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PREMEDICATION WITH ATROPINE BY MOUTH
491 cell double trait in the last three months of
two
successive
pregnancies. Our findings suggest that folic-acid deficiency is an important and common complicating factor in the acute and chronic anaemia of many patients with thalasssemia major. Reduced gastrointestinal absorption of folic acid is probably one of the causative factors. The folic-acid deficiency was most clearly revealed by increased formiminoglutamicaciduria after histidine metabolic loading. It is of diagnostic and theoretical interest that moderate to severe folic-acid deficiency existed in the absence of megaloblastic characteristics in the erythroid or myeloid series of the blood and marrow. Folic-acid deficiency would not have been suspected on morphological grounds in most of our patients. The haemoglobin level was increased or maintained, and the biochemical and, when present, the morphological manifestations of folic-acid deficiency disappeared after giving folic acid. These observations raise
peutic approach to the
acute
chronic disease and of
expectations of and
a new theraanxmia in this reduce the need for
recurrent
a means to
transfusions. These studies were supported in part by a grant-in-aid from the Cooley’s Anaemia Blood and Research Foundation for Children (New York) and the U.S. Public Health Service.
the filter
screen.
Experimental then carin the laboratory with dextran-a fluid similar to blood, but clear so that any air bubbles could be runs were
ried
out
photographed. Photographs
were
taken with a highspeed electronic flash of 1/1000th sec. duration to Fig. 1. freeze movement. While the machine was running, small and minute bubbles could be demonstrated with pump and oxygenator turning at 36 r.p.m. (2 litres per min.). Bubble formation was much increased by increasing the flow-rate, or by allowing the level in the oxygenator reservoir housing to fall below the central fulcrum pin. Fig. 1 shows this very clearly; the pump and oxygenator were running at 67 r.p.m. (3-7 litres per min.).
Hematology and Nutrition Laboratory, A. LEONARD LUHBY Department of Pediatrics, New York Medical College, JACK New York, N.Y., U.S.A. JACK M. M. COOPERMAN.
PREMEDICATION WITH ATROPINE BY MOUTH
SIR,—Iread with interest Dr. Dimsdale’s comments (May 20) on the excellent article by Dr. Joseph and Dr. Vale on oral atropine.’- I would like to endorse most heartily the more widespread giving of drugs orally and the attempt to limit the innumerable and quite often needless injections carried on in hospitals. On the other hand, I am a firm believer in intravenous induction in the anaathetic room or dental surgery performed by a competent anxsthetist using new small needles. This procedure can be nearly painless. As far as oral atropine is concerned, I have now changed from 0-8 mg. (gr. 1/75) to 1-2 mg. (gr. 1/so) and find a big improvement. Nevertheless there are conditions in which atropine should be injected. If an irritant anæsthetic—e.g., ether-is given, then in my experience gr. 1/50 atropine by mouth is not as effective as gr. by injection. Asquith and I2 when investigating the longer-acting ’Hyperduric Atropine’, similarly found it quite satisfactory provided ether was not administered. Ether will probably be given more rarely now that halothane has been introduced and with the advances in pædiatric anxsthesia with nitrous oxide and oxygen and controlled respiration with muscle
Fig. 2. Further photographs proved that, unless the stainless steel wire mesh inside the filter was precisely assembled as detailed below, small air bubbles, though invisible to the naked eye, could pass into the arterial line. The greater the rate of perfusion, the more air-bubbles could be photographed which had escaped filtering. A similar picture resulted if the reservoir level in the oxygenator was allowed to fall well below the central fulcrum pin (seen in fig. 1), even at low perfusionrates.
Being potentially lethal, this intermittent filter failure was remedied, before any patients were perfused, by the following modifications :
(1) Special soft silirubber seals in which the stainless steel wire mesh ends would embed under cone
relaxants.
Finally, why not give sedatives postoperatively by mouth instead of by injection. Most patients, excluding those who have had abdominal operations, can take this sedation by mouth; and provided it is given in larger doses than by injection it is highly effective. How ridiculous it -is to see a fit young man having a cup of tea and a slice of toast postoperatively after, say, a meniscectomy, and a nurse injecting 100 mg. pethidine or gr. 1/4 morphine subcutaneously. Little Bromwich General Birmingham, 9.
Hospital,
Hospital, EUGENE EUGENE
SIR,—When perfusing dogs with this machine, one apparently inexplicable death drew attention to the possibility of small air-bubbles passing through or round Joseph, M. C., Vale, R. J. Lancet, 1960, ii, Asquith, E., Thomas, E. ibid. 1948, ii, 930.
1060.
were mm.
internal diameter x 51 mm. external diameter x 2 mm. thick, silicone rubber E.360.) (2) The wire mesh,
cleaned in ether to grease and metal dust, is examined for weaving flaws, and then fitted inside The inside overlap is remove
THOMAS.
