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 Table of Contents  
Year : 2021  |  Volume : 6  |  Issue : 1  |  Page : 38-42

A retrospective study of single-unit transfusion in a tertiary care center of Southern India

1 Department of Transfusion Medicine, All India Institute of Medical Sciences, Nagpur, Maharashtra, India
2 Department of Transfusion Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India

Date of Submission28-May-2020
Date of Decision16-Jul-2020
Date of Acceptance15-Sep-2020
Date of Web Publication29-May-2021

Correspondence Address:
Dr. Abhishekh Basavarajegowda
Department of Transfusion Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/GJTM.GJTM_51_20

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Background and Objectives: Single-unit transfusions continue to be a widespread transfusion practice. Single-unit red blood cell (RBC) transfusions were treated with substantial denunciation in the past but recently have been reviewed as to whether it is acceptable or could be acceptable. This study was undertaken to observe the overall profile of the patients receiving the single-unit transfusion and analyze the possible rationale of such transfusion. Methods: This was a retrospective record-based study conducted in multispecialty tertiary level care teaching hospital over a period of 1 year from January to December 2017. Variables included were age, gender, diagnosis, indication for transfusion, pre- and post-hemoglobin, additional modality of treatment received including other blood components and length of hospital stay. Qualitative variables were described as number and percentages, and quantitative variables as number, mean, and standard deviation. Results: During the study, 50,880 blood components were issued out of which, packed RBCs (PRBCs) accounted to 19760. Twenty-four percent (4742 units) of the total blood units were transfused as single unit of PRBC. 52.1% of these single-unit transfusions were carried out by the surgical specialties. Conclusion: Single-unit transfusions are more common in medical specialties probably due to the chronic nature of the diseases. However, even in surgical specialties, especially those striving toward reducing blood usage and the ones operating in more of an elective setting, single-unit transfusions were higher.

Keywords: Single-unit, transfusions, Red blood cells

How to cite this article:
Das S, Basavarajegowda A. A retrospective study of single-unit transfusion in a tertiary care center of Southern India. Glob J Transfus Med 2021;6:38-42

How to cite this URL:
Das S, Basavarajegowda A. A retrospective study of single-unit transfusion in a tertiary care center of Southern India. Glob J Transfus Med [serial online] 2021 [cited 2021 Dec 7];6:38-42. Available from: https://www.gjtmonline.com/text.asp?2021/6/1/38/317175

  Introduction Top

Blood products are limited in supply and allogeneic transfusion is not without risk. Packed red blood cells (PRBC) transfusions are generally used to treat hemorrhage and for improving oxygen delivery to tissues. There is debate in the medical literature either to follow “restrictive” thresholds (transfusion indicated only when hemoglobin level is 7–8 g/dL) or “liberal” thresholds (transfusion indicated at hemoglobin level of 9–10 g/dL). Clinical trials investigating their use have suggested waiting up to lower hemoglobin levels before transfusion is beneficial.[1],[2],[3] Transfusion of red blood cells (RBCs) is supposed to be based on the patient's clinical condition rather than based on hemoglobin levels.[4] A restrictive transfusion policy with strict transfusion triggers and a heedful use of blood products is supposedly the most productive measure in reducing transfusion requirements in view of the dearth and imminent risks of blood products from allogeneic donors. Reducing the volume of blood per transfusion will save a substantial number of RBC units and hence thereby reducing the exposure to allogeneic blood products.[5]

The use of single-unit transfusions continues to be a cornerstone of transfusion practice. Single-unit RBC transfusions were treated with substantial denunciation in the past. It was believed that “RBC transfusions were useless if the transfusion requirements could be satisfied by infusion of one RBC unit and that patients were no more in need of the transfusion than their donors.” The use of single-unit transfusions was, hence branded as “wasteful” and was considered unjustifiable in view of the risks associated. Despite not having much of the evidence to support, this transfusion practice continues to be in prevalence.[5] A retrospective study showed that transfusion of 1 unit instead of 2 units resulted in a 25% reduction of PRBC units transfused without progression of symptomatic anemia or side effects.[5] The data on the benefit or risk of a single-unit transfusion strategy are sparse and bulk of the evidence is derived from studies exploring perioperative single-unit RBC transfusions in surgical and obstetric populations.[5],[6]

Only sparse studies are available in the literature on this topic.

  Aim Top

The aim of the study was to estimate the proportions of single-unit transfusions in our center and observe the overall profile of the patients receiving them. The study will guide both transfusion medicine specialist and physicians to circumspect on the single-unit transfusion for the patient and ensure more appropriate usage of this sparse resource.

  Methodology Top


This study was a retrospective audit in a tertiary care 2200 bedded hospital of South India. This audit reviewed the medical records of patients who received single-unit transfusion between January 2017 and December 2017. Eligible patients were identified after going through the issue records which is maintained by the Department of Transfusion Medicine. All the hospitalized patients who had received a single-unit of PRBC transfusions during a single hospital stay were included in the study. All the transfusion in the pediatric and neonatal set up and the patients with insufficient data regarding the justification for the single-unit transfusion were excluded from the data analysis. Data were collected from the identified patient records using a designated form.


