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DANGER OF AIR EMBOLISM IN HIGH-PRESSURE BLOOD-TRANSFUSIONS
429
catecholamines
are
produced selectively by malignant
tumours, but evidence against this has recently been shown (Kennedy et al. 1961). The site of origin of this tumour remains in doubt; it probably was the organ of Zuckerkandl, butthe tumour could have originated from any of the paraganglia related to the autonomic nerves in that region. In contrast to the case described by Farley and Smith (1959), which is the only other one known to us that presented with a nonfunctioning kidney, the tumour did not arise from the bladder. Cook et al. (1960) describe 3 cases of phaeochromocytomata of the organ of Zuckerkandl and review 3 others. They noted abdominal symptoms as being the rule in such cases, ascribing them to compression of
surrounding structures. Summary
12-year-old girl complained of left-sided abdominal pain, headaches, and vomiting. She was found to have hypertension, papillcedema, and a non-functioning left kidney. A diagnosis of extra-adrenal phmochromocytoma obstructing the left ureter was made. The tumour was removed successfully. Some points arising from the operation and from the establishment of the diagnosis are A
discussed. We should like to thank Prof. S. G. Graham for access to this case, Dr. J. J. Lewis of the department of experimental pharmacology, University of Glasgow, and our colleagues of the Royal Hospital for Sick Children and the Royal Infirmary, Glasgow, for advice and for carrying out the radiological, biological, and biochemical procedures. REFERENCES
Cook, J. E., Urich, R. W., Sample, H. G., Jr., Fawcett, N. W. (1960) Ann. intern. Med. 52, 126. Farley, S. E., Smith, C. L. (1959) J. Urol. 81, 130. Kennedy, J. S., Symington, T., Woodger, B. A. (1961) J. Path. Bact. (in the press). Lancet (1960), i, 969. Macgregor. A. R. (1960) Pathology of Infancy and Childhood. Edinburgh. McMillan, M. (1956) Lancet, ii, 284. Nelson, W. E. (1959) Textbook of Pediatrics. Philadelphia. Stowens, D. (1960) Pediatric Pathology. Baltimore. Symington, T., Goodall, A. L. (1953) Glasg. med. J. 34, 75. Tevetoglu, F., Lee, C. H. (1956) Amer. J. Dis. Child. 91, 365. Wall, B., Rose, D. K. (1951) J. Urol. 66, 305. Willis, R. A. (1953) Pathology of Tumours. London.
DANGER OF AIR EMBOLISM IN HIGH-PRESSURE BLOOD-TRANSFUSIONS P. C. BEWES M.B. Cantab. LATE OBSTETRIC HOUSE-SURGEON, LAMBETH
HOSPITAL, LONDON, S.E.11
VARIOUS types of pump are now widely used to restore the blood-volume rapidly in severe oligxmic shock (Melrose and Shackman 1951). Pumps have their dangers, however, and among these, the danger of air embolism can be disastrous. A number of cases of air embolism following the use of high-pressure transfusions have been described. In one, air was thought to have entered through the top of the filter candle when the level of blood in the bottle was low and the lower part of the filter was partly occluded with coagulum (Doyle and Frodsham 1949). In another, involving the use of the Martin pump, air was thought to have entered through perforations in the rubber tubing just above the pump (Langmaid and Mushin 1955). In the case described here, another source of air was
pressure of
70/0 mm. Hg, a rapid pulse (ahnost imperceptible at the wrist), and peripheral vasoconstriction. She had to be returned to the theatre for packing the uterus, and to make her fit for the operation a rapid transfusion was necessary, for which the Martin pump (Martin 1954) was used. Before and during the operation she received 5 pints of fluid (2 of 6% dextran and 3 of blood). Of this fluid 3 pints was given by means of the pump. The transfusion was given by means of a cannula tied into the long saphenous vein at the ankle. A constant watch was kept on the fluid-level in the drip-chamber and on the amount of blood in the bottle, to guard against massive air embolism. The patient returned to the ward in good condition, and her
blood-pressure was 145/80 mm. Hg, although continued bleeding had eventually necessitated a hysterectomy. A further
pint
of blood
was run-
ning in slowly when she returned
to
the ward. She died suddenly about half an hour after the operation, when this bottle was still half full. Fig. l-Experimental apA coroner’s postmortem examinaparatus for determintion showed that death was due to ing source of air bubbles during bloodair embolism. Although only a few transfusion. millilitres of air had entered the these patient’s circulation, proved fatal as they had entered the basilar artery, bypassing the pulmonary circulation through a widely patent foramen ovale. Although all the usual precautions had been taken with the transfusion (Ministry of Health 1958) the transfusion was thought the source of the air that had entered the
circulation.
