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ADRENALECTOMY AND HYPOPHYSECTOMY
156
(the 5th had fever, dizziness, general malaise, and vomiting). Dr. Russell and his colleagues reported headache during treatment and other minor symptoms attributable to the drug, but they state that these side-effects were as controls as among those receiving common among griseofulvin. Although the drug could not be given to our patient for the long period normally accepted as necessary, it is nevertheless considered probable by some workersthat the laying down of a bed of healthy nail during the three weeks she had treatment may presage cure. The sensitivity tests to griseofulvin were kindly carried
out
by
seal the hole in the anterior wall of the sella. We abandoned the method and would advise otolaryngologists, who might be influenced by Mr. Macbeth’s letter to explore the method, that unless they can suture the dural defect in the floor of the pituitary fossa necessarily created, their operation will be followed by cerebrospinal-fluid rhinorrhoea in a large number of cases unless it is incomplete and does not reach the pituitary stalk. It is tempting to think that such a dural defect can be made good by packing it with muscle, fibrin, or some form of plastic material, but they and their patients will find to their sorrow, as we did, that this is not so. Department of Neurological Surgery, Royal Victoria Hospital, ALEX R. TAYLOR.
screws to
Belfast.
Dr. A. Scott.
Dorking, Surrey.
PATRICIA GOODE.
PAY INCREASE TO MEDICAL
SUPERINTENDENTS SIR,-In his letter of July 9, Dr. Gore states that the revocation of Statutory Instrument 1948, no. 419, will mean that the responsibility of a medical superintendent of a mental hospital will be neither greater nor less than that of his fellow consultants. We know that the Minister has decided that the appointment of a superintendent shall no longer be compulsory, but it would be strange if he decided that when one is appointed he should not be permitted to superintend. Many consultants still think that a special-purpose hospital needs a doctor in day-to-day control, and would welcome the appointment of one of their colleagues to take this responsibility as an alternative to their being under the tutelage of a lay administrator. Whether the appointment should be on a temporary or permanent basis is a matter of opinion and does not affect the main i""l1f’-nnr does the nrnnosed
Northgate and District Hospital, Morpeth, Northumberland.
extra
f,25f).
C. GUY MILLMAN.
ADRENALECTOMY AND HYPOPHYSECTOMY SIR,-Ishould like to comment on Mr. Macbeth’s letter of June 25 advocating the transnasal approach to the pituitary fossa for the ablation of the normal pituitary gland. Neurological surgeons have, of course, been aware of this possibility since the first decade of the century and 167 of Cushing’s 260 operations for decompression of pituitary tumours were done by the transseptal trans-
sphenoidal route.4 The method was largely superseded by the transfrontal approach about 1928 but was revived by otolaryngologists, notably Hirsch, in the 1930s. Actuated by the same sentiments as those expressed by Mr. Macbeth-that the operation would be less disturbing, the convalescence smoother, and the hospital stay shorter-we operated on a group of patients in 1957 by the transsphenoidal route. We quickly became aware of the difference between the safe operation for the removal of a pituitary tumour in which the subarachnoid spaces in the area have been previously obliterated by tumour growth and the operation for complete removal of a normal pituitary gland which results in a free communication being established between the cerebrospinalfluid pathways round the pituitary stalk and the nasal sinuses. All
our
patients developed cerebrospinal-fluid rhinorrhoea,
of them a very troublesome recurring meningitis, and all of them were dead within five months of the operation. This might have been predicted from the high complication-rate following mechanical insertion of yttrium rods through the sinuses reported by Forrest,5 somewhat reduced by using two
3. 4. 5.
Scott, A. Personal communication, 1960. Cushing, H. J. Amer. med. Ass. 1914, 63, 1515. Forrest, A. P. M., et al. Brit. J. Surg. 1959, 47, 61.
GUIDE FOR PUDENDAL NERVE BLOCK
SIR,-Ishould like to confirm the merits of the guide for pudendal nerve block described by Dr. Eaton and Dr. Flanagan (June 25). It has been found most useful at Perivale Maternity Hospital and elsewhere during the past eighteen months. A transvaginal pudendal block is more quickly and accurately performed using this device and new house-surgeons learn the technique easily. The guide is now being made in this country by Messrs. Down Bros. and Mayer & Phelps, Mitcham, Surrey. The gauges described are American gauges, and the equivalent English ones are no. 17 and no.
20 respectively.
Perivale
Maternity Hospital, Greenford, Middlesex.
A. M. DICKINS.
THE CAUSE OF ŒDEMA IN " COR PULMONALE"
SIR,-May we comment on the suggestion of Dr. Campbell and Dr. Short (May 28) that oedema in cor pulmonale may be due to the increased bicarbonate reabsorption which is known to occur in the presence of a raised arterial carbon-dioxide tension ?
