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THE SIGNIFICANCE OF EOSINOPHIL-COUNTS
1170
Letters to the Editor
DANGERS SiB,—I should
OF THE MUCUS CATHETER like to draw attention to some dangers
associated with the mucus catheter so frequently used on the newborn infant. The mucus catheter, if correctly used, should be a safe instrument for removing mucus and other secretions from the upper air passages of the asphyxiated baby. The ;catheter lies ready sterilised in a covered dish during delivery so- as to be available for immediate use if necessary. It is -sterile on the first occasion it is inserted into the baby’s mouth, but is by no means so
subsequent insertions. Many a timehave seen a catheter allowed over unsterile bedsheets, blankets, and towels on
to trail that after the initial sterile insertion a large number of organisms are introduced by the instrument into the baby’s upper respiratory passages and pharynx. Moreover, the catheter is frequently passed much too far down and in some cases would appear to reach into the oesophagus-surely not only a useless but also a dangerous procedure. This direct implantation of organisms may result in virulent pneumonia or gastro-enteritis ; recently I have seen some seriously ill babies with these infections in whom the source of infection was in all probability the mucus catheter. I feel that teachers of medical students and midwives out these risks and should impress upon should them : I
so
point
the mucus catheter as a routine measure (a procedure I have noted in many hospitals and nursinghomes). It should be used only if the mucus cannot be removed by posture or the baby’s own efforts. 2. Not to pass the catheter further than the pharynx. (It might be worth while putting a mark on the catheter 2 in. from the tip so that it cannot be passed too far). 3. To wipe the end of the catheter, after each insertion, on some sterile material. 4. To avoid contamination of the catheter with unsterile objects, and to lay it on a sterile towel during use. 1. Not to
M. E. LANDAU.
EOSINOPHIL-COUNTS of June 3 has done a great SiR,-Your leading article service in drawing attention to the use and difficulties of eosinophil-counts. There are some points of importance, however, which I feel ought not to be passed without comment. In the first place, Fin Rud’s1 extensive work is rightly quoted, but his results are accepted quite uncritically. Like Thorn and Forsham in Boston and Prunty in this country, he uses a modification of Dunger’s technique for the direct counting of eosinophils. However, as pointed out by Randolph,2 the solution used lyses not only the red cells but also the white. As anyone who has used this technique will realise, one must not shake the pipette containing the blood and dilution fluid for more than about 30 seconds before transferring the contents to the counting chamber. If very much longer than this is taken for mixing, no eosinophils can be found, and it is doubtful whether adequate mixing can be obtained in this short time. Certainly in my hands this method of counting not infrequently has yielded results which were obviously erroneous. A further point of criticism is that Rud counts only the cells in one Fuchs-Rosenthal chamber, whereas it is quite possible to fill eight such chambers from one white-cell pipette, thereby increasing one’s accuracy nearly threefold. Dr. Janet MacArthur, Dr. Donald Harting, and myself, working at the Massachusetts General Hospital, have SIGNIFICANCE
1. Rud, F.
cells occurs, that the total white-cell count can be dpne in the same chamber as the eosinophil-count, and that the mixture of blood and dilution fluid can remain for a considerable time in the white blood-cell pipette
without detriment. Using this technique, and counting the cells in eight chambers, a spontaneous fall in the eosinophils of a normal person of the degree quoted by you may occur between 10 A.M. and 2 P.M., even if that person is kept under basal conditions, but I should be very surprised if it did so In any event, using this counting very commonly. four-hour the adrenocorticotropic-hormone technique, (A.C.T.H.) test described by Forsham and his colleaguesa has been found to give quite reliable results in clinical practice, there being even some relationship between the eosinophil fall and the clinical response of an arthritic
patient to A.C.T.H. Finally, may I use this opportunity to deprecate the use of such expressions as " 40 to 228 per c.mm. should be regarded as the normal range for males... " Until there is a generally agreed convention as to what consti. tutes a " normal range," such expressions are quite devoid of that precision of meaning which one usually associates with scientific terminology. Department
The
OF
Eosinophil-Count
in Health and Mental Disease.
Oslo, 1947. 2. Randolph, T. G. J. Allergy, 1944, 15, 89.
of
Medicine,
G. A. SMART.
University of Bristol.
