Neil Blumberg

Sickle trait cells do not sickle under physiologic conditions compatible with life.  Purely a theoretical construct.  Oxygen transport is also normal under physiologic conditions compatible with life. The evidence that sickle trait cells present any risks to any patient through transfusion is exactly zero.  Patients with sickle trait rarely, if ever, have any problems attributable to sickle trait. The epidemiologic evidence is likewise weak, if not zero.

Those are theoretical constructs. The data suggest fresh isn't best if there are more infections as there have been in randomized trials of fresh vs. average storage period.  More study needed, but the data are more important than the dogma.  Infection is the most common cause of morbidity and mortality in all hospital patients, including newborns.

Sickle trait cells do not sickle under physiologic conditions compatible with life.  Purely a theoretical construct.  Oxygen transport is also normal under physiologic conditions compatible with life. The evidence that sickle trait cells present any risks to any patient through transfusion is exactly zero.  Patients with sickle trait rarely, if ever, have any problems attributable to sickle trait. The epidemiologic evidence is likewise weak, if not zero.

Sickle trait cells do not sickle under physiologic conditions compatible with life.  Purely a theoretical construct.  Oxygen transport is also normal under physiologic conditions compatible with life. The evidence that sickle trait cells present any risks to any patient through transfusion is exactly zero.  Patients with sickle trait rarely, if ever, have any problems attributable to sickle trait. The epidemiologic evidence is likewise weak, if not zero.

Sickle trait cells do not sickle under physiologic conditions compatible with life.  Purely a theoretical construct.  Oxygen transport is also normal under physiologic conditions compatible with life. The evidence that sickle trait cells present any risks to any patient through transfusion is exactly zero.  Patients with sickle trait rarely, if ever, have any problems attributable to sickle trait. The epidemiologic evidence is likewise weak, if not zero.

There is reason NOT to use the freshest possible units. They may be more toxic than intermediate stored units. This is something that made sense but was almost certainly wrong.  See below for the reasoning and published data.  We use <21 days as fresh for this reason and avoid <7 days storage for everyone based upon the randomized trial data.
BMJ 2019;366:l4968 doi: 10.1136/bmj.l4968 (Published 5 August 2019) Page 1 of 1
Letters
Trivella and colleagues present some caveats around the subject of duration of red cell storage and clinical outcomes.1 Studies have been widely interpreted as showing that transfusion is not associated with adverse clinical outcomes. I think this is a serious misinterpretation of the data.
In addition to the concerns raised by the authors, another valid hypothesis, which has received little attention, is that very short storage red cells might be more dangerous than medium storage periods (say 7-21 days) and equally dangerous as longer storage red cells (say 28-42 days). An inverted U shaped curve. The evidence for this comes from a meta-analysis finding that “ultra short” storage of red cells was associated with a post-transfusion increase in nosocomial infection.2 Shorter storage red cells have a greater imbalance of oxidation-reduction potential than longer storage red cells in preliminary studies in vitro.3 Red cell storage duration is also a poor predictor of post-transfusion free haemoglobin and heme, putative mediators of toxicity from transfusions.4 5
We need better metrics for predicting red cell transfusion efficacy and toxicity. The simple expedient of fresher red cells is clearly not that metric and might be leading us to transfuse more toxic red cells (very fresh) in the most fragile patients,
such as premature newborns. A new approach is clearly called for by the current data. At our centre we define fresh as <21 days of storage, and we generally never transfuse a red cell that has been stored for much less than 7-10 days, for the above reasons as well as logistics of supply.
Competing interests: None declared.
1 Trivella M, Stanworth SJ, Brunskill S, Dutton P, Altman DG. Can we be certain that storage duration of transfused red blood cells does not affect patient outcomes?BMJ 2019;365:l2320. 10.1136/bmj.l2320 31186250
2 Alexander PE, Barty R, Fei Y, etal . Transfusion of fresher vs older red blood cells in hospitalized patients: a systematic review and meta-analysis. Blood 2016;127:400-10. 10.1182/blood-2015-09-670950 26626995
3 Schmidt A, Gore E, Cholette JM, etal . Oxidation reduction potential (ORP) is predictive of complications following cardiac surgery in pediatric patients[abstract]. Transfusion 2016;56(Supplement S4):20A-1A.
4 Cholette JM, Pietropaoli AP, Henrichs KF, etal . Elevated free hemoglobin and decreased haptoglobin levels are associated with adverse clinical outcomes, unfavorable physiologic measures, and altered inflammatory markers in pediatric cardiac surgery patients. Transfusion 2018;58:1631-9. 10.1111/trf.14601 29603246
5 Pietropaoli AP, Henrichs KF, Cholette JM, etal . Total plasma heme concentration increases after red blood cell transfusion and predicts mortality in critically ill medical patients. Transfusion 2019;59:2007-15. 10.1111/trf.15218 30811035
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/ permissions
LETTERS

