COMPLICATIONS OF CARDIAC SURGERY

Prepared by-:2-Mustafa Flayyih Abd

A- Decrease cardiac output 1-(Hypovolemia)2 Bleeding3- Cardiac Tamponade4- Fluid overload5-Hypothemia6-Hypertension7-Tachydysrhythmias8-Bradycardias9-Cardiac Failure

10-Mayocardial InfarctionB -Pulmonary Complications:-C - Neurologic change and StrokeD - Renal Failure and Electrolyte Imbalance:-1- Acute Renal Failure2-Electolyte ImbalanceE - Other complications :-1-Hepatic Failure2- Infection

Decreased Cardiac Output

•Hypovolemia (most common cause of decreased cardiac output after cardiac surgery)

CAUSES

• Net loss of blood and intravascular volume.• Surgical hypothermia (as the reduced body temperature rises after surgery, blood vessels dilate, and more volume is needed to fill the vessels).• Intravenous fluid loss to the interstitial spaces because surgery and anesthesia increase capillary permeability.

Assessment and Management• Arterial hypotension, tachycardia, low central venous pressure (CVP)

and low pulmonary artery wedge pressure (PAWP) are often seen.

• Fluid replacement may be prescribed. Replacement fluids include colloid (albumin, hetastarch), packed red blood cells, or crystalloid solution (normal saline, lactated Ringer’s solution).

Persistent bleeding

Causes• Cardiopulmonary bypass causes platelet dysfunction, and

hypothermia alters clotting mechanisms.• Surgical trauma causes tissues and blood vessels to ooze bloody

drainage.• Intraoperative anticoagulant (heparin) therapy.• Postoperative coagulopathy may also result from liver dysfunction

and depletion of clotting components.

Assessment and Management• Accurate measurement of wound bleeding and chest tube blood is

essential. Drainage should not exceed 200 mL/h for the first 4 to 6 hours. Drainage should decrease and stop within a few days.• Serial hemoglobin, hematocrit, and coagulation studies are performed

to guide therapy.• Administration of fluids, colloids, and blood products: packed red blood

cells, fresh frozen plasma, platelet concentrate.• Protamine sulfate may be administered to neutralize unfractionated

heparin.• Administration of desmopressin acetate (DDAVP) to enhance platelet

function.• If bleeding persists, the patient may return to the operating room.

Cardiac Tamponade

Causes•Fluid and clots accumulate in the pericardial sac, which compress the heart, preventing blood from filling the ventricles.

Assessment and Management• Signs and symptoms include arterial hypotension, tachycardia,

muffled heart sounds, decreased urine output, and c CVP. Arterial pressure waveform may show pulsus paradoxus (decrease of more than 10 mm Hg systolic blood pressure during inspiration).• The chest drainage system is checked to eliminate possible kinks or

obstructions in the tubing.• Chest x-ray may show a widening mediastinum.• Emergency medical management is required; may include return to

surgery.

pulsus paradoxus

Fluid overload• Intravenous (IV) fluids and blood products increase

circulating volume.

Assessment and Management• High CVP and pulmonary artery pressures as well as crackles

indicate fluid overload.• Diuretics are prescribed and the rate of IV fluid administration is reduced.• Alternative treatments include continuous renal replacement therapy and dialysis.• Patient is rewarmed gradually after surgery, decreasing vasoconstriction.

Hypothermia

•Low body temperature leads to vasoconstriction, shivering, and arterial hypertension.

Assessment and Management•Patient is rewarmed gradually after surgery,

decreasing vasoconstriction.

Hypertension•Results from postoperative vasoconstriction. It may

stretch suture lines and cause postoperative bleeding. The condition is usually transient.

Assessment and Management•Vasodilators (nitroglycerin [Tridil], nitroprusside

[Nipride]) may be used to treat hypertension.•Administer cautiously to avoid hypotension.

Tachydysrhythmias• Increased heart rate is common with perioperative volume changes. Uncontrolled atrial fibrillation commonly occurs during the first few days postoperatively.