They have perhaps not considered that increased bicarbonate reabsorption need not be accompanied by increased sodium reabsorption, since bicarbonate ions may instead be substituted for chloride ions in the reabsorbate. That such sub,stitution does occur during the compensation of respiratory acidosis is clear from the plasma-electrolyte pattern in which, characteristically, the bicarbonate concentration is high, chloride low, and sodium normal. This elevation of plasmabicarbonate at the expense of chloride will not cause expansion of the extracellular fluid with oedema formation; for this to occur, not only bicarbonate reabsorption, but also sodium
reabsorption, must increase. Evidence concerning the effect of a high pCO2 on sodium reabsorption in otherwise normal humans is very difficult to obtain, because experimental subjects cannot tolerate severe or prolonged hypercapnoea. Such human experiments as have been performed have shown neither a significant rise in sodium reabsorption nor expansion of the extracellular fluid, but they involved relatively brief and modest elevations of carbon-dioxide tension.1-a Recent studies 45 in rats exposed to carbon-dioxide concentrations between 8 and 15 % for periods of up to eleven days have also shown no significant changes in urinary sodium or in sodium balance. It may be argued, however, that the rat is not a suitable experimental model. Information concerning the response in the dog is perhaps more pertinent, since in many respects the renal function of this animal more closely resembles that of man. In the paper on chronic respiratory acidosis in dogs by Sullivan and Dormant no data on sodium balance or sodium excretion during chronic hypercapncea were reported. However, we have recently completed balance studies in five dogs exposed to carbon-dioxide concentrations of 9 to 13% for periods of up to eight days. The sodium excretion was some1. Longson, D., Mills, J. N. J. Physiol. 1953, 122, 81. 2. Barbour, A., Bull, G. M., Evans, B. M., Hugh Jones, N. C., Logotheto3. 4. 5. 6.
poulos, J. Clin. Sci. 1953, 12, 1. Barker, E. S., Singer, R. B., Elkinton, J. R., Clark, J. K. J. clin. Invest. 1957, 36, 515. Levitin, H., Branscome, W., Epstein, F. H. ibid. 1958, 37, 1667. Carter, N. W., Seldin, D. W., Teng, H. C. ibid. 1959, 38, 949. Sullivan, W. J., Dorman, P. J. ibid. 1955, 34, 268.
(the 5th had fever, dizziness, general malaise, and vomiting). Dr. Russell and his colleagues reported headache during treatment and other minor symptoms attributable to the drug, but they state that these side-effects were as controls as among those receiving common among griseofulvin. Although the drug could not be given to our patient for the long period normally accepted as necessary, it is nevertheless considered probable by some workersthat the laying down of a bed of healthy nail during the three weeks she had treatment may presage cure. The sensitivity tests to griseofulvin were kindly carried
out
by
seal the hole in the anterior wall of the sella. We abandoned the method and would advise otolaryngologists, who might be influenced by Mr. Macbeth’s letter to explore the method, that unless they can suture the dural defect in the floor of the pituitary fossa necessarily created, their operation will be followed by cerebrospinal-fluid rhinorrhoea in a large number of cases unless it is incomplete and does not reach the pituitary stalk. It is tempting to think that such a dural defect can be made good by packing it with muscle, fibrin, or some form of plastic material, but they and their patients will find to their sorrow, as we did, that this is not so. Department of Neurological Surgery, Royal Victoria Hospital, ALEX R. TAYLOR.
screws to
Belfast.
Dr. A. Scott.
Dorking, Surrey.
PATRICIA GOODE.
PAY INCREASE TO MEDICAL
SUPERINTENDENTS SIR,-In his letter of July 9, Dr. Gore states that the revocation of Statutory Instrument 1948, no. 419, will mean that the responsibility of a medical superintendent of a mental hospital will be neither greater nor less than that of his fellow consultants. We know that the Minister has decided that the appointment of a superintendent shall no longer be compulsory, but it would be strange if he decided that when one is appointed he should not be permitted to superintend. Many consultants still think that a special-purpose hospital needs a doctor in day-to-day control, and would welcome the appointment of one of their colleagues to take this responsibility as an alternative to their being under the tutelage of a lay administrator. Whether the appointment should be on a temporary or permanent basis is a matter of opinion and does not affect the main i""l1f’-nnr does the nrnnosed
Northgate and District Hospital, Morpeth, Northumberland.
extra
f,25f).
