Volume 19 Number 3
CORRESPONDENCE
3. Graw, R. G., G. Herzig, S. Perry, and E. S. Henderson: Normal granulocyte transfusion therapy. Treatment of septicemia due to gram-negative bacteria. N. Engl. J. Med. 287:367, 1972. 4. Ungerleider, R. S., F. R. Appelbaum, R. J. Trapani, and A. B. Deisseroth: Lack of predictive value of antileukocyte antibody screening in granulocyte transfusion therapy. Blood 5O:(Supp1.)311, 1977(abstract).
Blood Freezing and Thawing Workloads To the Editor: The paper "The Impact of Converting to an All Frozen Blood System in a Large Regional Blood Center" by R. A. Kahn,etul. (Transfusion 18, 304, 1978). gave sound basic assumptions for the conversion, but I found the practical model for work output unrealistic. On the basis of five years' experience with frozen red blood cells, we have established practical work loads for the average technologist. Considering the time for paper work, fifty units frozen per technologist is a reasonable output in a seven and one-half hour shift. An increased workload almost always results in poor performance as is shown by low in vitro red blood cell recoveries. Washing outputs vary with technologists but one person can thaw and wash approximately five units per hour operating four semiautomated machines (two Haemonetics, Model 102; two IBM, Model 2991). In an average shift, the maximum washing output becomes thirty-eight units instead of the sixty the authors have proposed. An added machine would increase this number only slightly. Without doubt, twenty-five to thirty units per technician yields optimal quality and few or no mistakes in the paper work. -Ronuld Hoiberg. M . S . , MT (ASCP). Supervisor, Component Luborutory, Blood Bunk. Cook County Hospitul, Chicugo. IL 60612. The Foregoing Letter wus Submitted for Comment to Dr. Kahn Who Replied us Follows:
To the Editor: I am not surprised to learn that the actual work output experienced over a number of years is different from what we formulated in our time studies. There is no substitute for experience, and Cook County Hospital has led the way in institutions that have converted to an all-frozen blood system. Unfortunately, the output figures Mr. Hoiberg described make the economic picture bleak. One would need more technologists than we specified to handle the workload, and this will cost more money. Consequently, the overall cost of an all-frozen blood system will be higher than
353
we anticipated.-Richard A. Kuhn, Ph.D., ScientiJc Director. Missouri-Illinois Regionul Red Cross Blood Services, St. Louis, MO 63108.
A Second Example of Anti-ILe"" To the Editor: A 63-year-old woman, type A, Le(a+b-), was found to have an antibody which reacted best against type 0 or AP. Le(a-b+) red blood cells from I-positive individuals. The antibody failed to react with Group 0, I, Le(a+b-) and Group A,, I, Le(a-b+) individuals. The antibody also failed to react with Group 0, i, Le(a-b+) red blood cells. Complete neutralization of the antibody was attained using commercially available Lewis substance. Tegoli et ul. described a similar antibody and we conclude this to be a second example.-Don Brunch, B.S., MT(ASCP) und Tom Powers, MT(ASCP). Immunohemutology Section, Queen of the Vulley Hospital. Nupu. CA. References 1.
Tegoli, J., M. Cortez, L. Jensen, and W. L. Marsh: Vox Sang. 21:397, 1971.
Statistical Effects of Varying Blood Life Span from 14 to 28 Days To the Editor: Mr. Pegels states in his article in the MarchApril 1978 issue of Transfusion that the "(21 days for blood stored in either solution) should be extended to 28 days for CPD blood as is presently being done in Canada." He cites a Bureau of Standards publication as the source of the information for the 28-day dating period. The exact wording ofthe cited Bureau of Standards publication is that "Canada allows 28 days storage in CPD." In 1972, the same 28-day dating period statement was made at a National Institutes of Health meeting to show how behind the times the United States regulatory agency was. However, when I contacted the Canadian Red Cross Blood Transfusion Service at thai time I was informed the dating period for Whole Blood and Red Cells was 21 days even though 28 days was allowed. On June 29, 1978, I received the following from the Canadian Red Cross: "On the 28 day outdating for Whole Blood and Red Blood Cells: At present we do not have any plans to extend the (current) 21 day, dating period." It appears that what is allowed and what is practiced are 7 days apart.-Robert M. Pennington. Assistunt Scientific Director, Blood Services, Americun Nutionul Red Cross, Wushington, DC.