We use either ABO identical or washed O red cells.  Usually volume reduced so the hematocrit is around 70-80% either by centrifugation or washing with Plasmalyte.  We have data that saline washing is likely associated with more hemolysis and metabolic acidosis.  Leukoreduced and <21 days old.
We prefer not to use the very short storage red cells (<7 days) as there is evidence they are more dangerous from randomized trials, albeit in mostly adult patients. 
We do not CMV test or test for hemoglobin S, except for exchange transfusions.  No evidence that hemoglobin S trait is a problem for transfusion in any situation, but particularly for smaller volume transfusions.
We do irradiate for newborns since immunodeficiencies, while very rare, are often not diagnosed until later in infancy or early childhood.

We use either ABO identical or washed O red cells.  Usually volume reduced so the hematocrit is around 70-80% either by centrifugation or washing with Plasmalyte.  We have data that saline washing is likely associated with more hemolysis and metabolic acidosis.  Leukoreduced and <21 days old.
We prefer not to use the very short storage red cells (<7 days) as there is evidence they are more dangerous from randomized trials, albeit in mostly adult patients. 
We do not CMV test or test for hemoglobin S, except for exchange transfusions.  No evidence that hemoglobin S trait is a problem for transfusion in any situation, but particularly for smaller volume transfusions.
We do irradiate for newborns since immunodeficiencies, while very rare, are often not diagnosed until later in infancy or early childhood.

If the unit if leukoreduced, as all red cell transfusions should be, there is no need for CMV negative in my view.  

There is reason NOT to use the freshest possible units. They may be more toxic than intermediate stored units. This is something that made sense but was almost certainly wrong.  See below for the reasoning and published data.  We use <21 days as fresh for this reason and avoid <7 days storage for everyone based upon the randomized trial data.
BMJ 2019;366:l4968 doi: 10.1136/bmj.l4968 (Published 5 August 2019) Page 1 of 1
Letters
Trivella and colleagues present some caveats around the subject of duration of red cell storage and clinical outcomes.1 Studies have been widely interpreted as showing that transfusion is not associated with adverse clinical outcomes. I think this is a serious misinterpretation of the data.
In addition to the concerns raised by the authors, another valid hypothesis, which has received little attention, is that very short storage red cells might be more dangerous than medium storage periods (say 7-21 days) and equally dangerous as longer storage red cells (say 28-42 days). An inverted U shaped curve. The evidence for this comes from a meta-analysis finding that “ultra short” storage of red cells was associated with a post-transfusion increase in nosocomial infection.2 Shorter storage red cells have a greater imbalance of oxidation-reduction potential than longer storage red cells in preliminary studies in vitro.3 Red cell storage duration is also a poor predictor of post-transfusion free haemoglobin and heme, putative mediators of toxicity from transfusions.4 5
We need better metrics for predicting red cell transfusion efficacy and toxicity. The simple expedient of fresher red cells is clearly not that metric and might be leading us to transfuse more toxic red cells (very fresh) in the most fragile patients,
such as premature newborns. A new approach is clearly called for by the current data. At our centre we define fresh as <21 days of storage, and we generally never transfuse a red cell that has been stored for much less than 7-10 days, for the above reasons as well as logistics of supply.
Competing interests: None declared.
1 Trivella M, Stanworth SJ, Brunskill S, Dutton P, Altman DG. Can we be certain that storage duration of transfused red blood cells does not affect patient outcomes?BMJ 2019;365:l2320. 10.1136/bmj.l2320 31186250
2 Alexander PE, Barty R, Fei Y, etal . Transfusion of fresher vs older red blood cells in hospitalized patients: a systematic review and meta-analysis. Blood 2016;127:400-10. 10.1182/blood-2015-09-670950 26626995
3 Schmidt A, Gore E, Cholette JM, etal . Oxidation reduction potential (ORP) is predictive of complications following cardiac surgery in pediatric patients[abstract]. Transfusion 2016;56(Supplement S4):20A-1A.
4 Cholette JM, Pietropaoli AP, Henrichs KF, etal . Elevated free hemoglobin and decreased haptoglobin levels are associated with adverse clinical outcomes, unfavorable physiologic measures, and altered inflammatory markers in pediatric cardiac surgery patients. Transfusion 2018;58:1631-9. 10.1111/trf.14601 29603246
5 Pietropaoli AP, Henrichs KF, Cholette JM, etal . Total plasma heme concentration increases after red blood cell transfusion and predicts mortality in critically ill medical patients. Transfusion 2019;59:2007-15. 10.1111/trf.15218 30811035
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/ permissions
LETTERS