Experimental Investigation A standard red-rubber-and-glass blood giving-set was assembled and the tubing and drip-chamber filled with water in the usual way. To represent the patient, a bottle was fitted with a trap for air bubbles and was completely filled with water. The needle of the giving-set was pushed into the rubber bung of the "patient" (fig. 1). At first the drip was allowed to run freely under the influence of gravity. Small bubbles at once became trapped below the fluid-level in the drip-chamber, held
responsible. Case-report A fit young woman who had had a normal pregnancy and labour was found to require evacuation of the uterus seven days after delivery. A few hours after the operation, she began to lose blood heavilv and became shocked. She bar) a hinrtd-
Fig. 2-Air bubbles trapped in drip-chamber.
Fig. 3-Drip-chamber before and after use of Fig. 4-Drip-chamber completely filled with blood.
Martin pump.
430 down by the rapid flow of the jet of water (fig. 2). Some of these bubbles would suddenly disappear from the drip-chamber, to appear a moment later in the " patient ". The Martin pump was then attached to the rubber tubing just below the drip-chamber to simulate the way in which blood is given rapidly under pressure. When the pump was operated, the fluid inside the drip-chamber became churned up with bubbles of air, and a steady stream of small
bubbles
the " patient ". After a pint given in this way, the level of the water in the drip-chamber had risen-i.e., some air had been lost from the drip chamberand this rise in level corresponded with a loss of 7 c.cm. of air from the chamber. The " patient " was found to contain 7 c.cm. of air (fig. 3). Repeatwas seen to enter
of water had been
the experiment with the Higginson syringe, instead of with the Martin pump, attached to the air-inlet of the blood bottle gave essentially similar results. The newer Capon Heaton plastic disposable giving-set (Jenkins 1959) was liable to the same trouble, in this respect being no better than the old giving-set. The use of blood in the experiments Fig. 5-Filling the filter-chamber of Capon Heaton plastic giving-set. made little difference, except that the bubbles were smaller and that it was impossible to see them below the fluid-level in the drip-chamber, thus giving a false frothing, until this is as completely full of blood as possible (fig. 5). sense of security. The result was the same-the level of 3. Bend the filter-chamber carefully (fig. 6) so that the dripfluid in the drip-chamber was seen to rise after the use of chamber, partially filled with blood, is inverted with the air the pump, and 7 c.cm. of air was found in the " patient ". bubble
ing
uppermost.
Discussion
The amounts of air are not great. Evidently with each pint of fluid given with the Martin pump about 7 c.cm. of air is given in the form of small bubbles. That this is not usually serious is shown by the large numbers of patients
who have received transfusions with this pump without apparent ill-effect. This patient, however, had an unsuspected abnormality in the heart which allowed bubbles of air to bypass the lungs and to cause paradoxical embolism. Both auscultation of the heart and X-radiography of the chest were normal. A patent foramen ovale is not uncommon, and I have been informed of a similar case of paradoxical air embolism from a similar cause. Clinically unimportant patency of the foramen ovale has, in fact, been reported in nearly a quarter of all necropsies
(White 1947). All patients requiring rapid transfusions should be regarded as having a potentially patent foramen ovale. Using standard apparatus, a safe method of transfusion which does not allow the giving of any air is possible if one simple principle is observed-namely, that if any form of pump is used to speed up the rate of transfusion, the dripchamber must be completely emptied of air when the giving-set is assembled and filled with blood (fig. 4). This is easy with the standard red-rubber-and-glass giving-sets -the drip-chamber has only to be inverted during the filling of the set with blood, and all air will be displaced from below upwards as the chamber fills. To expel air from the filter-chamber and drip-chamber of the Capon Heaton disposable plastic giving-set is technically more difficult, but is possible if the apparatus is filled thus: 1. Having connected the set with the blood bottle in the usual way (Jenkins 1959), close the regulating clamp immediately below the drip-chamber and suspend the bottle and the air-filter tube from the drip-stand. 2. Gently squeeze and release the filter-chamber, avoiding
4. Remove the sheath on the air-filter tube that acts as an air inlet to the blood bottle, and gently release the regulating clamp. The drip-chamber will now fill with blood, expelling all air. The tubing of the set will fill with blood, and the dripchamber may now be allowed to hang normally. If at this stage more air has appeared in the filter-chamber, this may be
expelled by gentle squeezing. When all air has been expelled from the tubing, the drip-set is ready for use with the pump.
