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Blood product transfusions are necessary for critically ill neonates on extracorporeal membrane oxygenation (ECMO). Transfusions are administered in response to unstudied arbitrary thresholds and may be associated with adverse outcomes. The objective of this study was to identify relationships between blood product components and mortality in neonates receiving ECMO support for respiratory indications.A retrospective review of neonates receiving ECMO for respiratory indications from 2002 to 2019 from a single quaternary-referral neonatal intensive care unit (NICU). Demographic and outcome data and transfusion volume (ml/kg/day) were harvested from the medical record, and baseline mortality risk was assessed using NEO-RESCUERS scores. The association between volume of red blood cells (RBC), platelet, plasma transfusion rates (ml/kg/day), and mortality on ECMO were assessed after adjustment for NEO-RESCUERS score. Cox proportional hazards (CPH) competing risk model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for each variable and mortality outcome.Among 248 neonates undergoing ECMO for respiratory failure, overall survival was 93%. RBC, platelet, and plasma volume were highly associated with mortality during ECMO in an unadjusted model. After adjusting for NEO-RESCUERS score, RBC volume was associated with increased mortality risk (HR 1.013, 95% CI 1.004-1.022, p = .0043), but platelet and plasma volume were not associated with mortality.RBC, but not platelet or plasma volume, is associated with mortality in neonates on ECMO. Our findings refute previous studies demonstrating an association between platelet volume and mortality for neonates on ECMO.

Background We sought to compare the quality of washed red blood cells (RBCs) produced using the ACP215 device or manual methods with different combinations of wash and storage solutions. Our aim was to establish manual methods of washing that would permit a shelf life of more than 24 hours. Study design and methods Fourteen-day-old RBCs were pooled, split, and washed in one of five ways: 1) using the ACP215 and stored in SAGM, 2) manually washed and stored in saline, 3) manually washed in saline and stored in SAGM, 4) manually washed in saline-glucose and stored in SAGM, and 5) manually washed and stored in SAGM. Additional units were pooled and split, washed manually or using the ACP215, and irradiated on Day 14. Units were sampled to 14 days after washing and storage at 4 ± 2°C. Results All washed RBCs met specification for volume (200-320 mL) and hemoglobin (Hb) content (>40 g/unit). Removal of plasma proteins was better using manual methods: residual immunoglobulin A in saline-glucose-washed cells 0.033 (0.007-0.058) mg/dL manual versus 0.064 (0.026-0.104) mg/dL ACP215 (median, range). Hb loss was lower in manually washed units (mean, ≤ 2.0g/unit) than in ACP215-washed units (mean, 6.1 g/unit). Disregarding saline-washed and stored cells, hemolysis in all nonirradiated units was less than 0.8% 14 days after washing. As expected, the use of SAGM to store manually washed units improved adenosine triphosphate, glucose, lactate, and pH versus storage in saline. Conclusion The data suggest that the shelf life of manually washed RBCs could be extended to 14 days if stored in SAGM instead of saline.

We sought to compare the quality of washed red blood cells (RBCs) produced using the ACP215 device or manual methods with different combinations of wash and storage solutions. Our aim was to establish manual methods of washing that would permit a shelf life of more than 24 hours.Fourteen-day-old RBCs were pooled, split, and washed in one of five ways: 1) using the ACP215 and stored in SAGM, 2) manually washed and stored in saline, 3) manually washed in saline and stored in SAGM, 4) manually washed in saline-glucose and stored in SAGM, and 5) manually washed and stored in SAGM. Additional units were pooled and split, washed manually or using the ACP215, and irradiated on Day 14. Units were sampled to 14 days after washing and storage at 4 ± 2°C.All washed RBCs met specification for volume (200-320 mL) and hemoglobin (Hb) content (40 g/unit). Removal of plasma proteins was better using manual methods: residual immunoglobulin A in saline-glucose-washed cells 0.033 (0.007-0.058) mg/dL manual versus 0.064 (0.026-0.104) mg/dL ACP215 (median, range). Hb loss was lower in manually washed units (mean, ≤ 2.0g/unit) than in ACP215-washed units (mean, 6.1 g/unit). Disregarding saline-washed and stored cells, hemolysis in all nonirradiated units was less than 0.8% 14 days after washing. As expected, the use of SAGM to store manually washed units improved adenosine triphosphate, glucose, lactate, and pH versus storage in saline.The data suggest that the shelf life of manually washed RBCs could be extended to 14 days if stored in SAGM instead of saline.

