Cardiac Laceration
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
Suggested Reading
Coagulopathy Following Cardiopulmonary Bypass
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
Suggested Reading
Emergent “Crash” onto Cardiopulmonary Bypass
Definition
Emergent initiation of CPB
Etiology
Cardiac surgery
Perioperative cardiac arrest, myocardial ischemia, hypotension, or massive hemorrhage
Airway catastrophe
Inability to establish an airway by routine methods (e.g., anterior mediastinal mass with tracheomalacia)
LAST requiring prolonged CPR
Typical Situations
Acute coronary graft occlusion
Failure of PCI
Severe valvular dysfunction
Failure of valve (e.g., ruptured chordae), valve repair or replacement
Endocarditis with acute severe valvular incompetence
Acute severe myocardial dysfunction
Severe hypotension
Severe protamine reaction
Massive perioperative hemorrhage
Massive PE
Obstetrical catastrophes (e.g., LAST, AFE, and cardiac arrest in the parturient)
Prevention
Wean from CPB with all necessary inotropic and mechanical myocardial support
Verify protamine reversal and obtain good hemostasis prior to chest closure
Perform a post-CPB TEE examination to evaluate ventricular and valvular function
Manifestations
Signs of global or regional myocardial dysfunction
Visible cardiac distention and poor myocardial contractility
Systemic hypotension with increased filling pressures
Wall motion abnormalities on TEE (global or regional)
Abnormalities of ECG morphology or rhythm
ST elevation, often on the inferior leads II, III, AVF
Heart block
Ventricular arrhythmias (VT, VF)
Asystole
Severe hemorrhage
EEG activity may slow or become quiescent
Cardiac arrest
Management
Alert cardiac surgeon, perfusionist, and nursing team of the situation
Emergent CPB usually takes some time to organize for heparinization, CPB circuit preparation, and placement of arterial and venous cannulae (not in the context of ongoing cardiac surgery)
Resuscitate the patient
Check that the patient is being oxygenated (deliver 100% O 2 ) and ventilated and that infusions of vasopressors are running; adjust ventilation and infusion rates as necessary
Administer boluses of vasopressors IV as necessary (see Event 9, Hypotension )
Phenylephrine IV, 100 to 200 μg, and escalate as necessary
Ephedrine IV, 10 to 20 mg
Epinephrine IV, 10 to 50 μg, and escalate as necessary
Administer IV fluids
Crystalloid bolus IV, 500 mL, and additional boluses as needed
Colloid bolus IV
Hetastarch 500 mL
5% albumin 250 to 500 mL
RBCs—if massive hemorrhage, inform blood bank of the ongoing need for blood products; initiate your facility’s MTP
Once the decision has been made to go on CPB stat, ANTICOAGULATE THE PATIENT
Administer heparin through a central line or surgeons may choose to administer heparin intra-atrially
Heparin dose will depend on the current level of anticoagulation and whether the patient has received protamine.
Aim for ACT > 400 seconds
Initial heparin dose should be at least 300 units/kg
Perfusionist should immediately prime the oxygenator and CPB pump circuit
If there is any question about the circulation of heparin, have an additional 15,000 units of heparin added to the pump prime
Volume can be delivered to the patient via arterial cannula once it is in place
Cardiac surgeon should cannulate the arterial system (aorta or femoral artery) first, then the venous system (right atrium or femoral vein)
If there is massive hemorrhage, the cardiotomy suction cannulae can be used as the source of venous drainage (MUST heparinize before doing this)
Anesthesiologist should consider administering additional anesthetic agents if the case is prolonged once the patient is stable
Check an ABG; correct acidosis if present
Complications
Difficulty in separation from CPB
Myocardial ischemia or infarction
Coagulopathy
Stroke
Arrhythmias
Cardiac arrest
Death