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PREPARATION OF BLOOD-FILMS IN SUSPECTED MALARIA
499
PREPARATION OF BLOOD-FILMS IN SUSPECTED MALARIA
SIR,-In your issue of July 10 (p. 97) reference was made to the large number of ca,ses of malaria which have been reported in this country during recent years, chiefly among members of H.M. Forces returning from Korea, Hong-Kong, and Malaya. General practitioners were warned that such cases might act as foci for outbreaks of indigenous malaria, and stress was laid on the importance of making blood-films from all suspected cases.
The following notes on the films may be found helpful.
technique for preparing such
Slides If possible, these should be new ones. Scratched or foggy slides should never be used. Before making blood-films, the slides should be taken through an ether alcohol solution, equal parts, and wiped with a clean, dry cloth. Unll1ss the slides are quite free from grease, thin blood-films will not spread evenly and thick drops will peel off during the process of staining. This Films After cleaning the pad of the finger or lobe of the ear, the skin should be wiped dry. Puncture the skin with a straight triangular surgical needle and wipe off the first drop of blood. A bead of blood for a thin film should be no larger than the head of a pin. If a slide is used for spreading a film. see that it is a thin one and has a smooth edge. Contact of the slide with the bead of blood should be at an angle of 45 and the film should be made by pushing away from the blood. The aim in making a thin film should be to have the corpuscles only one deep ; the cells should almost touch one another but not overlap. Good thin films cannot be made if a thick slide is used for spreading the film or if the drop of blood is too
large.
Thick Films A large drop of blood is placed in the centre of a clean slide and then distributed in a circular movement with the edge of another slide. The correct thickness of a thick film can be determined in the following way. After distributing the blood, place the slide over a piece of newspaper or over the face of a watch. The small print or the hands of a watch should only just be visible. If these cannot be seen the drop is too thick and if seen too clearly, it is too thin. After preparing a. thick film, lay it flat until it is quite dry. If flies are about, films should be covered with a Petri dish, otherwise the blood will be eaten by them.
Films, when quite dry, should be wrapped in tissue One thin and one thick paper and securely packed. film (unstained) should be sent, but preferably two of each. Blood-films, preferably unstained, may be sent to the Medical Research Council Malaria Reference Laboratory, Horton Hospital, Epsom, Surrey. P. G. SHUTE Malaria Reference Laboratory, Assistant Director. Epsom, Surrey. FINGER CLUBBING
SiR,-Dr. Pyke’s assessment, in his article of Aug. 21, of the
validity of finger clubbing as a physical sign is valuable additional evidence of invididual fallibility, and leads to similar conclusions to those drawn from comparisons of such things as the interpretation of
radiographs. There appears, however, to be a fallacy inherent in his material. He states that only 4 observers (the
students) used the nail-bed angle as their criterion, while all 12 doctors used other evidence. This seems to imply that the outline of the finger-tip was considered by them to be of some importance. Yet the method employed to photograph the fingers is very ill designed to reveal outline. The fingers are lit almost axially, thus leaving the edges of the outline in deep shadow, and they are placed against a dark, almost black, ground. In the half-tone reproductions at least, it is impossible to make out the outline. ’
I
suggeat
outline
that in
these
and
similar
cases, where
is
significant, the surface lighting is chosen appropriately to the subject, but the background is transiMuminated, so that the image has no external shadows whatever. The procedure is simple, calling only for an X-ray illuminator, and a few simple tests will indicate the correct light balance and exposure factors. The example in the accompanying photograph is of a rather gross case, but it indicates the accurate delineation of outline which is possible. The method, I would add, is well known to all experienced medical photographers. Department of Medical Illustration, Manchester Royal Infirmary.
ROBERT OLLERENSHAW.