BACKGROUND: Current blood prescription in cardiac surgery is based largely on hemoglobin (Hb) concentration. Hb may not provide a reliable guide to the patient's red cell (RBC) volume (RCV) during cardiac surgery as a consequence of the high fluid loads infused. This study provides estimates of the perioperative changes in RCV, plasma volume (PV), and blood volume (BV) with a view to developing a more accurate way of assessing a patient's need for transfusion. STUDY DESIGN AND METHODS: Thirty adult elective cardiac surgery patients were recruited to the study. The preoperative RCV was calculated by use of a standard nomogram. Losses and gains in RCV at several time points were added or subtracted from the baseline value. Estimates of PV and BV were derived from patient hematocrit level and RCV for each time point. RESULTS: The greatest perioperative loss of RCV occurred during cardiopulmonary bypass (CPB); however, half of this loss was returned to the patient at the end of CPB. A net gain of RCV occurred during the period of intensive care management. PV and BV showed two distinct peaks, immediately after CPB and at 16 hours after intensive therapy unit return. CONCLUSIONS: PV and BV expansion are significant factors that may lead to a Hb value that is misleadingly low in that it overestimates the decrease in RCV. This effect could lead to unnecessary transfusion if the RBC transfusion threshold is based only on Hb concentration.

Red blood cell (RBC) depletion is a standard technique for preparation of ABO-incompatible bone marrow transplants (BMTs). Density centrifugation or apheresis are used successfully at clinical scale. The advent of a bone marrow (BM) processing module for the Spectra Optia (Terumo BCT) provided the initiative to formally compare our standard technology, the COBE2991 (Ficoll, manual, "C") with the Spectra Optia BMP (apheresis, semiautomatic, "O"), the Sepax II NeatCell (Ficoll, automatic, "S"), the Miltenyi CliniMACS Prodigy density gradient separation system (Ficoll, automatic, "P"), and manual Ficoll ("M"). C and O handle larger product volumes than S, P, and M.Technologies were assessed for RBC depletion, target cell (mononuclear cells [MNCs] for buffy coats [BCs], CD34+ cells for BM) recovery, and cost/labor. BC pools were simultaneously purged with C, O, S, and P; five to 18 BM samples were sequentially processed with C, O, S, and M.Mean RBC removal with C was 97% (BCs) or 92% (BM). From both products, O removed 97%, and P, S, and M removed 99% of RBCs. MNC recovery from BC (98% C, 97% O, 65% P, 74% S) or CD34+ cell recovery from BM (92% C, 90% O, 67% S, 70% M) were best with C and O. Polymorphonuclear cells (PMNs) were depleted from BCs by P, S, and C, while O recovered 50% of PMNs. Time savings compared to C or M for all tested technologies are considerable.All methods are in principle suitable and can be selected based on sample volume, available technology, and desired product specifications beyond RBC depletion and MNC and/or CD34+ cell recovery.

Almost 90% of extremely low birthweight infants receive red blood cell (RBC) transfusion during their stay in the neonatal unit (NNU). Currently most NNUs use a combination of clinical signs and laboratory findings such as hemoglobin (Hb), hematocrit (Hct), and cardiorespiratory or ventilation status to decide the need for RBC transfusion. Various other laboratory (lactate, reticulocyte count, RBC volume) and bedside measurements (near infrared spectroscopy and Doppler ultrasound scan) have been investigated to identify a suitable trigger for RBC transfusion in newborn infants. The evidence to apply any of these investigations or measurements to clinical practice is lacking. Further research is required to identify a suitable biomarker for RBC transfusion in newborn infants.

There is growing interest in radio frequency identification (RFID) technology for tracking blood products to improve productivity and safety in the transfusion medicine supply chain. We conducted a limited study to assess the temperature and biologic effects after extreme exposure to 13.56-MHz RF radiation on aged red blood cells (aRBCs) nearing their 42-day life and three types of thawed plasma (TP).Using a Food and Drug Administration-approved limit test protocol, test units of both aRBCs and three types of TP were subjected to high levels of RF energy for an extended duration to assess worst-case effects compared to minimally exposed control units. Three replications were performed for each product type.Hemolysis after 23 to 25 hours of RF energy exposure was less than 0.3% for all test and control aRBC units and well within the 1% or less acceptance criterion. Both biologic test and temperature increase results were within acceptance criteria and consistent with earlier tests on 6- to 9-day RBCs, with no detectable acceleration in cellular degradation of aRBCs. Nine different plasma coagulation factors were evaluated and, with one explainable exception, all showed less than 20% change in their measured test versus control values, meeting the acceptance criteria. The relative temperature increase between test and control units never exceeded the 1.5°C acceptance criterion for RBCs and 4°C for plasma.Use of 13.56-MHz RFID technology is unlikely to have any significant temperature or biologic effects on aRBC and plasma units under normal operating conditions.