There is reason NOT to use the freshest possible units. They may be more toxic than intermediate stored units. This is something that made sense but was almost certainly wrong.  See below for the reasoning and published data.  We use <21 days as fresh for this reason and avoid <7 days storage for everyone based upon the randomized trial data.
BMJ 2019;366:l4968 doi: 10.1136/bmj.l4968 (Published 5 August 2019) Page 1 of 1
Letters
Trivella and colleagues present some caveats around the subject of duration of red cell storage and clinical outcomes.1 Studies have been widely interpreted as showing that transfusion is not associated with adverse clinical outcomes. I think this is a serious misinterpretation of the data.
In addition to the concerns raised by the authors, another valid hypothesis, which has received little attention, is that very short storage red cells might be more dangerous than medium storage periods (say 7-21 days) and equally dangerous as longer storage red cells (say 28-42 days). An inverted U shaped curve. The evidence for this comes from a meta-analysis finding that “ultra short” storage of red cells was associated with a post-transfusion increase in nosocomial infection.2 Shorter storage red cells have a greater imbalance of oxidation-reduction potential than longer storage red cells in preliminary studies in vitro.3 Red cell storage duration is also a poor predictor of post-transfusion free haemoglobin and heme, putative mediators of toxicity from transfusions.4 5
We need better metrics for predicting red cell transfusion efficacy and toxicity. The simple expedient of fresher red cells is clearly not that metric and might be leading us to transfuse more toxic red cells (very fresh) in the most fragile patients,
such as premature newborns. A new approach is clearly called for by the current data. At our centre we define fresh as <21 days of storage, and we generally never transfuse a red cell that has been stored for much less than 7-10 days, for the above reasons as well as logistics of supply.
Competing interests: None declared.
1 Trivella M, Stanworth SJ, Brunskill S, Dutton P, Altman DG. Can we be certain that storage duration of transfused red blood cells does not affect patient outcomes?BMJ 2019;365:l2320. 10.1136/bmj.l2320 31186250
2 Alexander PE, Barty R, Fei Y, etal . Transfusion of fresher vs older red blood cells in hospitalized patients: a systematic review and meta-analysis. Blood 2016;127:400-10. 10.1182/blood-2015-09-670950 26626995
3 Schmidt A, Gore E, Cholette JM, etal . Oxidation reduction potential (ORP) is predictive of complications following cardiac surgery in pediatric patients[abstract]. Transfusion 2016;56(Supplement S4):20A-1A.
4 Cholette JM, Pietropaoli AP, Henrichs KF, etal . Elevated free hemoglobin and decreased haptoglobin levels are associated with adverse clinical outcomes, unfavorable physiologic measures, and altered inflammatory markers in pediatric cardiac surgery patients. Transfusion 2018;58:1631-9. 10.1111/trf.14601 29603246
5 Pietropaoli AP, Henrichs KF, Cholette JM, etal . Total plasma heme concentration increases after red blood cell transfusion and predicts mortality in critically ill medical patients. Transfusion 2019;59:2007-15. 10.1111/trf.15218 30811035
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/ permissions
LETTERS

