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MINIMUM HÆMOGLOBIN LEVELS FOR WOMEN BLOOD-DONORS
361 arrived in Abbots Bromley to build the tower onto the old church. Tradition says they fathered some of the local children and to this day some outsiders still comment, perhaps unscientifically, on the Italian appearance of some
villagers. Perhaps the abnormal haemoglobins are due to this local, temporary immigration, and it would be interesting
of the
if local historians know of similar parts of the country. Cheltenham General Hospital, Cheltenham, Glos. GL53 7AN.
occurrences
in other
T. P. ORMEROD.
SIR,—My attention has been drawn to a misprint in your on iron supplements for blood-donors (May 24, p. 1174). For the past 25 years the generally observed acceptable minimum haemoglobin level for women donors in the United Kingdom has been 12-5 g/dl not 11 -5 g/dl. annotation
Lister Institute of Preventive
WD6 3AX.
W. D’A. MAYCOCK, Head, Blood Products Laboratory.
PREVENTION OF POSTOPERATIVE THROMBOEMBOLISM
SIR,—I congratulate all participants who were involved organising and completing the massive multicentre trial (July 12, p. 45). For me it is extremely gratifying to see
in
confirmation of what my limited studies had predicted ’— namely, that fatal pulmonary thromboembolism in the operative patient is preventable by heparin prophylaxis. I should like to offer a few observations from my own " small dose " subcutaneous schedule which I have administered now for the past fifteen years and which I find will offer better results than those obtained in the trial. In my ongoing programme I have been administering 10 000 units of aqueous sodium heparin subcutaneously at midnight before elective surgery and 2500 units every six hours following surgery until full reactivation or discharge, monitored by the modified Dale and Laidlaw coagulometer. The initial dose by assay, following a rise to hypocoagulable blood levels at two to three hours, gives normocoagulable levels eight to ten hours later at the time of surgery. The " low dose " schedule on the other hand, calling for 5000 units of calcium heparin subcutaneously two hours before surgery, means that surgery is being performed " at the peak of heparin effect" 2-namely, at hypocoagulable levels. This may well explain the hmmorrhages and significant hamiatomas observed in the trial. Another likely explanation for the hsematomas is that the " low dose " schedule required " no laboratory control to regulate dosage 11.2This is generally true, but my experience with the modified Dale and Laidlaw coagulometer has shown that there is enough variation, as well as errors of omission and commission, requiring adjustments in dosage of heparin to make laboratory monitoring imperative. I find it essential to good control. And the modified Dale and Laidlaw coagulometer is extremely simple and reliable. A further suggestion is that postoperative heparin be continued until the patient is fully reactivated or discharged. This is to protect the patient prophylactically for another critical hypercoagulable period, following days of immobilisation-namely, the time of remobilisation. 1. 2.
begin heparin prophylaxis immediately upon hospital admission, administering 2500 units subcutaneously every six hours and then changing to the above described preoperative and postoperative schedule, all monitored with the coagulometer daily, has given equally good results as with other major surgery. The preoperative schedule is used in this material to cover the period of complete immobilisation before surgery, however long it may last. Our review disclosed a total of 836 instances of hip surgery almost equally divided into adequately heparinised and not-preheparinised or inadequately heparinised hip fractures pinned or given prostheses. The adequately heparinised had a 0.5% incidence of fatal thromboembolism, whereas the not-heparinised or inadequately heparinised had an incidence of 3-5%. More recently in a consecutive series of 130 hip pinnings, with the above-mentioned preoperative
to
MINIMUM HÆMOGLOBIN LEVELS FOR WOMEN BLOOD-DONORS
Medicine, Elstree, Hertfordshire
I note that acute fractures were excluded from the trial. This is unfortunate since the elderly with hip fractures requiring open reduction have the greatest incidence of fatal thromboembolism. This exclusion was no doubt " prompted by the reports of others 3-5 indicating that low dose" heparin prophylaxis " did not lend itself " to this type of surgery. A review of our own results with these " cases using the small dose " schedule, merely altering it
Sharnoff, J. G., DeBlasio, G. Lancet, 1970, ii, 1006. Kakkar, V. V., Field, E. S., Nicolaides, A. N., Flute, P. T., Wessler, S., Yin, E. T. ibid. 1971, ii, 669.
