Association between preoperative anemia, transfusion, and outcomes in children undergoing noncardiac surgery
Myron Yaster MD, Lynne G. Maxwell MD, James A. DiNardo MD, and Susan M. Goobie MD, FRCPC
I know this is going to be hard for most of you to believe: Until the early 1990s, ALL children undergoing anesthesia and surgery routinely required preoperative hemoglobin and urinalysis screening before surgery. Indeed, we actually cancelled cases if this information was not available. A classic paper by Roy et al.[1] and an accompanying editorial by the late Dr. David Steward [2] challenged the need for routine preoperative hemoglobin testing in ALL children and essentially changed practice. Roy et al. found that less than 1% of patients had preoperative anemia and almost all of them could be identified by history and physical examination. Furthermore, in anemic patients who subsequently underwent surgery there were no untoward effects related to the anemia. Largely as a consequence of their findings and subsequent editorial comments, routine preoperative hemoglobin testing is no longer required or performed in the U.S except in patients undergoing high risk surgical procedures or in patients with significant co-morbidities.
In today’s PAAD, we discuss a study that raises the possibility that this practice should be re-evaluated. McCormack et al.[3] found that in children undergoing non-cardiac surgery “anemia, transfusion, and the combination of both increased 30-day mortality and the incidence of postoperative complications”. Obviously, a definitive diagnosis of anemia can only be made with preoperative testing. Do the findings of this study compel us to perform preoperative testing for anemia in all pediatric patients? Are the results of today’s article applicable to ALL patients? As you will see, I don’t think so, but I’ve asked 2 of the authors of today’s article, Drs DiNardo and Goobie, who are also on the PAAD’s executive council, to assist Lynne and me in today’s PAAD review. Myron Yaster MD
Original article
McCormack G, Faraoni D, DiNardo JA, Goobie SM. Association between preoperative anaemia, transfusion, and outcomes in children undergoing noncardiac surgery. Br J Anaesth. 2025 Aug;135(2):375-381. doi: 10.1016/j.bja.2025.04.050. Epub 2025 Jun 10. PMID: 40500601.
“Studies in adult patients have established a clear independent relationship between preoperative anemia and perioperative mortality.[5] More recently, a similar independent association has been identified in pediatric patients.[6, 7] Given that both RBC transfusion and anemia are associated with increased morbidity and mortality in both pediatric and adult patients, patient blood management (PBM) programs have been developed to identify and manage preoperative anemia, optimize blood conservation strategies perioperatively, avoid unnecessary blood transfusion, decrease postoperative anemia, and hopefully improve patient outcomes.
The objective of this study was to evaluate how the incidence of preoperative anemia and transfusion has changed over the last 11 yr, and to reassess the association between anemia, transfusion, and postoperative outcomes.”[3] The study was not designed to determine the incidence of anemia in the overall pediatric patient population undergoing non-cardiac surgery. In fact, children without a recorded preoperative HCT (n=705,403), who were <1 yr old n=69,652), who had a preoperative RBC transfusion (n=13,718), or with congenital heart disease (n=85, 416) were excluded from the analysis. The study cohort included 429,310 children 1-18 yr of age who had a preoperative hematocrit recorded between 2012 and 2023 in the American College of Surgeons National Surgical Quality Improvement Program pediatric databases. Patients were included in four groups: patients without anemia who did not receive a transfusion, patients without anemia who did receive a transfusion, patients with anemia who did not receive a transfusion, and patients with anemia who did receive a transfusion. The outcomes were 30-day mortality and postoperative complications.”[3]
The incidence of preoperative anemia was 25.7% (n=110,341), and the overall transfusion rate was 10.4% (n=44,808). Between 2012 and 2023, the incidences of preoperative anemia and transfusion remained stable. The incidence of 30-day mortality increased significantly between children without anemia who did not receive a transfusion (0.08%), without anemia who did receive a transfusion (0.30%), with anemia who did not receive a transfusion (0.27%), or with anemia who did receive a transfusion (1.11%). The highest incidence of complications was found in children with anemia exposed to perioperative transfusion.[3] The authors concluded that anemia and transfusion are independently associated with increased 30-day mortality and postoperative complications. The combination of anemia and transfusion was associated with increased 30-day mortality and postoperative complications.[3]
While we (LM, MY) do not dispute the findings of this study, the 25% incidence of anemia gives us pause. We think the overall incidence in the general pediatric surgical population is much closer to the 1% reported in the Roy et al. paper. SG however points out that according to the World Health Organization the prevalence of anemia in children in industrialized countries ranges between 5-20% for the ages 6 months to 5 years with most of those anemias likely to be mild.[6] It is likely that during the study time period, millions of pediatric patients underwent surgery and anesthesia and it is likely that only a small fraction had a determination of preoperative hematocrit. Why? What was different about these patients? And did the frequency of preoperative hematocrit testing change over the time period of the study? Because the data in this study comes from the NSQIP database we don’t know the underlying conditions or physical examination that may have triggered the laboratory test.