There is reason NOT to use the freshest possible units. They may be more toxic than intermediate stored units. This is something that made sense but was almost certainly wrong.  See below for the reasoning and published data.  We use <21 days as fresh for this reason and avoid <7 days storage for everyone based upon the randomized trial data.
BMJ 2019;366:l4968 doi: 10.1136/bmj.l4968 (Published 5 August 2019) Page 1 of 1
Letters
Trivella and colleagues present some caveats around the subject of duration of red cell storage and clinical outcomes.1 Studies have been widely interpreted as showing that transfusion is not associated with adverse clinical outcomes. I think this is a serious misinterpretation of the data.
In addition to the concerns raised by the authors, another valid hypothesis, which has received little attention, is that very short storage red cells might be more dangerous than medium storage periods (say 7-21 days) and equally dangerous as longer storage red cells (say 28-42 days). An inverted U shaped curve. The evidence for this comes from a meta-analysis finding that “ultra short” storage of red cells was associated with a post-transfusion increase in nosocomial infection.2 Shorter storage red cells have a greater imbalance of oxidation-reduction potential than longer storage red cells in preliminary studies in vitro.3 Red cell storage duration is also a poor predictor of post-transfusion free haemoglobin and heme, putative mediators of toxicity from transfusions.4 5
We need better metrics for predicting red cell transfusion efficacy and toxicity. The simple expedient of fresher red cells is clearly not that metric and might be leading us to transfuse more toxic red cells (very fresh) in the most fragile patients,
such as premature newborns. A new approach is clearly called for by the current data. At our centre we define fresh as <21 days of storage, and we generally never transfuse a red cell that has been stored for much less than 7-10 days, for the above reasons as well as logistics of supply.
Competing interests: None declared.
1 Trivella M, Stanworth SJ, Brunskill S, Dutton P, Altman DG. Can we be certain that storage duration of transfused red blood cells does not affect patient outcomes?BMJ 2019;365:l2320. 10.1136/bmj.l2320 31186250
2 Alexander PE, Barty R, Fei Y, etal . Transfusion of fresher vs older red blood cells in hospitalized patients: a systematic review and meta-analysis. Blood 2016;127:400-10. 10.1182/blood-2015-09-670950 26626995
3 Schmidt A, Gore E, Cholette JM, etal . Oxidation reduction potential (ORP) is predictive of complications following cardiac surgery in pediatric patients[abstract]. Transfusion 2016;56(Supplement S4):20A-1A.
4 Cholette JM, Pietropaoli AP, Henrichs KF, etal . Elevated free hemoglobin and decreased haptoglobin levels are associated with adverse clinical outcomes, unfavorable physiologic measures, and altered inflammatory markers in pediatric cardiac surgery patients. Transfusion 2018;58:1631-9. 10.1111/trf.14601 29603246
5 Pietropaoli AP, Henrichs KF, Cholette JM, etal . Total plasma heme concentration increases after red blood cell transfusion and predicts mortality in critically ill medical patients. Transfusion 2019;59:2007-15. 10.1111/trf.15218 30811035
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/ permissions
LETTERS

There is reason NOT to use the freshest possible units. They may be more toxic than intermediate stored units. This is something that made sense but was almost certainly wrong.  See below for the reasoning and published data.  We use <21 days as fresh for this reason and avoid <7 days storage for everyone based upon the randomized trial data.
BMJ 2019;366:l4968 doi: 10.1136/bmj.l4968 (Published 5 August 2019) Page 1 of 1
Letters
Trivella and colleagues present some caveats around the subject of duration of red cell storage and clinical outcomes.1 Studies have been widely interpreted as showing that transfusion is not associated with adverse clinical outcomes. I think this is a serious misinterpretation of the data.
In addition to the concerns raised by the authors, another valid hypothesis, which has received little attention, is that very short storage red cells might be more dangerous than medium storage periods (say 7-21 days) and equally dangerous as longer storage red cells (say 28-42 days). An inverted U shaped curve. The evidence for this comes from a meta-analysis finding that “ultra short” storage of red cells was associated with a post-transfusion increase in nosocomial infection.2 Shorter storage red cells have a greater imbalance of oxidation-reduction potential than longer storage red cells in preliminary studies in vitro.3 Red cell storage duration is also a poor predictor of post-transfusion free haemoglobin and heme, putative mediators of toxicity from transfusions.4 5
We need better metrics for predicting red cell transfusion efficacy and toxicity. The simple expedient of fresher red cells is clearly not that metric and might be leading us to transfuse more toxic red cells (very fresh) in the most fragile patients,
such as premature newborns. A new approach is clearly called for by the current data. At our centre we define fresh as <21 days of storage, and we generally never transfuse a red cell that has been stored for much less than 7-10 days, for the above reasons as well as logistics of supply.
Competing interests: None declared.
1 Trivella M, Stanworth SJ, Brunskill S, Dutton P, Altman DG. Can we be certain that storage duration of transfused red blood cells does not affect patient outcomes?BMJ 2019;365:l2320. 10.1136/bmj.l2320 31186250
2 Alexander PE, Barty R, Fei Y, etal . Transfusion of fresher vs older red blood cells in hospitalized patients: a systematic review and meta-analysis. Blood 2016;127:400-10. 10.1182/blood-2015-09-670950 26626995
3 Schmidt A, Gore E, Cholette JM, etal . Oxidation reduction potential (ORP) is predictive of complications following cardiac surgery in pediatric patients[abstract]. Transfusion 2016;56(Supplement S4):20A-1A.
4 Cholette JM, Pietropaoli AP, Henrichs KF, etal . Elevated free hemoglobin and decreased haptoglobin levels are associated with adverse clinical outcomes, unfavorable physiologic measures, and altered inflammatory markers in pediatric cardiac surgery patients. Transfusion 2018;58:1631-9. 10.1111/trf.14601 29603246
5 Pietropaoli AP, Henrichs KF, Cholette JM, etal . Total plasma heme concentration increases after red blood cell transfusion and predicts mortality in critically ill medical patients. Transfusion 2019;59:2007-15. 10.1111/trf.15218 30811035
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/ permissions
LETTERS