By the use of this technique, both the Martin pump and the Higginson syringe can safely be used without any danger. Using the same apparatus (fig. 1), no bubbles of air appeared in the " patient " even when blood was transfused at very high speeds. (The drip-chamber is not rendered functionless by filling it with fluid completely. It now works very well as an air-bubble trap should any air be delivered from the blood bottle.) The technique is easily mastered and is not time-consuming. Summary A maternal death took place from air embolism associated with the use of the Martin pump for blood-transfusion. The patient had a patent foramen ovale, and in this condition even small amounts of air may prove fatal. Experiments show that, when the Martin pump or the Higginson syringe are used, air from the drip-chamber inevitably finds its way into the patient. A simple technique for obviating this is described which should be employed whenever the Martin pump or the Higginson syringe is used for rapid transfusion. I thank Mr.
Philip Rhodes for his help and for permission to of the case, and Dr. Donald Teare who performed the postmortem examination. publish details
REFERENCES
Doyle, G. B., Frodsham, P. (1949) Lancet, i, 735. Jenkins, W. J., Knowles, G. S. A., Stone, B., Tovey, G. H., Sharpe, R.A. (1959) ibid. 1, 139. Langmaid, C., Mushin, W. W. (1955) Brit. med. J. ii, 1142. Martin, P. (1954) Lancet, ii, 1002. Melrose, D. G., Shackman, R. (1951) ibid. i, 1144. Ministry of Health (1958) Notes on Transfusion; p. 19. White, P. D. (1947) Heart Disease ; p. 293. New York.
catecholamines
are
produced selectively by malignant
tumours, but evidence against this has recently been shown (Kennedy et al. 1961). The site of origin of this tumour remains in doubt; it probably was the organ of Zuckerkandl, butthe tumour could have originated from any of the paraganglia related to the autonomic nerves in that region. In contrast to the case described by Farley and Smith (1959), which is the only other one known to us that presented with a nonfunctioning kidney, the tumour did not arise from the bladder. Cook et al. (1960) describe 3 cases of phaeochromocytomata of the organ of Zuckerkandl and review 3 others. They noted abdominal symptoms as being the rule in such cases, ascribing them to compression of
surrounding structures. Summary
12-year-old girl complained of left-sided abdominal pain, headaches, and vomiting. She was found to have hypertension, papillcedema, and a non-functioning left kidney. A diagnosis of extra-adrenal phmochromocytoma obstructing the left ureter was made. The tumour was removed successfully. Some points arising from the operation and from the establishment of the diagnosis are A
discussed. We should like to thank Prof. S. G. Graham for access to this case, Dr. J. J. Lewis of the department of experimental pharmacology, University of Glasgow, and our colleagues of the Royal Hospital for Sick Children and the Royal Infirmary, Glasgow, for advice and for carrying out the radiological, biological, and biochemical procedures. REFERENCES
Cook, J. E., Urich, R. W., Sample, H. G., Jr., Fawcett, N. W. (1960) Ann. intern. Med. 52, 126. Farley, S. E., Smith, C. L. (1959) J. Urol. 81, 130. Kennedy, J. S., Symington, T., Woodger, B. A. (1961) J. Path. Bact. (in the press). Lancet (1960), i, 969. Macgregor. A. R. (1960) Pathology of Infancy and Childhood. Edinburgh. McMillan, M. (1956) Lancet, ii, 284. Nelson, W. E. (1959) Textbook of Pediatrics. Philadelphia. Stowens, D. (1960) Pediatric Pathology. Baltimore. Symington, T., Goodall, A. L. (1953) Glasg. med. J. 34, 75. Tevetoglu, F., Lee, C. H. (1956) Amer. J. Dis. Child. 91, 365. Wall, B., Rose, D. K. (1951) J. Urol. 66, 305. Willis, R. A. (1953) Pathology of Tumours. London.
