How to manage Disseminated Intravascular Coagulation (DIC) in a patient with acute liver failure and substernal hematoma after off-pump Coronary Artery Bypass Grafting (CABG)?

Management of DIC in Post-Off-Pump CABG with Acute Liver Failure and Substernal Hematoma

This critically ill patient requires immediate identification and aggressive treatment of the underlying cause of DIC while simultaneously managing life-threatening bleeding with blood product support, recognizing that the combination of acute liver failure and post-cardiac surgery coagulopathy creates an exceptionally high-risk scenario where therapeutic anticoagulation is contraindicated due to active substernal hematoma. 1, 2

Immediate Diagnostic Priorities

Distinguish DIC from Cirrhotic Coagulopathy Alone

Clinical context is the key to differentiating DIC from rebalanced hemostasis in liver failure. 1

• Rule out inciting events that provoke DIC in liver failure patients: infection/sepsis, ongoing bleeding, shock, acid-base disturbances, or surgical complications 1
• Critically ill patients with cirrhosis develop DIC at rates of 63% versus 9% in those without liver disease 1
• The substernal hematoma itself may represent both a consequence of coagulopathy and a trigger for consumptive coagulopathy 1

Laboratory Assessment Beyond Standard Coagulation Tests

• Soluble fibrin is more useful than thrombin-antithrombin (TAT) complexes for diagnosing coagulation activation in liver failure because TAT levels are dependent on antithrombin concentration, which is reduced in liver disease 1
• Low Factor VIII activity levels and/or high Factor VIII antigen/activity ratio can help identify DIC in patients with cirrhosis 1
• Markedly elevated D-dimer may indicate portal vein thrombosis as a complicating factor 1
• Serial monitoring is essential as DIC is a dynamically changing scenario 2

Critical Management Algorithm

Step 1: Treat the Underlying Cause (Highest Priority)

The cornerstone of DIC treatment is addressing the underlying condition. 2, 3

• Aggressively manage acute liver failure: ensure adequate fluid resuscitation, maintain mean arterial pressure 50-60 mmHg with vasopressors (epinephrine, norepinephrine, or dopamine—NOT vasopressin), and use continuous renal replacement therapy if needed 1
• Evaluate for urgent liver transplantation as this may be the only definitive treatment if progressive consumptive coagulopathy occurs without an identifiable reversible cause 1
• Rule out and treat infection/sepsis as this is the most common trigger for DIC in liver failure patients 1
• Assess for ongoing surgical bleeding requiring re-exploration, as the substernal hematoma may indicate inadequate hemostasis 1

Step 2: Blood Product Support Strategy

Transfusion should NOT be based on laboratory results alone but reserved for active bleeding or high bleeding risk situations. 2

For Active Bleeding with Substernal Hematoma:

• Fresh frozen plasma (FFP) for prolonged PT/aPTT with active bleeding: FFP offers advantages over factor concentrates in liver disease because it provides global factor replacement 4, 2
• Target dose: Sufficient to achieve hemostasis, recognizing that hypervolemia may complicate management in liver failure 4
• Platelet transfusion if count <50 × 10⁹/L in bleeding patients or those requiring invasive procedures 2
• Fibrinogen concentrate or cryoprecipitate if fibrinogen <1 g/L persists despite FFP replacement 2

Critical Caveat on Prothrombin Complex Concentrates:

AVOID prothrombin complex concentrates (PCCs) in this patient. 5

• PCCs carry risk of thrombosis and DIC, particularly in patients with liver disease 5
• Recent evidence shows PCC therapy in cirrhosis led to DIC in 30% of patients overall and >50% in acute-on-chronic liver failure 1
• Only consider PCCs if FFP transfusion is impossible due to fluid overload AND life-threatening bleeding continues, recognizing they only partially correct the defect 2

Step 3: Anticoagulation Decision (Critical)

Therapeutic anticoagulation with heparin is CONTRAINDICATED in this patient due to active substernal hematoma. 2, 3

When Heparin Would Be Indicated (NOT in this case):

• DIC with predominant thrombosis (arterial/venous thromboembolism, severe purpura fulminans, vascular skin infarction) 2
• Chronic DIC with thrombotic manifestations 3

What IS Appropriate:

• Prophylactic-dose heparin or LMWH once bleeding is controlled and substernal hematoma is stable, as post-CABG patients are at high VTE risk 2
• Monitor clinically for bleeding rather than targeting specific aPTT ratios if prophylactic anticoagulation is initiated 2

Step 4: Avoid Harmful Interventions

Do NOT use antifibrinolytic agents (tranexamic acid) in DIC unless there is a primary hyperfibrinolytic state with severe bleeding. 2

• The risk of thrombotic complications outweighs benefits in consumptive DIC 2
• This patient's DIC is consumptive, not primarily hyperfibrinolytic 1

Recombinant activated protein C is contraindicated given the active bleeding and likely platelet count <30 × 10⁹/L 2

Antithrombin concentrate cannot be recommended absent prospective evidence of benefit in DIC patients not receiving heparin 2

Surgical Considerations for Substernal Hematoma

Off-pump CABG is associated with less bleeding and reduced reoperation for bleeding compared to on-pump CABG, but when bleeding occurs, it requires prompt surgical evaluation. 6

• Assess for need for surgical re-exploration if hematoma is expanding or causing hemodynamic compromise 1
• The combination of liver failure and post-cardiac surgery creates exceptionally high surgical risk (CABG in liver failure has 26% operative mortality overall, 67% in Child C cirrhosis) 1

Monitoring Strategy

Serial clinical and laboratory monitoring is mandatory to assess response to treatment. 2, 3

• Repeat coagulation parameters, platelet count, fibrinogen, and D-dimer every 6-12 hours initially 2
• Monitor for signs of thrombosis (despite bleeding risk, thrombotic complications can occur) 2
• Assess for progression to multi-organ failure requiring escalation to transplant evaluation 1
• Maintain blood glucose <180 mg/dL with continuous insulin infusion to reduce infectious and bleeding complications 1

Prognosis and Transplant Consideration

If progressive consumptive coagulopathy continues without identifiable reversible cause, the patient may be in terminal liver failure where DIC represents the end-stage, and urgent liver transplantation is the only treatment. 1

• Combined CABG and liver transplantation has been reported with 80% survival at 35 months in highly selected patients 1
• However, the presence of acute DIC with active bleeding substantially increases perioperative risk 1