequate pain control a high exploration is done in the hope of finding a correctable source
priority. Diminished breath sounds and lung fields at the bases such as necrotic bowel. Diarrhea may occur with enteral feed-
that are dull to percussion indicate significant pleural effusions. ings and medications such as quinidine or procainamide, or may
Pneumothorax may occur any time during the postoperative pe- be the result of Clostridium difficile infection. Patients with diar-
riod or at the time of pleural chest tube removal. Phrenic nerve rhea should have stool samples sent to test for C. difficile toxin
damage may result in diaphragmatic paralysis or dysfunction but and are treated with oral administration of metronidazole or
is uncommon with today’s surgical techniques. vancomycin.
Pulmonary embolism is uncommon after cardiac surgery. Fac-
tors associated with a higher incidence of pulmonary emboli in- Neuropsychological
clude AF, heart failure, obesity, hypercoagulable states, and im- Neuropsychological dysfunction after cardiac surgery can be ei-
mobilization. Diagnostic work-up for pulmonary emboli includes ther central or peripheral. Cognitive decline after CPB has been
arterial blood gas, ventilation perfusion scan, CT scan, or pul- estimated from 3% to 50%, depending on definitions and time of
monary angiogram. Treatment with continuous intravenous he- assessment and stroke in approximately 3% of patients undergo-
parin is begun once the diagnosis of pulmonary emboli is estab- ing CABG surgery. 18 Embolization is the most common etiology
lished, and warfarin is started for long-term anticoagulation. In of stroke during cardiac surgery but hypoperfusion may also play
patients in whom anticoagulation is contraindicated, an inferior a role. 47
vena caval filter may be placed. Surgical pulmonary embolectomy Two types of peripheral neurologic deficits, brachial plexus in-
may be used in patients with large pulmonary emboli and associ- jury and ulnar nerve injury, are described after cardiac surgery.
ated clinical presentation of right-side heart failure. The brachial plexus is susceptible to stretch injury and can occur
48
with sternal retraction is a key factor responsible for injury. In
Renal addition to a history of upper extremity pain and paresthesia, ex-
While the pathogenesis of renal failure after cardiac surgery is amination for brachial plexus injury includes evaluation of motor
multifactorial, CPB represents a specific risk. 45 Radiocontrast function of muscle groups innervated by the brachial plexus and
48
used during coronary angiography before cardiac surgery can fur- sensation to pin prick. Ulnar nerve injury, a result of nerve com-
ther reduce renal function. Nonoliguric renal failure after cardiac pression, is frequently described by patients after cardiac surgery
surgery occurs most commonly after cardiac surgery. If renal dys- as paresthesias in the affected arm below the elbow in the ulnar
function progresses to oliguric renal failure, serum potassium lev- distribution involving the third, fourth, and fifth digits.
els may increase rapidly and maintenance of normovolemia may Postcardiotomy delirium occurs 2 to 5 days after cardiac sur-
be difficult without hemofiltration or dialysis. Nephrotoxic med- gery and is manifested as mild confusion, somnolence, agitation,
ications such as aminoglycoside antibiotics, radiographic contrast, or hallucinations. Memory and alertness are frequently preserved
and nonsteroidal anti-inflammatory drugs must be avoided in but psychosis may occur. 47 While postcardiotomy delirium is
postoperative renal failure, and many other medications, such as usually self-limiting, it may put the patient at increased risk for