318 Letters Vol. 13 No. 6June 1997

Noboru Taguchi, MD Teruhiko Ishikawa, MD Jiro Sato, MD Takashi Nishino, MD Department of Anesthesiology School of Medicine, Chiba University Chiba, Japan

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References 1. Taguchi, Ishikawa T, Sato J, Nishino T. Effects

of induced metabolic alkalosis on perception of dys- pnea during flow-resistive loading. J Pain Symptom Manage 1996;12:11-17.

2. Singer RB, Deering RC, Clark JK. The acute effects in man of a rapid intravenous infnsion of hyper ton ic sod ium b ica rbona te solut ion. II. Changes in respiration and output of carbon diox- ide. J Clin Invest 1956;34:245-253.

3. Nishino T, Hata N, Sakakibara Y, Honda Y. Effect of the acute administration of sodium bica,- bonate on respiration in the presence of hyperoxia. BrJ Anaesth 1977; 49:331-339.

4. Goldring levi, Cannon PJ, Heinemann HO, Fish- man AP. Respiratory adjustment to chronic metabolic alkalosis in man. J Clin Invest 1968:188-202.

2 , 3 - d i p h o s p h o g l y c e r a t e (2,3-DPG) in trans- fused erythrocytes.

The c o n c e n t r a t i o n o f 2,3-DPG falls when b lood is s tored bu t rises again w h e n the b lood is transfused. It can take up to 72 hours , how- ever, for the levels o f 2,3-DPG in erythrocytes to r e tu rn to normal . 3 2,3-DPG affects the affin- ity o f h e m o g l o b i n for oxygen, 4 and a reduc- t ion in the concen t r a t ion can lead to a reduc- t ion in the release o f oxygen to the tissues. This fall, and subsequen t gradual rise, in the level o f 2 ,3-DPG may expla in the dispari ty between the results o f the two studies.

We agree with Mont i et al. t ha t f u r t h e r research needs to be d o n e in this area, and we would suggest that any future studies employ serial , r a t h e r t h a n s ingle , a s se s smen t s o f patients.

Andrew Davies, MBBS, MRCP Stephen Wang, MBBS, DCH St. Christopher's Hospice London, United Kingdom

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Blood Transfusions in Patients With Advanced Cancer

To the Editor: In a recent ly publ i shed study, Mont i et al. 1

f o u n d that only 51% o f their patients r epo r t ed an i m p r o v e m e n t in well-being the day after a b l o o d t r ans fus ion . G l e e s o n a n d S p e n c e r ~, however, f o u n d tha t 76% o f the i r pa t ien ts r epor t ed feel ing be t te r 2 days after a b lood transfusion. The reason for this disparity may be the t iming o f the assessment in the two studies. It also may be re la ted to the levels o f

R e f e r e n c e s

1. Monti M, Castellani L, Berlnsconi A, Cunietti E. Use of red blood cell transfusions in terminally ill cancer patients admitted to a palliative care unit. J Pain Symptom Manage 1996;12:18-22.

2. Gleeson C, Spencer D. Blood transfusion and its benefits in palliative care. Palliat Med 1995;9: 307-313.

3. Heaton A, Keegan T, Holme S. In vivo regen- eration of red cell 2,3-diphosphoglycerate following transfusion of DPC~depleted AS-I, AS-3 and CPDA-1 cells. BrJ Haematol 1989;71:131-136.

4. Ganong W. Review of medical physiology, 15th ed. Norwalk, CT: Appleton and Lange, 1991.