Anemia is a serious problem in critically ill neonates. To investigate the pathophysiology of anemia and responses to red blood cell (RBC) transfusions and erythropoietin therapy, repeated measurement of red blood cell volume (RCV) and blood volume is useful. To extend our previous sheep study in which RBCs were labeled at four different biotin densities, we assessed the validity of this multidensity method for in vivo measurement of circulating RCV in humans.In eight healthy adults, autologous RBCs were biotinylated at each of four biotin densities (6, 18, 54, and 162 µg biotinylation reagent/mL RBC), mixed, and infused intravenously; blood was sampled at 10, 20, and 60 minutes. At each time, RCV was calculated from dilution of individual RBC populations enumerated by flow cytometry. RCV measurements from the population of RBCs biotinylated at 6 µg/mL were chosen as the reference values because this density had been previously validated against the 51Cr method in vitro and in vivo in humans.Values for RCVs were not significantly different among the four densities of biotinylated RBCs at any of the three time points and did not change over 60 minutes.These studies provide evidence that four densities of biotinylated RBCs can be used in vivo for simultaneous, independent, accurate measurements of RCV in humans. We speculate that this method will also be useful for repeated measurement of RCV and blood volume in infants and other patient populations in whom radioactive labels should be avoided.

Advances in neonatal medicine include therapies that have resulted in improved survival and outcome of extremely low birth weight (

BACKGROUND: The transfusion trigger that physicians use to determine whether a patient requires a red blood cell (RBC) transfusion is the peripheral venous hematocrit (Hct) value. Although this measurement is an indicator of the concentration of RBCs in the blood, it does not reveal the RBC volume, plasma volume, or total blood volume, nor does it give any indication of whether the patient is hypovolemic, normovolemic, or hypervolemic. STUDY DESIGN AND METHODS: Two patient populations were studied: 41 consecutive patients subjected to elective vascular surgery and 20 consecutive patients subjected to cardiopulmonary bypass surgery. The RBC volume was measured with 51Cr- or 99mTc-labeled autologous fresh RBCs, and the plasma volume and total blood volume were estimated from the measured RBC volume and the total body Hct level. Measurements made 1 to 2 and 24 hours after surgery were compared to the preoperative values for these two groups of patients. RESULTS: During the 24-hour postoperative period, the RBC, plasma, and total blood volumes were reduced compared to the preoperative volumes. These patients were hypovolemic and anemic, and their Hct values during the 24-hour postoperative period were increased by a mean of 4 to 5 volume-percent compared to values that would be expected if they were normvolemic and anemic. CONCLUSIONS: The Hct values in hypovolemic anemic patients are elevated because the plasma volume does not increase to achieve the normovolemic anemic state.

One problem assessing the hematologic physiology of preterm infants after delivery and/or the efficacy and toxicity of therapeutic interventions affecting RBC measurements is the inability of blood Hct values to accurately reflect circulating RBC volume-owing to changes in plasma volume that influence Hct (i.e., a fall in plasma volume concentrates RBCs to increase Hct; a rise in plasma volume dilutes RBCs to decrease Hct).As part of a randomized, clinical trial testing the hypothesis that delayed clamping of the umbilical cord at delivery expands neonatal circulating RBC volume, blood Hct was compared to circulating RBC volume results measured directly with autologous, biotinylated RBCs or estimated mathematically with neonatal body weight and Hct values in neonates after immediate or delayed (60 sec) cord clamping.Circulating RBC volume measured directly with biotinylated RBCs significantly increased (p=0.04) in neonates after delayed (42.1 +/- 7.8 mL/kg) versus immediate (36.8 +/- 6.3 mL/kg) cord clamping-a difference not detected indirectly by measuring Hct or estimating circulating RBC volume mathematically.Because true hematologic effects of delayed versus immediate cord clamping may not be apparent or may be misinterpreted, when based on indirect measurements of Hct or calculations of circulating RBC volume, it is important to measure circulating RBC volume directly-as done with autologous, biotinylated RBCs-to document whether delayed cord clamping truly results in a transfer of significant quantities of RBCs from placenta to neonate. The clinical benefits and potential toxicities of increased RBC transfer to neonates require further studies.