CIRCULATORY CHANGES AFTER SYMPATHECTOMY
use
London, N.W.2. THE
modified the .technique described by Randolph,2 using propylene glycol to render the red blood.corpusc1E1S invisible. The details of this method wjtil be published elsewhere, but the advantages are that no lysis of any
was greatly interested in last week’s articles Mr. Lynn and Professor Barcroft, and by Mr. Lynn and Mr. Martin. I suggest that in all the cases described the effects are due chiefly to the direct transference of arterial blood to the veins as the result of the openirig up of the arteriovenous communications which occurs after sympathectomy. Modern textbooks of physiology have paid insufficient attention to the work of Claude Bernard4 own the effects of cervical sympathectomy. This great French physiologist wrote :
SIR,-I
by
"... quand on a preablementcoupe le grand la circulasympathique dans la region moyenne du cou tion s’accelere considerablement, la temperature augmente, le sang veineux devient rouge, la pression augmente. Si l’on vient à galvaniser le bout peripherique ou superieur du sympathique, la circulation diminue d’intensite, les vaisseaux se resserent, et la temperature baisse en même ...
temps que le sang devient tres noir. les chevaux ou tous grande evidence." sur
ces
faits
C’est particulièrement se
presentent
avec une
It is probable that corresponding effects are produced in the vessels (and blood) of the limbs when their sympathetic nerves are similarly affected. Sucquet5 quoted Claude Bernard in his own classical monographs on arteriovenous communications-subsequently known as Sucquet-Hoyer canals 6-and offered reasonable data to indicate that these become opened up in conditionsof cachexia and after a rapid and prolonged phlebotomy. Sucquet found that after injecting fluid into the arteries of the limbs of the cadaver, the fluid reached the corresponding veins at rates which would not allow for its passage through capillaries. In the case of the lower limb, " il revient plus vite et plus abondamment par la veine crurale que par la saphene "suggesting even greater numbers of these communications in deep than in superficial vessels. Popoff,who examined 3. Forsham, P. G., Thorn, G. W., Prunty, F. G. T., Hills, A. G. J. clin. Endocrinol. 1948, 8, 15. 4. Bernard, M. C. Liquides de L’Organisme. Paris, 1859; vol 2, p. 436. 5. Sucquet, J. P. D’une circulation dans les membres et dans la tête chez l’homme. Paris, 1860 ; Ibid, 1862. 6. Hoyer, H. Arch. Mikr. Anat. 1877, 3, 603. 7. Popoff, N. W. Arch. Path. 1934, 18, 293.
Letters to the Editor
DANGERS SiB,—I should
OF THE MUCUS CATHETER like to draw attention to some dangers
associated with the mucus catheter so frequently used on the newborn infant. The mucus catheter, if correctly used, should be a safe instrument for removing mucus and other secretions from the upper air passages of the asphyxiated baby. The ;catheter lies ready sterilised in a covered dish during delivery so- as to be available for immediate use if necessary. It is -sterile on the first occasion it is inserted into the baby’s mouth, but is by no means so
subsequent insertions. Many a timehave seen a catheter allowed over unsterile bedsheets, blankets, and towels on
to trail that after the initial sterile insertion a large number of organisms are introduced by the instrument into the baby’s upper respiratory passages and pharynx. Moreover, the catheter is frequently passed much too far down and in some cases would appear to reach into the oesophagus-surely not only a useless but also a dangerous procedure. This direct implantation of organisms may result in virulent pneumonia or gastro-enteritis ; recently I have seen some seriously ill babies with these infections in whom the source of infection was in all probability the mucus catheter. I feel that teachers of medical students and midwives out these risks and should impress upon should them : I
so
point
the mucus catheter as a routine measure (a procedure I have noted in many hospitals and nursinghomes). It should be used only if the mucus cannot be removed by posture or the baby’s own efforts. 2. Not to pass the catheter further than the pharynx. (It might be worth while putting a mark on the catheter 2 in. from the tip so that it cannot be passed too far). 3. To wipe the end of the catheter, after each insertion, on some sterile material. 4. To avoid contamination of the catheter with unsterile objects, and to lay it on a sterile towel during use. 1. Not to