Assessment and Management• If a tachydysrhythmia is the primary problem, the heart rhythm is

assessed and medications (eg, amiodarone [Cordarone], diltiazem [Cardizem], may be prescribed.• Antidysrhythmic agents may be given before coronary artery bypass

graft (CABG) to minimize the risk of postoperative tachydysrhythmias.• Carotid massage may be performed by a physician to assist with

diagnosing or treating the dysrhythmia.• Cardioversion and defibrillation are alternatives for symptomatic tachydysrhythmias.

Bradycardias•Decreased heart rate due to surgical trauma and

edema affecting the cardiac conduction system.

Assessment and Management•Many postoperative patients have temporary pacer

wires that can be attached to a pulse generator (pacemaker) to stimulate the heart to beat faster. Less commonly, atropine or other medications may be used to increase heart rate.

Cardiac failure•Myocardial contractility may be decreased

perioperatively.

Assessment and Management• The nurse observes for and reports signs of heart

failure including hypotension, c CVP, c PAWP, venous distention; labored respirations; and edema.

• Medical management includes diuretics, digoxin, and IV inotropic agents.

Myocardial infarction (MI) (may occur intraoperativelyor postoperatively)•Portion of the cardiac muscle dies; therefore,

contractility decreases. Impaired ventricular wall motion further decreases cardiac output.• Symptoms may be masked by the postoperative

surgical discomfort or the anesthesia–analgesia regimen.

Assessment and Management•Careful assessment to determine the type of pain the

patient is experiencing; MI suspected if the mean blood pressure is low with normal preload.

• Serial electrocardiograms (ECGs) and cardiac biomarkers assist in making the diagnosis (alterations may be due to the surgical intervention).

Pulmonary Complications Impaired gas exchange•During and after anesthesia, patients require

mechanical assistance to breathe.• Anesthetic agents stimulate production of mucus and chest incision pain may decrease the effectiveness of ventilation.• Potential for postoperative atelectasis.

Assessment and Management•Pulmonary complications are detected during

assessment of breath sounds, oxygen saturation levels, arterial blood gases, and ventilator readings.

• Extended periods of mechanical ventilation may be required while complications are treated.

Neurologic Complications Neurologic changes; stroke• Thrombi and emboli may cause cerebral infarction

and neurological signs may be evident when patients recover from anesthesia.

Assessment and Management• Inability to follow simple commands within 6 hours

of recovery from anesthetic; weakness on one side of body or other neurological changes may indicate stroke.

• Patients who are elderly or who have renal or hepatic failure may take longer to recover from anesthesia.

Acute renal failure•May result from hypoperfusion of the kidneys or

from injury to the renal tubules by nephrotoxic drugs.

Assessment and Management•May respond to diuretics or may require continuous

renal replacement therapy (CRRT) or dialysis.• Fluids, electrolytes, and urine output are monitored

frequently.• Renal failure may become chronic and require

ongoing dialysis.

Electrolyte imbalance•Postoperative imbalances in potassium, magnesium,

sodium, calcium, and blood glucose are related to surgical losses, metabolic changes, and the administration of medications and IV fluids.

Assessment and Management•Monitor electrolytes and basic metabolic studies

frequently.• Implement treatment to correct electrolyte imbalance promptly

Infection• Surgery and anesthesia alter the patient’s immune

system. Multiple invasive devices used to monitor and support the patient’s recovery may serve as a source of infection.

Assessment and Management•Monitor for signs of possible infection: body temperature,

white blood cell and differential counts, incision and puncture sites, urine (clarity, color, and odor), bilateral breath sounds, sputum (color, odor, amount).

• Antibiotic therapy may be instituted or modified as necessary.• Invasive devices are discontinued as soon as they are no longer required. • Institutional protocols for maintaining and replacing invasive

lines and devices are followed to minimize the risk of infection.

Hepatic failure• Surgery and anesthesia stress the liver. Most common

in patients with cirrhosis, hepatitis, or prolonged right-sided heart failure.

Assessment and Management• Use of medications metabolized by the liver must be

minimized.• Bilirubin, albumin, and amylase levels are monitored, and nutritional support is provided.