Background Multicomponent apheresis procedures offer the possibility of collecting blood components that are standardized, as compared to those available with whole-blood donations. A new separator program for the concurrent collection of RBCs, platelets, and plasma (Amicus, Baxter Healthcare) was evaluated. Study design and methods Apheresis donors (n = 47) underwent concurrent collection of RBCs, platelets, and plasma by use of the single-needle procedure of the Amicus blood cell separator. A standardized RBC volume (100% Hct) of 200 mL was targeted with either 1 or 2 platelet concentrate units, depending on the donor's predonation characteristics. After collection, the RBC component was sterilely connected to an RBC collection set (Amicus) to allow for the addition of 100 mL of saline-adenine-glucose-mannitol preservative solution and WBC reduction at either ambient temperature or 4 degrees C. The RBC units were subsequently stored at 2 to 6 degrees C for 42 days, and the following in vitro measures were evaluated over the storage period: blood cell counts including Hct and total Hb, plasma Hb, potassium, pH, ATP, and 2,3 DPG. Results Procedure time averaged 74 +/- 9 minutes, and no adverse events were reported. The absolute RBC volume collected averaged 198 +/- 11 mL with an average Hct value of 83 +/- 2 percent. After filtration, the Hb content averaged 58.2 +/- 2.4 g per unit and residual WBCs averaged 0.038 +/- 0.015 x 10(6) per unit. Day 42 results showed that all units had on average more than 70-percent ATP maintenance, and all of the units had less than 0.8 percent he-molysis. All units had pH values higher than 6.5 on Day 42. Conclusion The concurrent multicomponent collection system (Amicus) can reliably collect a standardized RBC unit of good quality. In vitro testing of the RBCs collected and stored for 42 days met the Council of Europe criteria for transfusion.

BACKGROUND: Anemia is a serious problem in the fetus and preterm infant. To investigate the physiology and pathophysiology of anemia and to assess responses to blood transfusions or erythropoietin therapy, measurement of circulating red cell volume would be useful. Because the standard 51Cr method exposes the subject to radiation, a method of measuring circulating red cell volume without radiation exposure, sufficiently sensitive for use in fetuses and infants, was developed. STUDY DESIGN AND METHODS: In 10 healthy adults whose body mass ranged from 56.8 to 115.9 kg, aliquots of autologous red cells were labeled with biotin or with 51Cr, mixed, and transfused intravenously. Circulating red cell volume was measured in posttransfusion blood by quantitating the in vivo dilution of biotinylated red cells. Biotinylated red cells were detected by two methods: 1) 125I-streptavidin and 2) fluorescein-labeled avidin with flow cytometry. RESULTS: Circulating red cell volume measured by 125I- streptavidin detection agreed well with that measured by 51Cr (slope = 1.07, y-intercept = −97, correlation = 0.987). Similarly, circulating red cell volume measured by flow cytometry agreed well with that measured by 51Cr (slope = 1.05, y-intercept = −20, correlation = 0.987). CONCLUSIONS: Circulating red cell volume measured by the use of biotin with either 125I-streptavidin or flow cytometry agrees with that measured by 51Cr. Each system provides a method of performing these studies without exposing the subject to radiation.

A recently developed nonradioisotopic 52Cr technique was used to measure either red cell volume or posttransfusion recovery of stored red cells. The experimental method uses Zeeman electrothermal atomic absorption spectrophotometry to measure red cell chromium. Results from the 52Cr method were compared with those from 51Cr single-label and 125I-albumin/51Cr double-label procedures using 49-day AS-1 red cell concentrates drawn and prepared according to standard procedures. In the first group of five donors, red cell volume was estimated concurrently with both 52Cr-labeled fresh red cells and 125I-albumin. The latter measured plasma volume from which red cell volume was estimated on the basis of the hematocrit (125I red cell volume). 51Cr-labeled stored red cells were transfused to measure posttransfusion recoveries. The correlation between 52Cr and 125I red cell volumes was significant (r = 0.68, p less than 0.01), and, in this group, the differences were not significant (p less than 0.05). Twenty-four-hour posttransfusion recoveries of 51Cr-labeled stored red cells averaged 66 +/- 5 percent when measured with the 125I/51Cr technique and 69 +/- 8 percent when measured with the 52Cr/51Cr method. In the second group of five donors, red cell volume was estimated by the 125I-albumin technique, and the posttransfusion recovery of stored red cells was quantitated by 51Cr- and 52Cr-labeled stored cells simultaneously. In this group, posttransfusion recoveries with 125I/51Cr averaged 73 +/- 7 percent; with 125I/52Cr, they averaged 75 +/- 10 percent. Using the single-label method of calculation, recoveries averaged 76 +/- 7 and 75 +/- 10 percent for the 51Cr and 52Cr methods, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemolytic reactions caused by transfusion of ABO-incompatible marrow can be ameliorated by either reduction of isohemagglutinins in the recipient or depletion of incompatible red cells from the harvested marrow. This article describes a rapid and reliable method for removal of incompatible marrow red cells on a blood cell processor using a double buffy coat technique. In five allogeneic bone marrow transplants, the maximum value of transfused incompatible red cells was 8.8 ml. There was no evidence of a hemolytic transfusion reaction in any patient. The median cell recovery for nucleated marrow cells and progenitor cells was 77 and 104 percent, respectively. Engraftment occurred at a median of 13 days (range, 11-21 days) after transplantation. The double buffy coat method of red cell depletion is an acceptable method for processing ABO-incompatible marrow.

