Postoperative Hemorrhage

Matthew Tichauer

Martha DiMilla

D. Dante Yeh

I. INTRODUCTION

Perioperative bleeding, a risk with any operation, presents a challenge for both the surgeon and anesthesiologist. While mortality associated with most surgical procedures typically ranges between 0.1% and 8%, depending upon the nature of the operation, postoperative bleeding significantly affects mortality risk with estimates as high as 20%. In addition to the associated increase in morbidity and mortality, postoperative bleeding, if not identified and managed expediently, may lead to unintended intensive care unit admission and prolonged hospital stays.

II. RISK FACTORS FOR PERIOPERATIVE BLEEDING

A. Surgical and Patient-Based Risk Factors

Among all sources of perioperative bleeding, failure to establish surgical hemostasis intraoperatively is the most common cause. Although this is never the intention of the surgeon, it underscores the importance of due diligence and careful attention to detail in the planning and execution of all surgical procedures (Table 21.1). While most operations carry the risk of bleeding, certain factors increase the likelihood of severe bleeding.

1. Surgical procedures such as trauma, cardiac/cardiovascular, and cancer surgery

2. Massive blood loss resulting in disorders of coagulation (e.g., dilutional coagulopathy, factor deficiencies, platelet loss, or consumption)

3. Drug-induced coagulation disorders (e.g., warfarin)

4. Liver disease

5. Inherited disorders of coagulation (e.g., hemophilias and von Willebrand disease)

TABLE 21.1 Causes of Intraoperative and Postoperative Hemorrhage

Intraoperative	Early Postoperative (Days 0-2)	Delayed Postoperative (Days 2-7)
Structural/technical defects	Structural/technical defects	Thrombocytopenia
Disseminated intravascular coagulation Heparin overdose	Thrombocytopenia Inherited or acquired platelet disorders	Acquired platelet disorders Vitamin K deficiency
Hyperfibrinolysis Antibodies to factor V following use of bovine thrombin in fibrin	Mild to moderate inherited coagulation disorder	Multiorgan failure
Marietta M, Facchini L, Pedrazzi P, et al. Pathophysiology of bleeding in surgery. Transplant Proc 2006;38(3):812-814.

6. Hypothermia

7. Acidemia

III. PATHOPHYSIOLOGY OF HEMOSTASIS AND ASSESSMENT OF COAGULOPATHY

The vessel wall, platelets, and plasma proteins (coagulation factors), acting in conjunction, form the basis for hemostasis.

A. Primary hemostasis, occurring within seconds of vessel wall injury, results in the formation of a platelet plug. There are four steps involved in formation of the platelet plug:

Platelet activation → adhesion → degranulation → aggregation

B. Secondary hemostasis involves coagulation factors of the intrinsic and extrinsic cascade, resulting in the formation of fibrin. Factor VIIa represents the convergence of the intrinsic and extrinsic cascade.

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