There is reason NOT to use the freshest possible units. They may be more toxic than intermediate stored units. This is something that made sense but was almost certainly wrong.  See below for the reasoning and published data.  We use <21 days as fresh for this reason and avoid <7 days storage for everyone based upon the randomized trial data.
BMJ 2019;366:l4968 doi: 10.1136/bmj.l4968 (Published 5 August 2019) Page 1 of 1
Letters
Trivella and colleagues present some caveats around the subject of duration of red cell storage and clinical outcomes.1 Studies have been widely interpreted as showing that transfusion is not associated with adverse clinical outcomes. I think this is a serious misinterpretation of the data.
In addition to the concerns raised by the authors, another valid hypothesis, which has received little attention, is that very short storage red cells might be more dangerous than medium storage periods (say 7-21 days) and equally dangerous as longer storage red cells (say 28-42 days). An inverted U shaped curve. The evidence for this comes from a meta-analysis finding that “ultra short” storage of red cells was associated with a post-transfusion increase in nosocomial infection.2 Shorter storage red cells have a greater imbalance of oxidation-reduction potential than longer storage red cells in preliminary studies in vitro.3 Red cell storage duration is also a poor predictor of post-transfusion free haemoglobin and heme, putative mediators of toxicity from transfusions.4 5
We need better metrics for predicting red cell transfusion efficacy and toxicity. The simple expedient of fresher red cells is clearly not that metric and might be leading us to transfuse more toxic red cells (very fresh) in the most fragile patients,
such as premature newborns. A new approach is clearly called for by the current data. At our centre we define fresh as <21 days of storage, and we generally never transfuse a red cell that has been stored for much less than 7-10 days, for the above reasons as well as logistics of supply.
Competing interests: None declared.
1 Trivella M, Stanworth SJ, Brunskill S, Dutton P, Altman DG. Can we be certain that storage duration of transfused red blood cells does not affect patient outcomes?BMJ 2019;365:l2320. 10.1136/bmj.l2320 31186250
2 Alexander PE, Barty R, Fei Y, etal . Transfusion of fresher vs older red blood cells in hospitalized patients: a systematic review and meta-analysis. Blood 2016;127:400-10. 10.1182/blood-2015-09-670950 26626995
3 Schmidt A, Gore E, Cholette JM, etal . Oxidation reduction potential (ORP) is predictive of complications following cardiac surgery in pediatric patients[abstract]. Transfusion 2016;56(Supplement S4):20A-1A.
4 Cholette JM, Pietropaoli AP, Henrichs KF, etal . Elevated free hemoglobin and decreased haptoglobin levels are associated with adverse clinical outcomes, unfavorable physiologic measures, and altered inflammatory markers in pediatric cardiac surgery patients. Transfusion 2018;58:1631-9. 10.1111/trf.14601 29603246
5 Pietropaoli AP, Henrichs KF, Cholette JM, etal . Total plasma heme concentration increases after red blood cell transfusion and predicts mortality in critically ill medical patients. Transfusion 2019;59:2007-15. 10.1111/trf.15218 30811035
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/ permissions
LETTERS