" small dose " schedule, no fatal embolisms have been observed. No serious haemorrhages or wound hasmatomas were noted in the heparinised patients. As a pathologist, I find it difficult to accept the conclusions drawn by twenty-eight different pathologists who interpreted how large the thromboemboli were that could be judged to cause death. All of us are satisfied to conclude that microscopic findings of fat emboli in bone fractures are a cause of death, but most are still unwilling to accept multiple small pulmonary thromboemboli as adequate. This is one weakness of the trial report which may seriously affect the statistics. Nevertheless, I agree that the trial has shown that there is a means of saving many thousands of lives, and surgeons should be urged to "adopt heparin, prophylaxis whether it be low dose " or small dose ". "
Mount Vernon Hospital, Mount Vernon, New York 10550, U.S.A.
J. GEORGE SHARNOFF.
ALFALFA AND BLOOD-CHOLESTEROL
SIR,—Burkitt and others 6,7 suggest that many of the diseases of Western civilisation, including coronary-artery disease, may be related to the increased consumption of refined foodstuffs and the consequent reduction of dietary fibre. With respect to coronary-artery disease, the protective action of fibre is thought to reside in its ability to increase the excretion of neutral sterols and bile acids and thereby to lower blood and tissue lipid levels. Some years ago Altschul noted that rabbits maintained on alfalfa habitually had low blood-cholesterol levels. Cookson and Fedoroff showed that the blood-cholesterol levels in these rabbits remained low even in the face of very large doses of dietary cholesterol. 8,9 We carried out a study 10 of sterol excretion in the alfalfa fed rabbit which 3.
Gallus, A. S., Hirsh, J., Tuggle, R. J., Trebilcock, R., O’Brien, S. E. Carroll, J. J., Menden, J. H., Hudecki, S. M. New Engl. J. Med. 1973, 228, 545. 4. Charnley, J. Lancet, 1972, ii, 134. 5. Harris, W. H., Salzman, E. W., Athanasaulis, C., Waltman, A. C., Baum, S., DeSanctis, R. N. J. Bone Joint Surg. 1974, 56A, 1552. 6. Burkitt, D. P. Br. med. J. 1973, i, 274. 7. Burkitt, D. P., Walker, A. R. P., Painter, N. S. J. Am. med. Ass. 1974, 229, 1068. 8. Cookson, F. B., Altschul, R., Fedoroff, S. J. Atheroscler. Res. 1967, 7, 69. 9. Cookson, F. B., Fedoroff, S. Br. J. exp. Path. 1968, 44, 348.
10. Horlick, L., Cookson, F. B., Fedoroff, S. Circulation, 1967, 35-36, II—18.
villagers. Perhaps the abnormal haemoglobins are due to this local, temporary immigration, and it would be interesting
of the
if local historians know of similar parts of the country. Cheltenham General Hospital, Cheltenham, Glos. GL53 7AN.
occurrences
in other
T. P. ORMEROD.
SIR,—My attention has been drawn to a misprint in your on iron supplements for blood-donors (May 24, p. 1174). For the past 25 years the generally observed acceptable minimum haemoglobin level for women donors in the United Kingdom has been 12-5 g/dl not 11 -5 g/dl. annotation
Lister Institute of Preventive
WD6 3AX.
W. D’A. MAYCOCK, Head, Blood Products Laboratory.
PREVENTION OF POSTOPERATIVE THROMBOEMBOLISM
SIR,—I congratulate all participants who were involved organising and completing the massive multicentre trial (July 12, p. 45). For me it is extremely gratifying to see
in
confirmation of what my limited studies had predicted ’— namely, that fatal pulmonary thromboembolism in the operative patient is preventable by heparin prophylaxis. I should like to offer a few observations from my own " small dose " subcutaneous schedule which I have administered now for the past fifteen years and which I find will offer better results than those obtained in the trial. In my ongoing programme I have been administering 10 000 units of aqueous sodium heparin subcutaneously at midnight before elective surgery and 2500 units every six hours following surgery until full reactivation or discharge, monitored by the modified Dale and Laidlaw coagulometer. The initial dose by assay, following a rise to hypocoagulable blood levels at two to three hours, gives normocoagulable levels eight to ten hours later at the time of surgery. The " low dose " schedule on the other hand, calling for 5000 units of calcium heparin subcutaneously two hours before surgery, means that surgery is being performed " at the peak of heparin effect" 2-namely, at hypocoagulable levels. This may well explain the hmmorrhages and significant hamiatomas observed in the trial. Another likely explanation for the hsematomas is that the " low dose " schedule required " no laboratory control to regulate dosage 11.2This is generally true, but my experience with the modified Dale and Laidlaw coagulometer has shown that there is enough variation, as well as errors of omission and commission, requiring adjustments in dosage of heparin to make laboratory monitoring imperative. I find it essential to good control. And the modified Dale and Laidlaw coagulometer is extremely simple and reliable. A further suggestion is that postoperative heparin be continued until the patient is fully reactivated or discharged. This is to protect the patient prophylactically for another critical hypercoagulable period, following days of immobilisation-namely, the time of remobilisation. 1. 2.
