Cardiac Anesthesia Events

Definition

A cardiac laceration is an inadvertent incision into the right atrium, right ventricle, great vessels, or vein graft(s) during sternotomy or resulting from other traumatic injury

Etiology

• Adhesion of scar tissue and/or myocardial tissue to the sternum

• CPR

• Penetrating chest trauma (e.g., gunshot wound, knife injury, MVA)

Typical Situations

• Patients who have had a previous sternotomy (“redo” sternotomy), especially those with vein grafts crossing under the sternum

• Inexperienced surgeon

• When the lungs are ventilated during sternotomy

• Emergency sternotomy

• Patients with ascending aortic aneurysms or multivessel aortic arch disease

• Patients with an anatomic abnormality of the chest wall (kyphoscoliosis, pectus excavatum)

• Patients who have received mediastinal radiation

• Patients who have had CPR with rib or sternal fractures

• Patients with penetrating injury to the chest

• Patients following MVA

Prevention

• Obtain preoperative lateral CXR and/or CT scan to evaluate the extent of adhesions to the heart, great vessels, and sternum

• Stop ventilating the lungs prior to primary sternotomy; maintain ventilation at reduced tidal volumes during redo sternotomy

• Reduce myocardial chamber size during sternotomy

  • Place the patient in reverse Trendelenburg position

  • Vasodilate the patient with an IV infusion of sodium nitroprusside or NTG

• Consider instituting femoral artery−to−femoral vein CPB prior to sternotomy

• Suggest that sternotomy be performed following deep hypothermia and complete circulatory arrest if an aortic aneurysm is adherent to the underside of the sternum

Manifestations

• Large volumes of blood welling out of the surgical field or other site of injury

• Hypotension

  • May be due to blood loss

  • Acute cardiac failure may occur if a critical vein or internal mammary artery graft to a coronary artery is lacerated

• Tachycardia

• Obvious signs of chest trauma—knife or bullet holes, seat belt burns

• Hemopneumothorax

Similar Events

• Bleeding from other intrathoracic structures (see Event 1, Acute Hemorrhage )

• Hypotension from other causes (see Event 9, Hypotension )

Management

Cardiac laceration may occur during any sternotomy or chest trauma.

• In cardiac surgery, be prepared for major hemorrhage during sternotomy

  • Ensure adequate IV access is in place for redo sternotomy

  • If a blood salvage device is to be used during surgery, have it set up prior to sternotomy

  • Stop ventilating the lungs prior to primary sternotomy; maintain ventilation at reduced tidal volumes during redo sternotomy

  • Ensure at least two units of PRBCs are available in the OR prior to sternotomy

  • Observe the operative field carefully during sternotomy

  • Ensure rapid fluid infuser is available

• If major hemorrhage is apparent during sternotomy

  • Stop administering volatile anesthetics and flush the anesthesia breathing circuit with 100% O ₂

  • Increase FiO ₂ to 100% and resume ventilation

  • Stop administering vasodilators

• Maintain the circulating fluid volume

  • Administer IV fluid (crystalloid, colloid, blood)

  • Get help to administer volume rapidly

  • Hook up rapid fluid infuser

• Maintain perfusion pressure

  • Administer vasopressors as required (see Event 9, Hypotension )

    • Administer phenylephrine IV, 50 to 200 μg, and escalate as needed

    • Administer epinephrine IV, 10 to 50 μg, and escalate as needed

• Conserve the patient’s blood

  • Ensure that the blood salvage device is used by the surgeons

• If surgical repair on CPB is necessary

  • Heparin should be administered (300 to 400 units/kg IV) by the anesthesiologist through a central line

    • Check ACT as soon as feasible

    • Administer more heparin if ACT is less than 400 seconds

  • After heparinization, blood can be salvaged by the cardiotomy suction line of the CPB pump (“sucker bypass”)

  • The femoral artery may have to be cannulated for the arterial perfusion line

  • A right ventriculotomy and the cardiotomy suction can be used as venous return for CPB

• After CPB is initiated, anticipate and plan for problems associated with prolonged CPB time and myocardial injury (see Event 78, Low Cardiac Output State After Cardiopulmonary Bypass ; Event 75, Coagulopathy Following Cardiopulmonary Bypass ; and Event 15, Acute Coronary Syndrome )

• Following penetrating or blunt injury to the chest or in patients who have had CPR, patients may need

  • Chest tube placement

  • Fluid resuscitation

  • Sternotomy/thoracotomy to control bleeding and/or cross-clamping of the descending aorta

  • Transfer to the OR for definitive surgery

Complications

• Failure to wean from CPB

• Acute myocardial failure

• Myocardial ischemia

• Arrhythmias

• Cardiac arrest

• ARDS

• Hypothermia

• Systemic air embolism

Definition

Coagulopathy following CPB as a result of deficiency or dysfunction of platelets or of the coagulation cascade

Etiology

• Circulating anticoagulant

  • Inadequate heparin neutralization

  • Heparin rebound

  • Protamine overdose

• Thrombocytopenia

• Impaired platelet function

• Low plasma concentrations of coagulation factors

• DIC

• Primary fibrinolysis

• Preexisting congenital or acquired coagulopathy

Typical Situations

• Postoperative cardiac surgery patients

• Prolonged time on CPB

  • Increased platelet activation

  • Thrombocytopenia

  • Consumption of coagulation factors

• Massive hemorrhage or transfusion

• Vigorous cardiotomy suction

• Patients requiring a circulatory assist device

• Patients undergoing deep hypothermia (core temperature below 20° C)

