PERIOPERATIVE VOLUME AND BLOOD MANAGEMENT
Key Clinical Questions
What is the best perioperative volume and blood management in orthopedic patients?
Which evidence based strategies prevent orthopedic surgical site infections?
What are the best strategies for perioperative pain management in these patients?
What is the best way to diagnose and manage compartment syndrome?
What is the best way to recognize fat embolism syndrome?
Exposed cancellous bone presents a hemostatic challenge, and consequently, nearly all patients undergoing major orthopedic procedures have some degree of acute blood loss anemia. The estimated blood loss for a total hip replacement is approximately 3.2 units or 4.07 g of hemoglobin, while total knee replacement patients may lose 1 to 1.5 L of blood or 3.85 g of hemoglobin. Blood loss after bilateral or revision joint replacement may be significantly more.
Historically, 10% to 38% of total joint-replacement patients received a postoperative blood transfusion, usually 1 to 2 units for primary arthroplasties and 3 to 4 units for revisions. While blood transfusions may restore oxygen-carrying capacity, replace fluid volume, and increase vigor, they expose patients to risks, including transfusion reactions, transfusion-related lung injury, antigen exposure, higher mortality, disease transmission, immunosuppression, and infection, as well as higher costs and length of stay.
While the most significant risk factor for acute blood loss anemia is the magnitude of the surgical procedure, several other issues must be considered. Patients on chronic anticoagulation are at high risk for development of postoperative anemia. If possible, medications such as warfarin, rivaroxaban, clopidogrel, aspirin, and even nonsteroidal anti-inflammatory drugs should be stopped preoperatively. Therapeutic anticoagulation should ideally be held postoperatively until adequate hemostasis has been assured and the wound has stabilized. Intraoperative bleeding complications are increased by 1.5 times if preoperative aspirin is not stopped, but discontinuation may increase the risk of postoperative cardiac and vascular complications. Thus, cardioprotective doses of aspirin can be continued for most orthopedic surgery patients who are at increased cardiac risk. Transfusion requirements increase by 50% if clopidogrel is continued perioperatively. Bridging anticoagulant therapy with therapeutic low-molecular-weight heparin is associated with a 92% incidence of bleeding complications, 69% occurrence of hematoma, and 15% development of a prosthetic joint infection; the perioperative use of these drugs in therapeutic doses should therefore be undertaken with caution.
Preoperative anemia should be identified, evaluated, and treated. Anemia is present in 21% of elderly patients who are undergoing elective orthopedic surgery. It is also common in patients with thrombocytopenia, chronic disease, and in menstruating females. Total joint-replacement patients with a preoperative hemoglobin <10 g/dL have a 90% risk of needing a transfusion postoperatively. Of note, preoperative autologous donation (PAD) of blood has declined in popularity because of cost, waste from overcollection, and increased transfusions. Current recommendations for the treatment of preoperative anemia include a thorough hematologic workup, correction of vitamin B12 or iron deficiencies, if present, and evaluation for other sources of ongoing blood loss, such as the gastrointestinal tract.
EVALUATION AND MANAGEMENT OF BLOOD LOSS
Intraoperative measures to limit blood loss and resultant anemia include the use of acute normovolemic hemodilution, tourniquets, hypotensive anesthesia, regional anesthesia, avoidance of hypothermia, blood salvage, meticulous hemostasis, topical hemostatic agents, and intravenous antifibrinolytics.