DANGER OF AIR EMBOLISM IN HIGH-PRESSURE BLOOD-TRANSFUSIONS P. C. BEWES M.B. Cantab. LATE OBSTETRIC HOUSE-SURGEON, LAMBETH
HOSPITAL, LONDON, S.E.11
VARIOUS types of pump are now widely used to restore the blood-volume rapidly in severe oligxmic shock (Melrose and Shackman 1951). Pumps have their dangers, however, and among these, the danger of air embolism can be disastrous. A number of cases of air embolism following the use of high-pressure transfusions have been described. In one, air was thought to have entered through the top of the filter candle when the level of blood in the bottle was low and the lower part of the filter was partly occluded with coagulum (Doyle and Frodsham 1949). In another, involving the use of the Martin pump, air was thought to have entered through perforations in the rubber tubing just above the pump (Langmaid and Mushin 1955). In the case described here, another source of air was
pressure of
70/0 mm. Hg, a rapid pulse (ahnost imperceptible at the wrist), and peripheral vasoconstriction. She had to be returned to the theatre for packing the uterus, and to make her fit for the operation a rapid transfusion was necessary, for which the Martin pump (Martin 1954) was used. Before and during the operation she received 5 pints of fluid (2 of 6% dextran and 3 of blood). Of this fluid 3 pints was given by means of the pump. The transfusion was given by means of a cannula tied into the long saphenous vein at the ankle. A constant watch was kept on the fluid-level in the drip-chamber and on the amount of blood in the bottle, to guard against massive air embolism. The patient returned to the ward in good condition, and her
blood-pressure was 145/80 mm. Hg, although continued bleeding had eventually necessitated a hysterectomy. A further
pint
of blood
was run-
ning in slowly when she returned
to
the ward. She died suddenly about half an hour after the operation, when this bottle was still half full. Fig. l-Experimental apA coroner’s postmortem examinaparatus for determintion showed that death was due to ing source of air bubbles during bloodair embolism. Although only a few transfusion. millilitres of air had entered the these patient’s circulation, proved fatal as they had entered the basilar artery, bypassing the pulmonary circulation through a widely patent foramen ovale. Although all the usual precautions had been taken with the transfusion (Ministry of Health 1958) the transfusion was thought the source of the air that had entered the
circulation.
Experimental Investigation A standard red-rubber-and-glass blood giving-set was assembled and the tubing and drip-chamber filled with water in the usual way. To represent the patient, a bottle was fitted with a trap for air bubbles and was completely filled with water. The needle of the giving-set was pushed into the rubber bung of the "patient" (fig. 1). At first the drip was allowed to run freely under the influence of gravity. Small bubbles at once became trapped below the fluid-level in the drip-chamber, held
responsible. Case-report A fit young woman who had had a normal pregnancy and labour was found to require evacuation of the uterus seven days after delivery. A few hours after the operation, she began to lose blood heavilv and became shocked. She bar) a hinrtd-
Fig. 2-Air bubbles trapped in drip-chamber.
Fig. 3-Drip-chamber before and after use of Fig. 4-Drip-chamber completely filled with blood.
Martin pump.
430 down by the rapid flow of the jet of water (fig. 2). Some of these bubbles would suddenly disappear from the drip-chamber, to appear a moment later in the " patient ". The Martin pump was then attached to the rubber tubing just below the drip-chamber to simulate the way in which blood is given rapidly under pressure. When the pump was operated, the fluid inside the drip-chamber became churned up with bubbles of air, and a steady stream of small
bubbles
the " patient ". After a pint given in this way, the level of the water in the drip-chamber had risen-i.e., some air had been lost from the drip chamberand this rise in level corresponded with a loss of 7 c.cm. of air from the chamber. The " patient " was found to contain 7 c.cm. of air (fig. 3). Repeatwas seen to enter
of water had been
the experiment with the Higginson syringe, instead of with the Martin pump, attached to the air-inlet of the blood bottle gave essentially similar results. The newer Capon Heaton plastic disposable giving-set (Jenkins 1959) was liable to the same trouble, in this respect being no better than the old giving-set. The use of blood in the experiments Fig. 5-Filling the filter-chamber of Capon Heaton plastic giving-set. made little difference, except that the bubbles were smaller and that it was impossible to see them below the fluid-level in the drip-chamber, thus giving a false frothing, until this is as completely full of blood as possible (fig. 5). sense of security. The result was the same-the level of 3. Bend the filter-chamber carefully (fig. 6) so that the dripfluid in the drip-chamber was seen to rise after the use of chamber, partially filled with blood, is inverted with the air the pump, and 7 c.cm. of air was found in the " patient ". bubble
ing
uppermost.