M. E. LANDAU.
EOSINOPHIL-COUNTS of June 3 has done a great SiR,-Your leading article service in drawing attention to the use and difficulties of eosinophil-counts. There are some points of importance, however, which I feel ought not to be passed without comment. In the first place, Fin Rud’s1 extensive work is rightly quoted, but his results are accepted quite uncritically. Like Thorn and Forsham in Boston and Prunty in this country, he uses a modification of Dunger’s technique for the direct counting of eosinophils. However, as pointed out by Randolph,2 the solution used lyses not only the red cells but also the white. As anyone who has used this technique will realise, one must not shake the pipette containing the blood and dilution fluid for more than about 30 seconds before transferring the contents to the counting chamber. If very much longer than this is taken for mixing, no eosinophils can be found, and it is doubtful whether adequate mixing can be obtained in this short time. Certainly in my hands this method of counting not infrequently has yielded results which were obviously erroneous. A further point of criticism is that Rud counts only the cells in one Fuchs-Rosenthal chamber, whereas it is quite possible to fill eight such chambers from one white-cell pipette, thereby increasing one’s accuracy nearly threefold. Dr. Janet MacArthur, Dr. Donald Harting, and myself, working at the Massachusetts General Hospital, have SIGNIFICANCE
1. Rud, F.
cells occurs, that the total white-cell count can be dpne in the same chamber as the eosinophil-count, and that the mixture of blood and dilution fluid can remain for a considerable time in the white blood-cell pipette
without detriment. Using this technique, and counting the cells in eight chambers, a spontaneous fall in the eosinophils of a normal person of the degree quoted by you may occur between 10 A.M. and 2 P.M., even if that person is kept under basal conditions, but I should be very surprised if it did so In any event, using this counting very commonly. four-hour the adrenocorticotropic-hormone technique, (A.C.T.H.) test described by Forsham and his colleaguesa has been found to give quite reliable results in clinical practice, there being even some relationship between the eosinophil fall and the clinical response of an arthritic
patient to A.C.T.H. Finally, may I use this opportunity to deprecate the use of such expressions as " 40 to 228 per c.mm. should be regarded as the normal range for males... " Until there is a generally agreed convention as to what consti. tutes a " normal range," such expressions are quite devoid of that precision of meaning which one usually associates with scientific terminology. Department
The
OF
Eosinophil-Count
in Health and Mental Disease.
Oslo, 1947. 2. Randolph, T. G. J. Allergy, 1944, 15, 89.
of
Medicine,
G. A. SMART.
University of Bristol.
CIRCULATORY CHANGES AFTER SYMPATHECTOMY
use
London, N.W.2. THE
modified the .technique described by Randolph,2 using propylene glycol to render the red blood.corpusc1E1S invisible. The details of this method wjtil be published elsewhere, but the advantages are that no lysis of any
was greatly interested in last week’s articles Mr. Lynn and Professor Barcroft, and by Mr. Lynn and Mr. Martin. I suggest that in all the cases described the effects are due chiefly to the direct transference of arterial blood to the veins as the result of the openirig up of the arteriovenous communications which occurs after sympathectomy. Modern textbooks of physiology have paid insufficient attention to the work of Claude Bernard4 own the effects of cervical sympathectomy. This great French physiologist wrote :
SIR,-I
by
"... quand on a preablementcoupe le grand la circulasympathique dans la region moyenne du cou tion s’accelere considerablement, la temperature augmente, le sang veineux devient rouge, la pression augmente. Si l’on vient à galvaniser le bout peripherique ou superieur du sympathique, la circulation diminue d’intensite, les vaisseaux se resserent, et la temperature baisse en même ...
temps que le sang devient tres noir. les chevaux ou tous grande evidence." sur
ces
faits
C’est particulièrement se
presentent
avec une
It is probable that corresponding effects are produced in the vessels (and blood) of the limbs when their sympathetic nerves are similarly affected. Sucquet5 quoted Claude Bernard in his own classical monographs on arteriovenous communications-subsequently known as Sucquet-Hoyer canals 6-and offered reasonable data to indicate that these become opened up in conditionsof cachexia and after a rapid and prolonged phlebotomy. Sucquet found that after injecting fluid into the arteries of the limbs of the cadaver, the fluid reached the corresponding veins at rates which would not allow for its passage through capillaries. In the case of the lower limb, " il revient plus vite et plus abondamment par la veine crurale que par la saphene "suggesting even greater numbers of these communications in deep than in superficial vessels. Popoff,who examined 3. Forsham, P. G., Thorn, G. W., Prunty, F. G. T., Hills, A. G. J. clin. Endocrinol. 1948, 8, 15. 4. Bernard, M. C. Liquides de L’Organisme. Paris, 1859; vol 2, p. 436. 5. Sucquet, J. P. D’une circulation dans les membres et dans la tête chez l’homme. Paris, 1860 ; Ibid, 1862. 6. Hoyer, H. Arch. Mikr. Anat. 1877, 3, 603. 7. Popoff, N. W. Arch. Path. 1934, 18, 293.