Introduction
Disorders that affect blood clotting or hemostasis are termed coagulation disorders. These disorders could be caused by a lack of clotting factors, resulting in delayed clotting, or an increase in some of the clotting factors, which causes the formation of blood clots more frequently. Both can be dangerous and require attention. Surgical procedures are contraindicated unless these bleeding disorders are managed appropriately.
What Are Coagulation Disorders?
Coagulation disorders are also called blood clotting disorders or thrombophilias. Blood clotting disorders prevent the normal clotting of blood in a wound (hemostasis). Clots are a normal part of wound healing and help to prevent bleeding. Clotting disorders can be inherited genetically or acquired at one age. It can cause different problems in the body. The signs and symptoms can vary depending on the part of the body in which it is found. Anemia is the most common symptom seen. Increased bleeding time and blood loss could be other signs.
Coagulation disorders are classified as inherited, acquired, and those due to other reasons.
They are manifested as arterial or venous thrombosis (a condition where a blood clot is formed in a vein). Venous thrombosis is more common than arterial thrombosis. All coagulation disorders may not show the presence of athrombosis. As a result, diagnosing a coagulation disorder might be challenging. Studies show that deficiencies in proteins C, S, and antithrombin III can be the cause of acquired coagulation disorders. 15 percent of venous thrombosis cases are found to be acquired. On the other hand, the most common cause of inherited coagulation disorders is the presence of factor V Leiden mutation (FVL, a mutation in one of the clotting factors).
How Are Coagulation Disorders Managed for Surgery?
Patients should be diagnosed with any blood disorders before they are posted for any surgical procedures requiring any type of anesthesia, ranging from local anesthesia to regional or general anesthesia. Coagulation disorders that are inherited through genes are termed inherited coagulation disorders.
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Hemophilia: Hemophilia causes an increased bleeding time, as the clotting factors are absent. It is a sex-linked recessive disorder, where males are usually affected while females remain as carriers. Hemophilia A is due to the deficiency in factor VIII coagulant protein. On the other hand, hemophilia B is due to the deficiency in factor IX coagulant protein.
Management for Surgery: Hemophilia patients have to undergo therapeutic strategies to replace the deficient coagulation factors before a surgical procedure to prevent complications. For the first five to seven days following major surgery, a target concentration of 100 percent factor VIII has to be maintained. However, for a minor surgery, after the first day, concentrations of fifty percent may be sufficient.
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Von Willebrand's Disease: Von Willebrand factor helps in platelet adhesion and acts as a carrier for factor VIII coagulant protein. The abnormal production of Von Willebrand factor causes Von Willebrand's disease. The symptoms of the condition include mucosal bleeding, easy bruising, and increased bleeding time. This is the most commonly seen inherited coagulation disorder and is an autosomal dominant trait. Studies show that it is present in about 20 percent of women with menorrhagia (prolonged bleeding during menstruation).
Management for Surgery: The use of blood components can help to control hemorrhage in a majority of cases. An antifibrinolytic agent called tranexamic acid helps to manage small bleeds like menorrhagia or epistaxis (bleeding from the nose) during the postoperative period. Providing a dose of DDAVP (Desmopressin, a synthetic vasopressor) ninety minutes before a surgical procedure helps to increase the levels of von Willebrand factor and factor VIII coagulant proteins levels efficiently in most people with the deficiency.
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Disseminated Intravascular Coagulation (DIC): This rare condition can be due to an infection, malignancy, shock, liver disease, or transplantation. It causes abnormal blood clots in the body. While preparing for any type of anesthesia for surgery, coagulation management is essential.
Management for Surgery: A blood transfusion guided by the signs and symptoms shown would help to manage this condition. In some cases, heparin and platelet support can be helpful, while in some other cases, an antifibrinolytic might be necessary. All these can depend on the cause of coagulation in the circulation.
Some coagulation disorders are acquired and occur as a result of dysfunction of some systems in the body. This is called acquired coagulation disorder.
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Renal Disease: There is a decrease in erythropoietin production in case of diseases affecting the kidney. Erythropoietin is produced in the kidneys and helps in the formation of red blood cells in the bone marrow. An altered production of erythropoietin causes an elevation of bleeding time.
Management for Surgery: This can be managed by DDAVP administration. During the pre-operative period, it can be rectified to an extent by providing iron supplements.
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Liver Disease: A majority of coagulation factors are produced by the liver. Hence, a defective functioning of the liver can cause many bleeding disorders. Management of the condition depends on providing the coagulation factor necessary, either by transfusion or through supplements.
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Heparin-induced Thrombocytopenia (HIT): This condition can occur as a serious complication of taking a blood thinner called heparin. In HIT, the immune system causes platelets to form clots even though there is heparin. This causes an increase in the bleeding time. This can cause an increase in post-operative complications and mortality rates.
Management for Surgery: Withdrawal of Heparin and anticoagulation using heparinoids (drugs that help to prevent clotting of blood), like Danaparoid or Lepirudin, as parenteral therapy should be done. Patients who take blood thinners are advised to stop it temporarily after consulting a healthcare professional before surgery to prevent complications.
How Are Patients Under Anticoagulants Managed in the Perioperative Period?
People who take anticoagulants to prevent stroke or other complications of various cardiovascular diseases are increasing rapidly in the modern world. Minor surgical procedures, like a dental extraction or an endoscopy, might be harmless if the anticoagulant is stopped for a few days after consulting a healthcare professional.
However, two groups of people would require an intravenous supply of unfractionated heparin during the perioperative period. This is mainly to prevent therapeutic anticoagulation without post-operative bleeding. This includes people with mechanical cardiac valve prostheses (mechanical devices that help the proper functioning of the heart) and those with a history of acute venous thromboembolism (formation of blood clots in the vein) within four weeks of the planned surgical procedure. In these cases, heparin must be stopped six hours before the procedure and reintroduced twelve hours after the surgery. It is best to avoid epidural anesthesia in these patients.
Even normal patients without any history of thrombophilia markers have an increased risk of developing venous thromboembolism - immobility after the surgery and the inflammatory response following the surgical procedure. Hence, the patient should be well informed about leg exercises and the need for early immobilization. They should be advised of appropriate anti-embolism hosiery, like compression stockings. Anticoagulant prophylaxis should be advised in high-risk and moderate-risk patients appropriately.
Conclusion
Blood and coagulation disorders are currently diagnosed more frequently than before. They may have many anticoagulant and antiplatelet medications. Hence, they should be monitored properly and appropriately managed before providing anesthesia for any surgical procedures. Choosing the appropriate route of anesthesia, proper anticoagulant bridging, and postoperative care can help prevent further complications after surgery in these patients.