There is reason NOT to use the freshest possible units. They may be more toxic than intermediate stored units. This is something that made sense but was almost certainly wrong.  See below for the reasoning and published data.  We use <21 days as fresh for this reason and avoid <7 days storage for everyone based upon the randomized trial data.
BMJ 2019;366:l4968 doi: 10.1136/bmj.l4968 (Published 5 August 2019) Page 1 of 1
Letters
Trivella and colleagues present some caveats around the subject of duration of red cell storage and clinical outcomes.1 Studies have been widely interpreted as showing that transfusion is not associated with adverse clinical outcomes. I think this is a serious misinterpretation of the data.
In addition to the concerns raised by the authors, another valid hypothesis, which has received little attention, is that very short storage red cells might be more dangerous than medium storage periods (say 7-21 days) and equally dangerous as longer storage red cells (say 28-42 days). An inverted U shaped curve. The evidence for this comes from a meta-analysis finding that “ultra short” storage of red cells was associated with a post-transfusion increase in nosocomial infection.2 Shorter storage red cells have a greater imbalance of oxidation-reduction potential than longer storage red cells in preliminary studies in vitro.3 Red cell storage duration is also a poor predictor of post-transfusion free haemoglobin and heme, putative mediators of toxicity from transfusions.4 5
We need better metrics for predicting red cell transfusion efficacy and toxicity. The simple expedient of fresher red cells is clearly not that metric and might be leading us to transfuse more toxic red cells (very fresh) in the most fragile patients,
such as premature newborns. A new approach is clearly called for by the current data. At our centre we define fresh as <21 days of storage, and we generally never transfuse a red cell that has been stored for much less than 7-10 days, for the above reasons as well as logistics of supply.
Competing interests: None declared.
1 Trivella M, Stanworth SJ, Brunskill S, Dutton P, Altman DG. Can we be certain that storage duration of transfused red blood cells does not affect patient outcomes?BMJ 2019;365:l2320. 10.1136/bmj.l2320 31186250
2 Alexander PE, Barty R, Fei Y, etal . Transfusion of fresher vs older red blood cells in hospitalized patients: a systematic review and meta-analysis. Blood 2016;127:400-10. 10.1182/blood-2015-09-670950 26626995
3 Schmidt A, Gore E, Cholette JM, etal . Oxidation reduction potential (ORP) is predictive of complications following cardiac surgery in pediatric patients[abstract]. Transfusion 2016;56(Supplement S4):20A-1A.
4 Cholette JM, Pietropaoli AP, Henrichs KF, etal . Elevated free hemoglobin and decreased haptoglobin levels are associated with adverse clinical outcomes, unfavorable physiologic measures, and altered inflammatory markers in pediatric cardiac surgery patients. Transfusion 2018;58:1631-9. 10.1111/trf.14601 29603246
5 Pietropaoli AP, Henrichs KF, Cholette JM, etal . Total plasma heme concentration increases after red blood cell transfusion and predicts mortality in critically ill medical patients. Transfusion 2019;59:2007-15. 10.1111/trf.15218 30811035
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/ permissions
LETTERS

If the unit if leukoreduced, as all red cell transfusions should be, there is no need for CMV negative in my view.  

If the unit if leukoreduced, as all red cell transfusions should be, there is no need for CMV negative in my view.  

If the unit if leukoreduced, as all red cell transfusions should be, there is no need for CMV negative in my view.  

If the unit if leukoreduced, as all red cell transfusions should be, there is no need for CMV negative in my view.  

If the unit if leukoreduced, as all red cell transfusions should be, there is no need for CMV negative in my view.  

If the unit if leukoreduced, as all red cell transfusions should be, there is no need for CMV negative in my view.  

If the unit if leukoreduced, as all red cell transfusions should be, there is no need for CMV negative in my view.  

This is a clinical call that we make between the senior medical technical staff present and the attending physician.  We routinely switch male patients, and older females who are Rh negative to Rh positive red cells when transfusion rate is significant and supply constrained. No policy.  Just a clinical decision, which we communicate to the treating team.  Typically a liver transplant that has gone badly, an exsanguinating trauma patient and similar situations.

We use either ABO identical or washed O red cells.  Usually volume reduced so the hematocrit is around 70-80% either by centrifugation or washing with Plasmalyte.  We have data that saline washing is likely associated with more hemolysis and metabolic acidosis.  Leukoreduced and <21 days old.
We prefer not to use the very short storage red cells (<7 days) as there is evidence they are more dangerous from randomized trials, albeit in mostly adult patients. 
We do not CMV test or test for hemoglobin S, except for exchange transfusions.  No evidence that hemoglobin S trait is a problem for transfusion in any situation, but particularly for smaller volume transfusions.
We do irradiate for newborns since immunodeficiencies, while very rare, are often not diagnosed until later in infancy or early childhood.

This is a clinical call that we make between the senior medical technical staff present and the attending physician.  We routinely switch male patients, and older females who are Rh negative to Rh positive red cells when transfusion rate is significant and supply constrained. No policy.  Just a clinical decision, which we communicate to the treating team.  Typically a liver transplant that has gone badly, an exsanguinating trauma patient and similar situations.