HISTORY OF INGUINAL-HERNIA REPAIR
SiR,ŇReading one of your leading articles1 of 1951 encouraged me to write about several points in the
has
of inguinal-hernia repair about which there appears to be widespread confusion. These are : (1) the relaxation incision in the sheath of the rectus muscle ; (2) the operation utilising the rectus muscle itself to reinforce the Hesselbach triangle area (" pubic corner ") ; and (3) the use of a flap of the external sheath of the rectus to reinforce the same area. The relaxation incision in the sheath of the rectus muscle was, so far as I have been able to find out, first used by Halsted and was described by him in 1903.1 The relaxation occasioned by this incision - generally allows the conjoined tendon to be brought down to Poupart’s ligament without tension. The method was reported by Halsted in a moderately long article on inguinal-hernia repair, and -for this reason was probably overlooked by a great many subsequent workers in this field. Fallis,2 Rienhoff,3 and Tanner4 much later published what is very much the same method. I believe that in England the method is generally known as the " Tanner slide." Cases which often give a :great deal of trouble are those in which there is a paucity of tissues for closing the " critical angle " in the pubic corner at the lower end of the inguinal canal. The trouble here is often that there is either no conjoined tendon, or the conjoined tendon, instead of being attached to the spine of the pubis, is attached higher up to the linea semilunaris. This leaves a triangular area in which there is a tissue defect. In order to close the area in the usual fashion, poor structures would have to be sutured together under considerable tension. In order to obviate this, BloodgoodIi split the posterior border of the lateral edge of the sheath of the rectus and brought the muscle-fibres of the rectus muscle itself down to Poupart’s ligament, suturing them there and thus closing the area. W61fier6 had used a similar method before Bloodgood. Halsted7 states that Bloodgood knew nothing of Wolfler’s operation at the time he first used his own method, and that Wolner
history
,
1. 2. 3. 4. 5. 6. 7.
Halsted, W. S. Bull. Johns Hopk. Hosp. 1903, 14, 208. Fallis, L. S. Ann. Surg. 1938, 107, 572. Rienhoff, W. F. jun. Surgery, 1940, 8, 326. Tanner, N. C. Brit. J. Surg. 1942, 29, 285. Bloodgood, J. C. Johns Hopk. Hosp. Rep. 1899, 7, 232. Wölfler, A. Beitr. Chir. 1892, p. 552. Halsted, W. S. Surgical Papers. Baltimore, 1924 ; p. 306.
vol.
1.
PREPARATION OF BLOOD-FILMS IN SUSPECTED MALARIA
SIR,-In your issue of July 10 (p. 97) reference was made to the large number of ca,ses of malaria which have been reported in this country during recent years, chiefly among members of H.M. Forces returning from Korea, Hong-Kong, and Malaya. General practitioners were warned that such cases might act as foci for outbreaks of indigenous malaria, and stress was laid on the importance of making blood-films from all suspected cases.
The following notes on the films may be found helpful.
technique for preparing such
Slides If possible, these should be new ones. Scratched or foggy slides should never be used. Before making blood-films, the slides should be taken through an ether alcohol solution, equal parts, and wiped with a clean, dry cloth. Unll1ss the slides are quite free from grease, thin blood-films will not spread evenly and thick drops will peel off during the process of staining. This Films After cleaning the pad of the finger or lobe of the ear, the skin should be wiped dry. Puncture the skin with a straight triangular surgical needle and wipe off the first drop of blood. A bead of blood for a thin film should be no larger than the head of a pin. If a slide is used for spreading a film. see that it is a thin one and has a smooth edge. Contact of the slide with the bead of blood should be at an angle of 45 and the film should be made by pushing away from the blood. The aim in making a thin film should be to have the corpuscles only one deep ; the cells should almost touch one another but not overlap. Good thin films cannot be made if a thick slide is used for spreading the film or if the drop of blood is too
large.
Thick Films A large drop of blood is placed in the centre of a clean slide and then distributed in a circular movement with the edge of another slide. The correct thickness of a thick film can be determined in the following way. After distributing the blood, place the slide over a piece of newspaper or over the face of a watch. The small print or the hands of a watch should only just be visible. If these cannot be seen the drop is too thick and if seen too clearly, it is too thin. After preparing a. thick film, lay it flat until it is quite dry. If flies are about, films should be covered with a Petri dish, otherwise the blood will be eaten by them.