C. GUY MILLMAN.
ADRENALECTOMY AND HYPOPHYSECTOMY SIR,-Ishould like to comment on Mr. Macbeth’s letter of June 25 advocating the transnasal approach to the pituitary fossa for the ablation of the normal pituitary gland. Neurological surgeons have, of course, been aware of this possibility since the first decade of the century and 167 of Cushing’s 260 operations for decompression of pituitary tumours were done by the transseptal trans-
sphenoidal route.4 The method was largely superseded by the transfrontal approach about 1928 but was revived by otolaryngologists, notably Hirsch, in the 1930s. Actuated by the same sentiments as those expressed by Mr. Macbeth-that the operation would be less disturbing, the convalescence smoother, and the hospital stay shorter-we operated on a group of patients in 1957 by the transsphenoidal route. We quickly became aware of the difference between the safe operation for the removal of a pituitary tumour in which the subarachnoid spaces in the area have been previously obliterated by tumour growth and the operation for complete removal of a normal pituitary gland which results in a free communication being established between the cerebrospinalfluid pathways round the pituitary stalk and the nasal sinuses. All
our
patients developed cerebrospinal-fluid rhinorrhoea,
of them a very troublesome recurring meningitis, and all of them were dead within five months of the operation. This might have been predicted from the high complication-rate following mechanical insertion of yttrium rods through the sinuses reported by Forrest,5 somewhat reduced by using two
3. 4. 5.
Scott, A. Personal communication, 1960. Cushing, H. J. Amer. med. Ass. 1914, 63, 1515. Forrest, A. P. M., et al. Brit. J. Surg. 1959, 47, 61.
GUIDE FOR PUDENDAL NERVE BLOCK
SIR,-Ishould like to confirm the merits of the guide for pudendal nerve block described by Dr. Eaton and Dr. Flanagan (June 25). It has been found most useful at Perivale Maternity Hospital and elsewhere during the past eighteen months. A transvaginal pudendal block is more quickly and accurately performed using this device and new house-surgeons learn the technique easily. The guide is now being made in this country by Messrs. Down Bros. and Mayer & Phelps, Mitcham, Surrey. The gauges described are American gauges, and the equivalent English ones are no. 17 and no.
20 respectively.
Perivale
Maternity Hospital, Greenford, Middlesex.
A. M. DICKINS.
THE CAUSE OF ŒDEMA IN " COR PULMONALE"
SIR,-May we comment on the suggestion of Dr. Campbell and Dr. Short (May 28) that oedema in cor pulmonale may be due to the increased bicarbonate reabsorption which is known to occur in the presence of a raised arterial carbon-dioxide tension ?
They have perhaps not considered that increased bicarbonate reabsorption need not be accompanied by increased sodium reabsorption, since bicarbonate ions may instead be substituted for chloride ions in the reabsorbate. That such sub,stitution does occur during the compensation of respiratory acidosis is clear from the plasma-electrolyte pattern in which, characteristically, the bicarbonate concentration is high, chloride low, and sodium normal. This elevation of plasmabicarbonate at the expense of chloride will not cause expansion of the extracellular fluid with oedema formation; for this to occur, not only bicarbonate reabsorption, but also sodium
reabsorption, must increase. Evidence concerning the effect of a high pCO2 on sodium reabsorption in otherwise normal humans is very difficult to obtain, because experimental subjects cannot tolerate severe or prolonged hypercapnoea. Such human experiments as have been performed have shown neither a significant rise in sodium reabsorption nor expansion of the extracellular fluid, but they involved relatively brief and modest elevations of carbon-dioxide tension.1-a Recent studies 45 in rats exposed to carbon-dioxide concentrations between 8 and 15 % for periods of up to eleven days have also shown no significant changes in urinary sodium or in sodium balance. It may be argued, however, that the rat is not a suitable experimental model. Information concerning the response in the dog is perhaps more pertinent, since in many respects the renal function of this animal more closely resembles that of man. In the paper on chronic respiratory acidosis in dogs by Sullivan and Dormant no data on sodium balance or sodium excretion during chronic hypercapncea were reported. However, we have recently completed balance studies in five dogs exposed to carbon-dioxide concentrations of 9 to 13% for periods of up to eight days. The sodium excretion was some1. Longson, D., Mills, J. N. J. Physiol. 1953, 122, 81. 2. Barbour, A., Bull, G. M., Evans, B. M., Hugh Jones, N. C., Logotheto3. 4. 5. 6.
poulos, J. Clin. Sci. 1953, 12, 1. Barker, E. S., Singer, R. B., Elkinton, J. R., Clark, J. K. J. clin. Invest. 1957, 36, 515. Levitin, H., Branscome, W., Epstein, F. H. ibid. 1958, 37, 1667. Carter, N. W., Seldin, D. W., Teng, H. C. ibid. 1959, 38, 949. Sullivan, W. J., Dorman, P. J. ibid. 1955, 34, 268.