Discussion
The amounts of air are not great. Evidently with each pint of fluid given with the Martin pump about 7 c.cm. of air is given in the form of small bubbles. That this is not usually serious is shown by the large numbers of patients
who have received transfusions with this pump without apparent ill-effect. This patient, however, had an unsuspected abnormality in the heart which allowed bubbles of air to bypass the lungs and to cause paradoxical embolism. Both auscultation of the heart and X-radiography of the chest were normal. A patent foramen ovale is not uncommon, and I have been informed of a similar case of paradoxical air embolism from a similar cause. Clinically unimportant patency of the foramen ovale has, in fact, been reported in nearly a quarter of all necropsies
(White 1947). All patients requiring rapid transfusions should be regarded as having a potentially patent foramen ovale. Using standard apparatus, a safe method of transfusion which does not allow the giving of any air is possible if one simple principle is observed-namely, that if any form of pump is used to speed up the rate of transfusion, the dripchamber must be completely emptied of air when the giving-set is assembled and filled with blood (fig. 4). This is easy with the standard red-rubber-and-glass giving-sets -the drip-chamber has only to be inverted during the filling of the set with blood, and all air will be displaced from below upwards as the chamber fills. To expel air from the filter-chamber and drip-chamber of the Capon Heaton disposable plastic giving-set is technically more difficult, but is possible if the apparatus is filled thus: 1. Having connected the set with the blood bottle in the usual way (Jenkins 1959), close the regulating clamp immediately below the drip-chamber and suspend the bottle and the air-filter tube from the drip-stand. 2. Gently squeeze and release the filter-chamber, avoiding
4. Remove the sheath on the air-filter tube that acts as an air inlet to the blood bottle, and gently release the regulating clamp. The drip-chamber will now fill with blood, expelling all air. The tubing of the set will fill with blood, and the dripchamber may now be allowed to hang normally. If at this stage more air has appeared in the filter-chamber, this may be
expelled by gentle squeezing. When all air has been expelled from the tubing, the drip-set is ready for use with the pump.
By the use of this technique, both the Martin pump and the Higginson syringe can safely be used without any danger. Using the same apparatus (fig. 1), no bubbles of air appeared in the " patient " even when blood was transfused at very high speeds. (The drip-chamber is not rendered functionless by filling it with fluid completely. It now works very well as an air-bubble trap should any air be delivered from the blood bottle.) The technique is easily mastered and is not time-consuming. Summary A maternal death took place from air embolism associated with the use of the Martin pump for blood-transfusion. The patient had a patent foramen ovale, and in this condition even small amounts of air may prove fatal. Experiments show that, when the Martin pump or the Higginson syringe are used, air from the drip-chamber inevitably finds its way into the patient. A simple technique for obviating this is described which should be employed whenever the Martin pump or the Higginson syringe is used for rapid transfusion. I thank Mr.
Philip Rhodes for his help and for permission to of the case, and Dr. Donald Teare who performed the postmortem examination. publish details
REFERENCES
Doyle, G. B., Frodsham, P. (1949) Lancet, i, 735. Jenkins, W. J., Knowles, G. S. A., Stone, B., Tovey, G. H., Sharpe, R.A. (1959) ibid. 1, 139. Langmaid, C., Mushin, W. W. (1955) Brit. med. J. ii, 1142. Martin, P. (1954) Lancet, ii, 1002. Melrose, D. G., Shackman, R. (1951) ibid. i, 1144. Ministry of Health (1958) Notes on Transfusion; p. 19. White, P. D. (1947) Heart Disease ; p. 293. New York.