begin heparin prophylaxis immediately upon hospital admission, administering 2500 units subcutaneously every six hours and then changing to the above described preoperative and postoperative schedule, all monitored with the coagulometer daily, has given equally good results as with other major surgery. The preoperative schedule is used in this material to cover the period of complete immobilisation before surgery, however long it may last. Our review disclosed a total of 836 instances of hip surgery almost equally divided into adequately heparinised and not-preheparinised or inadequately heparinised hip fractures pinned or given prostheses. The adequately heparinised had a 0.5% incidence of fatal thromboembolism, whereas the not-heparinised or inadequately heparinised had an incidence of 3-5%. More recently in a consecutive series of 130 hip pinnings, with the above-mentioned preoperative
to
MINIMUM HÆMOGLOBIN LEVELS FOR WOMEN BLOOD-DONORS
Medicine, Elstree, Hertfordshire
I note that acute fractures were excluded from the trial. This is unfortunate since the elderly with hip fractures requiring open reduction have the greatest incidence of fatal thromboembolism. This exclusion was no doubt " prompted by the reports of others 3-5 indicating that low dose" heparin prophylaxis " did not lend itself " to this type of surgery. A review of our own results with these " cases using the small dose " schedule, merely altering it
Sharnoff, J. G., DeBlasio, G. Lancet, 1970, ii, 1006. Kakkar, V. V., Field, E. S., Nicolaides, A. N., Flute, P. T., Wessler, S., Yin, E. T. ibid. 1971, ii, 669.
" small dose " schedule, no fatal embolisms have been observed. No serious haemorrhages or wound hasmatomas were noted in the heparinised patients. As a pathologist, I find it difficult to accept the conclusions drawn by twenty-eight different pathologists who interpreted how large the thromboemboli were that could be judged to cause death. All of us are satisfied to conclude that microscopic findings of fat emboli in bone fractures are a cause of death, but most are still unwilling to accept multiple small pulmonary thromboemboli as adequate. This is one weakness of the trial report which may seriously affect the statistics. Nevertheless, I agree that the trial has shown that there is a means of saving many thousands of lives, and surgeons should be urged to "adopt heparin, prophylaxis whether it be low dose " or small dose ". "
Mount Vernon Hospital, Mount Vernon, New York 10550, U.S.A.
J. GEORGE SHARNOFF.
ALFALFA AND BLOOD-CHOLESTEROL
SIR,—Burkitt and others 6,7 suggest that many of the diseases of Western civilisation, including coronary-artery disease, may be related to the increased consumption of refined foodstuffs and the consequent reduction of dietary fibre. With respect to coronary-artery disease, the protective action of fibre is thought to reside in its ability to increase the excretion of neutral sterols and bile acids and thereby to lower blood and tissue lipid levels. Some years ago Altschul noted that rabbits maintained on alfalfa habitually had low blood-cholesterol levels. Cookson and Fedoroff showed that the blood-cholesterol levels in these rabbits remained low even in the face of very large doses of dietary cholesterol. 8,9 We carried out a study 10 of sterol excretion in the alfalfa fed rabbit which 3.
Gallus, A. S., Hirsh, J., Tuggle, R. J., Trebilcock, R., O’Brien, S. E. Carroll, J. J., Menden, J. H., Hudecki, S. M. New Engl. J. Med. 1973, 228, 545. 4. Charnley, J. Lancet, 1972, ii, 134. 5. Harris, W. H., Salzman, E. W., Athanasaulis, C., Waltman, A. C., Baum, S., DeSanctis, R. N. J. Bone Joint Surg. 1974, 56A, 1552. 6. Burkitt, D. P. Br. med. J. 1973, i, 274. 7. Burkitt, D. P., Walker, A. R. P., Painter, N. S. J. Am. med. Ass. 1974, 229, 1068. 8. Cookson, F. B., Altschul, R., Fedoroff, S. J. Atheroscler. Res. 1967, 7, 69. 9. Cookson, F. B., Fedoroff, S. Br. J. exp. Path. 1968, 44, 348.
10. Horlick, L., Cookson, F. B., Fedoroff, S. Circulation, 1967, 35-36, II—18.