As there continues to be an increasing demand for blood products in Hong Kong,1,2 a consensus regarding the management of anemia in patients with gastrointestinal bleeding (GIB) must be established in order to provide a sustainable long-term solution. The Hong Kong Society of Gastroenterology, the Hong Kong IBD Society, the Hong Kong Society of Digestive Endoscopy, and the Hong Kong Red Cross Blood Transfusion Service (BTS) have recently released joint recommendations on the management of anemia in patients with gastrointestinal bleeding.2 With the speed of blood loss, i.e. acute or chronic, as the focus of the analysis, the joint recommendations provide standardized clinical practices to manage the two types of GIB.2
Blood transfusion practices are highly prevalent in Hong Kong, owing to the lack of local standardized protocols for transfusion; as well as the growing aging population in the city.1,2 According to a report published by the Hong Kong Red Cross BTS, the demand for red blood cells (RBCs) in 2016 was 34% more than that of 2006, indicating a large growth in the practice of blood transfusion.1 Furthermore, an age-based analysis in the report indicated that the highest amount of blood transfusions was conducted in older-age groups, a subset of the population that has been growing steadily (persons aged 65 years and over comprised 12.9% of the population in 2006 vs. 16.6% in 2016).1,3 After consideration of all the above factors, the joint recommendations aimed to provide sustainable and standardized protocols for the management of anemia resulting from GIB.
GIB can be further classified as acute or chronic, based on the speed of blood loss. Acute GIB is defined as frank bleeding from the gastrointestinal (GI) tract, with or without iron-deficiency; whereas chronic GIB is defined as guaiac-positive stool accompanying iron deficiency.2 As both types differ in etiology, the management strategies of the two must be distinctive as well.2
For acute GIB, it is recommended to consider the hemoglobin threshold prior to administering treatment. Restrictive transfusion strategy is optimal for patients, targeting a hemoglobin threshold of 7 to 8g/dL.2 A restrictive strategy is associated with significantly lower short-term mortality. 2,4,5 In a study by Villanueva et al, the risk for death at 6 weeks was lower in the restrictive transfusion group compared to the liberal transfusion group (HR=0.55; 95% CI: 0.33-0.92; p=0.002).4 These findings were strengthened by a meta-analysis of four randomized controlled trials, which demonstrated similar benefits in a restrictive strategy.5 However, a liberal transfusion strategy may be adopted when patients present with concurrent symptomatic coronary artery disease, targeting a hemoglobin threshold of 9 to 10g/dL.2 Additionally, for patients with acute GIB with borderline low hemoglobin, iron replacement should be considered after establishing hemostasis, rather than transfusion.2
For chronic GIB, a different strategy is recommended. Since chronic GIB presents with iron deficiency, the recommendation is for iron supplementation with oral or intravenous (IV) iron, before consideration of blood transfusion2 Oral iron supplementation remains the first-line preference, due to its low cost, ease of administration and lack of anaphylactic reaction.2 However, in patients with poor compliance, malabsorption, severe anemia or inflammatory bowel disease (IBD), IV iron may be considered as an alternative.2 In fact, IV iron has been vastly improved over the recent years to provide a safe and well-tolerated infusion.2 IV iron options in Hong Kong include iron sucrose and iron isomaltoside, both of which have demonstrated safety and low risk of adverse events.2 Blood transfusion should not be used for chronic GIB unless the patient has severe anemic symptoms that need to be corrected swiftly.2
In conclusion, for the treatment of anemia associated with GIB, the speed of blood loss must be determined, followed by hemostasis and finally treatment with transfusion or iron supplementation.2 For acute GIB, a restrictive transfusion strategy should be adopted as first-line treatment, unless the patients present with concomitant coronary artery disease.2 For chronic GIB, iron replenishing should be prioritized, with oral iron as first-line treatment, and IV iron for patients with non-compliance or IBD.2