Anemia is a condition that results in low red blood cell count and hemoglobin deficiency, decreasing the blood’s capacity to carry oxygen [1]. The World Health Organization specifies that hemoglobin concentrations of less than 12.0g/dl in non-pregnant women and 13.0g/dl in men could be considered anemic [2]. There are a number of potentially serious consequences of anemia, including increased cardiac output, which can lead to damage to the heart’s muscular tissue [3]. Perioperative anemia is not uncommon and can make surgery and recovery significantly more complicated. Furthermore, anemia in surgical patients is associated with higher morbidity and mortality rates [4].
In order to improve the survival and recovery outcomes for anemic surgical patients, the condition must first be diagnosed and treated appropriately. Unfortunately, perioperative anemia often does not receive the attention it warrants until hemoglobin levels become low enough for blood transfusion [5]. A study by Beattie et al. found that transfusion rates were three times higher for anemic patients than their non-anemic counterparts. [2]. When transfusions are required, the risk of complications such as ischemic stroke and myocardial infarction rises significantly, and transfusions are associated with higher morbidity rates among surgical patients [6].
As anemia has gained attention in the medical community, a number of recommendations and strategies for preventing morbidities associated with anemia in surgical patients have been released. In 2005, an interdisciplinary panel of medical professionals advised that elective surgery patients have their hemoglobin levels tested at least thirty days before surgery and that unexplained anemia should always be considered as an effect of a condition that requires pre-surgical attention [7]. The American Society of Anesthesiology advises that the necessity for blood transfusion is usually indicated at a hemoglobin level of <6g/dl, but that ischemia, bleeding, and other risks should be weighed alongside it [6]. More recently, researchers created an automated system for iron-deficiency anemia screening, which they found to improve diagnosis over clinical procedures [4].
Concerns regarding morbidity rates for anemic patients extend to all members of the surgical team, including anesthesia providers. The anesthesia provider should review vital signs and patient data and evaluate whether red blood cell transfusion is worth the risk to the patient. Because anemia is associated with poorer outcomes, care providers must carefully weigh the decision to administer a transfusion [1]. Several medical associations have issued guidelines for evaluating the necessity of transfusion. These guidelines include considerations of hemoglobin levels as well as various health factors. Current trends indicate that physicians’ ability to identify and treat anemia is developing rapidly, improving outcomes for surgical patients with anemia.
References
[1] Klick, John C., and Edwin G. Avery. “Anesthetic Considerations for the Patient With Anemia and Coagulation Disorders.” Anesthesiology, edited by David E. Longnecker et al, McGraw-Hill, 2012, pp. 196-216.
[2] Beattie, Scott W., et al. “Risk Associated With Preoperative Anemia in Noncardiac Surgery: A Single-Center Cohort Study.” Anesthesiology, vol. 110, 2009, doi: 10.1097/ALN.0b013e318 19878d3.
[3] “Anemia Compensation.” Open Anesthesia, 26 Feb., https://www.openanesthesia.org/anemia _compensation/.
[4] Okocha, Obianuju, et al. “An Effective and Efficient Testing Protocol for Diagnosing Iron-Deficiency Anemia Preoperatively.” Anesthesiology, vol. 133, 2020, 109-118, doi: 10.1097/ALN.0000000000003263.
[5] Warner, Matthew A., et al. “Perioperative Anemia: Prevention, Diagnosis, and Management Throughout the Spectrum of Perioperative Care.” Anesthesia & Analgesia, vol. 130, no. 5, 2020, 1364-1380, doi: 10.1213/ANE.0000000000004727.
[6] Shander, Aryeh et al., “Anesthesia for Patients With Anemia.” Anesthesiology Clinics, vol. 34, no. 4, 2016, 711-730, doi: 10.1016/j.anclin.2016.06.007.
[7] Goodnough, Laurence T., et al. “Detection, Evaluation, and Management of Anemia in the Elective Surgical Patient.” Anesthesia & Analgesia, vol. 101, no. 6, 2005, 1858-1861, doi: 10.1213/01.ANE.0000184124.29397.EB.