Films, when quite dry, should be wrapped in tissue One thin and one thick paper and securely packed. film (unstained) should be sent, but preferably two of each. Blood-films, preferably unstained, may be sent to the Medical Research Council Malaria Reference Laboratory, Horton Hospital, Epsom, Surrey. P. G. SHUTE Malaria Reference Laboratory, Assistant Director. Epsom, Surrey. FINGER CLUBBING
SiR,-Dr. Pyke’s assessment, in his article of Aug. 21, of the
validity of finger clubbing as a physical sign is valuable additional evidence of invididual fallibility, and leads to similar conclusions to those drawn from comparisons of such things as the interpretation of
radiographs. There appears, however, to be a fallacy inherent in his material. He states that only 4 observers (the
students) used the nail-bed angle as their criterion, while all 12 doctors used other evidence. This seems to imply that the outline of the finger-tip was considered by them to be of some importance. Yet the method employed to photograph the fingers is very ill designed to reveal outline. The fingers are lit almost axially, thus leaving the edges of the outline in deep shadow, and they are placed against a dark, almost black, ground. In the half-tone reproductions at least, it is impossible to make out the outline. ’
I
suggeat
outline
that in
these
and
similar
cases, where
is
significant, the surface lighting is chosen appropriately to the subject, but the background is transiMuminated, so that the image has no external shadows whatever. The procedure is simple, calling only for an X-ray illuminator, and a few simple tests will indicate the correct light balance and exposure factors. The example in the accompanying photograph is of a rather gross case, but it indicates the accurate delineation of outline which is possible. The method, I would add, is well known to all experienced medical photographers. Department of Medical Illustration, Manchester Royal Infirmary.
ROBERT OLLERENSHAW.
HISTORY OF INGUINAL-HERNIA REPAIR
SiR,ŇReading one of your leading articles1 of 1951 encouraged me to write about several points in the
has
of inguinal-hernia repair about which there appears to be widespread confusion. These are : (1) the relaxation incision in the sheath of the rectus muscle ; (2) the operation utilising the rectus muscle itself to reinforce the Hesselbach triangle area (" pubic corner ") ; and (3) the use of a flap of the external sheath of the rectus to reinforce the same area. The relaxation incision in the sheath of the rectus muscle was, so far as I have been able to find out, first used by Halsted and was described by him in 1903.1 The relaxation occasioned by this incision - generally allows the conjoined tendon to be brought down to Poupart’s ligament without tension. The method was reported by Halsted in a moderately long article on inguinal-hernia repair, and -for this reason was probably overlooked by a great many subsequent workers in this field. Fallis,2 Rienhoff,3 and Tanner4 much later published what is very much the same method. I believe that in England the method is generally known as the " Tanner slide." Cases which often give a :great deal of trouble are those in which there is a paucity of tissues for closing the " critical angle " in the pubic corner at the lower end of the inguinal canal. The trouble here is often that there is either no conjoined tendon, or the conjoined tendon, instead of being attached to the spine of the pubis, is attached higher up to the linea semilunaris. This leaves a triangular area in which there is a tissue defect. In order to close the area in the usual fashion, poor structures would have to be sutured together under considerable tension. In order to obviate this, BloodgoodIi split the posterior border of the lateral edge of the sheath of the rectus and brought the muscle-fibres of the rectus muscle itself down to Poupart’s ligament, suturing them there and thus closing the area. W61fier6 had used a similar method before Bloodgood. Halsted7 states that Bloodgood knew nothing of Wolfler’s operation at the time he first used his own method, and that Wolner
history
,
1. 2. 3. 4. 5. 6. 7.
Halsted, W. S. Bull. Johns Hopk. Hosp. 1903, 14, 208. Fallis, L. S. Ann. Surg. 1938, 107, 572. Rienhoff, W. F. jun. Surgery, 1940, 8, 326. Tanner, N. C. Brit. J. Surg. 1942, 29, 285. Bloodgood, J. C. Johns Hopk. Hosp. Rep. 1899, 7, 232. Wölfler, A. Beitr. Chir. 1892, p. 552. Halsted, W. S. Surgical Papers. Baltimore, 1924 ; p. 306.
vol.
1.