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CARBONIC ANHYDRASE INHIBITION
920 This method has the advantages of the good support and quick healing associated with non-absorbable sutures, combined with freedom from the spectre of chronic sinus formation. The method has been in use for 18 months, in parallel with a series in which 40-day catgut was used, and it works well. It has the advantages over throughand-through or figure-of-eight sutures involving the skin of being much less painful and leaving less ugly scars. I should like to add one comment on the technique, described by Mr. Oldham (April 16), of using a doubled suture, cutting the terminal loop, and tying the ends together. In this method the terminal loop is of singlestrand thickness, and a suture, like a chain, has the strength only of its weakest part. I agree with him that it is easy, and desirable, when burying suture material to tie the initial and final knots on the peritoneal aspect of the aponeurosis. HERBERT HAXTON. Manchester. CARBONIC ANHYDRASE INHIBITION
SIR,-As acetazoleamide (’Diamox’) can lower the arterial-blood CO2 level it would seem to be the ideal diuretic to use in the treatment of emphysema heartfailure because respiratory acidosis is common in this condition. In your leading article of April 2 you mention the favourable results that have been reported 12in the treatment of emphysema heart-failure and respiratory acidosis respectively. My experience, though limited, differs from that of the workers you mention. There is no doubt that diamox can cause a diuresis in heart-failure of varying cause, but in assessing its value in emphysema heart-failure one must remember that an acute respiratory infection may precipitate cardiac failure in an emphysematous patient and that the oedema clears as the infection subsides. Diamox should therefore stable " be tested in those with chronic failure and a chest. Such cases are uncommon. I have treated 2 such patients with diamox and compared the diuresis with that resulting from mercurials. Diamox can lower the arterial CO2 level, and the importance of this in the treatment of acute or chronic respiratory acidosis is at once obvious. I have treated 5 emphysematous patients suffering from an acute respiratory infection and complicated by heart-failure and drowsiness ; another 2 patients also had CO2 narcosis and 2 had chronic as a result of oxygen therapy ; "
respiratory acidosis, of the acidosis in administration.
During diamox therapy the diet was either salt-free or contained 1 g. of sodium a day. Initially the dosage of diamox was 8 to 12 mg. per kg. body-weight daily but it was found that 250 mg. twice daily was as effective and free from toxic effects. A single daily dose of 500 mg. often caused headache and drowsiness. Brachial-artery puncture was done on the day before diamox was given, and on the second or third day of therapy two to three hours after the morning dose of the drug. The results are shown in the accompanying table. It will be seen that there was a diuresis in those with failure due to an acute respiratory infection, but not in those with chronic failure. The 2 patients with chronic failure did however respond to mercurials and ammonium chloride. The mental state improved in only 1 patient-a man admitted because of a respiratory infection complicated by drowsiness and heart. failure. Oxygen therapy produced mental confusion and sweating. He was given 625 mg. of diamox in a single dose in the morning and the oxygen was continued intermittently. After three days he was fully orientated. At this point the arterialblood pH was 7-33, the pC02 79 mm., the C02 content 78 vols. %, and the O2 saturation 87-5%. Diamox was then stopped and the arterial blood twenty-four hours later showed a pH of 7-42, a pC02 of 57 mm., a CO2 content of 69 vols. %, and an O2 saturation of 78%. Two days later, still without diamox, mental clarity was retained and the blood findings were : pH 7-35, pC02 65 mm., CO2 content 68 vols. %, and O2 saturation 90%. All the samples were taken with the patient breathing oxygen. In view of these findings I do not think that the improvement in the mental state can be attributed to diamox.
patients were adversely affected by the drug. This surprising, for, although the arterial CO2 was usually reduced, the pCO2 was not significantly lowered and indeed was often raised. Nadell2 reported well of the use of diamox in 3 cases of respiratory acidosis. In one, case she states that the drowsiness, cured by diamox, returned seven days after the drug had been discontinued. From the data it is seen that this change was associated with a fall in pH and a rise in CO2 and that on resumption of the drug the pH rose and the CO2 and pCO2 fell. Observations that I have made of similar events occurring under similar circumstances in patients not receiving 5
is not
diamox lead me to believe that the fluctuations in the mental state are related to abrupt changes in the arterial saturation rather than to the effects of diamox. Messrs. Lederle
1.
Schwartz, W. B., Relman, A. S., Leaf, 1955, 42, 79. 2. Nadell, J. J. clin. Invest. 1952, 52, 622.
