Anemia, characterized by a reduction in hemoglobin concentration or red blood cell count, presents unique challenges in the context of anesthesia. It is associated with decreased oxygen-carrying capacity and can lead to inadequate tissue oxygenation, particularly during surgical procedures. Anesthetic management of patients with anemia requires a multidisciplinary approach, encompassing preoperative optimization, intraoperative monitoring, and postoperative care.
Anemia is categorized into several types, including iron-deficiency anemia, anemia of chronic disease, hemolytic anemia, and anemia due to acute blood loss. Its severity is classified based on hemoglobin levels: mild, moderate, and severe—and the type and severity of anemia influence anesthesia considerations and perioperative risks.
Surgical patients with anemia face heightened risks of perioperative morbidity and mortality. Reduced oxygen delivery can lead to organ dysfunction, while compensatory mechanisms, such as increased cardiac output, can strain the cardiovascular system. Consequently, optimizing the patient’s condition prior to surgery is crucial 1.
The preoperative phase is critical for identifying and managing anemia. A thorough evaluation should identify symptoms like fatigue, pallor, or dyspnea, and review underlying conditions contributing to anemia. Laboratory investigations include a complete blood count (CBC), iron studies, vitamin B12 and folate levels, and renal function tests. These assessments help determine the cause and severity of anemia. Finally, an assessment of the patient’s overall health and the surgical procedure’s anticipated blood loss guide the development of a patient-tailored anesthetic plan.
For elective surgeries, preoperative optimization of hemoglobin levels is recommended. Iron supplementation (oral or intravenous), erythropoiesis-stimulating agents, or vitamin supplementation can improve red blood cell production. In severe cases, preoperative blood transfusions may be necessary, though they carry risks such as transfusion reactions or infections 1.
Anesthesia for patients with anemia focuses on maintaining adequate oxygenation and minimizing blood loss. Both general and regional anesthesia can be safely used, but regional anesthesia may reduce the need for systemic oxygen consumption. Healthcare providers should consider the patient’s condition and surgical requirements. Additionally, continuous monitoring of oxygen saturation, heart rate, blood pressure, and end-tidal CO₂ provide insights into tissue oxygenation. This can be performed through advanced monitoring techniques such as arterial blood gas analysis and mixed venous oxygen saturation. Blood conservation strategies like acute normovolemic hemodilution, controlled hypotension, and the use of antifibrinolytics (e.g., tranexamic acid) can help to minimize intraoperative blood loss 2,3.
The postoperative period is critical for monitoring and addressing complications. Patients with anemia are at increased risk for delayed wound healing, infections, and cardiovascular events. Pain management strategies that minimize respiratory depression and oxygen desaturation are preferred. Follow-up care should include monitoring hemoglobin levels and addressing any ongoing causes of anemia 4.
Anemia significantly influences anesthetic management, requiring a tailored, patient-specific approach. Preoperative optimization, intraoperative vigilance, and meticulous postoperative care are essential to minimize risks and improve outcomes.
References
1. Hans, G. & Jones, N. Preoperative anaemia. Continuing Education in Anaesthesia Critical Care & Pain 13, 71–74 (2013).
2. Warner, M. A. et al. Perioperative Anemia: Prevention, Diagnosis, and Management Throughout the Spectrum of Perioperative Care. Anesthesia & Analgesia 130, 1364 (2020). DOI: 10.1213/ANE.0000000000004727
3. Shander, A., Lobel, G. P. & Javidroozi, M. Anesthesia for Patients with Anemia. Anesthesiol Clin 34, 711–730 (2016). DOI: 10.1016/j.anclin.2016.06.007
4. Muñoz, M., Franchini, M. & Liumbruno, G. M. The post-operative management of anaemia: more efforts are needed. Blood Transfus 16, 324–325 (2018). DOI: 10.2450/2018.0036-18