• Preexisting coagulopathy

  • Drug therapy inhibiting platelet function (aspirin, dipyridamole, clopidogrel)

  • Anticoagulant therapy

  • Thrombolytic therapy (streptokinase or similar agents)

  • Hepatic dysfunction

  • Chronic renal failure

  • Myeloproliferative disorders

Prevention

• Identify patients with preexisting clinical, subclinical, or pharmacologically induced coagulation disorders

  • Obtain preoperative laboratory studies of coagulation function

    • PT, PTT

    • Platelet count

    • Thromboelastogram, if available

• Keep CPB time as short as possible

• Minimize the negative pressure applied to the cardiotomy suction to reduce platelet trauma

• Administer heparin and protamine in appropriate doses

  • Monitor coagulation during and immediately after CPB

  • Maintain adequate anticoagulation during CPB (ACT > 400 seconds)

• Consider the use of acute normovolemic hemodilution (remove whole blood pre-CPB for retransfusion post-CPB)

• Coordinate the discontinuation of preoperative medications known to cause platelet dysfunction with the surgical team

• Consider administering pharmacologic therapy in high-risk cases

  • ε-Aminocaproic acid

  • Tranexamic acid

• Have blood products available at the end of CPB for patients at high risk of a coagulopathy

  • Patients who have had previous cardiac surgery

  • Duration of CPB longer than 3 hours

Manifestations

• Bleeding into the surgical field from multiple sites and from wound edges after administration of an adequate dose of protamine

• Increased mediastinal chest tube output after the chest has been closed

• Bleeding from IV insertion sites, wounds, or mucous membranes

• Abnormalities in laboratory tests of coagulation function

  • Prolonged ACT that does not correct with additional protamine

  • Thrombocytopenia

  • Prolonged PT and PTT

  • Decreased fibrinogen level

  • Increased levels of fibrin split products

  • Abnormal thromboelastogram

• Hypotension, tachycardia

• Cardiac tamponade

Similar Events

• Surgical bleeding

• Acute hemorrhage (see Event 1, Acute Hemorrhage )

• Transfusion reaction (see Event 50, Transfusion Reaction )

• Cardiac tamponade from other causes (see Event 18, Cardiac Tamponade )

Management

• Surgical exploration is indicated if

  • The mediastinal chest tube drainage exceeds 300 to 400 mL in 1 hour, drainage is continuing, and laboratory tests of coagulation are normal

  • Signs of cardiac tamponade are occurring (see Event 18, Cardiac Tamponade )

    • Equilibration of filling pressures

    • TEE/TTE examination is suggestive of cardiac tamponade

  • Provide supportive therapy until bleeding is controlled

  • Maintain the circulating fluid volume

    • Infuse crystalloid, colloid, and blood products as necessary to maintain perfusion pressure

  • Administer vasopressors as required to maintain perfusion pressure (see Event 9, Hypotension )

    • Phenylephrine IV, 50 to 100 μg, and escalate as needed

    • Epinephrine IV, 10 to 50 μg, and escalate as needed

  • Maintain normothermia (see Event 44, Hypothermia )

    • Use heating blankets and/or a forced-air warming device

    • Warm all IV fluids

  • Prevent hypertension

    • Maintain adequate sedation

    • Administer vasodilator agents as needed

  • Consider PEEP to decrease the amount of venous mediastinal bleeding following chest closure

• Assess laboratory tests of coagulation function

  • Check the ACT

    • Administer additional protamine until the ACT returns to control or until there is no further reduction in the ACT

  • Send samples to the clinical laboratory for

    • Platelet count

    • PT

    • PTT

    • Fibrinogen

    • Fibrin split products

  • Check thromboelastogram

• Begin empirical therapy while waiting for laboratory results if bleeding is severe (see Event 1, Acute Hemorrhage )

  • Restore platelet numbers and function

    • Reinfuse any fresh whole blood removed from the patient prior to CPB after administration of protamine

    • Administer platelets (one apheresis unit should increase platelet count by 50,000 to 80,000/μL)

    • Consider desmopressin (DDAVP) IV by slow infusion, 0.3 μg/kg. Can cause hypotension if given too quickly

  • Infuse 2 to 4 units of fresh frozen plasma (adults)

  • Further use of blood products should be guided by laboratory results if practical

  • Consult a hematologist for further management of a coagulopathy that does not resolve

  • Consider recombinant factor VIIa IV, 15 to 180 μg/kg (dosage for the treatment of uncontrolled hemorrhage in nonhemophiliac patients vary; consult a hematologist)

• If primary fibrinolysis is thought to be the cause of bleeding

  • Administer ε-aminocaproic acid IV, 5 g bolus infusion followed by 1 g/hr for 6 hours

Complications

• Transfusion reaction

• Hypovolemia

• Hypervolemia

• DIC

• Hypercoagulable states

• Renal failure

• Mediastinitis following reexploration

• Bloodborne virus infection

• Death

Definition

Emergent initiation of CPB