CORRESPONDENCE
3. Graw, R. G., G. Herzig, S. Perry, and E. S. Henderson: Normal granulocyte transfusion therapy. Treatment of septicemia due to gram-negative bacteria. N. Engl. J. Med. 287:367, 1972. 4. Ungerleider, R. S., F. R. Appelbaum, R. J. Trapani, and A. B. Deisseroth: Lack of predictive value of antileukocyte antibody screening in granulocyte transfusion therapy. Blood 5O:(Supp1.)311, 1977(abstract).
Blood Freezing and Thawing Workloads To the Editor: The paper "The Impact of Converting to an All Frozen Blood System in a Large Regional Blood Center" by R. A. Kahn,etul. (Transfusion 18, 304, 1978). gave sound basic assumptions for the conversion, but I found the practical model for work output unrealistic. On the basis of five years' experience with frozen red blood cells, we have established practical work loads for the average technologist. Considering the time for paper work, fifty units frozen per technologist is a reasonable output in a seven and one-half hour shift. An increased workload almost always results in poor performance as is shown by low in vitro red blood cell recoveries. Washing outputs vary with technologists but one person can thaw and wash approximately five units per hour operating four semiautomated machines (two Haemonetics, Model 102; two IBM, Model 2991). In an average shift, the maximum washing output becomes thirty-eight units instead of the sixty the authors have proposed. An added machine would increase this number only slightly. Without doubt, twenty-five to thirty units per technician yields optimal quality and few or no mistakes in the paper work. -Ronuld Hoiberg. M . S . , MT (ASCP). Supervisor, Component Luborutory, Blood Bunk. Cook County Hospitul, Chicugo. IL 60612. The Foregoing Letter wus Submitted for Comment to Dr. Kahn Who Replied us Follows:
To the Editor: I am not surprised to learn that the actual work output experienced over a number of years is different from what we formulated in our time studies. There is no substitute for experience, and Cook County Hospital has led the way in institutions that have converted to an all-frozen blood system. Unfortunately, the output figures Mr. Hoiberg described make the economic picture bleak. One would need more technologists than we specified to handle the workload, and this will cost more money. Consequently, the overall cost of an all-frozen blood system will be higher than
353
we anticipated.-Richard A. Kuhn, Ph.D., ScientiJc Director. Missouri-Illinois Regionul Red Cross Blood Services, St. Louis, MO 63108.
A Second Example of Anti-ILe"" To the Editor: A 63-year-old woman, type A, Le(a+b-), was found to have an antibody which reacted best against type 0 or AP. Le(a-b+) red blood cells from I-positive individuals. The antibody failed to react with Group 0, I, Le(a+b-) and Group A,, I, Le(a-b+) individuals. The antibody also failed to react with Group 0, i, Le(a-b+) red blood cells. Complete neutralization of the antibody was attained using commercially available Lewis substance. Tegoli et ul. described a similar antibody and we conclude this to be a second example.-Don Brunch, B.S., MT(ASCP) und Tom Powers, MT(ASCP). Immunohemutology Section, Queen of the Vulley Hospital. Nupu. CA. References 1.
Tegoli, J., M. Cortez, L. Jensen, and W. L. Marsh: Vox Sang. 21:397, 1971.
Statistical Effects of Varying Blood Life Span from 14 to 28 Days To the Editor: Mr. Pegels states in his article in the MarchApril 1978 issue of Transfusion that the "(21 days for blood stored in either solution) should be extended to 28 days for CPD blood as is presently being done in Canada." He cites a Bureau of Standards publication as the source of the information for the 28-day dating period. The exact wording ofthe cited Bureau of Standards publication is that "Canada allows 28 days storage in CPD." In 1972, the same 28-day dating period statement was made at a National Institutes of Health meeting to show how behind the times the United States regulatory agency was. However, when I contacted the Canadian Red Cross Blood Transfusion Service at thai time I was informed the dating period for Whole Blood and Red Cells was 21 days even though 28 days was allowed. On June 29, 1978, I received the following from the Canadian Red Cross: "On the 28 day outdating for Whole Blood and Red Blood Cells: At present we do not have any plans to extend the (current) 21 day, dating period." It appears that what is allowed and what is practiced are 7 days apart.-Robert M. Pennington. Assistunt Scientific Director, Blood Services, Americun Nutionul Red Cross, Wushington, DC.
