POLIOMYELITIS VACCINE

576 be epidemic vertigo. By means of nystagmography and the more usual investigations, they support the view that the lesion is in the peripheral vestibular neurone or the brain-stem nuclei. Although nystagmography could not be generally applied, it would be interesting to refer more patients thought to have epidemic vertigo for caloric

tests, audiometry, electro-encephalography, and possibly

galvanic tests at an early stage of their illness, for none of these investigations is very burdensome to the patient. Treatment must clearly be empirical. The distressing vertigo can usually be relieved by rest in bed for a short period, and simple sedatives are usually sufficient until the trouble subsides. Nevertheless, the disease remains a challenge, and more energetic efforts to explain what it is may yield results which have a bearing on virus infections as a whole. PULMONARY FUNCTION AFTER PNEUMONECTOMY

AFTER

pneumonectomy without. thoracoplasty it might reasonably be expected that the volume of the remaining lung would increase, and that the consequent over-inflation would impair respiratory activity. In fact, lung volume does tend to increase, but there is often little change in the various criteria of respiratory efficacy. Thus, Cournand et aLl made a survey of ventilation-perfusion relationships and gas exchange in 16 patients after pneumonectomy, and found that distension did not inevitably follow ; even with some the the normal range. Friend,2 who examined 15 men before and after pneumonectomy, found evidence thatt the remaining lung increased in volume, but that the overinflation did not progress for more than three months. Over-inflation of itself had " no demonstrable adverse effect on ventilation " ; Friend also demonstrated postoperative respiratory insufficiency only in those patients who had chronic bronchitis, and he concluded that the maximum breathing capacity test could predict post-

degree of over-inflation and hyperventilation, respiratory performance was in the lower part of

operative dyspnoea. 3 Mcllroy and Bates examined 10 men, aged between 39 and 63, who had had a pneumonectomy from eight months to eight years before ; all operations had been done,

thoracoplasty,

for carcinoma of the bronchus. without They measured intraoesophageal pressure (as an index of intrathoracic pressure), so that lung compliance and flow-resistance could be estimated, and the pulmonary diffusing capacity (by the carbon-monoxide method) both at rest and during exercise on a treadmill. In 6 patients with little evidence of over-inflation of the lungs the results were what would be expected with In a halving of the tissue available for respiration. about half the patients, the compliance was less than that expected for one normal lung (i.e., there was a smaller increase in volume than normal for a given increase in pressure) and in most cases the compliance decreased more rapidly than normal as the lung volume increased. The respiratory work on exercise was greater than normal even when the lung was not over-inflated, and much greater when it was over-inflated; this might be expected since the ventilation of one lung alone is about double that of two lungs, for a given exercise-rate ; hence there would be a bigger resistive pressure component across the lung for a given rate of air-flow than there would be if there were two lungs to share the flow, with the correspondingly lower flowresistance offered by two sets of airways in parallel instead of one. This was in accordance with the finding of a mean inspiratory resistance greater than normal in all the patients. In 3 patients there was over-inflation (evidenced by a low intraoesophageal pressure and Cournand, A., Riley, R. L., Himmelstein, A., Austrian, J. thorac. Surg. 1950, 19, 80. 2. Friend, J. Lancet, 1954, ii, 260. 3. McIlroy, M. B., Bates, D. V. Thorax, 1956, 11, 303. 1.

R.

increased functional residual volume), but normal gas diffusion was maintained. 1 patient, eight years after operation, had a much over-inflated lung but normal end-expiratory pressure, indicating a loss of elastic recoil, and considerable impairment of gas diffusion with a ventilation higher than normal fora given oxygen uptake ;; he could be considered to have

grossly

emphysema. Thus, the absence of one lung may result in very little change in the function of the other ; but, since only one lung is left to bear the respiratory burden, there is a tendency to over-inflation. A low intrathoracic pressure leads not only to over-inflation but also to a fall in compliance. The tendency then is for the lung to lose elasticity, with a consequent rise in intrathoracic pressure and functional residual capacity, and a relative fall in diffusing capacity ; gas distribution, however, is little deranged, differentiating the condition from classical emphysema secondary to long-standing bronchitis.

Mcllroy and Bates began their investigation with three questions in mind. The first was whether over. inflation led to dyspnoea through changes in the mechanical properties of the lungs ;they presume that postoperative dyspnoea is due to the necessary over. ventilation of the remaining lung, and that over. inflation accentuates the dyspneea by a further reduction in compliance. The second question was whether the diffusing capacity was lowered, and if so what were the results ;; they found it was generally half the value in normal people, and this reduction means a greater ventilation for a given oxygen uptake. The relation between over-inflation and emphysema constituted the third question ; and the results suggested a clear distinction between these two conditions, for over. inflation results in an increased lung volume witha low intrathoracic pressure level and normal gas diffusion, Emphysema, on the other hand, is characterised by an increased lung volume with a normal intrathoracic pressure level and impaired diffusion." POLIOMYELITIS VACCINE THE colour change in a few vials of poliomyelitis vaccine during storage1 has been traced to contamination. In a letter to medical officers of health, Sir John Charles, chief medical officer of the Ministry of Health, says that faulty containers were to blame and the contaminant was a non-pathogenic Pseudomonas jluorescens, Repeat sterility tests on the remainder of the batch have been negative. After incubation at 37°C, 25°C, and roomtemperature, normally coloured vaccine showed no discoloration. It has therefore been decided to proceed with the issue of this batch of vaccine. "

THE Q. J. M. IN 1907, at the first meeting of the Association of Physicians of Great Britain and Ireland, plans were made to establish a medical journal to publish "papers which, though scientifically important, were not suitable for the Journals, nor for the clinical or pathological societies." The name first chosen was Archives of Jledicine, but there must have been objections to that title, for it was soon changed to one now familiar whereever medical journals are read-The Quarterly Journal of 3Tedicine. The energy of William Osler, for 12 years its editor, gave the new venture a flying start, and in the succeeding 50 years of vigorous life it has been ably served by a distinguished line of editors. We congratulate them and all who have helped them to attain this anniversary. To mark the occasion an attractive jubilee number has just been published, and in an opening article Sir Russell Brain recounts the history of the association and the journal and mentions some of the memorable names connected with them. 1. See Lancet, March

9, 1957, p. 518.