A MODIFIED ARTERIAL FILTER ASSEMBLY FOR THE MELROSE HEART-LUNG MACHINE
1. 2.
compression made. (44-5
Fig. 3.
supporting cylinder exactly endwise. 3/4 in. (fig. 2). (3) Close overlap and constant positioning during assembly of the complete filter is guaranteed by three expanding stainless steel circlips fitted in the middle and near each end (fig. 3). the
After these modifications, repeat tests and photographs showed that no air-bubbles passed the filter whatever the rate of perfusion. Obviously air can pass the filter if its air-trapping
two
successive
pregnancies. Our findings suggest that folic-acid deficiency is an important and common complicating factor in the acute and chronic anaemia of many patients with thalasssemia major. Reduced gastrointestinal absorption of folic acid is probably one of the causative factors. The folic-acid deficiency was most clearly revealed by increased formiminoglutamicaciduria after histidine metabolic loading. It is of diagnostic and theoretical interest that moderate to severe folic-acid deficiency existed in the absence of megaloblastic characteristics in the erythroid or myeloid series of the blood and marrow. Folic-acid deficiency would not have been suspected on morphological grounds in most of our patients. The haemoglobin level was increased or maintained, and the biochemical and, when present, the morphological manifestations of folic-acid deficiency disappeared after giving folic acid. These observations raise
peutic approach to the
acute
chronic disease and of
expectations of and
a new theraanxmia in this reduce the need for
recurrent
a means to
transfusions. These studies were supported in part by a grant-in-aid from the Cooley’s Anaemia Blood and Research Foundation for Children (New York) and the U.S. Public Health Service.
the filter
screen.
Experimental then carin the laboratory with dextran-a fluid similar to blood, but clear so that any air bubbles could be runs were
ried
out
photographed. Photographs
were
taken with a highspeed electronic flash of 1/1000th sec. duration to Fig. 1. freeze movement. While the machine was running, small and minute bubbles could be demonstrated with pump and oxygenator turning at 36 r.p.m. (2 litres per min.). Bubble formation was much increased by increasing the flow-rate, or by allowing the level in the oxygenator reservoir housing to fall below the central fulcrum pin. Fig. 1 shows this very clearly; the pump and oxygenator were running at 67 r.p.m. (3-7 litres per min.).
Hematology and Nutrition Laboratory, A. LEONARD LUHBY Department of Pediatrics, New York Medical College, JACK New York, N.Y., U.S.A. JACK M. M. COOPERMAN.
PREMEDICATION WITH ATROPINE BY MOUTH
SIR,—Iread with interest Dr. Dimsdale’s comments (May 20) on the excellent article by Dr. Joseph and Dr. Vale on oral atropine.’- I would like to endorse most heartily the more widespread giving of drugs orally and the attempt to limit the innumerable and quite often needless injections carried on in hospitals. On the other hand, I am a firm believer in intravenous induction in the anaathetic room or dental surgery performed by a competent anxsthetist using new small needles. This procedure can be nearly painless. As far as oral atropine is concerned, I have now changed from 0-8 mg. (gr. 1/75) to 1-2 mg. (gr. 1/so) and find a big improvement. Nevertheless there are conditions in which atropine should be injected. If an irritant anæsthetic—e.g., ether-is given, then in my experience gr. 1/50 atropine by mouth is not as effective as gr. by injection. Asquith and I2 when investigating the longer-acting ’Hyperduric Atropine’, similarly found it quite satisfactory provided ether was not administered. Ether will probably be given more rarely now that halothane has been introduced and with the advances in pædiatric anxsthesia with nitrous oxide and oxygen and controlled respiration with muscle
Fig. 2. Further photographs proved that, unless the stainless steel wire mesh inside the filter was precisely assembled as detailed below, small air bubbles, though invisible to the naked eye, could pass into the arterial line. The greater the rate of perfusion, the more air-bubbles could be photographed which had escaped filtering. A similar picture resulted if the reservoir level in the oxygenator was allowed to fall well below the central fulcrum pin (seen in fig. 1), even at low perfusionrates.
Being potentially lethal, this intermittent filter failure was remedied, before any patients were perfused, by the following modifications :
(1) Special soft silirubber seals in which the stainless steel wire mesh ends would embed under cone
relaxants.
Finally, why not give sedatives postoperatively by mouth instead of by injection. Most patients, excluding those who have had abdominal operations, can take this sedation by mouth; and provided it is given in larger doses than by injection it is highly effective. How ridiculous it -is to see a fit young man having a cup of tea and a slice of toast postoperatively after, say, a meniscectomy, and a nurse injecting 100 mg. pethidine or gr. 1/4 morphine subcutaneously. Little Bromwich General Birmingham, 9.
Hospital,
Hospital, EUGENE EUGENE
SIR,—When perfusing dogs with this machine, one apparently inexplicable death drew attention to the possibility of small air-bubbles passing through or round Joseph, M. C., Vale, R. J. Lancet, 1960, ii, Asquith, E., Thomas, E. ibid. 1948, ii, 930.
1060.
were mm.
internal diameter x 51 mm. external diameter x 2 mm. thick, silicone rubber E.360.) (2) The wire mesh,
cleaned in ether to grease and metal dust, is examined for weaving flaws, and then fitted inside The inside overlap is remove
THOMAS.
A MODIFIED ARTERIAL FILTER ASSEMBLY FOR THE MELROSE HEART-LUNG MACHINE
1. 2.
compression made. (44-5
Fig. 3.
supporting cylinder exactly endwise. 3/4 in. (fig. 2). (3) Close overlap and constant positioning during assembly of the complete filter is guaranteed by three expanding stainless steel circlips fitted in the middle and near each end (fig. 3). the
After these modifications, repeat tests and photographs showed that no air-bubbles passed the filter whatever the rate of perfusion. Obviously air can pass the filter if its air-trapping