An important finding of this paper is that blood transfusion not benign and underscores the need for implementing a patient blood management program (PBM) in your practice. We’ve discussed PBM in several recent PAADs (July 3, 2025: https://ronlitman.substack.com/publish/posts/detail/165482611?referrer=%2Fpublis,h%2Fposts%2Fpublished%3Fsearch%3Dblood and July 7, 2025 https://ronlitman.substack.com/p/pediatric-patient-blood-management-54d ). As a quick review, essential components of PBM consists of 1) screening for, diagnosing, and appropriately treating preoperative anemia; (2) minimizing surgical and procedural blood loss; and (3) managing coagulopathic bleeding.
Thus, even though diagnosing and treating preoperative anemia is an essential element of PBM, we agree with the conclusion of Roy et al. that routine hemoglobin testing in ALL pediatric patients coming for surgery is not indicated and is not cost effective. We believe hemoglobin testing should be reserved for specific patients, based on history, physical examination and the nature of the proposed surgery. What do you think? Do you/your institution routinely obtain preoperative hemoglobin (or other laboratory tests) in non cardiac surgical patients? Send your thoughts and comments to Myron (myasterster@gmail.com) and he will post in a Friday Reader Response.
References
1. Roy WL, Lerman J, McIntyre BG: Preoperative hemoglobin values in minor paediatric surgery. CanJAnaesth 1990, 37(4 Pt 2):S7.
2. Steward DJ: Screening tests before surgery in children [editorial; comment]. CanJAnaesth 1991, 38(6):693–695.
3. McCormack G, Faraoni D, DiNardo JA, Goobie SM: Association between preoperative anaemia, transfusion, and outcomes in children undergoing noncardiac surgery. British journal of anaesthesia 2025, 135(2):375–381.
4. https://www.who.int/data/gho/data/indicators/indicator-details/GHO/prevalence-of-anaemia-in-children-under-5-years-(-)
5. Fowler AJ, Ahmad T, Phull MK, Allard S, Gillies MA, Pearse RM: Meta-analysis of the association between preoperative anaemia and mortality after surgery. British Journal of Surgery 2015, 102(11):1314–1324.
6. Meyer HM, Torborg A, Cronje L, Thomas J, Bhettay A, Diedericks J, Cilliers C, Kluyts H, Mrara B, Kalipa M et al: The association between preoperative anemia and postoperative morbidity in pediatric surgical patients: A secondary analysis of a prospective observational cohort study. Pediatric Anesthesia 2020, 30(7):759–765.
7. Faraoni D, DiNardo JA, Goobie SM: Relationship Between Preoperative Anemia and In-Hospital Mortality in Children Undergoing Noncardiac Surgery. Anesthesia and analgesia 2016, 123(6):1582–1587.