The study was approved by the Institute Ethics Committee vide letter no. JIP/IEC/2017/0112 with waiver of consent as the data collection was record based in de-identified manner.

Data collection

Initial data regarding the patients who had received a single-unit transfusion in the 2017 were collected from the blood bank information system and the crossmatch forms. The detailed profile and clinical data of the patient were collected from the patient medical record file as per a predesigned pro forma. The variables included age, gender, diagnosis, blood group, indication for transfusion, pre- and post-hemoglobin, additional modality of treatment received including other blood components and length of hospital stay. All the data were tabulated into Microsoft Excel sheet for the analysis. The unit of transfusion is for the single admission. That means if the patient receives transfusion on two different admissions, they are taken as different units.

Statistical analysis

The data regarding the single-unit transfusion were collected from the patient's case sheet and the transfusion records from January to December 2017. Qualitative variables were described as number and percentages, and quantitative variables as number, mean, and standard deviation.

  Results Top

In the year 2017, 50,880 blood components were issued out of which, PRBCs accounted to 19,760. Out of them 24% (4742 units) single-unit of PRBCs were transfused. The median patient age was 45 (18–95) years and females accounted for 56% among them. In our study, 52.1% single-unit transfusions were carried out by the surgical specialties, 38.1% by the medical specialties and 8.2% were in the emergency department. [Table 1] shows the distribution of single-units used in comparison to the total number of transfusion from the particular specialty.
Table 1: Department-wise single unit usage verses total use of blood components

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The surgical departments had used 52.1% (n = 2470) of single-unit transfusion at pre-, intra-, and postoperative stage. [Table 2] shows various reasons of utilization single unit by the surgical department. Intraoperative single-unit transfusion was the most common indication. Among the intraoperative group, 10% (n = 126 patients) required additional blood component transfusion which included FFP, platelets, respectively.

The medical specialty departments had used 34.1% (n = 1617) of single-unit transfusion. The usage by various medical departments is shown in [Table 3].
Table 2: Surgical departments – usage of single unit

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Table 3: Medical departments- usage of single unit

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  Discussion Top

Our retrospective audit demonstrates that 24% of total PRBC transfusion accounted for single-unit transfusion. Single-unit RBC transfusion means “prescribing only one unit of blood at a time,” followed by an assessment of the patient.[7] The administration of this single unit of blood may be “incidental” (one among the series of transfusions), or “accidental” (when the original intent is to give more but was curtailed due to death) or an unexpected improvement in patient's condition. The last two scenarios are inevitable and therefore acceptable. The first category is supposedly the most common and also debatable with regard to their usage. Sometimes, it demonstrates “an unusual skill in the use of transfusion as a therapeutic tool” whereas otherwise it is thought to be an act of thoughtlessness or incompetence. Hence, many administrators and accreditation agencies keep the scores of these transfusions. Each unit of blood transfused carries risks.

In the current study, the total no of single-unit transfusion is the least as compared to the other published literature.[5],[6],[8] This is possibly due to improved practices over the period as evidence is available for the restriction use of PRBC in a stable patient.[2],[9]

The percentage of single units was very high in departments of immunology, pulmonology, cardiology, and dermatology probably because in these departments, transfusion is relatively uncommon and most of the emergency circumstances which require transfusion massively the patients would be shifted to emergency or acute care and only after stabilization they come back to these departments.

Few departments such as surgical gastroenterology, neurosurgery, and plastic surgery have more than half of their transfusion as single-units.[10],[11],[12],[13],[14] This could actually reflect a good trend as these departments are reducing the usage of blood during perioperative phase due to utilization of better technologies and equipment for surgery as well as fine tuning and improvisation of skills.[13] The practice of single-unit transfusion actually lessens the risks accompanying transfusion by reducing the total number of RBC units transfused. It aids by decreasing the pressure on the blood supply. It also has reducing effects on the healthcare costs by adaptation of more judgmental transfusion practice.

In departments such as oncology (both surgical and medical), hematology, the requirements of blood products are usually huge and most unlikely to receive single units given the nature of the disease itself. In departments like medicine, usually patients are on regular follow-up mostly for chronic diseases. Since this study included number of transfusions in a single admission, it is possible that these patients would have received one unit each in each admission in the course of their regular follow-up. In few instances, it is used to bridge the gap and buy time to arrive at diagnosis or the specific therapy takes over (therapeutic foundation). One unit of red cells is known to raise the hemoglobin concentration of an average sized adult (70 kg) by approximately 1 g. In numerous instances, this alone would be adequate to improve symptoms. A good number of studies have shown that single transfusions are actually safe and in effect reduce morbidity and mortality associated with transfusion.[8],[11]

With regard to surgery one-third of the single-unit transfusion were utilized for correction of Hb preoperatively. Concerns still remain with regard to transfusion of single unit to pass a magic line at 10 g/dl, elective transfusion for a procedure, hasten convalescence which are not supported by scientific evidence and could be detrimental as well as leads to wastage of precious gift of mankind.[15] Like for like replacement by transfusion intraoperatively when blood loss was more than the allowable limit seems somewhat justified.