A.
Ann. intern. Med.
EFFECT OF DIAMOX IN CARDIAC
neither with oedema. The cause of them was continuous oxygen
one
kindly supplied
the diamox used in this
investigation. Chase Farm Hospital, Enfield.
FAILURE, C02 NARCOSIS,
THOMAS SIMPSON.
AND RESPIRATORY ACIDOSIS
SIR,-As acetazoleamide (’Diamox’) can lower the arterial-blood CO2 level it would seem to be the ideal diuretic to use in the treatment of emphysema heartfailure because respiratory acidosis is common in this condition. In your leading article of April 2 you mention the favourable results that have been reported 12in the treatment of emphysema heart-failure and respiratory acidosis respectively. My experience, though limited, differs from that of the workers you mention. There is no doubt that diamox can cause a diuresis in heart-failure of varying cause, but in assessing its value in emphysema heart-failure one must remember that an acute respiratory infection may precipitate cardiac failure in an emphysematous patient and that the oedema clears as the infection subsides. Diamox should therefore stable " be tested in those with chronic failure and a chest. Such cases are uncommon. I have treated 2 such patients with diamox and compared the diuresis with that resulting from mercurials. Diamox can lower the arterial CO2 level, and the importance of this in the treatment of acute or chronic respiratory acidosis is at once obvious. I have treated 5 emphysematous patients suffering from an acute respiratory infection and complicated by heart-failure and drowsiness ; another 2 patients also had CO2 narcosis and 2 had chronic as a result of oxygen therapy ; "
respiratory acidosis, of the acidosis in administration.
During diamox therapy the diet was either salt-free or contained 1 g. of sodium a day. Initially the dosage of diamox was 8 to 12 mg. per kg. body-weight daily but it was found that 250 mg. twice daily was as effective and free from toxic effects. A single daily dose of 500 mg. often caused headache and drowsiness. Brachial-artery puncture was done on the day before diamox was given, and on the second or third day of therapy two to three hours after the morning dose of the drug. The results are shown in the accompanying table. It will be seen that there was a diuresis in those with failure due to an acute respiratory infection, but not in those with chronic failure. The 2 patients with chronic failure did however respond to mercurials and ammonium chloride. The mental state improved in only 1 patient-a man admitted because of a respiratory infection complicated by drowsiness and heart. failure. Oxygen therapy produced mental confusion and sweating. He was given 625 mg. of diamox in a single dose in the morning and the oxygen was continued intermittently. After three days he was fully orientated. At this point the arterialblood pH was 7-33, the pC02 79 mm., the C02 content 78 vols. %, and the O2 saturation 87-5%. Diamox was then stopped and the arterial blood twenty-four hours later showed a pH of 7-42, a pC02 of 57 mm., a CO2 content of 69 vols. %, and an O2 saturation of 78%. Two days later, still without diamox, mental clarity was retained and the blood findings were : pH 7-35, pC02 65 mm., CO2 content 68 vols. %, and O2 saturation 90%. All the samples were taken with the patient breathing oxygen. In view of these findings I do not think that the improvement in the mental state can be attributed to diamox.
patients were adversely affected by the drug. This surprising, for, although the arterial CO2 was usually reduced, the pCO2 was not significantly lowered and indeed was often raised. Nadell2 reported well of the use of diamox in 3 cases of respiratory acidosis. In one, case she states that the drowsiness, cured by diamox, returned seven days after the drug had been discontinued. From the data it is seen that this change was associated with a fall in pH and a rise in CO2 and that on resumption of the drug the pH rose and the CO2 and pCO2 fell. Observations that I have made of similar events occurring under similar circumstances in patients not receiving 5
is not
diamox lead me to believe that the fluctuations in the mental state are related to abrupt changes in the arterial saturation rather than to the effects of diamox. Messrs. Lederle
1.
Schwartz, W. B., Relman, A. S., Leaf, 1955, 42, 79. 2. Nadell, J. J. clin. Invest. 1952, 52, 622.
A.
Ann. intern. Med.
EFFECT OF DIAMOX IN CARDIAC
neither with oedema. The cause of them was continuous oxygen
one
kindly supplied
the diamox used in this
investigation. Chase Farm Hospital, Enfield.
FAILURE, C02 NARCOSIS,
THOMAS SIMPSON.
AND RESPIRATORY ACIDOSIS