When red cells are stored as suspensions in artificial preservative solutions such as those consisting of saline, adenine, and glucose, increased hemolysis of the red cells occurs in vitro, a phenomenon that is readily prevented by the addition of mannitol. The mechanism by which mannitol prevents hemolysis is unknown. The authors have examined the possibility that mannitol prevents hemolysis by prevention of osmotic swelling of red cells that might otherwise increase their volume beyond their critical hemolytic volume. Storage in artificial media does, indeed, result in swelling of the red cells, which is prevented by mannitol and is increased by the addition of nystatin, an agent that greatly increases the sodium-potassium permeability of the cells. Swelling and hemolysis are correlated at different concentrations of mannitol, but the correlation breaks down when the case of nystatin-treated cells is considered; even with marked swelling, there is relatively little hemolysis. Moreover, increasing the volume of the stored red cells acutely by osmotic means results in relatively little additional hemolysis. These findings make it appear unlikely that simple osmotic lysis is the cause of hemolysis in stored cells. Some other stabilizing effect of mannitol that may or may not be related to its osmotic effect must play a role.

A single-isotope 51Cr method often is used to evaluate the viability of stored red cells. In this technique, the red cell mass is measured by back-extrapolation to time zero (t0) of the radioactivity of the blood between 5 and 20 minutes after infusion of the sample. If there is early destruction of stored cells, this method provides an overestimate of the red cell mass and, hence, of the viability of the stored cells. Freshly drawn red cells from normal donors were labeled with 99mTc, and cells from the same donor which had been stored in citrate-phosphate- dextrose-adenine-one (CPDA-1) for periods ranging from 7 to 49 days were labeled with 51Cr. A comparison of the “true red cell mass” as determined with 99mTc with the back-extrapolated red cell mass from stored 51Cr-labeled cells has made it possible to define the magnitude of error introduced by early loss of red cells. The overestimation of red cell mass and viability was diminished if only the 51Cr radioactivity between 5 and 15 minutes after infusion was used in back- extrapolating to t0. The degree of overestimation of red cell mass was greatest when the red cell viability had declined to very low levels. However, in the entire range of 10 to 80 percent viability, the overestimate of viability was usually less than 4 percent. The overestimate of viability proved to be quite similar for all samples and may be taken into account when using the single-isotope technique for measurement of red cell viability.(ABSTRACT TRUNCATED AT 250 WORDS)

A nonradioisotopic method for measuring red cell volume that involves the use of 52Cr-sodium chromate as the red cell label and of graphite furnace atomic absorption analysis of chromium is described. The technique allows the labelling of 20 mL of packed red cells with 40 to 50 micrograms of sodium chromate (Na2CrO4) in 30 minutes at 22 degrees C with 94 +/- 6 percent uptake. Approximately 40 micrograms of Na2CrO4 was injected for in vivo studies. This results in posttransfusion in vivo red cell chromium levels after sample processing in the range of 1 to 7 micrograms per L, which could be quantitated accurately (coefficient of variation = 4.7%) by Zeeman electrothermal atomic absorption spectrophotometry. The labeling concentration of chromium did not cause increased hemolysis, and the labeled cells exhibited an osmotic fragility curve similar to that of unlabeled, fresh ACD red cells. Red cell glutathione peroxidase was unaffected by labeling, although glutathione reductase was reduced by approximately 13 percent (p less than 0.05). The 52Cr red cell volume-measuring method was evaluated by concurrent in vivo studies with the standard 51Cr and 125I-albumin methods for that procedure. Simultaneous measurement of red cell volumes in seven volunteers by the 51Cr, 52Cr, and 125I-albumin techniques correlated highly with each other (r greater than 0.76), with mean values of 2294 +/- 199, 2191 +/- 180, and 2243 +/- 291 mL, respectively. The standard deviations of the differences were small: 134 mL for 52Cr versus 51Cr and 183 mL for 52Cr versus 125I.(ABSTRACT TRUNCATED AT 250 WORDS)