Obstetrics and gynecology being a combination of medical and surgical modalities it is tough to comment. However, most of the single units were utilized to correct the Hb before taking up for surgery or for patients with antenatal anemia or dysmenorrhea wherein the patients were managed conservatively.

Commonly held beliefs like a “single RBC transfusion is a wasted transfusion,” 'if the patient only needs one unit, then s/he does not need any' have been revisited and addressed. Australian National Blood Authorities have come up with guidelines which recommend usage of “single-unit transfusion to stable, normovolaemic adult patients, in an inpatient setting, who do not have clinically significant bleeding.”[16] If one unit of PRBC transfusion has achieved the required outcome, for example, clinical improvement in signs and symptoms of anemia usually assessed by fatigue, general well-being, pallor, etc., further transfusion of blood units will only lead to an increase the risks associated with transfusion.[17] Studies have shown that single-unit transfusions had no increased risk of bleeding or lead to increased consumption of platelets in these patients when compared to those receiving more than 1 unit. It leads to saving of up to 30% of blood units and its associated risks. All these have resulted in many hospitals having a single-unit transfusion ordering policy.

Considering the above, transfusion of a single-unit would be a boon to the patient when it can reduce his chances of having an adverse event, reduce his hospital visit and giving a relief from his symptoms. However, routinely giving it as a ritual when it could have been avoided would be a bane given the apprehensions and reactions associated with it and burden of arranging donation when the onus lies on patient bystanders or the treating physicians himself.

The strength of this study is that ours is a multi-specialty hospital with huge volume of patients. Hence, the data would be more comprehensive and inclusive which was missing in most of the previous studies either because it was a standalone blood bank or in hospitals who did not have all the specialties. We also have excluded pediatric patients as it does not make much sense to define single-unit in them. The drawback of the study was that it was performed based on records retrospectively and hence few of the data may be missed or not available.

  Conclusion Top

Single-unit transfusions are more common in medical specialties probably due to the chronic nature of the diseases. In surgical specialties, single-unit transfusions were more common in departments wherein the surgery is more of an elective nature. Studies may be taken up prospectively to look into whether the single-unit transfusion has positive impact on the inventory without clinically compromising the patient's health. Large data analysis may also show if there was difference in risk in patients who received single-unit against those who received multiple units.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Hébert PC, Wells G, Blajchman MA, Marshall J, Martin C, Pagliarello G, et al. A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. Transfusion requirements in critical care investigators, Canadian Critical Care Trials Group. N Engl J Med 1999;340:409-17.  Back to cited text no. 1
Goel R, Chappidi MR, Patel EU, Ness PM, Cushing MM, Frank SM, et al. Trends in red blood cell, plasma, and platelet transfusions in the United States, 1993-2014. JAMA 2018;319:825-7.  Back to cited text no. 2
Salpeter SR, Buckley JS, Chatterjee S. Impact of more restrictive blood transfusion strategies on clinical outcomes: A meta-analysis and systematic review. Am J Med 2014;127:124-31000.  Back to cited text no. 3
Carson JL, Guyatt G, Heddle NM, Grossman BJ, Cohn CS, Fung MK, et al. Clinical practice guidelines from the AABB: Red blood cell transfusion thresholds and storage. JAMA 2016;316:2025-35.  Back to cited text no. 4
Berger MD, Gerber B, Arn K, Senn O, Schanz U, Stussi G. Significant reduction of red blood cell transfusion requirements by changing from a double-unit to a single-unit transfusion policy in patients receiving intensive chemotherapy or stem cell transplantation. Haematologica 2012;97:116-22.  Back to cited text no. 5
Naylor JM, Adie S, Fransen M, Dietsch S, Harris I. Endorsing single-unit transfusion combined with a restrictive haemoglobin transfusion threshold after knee arthroplasty. Qual Saf Health Care 2010;19:239-43.  Back to cited text no. 6
ISBT: 6. Single-Unit Transfusion. Available from: https://www.isbtweb.org/working-parties/clinical-transfusion/6-single-unit-transfusion/. [Last accessed on 2019 Nov 10].  Back to cited text no. 7
Gupte SC, Shaw A. Evaluation of single unit red cell transfusions given to adults during surgery. Asian J Transfus Sci 2007;1:12-5.  Back to cited text no. 8
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Crawford-Sykes A, Ehikhametalor K, Tennant I, Scarlett M, Augier R, Williamson L, et al. Blood use in neurosurgical cases at the university hospital of the west indies. West Indian Med J 2014;63:54-8.  Back to cited text no. 10
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Guidance for Australian Health P. Single-Unit Transfusion Guide; 2014. Available from: https://www.blood.gov.au. [Last accessed on 2019 Nov 10].  Back to cited text no. 16
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  [Table 1], [Table 2], [Table 3]


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